rfc9923.original.xml   rfc9923.xml 
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<rfc <rfc xmlns:xi="http://www.w3.org/2001/XInclude" category="info" docName="draft-e
xmlns:xi="http://www.w3.org/2001/XInclude" astlake-fnv-35" number="9923" ipr="trust200902" obsoletes="" updates="" submissi
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one of std, bcp, info, exp, historic * ipr should be one of
trust200902, noModificationTrust200902, noDerivativesTrust200902,
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obsoletes can be an RFC number as NNNN
<!-- ____________________FRONT_MATTER____________________ -->
<front> <front>
<title abbrev="FNV">The FNV Non-Cryptographic Hash <title abbrev="FNV">The FNV Non-Cryptographic Hash Algorithm</title>
Algorithm</title> <seriesInfo name="RFC" value="9923"/>
<!-- The abbreviated title is required if the full title is
longer than 39 characters -->
<seriesInfo name="Internet-Draft"
value="&filename;"/>
<author fullname="Glenn S. Fowler" initials="G." <author fullname="Glenn S. Fowler" initials="G." surname="Fowler">
surname="Fowler">
<organization>Google</organization> <organization>Google</organization>
<address> <address>
<email>glenn.s.fowler@gmail.com</email> <email>glenn.s.fowler@gmail.com</email>
</address> </address>
</author> </author>
<author fullname="Landon Curt Noll" initials="L." <author fullname="Landon Curt Noll" initials="L." surname="Noll">
surname="Noll">
<organization>Cisco Systems</organization> <organization>Cisco Systems</organization>
<address> <address>
<postal> <postal>
<street>170 West Tasman Drive</street> <street>170 West Tasman Drive</street>
<city>San Jose</city> <city>San Jose</city>
<region>California</region> <region>California</region>
<code>95134</code> <code>95134</code>
<country>USA</country> <country>United States of America</country>
</postal> </postal>
<phone>+1-408-424-1102</phone> <phone>+1-408-424-1102</phone>
<email>fnv-ietf7-mail@asthe.com</email> <email>fnv-ietf8-mail@asthe.com</email>
<uri>http://www.isthe.com/chongo/index.html</uri> <uri>http://www.isthe.com/chongo/index.html</uri>
</address> </address>
</author> </author>
<author fullname="Kiem-Phong Vo" initials="K." <author fullname="Kiem-Phong Vo" initials="K." surname="Vo">
surname="Vo">
<organization>Google</organization> <organization>Google</organization>
<address> <address>
<email>phongvo@gmail.com</email> <email>phongvo@gmail.com</email>
</address> </address>
</author> </author>
<author fullname="Donald E. Eastlake 3rd" initials="D." <author fullname="Donald E. Eastlake 3rd" initials="D." surname="Eastlake 3rd
surname="Eastlake"> ">
<organization>Independent</organization> <organization>Independent</organization>
<address> <address>
<postal> <postal>
<street>2386 Panoramic Circle</street> <street>2386 Panoramic Circle</street>
<city>Apopka</city> <city>Apopka</city>
<region>Florida</region> <region>Florida</region>
<code>32703</code> <code>32703</code>
<country>USA</country> <country>United States of America</country>
</postal> </postal>
<phone>+1-508-333-2270</phone> <phone>+1-508-333-2270</phone>
<email>d3e3e3@gmail.com</email> <email>d3e3e3@gmail.com</email>
</address> </address>
</author> </author>
<author fullname="Tony Hansen" initials="T." <author fullname="Tony Hansen" initials="T." surname="Hansen">
surname="Hansen">
<organization>AT&amp;T</organization> <organization>AT&amp;T</organization>
<address> <address>
<postal> <postal>
<street>200 Laurel Avenue South</street> <street>200 Laurel Avenue South</street>
<city>Middletown</city> <city>Middletown</city>
<region>New Jersey</region> <region>New Jersey</region>
<code>07748</code> <code>07748</code>
<country>USA</country> <country>United States of America</country>
</postal> </postal>
<email>tony@att.com</email> <email>tony@att.com</email>
</address> </address>
</author> </author>
<date year="2025" month="6" day="6"/> <date year="2025" month="December"/>
<area/>
<workgroup>Network Working Group</workgroup>
<!-- "Internet Engineering Task Force" is fine for individual
submissions. If this element is not present, the default is
"Network Working Group", which is used by the RFC Editor as a
nod to the history of the RFC Series. -->
<keyword></keyword>
<!-- Multiple keywords are allowed. Keywords are incorporated
into HTML output files for use by search engines. -->
<abstract> <abstract>
<t>FNV (Fowler/Noll/Vo) is a fast, non-cryptographic hash algorithm <t>FNV (Fowler/Noll/Vo) is a fast, non-cryptographic hash algorithm
with good dispersion that has been widely used and is referenced in a with good dispersion that has been widely used and is referenced in a
number of standards documents. The purpose of this document is to number of standards documents. The purpose of this document is to
make information on FNV and open-source code performing all make information on FNV and open-source code performing all
specified sizes of FNV conveniently available to the Internet specified sizes of FNV conveniently available to the Internet
community.</t> community.</t>
</abstract> </abstract>
</front> </front>
<!-- ____________________MIDDLE_MATTER____________________ -->
<middle> <middle>
<section> <!-- 1. --> <section>
<name>Introduction</name> <name>Introduction</name>
<t>FNV (Fowler/Noll/Vo) hashes are designed to be fast and have a <t>FNV (Fowler/Noll/Vo) hashes are designed to be fast and have a
small code footprint. Their good dispersion makes them particularly small code footprint. Their good dispersion makes them particularly
well-suited for hashing nearly identical strings, including URLs, well suited for hashing nearly identical strings, including URLs,
hostnames, filenames, text, and IP and MAC addresses. Their speed hostnames, filenames, text, and IP and Media Access Control (MAC) addresses. T
heir speed
allows one to quickly hash lots of data.</t> allows one to quickly hash lots of data.</t>
<t>The purpose of this document is to make information on FNV and <t>The purpose of this document is to make information on FNV and
open-source code performing all specified sizes of FNV conveniently open-source code performing all specified sizes of FNV conveniently
available to the Internet community. This work is not an Internet available to the Internet community. This work is not an Internet
standard and is not the result of consensus of the IETF Standard and does not have the consensus of the IETF community.</t>
community.</t>
<section anchor="applicability"> <!-- 1.1 --> <section>
<name>Conventions Used in This Document</name>
<t>The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>",
"<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>",
"<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>",
"<bcp14>SHOULD NOT</bcp14>",
"<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
"<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document
are to be interpreted as described in BCP&nbsp;14
<xref target="RFC2119"/> <xref target="RFC8174"/> when, and only
when, they appear in all capitals, as shown here.</t>
</section>
<section anchor="applicability">
<name>Applicability of Non-Cryptographic Hashes and FNV</name> <name>Applicability of Non-Cryptographic Hashes and FNV</name>
<t>While a general theory of hash function strength and utility is <t>While a general theory of hash function strength and utility is
beyond the scope of this document, typical attacks on hash function beyond the scope of this document, typical attacks on hash functions
involve one of the following:</t> involve one of the following:</t>
<dl> <dl spacing="normal" newline="false">
<dt>Collision:</dt><dd>Finding two data inputs that yield the same <dt>Collision:</dt><dd>Finding two data inputs that yield the same
hash output.</dd> hash output.</dd>
<dt>First Pre-Image:</dt><dd>Given a hash output, finding a data <dt>First Pre-Image:</dt><dd>Given a hash output, finding a data
input that hashes to that output.</dd> input that hashes to that output.</dd>
<dt>Second Pre-Image:</dt><dd>Given a first data input, finding a <dt>Second Pre-Image:</dt><dd>Given a first data input, finding a
second input that produces the same hash output as the first.</dd> second input that produces the same hash output as the first.</dd>
</dl> </dl>
<t>For a hash function producing N bits, there necessarily will be <t>For a hash function producing N bits, there necessarily will be
collisions among the hashes of more than 2**N distinct inputs. And collisions among the hashes of more than 2**N distinct inputs. And
if the hash function can produce hashes covering all 2**N possible if the hash function can produce hashes covering all 2**N possible
outputs, then there will exist first and second pre-images. FNV is outputs, then there will exist first and second pre-images. FNV is
NOT RECOMMENDED for any application that requires that it be <bcp14>NOT RECOMMENDED</bcp14> for any application that requires that it be
computationally infeasible to succeed in one of the above computationally infeasible for one of the above types of
attacks.</t> attacks to succeed.</t>
<t>FNV hashes are generally not applicable for use when faced with <t>FNV hashes are generally not applicable for use when faced with
an active adversary in a security scheme where the modest effort an active adversary in a security scheme where the modest effort
required to compute FNV hashes (see <xref target="Effort"/>) and required to compute FNV hashes (see <xref target="Effort"/>) and
their other noncryptographic characteristics (see <xref their other non-cryptographic characteristics (see <xref
target="noncrypto"/>) would make the scheme ineffective against the target="noncrypto"/>) would make the scheme ineffective against the
threat model being considered. It is sometimes hard to determine threat model being considered. It is sometimes hard to determine
whether or not there are attack vectors via a hash.</t> whether or not there are attack vectors via a hash.</t>
<t>For a discussion of adversarial inducement of collisions, see <t>For a discussion of adversarial inducement of collisions, see
<xref target="bang"/>.</t> <xref target="bang"/>.</t>
</section> </section>
<section anchor="Uses"> <section anchor="Uses">
<name>FNV Hash Uses</name> <name>FNV Hash Uses</name>
<t>The FNV hash has been widely used. Examples include the <t>The FNV hash has been widely used. Examples include the
following:</t> following:</t>
<ul> <ul>
<li>NFS implementations (e.g., FreeBSD 4.3 <xref <li>NFS implementations (e.g., FreeBSD 4.3 <xref
target="FreeBSD"/>, IRIX, Linux (NFS v4)),</li> target="FreeBSD"/>, IRIX, Linux (NFS v4)),</li>
<li>text based referenced resources for video games on the PS2, <li>text-based referenced resources for video games on the PS2,
Gamecube, and XBOX</li> Gamecube, and XBOX,</li>
<li><xref target="Cohesia"/> MASS project server collision <li>Cohesia MASS project server collision avoidance <xref target="Cohesia"
avoidance,</li> />,</li>
<li>to improve the fragment cache <xref target="FragCache"/> at <li>to improve the fragment cache <xref target="FragCache"/> at
X (formerly Twitter),</li> X (formerly Twitter),</li>
<li>the flatassembler open source x86 assembler - user-defined <li>the flatassembler open-source x86 assembler - user-defined
symbol hashtree <xref target="flatassembler"/>,</li> symbol hashtree <xref target="flatassembler"/>,</li>
<li>Used in the speed-sensitive guts of <xref <li>used in the speed-sensitive guts of <xref
target="twistylists"/>, an open-source structured namespace target="twistylists"/>, an open-source structured namespace
manager,</li> manager,</li>
<li>database indexing hashes,</li> <li>database indexing hashes,</li>
<li>PowerBASIC <xref target="BASIC"/> inline assembly routine,</li> <li>PowerBASIC inline assembly routine <xref target="BASIC"/>,</li>
<li>major web search / indexing engines,</li> <li>major web search / indexing engines,</li>
<li>the <xref target="calc"/> calculator,</li> <li>the "calc" C-style calculator <xref target="calc"/>,</li>
<li>netnews history file Message-ID lookup functions,</li> <li>netnews history file Message-ID lookup functions,</li>
<li><xref target="FRET"/> - a tool to identify file data <li><xref target="FRET"/> - a tool to identify file data
structures / helps to understand file formats</li> structures / help understand file formats,</li>
<li>anti-spam filters,</li> <li>anti-spam filters,</li>
<li>used in an implementation of libketama for use in items <li>used in an implementation of libketama <xref target="libketama"/> for use in items
such as <xref target="memcache"/>,</li> such as <xref target="memcache"/>,</li>
<li>a spellchecker programmed in Ada 95,</li> <li>a spellchecker programmed in Ada 95,</li>
<li>used in the BSD IDE project <xref target="fasmlab"/>,</li> <li>used in the BSD Integrated Development Environments (IDE) project <xre f target="fasmlab"/>,</li>
<li>non-cryptographic file fingerprints,</li> <li>non-cryptographic file fingerprints,</li>
<li>used in the deliantra game server for its shared <li>used in the deliantra game server for its shared
string implementation <xref target="deliantra"/></li> string implementation <xref target="deliantra"/>,</li>
<li>computing Unique IDs in DASM (DTN (Delay Tolerant <li>computing Unique IDs in DASM (DTN (Delay Tolerant
Networking) Applications for Symbian Mobile-phones),</li> Networking) Applications for Symbian Mobile-phones),</li>
<li>Microsoft's hash_map implementation for VC++ 2005,</li> <li>Microsoft's hash_map implementation for VC++ 2005,</li>
<li>the realpath cache in PHP 5.x <li>the realpath cache in PHP 5.x
(php-5.2.3/TSRM/tsrm_virtual_cwd.c),</li> (php-5.2.3/TSRM/tsrm_virtual_cwd.c),</li>
<li>DNS (Domain Name System) servers,</li> <li>DNS (Domain Name System) servers,</li>
<li>used to improve <xref target="Leprechaun"/>, an extremely <li>used to improve <xref target="Leprechaun"/>, an extremely
fast word list creator,</li> fast wordlist creator,</li>
<li>the <xref target="Vely"/> framework for C language,</li> <li>the Smash utility <xref target="Smash"/> for rapidly finding duplicate
<li>Golf language hash tables <xref target="GolfHash"/>,</li> files,</li>
<li>the libstr logging library <xref target="libstr"/>,</li> <li>Golf language hash tables <xref target="RimStone"/>,</li>
<li>a standard library for modern fortran <xref <li>the libsir logging library <xref target="libsir"/>,</li>
<li>a standard library for modern Fortran <xref
target="Fortran"/>,</li> target="Fortran"/>,</li>
<li>to help seeding a pseudo random number generator <xref
target="Vortetty"/>,</li>
</ul> </ul>
<t>and many other uses. It is also referenced in the <xref <t>and many other uses. It is also referenced in the following standards do
target="RFC7357"/>, <xref target="RFC7873"/>, and <xref cuments: <xref target="RFC7357"/>, <xref target="RFC7873"/>, and <xref
target="IEEE8021Qbp"/> standards documents.</t> target="IEEE8021Q-2022"/>.</t>
<t>A study has recommended FNV in connection with the IPv6 Flow <t>A study has recommended FNV in connection with the IPv6 flow
Label field <xref target="IPv6flow"/>. Additionally, there was a label value <xref target="IPv6flow"/>. Additionally, there was a
proposal to use FNV for BFD sequence number generation <xref proposal to use FNV for Bidirectional Forwarding Detection (BFD) sequence numb
target="BFDseq"/> and a recent article and study on er generation <xref
non-cryptographic hash functions <xref target="NCHF"/>.</t> target="BFDseq"/>. <xref target="NCHF"/> discusses criteria for evaluating non
-cryptographic hash
functions.</t>
<t>If you use an FNV function in an application, you are kindly <t>If you use an FNV function in an application, you are kindly
requested to send an EMail about it to requested to send an email about it to
&lt;fnvhash-mail@asthe.com&gt; with "FNV hash function" forming &lt;fnvhash-mail@asthe.com&gt; with "FNV hash function" forming
part of the subject line.</t> part of the subject line.
<!-- [rfced] Section 1.2: Please confirm that
<fnvhash-mail@asthe.com> is still a valid, working email address.
Original:
If you use an FNV function in an application, you are kindly
requested to send an EMail about it to <fnvhash-mail@asthe.com> with
"FNV hash function" forming part of the subject line.
Donald Eastlake: I'll let other authors respond on that. -->
</t>
</section> </section>
<section anchor="noncrypto"> <section anchor="noncrypto">
<name>Why is FNV Non-Cryptographic?</name> <name>Why Is FNV Non-Cryptographic?</name>
<t>A full discussion of cryptographic hash requirements and strength <t>A full discussion of cryptographic hash requirements and strength
is beyond the scope of this document. However, here are three is beyond the scope of this document. However, here are three
characteristics of FNV that would generally be considered to make it characteristics of FNV that would generally be considered to make it
non-cryptographic:</t> non-cryptographic:</t>
<ol> <ol spacing="normal">
<li>Sticky State - A cryptographic hash should not have a state in <li>Sticky State - A cryptographic hash should not have a state in
which it can stick for a plausible input pattern. But, in the very which it can stick for a plausible input pattern. But in the very
unlikely event that the FNV hash variable accidentally becomes zero unlikely event that the FNV hash variable accidentally becomes zero
and the input is a sequence of zero bytes, the hash variable will and the input is a sequence of zero bytes, the hash variable will
remain at zero until there is a non-zero input byte and the final remain at zero until there is a non-zero input byte and the final
hash value will be unaffected by the length of that sequence of zero hash value will be unaffected by the length of that sequence of zero
input bytes. For the common case of fixed length input, this would input bytes. For the common case of fixed-length input, this would
usually not be significant because the number of non-zero bytes usually not be significant because the number of non-zero bytes
would vary inversely with the number of zero bytes and for some would vary inversely with the number of zero bytes and for some
types of input, runs of zeros do not occur. Furthermore, the use of types of input, runs of zeros do not occur. Furthermore, the use of
a different offset_basis or the inclusion of even a little a different offset_basis or the inclusion of even a little
unpredictable input may be sufficient, under some circumstances, to unpredictable input may be sufficient, under some circumstances, to
stop an adversary from inducing a zero hash variable (see <xref stop an adversary from inducing a zero hash variable (see <xref
target="bang"/>).</li> target="bang"/>).</li>
<li>Diffusion - Every output bit of a cryptographic hash should be <li>Diffusion - Every output bit of a cryptographic hash should be
an equally complex function of every input bit. But it is easy to an equally complex function of every input bit. But it is easy to
see that the least significant bit of a direct FNV hash is the XOR see that the least significant bit of a direct FNV hash is the XOR
of the least significant bits of every input byte and does not of the least significant bits of every input byte and does not
depend on any other input bits. While more complex, the second depend on any other input bits. While more complex, the second
through seventh least significant bits of an FNV hash have a similar through seventh least significant bits of an FNV hash have a similar
weakness; only the top bit of the bottom byte of output, and higher weakness; only the top bit of the bottom byte of output, and higher-order bits
order bits, depend on all input bits. If these properties are , depend on all input bits. If these properties are
considered a problem, they can be easily fixed by XOR folding (see considered a problem, they can be easily fixed by XOR folding (see
<xref target="fold"/>).</li> <xref target="fold"/>).</li>
<li>Work Factor - Depending on intended use, it is frequently <li>Work Factor - Depending on intended use, it is frequently
desirable that a hash function should be computationally expensive desirable that a hash function should be computationally expensive
for general purpose and graphics processors since these may be for general-purpose and graphics processors, since these may be
profusely available through elastic cloud services or botnets. This profusely available through elastic cloud services or botnets. This
is to slow down testing of possible inputs if the output is known or is applied to slow down testing of possible inputs if the output is known or
the like. But FNV is designed to be inexpensive on a general-purpose the like. But FNV is designed to be inexpensive on a general-purpose
processor. (See <xref target="Effort"/>.)</li> processor (see <xref target="Effort"/>).</li>
</ol> </ol>
<t>Nevertheless, none of the above have proven to be a problem in <t>Nevertheless, none of the above have proven to be a problem in
actual practice for the many non-cryptographic applications of FNV actual practice for the many non-cryptographic applications of FNV
(see <xref target="Uses"/>).</t> (see <xref target="Uses"/>).</t>
</section> </section>
</section> <!-- end 1. Introduction --> </section>
<section> <!-- 2. --> <section>
<name>FNV Basics</name> <name>FNV Basics</name>
<t>This document focuses on the FNV-1a function whose pseudo-code is <t>This document focuses on the FNV-1a function, whose pseudocode is
as follows:</t> as follows:</t>
<sourcecode type="pseudocode"> <sourcecode type="pseudocode"><![CDATA[
hash = offset_basis hash = offset_basis
for each octet_of_data to be hashed for each octet_of_data to be hashed
hash = hash xor octet_of_data hash = hash XOR octet_of_data
hash = hash * FNV_Prime mod 2**HashSize hash = hash * FNV_Prime mod 2**HashSize
return hash return hash
</sourcecode> ]]></sourcecode>
<t>In the pseudo-code above, hash is a power-of-two number of bits <t>In the pseudocode above, hash is a power-of-2 number of bits
(HashSize is 32, 64, 128, 256, 512, or 1024) and offset_basis and (HashSize is 32, 64, 128, 256, 512, or 1024), and offset_basis and
FNV_Prime depend on the size of hash.</t> FNV_Prime depend on the size of hash.</t>
<t>The FNV-1 algorithm is the same, including the values of <t>The FNV-1 algorithm is the same, including the values of
offset_basis and FNV_Prime, except that the order of the two lines offset_basis and FNV_Prime, except that the order of the two lines
with the "xor" and multiply operations are reversed. Operational with the "XOR" and multiply operations is reversed. Operational
experience indicates better hash dispersion for small amounts of data experience indicates better hash dispersion for small amounts of data
with FNV-1a. FNV-0 is the same as FNV-1 but with offset_basis set to with FNV-1a. FNV-0 is the same as FNV-1 but with offset_basis set to
zero. FNV-1a is suggested for general use.</t> zero. FNV-1a is suggested for general use.</t>
<section> <!-- 2.1 --> <section>
<name>FNV Primes</name> <name>FNV Primes</name>
<t>The theory behind FNV_Prime's is beyond the scope of this document <t>The theory behind FNV_Primes is beyond the scope of this document,
but the basic property to look for is how an FNV_Prime would impact but the basic property to look for is how an FNV_Prime would impact
dispersion. Now, consider any n-bit FNV hash where n >= 32 and is also dispersion. Now, consider any n-bit FNV hash where n >= 32 and is also
a power of 2, in particular n = 2**s. For each such n-bit FNV hash, an a power of 2 -- in particular, n = 2**s. For each such n-bit FNV hash, an
FNV_Prime p is defined as:</t> FNV_Prime p is defined as follows:</t>
<ul> <ul>
<li><t>When s is an integer and 4 &lt; s &lt; 11, then <li><t>When s is an integer and 4 &lt; s &lt; 11,
FNV_Prime is the smallest prime p of the form:</t> FNV_Prime is the smallest prime p of the form:</t>
<artwork align="center"> <artwork align="left"><![CDATA[ 256**int((5 + 2**s)/12) + 2**8
256**int((5 + 2**s)/12) + 2**8 + b + b
</artwork> ]]></artwork>
</li> </li>
<li><t>where b is an integer such that:</t> <li><t>where b is an integer such that:</t>
<artwork align="center"> <artwork align="left"><![CDATA[ 0 < b < 2**8
0 &lt; b &lt; 2**8 ]]></artwork>
</artwork>
</li> </li>
<li><t>The number of one-bits in b is 4 or 5</t></li> <li><t>The number of one bits in b is four or five</t></li>
<li><t>and where</t> <li><t>and where</t>
<artwork align="center"> <artwork align="left"><![CDATA[ ( p mod (2**40 - 2**24 - 1) ) > ( 2**24 + 2
( p mod (2**40 - 2**24 - 1) ) > ( 2**24 + 2**8 + 2**7 ) **8 + 2**7 )
</artwork> ]]></artwork>
</li> </li>
</ul> </ul>
<t>Experimentally, FNV_Primes matching the above constraints tend to <t>Experimentally, FNV_Primes matching the above constraints tend to
have better dispersion properties. They improve the polynomial have better dispersion properties. They improve the polynomial
feedback characteristic when an FNV_Prime multiplies an intermediate feedback characteristic when an FNV_Prime multiplies an intermediate
hash value. As such, the hash values produced are more scattered hash value. As such, the hash values produced are more scattered
throughout the n-bit hash space.</t> throughout the n-bit hash space.</t>
<t>The case where s &lt; 5 is not considered due to the resulting low <t>The case where s &lt; 5 is not considered due to the resulting low
hash quality. Such small hashes can, if desired, be derived from a 32 hash quality. Such small hashes can, if desired, be derived from a
bit FNV hash by XOR folding (see <xref target="fold"/>). The case 32-bit FNV hash by XOR folding (see <xref target="fold"/>). The case
where s > 10 is not considered because of the doubtful utility of such where s > 10 is not considered because of the doubtful utility of such
large FNV hashes and because the criteria for such large FNV_Primes is large FNV hashes and because the criteria for such large FNV_Primes would
more complex, due to the sparsity of such large primes, and would be more complex, due to the sparsity of such large primes, and would
needlessly clutter the criteria given above.</t> needlessly clutter the criteria given above.</t>
<t>Per the above constraints, an FNV_Prime should have only 6 or 7 <t>Per the above constraints, an FNV_Prime should have only six or seven
one-bits in it: one relatively high order one bit, the 2**9 bit, and 4 one bits in it: one relatively high-order one bit, the 2**9 bit, and four
or 5 one bits in the low order byte. Therefore, some compilers may or five one bits in the low-order byte. Therefore, some compilers may
seek to improve the performance of a multiplication with an FNV_Prime seek to improve the performance of a multiplication with an FNV_Prime
by replacing the multiplication with shifts and adds. However, the by replacing the multiplication with shifts and adds. However, the
performance of this substitution is highly hardware-dependent and performance of this substitution is highly hardware dependent and
should be done with care. The selection of FNV_Primes prioritizes the should be done with care. The selection of FNV_Primes prioritizes the
quality of the resulting hash function, not compiler optimization quality of the resulting hash function, not compiler optimization
considerations.</t> considerations.</t>
</section> </section>
<section anchor="constoffb"> <!-- 2.2 --> <section anchor="constoffb">
<name>FNV offset_basis</name> <name>FNV offset_basis</name>
<t>The offset_basis values for the n-bit FNV-1a algorithms are <t>The offset_basis values for the n-bit FNV-1a algorithms are
computed by applying the n-bit FNV-0 algorithm to the following computed by applying the n-bit FNV-0 algorithm to the following
32-octet ASCII <xref target="RFC0020"/> character string:</t> 32-octet ASCII <xref target="RFC0020"/> character string:</t>
<artwork align="center" type="ascii-art"> <artwork align="left"><![CDATA[ chongo <Landon Curt Noll> /\
chongo &lt;Landon Curt Noll> /\../\ ../\
</artwork> ]]></artwork>
<t>or, in <xref target="C"/> notation, the following string:</t> <t>or, in C notation <xref target="C"/>, the following string:</t>
<artwork align="center" type="ascii-art"> <artwork align="left"><![CDATA[ "chongo <Landon Curt Noll> /\
"chongo &lt;Landon Curt Noll> /\\../\\" \../\\"
</artwork> ]]></artwork>
<t>In the general case, almost any offset_basis would serve as long as <t>In the general case, almost any offset_basis would serve as long as
it is non-zero. However, FNV hashes calculated with different it is non-zero. However, FNV hashes calculated with different
offset_basis values will not interoperate. The choice of a offset_basis values will not interoperate. The choice of a
non-standard offset_basis may be beneficial in some limited non-standard offset_basis may be beneficial in some limited
circumstances to defend against attacks that try to induce hash circumstances to defend against attacks that try to induce hash
collisions as discussed in <xref target="bang"/>. Any entity that can collisions as discussed in <xref target="bang"/>. Any entity that can
observe the FNV hash output, and can cause the null string (the string observe the FNV hash output and can cause the null string (the string
of length zero) to be hashed, will thereby be able to directly observe of length zero) to be hashed will thereby be able to directly observe
the offset_basis which will be the hash output.</t> the offset_basis which will be the hash output.
</t>
</section> </section>
<section anchor="endian"> <!-- 2.3 --> <section anchor="endian">
<name>FNV Endianism</name> <name>FNV Endianism</name>
<t>For persistent storage or interoperability between different <t>For persistent storage or interoperability between different
hardware platforms, an FNV hash shall be represented in the little hardware platforms, an FNV hash shall be represented in the
endian format <xref target="IEN137"/>. That is, the FNV hash will be little-endian format <xref target="IEN137"/>. That is, the FNV hash will be
stored in an array hash[N] with N bytes such that its integer value stored in an array hash[N] with N bytes such that its integer value
can be retrieved as follows:</t> can be retrieved as follows:</t>
<sourcecode type="C"> <sourcecode type="c"><![CDATA[
unsigned char hash[N]; unsigned char hash[N];
for ( i = N-1, value = 0; i >= 0; --i ) for ( i = N-1, value = 0; i >= 0; --i )
value = ( value &lt;&lt; 8 ) + hash[i]; value = ( value << 8 ) + hash[i];
</sourcecode> ]]></sourcecode>
<t>However, when FNV hashes are used in a single process or a group <t>However, when FNV hashes are used in a single process or a group
of processes sharing memory on processors with compatible endian-ness, of processes sharing memory on processors with compatible endianness,
the natural endian-ness of those processors can be used, as long as it the natural endianness of those processors can be used, as long as it
is used consistently, regardless of its type, little, big, or some is used consistently, regardless of its type -- little, big, or some
other exotic form.</t> other exotic form.</t>
<t>The code provided in Section 6 has FNV hash functions that return a <t>The code provided in <xref target="SourceCode"/> has FNV hash functions that
little endian byte vector for all lengths. Because they are more return a
little-endian byte vector for all lengths. Because they are more
efficient, the code also provides functions that return FNV hashes as efficient, the code also provides functions that return FNV hashes as
32-bit integers or, where supported, 64-bit integers, for those sizes 32-bit integers or, where supported, 64-bit integers, for those sizes
of FNV hash. Such integers are compatible with the same size byte of FNV hash. Such integers are compatible with the same-size byte
vectors on little endian computers but use of the functions returning vectors on little-endian computers, but the use of the functions returning
integers on big endian or other non-little-endian machines will be integers on big-endian or other non-little-endian machines will be
byte-reversed or otherwise incompatible with the byte vector return byte-reversed or otherwise incompatible with the byte vector return
values.</t> values.</t>
</section> </section>
</section> <!-- 2. --> </section>
<section anchor="fold"> <!-- 3. --> <section anchor="fold">
<name>Other Hash Sizes and XOR Folding</name> <name>Other Hash Sizes and XOR Folding</name>
<t>Many hash uses require a hash that is not one of the FNV sizes for <t>Many hash uses require a hash that is not one of the FNV sizes for
which constants are provided in <xref target="const"/>. If a larger which constants are provided in <xref target="const"/>. If a larger
hash size is needed, please contact the authors of this document.</t> hash size is needed, please contact the authors of this document.</t>
<t>For scenarios where a fixed-size binary field of k bits is desired <t>For scenarios where a fixed-size binary field of k bits is desired
with k &lt; 1024 but not among the provided constants in Section 5, with k &lt; 1024 but not among the constants provided in <xref target="const"/>,
the recommended approach involves using the smallest FNV hash of size the recommended approach involves using the smallest FNV hash of size
S where S > k and employing xor folding, as shown below. The final S where S > k and employing XOR folding, as shown below. The final
bit masking operation is logically unnecessary if the size of the bit-masking operation is logically unnecessary if the size of the
variable k-bit-hash is exactly k bits.</t> variable k-bit-hash is exactly k bits.</t>
<sourcecode type="pseudocode"> <sourcecode type="pseudocode"><![CDATA[
temp = FNV_S ( data-to-be-hashed ) temp = FNV_S ( data-to-be-hashed )
k-bit-hash = ( temp xor temp>>k ) bitwise-and ( 2**k - 1 ) k-bit-hash = ( temp XOR temp>>k ) bitwise-and ( 2**k - 1 )
</sourcecode> ]]></sourcecode>
<t>A somewhat stronger hash may be obtained for exact FNV sizes by <t>A somewhat stronger hash may be obtained for exact FNV sizes by
calculating an FNV twice as long as the desired output ( S = 2*k ) and calculating an FNV twice as long as the desired output ( S = 2*k ) and
performing such xor data folding using a k equal to the size of the performing such XOR data folding using a k equal to the size of the
desired output. However, if a much stronger hash is desired, desired output. However, if a much stronger hash is desired,
cryptographic algorithms, such as those in <xref target="FIPS202"/> or cryptographic algorithms, such as those specified in <xref target="FIPS202"/> or
<xref target="RFC6234"/>, should be used.</t> <xref target="RFC6234"/>, should be used.</t>
<t>If it is desired to obtain a hash result that is a value between 0 <t>If it is desired to obtain a hash result that is a value between 0
and max, where max+1 is a not a power of two, simply choose an FNV and max, where max+1 is not a power of 2, simply choose an FNV
hash size S such that 2**S > max. Then calculate the following:</t> hash size S such that 2**S > max. Then, calculate the following:</t>
<artwork align="center"> <artwork align="left"><![CDATA[ FNV_S mod ( max+1 )
FNV_S mod ( max+1 ) ]]></artwork>
</artwork>
<t>The resulting remainder will be in the range desired but will <t>The resulting remainder will be in the range desired but will
suffer from a bias against large values with the bias being larger if suffer from a bias against large values, with the bias being larger if
2**S is only a little bigger than max. If this bias is acceptable, no 2**S is only slightly larger than max. If this bias is acceptable, no
further processing is needed. If this bias is unacceptable, it can be further processing is needed. If this bias is unacceptable, it can be
avoided by retrying for certain high values of hash, as follows, avoided by retrying for certain high values of hash, as follows,
before applying the mod operation above:</t> before applying the mod operation above:</t>
<sourcecode type="pseudocode"> <sourcecode type="pseudocode"><![CDATA[
X = ( int( ( 2**S - 1 ) / ( max+1 ) ) ) * ( max+1 ) X = ( int( ( 2**S - 1 ) / ( max+1 ) ) ) * ( max+1 )
while ( hash >= X ) while ( hash >= X )
hash = ( hash * FNV_Prime ) + offset_basis hash = ( hash * FNV_Prime ) + offset_basis
</sourcecode> ]]></sourcecode>
</section> <!-- 3 --> </section>
<section> <!-- 4. --> <section anchor="sec-4">
<name>Hashing Multiple Values Together</name> <name>Hashing Multiple Values Together</name>
<t>Sometimes there are multiple different component values, say three <t>Sometimes, there are multiple different component values, say three
strings X, Y, and Z, where a hash over all of them is desired. The strings X, Y, and Z, where a hash over all of them is desired. The
simplest thing to do is to concatenate them in a fixed order and simplest thing to do is to concatenate them in a fixed order and
compute the hash of that concatenation, as in</t> compute the hash of that concatenation, as in</t>
<artwork align="center"> <artwork align="left"><![CDATA[ hash ( X | Y | Z )
hash ( X | Y | Z ) ]]></artwork>
</artwork>
<t>where the vertical bar character ("|") represents string <t>where the vertical bar character ("|") represents string
concatenation. If the components being combined are of variable concatenation. If the components being combined are of variable
length, some information is lost by simple concatenation. For example, length, some information is lost by simple concatenation. For example,
X = "12" and Y = "345" would not be distinguished from X = "123" and Y X = "12" and Y = "345" would not be distinguished from X = "123" and Y
= "45". To preserve that information, each component should be = "45". To preserve that information, each component should be
preceded by an encoding of its length, or end with some sequence that preceded by an encoding of its length or should end with some sequence that
cannot occur within the component, or some similar technique should be cannot occur within the component, or some similar technique should be
used.</t> used.</t>
<t>For FNV, the same hash results if X, Y, and Z are actually <t>For FNV, the same hash results if 1)&nbsp;X, Y, and Z are actually
concatenated and the FNV hash applied to the resulting string or if concatenated and the FNV hash is applied to the resulting string or
FNV is calculated on an initial substring and the result used as the 2)&nbsp;FNV is calculated on an initial substring and the result is used as the
offset_basis when calculating the FNV hash of the remainder of the offset_basis when calculating the FNV hash of the remainder of the
string. This can be done several times. Assuming FNVoffset_basis ( v, string. This can be done several times. Assuming that FNVoffset_basis ( v,
w ) is FNV of w using v as the offset_basis, then in the example w ) is the FNV of w using v as the offset_basis, then in the example
above, fnvx = FNV ( X ) could be calculated and then fnvxy = above, fnvx = FNV ( X ) could be calculated and then fnvxy =
FNVoffset_basis ( fnvx, Y ), and finally fnvxyz = FNVoffset_basis ( FNVoffset_basis ( fnvx, Y ), and finally fnvxyz = FNVoffset_basis (
fnvxy, Z). The resulting fnvxyz would be the same as FNV ( X | Y | Z fnvxy, Z ). The resulting fnvxyz would be the same as FNV ( X | Y | Z&nbsp;).</t
).</t> >
<t>This means that if you have the value of FNV ( X ) and you want to <t>This means that if you have the value of FNV ( X ) and you want to
calculate FNV ( X | Y ), you do not need to find X. You can simply calculate FNV ( X | Y ), you do not need to find X. You can simply
calculate FNVoffset_basis ( FNV ( X ), Y ) and thereby get FNV ( X |Y calculate FNVoffset_basis ( FNV ( X ), Y ) and thereby get FNV ( X | Y&nbsp;).</
).</t> t>
<t>Sometimes such a hash needs to be repeatedly calculated and the <t>Sometimes, such a hash needs to be repeatedly calculated; the
component values vary but some vary more frequently than others. For component values vary, but some vary more frequently than others. For
example, assume some sort of computer network traffic flow ID, such as example, assume that some sort of computer network traffic flow ID, such as
the IPv6 flow ID <xref target="RFC6437"/>, is to be calculated for the IPv6 Flow Label <xref target="RFC6437"/>, is to be calculated for
network packets based on the source and destination IPv6 address and network packets based on the source and destination IPv6 addresses and
the Traffic Class <xref target="RFC8200"/>. If the Flow ID is the Traffic Class <xref target="RFC8200"/>. If the Flow Label is
calculated in the originating host, the source IPv6 address would calculated in the originating host, the source IPv6 address would
likely always be the same or perhaps assume one of a very small number likely always be the same or would perhaps assume one of a very small number
of values. By placing this quasi-constant IPv6 source address first in of values. By placing this quasi-constant IPv6 source address first in
the string being FNV hashed, FNV ( IPv6source ) could be calculated the string being FNV-hashed, FNV ( IPv6source ) could be calculated
and used as the offset_basis for calculating FNV of the IPv6 and used as the offset_basis for calculating the FNV of the IPv6
destination address and Traffic Class for each packet. As a result, destination address and Traffic Class for each packet. As a result,
the per packet hash would be over 17 bytes rather than over 33 bytes the per-packet hash would be over 17 bytes rather than over 33 bytes,
saving computational resources. The source code in this document saving computational resources. The source code in this document
includes functions facilitating the use of a non-standard includes functions facilitating the use of a non-standard
offset_basis.</t> offset_basis.</t>
<t>An alternative method of hashing multiple values is to concatenate <t>An alternative method of hashing multiple values is to concatenate
the hashes of those values and then hash the concatenation, this is, the hashes of those values and then hash the concatenation -- that is,
compute something like</t> compute something like</t>
<artwork align="center"> <artwork align="left"><![CDATA[ hash ( hash (X) | hash (Y) | has
hash ( hash(X) | hash (Y) | hash (Z) ) h (Z) )
</artwork> ]]></artwork>
<t>This will involve more computation than simply computing the hash <t>This will involve more computation than simply computing the hash
of the concatenation of the values and thus, unless parallel of the concatenation of the values and thus, unless parallel
computational resources are available, greater latency; however, if computational resources are available, greater latency; however, if
parallel computational resources are available and the values being parallel computational resources are available and the values being
hashed together are long enough to overcome any initial/final hash hashed together are long enough to overcome any initial/final hash
function overhead, which is very small for FNV, latency can be reduced function overhead, which is very small for FNV, latency can be reduced
by hashing the concatenation of the hashes of the values.</t> by hashing the concatenation of the hashes of the values.</t>
<t>For another example of a similar technique, assume a desire to use <t>For another example of a similar technique, assume a desire to use
FNV-N to hash a byte string of length L. Let B = N/8, the number of FNV-N to hash a byte string of length L. Let B = N/8, the number of
bytes of FNV-N output. If that string is divided into k successive bytes of FNV-N output. If that string is divided into k successive
equal length substrings and assuming, for simplicity, that L is an substrings of equal length and assuming, for simplicity, that L is an
integer multiple of k, hashing the substrings and then hashing the integer multiple of k, hashing the substrings and then hashing the
concatenation of their hashes will hash a total of L + k*B bytes, concatenation of their hashes will hash a total of L + k*B bytes,
clearly more than the initial string size L. However, if sufficient clearly more than the initial string size L. However, if sufficient
parallel computational resources are available to hash all the parallel computational resources are available to hash all the
substrings simultaneously, the elapsed time can be changed substrings simultaneously, the elapsed time can be changed
approximately from on the order of L to on the order of L/k + k*B. For approximately from on the order of L to on the order of L/k + k*B. For
sufficiently large L, this parallelization will reduce the elapsed sufficiently large L, this parallelization will reduce the elapsed
time to produce the overall hash.</t> time to produce the overall hash.</t>
</section> <!-- 4. --> </section>
<section anchor="const"> <!-- 5. --> <section anchor="const">
<name>FNV Constants</name> <name>FNV Constants</name>
<t>The FNV Primes are as follows:</t> <t>The FNV Primes are as follows:</t>
<table> <table>
<thead> <thead>
<tr><th>Size FNV Prime = Expression</th></tr> <tr><th>Size FNV Prime = Expression</th></tr>
<tr><th align="right">= Decimal</th></tr> <tr><th align="right">= Decimal</th></tr>
<tr><th align="right">= Hexadecimal</th></tr> <tr><th align="right">= Hexadecimal</th></tr>
</thead> </thead>
<tbody> <tbody>
<tr><td>32-bit FNV_Prime = 2**24 + 2**8 + 0x93</td></tr> <tr><td>32-bit FNV_Prime = 2**24 + 2**8 + 0x93</td></tr>
<tr><td align="right">= 16,&zwsp;777,&zwsp;619</td></tr> <tr><td align="right">= 16,&zwsp;777,&zwsp;619</td></tr>
skipping to change at line 696 skipping to change at line 655
32E56D5A591028B7 4B29FC4223FDADA1 6C3BF34EDA3674DA 9A21D90000000000 32E56D5A591028B7 4B29FC4223FDADA1 6C3BF34EDA3674DA 9A21D90000000000
0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000
0000000000000000 000000000004C6D7 EB6E73802734510A 555F256CC005AE55 0000000000000000 000000000004C6D7 EB6E73802734510A 555F256CC005AE55
6BDE8CC9C6A93B21 AFF4B16C71EE90B3</td></tr> 6BDE8CC9C6A93B21 AFF4B16C71EE90B3</td></tr>
</tbody> </tbody>
</table> </table>
</section> </section>
<section> <!-- 6. --> <section anchor="sec-cons">
<name>Security Considerations</name> <name>Security Considerations</name>
<t>No assertion of suitability for cryptographic applications is made <t>No assertion of suitability for cryptographic applications is made
for the FNV hash algorithms.</t> for the FNV hash algorithms.</t>
<t>Use of a cryptographic hash function should be considered when <t>The use of a cryptographic hash function should be considered when
active adversaries are a factor (see <xref active adversaries are a factor (see <xref
target="applicability"/>).</t> target="applicability"/>).</t>
<section anchor="bang"> <section anchor="bang">
<name>Inducing Collisions</name> <name>Inducing Collisions</name>
<t>An attacker could attempt to induce collisions to cause denial or <t>An attacker could attempt to induce collisions to cause denial or
degradation of service. Consider the following simplified example: a degradation of service. Consider the following simplified example: A
hash table of n buckets is being maintained with the bucket used by hash table of n buckets is being maintained with the bucket used by
some item i determined by</t> some item i determined by</t>
<artwork align="center"> <artwork align="left"><![CDATA[ hash(i) mod n
hash(i) mod n ]]></artwork>
</artwork>
<t>and with a linked list out of each bucket of the items that all <t>and with a linked list out of each bucket of the items that all
hash to that bucket. Such an arrangement might be used for the symbol hash to that bucket. Such an arrangement might be used for the symbol
table in a compiler or for some of the routing information (i.e., RIB table in a compiler or for some of the routing information (i.e., a RIB
(Routing Information Base)) in a router. Then a large number of items (Routing Information Base)) in a router. A large number of items
hashing to the same bucket will likely result in much slower times to hashing to the same bucket will then likely result in much slower times to
retrieve from or update the information stored through the table for retrieve from or update the information stored through the table for
one of those items. Typically, an attacker could arrange for the one of those items. Typically, an attacker could arrange for the
number of distinct items being hashed to be orders of magnitude larger number of distinct items being hashed to be orders of magnitude larger
than n, even if n was tens or hundreds of thousands, so collisions are than n, even if n was tens or hundreds of thousands, so collisions are
guaranteed to occur in this example regardless of the nature of the guaranteed to occur in this example regardless of the nature of the
hash function.</t> hash function.</t>
<t>There are a number of different circumstances that might surround <t>There are a number of different circumstances that might surround
this example of which the following three are illustrative:</t> this example, of which the following three are illustrative:</t>
<ul> <ul>
<li>If a hash function is being used in an exactly known way for the <li>If a hash function is being used in an exactly known way for the
above scenario, including a known offset_basis such as a standard above scenario, including a known offset_basis such as a standard
offset_basis specified in this document, then an adversary could offset_basis specified in this document, then an adversary could
test items off-line and generate an arbitrary set of items whose test items offline and generate an arbitrary set of items whose
hash table indexes would collide. Under these circumstances, the hash table indexes would collide. Under these circumstances, the
adversary would not have to conduct any trials of actually adversary would not have to conduct any trials of actually
submitting items and would not have to measure performance to find submitting items and would not have to measure performance to find
collisions. Then submitting such a set of items would degrade or collisions. Submitting such a set of items would then degrade or
deny service. For FNV, use of an offset_basis not known by the deny service. For FNV, the use of an offset_basis not known by the
adversary is adequate to defeat this case.</li> adversary is adequate to defeat this case.</li>
<li>If the adversary cannot detect when collisions occur, or service <li>If the adversary cannot detect when collisions occur or when service
is degraded, then it is sufficient for the adversary to be unable to is degraded, then it is sufficient for the adversary to be unable to
predict the hash outcomes. For FNV, use of an offset_basis not known predict the hash outcomes. For FNV, the use of an offset_basis not known
by the adversary may be adequate to defend against this case.</li> by the adversary may be adequate to defend against this case.</li>
<li>If the adversary can detect the degradation in service caused by <li>If the adversary can detect the degradation in service caused by
collisions in the above example and can feed large numbers of collisions in the above example and can feed large numbers of
variable items to the process, then they can collect sets of items variable items to the process, then they can collect sets of items
that appear to collide. Even if there are limits to the number of that appear to collide. Even if there are limits to the number of
items that can be submitted, if there can be multiple trials, the items that can be submitted, if there can be multiple trials, the
adversary can collect multiple sets of items that collide within adversary can collect multiple sets of items that collide within
each set or one growing set of items all of which collide. Then, by each set or one growing set of items, all of which collide. Then, by
submitting such items, the adversary can degrade or deny submitting such items, the adversary can degrade or deny
service. That is true regardless of whether the hash function used service. That is true regardless of whether the hash function used
is a non-cryptographic hash function such as FNV or a cryptographic is a non-cryptographic hash function such as FNV or a cryptographic
hash function such as those in <xref target="FIPS202"/> or <xref hash function such as those specified in <xref target="FIPS202"/> or <xref
target="RFC6234"/>. One defense in this case is to detect when a target="RFC6234"/>. One defense in this case is to detect when a
large number of collisions are happening (which could, but would be large number of collisions are happening (which could, but would be
unlikely to, occur by chance) and, when that is detected, rehash the unlikely to, occur by chance) and, when that is detected, rehash the
items with some change to the hash algorithm and use the changed items with some change to the hash algorithm and use the changed
hash algorithm for subsequent items; for example, if FNV is being hash algorithm for subsequent items -- for example, if FNV is being
used, to rehash with a different offset_basis and then continue used, to rehash with a different offset_basis and then continue
using that new offset_basis. There exist commercially deployed using that new offset_basis. There exist commercially deployed
routers that use this technique to ameliorate excessive hash routers that use this technique to ameliorate excessive hash
collisions in internal tables.</li> collisions in internal tables.</li>
</ul> </ul>
</section> </section>
</section> <!-- 6. --> </section>
<section> <!-- 7. --> <section>
<name>Historical Notes</name> <name>Historical Notes</name>
<t>The FNV hash algorithm originated from an idea submitted as <t>The FNV hash algorithm originated from an idea submitted as
reviewer comments to the <xref target="IEEE"/> POSIX P1003.2 reviewer comments to the IEEE POSIX P1003.2 committee <xref target="IEEE"/> in
committee in 1991 by Glenn Fowler and Phong Vo. Subsequently, during 1991 by <contact fullname="Glenn Fowler"/> and <contact fullname="Phong Vo"/>.
a ballot round, Landon Curt Noll proposed an enhancement to their Subsequently, during
a ballot round, <contact fullname="Landon Curt Noll"/> proposed an enhancement
to their
algorithm. Some people tried this hash and found that it worked algorithm. Some people tried this hash and found that it worked
rather well. In an EMail message to Landon, they named it the rather well. In an email message to Landon, they named it the
"Fowler/Noll/Vo" or FNV hash from their last names in alphabetic "Fowler/Noll/Vo" or FNV hash from their last names in alphabetical
order. <xref target="FNV"/></t> order <xref target="FNV"/>.
</t>
<!-- LB: Checked the quoted (DNE) text below, and fixed it to match
what's listed in the reference. -->
<t>The string used to calculate the offset_basis values (see <xref <t>The string used to calculate the offset_basis values (see <xref
target="constoffb"/>) was selected because the person testing FNV target="constoffb"/>) was selected because the person testing FNV
with non-zero offset_basis values was looking at an email message with non-zero offset_basis values was looking at an email message
from Landon and was copying his standard email signature line; from Landon and was copying his standard email signature line;
however, they "didn't see very well" <xref target="FNV"/> and copied however, they "did not see very well" <xref target="FNV"/> and copied
it incorrectly. In fact, Landon uses</t> it incorrectly. In fact, Landon uses</t>
<artwork align="center" type="ascii-art"> <artwork align="left"><![CDATA[ chongo (Landon Curt Noll)
chongo (Landon Curt Noll) /\oo/\ /\oo/\
</artwork> ]]></artwork>
<t>but, since it doesn't matter, no effort has been made to correct <t>but, since it doesn't matter, no effort has been made to correct
this.</t> this.</t>
</section> <!-- 7. --> </section>
<section anchor="SourceCode"> <!-- 8. --> <section anchor="SourceCode">
<name>The Source Code</name> <name>The Source Code</name>
<t>The following sub-sections provide reference <xref target="C"/> <t>The following subsections provide reference C source code <xref target="C"/>
source code and a test driver with command line interface for and a test driver with a command line interface for
FNV-1a.</t> FNV-1a.</t>
<t>Section 8.2 provides the C header and code source files for the FNV <t><xref target="sec-8.2"/> provides the C header and code source files for the
functions. Section 8.3 provides the test driver. Section 8.4 provides FNV
functions. <xref target="sec-8.3"/> provides the test driver. <xref target="sec-
8.4"/> provides
a simple makefile to build the test driver or a library file with all a simple makefile to build the test driver or a library file with all
FNV sizes.</t> FNV sizes.</t>
<t>Alternative source code for 32- and 64-bit FNV is available at <t>Alternative source code for 32- and 64-bit FNV is available at
<xref target="LCN2"/>. Other alternative source code, including in x86 <xref target="LCN2"/>. Other alternative source code, including in x86
assembler, is currently available at <xref target="FNV"/>. In some assembler, is currently available at <xref target="FNV"/>. In some
cases, this further source code has been further optimized.</t> cases, this further source code has been further optimized.</t>
<section> <!-- 8.1 --> <section>
<name>Source Code Details</name> <name>Source Code Details</name>
<section> <!-- 8.1.1 --> <section>
<name>FNV Functions Available</name> <name>FNV Functions Available</name>
<t>The functions provided are listed below. The "xxx" in the <t>The functions provided are listed below. The "xxx" in the
function names is "32", "64", "128", "256", "512", or "1024" function names is "32", "64", "128", "256", "512", or "1024",
depending on the length of the FNV. All of the FNV hash functions depending on the length of the FNV. All of the FNV hash functions
have as their return value an integer whose meaning is specified in have as their return value an integer whose meaning is specified in
FNVErrorCodes.h.</t> FNVErrorCodes.h.</t>
<t>Functions providing a byte vector hash are available for all <t>Functions providing a byte vector hash are available for all
lengths. For FNV-32, versions are available that provide a 32-bit lengths. For FNV-32, versions are available that provide a 32-bit
integer and are identified by replacing "xxx" with "32INT". For integer and are identified by replacing "xxx" with "32INT". For
example, FNV32string provides a 4-byte vector but FNV32INTstring example, FNV32string provides a 4-byte vector, but FNV32INTstring
provides a 32-bit integer. For FNV-64, if compiled with 64-bit provides a 32-bit integer. For FNV-64, if compiled with 64-bit
integers enabled (i.e., FNV_64bitIntegers defined, see FNVconfig.h), integers enabled (i.e., FNV_64bitIntegers defined; see FNVconfig.h),
versions are available that provide a 64-bit integer and are versions are available that provide a 64-bit integer and are
identified by replacing "xxx" with "64INT"`. Versions providing an identified by replacing "xxx" with "64INT". Versions providing an
integer hash will not be compatible between systems of different integer hash will not be compatible between systems of different
endian-ness (see <xref target="endian"/>).</t> endianness (see <xref target="endian"/>).</t>
<t>If you want to copy the source code from this document, note that <t>If you want to copy the source code from this document, note that
it is indented by three spaces in the ".txt" version. It may be it is indented by three spaces in the ".txt" version. It may be
simplest to copy from the ".html" version of this document.</t> simplest to copy from the ".html" version of this document.</t>
<dl> <dl>
<dt>FNVxxxstring, FNVxxxblock, FNVxxxfile:</dt><dd/> <dt>FNVxxxstring, FNVxxxblock, FNVxxxfile:</dt><dd/>
<dt>FNVxxxstringBase, FNVxxxblockBase, FNVxxxfileBase:</dt><dd/> <dt>FNVxxxstringBasis, FNVxxxblockBasis, FNVxxxfileBasis:</dt><dd/>
<dt>FNVxxxINTstring, FNVxxxINTblock, FNVxxxINTfile:</dt><dd/> <dt>FNVxxxINTstring, FNVxxxINTblock, FNVxxxINTfile:</dt><dd/>
<dt>FNVxxxINTstringBase, FNVxxxINTblockBase,
FNVxxxINTfileBase:</dt> <dt>FNVxxxINTstringBasis, FNVxxxINTblockBasis,
FNVxxxINTfileBasis:</dt>
<dd>These are simple functions for directly returning the FNV hash <dd>These are simple functions for directly returning the FNV hash
of a zero terminated byte string not including that zero byte, the of a zero-terminated byte string not including that zero byte, the
FNV hash of a counted block of bytes, and the FNV of a file, FNV hash of a counted block of bytes, and the FNV of a file,
respectively. The functions whose name has the "Base" suffix take respectively. The functions whose names have the "Basis" suffix take
an additional parameter specifying the offset_basis. Note that for an additional parameter specifying the offset_basis. Note that for
applications of FNV-32 and of FNV-64 where integers of that size applications of FNV-32 and of FNV-64 where integers of that size
are supported and an integer data type output is acceptable, the are supported and an integer data type output is acceptable, the
code is sufficiently simple that, to maximize performance, use of code is sufficiently simple that, to maximize performance, the use of
open coding or macros may be more appropriate than calling a open coding or macros may be more appropriate than calling a
subroutine.</dd> subroutine.</dd>
<dt>FNVxxxinit, FNVxxxinitBasis:</dt><dd/> <dt>FNVxxxinit, FNVxxxinitBasis:</dt><dd/>
<dt>FNVxxxINTinitBasis:</dt><dd>These functions and the next two <dt>FNVxxxINTinitBasis:</dt><dd>These functions and the next two
sets of functions below provide facilities for incrementally sets of functions below provide facilities for incrementally
calculating FNV hashes. They all assume a data structure of type calculating FNV hashes. They all assume a data structure of type
FNVxxxcontext that holds the current state of the hash. FNVxxxinit FNVxxxcontext that holds the current state of the hash. FNVxxxinit
initializes that context to the standard initializes that context to the standard
offset_basis. FNVxxxinitBasis takes an offset_basis value as a offset_basis. FNVxxxinitBasis takes an offset_basis value as a
parameter and may be useful for hashing concatenations, as parameter and may be useful for hashing concatenations, as
described in Section 4, as well as for simply using a non-standard described in <xref target="sec-4"/>, as well as for simply using a non-stand ard
offset_basis.</dd> offset_basis.</dd>
<dt>FNVxxxblockin, FNVxxxstringin, FNVxxxfilein:</dt><dd>These <dt>FNVxxxblockin, FNVxxxstringin, FNVxxxfilein:</dt><dd>These
functions hash a sequence of bytes into an FNVxxxcontext that was functions hash a sequence of bytes into an FNVxxxcontext that was
originally initialized by FNVxxxinit or originally initialized by FNVxxxinit or
FNVxxxinitBasis. FNVxxxblockin hashes in a counted block of FNVxxxinitBasis. FNVxxxblockin hashes in a counted block of
bytes. FNVxxxstringin hashes in a zero terminated byte string not bytes. FNVxxxstringin hashes in a zero-terminated byte string not
including the final zero byte. FNVxxxfilein hashes in the contents including the final zero byte. FNVxxxfilein hashes in the contents
of a file.</dd> of a file.</dd>
<dt>FNVxxxresult, FNVxxxINTresult:</dt><dd>This function extracts <dt>FNVxxxresult, FNVxxxINTresult:</dt><dd>This function extracts
the final FNV hash result from an FNVxxxcontext.</dd> the final FNV hash result from an FNVxxxcontext.</dd>
</dl> </dl>
</section> </section>
<section> <!-- 8.1.2 --> <section>
<name>Source Files and 64-bit Support </name> <name>Source Files and 64-Bit Support </name>
<t>Code optimized for 64-bit integer support, that is, support of <t>Code optimized for 64-bit integer support -- that is, support of
64-bit integer addition and 32x32-bit multiplication producing a 64-bit integer addition and 32-bit x 32-bit multiplication producing a
64-bit product, is provided based on whether or not the 64-bit product -- is provided based on whether or not the
FNV_64bitIntegers symbol is defined. By default, this is set in FNV_64bitIntegers symbol is defined. By default, this is set in
FNVconfig.h based on the compilation target; however, this can be FNVconfig.h based on the compilation target; however, this can be
overridden by editing that file or by defining certain symbols in, for overridden by editing that file or by defining certain symbols in, for
example, a command line invoking compilation.</t> example, a command line invoking a compilation.</t>
<t>For support of a single FNV size, say "xxx", in an application, the <t>For support of a single FNV size, say "xxx" (e.g., FNV64), in an application,
application itself needs to include the FNVxxx.h (which will, in turn, the
include the FNVconfig.h and FNVErrorCodes.h) files. To build the application itself needs to include the appropriate FNVxxx.h file (which will, i
n turn,
include the FNVconfig.h and FNVErrorCodes.h files). To build the
particular FNVxxx code itself, compile the FNVxxx.c file with particular FNVxxx code itself, compile the FNVxxx.c file with
FNVconfig.h, fnv-private.h, FNVErrorCodes.h, and FNVxxx.h FNVconfig.h, fnv-private.h, FNVErrorCodes.h, and FNVxxx.h (available to the comp
available. Since the test program in Section 8.3 uses all sizes of iler while compiling the FNVxxx.c file; see <xref target="sec-8.2"/>). Since the
FNV, all the .c and .h files are needed to compile it.</t> test program provided in <xref target="sec-8.3"/> uses all sizes of FNV, all th
e .c and .h files are needed to compile it.</t>
</section> </section>
<section> <!-- 8.1.3 --> <section anchor="sec-8.1.3">
<name>Command Line Interface</name> <name>Command Line Interface</name>
<t>The test program provided in Section 8.3 has a command line <t>The test program provided in <xref target="sec-8.3"/> has a command line
interface. By default, with no command line arguments, it runs interface. By default, with no command line arguments, it runs
tests of all FNV lengths. Command line options are as follows:</t> tests of all FNV lengths. Command line options are as follows:</t>
<artwork align="center" type="ascii-art"> <artwork align="left"><![CDATA[ FNVhash [-a] [-h] [-t nnn] [-u nnn] [-v] [-f f
FNVhash [-a] [-h] [-t nnn] [-u nnn] [-v] [-f filename] [token ...] ilename] [token ...]
</artwork> ]]></artwork>
<t>The option letters have the following meaning:</t> <t>The option letters have the following meanings:</t>
<dl> <dl newline="false">
<dt>-a</dt><dd>Run tests for all lengths.</dd> <dt>-a</dt><dd>Run tests for all lengths.</dd>
<dt>-h</dt><dd>Print a help message about the command line.</dd> <dt>-h</dt><dd>Print a help message about the command line.</dd>
<dt>-v</dt><dd>Complement the Verbose flag which is initially <dt>-v</dt><dd>Complement the Verbose flag, which is initially
off. When the flag is on, the program prints more information during off. When the flag is on, the program prints more information during
tests, etc.</dd> tests, etc.</dd>
<dt>-t nnn</dt><dd>Run tests for length nnn which must be one of 32, <dt>-t nnn</dt><dd>Run tests for length nnn, which must be one of 32,
64, 128, 256, 512, or 1024.</dd> 64, 128, 256, 512, or 1024.</dd>
<dt>-u nnn</dt><dd>Use hash size nnn which must be one of 32, 64, <dt>-u nnn</dt><dd>Use hash size nnn, which must be one of 32, 64,
128, 256, 512, or 1024. This is useful to set the hash size for use 128, 256, 512, or 1024. This is useful for setting the hash size for use
by the -f option or in hashing tokens on the command line after the by the -f option or in hashing tokens on the command line after the
options.</dd> options.</dd>
<dt>-f filename</dt><dd>Hash the contents of the file with name <dt>-f filename</dt><dd>Hash the contents of the file with name
filename. The hash size must have been set by a prior -t or -u filename. The hash size must have been set by a prior -t or -u
option in the command line.</dd> option in the command line.</dd>
<dt>token</dt><dd>Tokens appearing on the command line after the <dt>token</dt><dd>Tokens appearing on the command line after the
options are hashed with the current hash size which must have been options are hashed with the current hash size, which must have been
set by a prior -t or -u option in the command line.</dd> set by a prior -t or -u option in the command line.</dd>
</dl> </dl>
<t>For example,</t> <t>For example,</t>
<artwork align="center" type="ascii-art"> <artwork align="left"><![CDATA[ FNVhash -t 128 -h -v -t 64 -v -u 256 -f foo
FNVhash -t 128 -h -v -t 64 -v -u 256 -f foobar.txt RabOof 1234 bar.txt RabOof 1234
</artwork> ]]></artwork>
<t>runs tests for FNV128, then prints a command line help message, <t>runs tests for FNV128, then prints a command line help message,
then turns on Verbose, then runs the tests for FNV64, then turns off then turns on Verbose, then runs the tests for FNV64, then turns off
Verbose, then sets the hash size to 256, then hashes the contents of Verbose, then sets the hash size to 256, then hashes the contents of
file foobar.txt, then hashes the token "RabOof", and finally hashes file foobar.txt, then hashes the token "RabOof", and finally hashes
the token "1234".</t> the token "1234".</t>
</section> </section>
</section> </section>
<section> <!-- 8.2 --> <section anchor="sec-8.2">
<name>FNV-1a C Code</name> <name>FNV-1a C Code</name>
<t>This section provides the direct FNV-1a function for each of the <t>This section provides the direct FNV-1a function for each of the
lengths for which it is specified in this document.</t> lengths for which it is specified in this document.</t>
<t>The following is a configuration header to set whether 64-bit <t>The following is a configuration header to set whether 64-bit
integers are supported and establish an enum used for return integers are supported and establish an enum used for return
values.</t> values.</t>
<sourcecode type="C" markers="true" name="FNVconfig.h"> <sourcecode type="c" markers="true" name="FNVconfig.h"><![CDATA[
<![CDATA[
//************************ FNVconfig.h **************************// //************************ FNVconfig.h **************************//
//**************** See RFC NNNN for details. ********************// //**************** See RFC 9923 for details. ********************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
*
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#ifndef _FNVconfig_H_ #ifndef _FNVconfig_H_
#define _FNVconfig_H_ #define _FNVconfig_H_
/* Description: /*
* Description:
* This file provides configuration ifdefs for the * This file provides configuration ifdefs for the
* FNV-1a non-cryptographic hash algorithms. */ * FNV-1a non-cryptographic hash algorithms. */
/* FNV_64bitIntegers - Define this if your system supports /* FNV_64bitIntegers - Define this if your system supports
* 64-bit arithmetic including 32-bit x 32-bit * 64-bit arithmetic including 32-bit x 32-bit
* multiplication producing a 64-bit product. If * multiplication producing a 64-bit product. If
* undefined, it will be assumed that 32-bit arithmetic * undefined, it will be assumed that 32-bit arithmetic
* is supported including 16-bit x 16-bit multiplication * is supported including 16-bit x 16-bit multiplication
* producing a 32-bit result. * producing a 32-bit result.
*/ */
#include <stdint.h> #include <stdint.h>
/* Check if 64-bit integers are supported in the target */ /* Check if 64-bit integers are supported in the target */
#ifdef UINT64_MAX #ifdef UINT64_MAX
skipping to change at line 1035 skipping to change at line 991
# define uint64_t no_64_bit_integers # define uint64_t no_64_bit_integers
# endif # endif
#endif #endif
#endif /* _FNVconfig_H_ */ #endif /* _FNVconfig_H_ */
]]></sourcecode> ]]></sourcecode>
<t>The following code is a simple header file to define the return <t>The following code is a simple header file to define the return
value error codes for the FNV routines.</t> value error codes for the FNV routines.</t>
<sourcecode type="C" markers="true" name="FNVErrorCodes.h"> <sourcecode type="c" markers="true" name="FNVErrorCodes.h"><![CDATA[
//********************** FNVErrorCodes.h **************************// //********************** FNVErrorCodes.h **************************//
//**************** See RFC NNNN for details. **********************// //**************** See RFC 9923 for details. **********************//
/* Copyright (c) 2016, 2023, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#ifndef _FNV_ErrCodes_ #ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_ #define _FNV_ErrCodes_
//****************************************************************// //****************************************************************//
// //
// All FNV functions, except the FNVxxxfile functions, // All FNV functions, except the FNVxxxfile functions,
// return an integer as follows: // return an integer as follows:
// 0 -> success // 0 -> success
// >0 -> error as listed below // >0 -> error as listed below
// //
enum { /* success and errors */ enum { /* success and errors */
fnvSuccess = 0, fnvSuccess = 0,
fnvNull, // 1 Null pointer parameter fnvNull, // 1 Null pointer parameter
fnvStateError, // 2 called Input after Result or before Init fnvStateError, // 2 called Input after Result or before Init
fnvBadParam // 3 passed a bad parameter fnvBadParam // 3 passed a bad parameter
}; };
#endif /* _FNV_ErrCodes_ */ #endif /* _FNV_ErrCodes_ */
</sourcecode> ]]></sourcecode>
<t>The following code is a private header file used by all the FNV <t>The following code is a private header file that is used by all the FNV
functions further below and which states the terms for use and functions further below and that states the terms for use and
redistribution of all of this source code.</t> redistribution of all of this source code.</t>
<sourcecode type="C" markers="true" name="fnv-private.h"> <sourcecode type="c" markers="true" name="fnv-private.h"><![CDATA[
//********************** fnv-private.h ************************// //************************ fnv-private.h **************************//
//**************** See RFC NNNN for details *******************// //****************** See RFC 9923 for details. ********************//
/* Copyright (c) 2016, 2023, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* *
* Redistribution and use in source and binary forms, with or without * Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions * modification, are permitted provided that the following conditions
* are met: * are met:
* *
* * Redistributions of source code must retain the above copyright * * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer. * notice, this list of conditions and the following disclaimer.
* *
* * Redistributions in binary form must reproduce the above * * Redistributions in binary form must reproduce the above
skipping to change at line 1092 skipping to change at line 1048
* *
* * Neither the name of Internet Society, IETF or IETF Trust, nor * * Neither the name of Internet Society, IETF or IETF Trust, nor
* the names of specific contributors, may be used to endorse or * the names of specific contributors, may be used to endorse or
* promote products derived from this software without specific * promote products derived from this software without specific
* prior written permission. * prior written permission.
* *
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE. * SUCH DAMAGE.
*/ */
skipping to change at line 1117 skipping to change at line 1073
* Six FNV-1a hashes are defined with these sizes: * Six FNV-1a hashes are defined with these sizes:
* FNV32 32 bits, 4 bytes * FNV32 32 bits, 4 bytes
* FNV64 64 bits, 8 bytes * FNV64 64 bits, 8 bytes
* FNV128 128 bits, 16 bytes * FNV128 128 bits, 16 bytes
* FNV256 256 bits, 32 bytes * FNV256 256 bits, 32 bytes
* FNV512 512 bits, 64 bytes * FNV512 512 bits, 64 bytes
* FNV1024 1024 bits, 128 bytes * FNV1024 1024 bits, 128 bytes
*/ */
/* Private stuff used by this implementation of the FNV /* Private stuff used by this implementation of the FNV
* (Fowler, Noll, Vo) non-cryptographic hash function FNV-1a. * (Fowler/Noll/Vo) non-cryptographic hash function FNV-1a.
* External callers don't need to know any of this. */ * External callers don't need to know any of this. */
enum { /* State value bases for context->Computed */ enum { /* State value bases for context->Computed */
FNVinited = 22, FNVinited = 22,
FNVcomputed = 76, FNVcomputed = 76,
FNVemptied = 220, FNVemptied = 220,
FNVclobber = 122 /* known bad value for testing */ FNVclobber = 122 /* known bad value for testing */
}; };
/* Deltas to assure distinct state values for different lengths */ /* Deltas to assure distinct state values for different lengths */
enum { enum {
FNV32state = 1, FNV32state = 1,
FNV64state = 3, FNV64state = 3,
FNV128state = 5, FNV128state = 5,
FNV256state = 7, FNV256state = 7,
FNV512state = 11, FNV512state = 11,
FNV1024state = 13 FNV1024state = 13
}; };
#endif /* _FNV_PRIVATE_H_ */ #endif /* _FNV_PRIVATE_H_ */
</sourcecode> ]]></sourcecode>
<section> <section>
<name>FNV32 Code</name> <name>FNV32 Code</name>
<t>The header and C source for 32-bit FNV-1a providing a 32-bit <t>The following code is the header and C source for 32-bit FNV-1a providing a 3 2-bit
integer or 4-byte vector hash.</t> integer or 4-byte vector hash.</t>
<sourcecode type="C" markers="true" name="FNV32.h"> <sourcecode type="c" markers="true" name="FNV32.h"><![CDATA[
<![CDATA[
//*************************** FNV32.h ****************************// //*************************** FNV32.h ****************************//
//****************** See RFC NNNN for details ********************// //****************** See RFC 9923 for details. *******************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#ifndef _FNV32_H_ #ifndef _FNV32_H_
#define _FNV32_H_ #define _FNV32_H_
/* /*
* Description: * Description:
* This file provides headers for the 32-bit version of * This file provides headers for the 32-bit version of
skipping to change at line 1175 skipping to change at line 1130
#include "FNVErrorCodes.h" #include "FNVErrorCodes.h"
#include <stdint.h> #include <stdint.h>
#define FNV32size (32/8) #define FNV32size (32/8)
#define FNV32basis 0x811C9DC5 #define FNV32basis 0x811C9DC5
/* If you do not have the ISO standard stdint.h header file, then /* If you do not have the ISO standard stdint.h header file, then
* you must typedef the following types: * you must typedef the following types:
* *
* type meaning * type meaning
* uint32_t unsigned 32-bit integer * uint32_t unsigned 32-bit integer
* uint8_t unsigned 8-bit integer (i.e., unsigned char) * uint8_t unsigned 8-bit integer (i.e., unsigned char)
*/ */
/* /*
* This structure holds context information for an FNV32 hash * This structure holds context information for an FNV32 hash
*/ */
typedef struct FNV32context_s { typedef struct FNV32context_s {
int Computed; /* state */ int Computed; /* state */
uint32_t Hash; uint32_t Hash;
} FNV32context; } FNV32context;
/* /* Function Prototypes:
* Function Prototypes:
* *
* FNV32string: hash a zero-terminated string not including * FNV32string: hash a zero-terminated string not including
* the terminating zero * the terminating zero
* FNV32stringBasis: also takes an offset_basis parameter * FNV32stringBasis: also takes an offset_basis parameter
* *
* FNV32block: hash a specified length byte vector * FNV32block: hash a byte vector of a specified length
* FNV32blockBasis: also takes an offset_basis parameter * FNV32blockBasis: also takes an offset_basis parameter
* *
* FNV32file: hash the contents of a file * FNV32file: hash the contents of a file
* FNV32fileBasis: also takes an offset_basis parameter * FNV32fileBasis: also takes an offset_basis parameter
* *
* FNV32init: initializes an FNV32 context * FNV32init: initializes an FNV32 context
* FNV32initBasis: initializes an FNV32 context with a * FNV32initBasis: initializes an FNV32 context with a
* provided 4-byte vector basis * provided 4-byte vector basis
* FNV32blockin: hash in a specified length byte vector * FNV32blockin: hash in a byte vector of a specified length
* FNV32stringin: hash in a zero-terminated string not * FNV32stringin: hash in a zero-terminated string not
* including the terminating zero * including the terminating zero
* FNV32filein: hash in the contents of a file * FNV32filein: hash in the contents of a file
* FNV32result: returns the hash value * FNV32result: returns the hash value
* *
* Hash is returned as a 4-byte vector by the functions above, * Hash is returned as a 4-byte vector by the functions above,
* and the following return a 32-bit unsigned integer: * and the following return a 32-bit unsigned integer:
* *
* FNV32INTstring: hash a zero-terminated string not including * FNV32INTstring: hash a zero-terminated string not including
* the terminating zero * the terminating zero
* FNV32INTstringBasis: also takes an offset_basis parameter * FNV32INTstringBasis: also takes an offset_basis parameter
* *
* FNV32INTblock: hash a specified length byte vector * FNV32INTblock: hash a byte vector of a specified length
* FNV32INTblockBasis: also takes an offset_basis parameter * FNV32INTblockBasis: also takes an offset_basis parameter
* *
* FNV32INTfile: hash the contents of a file * FNV32INTfile: hash the contents of a file
* FNV32INTfileBasis: also takes an offset_basis parameter * FNV32INTfileBasis: also takes an offset_basis parameter
* *
* FNV32INTinitBasis: initializes an FNV32 context with a * FNV32INTinitBasis: initializes an FNV32 context with a
* provided 32-bit integer basis * provided 32-bit integer basis
* FNV32INTresult: returns the hash value * FNV32INTresult: returns the hash value
*/ */
skipping to change at line 1290 skipping to change at line 1244
extern int FNV32result ( FNV32context * const, extern int FNV32result ( FNV32context * const,
uint8_t out[FNV32size] ); uint8_t out[FNV32size] );
#ifdef __cplusplus #ifdef __cplusplus
} }
#endif #endif
#endif /* _FNV32_H_ */ #endif /* _FNV32_H_ */
]]></sourcecode> ]]></sourcecode>
<sourcecode type="C" markers="true" name="FNV32.c"> <sourcecode type="c" markers="true" name="FNV32.c"><![CDATA[
<![CDATA[
//************************** FNV32.c **************************// //************************** FNV32.c **************************//
//**************** See RFC NNNN for details. ******************// //**************** See RFC 9923 for details. ******************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
/* This code implements the FNV (Fowler, Noll, Vo) non-cryptographic /* This code implements the FNV (Fowler/Noll/Vo) non-cryptographic
* hash function FNV-1a for 32-bit hashes. * hash function FNV-1a for 32-bit hashes.
*/ */
#include <stdio.h> #include <stdio.h>
#include "fnv-private.h" #include "fnv-private.h"
#include "FNV32.h" #include "FNV32.h"
/* 32-bit FNV_prime = 2^24 + 2^8 + 0x93 */ /* 32-bit FNV_prime = 2^24 + 2^8 + 0x93 */
#define FNV32prime 0x01000193 #define FNV32prime 0x01000193
/* FNV32 hash a zero-terminated string not including the zero /* FNV32: hash a zero-terminated string not including the zero
*****************************************************************/ *****************************************************************/
int FNV32INTstring ( const char *in, uint32_t * const out ) { int FNV32INTstring ( const char *in, uint32_t * const out ) {
return FNV32INTstringBasis( in, out, FNV32basis ); return FNV32INTstringBasis ( in, out, FNV32basis );
} /* end FNV32INTstring */ } /* end FNV32INTstring */
/* FNV32 hash a zero-terminated string not including the zero /* FNV32: hash a zero-terminated string not including the zero
* with a non-standard basis * with a non-standard basis
*****************************************************************/ *****************************************************************/
int FNV32INTstringBasis ( const char *in, int FNV32INTstringBasis ( const char *in,
uint32_t * const out, uint32_t * const out,
uint32_t basis ) { uint32_t basis ) {
uint8_t ch; uint8_t ch;
if ( !in || !out ) if ( !in || !out )
return fnvNull; /* Null input pointer */ return fnvNull; /* Null input pointer */
while ( (ch = *in++) ) while ( (ch = *in++) )
basis = FNV32prime * ( basis ^ ch ); basis = FNV32prime * ( basis ^ ch );
*out = basis; *out = basis;
return fnvSuccess; return fnvSuccess;
} /* end FNV32INTstringBasis */ } /* end FNV32INTstringBasis */
/* FNV32 hash a zero-terminated string not including the zero /* FNV32: hash a zero-terminated string not including the zero
*****************************************************************/ *****************************************************************/
int FNV32string ( const char *in, uint8_t out[FNV32size] ) { int FNV32string ( const char *in, uint8_t out[FNV32size] ) {
uint32_t temp; uint32_t temp;
uint8_t ch; uint8_t ch;
if ( !in || !out ) if ( !in || !out )
return fnvNull; /* Null input pointer */ return fnvNull; /* Null input pointer */
temp = FNV32basis; temp = FNV32basis;
while ( (ch = *in++) ) while ( (ch = *in++) )
temp = FNV32prime * ( temp ^ ch ); temp = FNV32prime * ( temp ^ ch );
for ( int i=0; i<FNV32size; ++i ) for ( int i=0; i<FNV32size; ++i )
out[i] = ((uint8_t *)&temp)[i]; out[i] = ((uint8_t *)&temp)[i];
return fnvSuccess; return fnvSuccess;
} /* end FNV32string */ } /* end FNV32string */
/* FNV32 hash a zero-terminated string not including the zero /* FNV32: hash a zero-terminated string not including the zero
* with a non-standard basis * with a non-standard basis
*****************************************************************/ *****************************************************************/
int FNV32stringBasis ( const char *in, int FNV32stringBasis ( const char *in,
uint8_t out[FNV32size], uint8_t out[FNV32size],
const uint8_t basis[FNV32size] ) { const uint8_t basis[FNV32size] ) {
uint32_t temp; uint32_t temp;
int i; int i;
uint8_t ch; uint8_t ch;
if ( !in || !out || !basis ) if ( !in || !out || !basis )
skipping to change at line 1372 skipping to change at line 1325
while ( (ch = *in++) ) while ( (ch = *in++) )
temp = FNV32prime * ( temp ^ ch ); temp = FNV32prime * ( temp ^ ch );
out[0] = temp & 0xFF; out[0] = temp & 0xFF;
for ( i=1; i<FNV32size; ++i ) { for ( i=1; i<FNV32size; ++i ) {
temp >>= 8; temp >>= 8;
out[i] = temp & 0xFF; out[i] = temp & 0xFF;
} }
return fnvSuccess; return fnvSuccess;
} /* end FNV32stringBasis */ } /* end FNV32stringBasis */
/* FNV32 hash a counted block returning an integer /* FNV32: hash a counted block returning an integer
****************************************************************/ ****************************************************************/
int FNV32INTblock ( const void *vin, int FNV32INTblock ( const void *vin,
long int length, long int length,
uint32_t * const out ) { uint32_t * const out ) {
return FNV32INTblockBasis ( vin, length, out, FNV32basis ); return FNV32INTblockBasis ( vin, length, out, FNV32basis );
} /* end FNV32INTblock */ } /* end FNV32INTblock */
/* FNV32 hash a counted block with a non-standard basis /* FNV32: hash a counted block with a non-standard basis
****************************************************************/ ****************************************************************/
int FNV32INTblockBasis ( const void *vin, int FNV32INTblockBasis ( const void *vin,
long int length, long int length,
uint32_t * const out, uint32_t * const out,
uint32_t basis ) { uint32_t basis ) {
const uint8_t *in = (const uint8_t*)vin; const uint8_t *in = (const uint8_t*)vin;
uint32_t temp; uint32_t temp;
if ( !in || !out ) if ( !in || !out )
return fnvNull; /* Null input pointer */ return fnvNull; /* Null input pointer */
if ( length < 0 ) if ( length < 0 )
return fnvBadParam; return fnvBadParam;
for ( temp = basis; length > 0; length-- ) for ( temp = basis; length > 0; length-- )
temp = FNV32prime * ( temp ^ *in++ ); temp = FNV32prime * ( temp ^ *in++ );
*out = temp; *out = temp;
return fnvSuccess; return fnvSuccess;
} /* end FNV32INTblockBasis */ } /* end FNV32INTblockBasis */
/* FNV32 hash a counted block returning a 4-byte vector /* FNV32: hash a counted block returning a 4-byte vector
****************************************************************/ ****************************************************************/
int FNV32block ( const void *vin, int FNV32block ( const void *vin,
long int length, long int length,
uint8_t out[FNV32size] ) { uint8_t out[FNV32size] ) {
const uint8_t *in = (const uint8_t*)vin; const uint8_t *in = (const uint8_t*)vin;
uint32_t temp; uint32_t temp;
if ( !in || !out ) if ( !in || !out )
return fnvNull; /* Null input pointer */ return fnvNull; /* Null input pointer */
if ( length < 0 ) if ( length < 0 )
return fnvBadParam; return fnvBadParam;
for ( temp = FNV32basis; length > 0; length-- ) for ( temp = FNV32basis; length > 0; length-- )
temp = FNV32prime * ( temp ^ *in++ ); temp = FNV32prime * ( temp ^ *in++ );
for ( int i=0; i<FNV32size; ++i ) for ( int i=0; i<FNV32size; ++i )
out[i] = ((uint8_t *)&temp)[i]; out[i] = ((uint8_t *)&temp)[i];
return fnvSuccess; return fnvSuccess;
} /* end FNV32block */ } /* end FNV32block */
/* FNV32 hash a counted block with a non-standard basis /* FNV32: hash a counted block with a non-standard basis
****************************************************************/ ****************************************************************/
int FNV32blockBasis ( const void *vin, int FNV32blockBasis ( const void *vin,
long int length, long int length,
uint8_t out[FNV32size], uint8_t out[FNV32size],
const uint8_t basis[FNV32size] ) { const uint8_t basis[FNV32size] ) {
const uint8_t *in = (const uint8_t*)vin; const uint8_t *in = (const uint8_t*)vin;
uint32_t temp; uint32_t temp;
if ( !in || !out || !basis ) if ( !in || !out || !basis )
return fnvNull; /* Null input pointer */ return fnvNull; /* Null input pointer */
skipping to change at line 1649 skipping to change at line 1602
return fnvNull; return fnvNull;
if ( ctx->Computed != FNVcomputed+FNV32state ) if ( ctx->Computed != FNVcomputed+FNV32state )
return fnvStateError; return fnvStateError;
ctx->Computed = FNVemptied+FNV32state; ctx->Computed = FNVemptied+FNV32state;
for ( int i=0; i<FNV32size; ++i ) for ( int i=0; i<FNV32size; ++i )
out[i] = ((uint8_t *)&ctx->Hash)[i]; out[i] = ((uint8_t *)&ctx->Hash)[i];
ctx->Hash = 0; ctx->Hash = 0;
return fnvSuccess; return fnvSuccess;
} /* end FNV32result */ } /* end FNV32result */
]]></sourcecode> ]]></sourcecode>
</section> </section>
<section> <section>
<name>FNV64 Code</name> <name>FNV64 Code</name>
<t>The header and C source for 64-bit FNV-1a. Provides an 8-byte <t>The following code is the header and C source for 64-bit FNV-1a providing an 8-byte
vector or, optionally, if 64-bit integers are supported, a 64-bit vector or, optionally, if 64-bit integers are supported, a 64-bit
integer hash.</t> integer hash.</t>
<sourcecode type="C" markers="true" name="FNV64.h"> <sourcecode type="c" markers="true" name="FNV64.h"><![CDATA[
<![CDATA[
//*************************** FNV64.h ****************************// //*************************** FNV64.h ****************************//
//***************** See RFC NNNN for details. ********************// //***************** See RFC 9923 for details. ********************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#ifndef _FNV64_H_ #ifndef _FNV64_H_
#define _FNV64_H_ #define _FNV64_H_
/* Description: /*
* Description:
* This file provides headers for the 64-bit version of * This file provides headers for the 64-bit version of
* the FNV-1a non-cryptographic hash algorithm. * the FNV-1a non-cryptographic hash algorithm.
*/ */
#include "FNVconfig.h" #include "FNVconfig.h"
#include "FNVErrorCodes.h" #include "FNVErrorCodes.h"
#include <stdint.h> #include <stdint.h>
#define FNV64size (64/8) #define FNV64size (64/8)
#ifdef FNV_64bitIntegers #ifdef FNV_64bitIntegers
#define FNV64basis 0xCBF29CE484222325 #define FNV64basis 0xCBF29CE484222325
#endif #endif
/* If you do not have the ISO standard stdint.h header file, then /* If you do not have the ISO standard stdint.h header file, then
* you must typedef the following types: * you must typedef the following types:
* *
* type meaning * type meaning
* uint64_t unsigned 64-bit integer (ifdef FNV_64bitIntegers) * uint64_t unsigned 64-bit integer (ifdef FNV_64bitIntegers)
* uint32_t unsigned 32-bit integer * uint32_t unsigned 32-bit integer
* uint16_t unsigned 16-bit integer * uint16_t unsigned 16-bit integer
* uint8_t unsigned 8-bit integer (i.e., unsigned char) * uint8_t unsigned 8-bit integer (i.e., unsigned char)
*/ */
/* /*
* This structure holds context information for an FNV64 hash * This structure holds context information for an FNV64 hash
*/ */
#ifdef FNV_64bitIntegers #ifdef FNV_64bitIntegers
/* version if 64-bit integers supported */ /* version if 64-bit integers supported */
typedef struct FNV64context_s { typedef struct FNV64context_s {
int Computed; /* state */ int Computed; /* state */
uint64_t Hash; uint64_t Hash;
skipping to change at line 1718 skipping to change at line 1670
int Computed; /* state */ int Computed; /* state */
uint16_t Hash[FNV64size/2]; uint16_t Hash[FNV64size/2];
} FNV64context; } FNV64context;
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
/* Function Prototypes: /* Function Prototypes:
* *
* FNV64string: hash a zero-terminated string not including * FNV64string: hash a zero-terminated string not including
* the terminating zero * the terminating zero
* FNV164stringBasis: also takes an offset_basis parameter * FNV64stringBasis: also takes an offset_basis parameter
* *
* FNV64block: hash a specified length byte vector * FNV64block: hash a byte vector of a specified length
* FNV64blockBasis: also takes an offset_basis parameter * FNV64blockBasis: also takes an offset_basis parameter
* *
* FNV64file: hash the contents of a file * FNV64file: hash the contents of a file
* FNV128fileBasis: also takes an offset_basis parameter * FNV64fileBasis: also takes an offset_basis parameter
* *
* FNV64init: initializes an FNV64 context * FNV64init: initializes an FNV64 context
* FNV64initBasis: initializes an FNV64 context with a * FNV64initBasis: initializes an FNV64 context with a
* provided 8-byte vector basis * provided 8-byte vector basis
* FNV64blockin: hash in a specified length byte vector * FNV64blockin: hash in a byte vector of a specified length
* FNV64stringin: hash in a zero-terminated string not * FNV64stringin: hash in a zero-terminated string not
* including the terminating zero * including the terminating zero
* FNV128filein: hash in the contents of a file * FNV64filein: hash in the contents of a file
* FNV64result: returns the hash value * FNV64result: returns the hash value
* *
* Hash is returned as an 8-byte vector by the functions above. * Hash is returned as an 8-byte vector by the functions above.
* If 64-bit integers are supported, the following return * If 64-bit integers are supported, the following return
* a 64-bit integer. * a 64-bit integer.
* *
* FNV64INTstring: hash a zero-terminated string not including * FNV64INTstring: hash a zero-terminated string not including
* the terminating zero * the terminating zero
* FNV32INTstringBasis: also takes an offset_basis parameter * FNV64INTstringBasis: also takes an offset_basis parameter
* *
* FNV64INTblock: hash a specified length byte vector * FNV64INTblock: hash a byte vector of a specified length
* FNV32INTblockBasis: also takes an offset_basis parameter * FNV64INTblockBasis: also takes an offset_basis parameter
* *
* FNV64INTfile: hash the contents of a file * FNV64INTfile: hash the contents of a file
* FNV32INTfileBasis: also takes an offset_basis parameter * FNV64INTfileBasis: also takes an offset_basis parameter
* *
* FNV64INTinitBasis: initializes an FNV32 context with a * FNV64INTinitBasis: initializes an FNV64 context with a
* provided 64-bit integer basis * provided 64-bit integer basis
* FNV64INTresult: returns the hash value * FNV64INTresult: returns the hash value
*/ */
#ifdef __cplusplus #ifdef __cplusplus
extern "C" { extern "C" {
#endif #endif
/* FNV64 */ /* FNV64 */
extern int FNV64string ( const char *in, extern int FNV64string ( const char *in,
skipping to change at line 1820 skipping to change at line 1772
uint64_t * const out ); uint64_t * const out );
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
#ifdef __cplusplus #ifdef __cplusplus
} }
#endif #endif
#endif /* _FNV64_H_ */ #endif /* _FNV64_H_ */
]]></sourcecode> ]]></sourcecode>
<sourcecode type="C" markers="true" name="FNV64.c"> <sourcecode type="c" markers="true" name="FNV64.c"><![CDATA[
<![CDATA[
//*************************** FNV64.c ****************************// //*************************** FNV64.c ****************************//
//****************** See RFC NNNN for details ********************// //****************** See RFC 9923 for details. *******************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic /* This file implements the FNV (Fowler/Noll/Vo) non-cryptographic
* hash function FNV-1a for 64-bit hashes. * hash function FNV-1a for 64-bit hashes.
*/ */
#include <stdio.h> #include <stdio.h>
#include "FNVconfig.h" #include "FNVconfig.h"
#include "fnv-private.h" #include "fnv-private.h"
#include "FNV64.h" #include "FNV64.h"
//***************************************************************** //*****************************************************************
skipping to change at line 1923 skipping to change at line 1874
} }
//***************************************************************** //*****************************************************************
// START VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC // START VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC
//***************************************************************** //*****************************************************************
#ifdef FNV_64bitIntegers #ifdef FNV_64bitIntegers
/* 64-bit FNV_prime = 2^40 + 2^8 + 0xb3 */ /* 64-bit FNV_prime = 2^40 + 2^8 + 0xb3 */
#define FNV64prime 0x00000100000001B3 #define FNV64prime 0x00000100000001B3
/* FNV64 hash a zero-terminated string not including the zero /* FNV64: hash a zero-terminated string not including the zero
* to a 64-bit integer (64-bit) * to a 64-bit integer (64-bit)
******************************************************************/ ******************************************************************/
int FNV64INTstring ( const char *in, uint64_t * const out ) { int FNV64INTstring ( const char *in, uint64_t * const out ) {
return FNV64INTstringBasis (in, out, FNV64basis ); return FNV64INTstringBasis ( in, out, FNV64basis );
} /* end FNV64INTstring */ } /* end FNV64INTstring */
/* FNV64 hash a zero-terminated string not including the zero /* FNV64: hash a zero-terminated string not including the zero
* to a 64-bit integer (64-bit) with a non-standard basis * to a 64-bit integer (64-bit) with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV64INTstringBasis ( const char *in, int FNV64INTstringBasis ( const char *in,
uint64_t * const out, uint64_t * const out,
uint64_t basis ) { uint64_t basis ) {
uint64_t temp; uint64_t temp;
uint8_t ch; uint8_t ch;
if ( !in || !out ) if ( !in || !out )
return fnvNull; /* Null input pointer */ return fnvNull; /* Null input pointer */
temp = basis; temp = basis;
while ( (ch = *in++) ) while ( (ch = *in++) )
temp = FNV64prime * ( temp ^ ch ); temp = FNV64prime * ( temp ^ ch );
*out = temp; *out = temp;
return fnvSuccess; return fnvSuccess;
} /* end FNV64INTstringBasis */ } /* end FNV64INTstringBasis */
/* FNV64 hash a zero-terminated string to a 64-bit integer /* FNV64: hash a zero-terminated string to a 64-bit integer
* to a byte vector (64-bit) * to a byte vector (64-bit)
******************************************************************/ ******************************************************************/
int FNV64string ( const char *in, uint8_t out[FNV64size] ) { int FNV64string ( const char *in, uint8_t out[FNV64size] ) {
uint64_t temp; uint64_t temp;
uint8_t ch; uint8_t ch;
if ( !in || !out ) if ( !in || !out )
return fnvNull; /* Null input pointer */ return fnvNull; /* Null input pointer */
temp = FNV64basis; temp = FNV64basis;
while ( (ch = *in++) ) while ( (ch = *in++) )
temp = FNV64prime * ( temp ^ ch ); temp = FNV64prime * ( temp ^ ch );
for ( int i=0; i<FNV64size; ++i ) for ( int i=0; i<FNV64size; ++i )
out[i] = ((uint8_t *)&temp)[i]; out[i] = ((uint8_t *)&temp)[i];
return fnvSuccess; return fnvSuccess;
} /* end FNV64string */ } /* end FNV64string */
/* FNV64 hash a zero-terminated string to a 64-bit integer /* FNV64: hash a zero-terminated string to a 64-bit integer
* to a byte vector (64-bit) with a non-standard basis * to a byte vector (64-bit) with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV64stringBasis ( const char *in, int FNV64stringBasis ( const char *in,
uint8_t out[FNV64size], uint8_t out[FNV64size],
const uint8_t basis[FNV64size] ) { const uint8_t basis[FNV64size] ) {
uint64_t temp; uint64_t temp;
int i; int i;
uint8_t ch; uint8_t ch;
if ( !in || !out || !basis ) if ( !in || !out || !basis )
skipping to change at line 1987 skipping to change at line 1938
temp = basis[7]; temp = basis[7];
for ( i = FNV64size-2; i>=0; --i ) for ( i = FNV64size-2; i>=0; --i )
temp = (temp<<8) + basis[i]; temp = (temp<<8) + basis[i];
while ( (ch = *in++) ) while ( (ch = *in++) )
temp = FNV64prime * ( temp ^ ch ); temp = FNV64prime * ( temp ^ ch );
for ( i=0; i<FNV64size; ++i ) for ( i=0; i<FNV64size; ++i )
out[i] = ((uint8_t *)&temp)[i]; out[i] = ((uint8_t *)&temp)[i];
return fnvSuccess; return fnvSuccess;
} /* end FNV64stringBasis */ } /* end FNV64stringBasis */
/* FNV64 hash a counted block to a 64-bit integer (64-bit) /* FNV64: hash a counted block to a 64-bit integer (64-bit)
******************************************************************/ ******************************************************************/
int FNV64INTblock ( const void *vin, int FNV64INTblock ( const void *vin,
long int length, long int length,
uint64_t * const out ) { uint64_t * const out ) {
return FNV64INTblockBasis ( vin, length, out, FNV64basis ); return FNV64INTblockBasis ( vin, length, out, FNV64basis );
} /* end FNV64INTblock */ } /* end FNV64INTblock */
/* FNV64 hash a counted block to a 64-bit integer (64-bit) /* FNV64: hash a counted block to a 64-bit integer (64-bit)
* with a non-standard basis * with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV64INTblockBasis ( const void *vin, int FNV64INTblockBasis ( const void *vin,
long int length, long int length,
uint64_t * const out, uint64_t * const out,
uint64_t basis ) { uint64_t basis ) {
const uint8_t *in = (const uint8_t*)vin; const uint8_t *in = (const uint8_t*)vin;
uint64_t temp; uint64_t temp;
if ( !in || !out ) if ( !in || !out )
return fnvNull; /* Null input/out pointer */ return fnvNull;
/* Null input pointer or null output pointer */
if ( length < 0 ) if ( length < 0 )
return fnvBadParam; return fnvBadParam;
for ( temp = basis; length > 0; length-- ) for ( temp = basis; length > 0; length-- )
temp = FNV64prime * ( temp ^ *in++ ); temp = FNV64prime * ( temp ^ *in++ );
*out = temp; *out = temp;
return fnvSuccess; return fnvSuccess;
} /* end FNV64INTblockBasis */ } /* end FNV64INTblockBasis */
/* FNV64 hash a counted block to a byte vector (64-bit) /* FNV64: hash a counted block to a byte vector (64-bit)
******************************************************************/ ******************************************************************/
int FNV64block ( const void *vin, int FNV64block ( const void *vin,
long int length, long int length,
uint8_t out[FNV64size] ) { uint8_t out[FNV64size] ) {
const uint8_t *in = (const uint8_t*)vin; const uint8_t *in = (const uint8_t*)vin;
uint64_t temp; uint64_t temp;
if ( !in || !out ) if ( !in || !out )
return fnvNull; /* Null input/out pointer */ return fnvNull;
/* Null input pointer or null output pointer */
if ( length < 0 ) if ( length < 0 )
return fnvBadParam; return fnvBadParam;
for ( temp = FNV64basis; length > 0; length-- ) for ( temp = FNV64basis; length > 0; length-- )
temp = FNV64prime * ( temp ^ *in++ ); temp = FNV64prime * ( temp ^ *in++ );
for ( int i=0; i<FNV64size; ++i ) for ( int i=0; i<FNV64size; ++i )
out[i] = ((uint8_t *)&temp)[i]; out[i] = ((uint8_t *)&temp)[i];
return fnvSuccess; return fnvSuccess;
} /* end FNV64block */ } /* end FNV64block */
/* FNV64 hash a counted block to a byte vector (64-bit) /* FNV64: hash a counted block to a byte vector (64-bit)
* with a non-standard basis * with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV64blockBasis ( const void *vin, int FNV64blockBasis ( const void *vin,
long int length, long int length,
uint8_t out[FNV64size], uint8_t out[FNV64size],
const uint8_t basis[FNV64size] ) { const uint8_t basis[FNV64size] ) {
const uint8_t *in = (const uint8_t*)vin; const uint8_t *in = (const uint8_t*)vin;
uint64_t temp; uint64_t temp;
int i; int i;
if ( !in || !out || !basis ) if ( !in || !out || !basis )
return fnvNull; /* Null input/out pointer */ return fnvNull;
/* Null input pointer or null output pointer */
if ( length < 0 ) if ( length < 0 )
return fnvBadParam; return fnvBadParam;
temp = basis[7]; temp = basis[7];
for ( i = FNV64size-2; i>=0; --i ) for ( i = FNV64size-2; i>=0; --i )
temp = (temp<<8) + basis[i]; temp = (temp<<8) + basis[i];
for (; length > 0; length-- ) for (; length > 0; length-- )
temp = FNV64prime * ( temp ^ *in++ ); temp = FNV64prime * ( temp ^ *in++ );
for ( i=0; i<FNV64size; ++i ) for ( i=0; i<FNV64size; ++i )
out[i] = ((uint8_t *)&temp)[i]; out[i] = ((uint8_t *)&temp)[i];
return fnvSuccess; return fnvSuccess;
} /* end FNV64blockBasis */ } /* end FNV64blockBasis */
//***************************************************************** //*****************************************************************
// Set of init, input, and output functions below // Set of init, input, and output functions below
// to incrementally compute FNV64 // to incrementally compute FNV64
//***************************************************************** //*****************************************************************
/* initialize context (64-bit) /* initialize context (64-bit)
******************************************************************/ ******************************************************************/
int FNV64init( FNV64context * const ctx ) { int FNV64init( FNV64context * const ctx ) {
return FNV64INTinitBasis ( ctx, FNV64basis ); return FNV64INTinitBasis ( ctx, FNV64basis );
} /* end FNV64init */ } /* end FNV64init */
/* initialize context with a provided 64-bit integer basis (64-bit) /* initialize context with a provided 64-bit integer basis (64-bit)
******************************************************************/ ******************************************************************/
skipping to change at line 2119 skipping to change at line 2073
break; break;
default: default:
return fnvStateError; return fnvStateError;
} }
for ( temp = ctx->Hash; length > 0; length-- ) for ( temp = ctx->Hash; length > 0; length-- )
temp = FNV64prime * ( temp ^ *in++ ); temp = FNV64prime * ( temp ^ *in++ );
ctx->Hash = temp; ctx->Hash = temp;
return fnvSuccess; return fnvSuccess;
} /* end FNV64blockin */ } /* end FNV64blockin */
/* hash in a zero-terminated string not including the zero (64-bit) /* hash in a zero-terminated string not including the zero (64-bit)
******************************************************************/ ******************************************************************/
int FNV64stringin ( FNV64context * const ctx, const char *in ) { int FNV64stringin ( FNV64context * const ctx, const char *in ) {
uint64_t temp; uint64_t temp;
uint8_t ch; uint8_t ch;
if ( !ctx || !in ) if ( !ctx || !in )
return fnvNull; return fnvNull;
switch ( ctx->Computed ) { switch ( ctx->Computed ) {
case FNVinited+FNV64state: case FNVinited+FNV64state:
ctx->Computed = FNVcomputed+FNV64state; ctx->Computed = FNVcomputed+FNV64state;
skipping to change at line 2143 skipping to change at line 2097
default: default:
return fnvStateError; return fnvStateError;
} }
temp = ctx->Hash; temp = ctx->Hash;
while ( (ch = (uint8_t)*in++) ) while ( (ch = (uint8_t)*in++) )
temp = FNV64prime * ( temp ^ ch ); temp = FNV64prime * ( temp ^ ch );
ctx->Hash = temp; ctx->Hash = temp;
return fnvSuccess; return fnvSuccess;
} /* end FNV64stringin */ } /* end FNV64stringin */
/* return hash as 64-bit int (64-bit) /* return hash as 64-bit int (64-bit)
******************************************************************/ ******************************************************************/
int FNV64INTresult ( FNV64context * const ctx, int FNV64INTresult ( FNV64context * const ctx,
uint64_t * const out ) { uint64_t * const out ) {
if ( !ctx || !out ) if ( !ctx || !out )
return fnvNull; return fnvNull;
if ( ctx->Computed != FNVcomputed+FNV64state ) if ( ctx->Computed != FNVcomputed+FNV64state )
return fnvStateError; return fnvStateError;
ctx->Computed = FNVemptied+FNV64state; ctx->Computed = FNVemptied+FNV64state;
*out = ctx->Hash; *out = ctx->Hash;
ctx->Hash = 0; ctx->Hash = 0;
return fnvSuccess; return fnvSuccess;
} /* end FNV64INTresult */ } /* end FNV64INTresult */
/* return hash as 8-byte vector (64-bit) /* return hash as 8-byte vector (64-bit)
******************************************************************/ ******************************************************************/
int FNV64result ( FNV64context * const ctx, int FNV64result ( FNV64context * const ctx,
uint8_t out[FNV64size] ) { uint8_t out[FNV64size] ) {
if ( !ctx || !out ) if ( !ctx || !out )
return fnvNull; return fnvNull;
if ( ctx->Computed != FNVcomputed+FNV64state ) if ( ctx->Computed != FNVcomputed+FNV64state )
return fnvStateError; return fnvStateError;
ctx->Computed = FNVemptied+FNV64state; ctx->Computed = FNVemptied+FNV64state;
for ( int i=0; i<FNV64size; ++i ) for ( int i=0; i<FNV64size; ++i )
out[i] = ((uint8_t *)&ctx->Hash)[i]; out[i] = ((uint8_t *)&ctx->Hash)[i];
skipping to change at line 2219 skipping to change at line 2173
#else /* FNV_64bitIntegers */ #else /* FNV_64bitIntegers */
//*************************************************************** //***************************************************************
// START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//*************************************************************** //***************************************************************
/* 64-bit FNV_prime = 2^40 + 2^8 + 0xb3 */ /* 64-bit FNV_prime = 2^40 + 2^8 + 0xb3 */
/* #define FNV64prime 0x00000100000001B3 */ /* #define FNV64prime 0x00000100000001B3 */
#define FNV64primeX 0x01B3 #define FNV64primeX 0x01B3
#define FNV64shift 8 #define FNV64shift 8
/* FNV64 hash a zero-terminated string not including the zero /* FNV64: hash a zero-terminated string not including the zero
******************************************************************/ ******************************************************************/
int FNV64string ( const char *in, uint8_t out[FNV64size] ) { int FNV64string ( const char *in, uint8_t out[FNV64size] ) {
FNV64context ctx; FNV64context ctx;
int error; int error;
if ( (error = FNV64init (&ctx)) ) if ( (error = FNV64init (&ctx)) )
return error; return error;
if ( (error = FNV64stringin (&ctx, in)) ) if ( (error = FNV64stringin (&ctx, in)) )
return error; return error;
return FNV64result (&ctx, out); return FNV64result (&ctx, out);
} /* end FNV64string */ } /* end FNV64string */
/* FNV64 hash a zero-terminated string not including the zero /* FNV64: hash a zero-terminated string not including the zero
* with a non-standard offset_basis * with a non-standard offset_basis
******************************************************************/ ******************************************************************/
int FNV64stringBasis ( const char *in, int FNV64stringBasis ( const char *in,
uint8_t out[FNV64size], uint8_t out[FNV64size],
const uint8_t basis[FNV64size] ) { const uint8_t basis[FNV64size] ) {
FNV64context ctx; FNV64context ctx;
int error; int error;
if ( (error = FNV64initBasis (&ctx, basis)) ) if ( (error = FNV64initBasis (&ctx, basis)) )
return error; return error;
if ( (error = FNV64stringin (&ctx, in)) ) if ( (error = FNV64stringin (&ctx, in)) )
return error; return error;
return FNV64result (&ctx, out); return FNV64result (&ctx, out);
} /* end FNV64stringBasis */ } /* end FNV64stringBasis */
/* FNV64 hash a counted block /* FNV64: hash a counted block
******************************************************************/ ******************************************************************/
int FNV64block ( const void *vin, int FNV64block ( const void *vin,
long int length, long int length,
uint8_t out[FNV64size] ) { uint8_t out[FNV64size] ) {
FNV64context ctx; FNV64context ctx;
int error; int error;
if ( (error = FNV64init (&ctx)) ) if ( (error = FNV64init (&ctx)) )
return error; return error;
if ( (error = FNV64blockin (&ctx, vin, length)) ) if ( (error = FNV64blockin (&ctx, vin, length)) )
return error; return error;
return FNV64result (&ctx, out); return FNV64result (&ctx, out);
} /* end FNV64block */ } /* end FNV64block */
/* FNV64 hash a counted block with a non-standard offset_basis /* FNV64: hash a counted block with a non-standard offset_basis
******************************************************************/ ******************************************************************/
int FNV64blockBasis ( const void *vin, int FNV64blockBasis ( const void *vin,
long int length, long int length,
uint8_t out[FNV64size], uint8_t out[FNV64size],
const uint8_t basis[FNV64size] ) { const uint8_t basis[FNV64size] ) {
FNV64context ctx; FNV64context ctx;
int error; int error;
if ( (error = FNV64initBasis (&ctx, basis)) ) if ( (error = FNV64initBasis (&ctx, basis)) )
return error; return error;
skipping to change at line 2297 skipping to change at line 2251
if ( !ctx ) if ( !ctx )
return fnvNull; return fnvNull;
ctx->Hash[0] = 0xCBF2; ctx->Hash[0] = 0xCBF2;
ctx->Hash[1] = 0x9CE4; ctx->Hash[1] = 0x9CE4;
ctx->Hash[2] = 0x8422; ctx->Hash[2] = 0x8422;
ctx->Hash[3] = 0x2325; ctx->Hash[3] = 0x2325;
ctx->Computed = FNVinited+FNV64state; ctx->Computed = FNVinited+FNV64state;
return fnvSuccess; return fnvSuccess;
} /* end FNV64init */ } /* end FNV64init */
/* initialize context with a non-standard basis (32-bit) /* initialize context with a non-standard basis (32-bit)
******************************************************************/ ******************************************************************/
int FNV64initBasis ( FNV64context * const ctx, int FNV64initBasis ( FNV64context * const ctx,
const uint8_t basis[FNV64size] ) { const uint8_t basis[FNV64size] ) {
if ( !ctx || !basis ) if ( !ctx || !basis )
return fnvNull; return fnvNull;
for ( int i=0; i < FNV64size/2; ++i ) { for ( int i=0; i < FNV64size/2; ++i ) {
uint32_t temp = *basis++; uint32_t temp = *basis++;
ctx->Hash[i] = ( temp<<8 ) + *basis++; ctx->Hash[i] = ( temp<<8 ) + *basis++;
} }
ctx->Computed = FNVinited+FNV64state; ctx->Computed = FNVinited+FNV64state;
return fnvSuccess; return fnvSuccess;
} /* end FNV64initBasis */ } /* end FNV64initBasis */
/* hash in a counted block (32-bit) /* hash in a counted block (32-bit)
******************************************************************/ ******************************************************************/
int FNV64blockin ( FNV64context * const ctx, int FNV64blockin ( FNV64context * const ctx,
const void *vin, const void *vin,
long int length ) { long int length ) {
skipping to change at line 2423 skipping to change at line 2377
//***************************************************************** //*****************************************************************
// END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//***************************************************************** //*****************************************************************
]]></sourcecode> ]]></sourcecode>
</section> </section>
<section> <section>
<name>FNV128 Code</name> <name>FNV128 Code</name>
<t>The header and C source for 128-bit FNV-1a providing a byte <t>The following code is the header and C source for 128-bit FNV-1a providing a byte
vector hash.</t> vector hash.</t>
<sourcecode type="C" markers="true" name="FNV128.h"> <sourcecode type="c" markers="true" name="FNV128.h"><![CDATA[
<![CDATA[
//************************** FNV128.h ************************// //************************** FNV128.h ************************//
//*************** See RFC NNNN for details. ******************// //*************** See RFC 9923 for details. ******************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#ifndef _FNV128_H_ #ifndef _FNV128_H_
#define _FNV128_H_ #define _FNV128_H_
/* /*
* Description: * Description:
* This file provides headers for the 128-bit version of * This file provides headers for the 128-bit version of
skipping to change at line 2485 skipping to change at line 2438
} FNV128context; } FNV128context;
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
/* Function Prototypes: /* Function Prototypes:
* *
* FNV128string: hash a zero-terminated string not including * FNV128string: hash a zero-terminated string not including
* the terminating zero * the terminating zero
* FNV128stringBasis: also takes an offset_basis parameter * FNV128stringBasis: also takes an offset_basis parameter
* *
* FNV128block: hash a specified length byte vector * FNV128block: hash a byte vector of a specified length
* FNV128blockBasis: also takes an offset_basis parameter * FNV128blockBasis: also takes an offset_basis parameter
* *
* FNV128file: hash the contents of a file * FNV128file: hash the contents of a file
* FNV128fileBasis: also takes an offset_basis parameter * FNV128fileBasis: also takes an offset_basis parameter
* *
* FNV128init: initializes an FNV128 context * FNV128init: initializes an FNV128 context
* FNV128initBasis: initializes an FNV128 context with a * FNV128initBasis: initializes an FNV128 context with a
* provided 16-byte vector basis * provided 16-byte vector basis
* FNV128blockin: hash in a specified length byte vector * FNV128blockin: hash in a byte vector of a specified length
* FNV128stringin: hash in a zero-terminated string not * FNV128stringin: hash in a zero-terminated string not
* including the terminating zero * including the terminating zero
* FNV128filein: hash in the contents of a file * FNV128filein: hash in the contents of a file
* FNV128result: returns the hash value * FNV128result: returns the hash value
* *
* Hash is returned as an array of 8-bit unsigned integers * Hash is returned as an array of 8-bit unsigned integers
*/ */
#ifdef __cplusplus #ifdef __cplusplus
extern "C" { extern "C" {
skipping to change at line 2545 skipping to change at line 2498
extern int FNV128result ( FNV128context * const, extern int FNV128result ( FNV128context * const,
uint8_t out[FNV128size] ); uint8_t out[FNV128size] );
#ifdef __cplusplus #ifdef __cplusplus
} }
#endif #endif
#endif /* _FNV128_H_ */ #endif /* _FNV128_H_ */
]]></sourcecode> ]]></sourcecode>
<sourcecode type="C" markers="true" name="FNV128.c"> <sourcecode type="c" markers="true" name="FNV128.c"><![CDATA[
<![CDATA[
//**************************** FNV128.c **************************// //**************************** FNV128.c **************************//
//******************* See RFC NNNN for details *******************// //******************* See RFC 9923 for details. ******************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic /* This file implements the FNV (Fowler/Noll/Vo) non-cryptographic
* hash function FNV-1a for 128-bit hashes. * hash function FNV-1a for 128-bit hashes.
*/ */
#include <stdio.h> #include <stdio.h>
#include "FNVconfig.h" #include "FNVconfig.h"
#include "fnv-private.h" #include "fnv-private.h"
#include "FNV128.h" #include "FNV128.h"
//***************************************************************** //*****************************************************************
// COMMON CODE FOR 64- AND 32-BIT INTEGER MODES // COMMON CODE FOR 64- AND 32-BIT INTEGER MODES
//***************************************************************** //*****************************************************************
/* FNV128 hash a zero-terminated string not including the zero /* FNV128: hash a zero-terminated string not including the zero
******************************************************************/ ******************************************************************/
int FNV128string ( const char *in, uint8_t out[FNV128size] ) { int FNV128string ( const char *in, uint8_t out[FNV128size] ) {
FNV128context ctx; FNV128context ctx;
int error; int error;
if ( (error = FNV128init ( &ctx )) ) if ( (error = FNV128init ( &ctx )) )
return error; return error;
if ( (error = FNV128stringin ( &ctx, in )) ) if ( (error = FNV128stringin ( &ctx, in )) )
return error; return error;
return FNV128result (&ctx, out); return FNV128result (&ctx, out);
} /* end FNV128string */ } /* end FNV128string */
/* FNV128 hash a zero-terminated string not including the zero /* FNV128: hash a zero-terminated string not including the zero
******************************************************************/ ******************************************************************/
int FNV128stringBasis ( const char *in, int FNV128stringBasis ( const char *in,
uint8_t out[FNV128size], uint8_t out[FNV128size],
const uint8_t basis[FNV128size] ) { const uint8_t basis[FNV128size] ) {
FNV128context ctx; FNV128context ctx;
int error; int error;
if ( (error = FNV128initBasis ( &ctx, basis )) ) if ( (error = FNV128initBasis ( &ctx, basis )) )
return error; return error;
if ( (error = FNV128stringin ( &ctx, in )) ) if ( (error = FNV128stringin ( &ctx, in )) )
return error; return error;
return FNV128result ( &ctx, out ); return FNV128result ( &ctx, out );
} /* end FNV128stringBasis */ } /* end FNV128stringBasis */
/* FNV128 hash a counted block (64/32-bit) /* FNV128: hash a counted block (64/32-bit)
******************************************************************/ ******************************************************************/
int FNV128block ( const void *vin, int FNV128block ( const void *vin,
long int length, long int length,
uint8_t out[FNV128size] ) { uint8_t out[FNV128size] ) {
FNV128context ctx; FNV128context ctx;
int error; int error;
if ( (error = FNV128init ( &ctx )) ) if ( (error = FNV128init ( &ctx )) )
return error; return error;
if ( (error = FNV128blockin ( &ctx, vin, length )) ) if ( (error = FNV128blockin ( &ctx, vin, length )) )
return error; return error;
return FNV128result ( &ctx, out ); return FNV128result ( &ctx, out );
} /* end FNV128block */ } /* end FNV128block */
/* FNV128 hash a counted block (64/32-bit) /* FNV128: hash a counted block (64/32-bit)
******************************************************************/ ******************************************************************/
int FNV128blockBasis ( const void *vin, int FNV128blockBasis ( const void *vin,
long int length, long int length,
uint8_t out[FNV128size], uint8_t out[FNV128size],
const uint8_t basis[FNV128size] ) { const uint8_t basis[FNV128size] ) {
FNV128context ctx; FNV128context ctx;
int error; int error;
if ( (error = FNV128initBasis ( &ctx, basis )) ) if ( (error = FNV128initBasis ( &ctx, basis )) )
return error; return error;
skipping to change at line 2698 skipping to change at line 2650
fclose(fp); fclose(fp);
return error; return error;
} }
error = ferror(fp); error = ferror(fp);
fclose(fp); fclose(fp);
if (error) return fnvBadParam; if (error) return fnvBadParam;
return fnvSuccess; return fnvSuccess;
} /* end FNV128filein */ } /* end FNV128filein */
//***************************************************************** //*****************************************************************
// START VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC // START VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC
//***************************************************************** //*****************************************************************
#ifdef FNV_64bitIntegers #ifdef FNV_64bitIntegers
/* 128-bit FNV_prime = 2^88 + 2^8 + 0x3b */ /* 128-bit FNV_prime = 2^88 + 2^8 + 0x3b */
/* 0x00000000 01000000 00000000 0000013B */ /* 0x00000000 01000000 00000000 0000013B */
#define FNV128primeX 0x013B #define FNV128primeX 0x013B
#define FNV128shift 24 #define FNV128shift 24
//***************************************************************** //*****************************************************************
// Set of init, input, and output functions below // Set of init, input, and output functions below
skipping to change at line 2826 skipping to change at line 2778
for ( i = 3; i > 0; --i ) { for ( i = 3; i > 0; --i ) {
temp[i-1] += temp[i] >> 32; temp[i-1] += temp[i] >> 32;
temp[i] &= 0xFFFFFFFF; temp[i] &= 0xFFFFFFFF;
} }
} }
for ( i=0; i<FNV128size/4; ++i ) for ( i=0; i<FNV128size/4; ++i )
ctx->Hash[i] = (uint32_t)temp[i]; ctx->Hash[i] = (uint32_t)temp[i];
return fnvSuccess; return fnvSuccess;
} /* end FNV128stringin */ } /* end FNV128stringin */
/* return hash as 16-byte vector (64-bit) /* return hash as 16-byte vector (64-bit)
******************************************************************/ ******************************************************************/
int FNV128result ( FNV128context * const ctx, int FNV128result ( FNV128context * const ctx,
uint8_t out[FNV128size] ) { uint8_t out[FNV128size] ) {
if ( !ctx || !out ) if ( !ctx || !out )
return fnvNull; return fnvNull;
if ( ctx->Computed != FNVcomputed+FNV128state ) if ( ctx->Computed != FNVcomputed+FNV128state )
return fnvStateError; return fnvStateError;
for ( int i=0; i<FNV128size/4; ++i ) { for ( int i=0; i<FNV128size/4; ++i ) {
out[4*i] = ctx->Hash[i] >> 24; out[4*i] = ctx->Hash[i] >> 24;
out[4*i+1] = ctx->Hash[i] >> 16; out[4*i+1] = ctx->Hash[i] >> 16;
skipping to change at line 2886 skipping to change at line 2838
} /* end FNV128init */ } /* end FNV128init */
/* initialize context with a provided 16-byte vector basis (32-bit) /* initialize context with a provided 16-byte vector basis (32-bit)
******************************************************************/ ******************************************************************/
int FNV128initBasis ( FNV128context * const ctx, int FNV128initBasis ( FNV128context * const ctx,
const uint8_t basis[FNV128size] ) { const uint8_t basis[FNV128size] ) {
if ( !ctx || !basis ) if ( !ctx || !basis )
return fnvNull; return fnvNull;
for ( int i=0; i < FNV128size/2; ++i ) { for ( int i=0; i < FNV128size/2; ++i ) {
uint32_t temp = *basis++; uint32_t temp = *basis++;
ctx->Hash[i] = ( temp<<8 ) + *basis++; ctx->Hash[i] = ( temp<<8 ) + *basis++;
} }
ctx->Computed = FNVinited+FNV128state; ctx->Computed = FNVinited+FNV128state;
return fnvSuccess; return fnvSuccess;
} /* end FNV128initBasis */ } /* end FNV128initBasis */
/* hash in a counted block (32-bit) /* hash in a counted block (32-bit)
*****************************************************************/ *****************************************************************/
int FNV128blockin ( FNV128context * const ctx, int FNV128blockin ( FNV128context * const ctx,
const void *vin, const void *vin,
long int length ) { long int length ) {
skipping to change at line 2995 skipping to change at line 2947
out[2*i] = ctx->Hash[i] >> 8; out[2*i] = ctx->Hash[i] >> 8;
out[2*i+1] = ctx->Hash[i]; out[2*i+1] = ctx->Hash[i];
ctx -> Hash[i] = 0; ctx -> Hash[i] = 0;
} }
ctx->Computed = FNVemptied+FNV128state; ctx->Computed = FNVemptied+FNV128state;
return fnvSuccess; return fnvSuccess;
} /* end FNV128result */ } /* end FNV128result */
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
//****************************************************************** //******************************************************************
// END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//****************************************************************** //******************************************************************
]]></sourcecode> ]]></sourcecode>
</section> </section>
<section> <section>
<name>FNV256 Code</name> <name>FNV256 Code</name>
<t>The header and C source for 256-bit FNV-1a providing a byte <t>The following code is the header and C source for 256-bit FNV-1a providing a byte
vector hash.</t> vector hash.</t>
<sourcecode type="C" markers="true" name="FNV256.h"> <sourcecode type="c" markers="true" name="FNV256.h"><![CDATA[
<![CDATA[
//************************* FNV256.h ***********************// //************************* FNV256.h ***********************//
//************** See RFC NNNN for details. *****************// //************** See RFC 9923 for details. *****************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#ifndef _FNV256_H_ #ifndef _FNV256_H_
#define _FNV256_H_ #define _FNV256_H_
/* /*
* Description: * Description:
* This file provides headers for the 256-bit version of * This file provides headers for the 256-bit version of
skipping to change at line 3064 skipping to change at line 3015
int Computed; /* state */ int Computed; /* state */
uint16_t Hash[FNV256size/2]; uint16_t Hash[FNV256size/2];
} FNV256context; } FNV256context;
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
/* Function Prototypes: /* Function Prototypes:
* *
* FNV256string: hash a zero-terminated string not including * FNV256string: hash a zero-terminated string not including
* the terminating zero * the terminating zero
* FNV246stgringBasis: also takes an offset_basis parameter * FNV256stringBasis: also takes an offset_basis parameter
* *
* FNV256block: hash a specified length byte vector * FNV256block: hash a byte vector of a specified length
* FNV256blockBasis: also takes an offset_basis parameter * FNV256blockBasis: also takes an offset_basis parameter
* *
* FNV256file: hash the contents of a file * FNV256file: hash the contents of a file
* FNV256fileBasis: also takes an offset_basis parameter * FNV256fileBasis: also takes an offset_basis parameter
* *
* FNV256init: initializes an FNV256 context * FNV256init: initializes an FNV256 context
* FNV256initBasis: initializes an FNV256 context with a * FNV256initBasis: initializes an FNV256 context with a
* provided 32-byte vector basis * provided 32-byte vector basis
* FNV256blockin: hash in a specified length byte vector * FNV256blockin: hash in a byte vector of a specified length
* FNV256stringin: hash in a zero-terminated string not * FNV256stringin: hash in a zero-terminated string not
* including the terminating zero * including the terminating zero
* FNV256filein: hash in the contents of a file * FNV256filein: hash in the contents of a file
* FNV256result: returns the hash value * FNV256result: returns the hash value
* *
* Hash is returned as an array of 8-bit unsigned integers * Hash is returned as an array of 8-bit unsigned integers
*/ */
#ifdef __cplusplus #ifdef __cplusplus
extern "C" { extern "C" {
skipping to change at line 3126 skipping to change at line 3077
extern int FNV256result ( FNV256context * const, extern int FNV256result ( FNV256context * const,
uint8_t out[FNV256size] ); uint8_t out[FNV256size] );
#ifdef __cplusplus #ifdef __cplusplus
} }
#endif #endif
#endif /* _FNV256_H_ */ #endif /* _FNV256_H_ */
]]></sourcecode> ]]></sourcecode>
<sourcecode type="C" markers="true" name="FNV256.c"> <sourcecode type="c" markers="true" name="FNV256.c"><![CDATA[
<![CDATA[
//**************************** FNV256.c **************************// //**************************** FNV256.c **************************//
//******************* See RFC NNNN for details *******************// //******************* See RFC 9923 for details. ******************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic /* This file implements the FNV (Fowler/Noll/Vo) non-cryptographic
* hash function FNV-1a for 256-bit hashes. * hash function FNV-1a for 256-bit hashes.
*/ */
#include <stdio.h> #include <stdio.h>
#include "fnv-private.h" #include "fnv-private.h"
#include "FNV256.h" #include "FNV256.h"
//***************************************************************** //*****************************************************************
// COMMON CODE FOR 64- AND 32-BIT INTEGER MODES // COMMON CODE FOR 64- AND 32-BIT INTEGER MODES
//***************************************************************** //*****************************************************************
/* FNV256 hash a zero-terminated string not including the zero /* FNV256: hash a zero-terminated string not including the zero
******************************************************************/ ******************************************************************/
int FNV256string ( const char *in, uint8_t out[FNV256size] ) { int FNV256string ( const char *in, uint8_t out[FNV256size] ) {
FNV256context ctx; FNV256context ctx;
int error; int error;
if ( (error = FNV256init ( &ctx )) ) if ( (error = FNV256init ( &ctx )) )
return error; return error;
if ( (error = FNV256stringin ( &ctx, in )) ) if ( (error = FNV256stringin ( &ctx, in )) )
return error; return error;
return FNV256result ( &ctx, out ); return FNV256result ( &ctx, out );
} /* end FNV256string */ } /* end FNV256string */
/* FNV256 hash a zero-terminated string not including the zero /* FNV256: hash a zero-terminated string not including the zero
* with a non-standard basis * with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV256stringBasis ( const char *in, int FNV256stringBasis ( const char *in,
uint8_t out[FNV256size], uint8_t out[FNV256size],
const uint8_t basis[FNV256size] ) { const uint8_t basis[FNV256size] ) {
FNV256context ctx; FNV256context ctx;
int error; int error;
if ( (error = FNV256initBasis ( &ctx, basis )) ) if ( (error = FNV256initBasis ( &ctx, basis )) )
return error; return error;
if ( (error = FNV256stringin ( &ctx, in )) ) if ( (error = FNV256stringin ( &ctx, in )) )
return error; return error;
return FNV256result ( &ctx, out ); return FNV256result ( &ctx, out );
} /* end FNV256stringBasis */ } /* end FNV256stringBasis */
/* FNV256 hash a counted block (64/32-bit) /* FNV256: hash a counted block (64/32-bit)
******************************************************************/ ******************************************************************/
int FNV256block ( const void *vin, int FNV256block ( const void *vin,
long int length, long int length,
uint8_t out[FNV256size] ) { uint8_t out[FNV256size] ) {
FNV256context ctx; FNV256context ctx;
int error; int error;
if ( (error = FNV256init ( &ctx )) ) if ( (error = FNV256init ( &ctx )) )
return error; return error;
if ( (error = FNV256blockin ( &ctx, vin, length)) ) if ( (error = FNV256blockin ( &ctx, vin, length)) )
return error; return error;
return FNV256result ( &ctx, out ); return FNV256result ( &ctx, out );
} /* end FNV256block */ } /* end FNV256block */
/* FNV256 hash a counted block (64/32-bit) /* FNV256: hash a counted block (64/32-bit)
* with a non-standard basis * with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV256blockBasis ( const void *vin, int FNV256blockBasis ( const void *vin,
long int length, long int length,
uint8_t out[FNV256size], uint8_t out[FNV256size],
const uint8_t basis[FNV256size] ) { const uint8_t basis[FNV256size] ) {
FNV256context ctx; FNV256context ctx;
int error; int error;
if ( (error = FNV256initBasis ( &ctx, basis )) ) if ( (error = FNV256initBasis ( &ctx, basis )) )
skipping to change at line 3280 skipping to change at line 3230
fclose(fp); fclose(fp);
return error; return error;
} }
error = ferror(fp); error = ferror(fp);
fclose(fp); fclose(fp);
if (error) return fnvBadParam; if (error) return fnvBadParam;
return fnvSuccess; return fnvSuccess;
} /* end FNV256filein */ } /* end FNV256filein */
//***************************************************************** //*****************************************************************
// START VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC // START VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC
//***************************************************************** //*****************************************************************
#ifdef FNV_64bitIntegers #ifdef FNV_64bitIntegers
/* 256-bit FNV_prime = 2^168 + 2^8 + 0x63 */ /* 256-bit FNV_prime = 2^168 + 2^8 + 0x63 */
/* 0x0000000000000000 0000010000000000 /* 0x0000000000000000 0000010000000000
0000000000000000 0000000000000163 */ 0000000000000000 0000000000000163 */
#define FNV256primeX 0x0163 #define FNV256primeX 0x0163
#define FNV256shift 8 #define FNV256shift 8
//***************************************************************** //*****************************************************************
skipping to change at line 3431 skipping to change at line 3381
out[4*i+1] = ctx->Hash[i] >> 16; out[4*i+1] = ctx->Hash[i] >> 16;
out[4*i+2] = ctx->Hash[i] >> 8; out[4*i+2] = ctx->Hash[i] >> 8;
out[4*i+3] = ctx->Hash[i]; out[4*i+3] = ctx->Hash[i];
ctx -> Hash[i] = 0; ctx -> Hash[i] = 0;
} }
ctx->Computed = FNVemptied+FNV256state; ctx->Computed = FNVemptied+FNV256state;
return fnvSuccess; return fnvSuccess;
} /* end FNV256result */ } /* end FNV256result */
//**************************************************************** //****************************************************************
// END VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC // END VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC
//**************************************************************** //****************************************************************
#else /* FNV_64bitIntegers */ #else /* FNV_64bitIntegers */
//**************************************************************** //****************************************************************
// START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//**************************************************************** //****************************************************************
/* version for when you only have 32-bit arithmetic
*****************************************************************/
/* 256-bit FNV_prime = 2^168 + 2^8 + 0x63 */ /* 256-bit FNV_prime = 2^168 + 2^8 + 0x63 */
/* 0x00000000 00000000 00000100 00000000 /* 0x00000000 00000000 00000100 00000000
00000000 00000000 00000000 00000163 */ 00000000 00000000 00000000 00000163 */
#define FNV256primeX 0x0163 #define FNV256primeX 0x0163
#define FNV256shift 8 #define FNV256shift 8
//**************************************************************** //****************************************************************
// Set of init, input, and output functions below // Set of init, input, and output functions below
// to incrementally compute FNV256 // to incrementally compute FNV256
//**************************************************************** //****************************************************************
skipping to change at line 3468 skipping to change at line 3415
if ( !ctx ) if ( !ctx )
return fnvNull; return fnvNull;
for ( int i=0; i<FNV256size/2; ++i ) for ( int i=0; i<FNV256size/2; ++i )
ctx->Hash[i] = FNV256basis[i]; ctx->Hash[i] = FNV256basis[i];
ctx->Computed = FNVinited+FNV256state; ctx->Computed = FNVinited+FNV256state;
return fnvSuccess; return fnvSuccess;
} /* end FNV256init */ } /* end FNV256init */
/* initialize context with a provided 32-byte vector basis (32-bit) /* initialize context with a provided 32-byte vector basis (32-bit)
*****************************************************************/ ******************************************************************/
int FNV256initBasis ( FNV256context * const ctx, int FNV256initBasis ( FNV256context * const ctx,
const uint8_t basis[FNV256size] ) { const uint8_t basis[FNV256size] ) {
if ( !ctx || !basis ) if ( !ctx || !basis )
return fnvNull; return fnvNull;
for ( int i=0; i < FNV256size/2; ++i ) { for ( int i=0; i < FNV256size/2; ++i ) {
uint32_t temp = *basis++; uint32_t temp = *basis++;
ctx->Hash[i] = ( temp<<8 ) + (*basis++); ctx->Hash[i] = ( temp<<8 ) + (*basis++);
} }
ctx->Computed = FNVinited+FNV256state; ctx->Computed = FNVinited+FNV256state;
return fnvSuccess; return fnvSuccess;
} /* end FNV256initBasis */ } /* end FNV256initBasis */
/* hash in a counted block (32-bit) /* hash in a counted block (32-bit)
*****************************************************************/ *****************************************************************/
int FNV256blockin ( FNV256context * const ctx, int FNV256blockin ( FNV256context * const ctx,
const void *vin, const void *vin,
long int length ) { long int length ) {
skipping to change at line 3526 skipping to change at line 3473
temp[i-1] += temp[i] >> 16; temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF; temp[i] &= 0xFFFF;
} }
} }
for ( i=0; i<FNV256size/2; ++i ) for ( i=0; i<FNV256size/2; ++i )
ctx->Hash[i] = temp[i]; ctx->Hash[i] = temp[i];
return fnvSuccess; return fnvSuccess;
} /* end FNV256blockin */ } /* end FNV256blockin */
/* hash in a zero-terminated string not including the zero (32-bit) /* hash in a zero-terminated string not including the zero (32-bit)
*****************************************************************/ ******************************************************************/
int FNV256stringin ( FNV256context * const ctx, const char *in ) { int FNV256stringin ( FNV256context * const ctx, const char *in ) {
uint32_t temp[FNV256size/2]; uint32_t temp[FNV256size/2];
uint32_t temp2[6]; uint32_t temp2[6];
int i; int i;
uint8_t ch; uint8_t ch;
if ( !ctx || !in ) if ( !ctx || !in )
return fnvNull; return fnvNull;
switch ( ctx->Computed ) { switch ( ctx->Computed ) {
case FNVinited+FNV256state: case FNVinited+FNV256state:
skipping to change at line 3584 skipping to change at line 3531
out[2*i] = ctx->Hash[i] >> 8; out[2*i] = ctx->Hash[i] >> 8;
out[2*i+1] = ctx->Hash[i]; out[2*i+1] = ctx->Hash[i];
ctx->Hash[i] = 0; ctx->Hash[i] = 0;
} }
ctx->Computed = FNVemptied+FNV256state; ctx->Computed = FNVemptied+FNV256state;
return fnvSuccess; return fnvSuccess;
} /* end FNV256result */ } /* end FNV256result */
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
//**************************************************************** //****************************************************************
// END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//**************************************************************** //****************************************************************
]]></sourcecode> ]]></sourcecode>
</section> </section>
<section> <section>
<name>FNV512 Code</name> <name>FNV512 Code</name>
<t>The header and C source for 512-bit FNV-1a providing a byte <t>The following code is the header and C source for 512-bit FNV-1a providing a byte
vector hash.</t> vector hash.</t>
<sourcecode type="C" markers="true" name="FNV512.h"> <sourcecode type="c" markers="true" name="FNV512.h"><![CDATA[
<![CDATA[
//************************* FNV512.h ***********************// //************************* FNV512.h ***********************//
//************** See RFC NNNN for details. *****************// //************** See RFC 9923 for details. *****************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#ifndef _FNV512_H_ #ifndef _FNV512_H_
#define _FNV512_H_ #define _FNV512_H_
/* /*
* Description: * Description:
* This file provides headers for the 512-bit version of * This file provides headers for the 512-bit version of
skipping to change at line 3652 skipping to change at line 3598
typedef struct FNV512context_s { typedef struct FNV512context_s {
int Computed; /* state */ int Computed; /* state */
uint16_t Hash[FNV512size/2]; uint16_t Hash[FNV512size/2];
} FNV512context; } FNV512context;
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
/* Function Prototypes: /* Function Prototypes:
* *
* FNV512string: hash a zero-terminated string not including * FNV512string: hash a zero-terminated string not including
* the terminating zero * the terminating zero
* FNV512stringBasis: also takes an offset_basis parameter * FNV512stringBasis: also takes an offset_basis parameter
* *
* FNV512block: hash a specified length byte vector * FNV512block: hash a byte vector of a specified length
* FNV512blockBasis: also takes an offset_basis parameter * FNV512blockBasis: also takes an offset_basis parameter
* *
* FNV512file: hash the contents of a file * FNV512file: hash the contents of a file
* FNV512fileBasis: also takes an offset_basis parameter * FNV512fileBasis: also takes an offset_basis parameter
* *
* FNV512init: initializes an FNV1024 context * FNV512init: initializes an FNV512 context
* FNV512initBasis: initializes an FNV1024 context with a * FNV512initBasis: initializes an FNV512 context with a
* provided 128-byte vector basis * provided 64-byte vector basis
* FNV512blockin: hash in a specified length byte vector * FNV512blockin: hash in a byte vector of a specified length
* FNV512stringin: hash in a zero-terminated string not * FNV512stringin: hash in a zero-terminated string not
* including the terminating zero * including the terminating zero
* FMNV512filein: hash in the contents of a file * FNV512filein: hash in the contents of a file
* FNV512result: returns the hash value * FNV512result: returns the hash value
* *
* Hash is returned as an array of 8-bit unsigned integers * Hash is returned as an array of 8-bit unsigned integers
*/ */
#ifdef __cplusplus #ifdef __cplusplus
extern "C" { extern "C" {
#endif #endif
/* FNV512 */ /* FNV512 */
skipping to change at line 3715 skipping to change at line 3661
extern int FNV512result ( FNV512context * const, extern int FNV512result ( FNV512context * const,
uint8_t out[FNV512size] ); uint8_t out[FNV512size] );
#ifdef __cplusplus #ifdef __cplusplus
} }
#endif #endif
#endif /* _FNV512_H_ */ #endif /* _FNV512_H_ */
]]></sourcecode> ]]></sourcecode>
<sourcecode type="C" markers="true" name="FNV512.c"> <sourcecode type="c" markers="true" name="FNV512.c"><![CDATA[
<![CDATA[
//**************************** FNV512.c **************************// //**************************** FNV512.c **************************//
//******************* See RFC NNNN for details *******************// //******************* See RFC 9923 for details. ******************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic /* This file implements the FNV (Fowler/Noll/Vo) non-cryptographic
* hash function FNV-1a for 512-bit hashes. * hash function FNV-1a for 512-bit hashes.
*/ */
#include <stdio.h> #include <stdio.h>
#include "fnv-private.h" #include "fnv-private.h"
#include "FNV512.h" #include "FNV512.h"
//***************************************************************** //*****************************************************************
// COMMON CODE FOR 64- AND 32-BIT INTEGER MODES // COMMON CODE FOR 64- AND 32-BIT INTEGER MODES
//***************************************************************** //*****************************************************************
/* FNV512 hash a zero-terminated string not including the zero /* FNV512: hash a zero-terminated string not including the zero
******************************************************************/ ******************************************************************/
int FNV512string ( const char *in, uint8_t out[FNV512size] ) { int FNV512string ( const char *in, uint8_t out[FNV512size] ) {
FNV512context ctx; FNV512context ctx;
int error; int error;
if ( (error = FNV512init ( &ctx )) ) if ( (error = FNV512init ( &ctx )) )
return error; return error;
if ( (error = FNV512stringin ( &ctx, in )) ) if ( (error = FNV512stringin ( &ctx, in )) )
return error; return error;
return FNV512result ( &ctx, out ); return FNV512result ( &ctx, out );
} /* end FNV512string */ } /* end FNV512string */
/* FNV512 hash a zero-terminated string not including the zero /* FNV512: hash a zero-terminated string not including the zero
* with a non-standard basis * with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV512stringBasis ( const char *in, int FNV512stringBasis ( const char *in,
uint8_t out[FNV512size], uint8_t out[FNV512size],
const uint8_t basis[FNV512size] ) { const uint8_t basis[FNV512size] ) {
FNV512context ctx; FNV512context ctx;
int error; int error;
if ( (error = FNV512initBasis ( &ctx, basis )) ) if ( (error = FNV512initBasis ( &ctx, basis )) )
return error; return error;
if ( (error = FNV512stringin ( &ctx, in )) ) if ( (error = FNV512stringin ( &ctx, in )) )
return error; return error;
return FNV512result ( &ctx, out ); return FNV512result ( &ctx, out );
} /* end FNV512stringBasis */ } /* end FNV512stringBasis */
/* FNV512 hash a counted block (64/32-bit) /* FNV512: hash a counted block (64/32-bit)
******************************************************************/ ******************************************************************/
int FNV512block ( const void *vin, int FNV512block ( const void *vin,
long int length, long int length,
uint8_t out[FNV512size] ) { uint8_t out[FNV512size] ) {
FNV512context ctx; FNV512context ctx;
int error; int error;
if ( (error = FNV512init ( &ctx )) ) if ( (error = FNV512init ( &ctx )) )
return error; return error;
if ( (error = FNV512blockin ( &ctx, vin, length)) ) if ( (error = FNV512blockin ( &ctx, vin, length)) )
return error; return error;
return FNV512result ( &ctx, out ); return FNV512result ( &ctx, out );
} /* end FNV512block */ } /* end FNV512block */
/* FNV512 hash a counted block with a non-standard basis (64/32-bit) /* FNV512: hash a counted block (64/32-bit)
* with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV512blockBasis ( const void *vin, int FNV512blockBasis ( const void *vin,
long int length, long int length,
uint8_t out[FNV512size], uint8_t out[FNV512size],
const uint8_t basis[FNV512size] ) { const uint8_t basis[FNV512size] ) {
FNV512context ctx; FNV512context ctx;
int error; int error;
if ( (error = FNV512initBasis ( &ctx, basis )) ) if ( (error = FNV512initBasis ( &ctx, basis )) )
return error; return error;
skipping to change at line 3868 skipping to change at line 3814
fclose(fp); fclose(fp);
return error; return error;
} }
error = ferror(fp); error = ferror(fp);
fclose(fp); fclose(fp);
if (error) return fnvBadParam; if (error) return fnvBadParam;
return fnvSuccess; return fnvSuccess;
} /* end FNV512filein */ } /* end FNV512filein */
//***************************************************************** //*****************************************************************
// START VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC // START VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC
//***************************************************************** //*****************************************************************
#ifdef FNV_64bitIntegers #ifdef FNV_64bitIntegers
/* 512-bit FNV_prime = 2^344 + 2^8 + 0x57 = /* 512-bit FNV_prime = 2^344 + 2^8 + 0x57 =
0x0000000000000000 0000000000000000 0x0000000000000000 0000000000000000
0000000001000000 0000000000000000 0000000001000000 0000000000000000
0000000000000000 0000000000000000 0000000000000000 0000000000000000
0000000000000000 0000000000000157 */ 0000000000000000 0000000000000157 */
#define FNV512primeX 0x0157 #define FNV512primeX 0x0157
#define FNV512shift 24 #define FNV512shift 24
skipping to change at line 4022 skipping to change at line 3968
out[4*i+1] = ctx->Hash[i] >> 16; out[4*i+1] = ctx->Hash[i] >> 16;
out[4*i+2] = ctx->Hash[i] >> 8; out[4*i+2] = ctx->Hash[i] >> 8;
out[4*i+3] = ctx->Hash[i]; out[4*i+3] = ctx->Hash[i];
ctx -> Hash[i] = 0; ctx -> Hash[i] = 0;
} }
ctx->Computed = FNVemptied+FNV512state; ctx->Computed = FNVemptied+FNV512state;
return fnvSuccess; return fnvSuccess;
} /* end FNV512result */ } /* end FNV512result */
//***************************************************************** //*****************************************************************
// END VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC // END VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC
//***************************************************************** //*****************************************************************
#else /* FNV_64bitIntegers */ #else /* FNV_64bitIntegers */
//***************************************************************** //*****************************************************************
// START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//***************************************************************** //*****************************************************************
/* 512-bit FNV_prime = 2^344 + 2^8 + 0x57 = /* 512-bit FNV_prime = 2^344 + 2^8 + 0x57 =
0x00000000 00000000 00000000 00000000 0x00000000 00000000 00000000 00000000
00000000 01000000 00000000 00000000 00000000 01000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000157 */ 00000000 00000000 00000000 00000157 */
#define FNV512primeX 0x0157 #define FNV512primeX 0x0157
#define FNV512shift 8 #define FNV512shift 8
skipping to change at line 4067 skipping to change at line 4013
} /* end FNV512init */ } /* end FNV512init */
/* initialize context with a provided 64-byte vector basis (32-bit) /* initialize context with a provided 64-byte vector basis (32-bit)
******************************************************************/ ******************************************************************/
int FNV512initBasis ( FNV512context * const ctx, int FNV512initBasis ( FNV512context * const ctx,
const uint8_t basis[FNV512size] ) { const uint8_t basis[FNV512size] ) {
if ( !ctx || !basis ) if ( !ctx || !basis )
return fnvNull; return fnvNull;
for ( int i=0; i < FNV512size/2; ++i ) { for ( int i=0; i < FNV512size/2; ++i ) {
uint32_t temp = *basis++; uint32_t temp = *basis++;
ctx->Hash[i] = ( temp<<8 ) + *basis++; ctx->Hash[i] = ( temp<<8 ) + *basis++;
} }
ctx->Computed = FNVinited+FNV512state; ctx->Computed = FNVinited+FNV512state;
return fnvSuccess; return fnvSuccess;
} /* end FNV512initBasis */ } /* end FNV512initBasis */
/* hash in a counted block (32-bit) /* hash in a counted block (32-bit)
******************************************************************/ ******************************************************************/
int FNV512blockin ( FNV512context * const ctx, int FNV512blockin ( FNV512context * const ctx,
const void *vin, const void *vin,
long int length ) { long int length ) {
skipping to change at line 4176 skipping to change at line 4122
out[2*i] = ctx->Hash[i] >> 8; out[2*i] = ctx->Hash[i] >> 8;
out[2*i+1] = ctx->Hash[i]; out[2*i+1] = ctx->Hash[i];
ctx->Hash[i] = 0; ctx->Hash[i] = 0;
} }
ctx->Computed = FNVemptied+FNV512state; ctx->Computed = FNVemptied+FNV512state;
return fnvSuccess; return fnvSuccess;
} /* end FNV512result */ } /* end FNV512result */
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
//***************************************************************** //*****************************************************************
// END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//***************************************************************** //*****************************************************************
]]></sourcecode> ]]></sourcecode>
</section> </section>
<section> <section>
<name>FNV1024 Code</name> <name>FNV1024 Code</name>
<t>The header and C source for 1024-bit FNV-1a providing a byte <t>The following code is the header and C source for 1024-bit FNV-1a providing a byte
vector hash.</t> vector hash.</t>
<sourcecode type="C" markers="true" name="FNV1024.h"> <sourcecode type="c" markers="true" name="FNV1024.h"><![CDATA[
<![CDATA[
//*********************** FNV1024.h ***********************// //*********************** FNV1024.h ***********************//
//************* See RFC NNNN for details. *****************// //************* See RFC 9923 for details. *****************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#ifndef _FNV1024_H_ #ifndef _FNV1024_H_
#define _FNV1024_H_ #define _FNV1024_H_
/* /*
* Description: * Description:
* This file provides headers for the 1024-bit version of * This file provides headers for the 1024-bit version of
skipping to change at line 4241 skipping to change at line 4186
#else #else
/* version if 64-bit integers NOT supported */ /* version if 64-bit integers NOT supported */
typedef struct FNV1024context_s { typedef struct FNV1024context_s {
int Computed; /* state */ int Computed; /* state */
uint16_t Hash[FNV1024size/2]; uint16_t Hash[FNV1024size/2];
} FNV1024context; } FNV1024context;
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
/* Function Prototypes: /* Function Prototypes:
* *
* FNV1024string: hash a zero-terminated string not including * FNV1024string: hash a zero-terminated string not including
* the terminating zero * the terminating zero
* FNV1024stringBasis: also takes an offset_basis parameter * FNV1024stringBasis: also takes an offset_basis parameter
* *
* FNV1024block: hash a specified length byte vector * FNV1024block: hash a byte vector of a specified length
* FNV1024blockBasis: also takes an offset_basis parameter * FNV1024blockBasis: also takes an offset_basis parameter
* *
* FNV1024file: hash the contents of a file * FNV1024file: hash the contents of a file
* FNV1024fileBasis: also takes an offset_basis parameter * FNV1024fileBasis: also takes an offset_basis parameter
* *
* FNV1024init: initializes an FNV1024 context * FNV1024init: initializes an FNV1024 context
* FNV1024initBasis: initializes an FNV1024 context with a * FNV1024initBasis: initializes an FNV1024 context with a
* provided 128-byte vector basis * provided 128-byte vector basis
* FNV1024blockin: hash in a specified length byte vector * FNV1024blockin: hash in a byte vector of a specified length
* FNV1024stringin: hash in a zero-terminated string not * FNV1024stringin: hash in a zero-terminated string not
* including the terminating zero * including the terminating zero
* FNV1024filein: hash in the contents of a file * FNV1024filein: hash in the contents of a file
* FNV1024result: returns the hash value * FNV1024result: returns the hash value
* *
* Hash is returned as an array of 8-bit unsigned integers * Hash is returned as an array of 8-bit unsigned integers
*/ */
#ifdef __cplusplus #ifdef __cplusplus
extern "C" { extern "C" {
skipping to change at line 4307 skipping to change at line 4252
extern int FNV1024result ( FNV1024context * const, extern int FNV1024result ( FNV1024context * const,
uint8_t out[FNV1024size] ); uint8_t out[FNV1024size] );
#ifdef __cplusplus #ifdef __cplusplus
} }
#endif #endif
#endif /* _FNV1024_H_ */ #endif /* _FNV1024_H_ */
]]></sourcecode> ]]></sourcecode>
<sourcecode type="C" markers="true" name="FNV1024.c"> <sourcecode type="c" markers="true" name="FNV1024.c"><![CDATA[
<![CDATA[
//************************** FNV1024.c **************************// //************************** FNV1024.c **************************//
//****************** See RFC NNNN for details *******************// //****************** See RFC 9923 for details. ******************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic /* This file implements the FNV (Fowler/Noll/Vo) non-cryptographic
* hash function FNV-1a for 1024-bit hashes. * hash function FNV-1a for 1024-bit hashes.
*/ */
#include <stdio.h> #include <stdio.h>
#include "fnv-private.h" #include "fnv-private.h"
#include "FNV1024.h" #include "FNV1024.h"
//***************************************************************** //*****************************************************************
// COMMON CODE FOR 64- AND 32-BIT INTEGER MODES // COMMON CODE FOR 64- AND 32-BIT INTEGER MODES
//***************************************************************** //*****************************************************************
/* FNV1024 hash a zero-terminated string not including the zero /* FNV1024: hash a zero-terminated string not including the zero
******************************************************************/ ******************************************************************/
int FNV1024string ( const char *in, uint8_t out[FNV1024size] ) { int FNV1024string ( const char *in, uint8_t out[FNV1024size] ) {
FNV1024context ctx; FNV1024context ctx;
int error; int error;
if ( (error = FNV1024init ( &ctx )) ) if ( (error = FNV1024init ( &ctx )) )
return error; return error;
if ( (error = FNV1024stringin ( &ctx, in )) ) if ( (error = FNV1024stringin ( &ctx, in )) )
return error; return error;
return FNV1024result ( &ctx, out ); return FNV1024result ( &ctx, out );
} /* end FNV1024string */ } /* end FNV1024string */
/* FNV1024 hash a zero-terminated string not including the zero /* FNV1024: hash a zero-terminated string not including the zero
* with a non-standard basis * with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV1024stringBasis ( const char *in, int FNV1024stringBasis ( const char *in,
uint8_t out[FNV1024size], uint8_t out[FNV1024size],
const uint8_t basis[FNV1024size] ) { const uint8_t basis[FNV1024size] ) {
FNV1024context ctx; FNV1024context ctx;
int error; int error;
if ( (error = FNV1024initBasis ( &ctx, basis )) ) if ( (error = FNV1024initBasis ( &ctx, basis )) )
return error; return error;
if ( (error = FNV1024stringin ( &ctx, in )) ) if ( (error = FNV1024stringin ( &ctx, in )) )
return error; return error;
return FNV1024result ( &ctx, out ); return FNV1024result ( &ctx, out );
} /* end FNV1024stringBasis */ } /* end FNV1024stringBasis */
/* FNV1024 hash a counted block (64/32-bit) /* FNV1024: hash a counted block (64/32-bit)
******************************************************************/ ******************************************************************/
int FNV1024block ( const void *vin, int FNV1024block ( const void *vin,
long int length, long int length,
uint8_t out[FNV1024size] ) { uint8_t out[FNV1024size] ) {
FNV1024context ctx; FNV1024context ctx;
int error; int error;
if ( (error = FNV1024init ( &ctx )) ) if ( (error = FNV1024init ( &ctx )) )
return error; return error;
if ( (error = FNV1024blockin ( &ctx, vin, length)) ) if ( (error = FNV1024blockin ( &ctx, vin, length)) )
return error; return error;
return FNV1024result ( &ctx, out ); return FNV1024result ( &ctx, out );
} /* end FNV1024block */ } /* end FNV1024block */
/* FNV1024 hash a counted block (64/32-bit) /* FNV1024: hash a counted block (64/32-bit)
* with a non-standard basis * with a non-standard basis
******************************************************************/ ******************************************************************/
int FNV1024blockBasis ( const void *vin, int FNV1024blockBasis ( const void *vin,
long int length, long int length,
uint8_t out[FNV1024size], uint8_t out[FNV1024size],
const uint8_t basis[FNV1024size] ) { const uint8_t basis[FNV1024size] ) {
FNV1024context ctx; FNV1024context ctx;
int error; int error;
if ( (error = FNV1024initBasis ( &ctx, basis )) ) if ( (error = FNV1024initBasis ( &ctx, basis )) )
skipping to change at line 4421 skipping to change at line 4365
FNV1024context e1024Context; FNV1024context e1024Context;
int error; int error;
if ( !out ) if ( !out )
return fnvNull; return fnvNull;
if ( (error = FNV1024initBasis (&e1024Context, basis)) ) if ( (error = FNV1024initBasis (&e1024Context, basis)) )
return error; return error;
if ( (error = FNV1024filein (&e1024Context, fname)) ) if ( (error = FNV1024filein (&e1024Context, fname)) )
return error; return error;
return FNV1024result ( &e1024Context, out ); return FNV1024result ( &e1024Context, out );
} /* end FMV1024fileBasis */ } /* end FNV1024fileBasis */
/* hash in the contents of a file /* hash in the contents of a file
******************************************************************/ ******************************************************************/
int FNV1024filein ( FNV1024context * const e1024Context, int FNV1024filein ( FNV1024context * const e1024Context,
const char *fname ) { const char *fname ) {
FILE *fp; FILE *fp;
long int i; long int i;
char buf[1024]; char buf[1024];
int error; int error;
skipping to change at line 4504 skipping to change at line 4448
if ( !ctx ) if ( !ctx )
return fnvNull; return fnvNull;
for ( int i=0; i<FNV1024size/4; ++i ) for ( int i=0; i<FNV1024size/4; ++i )
ctx->Hash[i] = FNV1024basis[i]; ctx->Hash[i] = FNV1024basis[i];
ctx->Computed = FNVinited+FNV1024state; ctx->Computed = FNVinited+FNV1024state;
return fnvSuccess; return fnvSuccess;
} /* end FNV1024init */ } /* end FNV1024init */
/* initialize context with a provided 128-byte vector basis (64-bit) /* initialize context with a provided 128-byte vector basis (64-bit)
******************************************************************/ *******************************************************************/
int FNV1024initBasis ( FNV1024context * const ctx, int FNV1024initBasis ( FNV1024context * const ctx,
const uint8_t basis[FNV1024size] ) { const uint8_t basis[FNV1024size] ) {
if ( !ctx || !basis ) if ( !ctx || !basis )
return fnvNull; return fnvNull;
for ( int i=0; i < FNV1024size/4; ++i ) { for ( int i=0; i < FNV1024size/4; ++i ) {
uint32_t temp = *basis++<<24; uint32_t temp = *basis++<<24;
temp += *basis++<<16; temp += *basis++<<16;
temp += *basis++<<8; temp += *basis++<<8;
ctx->Hash[i] = temp + *basis++; ctx->Hash[i] = temp + *basis++;
} }
skipping to change at line 4623 skipping to change at line 4567
out[4*i+1] = ctx->Hash[i] >> 16; out[4*i+1] = ctx->Hash[i] >> 16;
out[4*i+2] = ctx->Hash[i] >> 8; out[4*i+2] = ctx->Hash[i] >> 8;
out[4*i+3] = ctx->Hash[i]; out[4*i+3] = ctx->Hash[i];
ctx -> Hash[i] = 0; ctx -> Hash[i] = 0;
} }
ctx->Computed = FNVemptied+FNV1024state; ctx->Computed = FNVemptied+FNV1024state;
return fnvSuccess; return fnvSuccess;
} /* end FNV1024result */ } /* end FNV1024result */
//****************************************************************// //****************************************************************//
// END VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC // END VERSION FOR WHEN YOU HAVE 64-BIT ARITHMETIC
//***************************************************************// //****************************************************************//
#else /* FNV_64bitIntegers */ #else /* FNV_64bitIntegers */
//***************************************************************// //****************************************************************//
// START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//***************************************************************// //****************************************************************//
/* version for when you only have 32-bit arithmetic
******************************************************************/
/* /*
1024-bit FNV_prime = 2^680 + 2^8 + 0x8d = 1024-bit FNV_prime = 2^680 + 2^8 + 0x8d =
0x00000000 00000000 00000000 00000000 0x00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000100 00000000 00000000 00000000 00000100 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
skipping to change at line 4673 skipping to change at line 4614
if ( !ctx ) if ( !ctx )
return fnvNull; return fnvNull;
for ( int i=0; i<FNV1024size/2; ++i ) for ( int i=0; i<FNV1024size/2; ++i )
ctx->Hash[i] = FNV1024basis[i]; ctx->Hash[i] = FNV1024basis[i];
ctx->Computed = FNVinited+FNV1024state; ctx->Computed = FNVinited+FNV1024state;
return fnvSuccess; return fnvSuccess;
} /* end FNV1024init */ } /* end FNV1024init */
/* initialize context with a provided 128-byte vector basis (32-bit) /* initialize context with a provided 128-byte vector basis (32-bit)
******************************************************************/ *******************************************************************/
int FNV1024initBasis ( FNV1024context * const ctx, int FNV1024initBasis ( FNV1024context * const ctx,
const uint8_t basis[FNV1024size] ) { const uint8_t basis[FNV1024size] ) {
if ( !ctx || !basis ) if ( !ctx || !basis )
return fnvNull; return fnvNull;
for ( int i=0; i < FNV1024size/2; ++i ) { for ( int i=0; i < FNV1024size/2; ++i ) {
uint32_t temp = *basis++; uint32_t temp = *basis++;
ctx->Hash[i] = ( temp<<8 ) + *basis++; ctx->Hash[i] = ( temp<<8 ) + *basis++;
} }
ctx->Computed = FNVinited+FNV1024state; ctx->Computed = FNVinited+FNV1024state;
return fnvSuccess; return fnvSuccess;
} /* end FNV1024initBasis */ } /* end FNV1024initBasis */
/* hash in a counted block (32-bit) /* hash in a counted block (32-bit)
******************************************************************/ ******************************************************************/
int FNV1024blockin ( FNV1024context * const ctx, int FNV1024blockin ( FNV1024context * const ctx,
const void *vin, const void *vin,
long int length ) { long int length ) {
skipping to change at line 4789 skipping to change at line 4730
out[2*i] = ctx->Hash[i] >> 8; out[2*i] = ctx->Hash[i] >> 8;
out[2*i+1] = ctx->Hash[i]; out[2*i+1] = ctx->Hash[i];
ctx->Hash[i] = 0; ctx->Hash[i] = 0;
} }
ctx->Computed = FNVemptied+FNV1024state; ctx->Computed = FNVemptied+FNV1024state;
return fnvSuccess; return fnvSuccess;
} /* end FNV1024result */ } /* end FNV1024result */
#endif /* FNV_64bitIntegers */ #endif /* FNV_64bitIntegers */
//****************************************************************// //****************************************************************//
// END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC // END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC
//****************************************************************// //****************************************************************//
]]></sourcecode> ]]></sourcecode>
</section> </section>
</section> </section>
<section> <!-- 8.3 --> <section anchor="sec-8.3">
<name>FNV Test Code</name> <name>FNV Test Code</name>
<t>Below is source code for a test driver with a command line <t>Below is source code for a test driver with a command line
interface documented in Section 8.1.3. By default, with no command interface as documented in <xref target="sec-8.1.3"/>. By default, with no comma nd
line arguments, it runs tests of all FNV lengths.</t> line arguments, it runs tests of all FNV lengths.</t>
<sourcecode type="C" markers="true" name="main.c"> <sourcecode type="c" markers="true" name="main.c"><![CDATA[
<![CDATA[
//************************* Main.c **************************// //************************* Main.c **************************//
//*************** See RFC NNNN for details. *****************// //*************** See RFC 9923 for details. *****************//
/* Copyright (c) 2016, 2024, 2025 IETF Trust and the persons /* Copyright (c) 2016-2025 IETF Trust and the persons
* identified as authors of the code. All rights reserved. * identified as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution. * See fnv-private.h for terms of use and redistribution.
*/ */
#include <ctype.h> #include <ctype.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
#include <unistd.h> #include <unistd.h>
#include <errno.h> #include <errno.h>
/* To do a thorough test you need to run with /* To do a thorough test, you need to run with
* FNV_64bitIntegers defined and with it undefined * FNV_64bitIntegers defined and with it undefined
*/ */
#include "FNVconfig.h" #include "FNVconfig.h"
#include "fnv-private.h" #include "fnv-private.h"
#include "FNV32.h" #include "FNV32.h"
#include "FNV64.h" #include "FNV64.h"
#include "FNV128.h" #include "FNV128.h"
#include "FNV256.h" #include "FNV256.h"
#include "FNV512.h" #include "FNV512.h"
#include "FNV1024.h" #include "FNV1024.h"
/* global variables */ /* global variables */
char *funcName = "funcName not set?"; char *funcName = "funcName not set?";
const char *errteststring = "foo"; const char *errteststring = "foo";
int Terr = -1; /* Total errors */ int Terr = -1; /* Total errors */
int verbose = 0; /* verbose flag */ int verbose = 0; /* Verbose flag */
enum { FNV32selected = 0, FNV64selected, FNV128selected, enum { FNV32selected = 0, FNV64selected, FNV128selected,
FNV256selected, FNV512selected, FNV1024selected, FNV256selected, FNV512selected, FNV1024selected,
FNVnone = -1 } selected = FNVnone; FNVnone = -1 } selected = FNVnone;
#define NTestBytes 3 #define NTestBytes 3
const uint8_t errtestbytes[NTestBytes] = { (uint8_t)1, const uint8_t errtestbytes[NTestBytes] = { (uint8_t)1,
(uint8_t)2, (uint8_t)3 }; (uint8_t)2, (uint8_t)3 };
// initial teststring is null so initial result is offset_basis // initial teststring is null, so initial result is offset_basis
const char *teststring[] = { const char *teststring[] = {
"", "",
"a", "a",
"foobar", "foobar",
"Hello!\x01\xFF\xED" "Hello!\x01\xFF\xED"
}; };
#define NTstrings (sizeof(teststring)/sizeof(char *)) #define NTstrings (sizeof(teststring)/sizeof(char *))
// due to FNV-1 versus FNV1a, xor in final backslash separately // due to FNV-1 versus FNV1a, XOR in final backslash separately
const char BasisString[] = "chongo <Landon Curt Noll> /\\../"; const char BasisString[] = "chongo <Landon Curt Noll> /\\../";
FNV32context e32Context; FNV32context e32Context;
uint32_t eUint32 = 42; uint32_t eUint32 = 42;
#ifdef FNV_64bitIntegers #ifdef FNV_64bitIntegers
uint64_t eUint64 = 42; uint64_t eUint64 = 42;
#endif #endif
FNV64context e64Context; FNV64context e64Context;
FNV128context e128Context; FNV128context e128Context;
FNV256context e256Context; FNV256context e256Context;
FNV512context e512Context; FNV512context e512Context;
FNV1024context e1024Context; FNV1024context e1024Context;
uint8_t hash[FNV1024size]; /* largest size needed */ uint8_t hash[FNV1024size]; /* largest size needed */
uint8_t FakeBasis[FNV1024size]; uint8_t FakeBasis[FNV1024size];
uint8_t ZeroBasis[FNV1024size]; uint8_t ZeroBasis[FNV1024size];
char tempFileNameTemplate[] = "tmp.XXXXXXXXXX"; char tempFileNameTemplate[] = "tmp.XXXXXXXXXX";
const char *tempFileName = 0; const char *tempFileName = 0;
//**************************************************************** //****************************************************************
// local prototypes in alphabetic order // local prototypes in alphabetical order
//**************************************************************** //****************************************************************
void CommonTest ( void ); void CommonTest ( void );
void ErrTestReport ( void ); void ErrTestReport ( void );
int find_selected(const char *optarg); int find_selected(const char *optarg);
void HexPrint ( int count, const uint8_t *ptr ); void HexPrint ( int count, const uint8_t *ptr );
void TestAll ( void ); void TestAll ( void );
void Test32 ( void ); void Test32 ( void );
void Test64 ( void ); void Test64 ( void );
void Test128 ( void ); void Test128 ( void );
void Test256 ( void ); void Test256 ( void );
skipping to change at line 4943 skipping to change at line 4883
//**************************************************************** //****************************************************************
int main( int argc, const char **argv ) { int main( int argc, const char **argv ) {
int option; // command line option letter int option; // command line option letter
int i; int i;
uint16_t endianness = 5*256 + 11; uint16_t endianness = 5*256 + 11;
mkstemp(tempFileNameTemplate); mkstemp(tempFileNameTemplate);
tempFileName = tempFileNameTemplate; tempFileName = tempFileNameTemplate;
if ( ((uint8_t *)&endianness)[0] != 11 ) if ( ((uint8_t *)&endianness)[0] != 11 )
printf ("Coded for Little Endian but computer seems\n" printf ("Coded for little endian but computer seems\n"
" to be Big Endian! Multi-byte integer results\n" " to be big endian! Multi-byte integer results\n"
" may be incorrect!\n"); " may be incorrect!\n");
for ( i=0; i<FNV1024size; ++i ) {// initialize a couple of arrays for ( i=0; i<FNV1024size; ++i ) {// initialize a couple of arrays
ZeroBasis[i] = 0; ZeroBasis[i] = 0;
FakeBasis[i] = (uint8_t)i; FakeBasis[i] = (uint8_t)i;
} }
if ( argc == 1 ) { // if no arguments if ( argc == 1 ) { // if no arguments
TestAll(); TestAll();
if ( tempFileName ) if ( tempFileName )
unlink(tempFileName); unlink(tempFileName);
exit(0); exit(0);
} }
// process command line options // process command line options
// ***************************************************************** //*****************************************************************
while ((option = getopt(argc, (char *const *)argv, ":af:ht:u:v")) while ((option = getopt(argc, (char *const *)argv, ":af:ht:u:v"))
!= -1) { != -1) {
if ( verbose ) if ( verbose )
printf ( "Got option %c\n", option ); printf ( "Got option %c\n", option );
switch ( option ) { switch ( option ) {
case 'a': // run all tests case 'a': // run all tests
TestAll(); TestAll();
break; break;
case 'f': // followed by name of file to hash case 'f': // followed by name of file to hash
if ( selected == FNVnone ) { if ( selected == FNVnone ) {
printf ( "No hash size selected.\n" ); printf ( "No hash size selected.\n" );
break; break;
} }
printf ( "FNV-%i Hash of contents of file '%s':\n", printf ( "FNV-%i Hash of contents of file '%s':\n",
funcmap[selected].length, optarg ); funcmap[selected].length, optarg );
if ( funcmap[selected].Filefunc ( optarg, hash )) if ( funcmap[selected].Filefunc ( optarg, hash ))
printf ( "Hashing file '%s' fails: %s.\n", printf ( "Hashing file '%s' fails: %s.\n",
optarg, strerror(errno) ); optarg, strerror(errno) );
else else
HexPrint ( funcmap[selected].length/8, hash ); HexPrint ( funcmap[selected].length/8, hash );
printf ( "\n" ); printf ( "\n" );
break; break;
case 'h': // help case 'h': // help
usage( argv[0] ); usage( argv[0] );
break; break;
case 't': // follow by size of FNV to test, 0->all case 't': // followed by size of FNV to test, 0->all
selected = find_selected(optarg); selected = find_selected(optarg);
if (selected == FNVnone) if (selected == FNVnone)
printf ( "Bad argument to option -t\n" printf ( "Bad argument to option -t\n"
"Valid sizes are 32, 64, 128," "Valid sizes are 32, 64, 128,"
" 256, 512, and 1024\n"); " 256, 512, and 1024\n" );
else else
funcmap[selected].Testfunc(); // invoke test funcmap[selected].Testfunc(); // invoke test
break; break;
case 'u': // follow by size of FNV to use case 'u': // followed by size of FNV to use
selected = find_selected(optarg); selected = find_selected(optarg);
if ( selected == FNVnone ) if ( selected == FNVnone )
printf ( "Bad argument to option -u\n" printf ( "Bad argument to option -u\n"
"Valid sizes are 32, 64, 128," "Valid sizes are 32, 64, 128,"
"256, 512, and 1024\n" ); " 256, 512, and 1024\n" );
break; break;
case 'v': // toggle Verbose flag case 'v': // toggle Verbose flag
if ( (verbose ^= 1) ) { if ( (verbose ^= 1) ) {
printf ( "Verbose on.\n" ); printf ( "Verbose on.\n" );
#ifdef FNV_64bitIntegers #ifdef FNV_64bitIntegers
printf ("Has 64-bit Integers. "); printf ("Has 64-bit integers. ");
#else #else
printf ("Does not have 64-bit integers. "); printf ("Does not have 64-bit integers. ");
#endif #endif
// also tests the TestR function // also tests the TestR function
funcName = "Testing TestR"; funcName = "Testing TestR";
TestR ( "should fail", 1, 2 ); TestR ( "should fail", 1, 2 );
TestR ( "should not have failed", 3, 3 ); TestR ( "should not have failed", 3, 3 );
} }
else else
printf ( "Verbose off.\n" ); printf ( "Verbose off.\n" );
skipping to change at line 5029 skipping to change at line 4969
return 1; return 1;
} /* end switch */ } /* end switch */
} /* end while */ } /* end while */
if ( ( option == -1 ) && verbose ) if ( ( option == -1 ) && verbose )
printf ( "No more options.\n" ); printf ( "No more options.\n" );
// Through all the options, now, if a size is set, encrypt any // Through all the options, now, if a size is set, encrypt any
// other tokens on the command line // other tokens on the command line
//****************************************************** //******************************************************
for ( i = optind; i < argc; ++i ) { for ( i = optind; i < argc; ++i ) {
int rc; // return code int rc; // return code
if ( selected == FNVnone ) { if ( selected == FNVnone ) {
printf ( "No hash size selected.\n" ); printf ( "No hash size selected.\n" );
break; // out of for break; // out of for
} }
rc = funcmap[selected].Stringfunc(argv[i], hash); rc = funcmap[selected].Stringfunc(argv[i], hash);
if ( rc ) if ( rc )
printf ( "FNV-%i of '%s' returns error %i\n", printf ( "FNV-%i of '%s' returns error %i\n",
funcmap[selected].length, funcmap[selected].length,
argv[i], rc ); argv[i], rc );
skipping to change at line 5057 skipping to change at line 4997
if ( tempFileName ) if ( tempFileName )
unlink(tempFileName); unlink(tempFileName);
return 0; return 0;
} /* end main */ } /* end main */
/* Write to a temp file /* Write to a temp file
******************************************************************/ ******************************************************************/
const char *WriteTemp( const char *str, long int iLen ) { const char *WriteTemp( const char *str, long int iLen ) {
FILE *fp = fopen( tempFileName, "w" ); FILE *fp = fopen( tempFileName, "w" );
if (!fp) { if (!fp) {
printf( "Cannot open tempfile: %s: %s\n", printf ( "Cannot open tempfile: %s: %s\n",
tempFileName, strerror(errno) ); tempFileName, strerror(errno) );
return 0; return 0;
} }
long int ret = fwrite( str, 1, iLen, fp ); long int ret = fwrite( str, 1, iLen, fp );
fclose(fp); fclose(fp);
if ( ret != iLen ) { if ( ret != iLen ) {
printf( "Cannot write tempfile: %s: %s\n", printf ( "Cannot write tempfile: %s: %s\n",
tempFileName, strerror(errno) ); tempFileName, strerror(errno) );
return 0; return 0;
} }
return tempFileName; return tempFileName;
} }
//**************************************************************** //****************************************************************
// Test status return code // Test status return code
//**************************************************************** //****************************************************************
int TestR ( const char *name, int expect, int actual ) { int TestR ( const char *name, int expect, int actual ) {
if ( expect != actual ) { if ( expect != actual ) {
skipping to change at line 5087 skipping to change at line 5027
funcName, name, actual, expect ); funcName, name, actual, expect );
++Terr; /* increment error count */ ++Terr; /* increment error count */
} }
return actual; return actual;
} /* end TestR */ } /* end TestR */
//**************************************************************** //****************************************************************
// General byte vector return value test // General byte vector return value test
//**************************************************************** //****************************************************************
void TestNValue ( const char *subfunc, void TestNValue ( const char *subfunc,
const char *string, //usually what was hashed const char *string, // usually what was hashed
int N, int N,
const uint8_t was[N], const uint8_t was[N],
const uint8_t should[N] ) { const uint8_t should[N] ) {
if ( memcmp ( was, should, N) != 0 ) { if ( memcmp ( was, should, N ) != 0 ) {
++Terr; ++Terr;
printf ( "%s %s of '%s'", printf ( "%s %s of '%s'",
funcName, subfunc, string ); funcName, subfunc, string );
printf ( " computed " ); printf ( " computed " );
HexPrint ( N, was ); HexPrint ( N, was );
printf ( ", expected " ); printf ( ", expected " );
HexPrint ( N, should ); HexPrint ( N, should );
printf ( ".\n" ); printf ( ".\n" );
} }
else if ( verbose ) { else if ( verbose ) {
skipping to change at line 5197 skipping to change at line 5137
funcmap[selected].Blockfunc ( errtestbytes, 1, funcmap[selected].Blockfunc ( errtestbytes, 1,
(uint8_t *)0 ) ); (uint8_t *)0 ) );
TestR ( "blk1b", fnvNull, TestR ( "blk1b", fnvNull,
funcmap[selected].BlockBasisfunc ( (uint8_t *)0, 1, funcmap[selected].BlockBasisfunc ( (uint8_t *)0, 1,
hash, FakeBasis ) ); hash, FakeBasis ) );
TestR ( "blk2b", fnvBadParam, TestR ( "blk2b", fnvBadParam,
funcmap[selected].BlockBasisfunc ( errtestbytes, -1, funcmap[selected].BlockBasisfunc ( errtestbytes, -1,
hash, FakeBasis ) ); hash, FakeBasis ) );
TestR ( "blk3b", fnvNull, TestR ( "blk3b", fnvNull,
funcmap[selected].BlockBasisfunc ( errtestbytes, 1, funcmap[selected].BlockBasisfunc ( errtestbytes, 1,
(uint8_t *)0 , FakeBasis ) ); (uint8_t *)0, FakeBasis ) );
TestR ( "blk4b", fnvNull, TestR ( "blk4b", fnvNull,
funcmap[selected].BlockBasisfunc ( errtestbytes, 1, funcmap[selected].BlockBasisfunc ( errtestbytes, 1,
hash, (uint8_t *)0 ) ); hash, (uint8_t *)0 ) );
TestR ( "file1", fnvNull, TestR ( "file1", fnvNull,
funcmap[selected].Filefunc ( (char *)0, hash )); funcmap[selected].Filefunc ( (char *)0, hash ) );
TestR ( "file2", fnvNull, TestR ( "file2", fnvNull,
funcmap[selected].Filefunc ( "foo.txt", (uint8_t *)0 )); funcmap[selected].Filefunc ( "foo.txt", (uint8_t *)0 ) );
TestR ( "file1b", fnvNull, TestR ( "file1b", fnvNull,
funcmap[selected].FileBasisfunc ( (char *)0, hash, funcmap[selected].FileBasisfunc ( (char *)0, hash,
FakeBasis )); FakeBasis ) );
TestR ( "file2b", fnvNull, TestR ( "file2b", fnvNull,
funcmap[selected].FileBasisfunc ( "foo.txt", (uint8_t *)0, funcmap[selected].FileBasisfunc ( "foo.txt", (uint8_t *)0,
FakeBasis )); FakeBasis ) );
TestR ( "file3b", fnvNull, TestR ( "file3b", fnvNull,
funcmap[selected].FileBasisfunc ( "foo.txt", hash, funcmap[selected].FileBasisfunc ( "foo.txt", hash,
(uint8_t *)0 )); (uint8_t *)0 ) );
} /* end CommonTest */ } /* end CommonTest */
//**************************************************************** //****************************************************************
// Print command line help // Print command line help
//**************************************************************** //****************************************************************
void usage( const char *argv0 ) { void usage( const char *argv0 ) {
printf ( printf (
"%s [-a] [-t nnn] [-u nnn] [-v] [-f filename] [token ...]\n" "%s [-a] [-t nnn] [-u nnn] [-v] [-f filename] [token ...]\n"
" -a = run all tests\n" " -a = run all tests\n"
" -f filename = hash file contents\n" " -f filename = hash file contents\n"
skipping to change at line 5237 skipping to change at line 5177
" -v = toggle Verbose flag\n" " -v = toggle Verbose flag\n"
" Each token is hashed.\n", argv0 ); " Each token is hashed.\n", argv0 );
} /* end usage */ } /* end usage */
//**************************************************************** //****************************************************************
// Test Macros // Test Macros
//**************************************************************** //****************************************************************
// test for return values // test for return values
//************************ //************************
#define TestInit(INIT,CTX,CTXT) \ #define TestInit(INIT,CTX,CTXT) \
TestR ( "init1", fnvSuccess, INIT ( &CTX ) ); \ TestR ( "init1", fnvSuccess, INIT ( &CTX ) ); \
TestR ( "init2", fnvNull, INIT ( (CTXT *)0 ) ); TestR ( "init2", fnvNull, INIT ( (CTXT *)0 ) );
#define TestInitBasis(INITB,CTX,CTXT) \ #define TestInitBasis(INITB,CTX,CTXT) \
TestR ( "initB1", fnvSuccess, INITB (&CTX, FakeBasis )); \ TestR ( "initB1", fnvSuccess, INITB (&CTX, FakeBasis ) );
TestR ( "initB2", fnvNull, INITB ( (CTXT *)0, hash ) ); \ TestR ( "initB2", fnvNull, INITB ( (CTXT *)0, hash ) ); \
TestR ( "initB3", fnvNull, INITB ( &CTX, (uint8_t *)0 )); TestR ( "initB3", fnvNull, INITB ( &CTX, (uint8_t *)0 ) );
#define TestBlockin(BLKIN,CTX,CTXT) \ #define TestBlockin(BLKIN,CTX,CTXT) \
TestR ( "blockin1", fnvNull, \ TestR ( "blockin1", fnvNull, \
BLKIN ( (CTXT *)0, errtestbytes, NTestBytes ) ); \ BLKIN ( (CTXT *)0, errtestbytes, NTestBytes ) ); \
TestR ( "blockin2", fnvNull, \ TestR ( "blockin2", fnvNull, \
BLKIN ( &CTX, (uint8_t *)0, NTestBytes ) ); \ BLKIN ( &CTX, (uint8_t *)0, NTestBytes ) ); \
TestR ( "blockin3", fnvBadParam, \ TestR ( "blockin3", fnvBadParam, \
BLKIN ( &CTX, errtestbytes, -1 ) ); \ BLKIN ( &CTX, errtestbytes, -1 ) ); \
TestR ( "blockin4", fnvStateError, \ TestR ( "blockin4", fnvStateError, \
BLKIN ( &CTX, errtestbytes, NTestBytes ) ); BLKIN ( &CTX, errtestbytes, NTestBytes ) );
#define TestStringin(STRIN,CTX,CTXT) \ #define TestStringin(STRIN,CTX,CTXT) \
TestR ( "stringin1", fnvNull, \ TestR ( "stringin1", fnvNull, \
STRIN ( (CTXT *)0, errteststring ) ); \ STRIN ( (CTXT *)0, errteststring ) ); \
TestR ( "stringin2", fnvNull, STRIN ( &CTX, (char *)0 ) ); \ TestR ( "stringin2", fnvNull, STRIN ( &CTX, (char *)0 ) ); \
TestR ( "stringin3", fnvStateError, \ TestR ( "stringin3", fnvStateError, \
STRIN ( &CTX, errteststring ) ); STRIN ( &CTX, errteststring ) );
#define TestFilein(FLIN,CTX,CTXT) \ #define TestFilein(FLIN,CTX,CTXT) \
TestR ( "file1", fnvNull, FLIN ( (CTXT *)0, errteststring ) );\ TestR ( "file1", fnvNull, FLIN ( (CTXT *)0, errteststring ) ); \
TestR ( "file2", fnvNull, FLIN ( &CTX, (char *)0 ) ); \ TestR ( "file2", fnvNull, FLIN ( &CTX, (char *)0 ) ); \
TestR ( "file3", fnvStateError, \ TestR ( "file3", fnvStateError, \
FLIN ( &CTX, errteststring ) ); FLIN ( &CTX, errteststring ) );
#define TestResult(RSLT,CTX,CTXT) \ #define TestResult(RSLT,CTX,CTXT) \
TestR ( "result1", fnvNull, RSLT ( (CTXT *)0, hash ) ); \ TestR ( "result1", fnvNull, RSLT ( (CTXT *)0, hash ) ); \
TestR ( "result2", fnvNull, RSLT ( &CTX, (uint8_t *)0 ) ); \ TestR ( "result2", fnvNull, RSLT ( &CTX, (uint8_t *)0 ) ); \
TestR ( "result3", fnvStateError, \ TestR ( "result3", fnvStateError, \
FNV128result ( &e128Context, hash ) ); FNV128result ( &e128Context, hash ) );
// test return values for INT versions including non-std basis // test return values for INT versions including non-std basis
//************************************************************* //*************************************************************
#define TestINT(STRINT,STRINTB,BLKINT,BLKINTB,INITINTB, \ #define TestINT(STRINT,STRINTB,BLKINT,BLKINTB,INITINTB, \
INTV,INTVT,ctxT) \ INTV,INTVT,ctxT) \
TestR ( "string1i", fnvNull, STRINT ( (char *)0, &INTV ) ); \ TestR ( "string1i", fnvNull, STRINT ( (char *)0, &INTV ) ); \
TestR ( "string2i", fnvNull, \ TestR ( "string2i", fnvNull, \
STRINT ( errteststring, (INTVT *)0 ) ); \ STRINT ( errteststring, (INTVT *)0 ) ); \
TestR ("string3i", fnvNull, STRINTB ((char *)0, &INTV, INTV));\ TestR ( "string3i", fnvNull, STRINTB ((char *)0, &INTV, INTV) );\
TestR ( "string4i", fnvNull, \ TestR ( "string4i", fnvNull, \
STRINTB (errteststring, (INTVT *)0, INTV)); \ STRINTB (errteststring, (INTVT *)0, INTV) ); \
TestR ("block1i", fnvNull, BLKINT ( (uint8_t *)0, 1, &INTV ));\ TestR ( "block1i", fnvNull, BLKINT ( (uint8_t *)0, 1, &INTV ) );\
TestR ( "block2i", fnvBadParam, \ TestR ( "block2i", fnvBadParam, \
BLKINT ( errtestbytes, -1, &INTV ) ); \ BLKINT ( errtestbytes, -1, &INTV ) ); \
TestR ( "block3i", fnvNull, \ TestR ( "block3i", fnvNull, \
BLKINT ( errtestbytes, 1, (INTVT *)0 ) ); \ BLKINT ( errtestbytes, 1, (INTVT *)0 ) ); \
TestR ( "block4i", fnvNull, \ TestR ( "block4i", fnvNull, \
BLKINTB ( (uint8_t *)0, 1, &INTV, INTV ) ); \ BLKINTB ( (uint8_t *)0, 1, &INTV, INTV ) ); \
TestR ( "block5i", fnvBadParam, \ TestR ( "block5i", fnvBadParam, \
BLKINTB ( errtestbytes, -1, &INTV, INTV ) ); \ BLKINTB ( errtestbytes, -1, &INTV, INTV ) ); \
TestR ( "block6i", fnvNull, \ TestR ( "block6i", fnvNull, \
BLKINTB ( errtestbytes, 1, (INTVT *)0, INTV ) ); \ BLKINTB ( errtestbytes, 1, (INTVT *)0, INTV ) ); \
TestR ("initBasis1i", fnvNull, INITINTB ( (ctxT *)0, INTV )); TestR ( "initBasis1i", fnvNull, INITINTB ( (ctxT *)0, INTV ) );
#define TestINTrf(RSLTINT,FILEINT,FILEINTB, \ #define TestINTrf(RSLTINT,FILEINT,FILEINTB, \
ctx,ctxT,INTV,INTVT) \ ctx,ctxT,INTV,INTVT) \
TestR ( "result1i", fnvNull, RSLTINT ( (ctxT *)0, &INTV ) ); \ TestR ( "result1i", fnvNull, RSLTINT ( (ctxT *)0, &INTV ) ); \
TestR ( "result2i", fnvNull, RSLTINT ( &ctx, (INTVT *)0 ) ); \ TestR ( "result2i", fnvNull, RSLTINT ( &ctx, (INTVT *)0 ) ); \
TestR ( "result3i", fnvStateError, RSLTINT ( &ctx, &INTV ) );\ TestR ( "result3i", fnvStateError, RSLTINT ( &ctx, &INTV ) ); \
TestR ( "file1i", fnvNull, FILEINT ( (char *)0, &INTV )); \ TestR ( "file1i", fnvNull, FILEINT ( (char *)0, &INTV ) ); \
TestR ( "file2i", fnvNull, FILEINT ( "foo.txt", (INTVT *)0 ));\ TestR ( "file2i", fnvNull, FILEINT ( "foo.txt", (INTVT *)0 ) ); \
TestR ("file3i", fnvNull, FILEINTB ( (char *)0, &INTV, INTV));\ TestR ( "file3i", fnvNull, FILEINTB ( (char *)0, &INTV, INTV) );\
TestR ( "file4i", fnvNull, \ TestR ( "file4i", fnvNull, \
FILEINTB ( "foo.txt", (INTVT *)0, INTV )); FILEINTB ( "foo.txt", (INTVT *)0, INTV ) );
// test to calculate standard basis from basis zero FNV-1 // test to calculate standard basis from basis zero FNV-1
// depends on zero basis making the initial multiply a no-op // depends on zero basis making the initial multiply a no-op
//***************************** //*****************************
#define BasisZero(STRING,SIZ,VALUE) \ #define BasisZero(STRING,SIZ,VALUE) \
err = TestR ( "fnv0s", fnvSuccess, \ err = TestR ( "fnv0s", fnvSuccess, \
STRING ( BasisString, hash, ZeroBasis ) ); \ STRING ( BasisString, hash, ZeroBasis ) ); \
if ( err == fnvSuccess ) { \ if ( err == fnvSuccess ) { \
hash[SIZ-1] ^= '\\'; \ hash[SIZ-1] ^= '\\'; \
TestNValue ("fnv0sv", BasisString, SIZ, hash, VALUE[0]); \ TestNValue ( "fnv0sv", BasisString, SIZ, hash, VALUE[0] ); \
} }
#define BasisINTZero(STRINT,SIZ,VALUE,INTV,INTVT) \ #define BasisINTZero(STRINT,SIZ,VALUE,INTV,INTVT) \
err = TestR ( "fnv0s", fnvSuccess, \ err = TestR ( "fnv0s", fnvSuccess, \
STRINT ( BasisString, &INTV, (INTVT) 0 ) ); \ STRINT ( BasisString, &INTV, (INTVT) 0 ) ); \
if ( err == fnvSuccess ) { \ if ( err == fnvSuccess ) { \
INTV ^= '\\'; \ INTV ^= '\\'; \
TestNValue ("fnv0svi", BasisString, SIZ, \ TestNValue ( "fnv0svi", BasisString, SIZ, \
(uint8_t *)&INTV, (uint8_t *)&VALUE[0]); \ (uint8_t *)&INTV, (uint8_t *)&VALUE[0] ); \
} }
// test for return hash values // test for return hash values
//***************************** //*****************************
#define TestSTRBLKHash(STR,BLK,SVAL,BVAL,SZ) \ #define TestSTRBLKHash(STR,BLK,SVAL,BVAL,SZ) \
if ( TestR ( "stringa", fnvSuccess, \ if ( TestR ( "stringa", fnvSuccess, \
STR ( teststring[i], hash ) ) ) \ STR ( teststring[i], hash ) ) ) \
printf ( " Index = %i\n", i ); \ printf ( " Index = %i\n", i ); \
else \ else \
TestNValue ( "stringb", teststring[i], SZ, \ TestNValue ( "stringb", teststring[i], SZ, \
hash, (uint8_t *)&SVAL[i] ); \ hash, (uint8_t *)&SVAL[i] ); \
if ( TestR ( "blocka", fnvSuccess, BLK ( teststring[i], \ if ( TestR ( "blocka", fnvSuccess, BLK ( teststring[i], \
(long int)(strlen(teststring[i])+1), hash ) ) ) \ (long int)(strlen(teststring[i])+1), hash ) ) ) \
printf ( " Index = %i\n", i ); \ printf ( " Index = %i\n", i ); \
else \ else \
TestNValue ( "blockb", teststring[i], SZ, \ TestNValue ( "blockb", teststring[i], SZ, \
hash, (uint8_t *)&BVAL[i] ); hash, (uint8_t *)&BVAL[i] );
// Test incremental functions // Test incremental functions
//**************************** //****************************
#define IncrHash(INIT,CTX,BLK,RSLT,INITB,STR,SZ,SVAL) \ #define IncrHash(INIT,CTX,BLK,RSLT,INITB,STR,SZ,SVAL) \
err = TestR ( "inita", fnvSuccess, INIT ( &CTX ) ); \ err = TestR ( "inita", fnvSuccess, INIT ( &CTX ) ); \
if ( err ) break; \ if ( err ) break; \
iLen = strlen ( teststring[i] ); \ iLen = strlen ( teststring[i] ); \
err = TestR ("blockina", fnvSuccess, \ err = TestR ( "blockina", fnvSuccess, \
BLK ( &CTX, (uint8_t *)teststring[i], iLen/2 )); \ BLK ( &CTX, (uint8_t *)teststring[i], iLen/2 ) ); \
if ( err ) break; \ if ( err ) break; \
if ( i & 1 ) { \ if ( i & 1 ) { \
err = TestR ("basisra", fnvSuccess, RSLT ( &CTX, hash )); \ err = TestR ( "basisra", fnvSuccess, RSLT ( &CTX, hash ) ); \
if ( err ) break; \ if ( err ) break; \
err = TestR ("basisia", fnvSuccess, INITB ( &CTX, hash ));\ err = TestR ( "basisia", fnvSuccess, INITB ( &CTX, hash ) );\
if ( err ) break; \ if ( err ) break; \
} \ } \
err = TestR ( "stringina", fnvSuccess, STR ( &CTX, \ err = TestR ( "stringina", fnvSuccess, STR ( &CTX, \
teststring[i] + iLen/2 ) ); \ teststring[i] + iLen/2 ) ); \
if ( err ) break; \ if ( err ) break; \
err = TestR ( "resulta", fnvSuccess, RSLT ( &CTX, hash ) ); \ err = TestR ( "resulta", fnvSuccess, RSLT ( &CTX, hash ) ); \
if ( err ) break; \ if ( err ) break; \
TestNValue ( "incrementala", teststring[i], SZ, \ TestNValue ( "incrementala", teststring[i], SZ, \
hash, (uint8_t *)&SVAL[i] ); hash, (uint8_t *)&SVAL[i] );
// test file hash // test file hash
//***************************** //*****************************
#define TestFILEHash(FILE,BVAL,SZ) \ #define TestFILEHash(FILE,BVAL,SZ) \
err = TestR ( "fileafh", fnvSuccess, \ err = TestR ( "fileafh", fnvSuccess, \
FILE ( WriteTemp(teststring[i], iLen), \ FILE ( WriteTemp(teststring[i], iLen), \
hash ) ); \ hash ) ); \
if ( err ) break; \ if ( err ) break; \
TestNValue ( "filebfh", teststring[i], SZ, hash, \ TestNValue ( "filebfh", teststring[i], SZ, hash, \
(uint8_t *)&BVAL[i] ); (uint8_t *)&BVAL[i] );
//**************************************************************** //****************************************************************
// FNV32 Test // FNV32 Test
//**************************************************************** //****************************************************************
void Test32 ( void ) { void Test32 ( void ) {
long int iLen; long int iLen;
uint32_t FNV32svalues[NTstrings] = { uint32_t FNV32svalues[NTstrings] = {
0x811c9dc5, 0xe40c292c, 0xbf9cf968, 0xfd9d3881 }; 0x811c9dc5, 0xe40c292c, 0xbf9cf968, 0xfd9d3881 };
uint32_t FNV32bvalues[NTstrings] = { uint32_t FNV32bvalues[NTstrings] = {
skipping to change at line 5409 skipping to change at line 5349
e32Context.Computed = FNVclobber+FNV32state; e32Context.Computed = FNVclobber+FNV32state;
TestBlockin (FNV32blockin, e32Context, FNV32context) TestBlockin (FNV32blockin, e32Context, FNV32context)
TestStringin (FNV32stringin, e32Context, FNV32context) TestStringin (FNV32stringin, e32Context, FNV32context)
TestFilein (FNV32filein, e32Context, FNV32context) TestFilein (FNV32filein, e32Context, FNV32context)
TestResult (FNV32result, e32Context, FNV32context) TestResult (FNV32result, e32Context, FNV32context)
TestINTrf(FNV32INTresult,FNV32INTfile,FNV32INTfileBasis, TestINTrf(FNV32INTresult,FNV32INTfile,FNV32INTfileBasis,
e32Context,FNV32context,eUint32,uint32_t) e32Context,FNV32context,eUint32,uint32_t)
ErrTestReport (); ErrTestReport ();
Terr = 0; Terr = 0;
err = TestR ( "fnv0s", fnvSuccess, err = TestR ( "fnv0s", fnvSuccess,
FNV32stringBasis ( BasisString, hash, ZeroBasis )); FNV32stringBasis ( BasisString, hash, ZeroBasis ) );
if ( err == fnvSuccess ) { if ( err == fnvSuccess ) {
hash[0] ^= '\\'; hash[0] ^= '\\';
TestNValue ( "fnv0sv32", BasisString, FNV32size, TestNValue ( "fnv0sv32", BasisString, FNV32size,
hash, (uint8_t *)&FNV32svalues[0]); hash, (uint8_t *)&FNV32svalues[0]);
} }
BasisINTZero (FNV32INTstringBasis,FNV32size,FNV32svalues, \ BasisINTZero (FNV32INTstringBasis,FNV32size,FNV32svalues, \
eUint32,uint32_t) eUint32,uint32_t)
for ( i = 0; i < NTstrings; ++i ) { for ( i = 0; i < NTstrings; ++i ) {
/* test actual results int */ /* test actual results int */
err = TestR ( "stringai", fnvSuccess, err = TestR ( "stringai", fnvSuccess,
skipping to change at line 5481 skipping to change at line 5421
FNV32stringin ( &e32Context, FNV32stringin ( &e32Context,
teststring[i] + iLen/2 ) ); teststring[i] + iLen/2 ) );
if ( err ) break; if ( err ) break;
err = TestR ( "resultab", fnvSuccess, err = TestR ( "resultab", fnvSuccess,
FNV32result ( &e32Context, hash ) ); FNV32result ( &e32Context, hash ) );
if ( err ) break; if ( err ) break;
TestNValue ( "incrementala", teststring[i], FNV32size, TestNValue ( "incrementala", teststring[i], FNV32size,
hash, (uint8_t *)&FNV32svalues[i] ); hash, (uint8_t *)&FNV32svalues[i] );
/* now try testing file hash int */ /* now try testing file hash int */
err = TestR ( "fileafi", fnvSuccess, err = TestR ( "fileafi", fnvSuccess,
FNV32INTfile ( FNV32INTfile ( WriteTemp(teststring[i], iLen),
WriteTemp(teststring[i], iLen), &eUint32 ) );
&eUint32 )
);
if ( err ) break; if ( err ) break;
TestNValue ( "filebfi", teststring[i], FNV32size, TestNValue ( "filebfi", teststring[i], FNV32size,
(uint8_t *)&eUint32, (uint8_t *)&eUint32,
(uint8_t *)&FNV32svalues[i] ); (uint8_t *)&FNV32svalues[i] );
/* now try testing file hash byte */ /* now try testing file hash byte */
TestFILEHash ( FNV32file, FNV32svalues, FNV32size ) TestFILEHash ( FNV32file, FNV32svalues, FNV32size )
} // end for i } // end for i
ValueTestReport (); ValueTestReport ();
} /* end Test32 */ } /* end Test32 */
skipping to change at line 5532 skipping to change at line 5470
TestBlockin (FNV64blockin, e64Context, FNV64context) TestBlockin (FNV64blockin, e64Context, FNV64context)
TestStringin (FNV64stringin, e64Context, FNV64context) TestStringin (FNV64stringin, e64Context, FNV64context)
TestFilein (FNV64filein, e64Context, FNV64context) TestFilein (FNV64filein, e64Context, FNV64context)
TestResult (FNV64result, e64Context, FNV64context) TestResult (FNV64result, e64Context, FNV64context)
TestINTrf(FNV64INTresult,FNV64INTfile,FNV64INTfileBasis, TestINTrf(FNV64INTresult,FNV64INTfile,FNV64INTfileBasis,
e64Context,FNV64context,eUint64,uint64_t) e64Context,FNV64context,eUint64,uint64_t)
ErrTestReport (); ErrTestReport ();
/* test actual results int */ /* test actual results int */
Terr = 0; Terr = 0;
err = TestR ( "fnv0s", fnvSuccess, err = TestR ( "fnv0s", fnvSuccess,
FNV64stringBasis ( BasisString, hash, ZeroBasis )); FNV64stringBasis ( BasisString, hash, ZeroBasis ) );
if ( err == fnvSuccess ) { if ( err == fnvSuccess ) {
hash[0] ^= '\\'; hash[0] ^= '\\';
TestNValue ( "fnv0sv64", BasisString, FNV64size, TestNValue ( "fnv0sv64", BasisString, FNV64size,
hash, (uint8_t *)&FNV64svalues[0]); hash, (uint8_t *)&FNV64svalues[0]);
} }
BasisINTZero (FNV64INTstringBasis,FNV64size,FNV64svalues, \ BasisINTZero (FNV64INTstringBasis,FNV64size,FNV64svalues, \
eUint64,uint64_t) eUint64,uint64_t)
for ( i = 0; i < NTstrings; ++i ) { for ( i = 0; i < NTstrings; ++i ) {
/* test actual results int */ /* test actual results int */
err = TestR ( "stringai", fnvSuccess, err = TestR ( "stringai", fnvSuccess,
skipping to change at line 5604 skipping to change at line 5542
FNV64stringin ( &e64Context, FNV64stringin ( &e64Context,
teststring[i] + iLen/2 ) ); teststring[i] + iLen/2 ) );
if ( err ) break; if ( err ) break;
err = TestR ( "resultab", fnvSuccess, err = TestR ( "resultab", fnvSuccess,
FNV64result ( &e64Context, hash ) ); FNV64result ( &e64Context, hash ) );
if ( err ) break; if ( err ) break;
TestNValue ( "incrementala", teststring[i], FNV64size, TestNValue ( "incrementala", teststring[i], FNV64size,
hash, (uint8_t *)&FNV64svalues[i] ); hash, (uint8_t *)&FNV64svalues[i] );
/* now try testing file int */ /* now try testing file int */
err = TestR ( "fileafi", fnvSuccess, err = TestR ( "fileafi", fnvSuccess,
FNV64INTfile ( FNV64INTfile ( WriteTemp(teststring[i], iLen),
WriteTemp(teststring[i], iLen), &eUint64 ) );
&eUint64 )
);
if ( err ) break; if ( err ) break;
TestNValue ( "filebfi", teststring[i], FNV64size, TestNValue ( "filebfi", teststring[i], FNV64size,
(uint8_t *)&eUint64, (uint8_t *)&eUint64,
(uint8_t *)&FNV64svalues[i] ); (uint8_t *)&FNV64svalues[i] );
/* now try testing file hash */ /* now try testing file hash */
TestFILEHash(FNV64file,FNV64svalues,FNV64size) TestFILEHash(FNV64file,FNV64svalues,FNV64size)
} }
ValueTestReport (); ValueTestReport ();
} /* end Test64 */ } /* end Test64 */
skipping to change at line 6061 skipping to change at line 5997
/* now try testing file hash */ /* now try testing file hash */
TestFILEHash(FNV1024file,FNV1024svalues,FNV1024size) TestFILEHash(FNV1024file,FNV1024svalues,FNV1024size)
} }
ValueTestReport (); ValueTestReport ();
} /* end Test1024 */ } /* end Test1024 */
]]> ]]>
</sourcecode> </sourcecode>
</section> </section>
<section> <!-- 8.4 --> <section anchor="sec-8.4">
<name>Makefile</name> <name>Makefile</name>
<t>Below is a simple makefile to produce and run the test program or <t>Below is a simple makefile to produce and run the test program or
to provide a library with all the FNV functions supplied in it.</t> to provide a library with all the FNV functions supplied in it.</t>
<t>WARNING: When actually using the following as a makefile, the <t>WARNING: When actually using the following as a makefile, the
five character sequence "&lt;TAB>" must be changed to a tab (0x09) five-character sequence "&lt;TAB>" must be changed to a tab (0x09)
character!</t> character!</t>
<sourcecode type="makefile" markers="true" name="makefile"> <sourcecode type="makefile" markers="true" name="makefile"><![CDATA[
# Makefile for fnv # Makefile for fnv
# If you extract this file from RFC NNNN, the five character sequence # If you extract this file from RFC 9923, the five-character sequence
# &lt;TAB> below must be replace with a tab (0x09) character. # <TAB> below must be replaced with a tab (0x09) character.
explanation: explanation:
&lt;TAB>@echo Choose one of the following make targets: <TAB>@echo Choose one of the following make targets:
&lt;TAB>@echo make FNVhash -- test program <TAB>@echo make FNVhash -- test program
&lt;TAB>@echo make libfnv.a -- library you can use <TAB>@echo make libfnv.a -- library you can use
&lt;TAB>@echo make clean -- removes all of the built targets <TAB>@echo make clean -- removes all of the built targets
SRC=FNV1024.c FNV128.c FNV256.c FNV32.c FNV512.c FNV64.c SRC=FNV32.c FNV64.c FNV128.c FNV256.c FNV512.c FNV1024.c
HDR=FNV32.h FNV64.h FNV128.h FNV256.h FNV512.h FNV1024.h \ HDR=FNV32.h FNV64.h FNV128.h FNV256.h FNV512.h FNV1024.h \
<TAB>FNVErrorCodes.h FNVconfig.h fnv-private.h <TAB>FNVconfig.h FNVErrorCodes.h fnv-private.h
OBJ=$(SRC:.c=.o) OBJ=$(SRC:.c=.o)
CFLAGS=-Wall CFLAGS=-Wall
AR=ar AR=ar
ARFLAGS= rcs ARFLAGS= rcs
FNVhash: libfnv.a main.c FNVhash: libfnv.a main.c
&lt;TAB>$(CC) $(CFLAGS) -o FNVhash main.c libfnv.a <TAB>$(CC) $(CFLAGS) -o FNVhash main.c libfnv.a
libfnv.a: $(SRC) $(HDR) libfnv.a: $(SRC) $(HDR)
&lt;TAB>rm -f libfnv.a *.o <TAB>rm -f libfnv.a *.o
&lt;TAB>$(CC) $(CFLAGS) -c $(SRC) <TAB>$(CC) $(CFLAGS) -c $(SRC)
&lt;TAB>$(AR) $(ARFLAGS) libfnv.a $(OBJ) <TAB>$(AR) $(ARFLAGS) libfnv.a $(OBJ)
clean: clean:
&lt;TAB>rm -rf libfnv.a FNVhash *.o <TAB>rm -rf libfnv.a FNVhash *.o
</sourcecode> ]]></sourcecode>
</section> </section>
</section> <!-- 8. --> </section>
<section anchor="iana"> <!-- 9. --> <section anchor="iana">
<name>IANA Considerations</name> <name>IANA Considerations</name>
<t>This document requires no IANA Actions.</t> <t>This document has no IANA actions.</t>
</section> <!-- 9. --> </section>
</middle> </middle>
<!-- ____________________BACK_MATTER____________________ -->
<back> <back>
<references>
<name>References</name>
<references> <references>
<name>Normative References</name> <name>Normative References</name>
<reference anchor="C"> <reference anchor="C">
<front> <front>
<title>The C Programming Language, 2nd Edition</title> <title>The C Programming Language, 2nd Edition</title>
<author fullname="Brian W. Kernighan" initials="B." <author fullname="Brian W. Kernighan" initials="B. W."
surname="Kernighan"> surname="Kernighan">
<organization>AT&amp;T Bell Laboratories</organization> <organization>AT&amp;T Bell Laboratories</organization>
</author> </author>
<author fullname="Denis M. Ritchie" initials="D." <author fullname="Dennis M. Ritchie" initials="D. M."
surname="Ritchie"> surname="Ritchie">
<organization>AT&amp;T Bell Laboratories</organization> <organization>AT&amp;T Bell Laboratories</organization>
</author> </author>
<date year="1978"/> <date year="1988"/>
</front> </front>
<seriesInfo name="ISBN-10" value="0-13-110362-8"/> <seriesInfo name="ISBN-10" value="0-13-110362-8"/>
<seriesInfo name="ISBN-13" value="978-0131103627"/> <seriesInfo name="ISBN-13" value="978-0131103627"/>
</reference> </reference>
<xi:include <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.0020.xml"
href="https://www.rfc-editor.org/refs/bibxml/reference.RFC.0020.xml"/> />
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"
/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"
/>
</references> </references>
<references> <references>
<name>Informative References</name> <name>Informative References</name>
<reference anchor="BASIC" <reference anchor="BASIC" target="http://www.isthe.com/chongo/tech/comp/fnv/inde
target="http://www.isthe.com/chongo/tech/comp/fnv/index.html#PowerBASIC"> x.html#PowerBASIC">
<front> <front>
<title>FNV32 PowerBASIC in line x86 assembler</title> <title>FNV32 PowerBASIC inline x86 assembler</title>
<author fullname="Wayne Diamond" initials="W." <author fullname="Wayne Diamond" initials="W."
surname="Diamond"/> surname="Diamond"/>
</front> </front>
</reference> </reference>
<reference anchor="BFDseq" <!-- draft-ietf-bfd-secure-sequence-numbers
target="draft-ietf-bfd-secure-sequence-numbers-09.txt"> Long way, to reference an old version, per author/AUTH48 -->
<reference anchor="BFDseq">
<front> <front>
<title>Secure BFD Sequence Numbers</title> <title>Secure BFD Sequence Numbers</title>
<author fullname="Mahesh Jethanandani" initials="M." <author fullname="Mahesh Jethanandani" initials="M." surname="Jethanandani">
surname="Jethanandani">
<organization>Kloud Services</organization> <organization>Kloud Services</organization>
<address>
<email>mjethanandani@gmail.com</email>
</address>
</author> </author>
<author fullname="Sonal Agarwal" initials="S." <author fullname="Sonal Agarwal" initials="S." surname="Agarwal">
surname="Agarwal">
<organization>Cisco Systems, Inc</organization> <organization>Cisco Systems, Inc</organization>
<address>
<email>agarwaso@cisco.com</email>
<uri>www.cisco.com</uri>
</address>
</author> </author>
<author fullname="Ashesh Mishra" initials="A." <author fullname="Ashesh Mishra" initials="A." surname="Mishra">
surname="Mishra"> <organization>Aalyria Technologies</organization>
<organization>O3b Networks</organization>
<address>
<email>mishra.ashesh@gmail.com</email>
</address>
</author> </author>
<author fullname="Ankur Saxena" initials="A." <author fullname="Ankur Saxena" initials="A." surname="Saxena">
surname="Saxena"> <organization>HPE</organization>
<organization>Ciena Corporation</organization>
<address>
<email>ankurpsaxena@gmail.com</email>
</address>
</author> </author>
<author fullname="Alan DeKok" initials="A." <author fullname="Alan DeKok" initials="A." surname="DeKok">
surname="DeKok"> <organization>InkBridge Networks</organization>
<organization>Network RADIUS SARL</organization>
<address>
<email>aland@freeradius.org</email>
</address>
</author> </author>
<date year="2022" month="March" day="22"/> <date day="29" month="March" year="2022"/>
</front> </front>
<seriesInfo name="Internet-Draft" value="draft-ietf-bfd-secure-sequence-number s-09"/>
</reference> </reference>
<reference anchor="calc" <reference anchor="calc" target="http://www.isthe.com/chongo/tech/comp/calc/inde
target="http://www.isthe.com/chongo/tech/comp/calc/index.html"> x.html">
<front> <front>
<title>Calc - C-style arbitrary precision calculator</title> <title>Calc - C-style arbitrary precision calculator</title>
<author fullname="David I. Bell" initials="D." <author fullname="David I. Bell" initials="D."
surname="Bell"/> surname="Bell"/>
<author fullname="Landon Curt Noll" initials="L." <author fullname="Landon Curt Noll" initials="L."
surname="Noll"/> surname="Noll"/>
</front> </front>
</reference> </reference>
<reference anchor="Cohesia" <reference anchor="Cohesia" target="http://www.cohesia.com/">
target="http://www.cohesia.com/">
<front> <front>
<title>Cohesia website</title> <title>Cohesia website</title>
<author> <author>
<organization>Cohesia</organization> <organization>Cohesia</organization>
</author> </author>
</front> </front>
</reference> </reference>
<reference anchor="deliantra" <!-- [rfced] References: The provided link for [Cohesia] steers to
target="http://www.deliantra.net/"> <https://cohesia.com/>, which is a business financing site. We could
not find a relationship to the bullet item in Section 1.2. Should a
different website be listed here?
Original:
* [Cohesia] MASS project server collision avoidance,
...
[Cohesia] Cohesia, "Cohesia website", <http://www.cohesia.com/>.
Donald Eastlake: I don't know what this reference is supposed to be. Maybe anot
her author can come up with information as to why we added it. If not, it
should be deleted. -->
<reference anchor="deliantra" target="http://www.deliantra.net/">
<front> <front>
<title>Deliantra MMORPG</title> <title>Deliantra MMORPG</title>
<author> <author>
<organization>The Deliantra Team</organization> <organization>The Deliantra Team</organization>
</author> </author>
<date year="2016"/> <date month="October" day="16" year="2022"/>
</front> </front>
</reference> </reference>
<reference anchor="fasmlab" <reference anchor="fasmlab"
target="https://sourceforge.net/projects/fasmlab/"> target="https://sourceforge.net/projects/fasmlab/">
<front> <front>
<title>Integrated Development Environment</title> <title>Integrated Development Environments</title>
<author> <author>
<organization>Fasmlab</organization> <organization>Fasmlab</organization>
</author> </author>
</front> </front>
</reference> </reference>
<reference anchor="FIPS202" <reference anchor="FIPS202" target="https://nvlpubs.nist.gov/nistpubs/FI
target="https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf"> PS/NIST.FIPS.202.pdf">
<front> <front>
<title>SHA-3 Standard: Permutation-Based Hash and Extendable <title>SHA-3 Standard: Permutation-Based Hash and Extendable-Output
Output Functions</title> Functions</title>
<author> <author>
<organization>National Institute of Standards and <organization abbrev="NIST">National Institute of Standards and Te
Technology</organization> chnology (NIST)
</author> </organization>
<date year="2015" month="8"/> </author>
</front> <date month="August" year="2015"/>
<seriesInfo name="Federal Information Processing Standards </front>
Publicsation" value="FIPS PUB 202"/> <seriesInfo name="FIPS PUB" value="202"/>
<seriesInfo name="DOI" <seriesInfo name="DOI" value="10.6028/NIST.FIPS.202"/>
value="http://dx.doi.org/10.6028/NIST.FIPS.202"/> </reference>
</reference>
<reference anchor="flatassembler" <reference anchor="flatassembler"
target="https://flatassembler.net/"> target="https://flatassembler.net/">
<front> <front>
<title>flat assembler, Assembly language resources</title> <title>flat assembler: Assembly language resources</title>
<author fullname="Tomasz Grysztar" initials="T." <author fullname="Tomasz Grysztar" initials="T."
surname="Grysztar"/> surname="Grysztar"/>
<date year="2025"/> <date year="2025"/>
</front> </front>
</reference> </reference>
<reference anchor="FNV" <reference anchor="FNV"
target="http://www.isthe.com/chongo/tech/comp/fnv/index.html"> target="http://www.isthe.com/chongo/tech/comp/fnv/index.html">
<front> <front>
<title>FNV website</title> <title>FNV (Fowler/Noll/Vo)</title>
<author> <author initials="G." surname="Fowler"/>
<organization>Fowler-Noll-Vo</organization> <author initials="L." surname="Noll"/>
</author> <author initials="K." surname="Vo"/>
</front> </front>
</reference> </reference>
<reference anchor="Fortran" <reference anchor="Fortran"
target="https://stdlib.fortran-lang.org/"> target="https://stdlib.fortran-lang.org/">
<front> <front>
<title>A community driven standard library for (modern) <title>A community driven standard library for (modern)
Fortran</title> Fortran</title>
<author> <author>
<organization>Fortran Standard Library</organization> <organization>Fortran Standard Library</organization>
</author> </author>
</front> </front>
</reference> </reference>
<reference anchor="FragCache" <reference anchor="FragCache"
target="https://www.slideshare.net/slideshow/improving-running-components-at-twi tter/1141786 target="https://www.slideshare.net/slideshow/improving-running-components-at-twi tter/1141786
"> ">
<front> <front>
<title>Improving Running Components at Twitter (see slide 31)</title> <title>Improving Running Components at Twitter</title>
<author fullname="Evan Waever" initials="E." <author fullname="Evan Weaver" initials="E."
surname="Weaver"/> surname="Weaver"/>
<date year="2009"/> <date year="2009"/>
</front> </front>
<refcontent>Slide 31</refcontent>
</reference> </reference>
<reference anchor="FreeBSD" <reference anchor="FreeBSD"
target="http://www.freebsd.org/releases/4.3R/notes.html"> target="https://www.freebsd.org/releases/4.3R/notes.html">
<front> <front>
<title>FreeBSD 4.3 Release Notes</title> <title>FreeBSD 4.3 Release Notes (Last modified on 21 February 2021)</title>
<author> <author fullname="Danilo G. Baio" initials="D. G." surname="Baio"/>
<organization>The Free BSD Project</organization>
</author>
<date year="2025"/> <date year="2025"/>
</front> </front>
<refcontent>The Free BSD Project</refcontent>
</reference> </reference>
<reference anchor="FRET" <reference anchor="FRET"
target="https://fret.sourceforge.net/"> target="https://fret.sourceforge.net/">
<front> <front>
<title>FRET helps understand file formats</title> <title>FRET: helping understand file formats</title>
<author fullname="Michael McCarthy" initials="M." <author fullname="Michael McCarthy" initials="M."
surname="McCarthy"/> surname="McCarthy"/>
<date year="2006" month="1" day="19"/> <date year="2006" month="January" day="19"/>
</front> </front>
</reference> </reference>
<reference anchor="GolfHash" <reference anchor="RimStone"
target="https://golf-lang.com/new-hash.html"> target="https://rimstone-lang.com/">
<front> <front>
<title>Golf Language Hash Tables</title> <title>Golf Language Hash Tables</title>
<author> <author>
<organization>Gliim LLC</organization> <organization>Gliim LLC</organization>
</author> </author>
<date year="2025"/> <date year="2025"/>
</front> </front>
</reference> </reference>
<reference anchor="IEEE" target="http:www.ieee.org"> <reference anchor="IEEE" target="https://www.ieee.org/">
<front> <front>
<title>IEEE website</title> <title>IEEE website</title>
<author> <author>
<organization>Institute for Electrical and Electronics <organization>Institute for Electrical and Electronics
Engineers</organization> Engineers</organization>
</author> </author>
</front> </front>
</reference> </reference>
<reference anchor="IEEE8021Qbp"> <reference anchor="IEEE8021Q-2022" target="https://ieeexplore.ieee.org/doc
<front> ument/10004498">
<title>Media Access Control (MAC) Bridges and Virtual Bridged <front>
Local Area Networks - Equal Cost Multiple Path (ECMP)</title> <title>IEEE Standard for Local and Metropolitan Area Networks--Bridges
<author surname="IEEE 802.1"/> and Bridged Networks</title>
<date year="2014" month="April" day="7"/> <author>
</front> <organization>IEEE</organization>
<seriesInfo name="IEEE Std" value="802.1Qbp-2014"/> </author>
</reference> <date month="December" year="2022"/>
</front>
<seriesInfo name="DOI" value="10.1109/IEEESTD.2022.10004498"/>
<seriesInfo name="IEEE Std" value="802.1Q-2022"/>
</reference>
<reference anchor="IEN137" <reference anchor="IEN137"
target="https://www.rfc-editor.org/ien/ien137.txt"> target="https://www.rfc-editor.org/ien/ien137.txt">
<front> <front>
<title>On Holy Wars and A Plea For Peace</title> <title>On Holy Wars and A Plea For Peace</title>
<author fullname="Danny Cohen" initials="D." <author fullname="Danny Cohen" initials="D."
surname="Cohen"> surname="Cohen">
<organization>USC/ISI</organization> <organization>USC/ISI</organization>
</author> </author>
<date year="1980" month="4" day="1"/> <date year="1980" month="April" day="1"/>
</front> </front>
<seriesInfo name="IEN" value="137"/> <refcontent>IEN 137</refcontent>
</reference> </reference>
<reference anchor="IPv6flow" <reference anchor="IPv6flow"
target="https://researchspace.auckland.ac.nz/bitstream/handle/2292/13240/flowhas hRep.pdf"> target="https://www.cs.auckland.ac.nz/~brian/flowhashRep.pdf">
<front> <front>
<title>Comparing Hash Function Algorithms for the IPv6 Flow <title>Comparing Hash Function Algorithms for the IPv6 Flow
Label</title> Label</title>
<author fullname="Lewis Anderson" initials="L." <author fullname="Lewis Anderson" initials="L."
surname="Anderson"> surname="Anderson">
<organization>The University of Auckland</organization> <organization>The University of Auckland</organization>
<address> <address>
<email>land062@auckland.ac.nz</email> <email>land062@auckland.ac.nz</email>
</address> </address>
</author> </author>
<author fullname="Nevil Brownlee" initials="N." <author fullname="Nevil Brownlee" initials="N."
surname="Brownlee"> surname="Brownlee">
<organization>The University of Auckland</organization> <organization>The University of Auckland</organization>
<address> <address>
<email>n.brownlee@auckland.ac.nz</email> <email>n.brownlee@auckland.ac.nz</email>
</address> </address>
</author> </author>
<author fullname="Brian E. Carpenter" initials="B." <author fullname="Brian E. Carpenter" initials="B. E."
surname="Carpenter"> surname="Carpenter">
<organization>The University of Auckland, Department of Computer <organization>The University of Auckland, Department of Computer
Science</organization> Science</organization>
<address> <address>
<email>brain@cs.auckland.ac.nz</email> <email>brain@cs.auckland.ac.nz</email>
</address> </address>
</author> </author>
<date year="2012" month="March"/> <date year="2012" month="March"/>
</front> </front>
<seriesInfo name="University of Auckland Department of Computer <refcontent>University of Auckland Department of Computer Science Technical Re
Science Technical Report" value="2012-002"/> port 2012-002</refcontent>
<seriesInfo name="ISSN" value="1173-3500"/> <seriesInfo name="ISSN" value="1173-3500"/>
</reference> </reference>
<reference anchor="LCN2" <reference anchor="LCN2"
target="https://github.com/lcn2/fnv"> target="https://github.com/lcn2/fnv">
<front> <front>
<title>lcn2 / fnv</title> <title>lcn2 / fnv</title>
<author fullname="Landon Curt Noll" initials="L." <author fullname="Landon Curt Noll" initials="L."
surname="Noll"> surname="Noll">
<organization>Cisco</organization> <organization>Cisco</organization>
</author> </author>
<author fullname="Cody Boone Ferguson" initials="C." <author fullname="Cody Boone Ferguson" initials="C."
surname="Ferguson"/> surname="Ferguson"/>
<date month="November" day="19" year="2025"/>
</front> </front>
<refcontent>commit 953444c</refcontent>
</reference> </reference>
<reference anchor="Leprechaun" <reference anchor="Leprechaun"
target="http://www.sanmayce.com/Downloads/"> target="http://www.sanmayce.com/Downloads/">
<front> <front>
<title>Sanmayce project 'Underdog Way'</title> <title>Sanmayce project 'Underdog Way'</title>
<author> <author>
<organization>Sanmayce project</organization> <organization>Sanmayce project</organization>
</author> </author>
</front> </front>
</reference> </reference>
<reference anchor="libstr" <reference anchor="libketama"
target="https://www.metabrew.com/article/libketama-consistent-hashing-algo-memca
ched-clients">
<front>
<title>libketama: Consistent Hashing library for memcached clients</title>
<author initials="R." surname="Jones"/>
<date month="April" day="10" year="2007"/>
</front>
</reference>
<reference anchor="libsir"
target="https://github.com/aremmell/libsir"> target="https://github.com/aremmell/libsir">
<front> <front>
<title>libstr logging library</title> <title>libsir logging library</title>
<author initials="R." surname="Lederman"/> <author initials="R." surname="Lederman"/>
<author initials="J." surname="Johnson"/> <author initials="J." surname="Johnson"/>
<date month="December" day="03" year="2025"/>
</front> </front>
<refcontent>commit 0ae0173</refcontent>
</reference> </reference>
<reference anchor="memcache" <reference anchor="memcache"
target="http://pecl.php.net/package/memcache"> target="https://pecl.php.net/package/memcache">
<front> <front>
<title>PHP memcached extension</title> <title>PHP memcached extension</title>
<author initials="A." surname="Dovgal"> <author initials="A." surname="Dovgal">
<organization>The PHP Group</organization> <organization>The PHP Group</organization>
</author> </author>
<author initials="P." surname="Joye"> <author initials="P." surname="Joye">
<organization>The PHP Group</organization> <organization>The PHP Group</organization>
</author> </author>
<author initials="H." surname="Radtke"> <author initials="H." surname="Radtke">
<organization>The PHP Group</organization> <organization>The PHP Group</organization>
</author> </author>
<author initials="M." surname="Johansson"> <author initials="M." surname="Johansson">
<organization>The PHP Group</organization> <organization>The PHP Group</organization>
</author> </author>
<author initials="T." surname="Srnka"> <author initials="T." surname="Srnka">
<organization>The PHP Group</organization> <organization>The PHP Group</organization>
</author> </author>
<date year="2023" month="4" day="30"/> <date year="2023" month="April" day="30"/>
</front> </front>
</reference> </reference>
<referencegroup anchor="NCHF"> <referencegroup anchor="NCHF">
<reference anchor="NCHF1" <reference anchor="NCHF1" target="https://cacm.acm.org/practice/questioning-th
target="https://cacm.acm.org/practice/questioning-the-criteria-for-evaluat e-criteria-for-evaluating-non-cryptographic-hash-functions/">
ing-non-cryptographic-hash-functions/">
<front> <front>
<title>Questioning the Criteria for Evaluating Non-Cryptographic <title>Questioning the Criteria for Evaluating Non-Cryptographic
Hash Functions</title> Hash Functions</title>
<author fullname="Catherine Hayes" initials="C." surname="Hayes"> <author fullname="Catherine Hayes" initials="C." surname="Hayes">
<organization>Maynooth University</organization> <organization>Maynooth University</organization>
</author> </author>
<author fullname="David Malone" initials="D." surname="Malone"> <author fullname="David Malone" initials="D." surname="Malone">
<organization>Maynooth University</organization> <organization>Maynooth University</organization>
</author> </author>
<date year="2025" month="1" day="15"/> <date year="2025" month="February"/>
</front> </front>
<refcontent>Communications of the ACM, Vol. 68 No. 2, pp. 46-51</refcontent>
<seriesInfo name="DOI" value="10.1145/3704255"/> <seriesInfo name="DOI" value="10.1145/3704255"/>
</reference> </reference>
<reference anchor="NCHF2" <reference anchor="NCHF2"
target="https://ieeexplore.ieee.org/abstract/document/10603139"> target="https://ieeexplore.ieee.org/abstract/document/10603139">
<front> <front>
<title>An Evaluation of FNV Non-Cryptographic Hash <title>An Evaluation of FNV Non-Cryptographic Hash
Functions</title> Functions</title>
<author fullname="Catherine Hayes" initials="C." surname="Hayes"> <author fullname="Catherine Hayes" initials="C." surname="Hayes">
<organization>Maynooth University</organization> <organization>Maynooth University</organization>
</author> </author>
<author fullname="David Malone" initials="D." surname="Malone"> <author fullname="David Malone" initials="D." surname="Malone">
<organization>Maynooth University</organization> <organization>Maynooth University</organization>
</author> </author>
<date year="2024" month="June"/> <date year="2024" month="June"/>
</front> </front>
<refcontent>Proceedings of the 35th Irish Signals and Systems Conference (ISSC )</refcontent>
<seriesInfo name="DOI" <seriesInfo name="DOI"
value="10.1109/ISSC61953.2024.10603139"/> value="10.1109/ISSC61953.2024.10603139"/>
</reference> </reference>
</referencegroup> </referencegroup>
<xi:include <xi:include
href="https://www.rfc-editor.org/refs/bibxml/reference.RFC.3174.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3174.xml"/>
<xi:include <xi:include
href="https://www.rfc-editor.org/refs/bibxml/reference.RFC.6194.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6194.xml"/>
<xi:include <xi:include
href="https://www.rfc-editor.org/refs/bibxml/reference.RFC.6234.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6234.xml"/>
<xi:include <xi:include
href="https://www.rfc-editor.org/refs/bibxml/reference.RFC.6437.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6437.xml"/>
<xi:include <xi:include
href="https://www.rfc-editor.org/refs/bibxml/reference.RFC.7357.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7357.xml"/>
<xi:include <xi:include
href="https://www.rfc-editor.org/refs/bibxml/reference.RFC.7873.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7873.xml"/>
<xi:include <xi:include
href="https://www.rfc-editor.org/refs/bibxml/reference.RFC.8200.xml"/> href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8200.xml"/>
<reference anchor="twistylists" <reference anchor="twistylists"
target="https://twistylists.blogspot.com/"> target="https://twistylists.blogspot.com/">
<front> <front>
<title>A no-sort namespace engine</title> <title>twistylists: A no-sort namespace engine; developers invited</title>
<author> <author fullname="Dave Zethmayr" initials="D." surname="Zethmayr">
<organization>twistylists</organization> <organization/>
</author> </author>
<date year="2012"/> <date month="November" day="6" year="2012"/>
</front>
</reference>
<reference anchor="Vely"
target="https://www.linuxlinks.com/vely-general-purpose-framework/">
<front>
<title>Vely - general purpose framework</title>
<author fullname="Sergio Mijatovic" initials="S."
surname="Mijatovic"/>
</front> </front>
</reference> </reference>
<reference anchor="Vortetty" <reference anchor="Smash"
target="https://github.com/Vortetty/gba-rtx"> target="https://www.linuxlinks.com/smash-find-duplicate-files-super-fast/">
<front> <front>
<title>Raytracing for the gba</title> <title>Smash - find duplicate files super fast</title>
<author surname="Vortetty"/> <author fullname="Steven Emms" initials="S." surname="Emms"/>
<date month="December" day="8" year="2024"/>
</front> </front>
</reference> </reference>
</references>
</references> </references>
<section anchor="Effort"> <!-- Appendix A --> <section anchor="Effort">
<name>Work Comparison with SHA-1 and SHA-256</name> <name>Work Comparison with SHA-1 and SHA-256</name>
<t>This appendix provides a simplistic rough comparison of the level <t>This appendix provides a simplistic rough comparison of the level
of effort required to compute FNV-1a, SHA-1 <xref of effort required to compute FNV-1a, SHA-1 <xref
target="RFC3174"/>, and SHA-256 <xref target="RFC6234"/> for short target="RFC3174"/>, and SHA-256 <xref target="RFC6234"/> for short
messages, that is, those less than around 50 bytes. Some CPUs may have messages -- that is, those less than around 50 bytes. Some CPUs may have
special instructions or other hardware to accelerate certain special instructions or other hardware to accelerate certain
cryptographic operations so, if performance is particularly important cryptographic operations, so if performance is particularly important
for an application, benchmarking on the target platform would be for an application, benchmarking on the target platform would be
appropriate.</t> appropriate.</t>
<t>Ignoring transfer of control and conditional tests and equating all <t>Ignoring transfer of control and conditional tests, and equating all
logical and arithmetic operations, FNV requires 2 operations per byte, logical and arithmetic operations, FNV requires two operations per byte:
an XOR and a multiply.</t> an XOR operation and a multiply operation.</t>
<t>SHA-1 and SHA-256 are actually designed to accept a bit vector <t>SHA-1 and SHA-256 are actually designed to accept a bit vector
input although almost all computer uses apply them to an integer input, although almost all computer uses apply them to an integer
number of bytes. They both process blocks of 512 bits (64 bytes) and number of bytes. They both process blocks of 512 bits (64 bytes), and
we estimate the effort involved in processing a full block. There is we estimate the effort involved in processing a full block. There is
some overhead per message to indicate message termination and some overhead per message to indicate message termination and
size. Assuming the message is an even number of bytes, this overhead size. Assuming that the message is an even number of bytes, this overhead
would be 9 bytes for SHA-1 and 17 bytes for SHA-256. So, assuming the would be 9 bytes for SHA-1 and 17 bytes for SHA-256. So, assuming that the
message with that overhead fits into one block, the message would be message with that overhead fits into one block, the message would be
up to 55 bytes for SHA-1 or up to 47 bytes for SHA-256.</t> up to 55 bytes for SHA-1 or up to 47 bytes for SHA-256.</t>
<t>SHA-1 is a relatively weak cryptographic hash function producing a <t>SHA-1 is a relatively weak cryptographic hash function producing a
160-bit hash. It has been partially broken <xref 160-bit hash. It has been substantially broken <xref
target="RFC6194"/>. Ignoring SHA-1's initial set up, transfer of target="RFC6194"/>. Ignoring SHA-1's initial setup, transfer of
control, and conditional tests, but counting all logical and control, and conditional tests, but counting all logical and
arithmetic operations, including counting indexing as an addition, arithmetic operations, including counting indexing as an addition,
SHA-1 requires 1,744 operations per 64 bytes block or 31.07 operations SHA-1 requires 1,744 operations per 64-byte block or 31.07 operations
per byte for a message of 55 bytes. By this rough measure, it is a per byte for a message of 55 bytes. By this rough measure, it is a
little over 15.5 times the effort of FNV.</t> little over 15.5 times the effort of FNV.</t>
<t>SHA-256 is, at the time of publication, considered to be a stronger <t>SHA-256 is, at the time of publication, considered to be a stronger
cryptographic hash function than SHA-1. Ignoring SHA-256's initial set cryptographic hash function than SHA-1. Ignoring SHA-256's initial setup, transf
up, transfer of control, and conditional tests, but counting all er of control, and conditional tests, but counting all
logical and arithmetic operations, SHA-1 requires 2,058 operations per logical and arithmetic operations, SHA-1 requires 2,058 operations per
64 bytes block or 48.79 operations per byte for a message of 47 64-byte block or 48.79 operations per byte for a message of 47
byte. By this rough measure, it is over 24 times the effort of bytes. By this rough measure, it is over 24 times the effort of
FNV.</t> FNV.</t>
<t>However, FNV is commonly used for short inputs so a comparison for <t>However, FNV is commonly used for short inputs, so doing a comparison of
such inputs is relevant. Using the above comparison method, for inputs such inputs is relevant. Using the above comparison method, for inputs
of N bytes, where N is &lt;= 55 so SHA-1 will take one block, the of N bytes, where N is &lt;= 55 so SHA-1 will take one block, the
ratio of the effort for SHA-1 to the effort for FNV will be 872/N. ratio of the effort for SHA-1 to the effort for FNV will be 872/N.
For inputs of N bytes, where N is &lt;= 47 so SHA-256 will take one For inputs of N bytes, where N is &lt;= 47 so SHA-256 will take one
block, the ratio of the effort for SHA-256 to the effort for FNV will block, the ratio of the effort for SHA-256 to the effort for FNV will
be 1029/N. Some examples are given below.</t> be 1029/N. Some examples are given below.</t>
<table> <table>
<thead> <thead>
<tr><td>Example</td><td align="right">Length in Bytes</td><td <tr><th>Example</th><th align="right">Length in Bytes</th>
align="right">SHA-1 Effort Relative to FNV Effort</td><td <th align="right">SHA-1 Effort Relative to FNV Effort</th>
align="right">SHA-256 Effort Relative to FNV Effort</td></tr> <th align="right">SHA-256 Effort Relative to FNV Effort</th></tr>
</thead> </thead>
<tbody> <tbody>
<tr><td>IPv4 address</td><td align="right">4</td><td <tr><td>IPv4 address</td><td align="right">4</td><td
align="right">218</td><td align="right">514</td></tr> align="right">218</td><td align="right">514</td></tr>
<tr><td>MAC address</td><td align="right">6</td><td <tr><td>MAC address</td><td align="right">6</td><td
align="right">145</td><td align="right">171</td></tr> align="right">145</td><td align="right">171</td></tr>
<tr><td>IPv6 address</td><td align="right">16</td><td <tr><td>IPv6 address</td><td align="right">16</td><td
align="right">54</td><td align="right">64</td></tr> align="right">54</td><td align="right">64</td></tr>
</tbody> </tbody>
</table> </table>
</section> <!-- Appendix A --> </section>
<section> <!-- Appendix B --> <section>
<name>Previous IETF FNV Code</name> <name>Previous IETF FNV Code</name>
<t>FNV-1a was referenced in draft-ietf-tls-cached-info-08.txt that has <t>FNV-1a was referenced in draft-ietf-tls-cached-info-08
since expired. Below is the Java code for FNV64 from that TLS draft (which was ultimately published as RFC 7924, but RFC 7924 no longer contains the
included with the kind permission of the author:</t> code below). Herein, we provide the Java code for FNV64 from that earlier draft
, included with the kind permission of the author:</t>
<sourcecode type="java" markers="true"> <!-- [LB] Marking sourcecode, including the "Java code sample ..."
header, as DNE; pulled from draft-ietf-tls-cached-info-08
(2010 precursor to RFC 7924 (published in 2016)). The code here
doesn't match the code in draft-ietf-tls-cached-info-08, though,
so AQed to see if the differences should be mentioned in some way. -->
<!-- Begin DNE code -->
<sourcecode type="java" markers="true"><![CDATA[
/* /*
* Java code sample, implementing 64 bit FNV-1a * Java code sample, implementing 64 bit FNV-1a
* By Stefan Santesson * By Stefan Santesson
*/ */
import java.math.BigInteger; import java.math.BigInteger;
public class FNV { public class FNV {
static public BigInteger getFNV1aToByte(byte[] inp) { static public BigInteger getFNV1aToByte(byte[] inp) {
BigInteger m = new BigInteger("2").pow(64); BigInteger m = new BigInteger("2").pow(64);
BigInteger fnvPrime = new BigInteger("1099511628211"); BigInteger fnvPrime = new BigInteger("1099511628211");
BigInteger fnvOffsetBasis = BigInteger fnvOffsetBasis =
new BigInteger("14695981039346656037"); new BigInteger("14695981039346656037");
BigInteger digest = fnvOffsetBasis; BigInteger digest = fnvOffsetBasis;
for (byte b : inp) { for (byte b : inp) {
digest = digest.xor(BigInteger.valueOf((int) b &amp; 255)); digest = digest.xor(BigInteger.valueOf((int) b & 255));
digest = digest.multiply(fnvPrime).mod(m); digest = digest.multiply(fnvPrime).mod(m);
} }
return digest; return digest;
} }
} }
</sourcecode> ]]></sourcecode>
<!-- End DNE code -->
</section>
<section>
<name>Change History</name>
<t>RFC Editor Note: Please delete this appendix on publication.</t>
<section>
<name>From -00 to -01</name>
<ol>
<li>Add Security Considerations section on why FNV is
non-cryptographic.</li>
<li>Add Appendix A on a work factor comparison with SHA-1.</li>
<li>Add Appendix B concerning previous IETF draft referenced to
FNV.</li>
<li>Minor editorial changes.</li>
</ol>
</section>
<section>
<name>From -01 to -02</name>
<ol>
<li>Correct FNV_Prime determination criteria and add note as to why
s &lt; 5 and s > 10 are not considered.</li>
<li>Add acknowledgements list.</li>
<li>Add a couple of references.</li>
<li>Minor editorial changes.</li>
</ol>
</section>
<section>
<name>From -02 to -05</name>
<ol>
<li>Minor addition to Section 6, point 3.</li>
<li>Add Twitter as a use example and IPv6 flow hash study
reference.</li>
<li>Minor editorial changes.</li>
</ol>
</section>
<section>
<name>From -05 to -08</name>
<ol>
<li>Add code subsections.</li>
<li>Update Author info.</li>
<li>Minor edits.</li>
</ol>
</section>
<section>
<name>From -08 to -09</name>
<ol>
<li>Change reference for ASCII to <xref target="RFC0020"/>.</li>
<li>Add more details on history of the string used to compute
offset_basis.</li>
<li>Re-write "Work Factor" part of Section 6 to be more
precise.</li>
<li>Minor editorial changes.</li>
</ol>
</section>
<section>
<name>From -09 to -10</name>
<ol>
<li>Inclusion of initial partial version of code and some
documentation about the code, Section 9.</li>
<li>Insertion of new Section 4 on hashing values.</li>
</ol>
</section>
<section>
<name>From -10 to -12</name>
<t>Changes based on code improvements primarily from Tony Hansen who
has been added as an author. Changes based on comments from Mukund
Sivaraman and Roman Donchenko.</t>
</section>
<section>
<name>From -12 to -13</name>
<t>Fixed bug in pseudocode in Section 2.3.</t>
<t>Change code to eliminate the BigEndian flag and so there are
separate byte vector output routines for FNV32 and FNV64, equivalent
to the other routines, and integer output routines for cases where
Endian-ness consistency is not required.</t>
</section>
<section>
<name>From -13 to -17</name>
<ol>
<li>Update an author address</li>
<li>Update an author affiliation.</li>
</ol>
</section>
<section>
<name>From -17 to -19</name>
<ol>
<li>Add reference to draft-ietf-bfd-secure-sequence-numbers.</li>
<li>Add references to the following, each of which uses FNV: RFC
7357, RFC 7873, and IEEE Std. 802.1Qbp-2014</li>
<li>Update author information</li>
<li>Minor editorial changes.</li>
</ol>
</section>
<section>
<name>From -19 to -20</name>
<t>Convert to XML v3. Fix code for longer FNV hashes.</t>
</section>
<section>
<name>From -20 to -21</name>
<t>Update Twitter to X. Minor Editorial changes.</t>
</section>
<section>
<name>From -21 to -22</name>
<t>Update Landon's email. Minor Editorial changes. Update to
substantially improved code.</t>
</section>
<section>
<name>From -22 to -23</name>
<ol>
<li>Author info update.</li>
<li>Make byte vector returning versions of
functions available for all sizes.</li>
<li>Remove BigEndian code due to difficulty in finding someone to
test it. This only affects multi-byte integer returns and correct
results can always be obtained by using the byte vector return
versions of functions.</li>
</ol>
</section>
<section>
<name>From -23 to -25</name>
<ol>
<li>Correct some errors in comments in the code, fix some
omissions and add testing for the file hashing code, and other
code polishing</li>
<li>Minor editorial changes.</li>
</ol>
</section>
<section>
<name>From -25 to -28</name>
<ol>
<li>Add autodetect in FNVconfig.h of target support for 64-bit
integers.</li>
<li>Add discussion of what source files are needed for particular
uses.</li>
<li>Fix code so it compiles properly if all .c files are
concatenated as well as when they are compiled separately.</li>
<li>Add makefile section.</li>
<li>Fix some problems with &amp;gt; and >.</li>
<li>Minor editorial improvements.</li>
</ol>
</section>
<section>
<name>From -28 to -29</name>
<t>Responding to some IETF Last Call Comments: minor re-organization
of Introduction and addition to the Introduction of a some
non-applicability considerations. Minor editorial improvements.</t>
</section>
<section>
<name>From -29 to -30</name>
<ol>
<li>Reorganize Section 1 and add to it a subsection on the
applicability of non-cryptographic hash functions.</li>
<li>Rewrite and expand <xref target="bang"/> on inducing
collisions.</li>
<li>Add material on parallelization to the section on hashing
multiple values.</li>
<li>Add a reference to IEN 137 on Endian-ness.</li>
<li>Minor editorial improvements.</li>
<li>Minor coding changes including adding function calls
supporting variant offset_basis values and reducing the size of
main.c through the use of C pre-processor macros.</li>
</ol>
</section>
<section>
<name>From -30 to -31</name>
<ol>
<li>Add more uses of FNV to <xref target="Uses"/>.</li>
<li>Fix instructions for reporting uses of FNV.</li>
<li>Minor editing changes.</li>
</ol>
</section>
<section>
<name>From -31 to -32</name>
<ol>
<li>Move purpose sentence for this draft from the beginning of
Section 6 to the Introduction.</li>
<li>Minor editing changes.</li>
</ol>
</section>
<section>
<name>From -32 to -33</name>
<ol>
<li>Edit based on Independent Submissions Editor review. Includes
moving around some material, creation of the Historical Notes
Appendix, add additional uses including references for some uses,
etc.</li>
<li>Add <xref target="C"/>, <xref target="LCN2"/>, and <xref
target="Vely"/> to References.</li>
<li>Minor editing changes.</li>
</ol>
</section>
<section>
<name>From -33 to -34</name>
<t>Add "This work is not an Internet standard and is not the result
of consensus of the IETF community." to the Introduction.</t>
</section>
<section>
<name>From -34 to -35</name>
<t>Update based on reviews as follows:</t>
<ol>
<li>Add references to SHA3 <xref target="FIPS202"/>.</li>
<li>Slightly simplify the wording of <xref
target="applicability"/>.</li>
<li>Add <xref target="NCHF"/> reference group.</li>
<li>Make it clear that the Section 2 pseudocode uses modulus
arithmetic mod 2**HashSize.</li>
<li>Mention in Section 8 that some other source code might be
more optimized.</li>
<li>Mention in Appendix A that some CPUs may have hardware that
accelerates some cryptographic operations and, if performance is
important for a particular application, benchmarking on the target
platform would be appropriate.</li>
<li>Augment Appendix A with rough computational effort estimates
for SHA-256 as well as SHA-1 and reformat examples as a table.</li>
<li>Minor editing changes.</li>
</ol>
</section>
</section> </section>
<section anchor="Acknowledgements" numbered="false"> <section anchor="Acknowledgements" numbered="false">
<name>Acknowledgements</name> <name>Acknowledgements</name>
<t>The contributions of the following, listed in alphabetical order,
<t>The contributions of the following, listed is alphabetic order,
are gratefully acknowledged:</t> are gratefully acknowledged:</t>
<t>Roman Donchenko, Frank Ellermann, Stephen Farrell, Tony Finch, <t><contact fullname="Roman Donchenko"/>, <contact fullname="Frank
Charlie Kaufman, Eliot Lear, Bob Moskowitz, Gayle Noble, Stefan Ellermann"/>, <contact fullname="Stephen Farrell"/>, <contact fullname="Tony
Santesson, Mukund Sivaraman, Paul Hoffman, and Paul Wouters.</t> Finch"/>, <contact fullname="Paul Hoffman"/>, <contact fullname="Charlie Kaufm
an"/>, <contact fullname="Eliot
Lear"/>, <contact fullname="Bob Moskowitz"/>, <contact fullname="Gayle
Noble"/>, <contact fullname="Stefan Santesson"/>, <contact fullname="Mukund
Sivaraman"/>,
and <contact fullname="Paul Wouters"/>.</t>
</section> </section>
</back> </back>
</rfc> </rfc>
 End of changes. 467 change blocks. 
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