Network Working Group Glenn Fowler
INTERNET-DRAFT Google
Intended Status: Informational Landon Curt Noll
Cisco Systems
Kiem-Phong Vo
Google
Donald Eastlake
Huawei Technologies
Tony Hansen
AT&T Laboratories
Expires: November 28, 2019 May 29, 2019
The FNV Non-Cryptographic Hash Algorithm
<draft-eastlake-fnv-17.txt>
Abstract
FNV (Fowler/Noll/Vo) is a fast, non-cryptographic hash algorithm with
good dispersion. The purpose of this document is to make information
on FNV and open source code performing FNV conveniently available to
the Internet community.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Distribution of this document is unlimited. Comments should be sent
to the authors.
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The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft
Shadow Directories can be accessed at
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G. Fowler, L. Noll, K. Vo, et. al [Page 1]
INTERNET-DRAFT FNV
Table of Contents
1. Introduction............................................3
2. FNV Basics..............................................4
2.1 FNV Primes.............................................4
2.2 FNV offset_basis.......................................5
2.3 FNV Endianism..........................................6
3. Other Hash Sizes and XOR Folding........................7
4. Hashing Multiple Values Together........................8
5. FNV Constants...........................................9
6. The Source Code........................................11
6.1 FNV-1a C Code.........................................11
6.1.1 FNV32 Code..........................................15
6.1.2 FNV64 C Code........................................26
6.1.3 FNV128 C Code.......................................48
6.1.4 FNV256 C Code.......................................59
6.1.5 FNV512 C Code.......................................71
6.1.6 FNV1024 C Code......................................82
6.2 FNV Test Code.........................................95
7. Security Considerations...............................108
7.1 Why is FNV Non-Cryptographic?........................108
7.2 Inducing Collisions..................................109
8. IANA Considerations...................................110
Normative References.....................................110
Informative References...................................110
Acknowledgements.........................................111
Appendix A: Work Comparison with SHA-1...................112
Appendix B: Previous IETF Reference to FNV...............113
Appendix C: A Few Test Vectors...........................114
Appendix Z: Change Summary...............................115
From -00 to -01..........................................115
From -01 to -02..........................................115
From -02 to -03..........................................115
From -03 to -04..........................................115
From -04 to -05..........................................116
From -05 to -06..........................................116
From -06 to -07 to -08...................................116
From -08 to -09..........................................116
From -09 to -10..........................................116
From -10 to -11..........................................117
From -11 to -12..........................................117
From -12 to -13..........................................117
From -13 to -14 to -15 to -16 to -17.....................117
G. Fowler, L. Noll, K. Vo, et. al [Page 2]
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1. Introduction
The FNV hash algorithm is based on an idea sent as reviewer comments
to the [IEEE] POSIX P1003.2 committee by Glenn Fowler and Phong Vo in
1991. In a subsequent ballot round Landon Curt Noll suggested an
improvement on their algorithm. Some people tried this hash and found
that it worked rather well. In an EMail message to Landon, they named
it the "Fowler/Noll/Vo" or FNV hash. [FNV]
FNV hashes are designed to be fast while maintaining a low collision
rate. The high dispersion of the FNV hashes makes them well suited
for hashing nearly identical strings such as URLs, hostnames,
filenames, text, IP addresses, etc. Their speed allows one to quickly
hash lots of data while maintaining a reasonably low collision rate.
However, they are generally not suitable for cryptographic use. (See
Section 7.1.)
The FNV hash is widely used, for example in DNS servers, the Twitter
service, database indexing hashes, major web search / indexing
engines, netnews history file Message-ID lookup functions, anti-spam
filters, a spellchecker programmed in Ada 95, flatassembler's open
source x86 assembler - user-defined symbol hashtree, non-
cryptographic file fingerprints, computing Unique IDs in DASM (DTN
(Delay Tolerant Networking) Applications for Symbian Mobile-phones),
Microsoft's hash_map implementation for VC++ 2005, the realpath cache
in PHP 5.x (php-5.2.3/TSRM/tsrm_virtual_cwd.c), and many other uses.
A study has recommended FNV in connection with the IPv6 Flow Label
field [IPv6flow].
FNV hash algorithms and source code have been released into the
public domain. The authors of the FNV algorithm took deliberate steps
to disclose the algorithm in a public forum soon after it was
invented. More than a year passed after this public disclosure and
the authors deliberately took no steps to patent the FNV algorithm.
Therefore, it is safe to say that the FNV authors have no patent
claims on the FNV algorithm as published.
If you use an FNV function in an application, you are kindly
requested to send an EMail about it to: fnv-mail@asthe.com
G. Fowler, L. Noll, K. Vo, et. al [Page 3]
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2. FNV Basics
This document focuses on the FNV-1a function whose pseudo-code is as
follows:
hash = offset_basis
for each octet_of_data to be hashed
hash = hash xor octet_of_data
hash = hash * FNV_Prime
return hash
In the pseudo-code above, hash is a power-of-two number of bits (32,
64, ... 1024) and offset_basis and FNV_Prime depend on the size of
hash.
The FNV-1 algorithm is the same, including the values of offset_basis
and FNV_Prime, except that the order of the two lines with the "xor"
and multiply operations are reversed. Operational 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 zero.
FNV-1a is suggested for general use.
2.1 FNV Primes
The theory behind FNV_Prime's is beyond the scope of this document
but the basic property to look for is how an FNV_Prime would impact
dispersion. Now, consider any n-bit FNV hash where n is >= 32 and
also a power of 2, in particular n = 2**s. For each such n-bit FNV
hash, an FNV_Prime p is defined as:
When s is an integer and 4 < s < 11, then FNV_Prime is the
smallest prime p of the form:
256**int((5 + 2**s)/12) + 2**8 + b
where b is an integer such that:
0 < b < 2**8
The number of one-bits in b is 4 or 5
and where ( p mod (2**40 - 2**24 - 1) ) > (2**24 + 2**8 + 2**7).
Experimentally, FNV_Primes matching the above constraints tend to
have better dispersion properties. They improve the polynomial
feedback characteristic when an FNV_Prime multiplies an intermediate
hash value. As such, the hash values produced are more scattered
throughout the n-bit hash space.
G. Fowler, L. Noll, K. Vo, et. al [Page 4]
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The case where s < 5 is not considered because the resulting hash
quality is too low. Such small hashes can, if desired, be derived
from a 32 bit FNV hash by XOR folding (see Section 3). The case 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 more complex, due to the sparsity of such large primes, and would
needlessly clutter the criteria given above.
Per the above constraints, an FNV_Prime should have only 6 or 7 one-
bits in it. Therefore, some compilers may seek to improve the
performance of a multiplication with an FNV_Prime by replacing the
multiplication with shifts and adds. However, note that the
performance of this substitution is highly hardware-dependent and
should be done with care. FNV_Primes were selected primarily for the
quality of resulting hash function, not for compiler optimization.
2.2 FNV offset_basis
The offset_basis values for the n-bit FNV-1a algorithms are computed
by applying the n-bit FNV-0 algorithm to the 32 octets representing
the following character string in [RFC20]:
chongo <Landon Curt Noll> /\../\
The \'s in the above string are not C-style escape characters. In C-
string notation, these 32 octets are:
"chongo <Landon Curt Noll> /\\../\\"
That string was used because the person testing FNV with non-zero
offset_basis values was looking at an email message from Landon and
was copying his standard email signature line; however, they couldn't
see very well and copied it incorrectly. In fact, he uses
chongo (Landon Curt Noll) /\oo/\
but, since it doesn't matter, no effort has been made to correct
this.
In the general case, almost any offset_basis will serve so long as it
is non-zero. The choice of a non-standard offset_basis may be
beneficial in defending against some attacks that try to induce hash
collisions.
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2.3 FNV Endianism
For persistent storage or interoperability between different hardware
platforms, an FNV hash shall be represented in the little endian
format. That is, the FNV hash will be stored in an array hash[N] with
N bytes such that its integer value can be retrieved as follows:
unsigned char hash[N];
for ( i = N-1, value = 0; i >= 0; --i )
value = ( value << 8 ) + hash[i];
Of course, when FNV hashes are used in a single process or a group of
processes sharing memory on processors with compatible endian-ness,
the natural endian-ness of those processors can be used regardless of
its type, little, big, or some other exotic form.
The code provided in Section 6 has FNV hash functions that return a
little endian byte vector. Because they are slightly more efficient,
code returning FNV hashes of 32-bit or 64-bit size as integers, on
computers supporting integers of those sides, are also provided. Such
integers are compatible with the same size byte vectors on little
endian computers but use of the functions returning integers on big
endian or other non-little-endian machines will be byte-reversed or
otherwise incompatible with the byte vectors.
G. Fowler, L. Noll, K. Vo, et. al [Page 6]
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3. Other Hash Sizes and XOR Folding
Many hash uses require a hash that is not one of the FNV sizes for
which constants are provided in Section 5. If a larger hash size is
needed, please contact the authors of this document.
Most hash applications make use of a hash that is a fixed size binary
field. Assume that k bits of hash are desired and k is less than 1024
but not one of the sizes for which constants are provided in Section
5. The recommended technique is to take the smallest FNV hash of size
S, where S is larger than k, and calculate the desired k-bit-hash
using xor folding as shown below. The final bit masking operation is
logically unnecessary if the size of the variable k-bit-hash is
exactly k bits.
temp = FNV_S ( data-to-be-hashed )
k-bit-hash = ( temp xor temp>>k ) bitwise-and ( 2**k - 1 )
Hash functions are a trade-off between speed and strength. For
example, 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 performing such data folding using a k equal to the size of the
desired output. However, if a much stronger hash, for example one
suitable for cryptographic applications, is wanted, algorithms
designed for that purpose, such as those in [RFC6234], should be
used.
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
hash size S such that 2**S > max. Then calculate the following:
FNV_S mod ( max+1 )
The resulting remainder will be in the range desired but will 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
further processing is needed. If this bias is unacceptable, it can be
avoided by retrying for certain high values of hash, as follows,
before applying the mod operation above:
X = ( int( ( 2**S - 1 ) / ( max+1 ) ) ) * ( max+1 )
while ( hash >= X )
hash = ( hash * FNV_Prime ) + offset_basis
G. Fowler, L. Noll, K. Vo, et. al [Page 7]
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4. Hashing Multiple Values Together
It is common for there to be a few different component values, say
three strings X, Y, and Z, where a hash over all of them is desired.
The simplest thing to do is to concatenate them and compute the hash
of that concatenation, as in
hash ( X | Y | Z )
where the vertical bar character ("|") represents string
concatenation. Note that, for FNV, the same hash results if X, Y,
and Z are actually concatenated and the FNV hash applied to the
resulting string or if FNV is calculated on an initial substring and
the result used as the offset_basis when calculating the FNV hash of
the remainder of the string. This can be done several times.
Assuming FNVoffset_basis ( v, w ) is FNV of w using v as the
offset_basis, then in the example above, fnvx = FNV ( X ) could be
calculated and then fnvxy = FNVoffset_basis ( fnvx, Y ), and finally
fnvxyz = FNVoffset_basis ( fnvxy, Z). The resulting fnvxyz would be
the same as FNV ( X | Y | Z );
Cases are also common where such a hash needs to be repeatedly
calculated where the component values vary but some vary more
frequently than others. For example, assume some sort of computer
network traffic flow ID, such as the IPv6 flow ID [RFC6437], is to be
calculated for network packets based on the source and destination
IPv6 address and the Traffic Class [RFC2460]. If the Flow ID is
calculated in the originating host, the source IPv6 address would
likely always be the same or perhaps assume one of a very small
number of values. By placing this quasi-constant IPv6 source address
first in the string being FNV hashed, FNV ( IPv6source ) could be
calculated and used as the offset_basis for calculating FNV of the
IPv6 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 saving computational resources. The code in this document
includes functions facilitating the use of a non-standard
offset_basis.
G. Fowler, L. Noll, K. Vo, et. al [Page 8]
INTERNET-DRAFT FNV
5. FNV Constants
The FNV Primes are as follows:
32 bit FNV_Prime = 2**24 + 2**8 + 0x93 = 16,777,619
= 0x01000193
64 bit FNV_Prime = 2**40 + 2**8 + 0xB3 = 1,099,511,628,211
= 0x00000100 000001B3
128 bit FNV_Prime = 2**88 + 2**8 + 0x3B =
309,485,009,821,345,068,724,781,371
= 0x00000000 01000000 00000000 0000013B
256 bit FNV_Prime = 2**168 + 2**8 + 0x63 =
374,144,419,156,711,147,060,143,317,175,368,453,031,918,731,002,211 =
0x0000000000000000 0000010000000000 0000000000000000 0000000000000163
512 bit FNV_Prime = 2**344 + 2**8 + 0x57 = 35,
835,915,874,844,867,368,919,076,489,095,108,449,946,327,955,754,392,
558,399,825,615,420,669,938,882,575,126,094,039,892,345,713,852,759 =
0x0000000000000000 0000000000000000 0000000001000000 0000000000000000
0000000000000000 0000000000000000 0000000000000000 0000000000000157
1024 bit FNV_Prime = 2**680 + 2**8 + 0x8D = 5,
016,456,510,113,118,655,434,598,811,035,278,955,030,765,345,404,790,
744,303,017,523,831,112,055,108,147,451,509,157,692,220,295,382,716,
162,651,878,526,895,249,385,292,291,816,524,375,083,746,691,371,804,
094,271,873,160,484,737,966,720,260,389,217,684,476,157,468,082,573 =
0x0000000000000000 0000000000000000 0000000000000000 0000000000000000
0000000000000000 0000010000000000 0000000000000000 0000000000000000
0000000000000000 0000000000000000 0000000000000000 0000000000000000
0000000000000000 0000000000000000 0000000000000000 000000000000018D
The FNV offset_basis values are as follows:
32 bit offset_basis = 2,166,136,261 = 0x811C9DC5
64 bit offset_basis = 14695981039346656037 = 0xCBF29CE4 84222325
128 bit offset_basis = 144066263297769815596495629667062367629 =
0x6C62272E 07BB0142 62B82175 6295C58D
256 bit offset_basis = 100,029,257,958,052,580,907,070,968,
620,625,704,837,092,796,014,241,193,945,225,284,501,741,471,925,557 =
0xDD268DBCAAC55036 2D98C384C4E576CC C8B1536847B6BBB3 1023B4C8CAEE0535
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512 bit offset_basis = 9,
659,303,129,496,669,498,009,435,400,716,310,466,090,418,745,672,637,
896,108,374,329,434,462,657,994,582,932,197,716,438,449,813,051,892,
206,539,805,784,495,328,239,340,083,876,191,928,701,583,869,517,785 =
0xB86DB0B1171F4416 DCA1E50F309990AC AC87D059C9000000 0000000000000D21
E948F68A34C192F6 2EA79BC942DBE7CE 182036415F56E34B AC982AAC4AFE9FD9
1024 bit offset_basis = 14,197,795,064,947,621,068,722,070,641,403,
218,320,880,622,795,441,933,960,878,474,914,617,582,723,252,296,732,
303,717,722,150,864,096,521,202,355,549,365,628,174,669,108,571,814,
760,471,015,076,148,029,755,969,804,077,320,157,692,458,563,003,215,
304,957,150,157,403,644,460,363,550,505,412,711,285,966,361,610,267,
868,082,893,823,963,790,439,336,411,086,884,584,107,735,010,676,915 =
0x0000000000000000 005F7A76758ECC4D 32E56D5A591028B7 4B29FC4223FDADA1
6C3BF34EDA3674DA 9A21D90000000000 0000000000000000 0000000000000000
0000000000000000 0000000000000000 0000000000000000 000000000004C6D7
EB6E73802734510A 555F256CC005AE55 6BDE8CC9C6A93B21 AFF4B16C71EE90B3
G. Fowler, L. Noll, K. Vo, et. al [Page 10]
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6. The Source Code
[THIS CODE IS BEING WORKING AND IS INCONSISTENT AS BELOW.]
The following sub-sections provide reference C source code and a test
driver for FNV-1a.
Alternative source code, including 32 and 64 bit FNV-1 and FNV-1a in
x86 assembler, is currently available at [FNV].
Section 6.2 provides a test driver.
6.1 FNV-1a C Code
This section provides the direct FNV-1a function for each of the
lengths for which it is specified in this document. The functions
provided are listed below. Those whose name is of the form FNVxxxB*
output a byte vector that will be compatible between systems of
different endian-ness, where xxx is "32", "64", "128", "256", "512",
or "1024". Those whose name is of the form FNVxxx* (with no "B" after
the xxx) return an integer and are NOT compatible between systems of
different endian-ness. These integer based functions exist only for
xxx of "32" and, on systems supporting 64-bit integers, "64".
FNVxxxstring, FNVxxxblock:
FNVxxxBstring, FNVxxxBblock: These are simple functions for directly
returning the FNV hash of a zero terminated byte string not
including the zero and the FNV hash of a counted block of
bytes. Note that for applications of FNV-32 where 32-bit
integers are supported and FNV-64 where 64-bit integers are
supported and an integer data type output is acceptable, the
code is sufficiently simple that, to maximize performance, use
of open coding or macros may be more appropriate than calling a
subroutine.
FNVxxxinit, FNVxxxinitBasis:
FNVxxxBinit, FNVxxxBinitBasis: These functions and the next two sets
of functions below provide facilities for incrementally
calculating FNV hashes. They all assume a data structure of
type FNVxxx(B)context that holds the current state of the hash.
FNVxxx(B)init initializes that context to the standard
offset_basis. FNVxxx(B)initBasis takes an offset_basis value as
a parameter and may be useful for hashing concatenations, as
described in Section 4, as well as for simply using a non-
standard offset_basis.
G. Fowler, L. Noll, K. Vo, et. al [Page 11]
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FNVxxxblockin, FNVxxxstringin:
FNVxxxBblockin, FNVxxxBstringin: These functions hash a sequence of
bytes into an FNVxxx(B)context that was originally initialized
by FNVxxx(B)init or FNVxxx(B)initBasis. FNVxxx(B)blockin hashes
in a counted block of bytes. FNVxxx(B)stringin hashes in a zero
terminated byte string not incuding the final zero.
FNVxxxresult:
FNVxxxBresult: This function extracts the final FNV hash result from
an FNVxxx(B)context.
The following code is a private header file used by all the FNV
functions further below and which states the terms for use and
redistribution of all of this code.
<CODE BEGINS>
/************************ fnv-private.h ************************/
/****************** See RFC NNNN for details *******************/
/* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of Internet Society, IETF or IETF Trust, nor the
* names of specific contributors, may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
G. Fowler, L. Noll, K. Vo, et. al [Page 12]
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*/
#ifndef _FNV_PRIVATE_H_
#define _FNV_PRIVATE_H_
/*
* Six FNV-1a hashes are defined with these sizes:
* FNV32 32 bits, 4 bytes
* FNV64 64 bits, 8 bytes
* FNV128 128 bits, 16 bytes
* FNV256 256 bits, 32 bytes
* FNV512 512 bits, 64 bytes
* FNV1024 1024 bits, 128 bytes
*/
/* Private stuff used by this implementation of the FNV
* (Fowler, Noll, Vo) non-cryptographic hash function FNV-1a.
* External callers don't need to know any of this. */
enum { /* State value bases for context->Computed */
FNVinited = 22,
FNVcomputed = 76,
FNVemptied = 220,
FNVclobber = 122 /* known bad value for testing */
};
/* Deltas to assure distinct state values for different lengths */
enum {
FNV32state = 1,
FNV32Bstate = 17,
FNV64state = 3,
FNV64Bstate = 19,
FNV128state = 5,
FNV256state = 7,
FNV512state = 11,
FNV1024state = 13
};
#endif
<CODE ENDS>
The following code is a simple header file to include all the
specific length FNV header files.
<CODE BEGINS>
/****************************** FNV.h *******************************/
/******************* See RFC NNNN for details. **********************/
/*
* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
G. Fowler, L. Noll, K. Vo, et. al [Page 13]
INTERNET-DRAFT FNV
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV_H_
#define _FNV_H_
#include "FNV32.h"
#include "FNV32B.h"
#ifdef FNV_64bitIntegers
# include "FNV64.h"
#endif /* FNV_64bitIntegers */
#include "FNV64B.h"
#include "FNV128.h"
#include "FNV256.h"
#include "FNV512.h"
#include "FNV1024.h"
#endif /* _FNV_H_ */
<CODE ENDS>
The following code is a simple header file to control configuration
related to big integer and big endian support.
<CODE BEGINS>
/*************************** FNVconfig.h ****************************/
/******************* See RFC NNNN for details. **********************/
/*
* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNVconfig_H_
#define _FNVconfig_H_
/*
* Description:
* This file provides configuration ifdefs for the
* FNV-1a non-cryptographic hash algorithms.
*
* >>>>>>>> IMPORTANT CONFIGURATION ifdefs: <<<<<<<<<< */
/* FNV_64bitIntegers - Define this if your system supports 64-bit
* arithmetic including 32-bit x 32-bit multiplication
* producing a 64-bit product. If undefined, it will be
* assumed that 32-bit arithmetic is supported including
* 16-bit x 16-bit multiplication producing a 32-bit result.
*/
// #define FNV_64bitIntegers
G. Fowler, L. Noll, K. Vo, et. al [Page 14]
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/*
* The following allow the FNV test program to override the
* above configuration settings.
*/
#ifdef FNV_TEST_PROGRAM
# ifdef TEST_FNV_64bitIntegers
# ifndef FNV_64bitIntegers
# define FNV_64bitIntegers
# endif
# else
# undef FNV_64bitIntegers
# endif
# ifndef FNV_64bitIntegers /* causes an error if uint64_t is used */
# define uint64_t foobar /* RFC 3092 */
# endif
#endif
#endif /* _FNVconfig_H_ */
<CODE ENDS>
6.1.1 FNV32 Code
The header and C source for 32-bit FNV-1a returning a 32-bit integer.
<CODE BEGINS>
/***************************** FNV32.h ******************************/
/******************** See RFC NNNN for details **********************/
/*
* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV32_H_
#define _FNV32_H_
#include "FNVconfig.h"
#include <stdint.h>
/* #define FNV32size (32/8) not used */
/* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following types:
*
* type meaning
* uint32_t unsigned 32 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
G. Fowler, L. Noll, K. Vo, et. al [Page 15]
INTERNET-DRAFT FNV
*/
#ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_
/********************************************************************
* All FNV functions provided return as integer as follows:
* 0 -> success
* >0 -> error as listed below
*/
enum { /* success and errors */
fnvSuccess = 0,
fnvNull, /* Null pointer parameter */
fnvStateError, /* called Input after Result, etc. */
fnvBadParam /* passed a bad parameter */
};
#endif /* _FNV_ErrCodes_ */
/*
* This structure holds context information for an FNV32 hash
*/
typedef struct FNV32context_s {
int Computed; /* state */
uint32_t Hash;
} FNV32context;
/*
* Function Prototypes
* FNV32string: hash a zero terminated string not including
* the terminating zero
* FNV32block: hash a specified length byte vector
* FNV32init: initializes an FNV32 context
* FNV32initBasis: initializes an FNV32 context with a
* provided basis
* FNV32blockin: hash in a specified length byte vector
* FNV32stringin: hash in a zero terminated string not
* including the zero
* FNV32result: returns the hash value
*
* Hash is returned as a 32-bit integer
*/
#ifdef __cplusplus
extern "C" {
#endif
/* FNV32 */
extern int FNV32string ( const char *in,
uint32_t * const out );
extern int FNV32block ( const void *in,
long int inlength,
G. Fowler, L. Noll, K. Vo, et. al [Page 16]
INTERNET-DRAFT FNV
uint32_t * const out );
extern int FNV32init ( FNV32context * const );
extern int FNV32initBasis ( FNV32context * const,
uint32_t basis );
extern int FNV32blockin ( FNV32context * const,
const void *in,
long int inlength );
extern int FNV32stringin ( FNV32context * const,
const char *in );
extern int FNV32result ( FNV32context * const,
uint32_t * const out );
#ifdef __cplusplus
}
#endif
#endif /* _FNV32_H_ */
<CODE ENDS>
<CODE BEGINS>
/**************************** FNV32.c ****************************/
/****************** See RFC NNNN for details. ********************/
/* Copyright (c) 2016, 2017 IETF Trust and the persons identified
* as authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
/* This code implements the FNV (Fowler, Noll, Vo) non-cryptographic
* hash function FNV-1a for 32-bit hashes returning a 32-bit
* integer.
*/
#ifndef _FNV32_C_
#define _FNV32_C_
#include "fnv-private.h"
#include "FNV32.h"
/* 32 bit FNV_prime = 2^24 + 2^8 + 0x93 */
#define FNV32prime 0x01000193
#define FNV32basis 0x811C9DC5
/* FNV32 hash a zero terminated string not including the zero
*********************************************************************/
int FNV32string ( const char *in, uint32_t * const out )
{
uint32_t temp;
uint8_t ch;
if ( in && out )
G. Fowler, L. Noll, K. Vo, et. al [Page 17]
INTERNET-DRAFT FNV
{
temp = FNV32basis;
while ( (ch = *in++) )
temp = FNV32prime * ( temp ^ ch );
*out = temp;
return fnvSuccess;
}
return fnvNull; /* Null input pointer */
} /* end FNV32string */
/* FNV32 hash a counted block
***************************************************************/
int FNV32block ( const void *vin,
long int length,
uint32_t * const out )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp;
if ( in && out )
{
if ( length < 0 )
return fnvBadParam;
for ( temp = FNV32basis; length > 0; length-- )
temp = FNV32prime * ( temp ^ *in++ );
*out = temp;
return fnvSuccess;
}
return fnvNull; /* Null input pointer */
} /* end FNV32block */
/***************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV32 *
***************************************************************/
/* initialize context
***************************************************************/
int FNV32init ( FNV32context * const ctx )
{
return FNV32initBasis ( ctx, FNV32basis );
} /* end FNV32init */
/* initialize context with a provided basis
***************************************************************/
int FNV32initBasis ( FNV32context * const ctx, uint32_t basis )
{
if ( ctx )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 18]
INTERNET-DRAFT FNV
ctx->Hash = basis;
ctx->Computed = FNVinited+FNV32state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV32initBasis */
/* hash in a counted block
***************************************************************/
int FNV32blockin ( FNV32context * const ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV32state:
ctx->Computed = FNVcomputed+FNV32state;
case FNVcomputed+FNV32state:
break;
default:
return fnvStateError;
}
for ( temp = ctx->Hash; length > 0; length-- )
temp = FNV32prime * ( temp ^ *in++ );
ctx->Hash = temp;
return fnvSuccess;
}
return fnvNull;
} /* end FNV32blockin */
/* hash in a zero terminated string not including the zero
***************************************************************/
int FNV32stringin ( FNV32context * const ctx,
const char *in )
{
uint32_t temp;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV32state:
G. Fowler, L. Noll, K. Vo, et. al [Page 19]
INTERNET-DRAFT FNV
ctx->Computed = FNVcomputed+FNV32state;
case FNVcomputed+FNV32state:
break;
default:
return fnvStateError;
}
temp = ctx->Hash;
while ( (ch = (uint8_t)*in++) )
temp = FNV32prime * ( temp ^ ch );
ctx->Hash = temp;
return fnvSuccess;
}
return fnvNull;
} /* end FNV32stringin */
/* return hash
***************************************************************/
int FNV32result ( FNV32context * const ctx,
uint32_t * const out )
{
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV32state )
return fnvStateError;
ctx->Computed = FNVemptied+FNV32state;
*out = ctx->Hash;
ctx->Hash = 0;
return fnvSuccess;
}
return fnvNull;
} /* end FNV32result */
#endif /* _FNV32_C_ */
<CODE ENDS>
The header and C source for 32-bit FNV-1a returning a byte vector.
<CODE BEGINS>
/***************************** FNV32B.h *****************************/
/******************** See RFC NNNN for details **********************/
/*
* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV32_H_
#define _FNV32_H_
#include "FNVconfig.h"
G. Fowler, L. Noll, K. Vo, et. al [Page 20]
INTERNET-DRAFT FNV
#include <stdint.h>
#define FNV32size (32/8)
/* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following types:
*
* type meaning
* uint32_t unsigned 32 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
*/
#ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_
/********************************************************************
* All FNV functions provided return as integer as follows:
* 0 -> success
* >0 -> error as listed below
*/
enum { /* success and errors */
fnvSuccess = 0,
fnvNull, /* Null pointer parameter */
fnvStateError, /* called Input after Result, etc. */
fnvBadParam /* passed a bad parameter */
};
#endif /* _FNV_ErrCodes_ */
/*
* This structure holds context information for an FNV32 hash
*/
typedef struct FNV32Bcontext_s {
int Computed; /* state */
uint32_t Hash;
} FNV32Bcontext;
/*
* Function Prototypes
* FNV32Bstring: hash a zero terminated string not including
* the terminating zero
* FNV32Bblock: hash a specified length byte vector
* FNV32Binit: initializes an FNV32 context
* FNV32BinitBasis: initializes an FNV32 context with a
* provided basis
* FNV32Bblockin: hash in a specified length byte vector
* FNV32Bstringin: hash in a zero terminated string not
* including the zero
* FNV32Bresult: returns the hash value
*
* Hash is returned as a 32-bit integer
*/
G. Fowler, L. Noll, K. Vo, et. al [Page 21]
INTERNET-DRAFT FNV
#ifdef __cplusplus
extern "C" {
#endif
/* FNV32 */
extern int FNV32Bstring ( const char *in,
uint8_t * const out[FNV32size] );
extern int FNV32Bblock ( const void *in,
long int inlength,
uint8_t * const out[FNV32size] );
extern int FNV32Binit ( FNV32Bcontext * const );
extern int FNV32BinitBasis ( FNV32Bcontext * const,
uint32_t basis );
extern int FNV32Bblockin ( FNV32Bcontext * const,
const void *in,
long int inlength );
extern int FNV32Bstringin ( FNV32Bcontext * const,
const char *in );
extern int FNV32Bresult ( FNV32Bcontext * const,
int8_t * const out[FNV32size] );
#ifdef __cplusplus
}
#endif
#endif /* _FNV32_H_ */
<CODE ENDS>
<CODE BEGINS>
/**************************** FNV32B.c ***************************/
/****************** See RFC NNNN for details. ********************/
/* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
/* This code implements the FNV (Fowler, Noll, Vo) non-cryptographic
* hash function FNV-1a for 32-bit hashes returning a byte vector.
*/
#ifndef _FNV32_C_
#define _FNV32_C_
#include "fnv-private.h"
#include "FNV32B.h"
/* 32 bit FNV_prime = 2^24 + 2^8 + 0x93 */
#define FNV32prime 0x01000193
#define FNV32basis 0x811C9DC5
G. Fowler, L. Noll, K. Vo, et. al [Page 22]
INTERNET-DRAFT FNV
/* FNV32 hash a zero terminated string not including the zero
*******************************************************************/
int FNV32Bstring ( const char *in, uint8_t * const out[FNV32size] )
{
uint32_t temp;
uint8_t ch;
if ( in && out )
{
temp = FNV32basis;
while ( (ch = *in++) )
temp = FNV32prime * ( temp ^ ch );
*out[0] = temp & 0xFF;
temp =>> 8;
*out[1] = temp & 0xFF;
temp =>> 8;
*out[2] = temp & 0xFF;
temp =>> 8;
*out[3] = temp & 0xFF;
return fnvSuccess;
}
return fnvNull; /* Null input pointer */
} /* end FNV32Bstring */
/* FNV32 hash a counted block
***************************************************************/
int FNV32Bblock ( const void *vin,
long int length,
uint8_t * const out[FNV32size] )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp;
if ( in && out )
{
if ( length < 0 )
return fnvBadParam;
for ( temp = FNV32basis; length > 0; length-- )
temp = FNV32prime * ( temp ^ *in++ );
*out[0] = temp & 0xFF;
temp =>> 8;
*out[1] = temp & 0xFF;
temp =>> 8;
*out[2] = temp & 0xFF;
temp =>> 8;
*out[3] = temp & 0xFF;
*out = temp;
return fnvSuccess;
}
return fnvNull; /* Null input pointer */
G. Fowler, L. Noll, K. Vo, et. al [Page 23]
INTERNET-DRAFT FNV
} /* end FNV32Bblock */
/***************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV32 *
***************************************************************/
/* initialize context
***************************************************************/
int FNV32Binit ( FNV32Bcontext * const ctx )
{
return FNV32BinitBasis ( ctx, FNV32basis );
} /* end FNV32Binit */
/* initialize context with a provided basis
***************************************************************/
int FNV32BinitBasis ( FNV32Bcontext * const ctx, uint32_t basis )
{
if ( ctx )
{
ctx->Hash = basis;
ctx->Computed = FNVinited+FNV32Bstate;
return fnvSuccess;
}
return fnvNull;
} /* end FNV32BinitBasis */
/* hash in a counted block
***************************************************************/
int FNV32Bblockin ( FNV32Bcontext * const ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV32Bstate:
ctx->Computed = FNVcomputed+FNV32Bstate;
case FNVcomputed+FNV32Bstate:
break;
default:
return fnvStateError;
}
G. Fowler, L. Noll, K. Vo, et. al [Page 24]
INTERNET-DRAFT FNV
for ( temp = ctx->Hash; length > 0; length-- )
temp = FNV32prime * ( temp ^ *in++ );
ctx->Hash = temp;
return fnvSuccess;
}
return fnvNull;
} /* end FNV32Bblockin */
/* hash in a zero terminated string not including the zero
***************************************************************/
int FNV32Bstringin ( FNV32Bcontext * const ctx,
const char *in )
{
uint32_t temp;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV32Bstate:
ctx->Computed = FNVcomputed+FNV32Bstate;
case FNVcomputed+FNV32Bstate:
break;
default:
return fnvStateError;
}
temp = ctx->Hash;
while ( (ch = (uint8_t)*in++) )
temp = FNV32prime * ( temp ^ ch );
ctx->Hash = temp;
return fnvSuccess;
}
return fnvNull;
} /* end FNV32Bstringin */
/* return hash
***************************************************************/
int FNV32Bresult ( FNV32Bcontext * const ctx,
uint8_t * const out[FNV32size] )
{
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV32Bstate )
return fnvStateError;
ctx->Computed = FNVemptied+FNV32Bstate;
*out[0] = ctx->Hash & 0xFF;
ctx->Hash =>> 8;
*out[1] = ctx->Hash & 0xFF;
ctx->Hash =>> 8;
G. Fowler, L. Noll, K. Vo, et. al [Page 25]
INTERNET-DRAFT FNV
*out[2] = ctx->Hash & 0xFF;
ctx->Hash =>> 8;
*out[3] = ctx->Hash & 0xFF;
ctx->Hash = 0;
return fnvSuccess;
}
return fnvNull;
} /* end FNV32Bresult */
#endif /* _FNV32_C_ */
<CODE ENDS>
6.1.2 FNV64 C Code
The header and C source for 64-bit FNV-1a returning a 64-bit integer.
<CODE BEGINS>
/***************************** FNV64.h ******************************/
/******************* See RFC NNNN for details. **********************/
/*
* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV64_H_
#define _FNV64_H_
/*
* Description:
* This file provides headers for the 64-bit version of the FNV-1a
* non-cryptographic hash algorithm.
*/
#include "FNVconfig.h"
#include <stdint.h>
#define FNV64size (64/8)
/* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following types:
*
* type meaning
* uint64_t unsigned 64 bit integer (ifdef FNV_64bitIntegers)
* uint32_t unsigned 32 bit integer
* uint16_t unsigned 16 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
*/
G. Fowler, L. Noll, K. Vo, et. al [Page 26]
INTERNET-DRAFT FNV
#ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_
/*********************************************************************
* All FNV functions provided return as integer as follows:
* 0 -> success
* >0 -> error as listed below
*/
enum { /* success and errors */
fnvSuccess = 0,
fnvNull, /* Null pointer parameter */
fnvStateError, /* called Input after Result, etc. */
fnvBadParam /* passed a bad parameter */
};
#endif /* _FNV_ErrCodes_ */
/*
* This structure holds context information for an FNV64 hash
*/
#ifdef FNV_64bitIntegers
/* version if 64 bit integers supported */
typedef struct FNV64context_s {
int Computed; /* state */
uint64_t Hash;
} FNV64context;
#else
/* version if 64 bit integers NOT supported */
typedef struct FNV64context_s {
int Computed; /* state */
uint16_t Hash[FNV64size/2];
} FNV64context;
#endif /* FNV_64bitIntegers */
/*
* Function Prototypes
* FNV64string: hash a zero terminated string not including
* the terminating zero
* FNV64block: FNV64 hash a specified length byte vector
* FNV64init: initializes an FNV64 context
* FNV64initBasis: initializes an FNV64 context with a
* provided basis
* FNV64blockin: hash in a specified length byte vector
* FNV64stringin: hash in a zero terminated string not
* incluing the zero
* FNV64result: returns the hash value
*
* Hash is returned as a 64-bit integer if supported, otherwise
G. Fowler, L. Noll, K. Vo, et. al [Page 27]
INTERNET-DRAFT FNV
* as a vector of 8-bit integers
*/
#ifdef __cplusplus
extern "C" {
#endif
/* FNV64 */
extern int FNV64init ( FNV64context * const );
extern int FNV64blockin ( FNV64context * const,
const void * in,
long int length );
extern int FNV64stringin ( FNV64context * const,
const char * in );
#ifdef FNV_64bitIntegers
extern int FNV64string ( const char *in,
uint64_t * const out );
extern int FNV64block ( const void *in,
long int length,
uint64_t * const out );
extern int FNV64initBasis ( FNV64context * const,
uint64_t basis );
extern int FNV64result ( FNV64context * const,
uint64_t * const out );
#else
extern int FNV64string ( const char *in,
uint8_t out[FNV64size] );
extern int FNV64block ( const void *in,
long int length,
uint8_t out[FNV64size] );
extern int FNV64initBasis ( FNV64context * const,
const uint8_t basis[FNV64size] );
extern int FNV64result ( FNV64context * const,
uint8_t out[FNV64size] );
#endif /* FNV_64bitIntegers */
#ifdef __cplusplus
}
#endif
#endif /* _FNV64_H_ */
<CODE ENDS>
<CODE BEGINS>
/***************************** FNV64.c ******************************/
/******************** See RFC NNNN for details **********************/
/* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
G. Fowler, L. Noll, K. Vo, et. al [Page 28]
INTERNET-DRAFT FNV
*/
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic
* hash function FNV-1a for 64-bit hashes.
*/
#ifndef _FNV64_C_
#define _FNV64_C_
#include "fnv-private.h"
#include "FNV64.h"
/********************************************************************
* START VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
********************************************************************/
#ifdef FNV_64bitIntegers
/* 64 bit FNV_prime = 2^40 + 2^8 + 0xb3 */
#define FNV64prime 0x00000100000001B3
#define FNV64basis 0xCBF29CE484222325
/* FNV64 hash a null terminated string (64 bit)
********************************************************************/
int FNV64string ( const char *in, uint64_t * const out )
{
uint64_t temp;
uint8_t ch;
if ( in && out )
{
temp = FNV64basis;
while ( (ch = *in++) )
temp = FNV64prime * ( temp ^ ch );
#ifdef FNV_BigEndian
FNV64reverse ( out, temp );
#else
*out = temp;
#endif
return fnvSuccess;
}
return fnvNull; /* Null input pointer */
} /* end FNV64string */
/* FNV64 hash a counted block (64 bit)
********************************************************************/
int FNV64block ( const void *vin,
long int length,
uint64_t * const out )
{
const uint8_t *in = (const uint8_t*)vin;
G. Fowler, L. Noll, K. Vo, et. al [Page 29]
INTERNET-DRAFT FNV
uint64_t temp;
if ( in && out )
{
if ( length < 0 )
return fnvBadParam;
for ( temp = FNV64basis; length > 0; length-- )
temp = FNV64prime * ( temp ^ *in++ );
#ifdef FNV_BigEndian
FNV64reverse ( out, temp );
#else
*out = temp;
#endif
return fnvSuccess;
}
return fnvNull; /* Null input pointer */
} /* end FNV64block */
#ifdef FNV_BigEndian
/* Store a Big Endian result back as Little Endian
***************************************************************/
static void FNV64reverse ( uint64_t *out, uint64_t hash )
{
uint64_t temp;
int i;
temp = hash & 0xFF;
for ( i = FNV64size - 1; i > 0; i-- )
{
hash >>= 8;
temp = ( temp << 8 ) + ( hash & 0xFF );
}
*out = temp;
} /* end FNV64reverse */
#endif /* FNV_BigEndian */
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV64 *
********************************************************************/
/* initialize context (64 bit)
********************************************************************/
int FNV64init ( FNV64context * const ctx )
{
return FNV64initBasis ( ctx, FNV64basis );
} /* end FNV64init */
G. Fowler, L. Noll, K. Vo, et. al [Page 30]
INTERNET-DRAFT FNV
/* initialize context with a provided basis (64 bit)
********************************************************************/
int FNV64initBasis ( FNV64context * const ctx, uint64_t basis )
{
if ( ctx )
{
ctx->Hash = basis;
ctx->Computed = FNVinited+FNV64state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64initBasis */
/* hash in a counted block (64 bit)
********************************************************************/
int FNV64blockin ( FNV64context * const ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint64_t temp;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV64state:
ctx->Computed = FNVcomputed+FNV64state;
case FNVcomputed+FNV64state:
break;
default:
return fnvStateError;
}
for ( temp = ctx->Hash; length > 0; length-- )
temp = FNV64prime * ( temp ^ *in++ );
ctx->Hash = temp;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64input */
/* hash in a zero terminated string not including the zero (64 bit)
********************************************************************/
int FNV64stringin ( FNV64context * const ctx,
const char *in )
{
uint64_t temp;
uint8_t ch;
G. Fowler, L. Noll, K. Vo, et. al [Page 31]
INTERNET-DRAFT FNV
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV64state:
ctx->Computed = FNVcomputed+FNV64state;
case FNVcomputed+FNV64state:
break;
default:
return fnvStateError;
}
temp = ctx->Hash;
while ( (ch = *in++) )
temp = FNV64prime * ( temp ^ ch );
ctx->Hash = temp;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64stringin */
/* return hash (64 bit)
********************************************************************/
int FNV64result ( FNV64context * const ctx,
uint64_t * const out )
{
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV64state )
return fnvStateError;
ctx->Computed = FNVemptied+FNV64state;
#ifdef FNV_BigEndian
FNV64reverse ( out, ctx->Hash );
#else
*out = ctx->Hash;
#endif
ctx->Hash = 0;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64result */
/******************************************************************
* END VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
******************************************************************/
#else /* FNV_64bitIntegers */
/******************************************************************
* START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
******************************************************************/
/* 64 bit FNV_prime = 2^40 + 2^8 + 0xb3 */
G. Fowler, L. Noll, K. Vo, et. al [Page 32]
INTERNET-DRAFT FNV
/* #define FNV64prime 0x00000100000001B3 */
#define FNV64primeX 0x01B3
#define FNV64shift 8
/* #define FNV64basis 0xCBF29CE484222325 */
#define FNV64basis0 0xCBF2
#define FNV64basis1 0x9CE4
#define FNV64basis2 0x8422
#define FNV64basis3 0x2325
/* FNV64 hash a null terminated string (32 bit)
********************************************************************/
int FNV64string ( const char *in, uint8_t out[FNV64size] )
{
FNV64context ctx;
int err;
if ( ( err = FNV64init (&ctx) ) != fnvSuccess )
return err;
if ( ( err = FNV64stringin (&ctx, in) ) != fnvSuccess )
return err;
return FNV64result (&ctx, out);
} /* end FNV64string */
/* FNV64 hash a counted block (32 bit)
********************************************************************/
int FNV64block ( const void *in,
long int length,
uint8_t out[FNV64size] )
{
FNV64context ctx;
int err;
if ( ( err = FNV64init (&ctx) ) != fnvSuccess )
return err;
if ( ( err = FNV64blockin (&ctx, in, length) ) != fnvSuccess )
return err;
return FNV64result (&ctx, out);
} /* end FNV64block */
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV64 *
********************************************************************/
/* initialize context (32 bit)
********************************************************************/
int FNV64init ( FNV64context * const ctx )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 33]
INTERNET-DRAFT FNV
if ( ctx )
{
ctx->Hash[0] = FNV64basis0;
ctx->Hash[1] = FNV64basis1;
ctx->Hash[2] = FNV64basis2;
ctx->Hash[3] = FNV64basis3;
ctx->Computed = FNVinited+FNV64state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64init */
/* initialize context (32 bit)
********************************************************************/
int FNV64initBasis ( FNV64context * const ctx,
const uint8_t basis[FNV64size] )
{
if ( ctx )
{
#ifdef FNV_BigEndian
ctx->Hash[0] = basis[1] + ( basis[0]<<8 );
ctx->Hash[1] = basis[3] + ( basis[2]<<8 );
ctx->Hash[2] = basis[5] + ( basis[4]<<8 );
ctx->Hash[3] = basis[7] + ( basis[6]<<8 );
#else
ctx->Hash[0] = basis[0] + ( basis[1]<<8 );
ctx->Hash[1] = basis[2] + ( basis[3]<<8 );
ctx->Hash[2] = basis[4] + ( basis[5]<<8 );
ctx->Hash[3] = basis[6] + ( basis[7]<<8 );
#endif
ctx->Computed = FNVinited+FNV64state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64initBasis */
/* hash in a counted block (32 bit)
********************************************************************/
int FNV64blockin ( FNV64context * const ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp[FNV64size/2];
uint32_t temp2[2];
int i;
if ( ctx && in )
{
if ( length < 0 )
G. Fowler, L. Noll, K. Vo, et. al [Page 34]
INTERNET-DRAFT FNV
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV64state:
ctx->Computed = FNVcomputed+FNV64state;
case FNVcomputed+FNV64state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV64size/2; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV64prime * ( temp ^ *in++ ); */
temp2[1] = temp[3] << FNV64shift;
temp2[0] = temp[2] << FNV64shift;
temp[3] = FNV64primeX * ( temp[3] ^ *in++ );
temp[2] *= FNV64primeX;
temp[1] = temp[1] * FNV64primeX + temp2[1];
temp[0] = temp[0] * FNV64primeX + temp2[0];
temp[2] += temp[3] >> 16;
temp[3] &= 0xFFFF;
temp[1] += temp[2] >> 16;
temp[2] &= 0xFFFF;
temp[0] += temp[1] >> 16;
temp[1] &= 0xFFFF;
}
for ( i=0; i<FNV64size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV64blockin */
/* hash in a string (32 bit)
********************************************************************/
int FNV64stringin ( FNV64context * const ctx,
const char *in )
{
uint32_t temp[FNV64size/2];
uint32_t temp2[2];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV64state:
G. Fowler, L. Noll, K. Vo, et. al [Page 35]
INTERNET-DRAFT FNV
ctx->Computed = FNVcomputed+FNV64state;
case FNVcomputed+FNV64state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV64size/2; ++i )
temp[i] = ctx->Hash[i];
while ( ( ch = (uint8_t)*in++ ) != 0)
{
/* temp = FNV64prime * ( temp ^ ch ); */
temp2[1] = temp[3] << FNV64shift;
temp2[0] = temp[2] << FNV64shift;
temp[3] = FNV64primeX * ( temp[3] ^ *in++ );
temp[2] *= FNV64primeX;
temp[1] = temp[1] * FNV64primeX + temp2[1];
temp[0] = temp[0] * FNV64primeX + temp2[0];
temp[2] += temp[3] >> 16;
temp[3] &= 0xFFFF;
temp[1] += temp[2] >> 16;
temp[2] &= 0xFFFF;
temp[0] += temp[1] >> 16;
temp[1] &= 0xFFFF;
}
for ( i=0; i<FNV64size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV64stringin */
/* return hash (32 bit)
********************************************************************/
int FNV64result ( FNV64context * const ctx,
uint8_t out[FNV64size] )
{
int i;
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV64state )
return fnvStateError;
for ( i=0; i<FNV64size/2; ++i )
{
#ifdef FNV_BigEndian
out[7-2*i] = ctx->Hash[i];
out[6-2*i] = ctx->Hash[i] >> 8;
#else
out[2*i] = ctx->Hash[i];
out[2*i+1] = ctx->Hash[i] >> 8;
G. Fowler, L. Noll, K. Vo, et. al [Page 36]
INTERNET-DRAFT FNV
#endif
ctx -> Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV64state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64result */
#endif /* FNV_64bitIntegers */
/********************************************************************
* END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
********************************************************************/
#endif /* _FNV64_C_ */
<CODE ENDS>
The header and C source for 64-bit FNV-1a returning a byte vector.
<CODE BEGINS>
/***************************** FNV64B.h *****************************/
/******************* See RFC NNNN for details. **********************/
/*
* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV64_H_
#define _FNV64_H_
/*
* Description:
* This file provides headers for the 64-bit version of the FNV-1a
* non-cryptographic hash algorithm.
*/
#include "FNVconfig.h"
#include <stdint.h>
#define FNV64size (64/8)
/* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following types:
*
* type meaning
* uint64_t unsigned 64 bit integer (ifdef FNV_64bitIntegers)
* uint32_t unsigned 32 bit integer
* uint16_t unsigned 16 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
G. Fowler, L. Noll, K. Vo, et. al [Page 37]
INTERNET-DRAFT FNV
*/
#ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_
/*********************************************************************
* All FNV functions provided return as integer as follows:
* 0 -> success
* >0 -> error as listed below
*/
enum { /* success and errors */
fnvSuccess = 0,
fnvNull, /* Null pointer parameter */
fnvStateError, /* called Input after Result, etc. */
fnvBadParam /* passed a bad parameter */
};
#endif /* _FNV_ErrCodes_ */
/*
* This structure holds context information for an FNV64 hash
*/
#ifdef FNV_64bitIntegers
/* version if 64 bit integers supported */
typedef struct FNV64Bcontext_s {
int Computed; /* state */
uint64_t Hash;
} FNV64Bcontext;
#else
/* version if 64 bit integers NOT supported */
typedef struct FNV64Bcontext_s {
int Computed; /* state */
uint16_t Hash[FNV64size/2];
} FNV64Bcontext;
#endif /* FNV_64bitIntegers */
/*
* Function Prototypes
* FNV64Bstring: hash a zero terminated string not including
* the terminating zero
* FNV64Bblock: FNV64 hash a specified length byte vector
* FNV64Binit: initializes an FNV64 context
* FNV64BinitBasis: initializes an FNV64 context with a
* provided basis
* FNV64Bblockin: hash in a specified length byte vector
* FNV64Bstringin: hash in a zero terminated string not
* incluing the zero
* FNV64Bresult: returns the hash value
G. Fowler, L. Noll, K. Vo, et. al [Page 38]
INTERNET-DRAFT FNV
*
* Hash is returned as a vector of 8-bit integers
*/
#ifdef __cplusplus
extern "C" {
#endif
/* FNV64 */
extern int FNV64Bstring ( const char *in,
uint8_t out[FNV64size] );
extern int FNV64Bblock ( const void *in,
long int length,
uint8_t out[FNV64size] );
extern int FNV64Binit ( FNV64Bcontext * const );
extern int FNV64BinitBasis ( FNV64Bcontext * const,
const uint8_t basis[FNV64size] );
extern int FNV64Bblockin ( FNV64Bcontext * const,
const void * in,
long int length );
extern int FNV64Bstringin ( FNV64Bcontext * const,
const char * in );
extern int FNV64Bresult ( FNV64Bcontext * const,
uint8_t out[FNV64size] );
#ifdef __cplusplus
}
#endif
#endif /* _FNV64_H_ */
<CODE ENDS>
<CODE BEGINS>
/***************************** FNV64B.c *****************************/
/******************** See RFC NNNN for details **********************/
/* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic
* hash function FNV-1a for 64-bit hashes.
*/
#ifndef _FNV64_C_
#define _FNV64_C_
#include "fnv-private.h"
#include "FNV64.h"
G. Fowler, L. Noll, K. Vo, et. al [Page 39]
INTERNET-DRAFT FNV
/********************************************************************
* START VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
********************************************************************/
#ifdef FNV_64bitIntegers
/* 64 bit FNV_prime = 2^40 + 2^8 + 0xb3 */
#define FNV64prime 0x00000100000001B3
#define FNV64basis 0xCBF29CE484222325
/* FNV64 hash a null terminated string (64 bit)
********************************************************************/
int FNV64Bstring ( const char *in, uint64_t * const out )
{
uint64_t temp;
uint8_t ch;
if ( in && out )
{
temp = FNV64basis;
while ( (ch = *in++) )
temp = FNV64prime * ( temp ^ ch );
#ifdef FNV_BigEndian
FNV64reverse ( out, temp );
#else
*out = temp;
#endif
return fnvSuccess;
}
return fnvNull; /* Null input pointer */
} /* end FNV64string */
/* FNV64 hash a counted block (64 bit)
********************************************************************/
int FNV64Bblock ( const void *vin,
long int length,
uint64_t * const out )
{
const uint8_t *in = (const uint8_t*)vin;
uint64_t temp;
if ( in && out )
{
if ( length < 0 )
return fnvBadParam;
for ( temp = FNV64basis; length > 0; length-- )
temp = FNV64prime * ( temp ^ *in++ );
#ifdef FNV_BigEndian
FNV64reverse ( out, temp );
#else
*out = temp;
G. Fowler, L. Noll, K. Vo, et. al [Page 40]
INTERNET-DRAFT FNV
#endif
return fnvSuccess;
}
return fnvNull; /* Null input pointer */
} /* end FNV64block */
#ifdef FNV_BigEndian
/* Store a Big Endian result back as Little Endian
***************************************************************/
static void FNV64Breverse ( uint64_t *out, uint64_t hash )
{
uint64_t temp;
int i;
temp = hash & 0xFF;
for ( i = FNV64size - 1; i > 0; i-- )
{
hash >>= 8;
temp = ( temp << 8 ) + ( hash & 0xFF );
}
*out = temp;
} /* end FNV64reverse */
#endif /* FNV_BigEndian */
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV64 *
********************************************************************/
/* initialize context (64 bit)
********************************************************************/
int FNV64Binit ( FNV64Bcontext * const ctx )
{
return FNV64initBasis ( ctx, FNV64basis );
} /* end FNV64Binit */
/* initialize context with a provided basis (64 bit)
********************************************************************/
int FNV64BinitBasis ( FNV64Bcontext * const ctx, uint64_t basis )
{
if ( ctx )
{
ctx->Hash = basis;
ctx->Computed = FNVinited+FNV64state;
return fnvSuccess;
}
return fnvNull;
G. Fowler, L. Noll, K. Vo, et. al [Page 41]
INTERNET-DRAFT FNV
} /* end FNV64BinitBasis */
/* hash in a counted block (64 bit)
********************************************************************/
int FNV64Bblockin ( FNV64Bcontext * const ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint64_t temp;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV64state:
ctx->Computed = FNVcomputed+FNV64state;
case FNVcomputed+FNV64state:
break;
default:
return fnvStateError;
}
for ( temp = ctx->Hash; length > 0; length-- )
temp = FNV64prime * ( temp ^ *in++ );
ctx->Hash = temp;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64Binput */
/* hash in a zero terminated string not including the zero (64 bit)
********************************************************************/
int FNV64Bstringin ( FNV64Bcontext * const ctx,
const char *in )
{
uint64_t temp;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV64state:
ctx->Computed = FNVcomputed+FNV64state;
case FNVcomputed+FNV64state:
break;
default:
return fnvStateError;
G. Fowler, L. Noll, K. Vo, et. al [Page 42]
INTERNET-DRAFT FNV
}
temp = ctx->Hash;
while ( (ch = *in++) )
temp = FNV64prime * ( temp ^ ch );
ctx->Hash = temp;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64Bstringin */
/* return hash (64 bit)
********************************************************************/
int FNV64Bresult ( FNV64Bcontext * const ctx,
uint64_t * const out )
{
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV64state )
return fnvStateError;
ctx->Computed = FNVemptied+FNV64state;
#ifdef FNV_BigEndian
FNV64reverse ( out, ctx->Hash );
#else
*out = ctx->Hash;
#endif
ctx->Hash = 0;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64Bresult */
/******************************************************************
* END VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
******************************************************************/
#else /* FNV_64bitIntegers */
/******************************************************************
* START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
******************************************************************/
/* 64 bit FNV_prime = 2^40 + 2^8 + 0xb3 */
/* #define FNV64prime 0x00000100000001B3 */
#define FNV64primeX 0x01B3
#define FNV64shift 8
/* #define FNV64basis 0xCBF29CE484222325 */
#define FNV64basis0 0xCBF2
#define FNV64basis1 0x9CE4
#define FNV64basis2 0x8422
#define FNV64basis3 0x2325
G. Fowler, L. Noll, K. Vo, et. al [Page 43]
INTERNET-DRAFT FNV
/* FNV64 hash a null terminated string (32 bit)
********************************************************************/
int FNV64Bstring ( const char *in, uint8_t out[FNV64size] )
{
FNV64Bcontext ctx;
int err;
if ( ( err = FNV64init (&ctx) ) != fnvSuccess )
return err;
if ( ( err = FNV64stringin (&ctx, in) ) != fnvSuccess )
return err;
return FNV64result (&ctx, out);
} /* end FNV64Bstring */
/* FNV64 hash a counted block (32 bit)
********************************************************************/
int FNV64Bblock ( const void *in,
long int length,
uint8_t out[FNV64size] )
{
FNV64Bcontext ctx;
int err;
if ( ( err = FNV64init (&ctx) ) != fnvSuccess )
return err;
if ( ( err = FNV64blockin (&ctx, in, length) ) != fnvSuccess )
return err;
return FNV64result (&ctx, out);
} /* end FNV64Bblock */
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV64 *
********************************************************************/
/* initialize context (32 bit)
********************************************************************/
int FNV64Binit ( FNV64Bcontext * const ctx )
{
if ( ctx )
{
ctx->Hash[0] = FNV64basis0;
ctx->Hash[1] = FNV64basis1;
ctx->Hash[2] = FNV64basis2;
ctx->Hash[3] = FNV64basis3;
ctx->Computed = FNVinited+FNV64state;
return fnvSuccess;
}
return fnvNull;
G. Fowler, L. Noll, K. Vo, et. al [Page 44]
INTERNET-DRAFT FNV
} /* end FNV64Binit */
/* initialize context (32 bit)
********************************************************************/
int FNV64BinitBasis ( FNV64Bcontext * const ctx,
const uint8_t basis[FNV64size] )
{
if ( ctx )
{
#ifdef FNV_BigEndian
ctx->Hash[0] = basis[1] + ( basis[0]<<8 );
ctx->Hash[1] = basis[3] + ( basis[2]<<8 );
ctx->Hash[2] = basis[5] + ( basis[4]<<8 );
ctx->Hash[3] = basis[7] + ( basis[6]<<8 );
#else
ctx->Hash[0] = basis[0] + ( basis[1]<<8 );
ctx->Hash[1] = basis[2] + ( basis[3]<<8 );
ctx->Hash[2] = basis[4] + ( basis[5]<<8 );
ctx->Hash[3] = basis[6] + ( basis[7]<<8 );
#endif
ctx->Computed = FNVinited+FNV64state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64BinitBasis */
/* hash in a counted block (32 bit)
********************************************************************/
int FNV64Bblockin ( FNV64Bcontext * const ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp[FNV64size/2];
uint32_t temp2[2];
int i;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV64state:
ctx->Computed = FNVcomputed+FNV64state;
case FNVcomputed+FNV64state:
break;
default:
return fnvStateError;
}
G. Fowler, L. Noll, K. Vo, et. al [Page 45]
INTERNET-DRAFT FNV
for ( i=0; i<FNV64size/2; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV64prime * ( temp ^ *in++ ); */
temp2[1] = temp[3] << FNV64shift;
temp2[0] = temp[2] << FNV64shift;
temp[3] = FNV64primeX * ( temp[3] ^ *in++ );
temp[2] *= FNV64primeX;
temp[1] = temp[1] * FNV64primeX + temp2[1];
temp[0] = temp[0] * FNV64primeX + temp2[0];
temp[2] += temp[3] >> 16;
temp[3] &= 0xFFFF;
temp[1] += temp[2] >> 16;
temp[2] &= 0xFFFF;
temp[0] += temp[1] >> 16;
temp[1] &= 0xFFFF;
}
for ( i=0; i<FNV64size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV64Bblockin */
/* hash in a string (32 bit)
********************************************************************/
int FNV64Bstringin ( FNV64Bcontext * const ctx,
const char *in )
{
uint32_t temp[FNV64size/2];
uint32_t temp2[2];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV64state:
ctx->Computed = FNVcomputed+FNV64state;
case FNVcomputed+FNV64state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV64size/2; ++i )
temp[i] = ctx->Hash[i];
while ( ( ch = (uint8_t)*in++ ) != 0)
{
G. Fowler, L. Noll, K. Vo, et. al [Page 46]
INTERNET-DRAFT FNV
/* temp = FNV64prime * ( temp ^ ch ); */
temp2[1] = temp[3] << FNV64shift;
temp2[0] = temp[2] << FNV64shift;
temp[3] = FNV64primeX * ( temp[3] ^ *in++ );
temp[2] *= FNV64primeX;
temp[1] = temp[1] * FNV64primeX + temp2[1];
temp[0] = temp[0] * FNV64primeX + temp2[0];
temp[2] += temp[3] >> 16;
temp[3] &= 0xFFFF;
temp[1] += temp[2] >> 16;
temp[2] &= 0xFFFF;
temp[0] += temp[1] >> 16;
temp[1] &= 0xFFFF;
}
for ( i=0; i<FNV64size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV64Bstringin */
/* return hash (32 bit)
********************************************************************/
int FNV64Bresult ( FNV64Bcontext * const ctx,
uint8_t out[FNV64size] )
{
int i;
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV64state )
return fnvStateError;
for ( i=0; i<FNV64size/2; ++i )
{
#ifdef FNV_BigEndian
out[7-2*i] = ctx->Hash[i];
out[6-2*i] = ctx->Hash[i] >> 8;
#else
out[2*i] = ctx->Hash[i];
out[2*i+1] = ctx->Hash[i] >> 8;
#endif
ctx -> Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV64state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV64Bresult */
#endif /* FNV_64bitIntegers */
G. Fowler, L. Noll, K. Vo, et. al [Page 47]
INTERNET-DRAFT FNV
/********************************************************************
* END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
********************************************************************/
#endif /* _FNV64_C_ */
<CODE ENDS>
6.1.3 FNV128 C Code
The header and C source for 128-bit FNV-1a returning a byte vector.
<CODE BEGINS>
/**************************** FNV128.h **************************/
/***************** See RFC NNNN for details. ********************/
/*
* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV128_H_
#define _FNV128_H_
/*
* Description:
* This file provides headers for the 128-bit version of the
* FNV-1a non-cryptographic hash algorithm.
*/
#include "FNVconfig.h"
#include <stdint.h>
#define FNV128size (128/8)
/* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following types:
*
* type meaning
* uint64_t unsigned 64 bit integer (ifdef FNV_64bitIntegers)
* uint32_t unsigned 32 bit integer
* uint16_t unsigned 16 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
*/
#ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_
/*********************************************************************
* All FNV functions provided return as integer as follows:
G. Fowler, L. Noll, K. Vo, et. al [Page 48]
INTERNET-DRAFT FNV
* 0 -> success
* >0 -> error as listed below
*/
enum { /* success and errors */
fnvSuccess = 0,
fnvNull, /* Null pointer parameter */
fnvStateError, /* called Input after Result or before Init */
fnvBadParam /* passed a bad parameter */
};
#endif /* _FNV_ErrCodes_ */
/*
* This structure holds context information for an FNV128 hash
*/
#ifdef FNV_64bitIntegers
/* version if 64 bit integers supported */
typedef struct FNV128context_s {
int Computed; /* state */
uint32_t Hash[FNV128size/4];
} FNV128context;
#else
/* version if 64 bit integers NOT supported */
typedef struct FNV128context_s {
int Computed; /* state */
uint16_t Hash[FNV128size/2];
} FNV128context;
#endif /* FNV_64bitIntegers */
/*
* Function Prototypes
* FNV128string: hash a zero terminated string not including
* the terminating zero
* FNV128block: FNV128 hash a specified length byte vector
* FNV128init: initializes an FNV128 context
* FNV128initBasis: initializes an FNV128 context with a
* provided basis
* FNV128blockin: hash in a specified length byte vector
* FNV128stringin: hash in a zero terminated string not
* including the zero
* FNV128result: returns the hash value
*
* Hash is returned as an array of 8-bit integers
*/
#ifdef __cplusplus
extern "C" {
#endif
G. Fowler, L. Noll, K. Vo, et. al [Page 49]
INTERNET-DRAFT FNV
/* FNV128 */
extern int FNV128string ( const char *in,
uint8_t out[FNV128size] );
extern int FNV128block ( const void *in,
long int length,
uint8_t out[FNV128size] );
extern int FNV128init ( FNV128context * const );
extern int FNV128initBasis ( FNV128context * const,
const uint8_t basis[FNV128size] );
extern int FNV128blockin ( FNV128context * const,
const void *in,
long int length );
extern int FNV128stringin ( FNV128context * const,
const char *in );
extern int FNV128result ( FNV128context * const,
uint8_t out[FNV128size] );
#ifdef __cplusplus
}
#endif
#endif /* _FNV128_H_ */
<CODE ENDS>
<CODE BEGINS>
/***************************** FNV128.c ****************************/
/******************** See RFC NNNN for details *********************/
/* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights
* See fnv-private.h for terms of use and redistribution.
*/
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic
* hash function FNV-1a for 128-bit hashes.
*/
#ifndef _FNV128_C_
#define _FNV128_C_
#include "fnv-private.h"
#include "FNV128.h"
/* common code for 64 and 32 bit modes */
/* FNV128 hash a null terminated string (64/32 bit)
********************************************************************/
int FNV128string ( const char *in, uint8_t out[FNV128size] )
{
FNV128context ctx;
int err;
G. Fowler, L. Noll, K. Vo, et. al [Page 50]
INTERNET-DRAFT FNV
err = FNV128init ( &ctx );
if ( err != fnvSuccess ) return err;
err = FNV128stringin ( &ctx, in );
if ( err != fnvSuccess ) return err;
return FNV128result (&ctx, out);
} /* end FNV128string */
/* FNV128 hash a counted block (64/32 bit)
********************************************************************/
int FNV128block ( const void *in,
long int length,
uint8_t out[FNV128size] )
{
FNV128context ctx;
int err;
err = FNV128init ( &ctx );
if ( err != fnvSuccess ) return err;
err = FNV128blockin ( &ctx, in, length );
if ( err != fnvSuccess ) return err;
return FNV128result ( &ctx, out );
} /* end FNV128block */
/********************************************************************
* START VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
********************************************************************/
#ifdef FNV_64bitIntegers
/* 128 bit FNV_prime = 2^88 + 2^8 + 0x3b */
/* 0x00000000 01000000 00000000 0000013B */
#define FNV128primeX 0x013B
#define FNV128shift 24
/* 0x6C62272E 07BB0142 62B82175 6295C58D */
#define FNV128basis0 0x6C62272E
#define FNV128basis1 0x07BB0142
#define FNV128basis2 0x62B82175
#define FNV128basis3 0x6295C58D
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV128 *
********************************************************************/
/* initialize context (64 bit)
********************************************************************/
int FNV128init ( FNV128context * const ctx )
{
if ( ctx )
G. Fowler, L. Noll, K. Vo, et. al [Page 51]
INTERNET-DRAFT FNV
{
ctx->Hash[0] = FNV128basis0;
ctx->Hash[1] = FNV128basis1;
ctx->Hash[2] = FNV128basis2;
ctx->Hash[3] = FNV128basis3;
ctx->Computed = FNVinited+FNV128state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV128init */
/* initialize context with a provided basis (64 bit)
********************************************************************/
int FNV128initBasis ( FNV128context * const ctx,
const uint8_t basis[FNV128size] )
{
int i;
const uint8_t *ui8p;
uint32_t temp;
if ( ctx )
{
#ifdef FNV_BigEndian
ui8p = basis;
for ( i=0; i < FNV128size/4; ++i )
{
temp = (*ui8p++)<<8;
temp = (temp + *ui8p++)<<8;
temp = (temp + *ui8p++)<<8;
ctx->Hash[i] = temp + *ui8p;
}
#else
ui8p = basis + ( FNV128size/4 - 1 );
for ( i=0; i < FNV128size/4; ++i )
{
temp = (*ui8p--)<<8;
temp = (temp + *ui8p--)<<8;
temp = (temp + *ui8p--)<<8;
ctx->Hash[i] = temp + *ui8p;
}
#endif
ctx->Computed = FNVinited+FNV128state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV128initBasis */
/* hash in a counted block (64 bit)
********************************************************************/
int FNV128blockin ( FNV128context * const ctx,
G. Fowler, L. Noll, K. Vo, et. al [Page 52]
INTERNET-DRAFT FNV
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint64_t temp[FNV128size/4];
uint64_t temp2[2];
int i;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV128state:
ctx->Computed = FNVcomputed+FNV128state;
case FNVcomputed+FNV128state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV128size/4; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV128prime * ( temp ^ *in++ ); */
temp2[1] = temp[3] << FNV128shift;
temp2[0] = temp[2] << FNV128shift;
temp[3] = FNV128primeX * ( temp[3] ^ *in++ );
temp[2] *= FNV128primeX;
temp[1] = temp[1] * FNV128primeX + temp2[1];
temp[0] = temp[0] * FNV128primeX + temp2[0];
temp[2] += temp[3] >> 32;
temp[3] &= 0xFFFFFFFF;
temp[1] += temp[2] >> 32;
temp[2] &= 0xFFFFFFFF;
temp[0] += temp[1] >> 32;
temp[1] &= 0xFFFFFFFF;
}
for ( i=0; i<FNV128size/4; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV128input */
/* hash in a string (64 bit)
********************************************************************/
int FNV128stringin ( FNV128context * const ctx, const char *in )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 53]
INTERNET-DRAFT FNV
uint64_t temp[FNV128size/4];
uint64_t temp2[2];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV128state:
ctx->Computed = FNVcomputed+FNV128state;
case FNVcomputed+FNV128state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV128size/4; ++i )
temp[i] = ctx->Hash[i];
while ( (ch = (uint8_t)*in++) )
{
/* temp = FNV128prime * ( temp ^ ch ); */
temp2[1] = temp[3] << FNV128shift;
temp2[0] = temp[2] << FNV128shift;
temp[3] = FNV128primeX * ( temp[3] ^ *in++ );
temp[2] *= FNV128primeX;
temp[1] = temp[1] * FNV128primeX + temp2[1];
temp[0] = temp[0] * FNV128primeX + temp2[0];
temp[2] += temp[3] >> 32;
temp[3] &= 0xFFFFFFFF;
temp[1] += temp[2] >> 32;
temp[2] &= 0xFFFFFFFF;
temp[0] += temp[1] >> 32;
temp[1] &= 0xFFFFFFFF;
}
for ( i=0; i<FNV128size/4; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV128stringin */
/* return hash (64 bit)
********************************************************************/
int FNV128result ( FNV128context * const ctx, uint8_t out[FNV128size] )
{
int i;
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV128state )
G. Fowler, L. Noll, K. Vo, et. al [Page 54]
INTERNET-DRAFT FNV
return fnvStateError;
for ( i=0; i<FNV128size/4; ++i )
{
#ifdef FNV_BigEndian
out[15-4*i] = ctx->Hash[i];
out[14-4*i] = ctx->Hash[i] >> 8;
out[13-4*i] = ctx->Hash[i] >> 16;
out[12-4*i] = ctx->Hash[i] >> 24;
#else
out[4*i] = ctx->Hash[i];
out[4*i+1] = ctx->Hash[i] >> 8;
out[4*i+2] = ctx->Hash[i] >> 16;
out[4*i+3] = ctx->Hash[i] >> 24;
#endif
ctx -> Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV128state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV128result */
/******************************************************************
* END VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
******************************************************************/
#else /* FNV_64bitIntegers */
/******************************************************************
* START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
******************************************************************/
/* 128 bit FNV_prime = 2^88 + 2^8 + 0x3b */
/* 0x00000000 01000000 00000000 0000013B */
#define FNV128primeX 0x013B
#define FNV128shift 8
/* 0x6C62272E 07BB0142 62B82175 6295C58D */
uint16_t FNV128basis[FNV128size/2] =
{ 0x6C62, 0x272E, 0x07BB, 0x0142,
0x62B8, 0x2175, 0x6295, 0xC58D };
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV128 *
********************************************************************/
/* initialize context (32 bit)
********************************************************************/
int FNV128init ( FNV128context *ctx )
{
int i;
G. Fowler, L. Noll, K. Vo, et. al [Page 55]
INTERNET-DRAFT FNV
if ( ctx )
{
for ( i=0; i<FNV128size/2; ++i )
ctx->Hash[i] = FNV128basis[i];
ctx->Computed = FNVinited+FNV128state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV128init */
/* initialize context with a provided basis (32 bit)
********************************************************************/
int FNV128initBasis ( FNV128context *ctx,
const uint8_t basis[FNV128size] )
{
int i;
const uint8_t *ui8p;
uint32_t temp;
if ( ctx )
{
#ifdef FNV_BigEndian
ui8p = basis;
for ( i=0; i < FNV128size/2; ++i )
{
temp = *ui8p++;
ctx->Hash[i] = ( temp<<8 ) + (*ui8p++);
}
#else
ui8p = basis + (FNV128size/2 - 1);
for ( i=0; i < FNV128size/2; ++i )
{
temp = *ui8p--;
ctx->Hash[i] = ( temp<<8 ) + (*ui8p--);
}
#endif
ctx->Computed = FNVinited+FNV128state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV128initBasis */
/* hash in a counted block (32 bit)
*******************************************************************/
int FNV128blockin ( FNV128context *ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp[FNV128size/2];
G. Fowler, L. Noll, K. Vo, et. al [Page 56]
INTERNET-DRAFT FNV
uint32_t temp2[3];
int i;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV128state:
ctx->Computed = FNVcomputed+FNV128state;
case FNVcomputed+FNV128state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV128size/2; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV128prime * ( temp ^ *in++ ); */
temp[7] ^= *in++;
temp2[2] = temp[7] << FNV128shift;
temp2[1] = temp[6] << FNV128shift;
temp2[0] = temp[5] << FNV128shift;
for ( i=0; i<8; ++i )
temp[i] *= FNV128primeX;
temp[2] += temp2[2];
temp[1] += temp2[1];
temp[0] += temp2[0];
for ( i=7; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV128size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV128blockin */
/* hash in a string (32 bit)
*******************************************************************/
int FNV128stringin ( FNV128context *ctx,
const char *in )
{
uint32_t temp[FNV128size/2];
uint32_t temp2[3];
G. Fowler, L. Noll, K. Vo, et. al [Page 57]
INTERNET-DRAFT FNV
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV128state:
ctx->Computed = FNVcomputed+FNV128state;
case FNVcomputed+FNV128state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV128size/2; ++i )
temp[i] = ctx->Hash[i];
while ( (ch = (uint8_t)*in++) )
{
/* temp = FNV128prime * ( temp ^ *in++ ); */
temp[7] ^= ch;
temp2[2] = temp[7] << FNV128shift;
temp2[1] = temp[6] << FNV128shift;
temp2[0] = temp[5] << FNV128shift;
for ( i=0; i<8; ++i )
temp[i] *= FNV128primeX;
temp[2] += temp2[2];
temp[1] += temp2[1];
temp[0] += temp2[0];
for ( i=7; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV128size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV128stringin */
/* return hash (32 bit)
********************************************************************/
int FNV128result ( FNV128context *ctx,
uint8_t out[FNV128size] )
{
int i;
if ( ctx && out )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 58]
INTERNET-DRAFT FNV
if ( ctx->Computed != FNVcomputed+FNV128state )
return fnvStateError;
for ( i=0; i<FNV128size/2; ++i )
{
#ifdef FNV_BigEndian
out[15-2*i] = ctx->Hash[i];
out[14-2*i] = ctx->Hash[i] >> 8;
#else
out[2*i] = ctx->Hash[i];
out[2*i+1] = ctx->Hash[i] >> 8;
#endif
ctx -> Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV128state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV128result */
#endif /* Have64bitIntegers */
/********************************************************************
* END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
********************************************************************/
#endif /* _FNV128_C_ */
<CODE ENDS>
6.1.4 FNV256 C Code
The header and C source for 256-bit FNV-1a returning a byte vector.
<CODE BEGINS>
/**************************** FNV256.h **************************/
/***************** See RFC NNNN for details. ********************/
/*
* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV256_H_
#define _FNV256_H_
/*
* Description:
* This file provides headers for the 256-bit version of the
* FNV-1a non-cryptographic hash algorithm.
*/
G. Fowler, L. Noll, K. Vo, et. al [Page 59]
INTERNET-DRAFT FNV
#include "FNVconfig.h"
#include <stdint.h>
#define FNV256size (256/8)
/* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following types:
*
* type meaning
* uint64_t unsigned 64 bit integer (ifdef FNV_64bitIntegers)
* uint32_t unsigned 32 bit integer
* uint16_t unsigned 16 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
*/
#ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_
/*********************************************************************
* All FNV functions provided return as integer as follows:
* 0 -> success
* >0 -> error as listed below
*/
enum { /* success and errors */
fnvSuccess = 0,
fnvNull, /* Null pointer parameter */
fnvStateError, /* called Input after Result or before Init */
fnvBadParam /* passed a bad parameter */
};
#endif /* _FNV_ErrCodes_ */
/*
* This structure holds context information for an FNV256 hash
*/
#ifdef FNV_64bitIntegers
/* version if 64 bit integers supported */
typedef struct FNV256context_s {
int Computed; /* state */
uint32_t Hash[FNV256size/4];
} FNV256context;
#else
/* version if 64 bit integers NOT supported */
typedef struct FNV256context_s {
int Computed; /* state */
uint16_t Hash[FNV256size/2];
} FNV256context;
#endif /* FNV_64bitIntegers */
G. Fowler, L. Noll, K. Vo, et. al [Page 60]
INTERNET-DRAFT FNV
/*
* Function Prototypes
* FNV256string: hash a zero terminated string not including
* the zero
* FNV256block: FNV256 hash a specified length byte vector
* FNV256init: initializes an FNV256 context
* FNV256initBasis: initializes an FNV256 context with a provided
* basis
* FNV256blockin: hash in a specified length byte vector
* FNV256stringin: hash in a zero terminated string not
* including the zero
* FNV256result: returns the hash value
*
* Hash is returned as an array of 8-bit integers
*/
#ifdef __cplusplus
extern "C" {
#endif
/* FNV256 */
extern int FNV256string ( const char *in,
uint8_t out[FNV256size] );
extern int FNV256block ( const void *in,
long int length,
uint8_t out[FNV256size] );
extern int FNV256init ( FNV256context *);
extern int FNV256initBasis ( FNV256context * const,
const uint8_t basis[FNV256size] );
extern int FNV256blockin ( FNV256context * const,
const void *in,
long int length );
extern int FNV256stringin ( FNV256context * const,
const char *in );
extern int FNV256result ( FNV256context * const,
uint8_t out[FNV256size] );
#ifdef __cplusplus
}
#endif
#endif /* _FNV256_H_ */
<CODE ENDS>
<CODE BEGINS>
/***************************** FNV256.c ****************************/
/******************** See RFC NNNN for details *********************/
/* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights
* See fnv-private.h for terms of use and redistribution.
G. Fowler, L. Noll, K. Vo, et. al [Page 61]
INTERNET-DRAFT FNV
*/
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic
* hash function FNV-1a for 256-bit hashes.
*/
#ifndef _FNV256_C_
#define _FNV256_C_
#include "fnv-private.h"
#include "FNV256.h"
/* common code for 64 and 32 bit modes */
/* FNV256 hash a null terminated string (64/32 bit)
********************************************************************/
int FNV256string ( const char *in, uint8_t out[FNV256size] )
{
FNV256context ctx;
int err;
if ( (err = FNV256init ( &ctx )) != fnvSuccess )
return err;
if ( (err = FNV256stringin ( &ctx, in )) != fnvSuccess )
return err;
return FNV256result ( &ctx, out );
} /* end FNV256string */
/* FNV256 hash a counted block (64/32 bit)
********************************************************************/
int FNV256block ( const void *in,
long int length,
uint8_t out[FNV256size] )
{
FNV256context ctx;
int err;
if ( (err = FNV256init ( &ctx )) != fnvSuccess )
return err;
if ( (err = FNV256blockin ( &ctx, in, length)) != fnvSuccess )
return err;
return FNV256result ( &ctx, out );
} /* end FNV256block */
/********************************************************************
* START VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
********************************************************************/
#ifdef FNV_64bitIntegers
G. Fowler, L. Noll, K. Vo, et. al [Page 62]
INTERNET-DRAFT FNV
/* 256 bit FNV_prime = 2^168 + 2^8 + 0x63 */
/* 0x0000000000000000 0000010000000000
0000000000000000 0000000000000163 */
#define FNV256primeX 0x0163
#define FNV256shift 8
/* 0xDD268DBCAAC55036 2D98C384C4E576CC
C8B1536847B6BBB3 1023B4C8CAEE0535 */
uint32_t FNV256basis[FNV256size/4] = {
0xDD268DBC, 0xAAC55036, 0x2D98C384, 0xC4E576CC,
0xC8B15368, 0x47B6BBB3, 0x1023B4C8, 0xCAEE0535 };
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV256 *
********************************************************************/
/* initialize context (64 bit)
********************************************************************/
int FNV256init ( FNV256context *ctx )
{
int i;
if ( ctx )
{
for ( i=0; i<FNV256size/4; ++i )
ctx->Hash[i] = FNV256basis[i];
ctx->Computed = FNVinited+FNV256state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV256init */
/* initialize context with a provided basis (64 bit)
********************************************************************/
int FNV256initBasis ( FNV256context* const ctx,
const uint8_t basis[FNV256size] )
{
int i;
const uint8_t *ui8p;
uint32_t temp;
if ( ctx )
{
#ifdef FNV_BigEndian
ui8p = basis;
for ( i=0; i < FNV256size/4; ++i )
{
temp = (*ui8p++)<<8;
temp = (temp + *ui8p++)<<8;
G. Fowler, L. Noll, K. Vo, et. al [Page 63]
INTERNET-DRAFT FNV
temp = (temp + *ui8p++)<<8;
ctx->Hash[i] = temp + *ui8p;
}
#else
ui8p = basis + (FNV256size/4 - 1);
for ( i=0; i < FNV256size/4; ++i )
{
temp = (*ui8p--)<<8;
temp = (temp + *ui8p--)<<8;
temp = (temp + *ui8p--)<<8;
ctx->Hash[i] = temp + *ui8p;
}
#endif
ctx->Computed = FNVinited+FNV256state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV256initBasis */
/* hash in a counted block (64 bit)
********************************************************************/
int FNV256blockin ( FNV256context *ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint64_t temp[FNV256size/4];
uint64_t temp2[3];
int i;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV256state:
ctx->Computed = FNVcomputed+FNV256state;
case FNVcomputed+FNV256state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV256size/4; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV256prime * ( temp ^ *in++ ); */
temp[7] ^= *in++;
temp2[2] = temp[7] << FNV256shift;
G. Fowler, L. Noll, K. Vo, et. al [Page 64]
INTERNET-DRAFT FNV
temp2[1] = temp[6] << FNV256shift;
temp2[0] = temp[5] << FNV256shift;
for ( i=0; i<FNV256size/4; ++i )
temp[i] *= FNV256primeX;
temp[2] += temp2[2];
temp[1] += temp2[1];
temp[0] += temp2[0];
for ( i=FNV256size/4-1; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV256size/4; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV256input */
/* hash in a string (64 bit)
********************************************************************/
int FNV256stringin ( FNV256context *ctx, const char *in )
{
uint64_t temp[FNV256size/4];
uint64_t temp2[3];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV256state:
ctx->Computed = FNVcomputed+FNV256state;
case FNVcomputed+FNV256state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV256size/4; ++i )
temp[i] = ctx->Hash[i];
while ( (ch = (uint8_t)*in++) )
{
/* temp = FNV256prime * ( temp ^ ch ); */
temp[7] ^= ch;
temp2[2] = temp[7] << FNV256shift;
temp2[1] = temp[6] << FNV256shift;
temp2[0] = temp[5] << FNV256shift;
for ( i=0; i<FNV256size/4; ++i )
G. Fowler, L. Noll, K. Vo, et. al [Page 65]
INTERNET-DRAFT FNV
temp[i] *= FNV256primeX;
temp[2] += temp2[2];
temp[1] += temp2[1];
temp[0] += temp2[0];
for ( i=FNV256size/4-1; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV256size/4; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV256stringin */
/* return hash (64 bit)
********************************************************************/
int FNV256result ( FNV256context *ctx, uint8_t out[FNV256size] )
{
int i;
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV256state )
return fnvStateError;
for ( i=0; i<FNV256size/4; ++i )
{
#ifdef FNV_BigEndian
out[31-4*i] = ctx->Hash[i];
out[31-4*i] = ctx->Hash[i] >> 8;
out[31-4*i] = ctx->Hash[i] >> 16;
out[31-4*i] = ctx->Hash[i] >> 24;
#else
out[4*i] = ctx->Hash[i];
out[4*i+1] = ctx->Hash[i] >> 8;
out[4*i+2] = ctx->Hash[i] >> 16;
out[4*i+3] = ctx->Hash[i] >> 24;
#endif
ctx -> Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV256state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV256result */
/******************************************************************
* END VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
G. Fowler, L. Noll, K. Vo, et. al [Page 66]
INTERNET-DRAFT FNV
******************************************************************/
#else /* FNV_64bitIntegers */
/******************************************************************
* 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 */
/* 0x00000000 00000000 00000100 00000000
00000000 00000000 00000000 00000163 */
#define FNV256primeX 0x0163
#define FNV256shift 8
/* 0xDD268DBCAAC55036 2D98C384C4E576CC
C8B1536847B6BBB3 1023B4C8CAEE0535 */
uint16_t FNV256basis[FNV256size/2] = {
0xDD26, 0x8DBC, 0xAAC5, 0x5036,
0x2D98, 0xC384, 0xC4E5, 0x76CC,
0xC8B1, 0x5368, 0x47B6, 0xBBB3,
0x1023, 0xB4C8, 0xCAEE, 0x0535 };
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV256 *
********************************************************************/
/* initialize context (32 bit)
********************************************************************/
int FNV256init ( FNV256context *ctx )
{
int i;
if ( ctx )
{
for ( i=0; i<FNV256size/2; ++i )
ctx->Hash[i] = FNV256basis[i];
ctx->Computed = FNVinited+FNV256state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV256init */
/* initialize context with a provided basis (32 bit)
********************************************************************/
int FNV256initBasis ( FNV256context *ctx,
const uint8_t basis[FNV256size] )
{
int i;
G. Fowler, L. Noll, K. Vo, et. al [Page 67]
INTERNET-DRAFT FNV
const uint8_t *ui8p;
uint32_t temp;
if ( ctx )
{
#ifdef FNV_BigEndian
ui8p = basis;
for ( i=0; i < FNV256size/2; ++i )
{
temp = *ui8p++;
ctx->Hash[i] = ( temp<<8 ) + (*ui8p++);
}
#else
ui8p = basis + FNV256size/2 -1;
for ( i=0; i < FNV256size/2; ++i )
{
temp = *ui8p--;
ctx->Hash[i] = ( temp<<8 ) + (*ui8p--);
}
#endif
ctx->Computed = FNVinited+FNV256state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV256initBasis */
/* hash in a counted block (32 bit)
*******************************************************************/
int FNV256blockin ( FNV256context *ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp[FNV256size/2];
uint32_t temp2[6];
int i;
if ( ctx && in )
{
if ( length < 0 )
return fnvBadParam;
switch ( ctx->Computed )
{
case FNVinited+FNV256state:
ctx->Computed = FNVcomputed+FNV256state;
case FNVcomputed+FNV256state:
break;
default:
return fnvStateError;
}
G. Fowler, L. Noll, K. Vo, et. al [Page 68]
INTERNET-DRAFT FNV
for ( i=0; i<FNV256size/2; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV256prime * ( temp ^ *in++ ); */
temp[15] ^= *in++;
for ( i=0; i<6; ++i )
temp2[i] = temp[10+i] << FNV256shift;
for ( i=0; i<FNV256size/2; ++i )
temp[i] *= FNV256primeX;
for ( i=0; i<6; ++i )
temp[10+i] += temp2[i];
for ( i=15; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV256size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV256blockin */
/* hash in a string (32 bit)
*******************************************************************/
int FNV256stringin ( FNV256context *ctx, const char *in )
{
uint32_t temp[FNV256size/2];
uint32_t temp2[6];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV256state:
ctx->Computed = FNVcomputed+FNV256state;
case FNVcomputed+FNV256state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV256size/2; ++i )
temp[i] = ctx->Hash[i];
while ( ( ch = (uint8_t)*in++ ) != 0)
{
/* temp = FNV256prime * ( temp ^ *in++ ); */
G. Fowler, L. Noll, K. Vo, et. al [Page 69]
INTERNET-DRAFT FNV
temp[15] ^= ch;
for ( i=0; i<6; ++i )
temp2[i] = temp[10+i] << FNV256shift;
for ( i=0; i<FNV256size/2; ++i )
temp[i] *= FNV256primeX;
for ( i=0; i<6; ++i )
temp[10+i] += temp2[i];
for ( i=15; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV256size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV256stringin */
/* return hash (32 bit)
********************************************************************/
int FNV256result ( FNV256context *ctx, uint8_t out[FNV256size] )
{
int i;
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV256state )
return fnvStateError;
for ( i=0; i<FNV256size/2; ++i )
{
#ifdef FNV_BigEndian
out[31-2*i] = ctx->Hash[i];
out[30-2*i] = ctx->Hash[i] >> 8;
#else
out[2*i] = ctx->Hash[i];
out[2*i+1] = ctx->Hash[i] >> 8;
#endif
ctx->Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV256state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV256result */
#endif /* Have64bitIntegers */
/********************************************************************
* END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
G. Fowler, L. Noll, K. Vo, et. al [Page 70]
INTERNET-DRAFT FNV
********************************************************************/
#endif /* _FNV256_C_ */
<CODE ENDS>
6.1.5 FNV512 C Code
The header and C source for 512-bit FNV-1a returning a byte vector.
<CODE BEGINS>
/**************************** FNV512.h **************************/
/***************** See RFC NNNN for details. ********************/
/*
* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV512_H_
#define _FNV512_H_
/*
* Description:
* This file provides headers for the 512-bit version of the
* FNV-1a non-cryptographic hash algorithm.
*/
#include "FNVconfig.h"
#include <stdint.h>
#define FNV512size (512/8)
/* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following types:
*
* type meaning
* uint64_t unsigned 64 bit integer (ifdef FNV_64bitIntegers)
* uint32_t unsigned 32 bit integer
* uint16_t unsigned 16 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
*/
#ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_
/*********************************************************************
* All FNV functions provided return as integer as follows:
* 0 -> success
* >0 -> error as listed below
G. Fowler, L. Noll, K. Vo, et. al [Page 71]
INTERNET-DRAFT FNV
*/
enum { /* success and errors */
fnvSuccess = 0,
fnvNull, /* Null pointer parameter */
fnvStateError, /* called Input after Result or before Init */
fnvBadParam /* passed a bad parameter */
};
#endif /* _FNV_ErrCodes_ */
/*
* This structure holds context information for an FNV512 hash
*/
#ifdef FNV_64bitIntegers
/* version if 64 bit integers supported */
typedef struct FNV512context_s {
int Computed; /* state */
uint32_t Hash[FNV512size/4];
} FNV512context;
#else
/* version if 64 bit integers NOT supported */
typedef struct FNV512context_s {
int Computed; /* state */
uint16_t Hash[FNV512size/2];
} FNV512context;
#endif /* FNV_64bitIntegers */
/*
* Function Prototypes
* FNV512string: hash a zero terminated string not including
* the terminating zero
* FNV512block: FNV512 hash a specified length byte vector
* FNV512init: initializes an FNV512 context
* FNV512initBasis: initializes an FNV512 context with a
* provided basis
* FNV512blockin: hash in a specified length byte vector
* FNV512stringin: hash in a zero terminated string not
* including the zero
* FNV512result: returns the hash value
*
* Hash is returned as an array of 8-bit integers
*/
#ifdef __cplusplus
extern "C" {
#endif
/* FNV512 */
G. Fowler, L. Noll, K. Vo, et. al [Page 72]
INTERNET-DRAFT FNV
extern int FNV512string ( const char *in,
uint8_t out[FNV512size] );
extern int FNV512block ( const void *in,
long int length,
uint8_t out[FNV512size] );
extern int FNV512init ( FNV512context *);
extern int FNV512initBasis ( FNV512context * const,
const uint8_t basis[FNV512size] );
extern int FNV512blockin ( FNV512context *,
const void *in,
long int length );
extern int FNV512stringin ( FNV512context *,
const char *in );
extern int FNV512result ( FNV512context *,
uint8_t out[FNV512size] );
#ifdef __cplusplus
}
#endif
#endif /* _FNV512_H_ */
<CODE ENDS>
<CODE BEGINS>
/***************************** FNV512.c ****************************/
/******************** See RFC NNNN for details *********************/
/* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights
* See fnv-private.h for terms of use and redistribution.
*/
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic
* hash function FNV-1a for 512-bit hashes.
*/
#ifndef _FNV512_C_
#define _FNV512_C_
#include "fnv-private.h"
#include "FNV512.h"
/* common code for 64 and 32 bit modes */
/* FNV512 hash a null terminated string (64/32 bit)
********************************************************************/
int FNV512string ( const char *in, uint8_t out[FNV512size] )
{
FNV512context ctx;
int err;
G. Fowler, L. Noll, K. Vo, et. al [Page 73]
INTERNET-DRAFT FNV
if ( (err = FNV512init ( &ctx )) != fnvSuccess )
return err;
if ( (err = FNV512stringin ( &ctx, in )) != fnvSuccess )
return err;
return FNV512result ( &ctx, out );
} /* end FNV512string */
/* FNV512 hash a counted block (64/32 bit)
********************************************************************/
int FNV512block ( const void *in,
long int length,
uint8_t out[FNV512size] )
{
FNV512context ctx;
int err;
if ( (err = FNV512init ( &ctx )) != fnvSuccess )
return err;
if ( (err = FNV512blockin ( &ctx, in, length)) != fnvSuccess )
return err;
return FNV512result ( &ctx, out );
} /* end FNV512block */
/********************************************************************
* START VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
********************************************************************/
#ifdef FNV_64bitIntegers
/*
512 bit FNV_prime = 2^344 + 2^8 + 0x57 =
0x0000000000000000 0000000000000000
0000000001000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000157 */
#define FNV512primeX 0x0157
#define FNV512shift 24
/* 0xB86DB0B1171F4416 DCA1E50F309990AC
AC87D059C9000000 0000000000000D21
E948F68A34C192F6 2EA79BC942DBE7CE
182036415F56E34B AC982AAC4AFE9FD9 */
uint32_t FNV512basis[FNV512size/4] = {
0xB86DB0B1, 0x171F4416, 0xDCA1E50F, 0x209990AC,
0xAC87D059, 0x9C000000, 0x00000000, 0x00000D21,
0xE948F68A, 0x34C192F6, 0x2EA79BC9, 0x42DBE7CE,
0x18203641, 0x5F56E34B, 0xAC982AAC, 0x4AFE9FD9 };
/********************************************************************
G. Fowler, L. Noll, K. Vo, et. al [Page 74]
INTERNET-DRAFT FNV
* Set of init, input, and output functions below *
* to incrementally compute FNV512 *
********************************************************************/
/* initialize context (64 bit)
********************************************************************/
int FNV512init ( FNV512context *ctx )
{
if ( ctx )
{
for ( i=0; i<FNV512size/4; ++i )
ctx->Hash[i] = FNV512basis[i];
ctx->Computed = FNVinited+FNV512state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV512init */
/* initialize context with a provided basis (64 bit)
********************************************************************/
int FNV512initBasis ( FNV512context* const ctx,
const uint8_t basis[FNV512size] )
{
int i;
const uint8_t *ui8p;
uint32_t temp;
if ( ctx )
{
#ifdef FNV_BigEndian
ui8p = basis;
for ( i=0; i < FNV512size/4; ++i )
{
temp = (*ui8p++)<<8;
temp = (temp + *ui8p++)<<8;
temp = (temp + *ui8p++)<<8;
ctx->Hash[i] = temp + *ui8p;
}
#else
ui8p = basis + (FNV512size/4 - 1);
for ( i=0; i < FNV512size/4; ++i )
{
temp = (*ui8p--)<<8;
temp = (temp + *ui8p--)<<8;
temp = (temp + *ui8p--)<<8;
ctx->Hash[i] = temp + *ui8p;
}
#endif
ctx->Computed = FNVinited+FNV512state;
return fnvSuccess;
G. Fowler, L. Noll, K. Vo, et. al [Page 75]
INTERNET-DRAFT FNV
}
return fnvNull;
} /* end FNV512initBasis */
/* hash in a counted block (64 bit)
********************************************************************/
int FNV512blockin ( FNV512context *ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint64_t temp[FNV512size/4];
uint64_t temp2[3];
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV512state:
ctx->Computed = FNVcomputed+FNV128state;
case FNVcomputed+FNV512state:
break;
default:
return fnvStateError;
}
if ( length < 0 )
return fnvBadParam;
for ( i=0; i<FNV512size/4; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV512prime * ( temp ^ *in++ ); */
temp[7] ^= *in++;
temp2[2] = temp[7] << FNV512shift;
temp2[1] = temp[6] << FNV512shift;
temp2[0] = temp[5] << FNV512shift;
for ( i=0; i<FNV512size/4; ++i )
temp[i] *= FNV512primeX;
temp[2] += temp2[2];
temp[1] += temp2[1];
temp[0] += temp2[0];
for ( i=FNV512size/4-1; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV512size/4; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
G. Fowler, L. Noll, K. Vo, et. al [Page 76]
INTERNET-DRAFT FNV
}
return fnvNull;
} /* end FNV512input */
/* hash in a string (64 bit)
********************************************************************/
inf FNV512stringin ( FNV512context *ctx, const char *in )
{
uint64_t temp[FNV512size/4];
uint64_t temp2[2];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV512state:
ctx->Computed = FNVcomputed+FNV512state;
case FNVcomputed+FNV512state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV512size/4; ++i )
temp[i] = ctx->Hash[i];
while ( ch = (uint8_t)*in++ )
{
/* temp = FNV512prime * ( temp ^ ch ); */
temp[7] ^= ch;
temp2[2] = temp[7] << FNV128shift;
temp2[1] = temp[6] << FNV128shift;
temp2[0] = temp[5] << FNV128shift;
for ( i=0; i<FNV512size/4; ++i )
temp[i] *= FNV512prime;
temp[2] += temp2[2];
temp[1] += temp2[1];
temp[0] += temp2[0];
for ( i=FNVsize512/4-1; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV512size/4; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV512stringin */
G. Fowler, L. Noll, K. Vo, et. al [Page 77]
INTERNET-DRAFT FNV
/* return hash (64 bit)
********************************************************************/
int FNV512result ( FNV512context *ctx, uint8_t out[FNV512size] )
{
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV512state )
return fnvStateError;
for ( i=0; i<FNV512size/4; ++i )
{
#ifdef FNV_BigEndian
out[15-2*i] = ctx->Hash[i];
out[14-2*i] = ctx->Hash[i] >> 8;
#else
out[2*i] = ctx->Hash[i];
out[2*i+1] = ctx->Hash[i] >> 8;
#endif
ctx -> Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV512state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV512result */
/******************************************************************
* END VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
******************************************************************/
#else /* FNV_64bitIntegers */
/******************************************************************
* START VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
******************************************************************/
/* version for when you only have 32-bit arithmetic
********************************************************************/
/*
512 bit FNV_prime = 2^344 + 2^8 + 0x57 =
0x0000000000000000 0000000000000000
0000000001000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000157 */
#define FNV512primeX 0x0157
#define FNV512shift 8
/* 0xB86DB0B1171F4416 DCA1E50F309990AC
AC87D059C9000000 0000000000000D21
E948F68A34C192F6 2EA79BC942DBE7CE
182036415F56E34B AC982AAC4AFE9FD9 */
G. Fowler, L. Noll, K. Vo, et. al [Page 78]
INTERNET-DRAFT FNV
uint16_t FNV512basis[FNV512size/2] = {
0xB86D, 0xB0B1, 0x171F, 0x4416, 0xDCA1, 0xE50F, 0x3099, 0x90AC,
0xAC87, 0xD059, 0xC900, 0x0000, 0x0000, 0x0000, 0x0000, 0x0D21,
0xE948, 0xF68A, 0x34C1, 0x92F6, 0x2EA7, 0x9BC9, 0x42DB, 0xE7CE,
0x1820, 0x3641, 0x5F56, 0xE34B, 0xAC98, 0x2AAC, 0x4AFE, 0x9FD9 };
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV512 *
********************************************************************/
/* initialize context (32 bit)
********************************************************************/
int FNV512init ( FNV512context *ctx )
{
int i;
if ( ctx )
{
for ( i=0; i<FNV512size/2; ++i )
ctx->Hash[i] = FNV512basis[i];
ctx->Computed = FNVinited+FNV512state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV512init */
/* initialize context with a provided basis (32 bit)
********************************************************************/
int FNV512initBasis ( FNV512context *ctx,
const uint8_t basis[FNV512size] )
{
int i;
const uint8_t *ui8p;
uint32_t temp;
if ( ctx )
{
#ifdef FNV_BigEndian
ui8p = basis;
for ( i=0; i < FNV512size/2; ++i )
{
temp = *ui8p++;
ctx->Hash[i] = ( temp<<8 ) + (*ui8p++);
}
#else
ui8p = basis + ( FNV512size/2 - 1 );
for ( i=0; i < FNV512size/2; ++i )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 79]
INTERNET-DRAFT FNV
temp = *ui8p--;
ctx->Hash[i] = ( temp<<8 ) + (*ui8p--);
}
#endif
ctx->Computed = FNVinited+FNV512state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV512initBasis */
/* hash in a counted block (32 bit)
*******************************************************************/
int FNV512blockin ( FNV512context *ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp[FNV512size/2];
uint32_t temp2[6];
int i;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV512state:
ctx->Computed = FNVcomputed+FNV512state;
case FNVcomputed+FNV512state:
break;
default:
return fnvStateError;
}
if ( length < 0 )
return fnvBadParam;
for ( i=0; i<FNV512size/2; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV512prime * ( temp ^ *in++ ); */
temp[15] ^= *in++;
for ( i=0; i<6; ++i )
temp2[i] = temp[10+i] << FNV512shift;
for ( i=0; i<FNV512size/2; ++i )
temp[i] *= FNV512primeX;
for ( i=0; i<6; ++i )
temp[10+i] += temp2[i];
for ( i=15; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
G. Fowler, L. Noll, K. Vo, et. al [Page 80]
INTERNET-DRAFT FNV
}
}
for ( i=0; i<FNV512size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV512blockin */
/* hash in a string (32 bit)
*******************************************************************/
int FNV512stringin ( FNV512context *ctx, const char *in )
{
uint32_t temp[FNV512size/2];
uint32_t temp2[6];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV512state:
ctx->Computed = FNVcomputed+FNV512state;
case FNVcomputed+FNV512state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV512size/2; ++i )
temp[i] = ctx->Hash[i];
while ( (ch = (uint8_t)*in++) )
{
/* temp = FNV512prime * ( temp ^ *in++ ); */
temp[15] ^= ch;
for ( i=0; i<6; ++i )
temp2[i] = temp[10+i] << FNV512shift;
for ( i=0; i<FNV512size/2; ++i )
temp[i] *= FNV512primeX;
for ( i=0; i<6; ++i )
temp[10+i] += temp2[i];
for ( i=15; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV512size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
G. Fowler, L. Noll, K. Vo, et. al [Page 81]
INTERNET-DRAFT FNV
}
return fnvNull;
} /* end FNV512stringin */
/* return hash (32 bit)
********************************************************************/
int FNV512result ( FNV512context *ctx, unsigned char out[16] )
{
int i;
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV512state )
return fnvStateError;
for ( i=0; i<FNV512size/2; ++i )
{
#ifdef FNV_BigEndian
out[31-2*i] = ctx->Hash[i];
out[30-2*i] = ctx->Hash[i] >> 8;
#else
out[2*i] = ctx->Hash[i];
out[2*i+1] = ctx->Hash[i] >> 8;
#endif
ctx->Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV512state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV512result */
#endif /* FNV_64bitIntegers */
/********************************************************************
* END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
********************************************************************/
#endif /* _FNV512_C_ */
<CODE ENDS>
6.1.6 FNV1024 C Code
The header and C source for 1024-bit FNV-1a returning a byte vector.
<CODE BEGINS>
/*************************** FNV1024.h **************************/
/***************** See RFC NNNN for details. ********************/
/*
* Copyright (c) 2016 IETF Trust and the persons identified as
G. Fowler, L. Noll, K. Vo, et. al [Page 82]
INTERNET-DRAFT FNV
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
#ifndef _FNV1024_H_
#define _FNV1024_H_
/*
* Description:
* This file provides headers for the 1024-bit version of the
* FNV-1a non-cryptographic hash algorithm.
*/
#include "FNVconfig.h"
#include <stdint.h>
#define FNV1024size (1024/8)
/* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following types:
*
* type meaning
* uint64_t unsigned 64 bit integer (ifdef FNV_64bitIntegers)
* uint32_t unsigned 32 bit integer
* uint16_t unsigned 16 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
*/
#ifndef _FNV_ErrCodes_
#define _FNV_ErrCodes_
/*********************************************************************
* All FNV functions provided return as integer as follows:
* 0 -> success
* >0 -> error as listed below
*/
enum { /* success and errors */
fnvSuccess = 0,
fnvNull, /* Null pointer parameter */
fnvStateError, /* called Input after Result or before Init */
fnvBadParam /* passed a bad parameter */
};
#endif /* _FNV_ErrCodes_ */
/*
* This structure holds context information for an FNV1024 hash
*/
#ifdef FNV_64bitIntegers
/* version if 64 bit integers supported */
typedef struct FNV1024context_s {
int Computed; /* state */
G. Fowler, L. Noll, K. Vo, et. al [Page 83]
INTERNET-DRAFT FNV
uint32_t Hash[FNV1024size/4];
} FNV1024context;
#else
/* version if 64 bit integers NOT supported */
typedef struct FNV1024context_s {
int Computed; /* state */
uint16_t Hash[FNV1024size/2];
} FNV1024context;
#endif /* FNV_64bitIntegers */
/*
* Function Prototypes
* FNV1024string: hash a zero terminated string not including
* the terminating zero
* FNV1024block: FNV1024 hash a specified length byte vector
* FNV1024init: initializes an FNV1024 context
* FNV1024initBasis: initializes an FNV1024 context with a
* provided basis
* FNV1024blockin: hash in a specified length byte vector
* FNV1024stringin: hash in a zero terminated string not
* including the zero
* FNV1024result: returns the hash value
*
* Hash is returned as an array of 8-bit integers
*/
#ifdef __cplusplus
extern "C" {
#endif
/* FNV1024 */
extern int FNV1024string ( const char *in,
unsigned char out[FNV1024size] );
extern int FNV1024block ( const void *in,
long int length,
unsigned char out[FNV1024size] );
extern int FNV1024init ( FNV1024context *);
extern int FNV1024initBasis ( FNV1024context * const,
const uint8_t basis[FNV1024size] );
extern int FNV1024blockin ( FNV1024context *,
const void *in,
long int length );
extern int FNV1024stringin ( FNV1024context *,
const char *in );
extern int FNV1024result ( FNV1024context *,
unsigned char out[FNV1024size] );
G. Fowler, L. Noll, K. Vo, et. al [Page 84]
INTERNET-DRAFT FNV
#ifdef __cplusplus
}
#endif
#endif /* _FNV1024_H_ */
<CODE ENDS>
<CODE BEGINS>
/***************************** FNV1024.c ****************************/
/******************** See RFC NNNN for details *********************/
/* Copyright (c) 2016, 2017 IETF Trust and the persons identified as
* authors of the code. All rights
* See fnv-private.h for terms of use and redistribution.
*/
/* This file implements the FNV (Fowler, Noll, Vo) non-cryptographic
* hash function FNV-1a for 1024-bit hashes.
*/
#ifndef _FNV1024_C_
#define _FNV1024_C_
#include "fnv-private.h"
#include "FNV1024.h"
/* common code for 64 and 32 bit modes */
/* FNV1024 hash a null terminated string (64/32 bit)
********************************************************************/
int FNV1024string ( const char *in, uint8_t out[FNV1024size] )
{
FNV1024context ctx;
int err;
if ( (err = FNV1024init ( &ctx )) != fnvSuccess)
return err;
if ( (err = FNV1024stringin ( &ctx, in )) != fnvSuccess)
return err;
return FNV1024result ( &ctx, out );
} /* end FNV1024string */
/* FNV1024 hash a counted block (64/32 bit)
********************************************************************/
int FNV1024block ( const void *in,
long int length,
uint8_t out[FNV1024size] )
{
FNV1024context ctx;
int err;
G. Fowler, L. Noll, K. Vo, et. al [Page 85]
INTERNET-DRAFT FNV
if ( (err = FNV1024init ( &ctx )) != fnvSuccess)
return err;
if ( (err = FNV1024blockin ( &ctx, in, length)) != fnvSuccess)
return err;
return FNV1024result ( &ctx, out );
} /* end FNV1024block */
/********************************************************************
* START VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
********************************************************************/
#ifdef FNV_64bitIntegers
/*
1024 bit FNV_prime = 2^680 + 2^8 + 0x8d =
0x0000000000000000 0000010000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 000000000000018D
#define FNV1024primeX 0x018D
#define FNV1024shift 24
/* 0x0000000000000000 005F7A76758ECC4D
32E56D5A591028B7 4B29FC4223FDADA1
6C3BF34EDA3674DA 9A21D90000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 000000000004C6D7
EB6E73802734510A 555F256CC005AE55
6BDE8CC9C6A93B21 AFF4B16C71EE90B3 */
uint32_t FNV1024basis[FNV1024size/4] = {
0x00000000, 0x00000000, 0x005F7A76, 0x758ECC4D,
0x32E56D5A, 0x591028B7, 0x4B29FC42, 0x23FDADA1,
0x6C3BF34E, 0xDA3674DA, 0x9A21D900, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x0004C6D7,
0xEB6E7380, 0x2734510A, 0x555F256C, 0xC005AE55,
0x6BDE8CC9, 0xC6A93B21, 0xAFF4B16C, 0x71EE90B3
};
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV1024 *
********************************************************************/
/* initialize context (64 bit)
G. Fowler, L. Noll, K. Vo, et. al [Page 86]
INTERNET-DRAFT FNV
********************************************************************/
int FNV1024init ( FNV1024context *ctx )
{
if ( ctx )
{
for ( i=0; i<FNV1024size/4; ++i )
ctx->Hash[i] = FNV1024basis[i];
ctx->Computed = FNVinited+FNV1024state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024init */
/* initialize context with a provided basis (64 bit)
********************************************************************/
int FNV1024initBasis ( FNV1024context* const ctx,
const uint8_t basis[FNV1024size] )
{
int i;
uint8_t *ui8p;
uint32_t temp;
if ( ctx )
{
#ifdef FNV_BigEndian
ui8p = basis;
for ( i=0; i < FNV1024size/4; ++i )
{
temp = (*ui8p++)<<8;
temp = (temp + *ui8p++)<<8;
temp = (temp + *ui8p++)<<8;
ctx->Hash[i] = temp + *ui8p;
}
#else
ui8p = basis + (FNV1024size/4 - 1);
for ( i=0; i < FNV1024size/4; ++i )
{
temp = (*ui8p--)<<8;
temp = (temp + *ui8p--)<<8;
temp = (temp + *ui8p--)<<8;
ctx->Hash[i] = temp + *ui8p;
}
#endif
ctx->Computed = FNVinited+FNV1024state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024initBasis */
/* hash in a counted block (64 bit)
G. Fowler, L. Noll, K. Vo, et. al [Page 87]
INTERNET-DRAFT FNV
********************************************************************/
int FNV1024blockin ( FNV1024context *ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint64_t temp[FNV1024size/4];
uint64_t temp2[3];
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV1024state:
ctx->Computed = FNVcomputed+FNV128state;
case FNVcomputed+FNV1024state:
break;
default:
return fnvStateError;
}
if ( length < 0 )
return fnvBadParam;
for ( i=0; i<FNV1024size/4; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV1024prime * ( temp ^ *in++ ); */
temp[7] ^= *in++;
temp2[2] = temp[7] << FNV1024shift;
temp2[1] = temp[6] << FNV1024shift;
temp2[0] = temp[5] << FNV1024shift;
for ( i=0; i<FNV1024size/4; ++i )
temp[i] *= FNV1024primeX;
temp[2] += temp2[2];
temp[1] += temp2[1];
temp[0] += temp2[0];
for ( i=FNV1024size/4-1; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV1024size/4; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024input */
/* hash in a string (64 bit)
G. Fowler, L. Noll, K. Vo, et. al [Page 88]
INTERNET-DRAFT FNV
********************************************************************/
inf FNV1024stringin ( FNV1024context *ctx, const char *in )
{
uint64_t temp[FNV1024size/4];
uint64_t temp2[2];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV1024state:
ctx->Computed = FNVcomputed+FNV1024state;
case FNVcomputed+FNV1024state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV1024size/4; ++i )
temp[i] = ctx->Hash[i];
while ( ch = (uint8_t)*in++ )
{
/* temp = FNV1024prime * ( temp ^ ch ); */
temp[7] ^= ch;
temp2[2] = temp[7] << FNV128shift;
temp2[1] = temp[6] << FNV128shift;
temp2[0] = temp[5] << FNV128shift;
for ( i=0; i<FNV1024size/4; ++i )
temp[i] *= FNV1024prime;
temp[2] += temp2[2];
temp[1] += temp2[1];
temp[0] += temp2[0];
for ( i=FNVsize1024/4-1; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV1024size/4; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024stringin */
/* return hash (64 bit)
********************************************************************/
int FNV1024result ( FNV1024context *ctx, uint8_t out[FNV1024size] )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 89]
INTERNET-DRAFT FNV
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV1024state )
return fnvStateError;
for ( i=0; i<FNV1024size/4; ++i )
{
#ifdef FNV_BigEndian
out[15-2*i] = ctx->Hash[i];
out[14-2*i] = ctx->Hash[i] >> 8;
#else
out[2*i] = ctx->Hash[i];
out[2*i+1] = ctx->Hash[i] >> 8;
#endif
ctx -> Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV1024state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024result */
/******************************************************************
* END VERSION FOR WHEN YOU HAVE 64 BIT ARITHMETIC *
******************************************************************/
#else /* FNV_64bitIntegers */
/******************************************************************
* 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 =
0x0000000000000000 0000010000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 000000000000018D */
#define FNV1024primeX 0x018D
#define FNV1024shift 8
/* 0x0000000000000000 005F7A76758ECC4D
32E56D5A591028B7 4B29FC4223FDADA1
6C3BF34EDA3674DA 9A21D90000000000
0000000000000000 0000000000000000
0000000000000000 0000000000000000
0000000000000000 000000000004C6D7
EB6E73802734510A 555F256CC005AE55
G. Fowler, L. Noll, K. Vo, et. al [Page 90]
INTERNET-DRAFT FNV
6BDE8CC9C6A93B21 AFF4B16C71EE90B3 */
uint16_t FNV1024basis[FNV1024size/2] = {
0x0000, 0x0000, 0x0000, 0x0000, 0x005F, 0x7A76, 0x758E, 0xCC4D,
0x32E5, 0x6D5A, 0x5910, 0x28B7, 0x4B29, 0xFC42, 0x23FD, 0xADA1,
0x6C3B, 0xF34E, 0xDA36, 0x74DA, 0x9A21, 0xD900, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0004, 0xC6D7,
0xEB6E, 0x7380, 0x2734, 0x510A, 0x555F, 0x256C, 0xC005, 0xAE55,
0x6BDE, 0x8CC9, 0xC6A9, 0x3B21, 0xAFF4, 0xB16C, 0x71EE, 0x90B3
};
/********************************************************************
* Set of init, input, and output functions below *
* to incrementally compute FNV1024 *
********************************************************************/
/* initialize context (32 bit)
********************************************************************/
int FNV1024init ( FNV1024context *ctx )
{
int i;
if ( ctx )
{
for ( i=0; i<FNV1024size/2; ++i )
ctx->Hash[i] = FNV1024basis[i];
ctx->Computed = FNVinited+FNV1024state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024init */
/* initialize context with a provided basis (32 bit)
********************************************************************/
int FNV1024initBasis ( FNV1024context *ctx,
const uint8_t basis[FNV1024size] )
{
int i;
const uint8_t *ui8p;
uint32_t temp;
if ( ctx )
{
#ifdef FNV_BigEndian
ui8p = basis;
for ( i=0; i < FNV1024size/2; ++i )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 91]
INTERNET-DRAFT FNV
temp = *ui8p++;
ctx->Hash[i] = ( temp<<8 ) + (*ui8p++);
}
#else
ui8p = basis + ( FNV1024size/2 - 1 );
for ( i=0; i < FNV1024size/2; ++i )
{
temp = *ui8p--;
ctx->Hash[i] = ( temp<<8 ) + (*ui8p--);
}
#endif
ctx->Computed = FNVinited+FNV1024state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024initBasis */
/* hash in a counted block (32 bit)
*******************************************************************/
int FNV1024blockin ( FNV1024context *ctx,
const void *vin,
long int length )
{
const uint8_t *in = (const uint8_t*)vin;
uint32_t temp[FNV1024size/2];
uint32_t temp2[6];
int i;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV1024state:
ctx->Computed = FNVcomputed+FNV1024state;
case FNVcomputed+FNV1024state:
break;
default:
return fnvStateError;
}
if ( length < 0 )
return fnvBadParam;
for ( i=0; i<FNV1024size/2; ++i )
temp[i] = ctx->Hash[i];
for ( ; length > 0; length-- )
{
/* temp = FNV1024prime * ( temp ^ *in++ ); */
temp[15] ^= *in++;
for ( i=0; i<6; ++i )
temp2[i] = temp[10+i] << FNV1024shift;
for ( i=0; i<FNV1024size/2; ++i )
G. Fowler, L. Noll, K. Vo, et. al [Page 92]
INTERNET-DRAFT FNV
temp[i] *= FNV1024primeX;
for ( i=0; i<6; ++i )
temp[10+i] += temp2[i];
for ( i=15; i>0; --i )
{
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV1024size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024blockin */
/* hash in a string (32 bit)
*******************************************************************/
int FNV1024stringin ( FNV1024context *ctx, const char *in )
{
uint32_t temp[FNV1024size/2];
uint32_t temp2[6];
int i;
uint8_t ch;
if ( ctx && in )
{
switch ( ctx->Computed )
{
case FNVinited+FNV1024state:
ctx->Computed = FNVcomputed+FNV1024state;
case FNVcomputed+FNV1024state:
break;
default:
return fnvStateError;
}
for ( i=0; i<FNV1024size/2; ++i )
temp[i] = ctx->Hash[i];
while ( (ch = (uint8_t)*in++) )
{
/* temp = FNV1024prime * ( temp ^ *in++ ); */
temp[15] ^= ch;
for ( i=0; i<6; ++i )
temp2[i] = temp[10+i] << FNV1024shift;
for ( i=0; i<FNV1024size/2; ++i )
temp[i] *= FNV1024primeX;
for ( i=0; i<6; ++i )
temp[10+i] += temp2[i];
for ( i=15; i>0; --i )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 93]
INTERNET-DRAFT FNV
temp[i-1] += temp[i] >> 16;
temp[i] &= 0xFFFF;
}
}
for ( i=0; i<FNV1024size/2; ++i )
ctx->Hash[i] = temp[i];
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024stringin */
/* return hash (32 bit)
********************************************************************/
int FNV1024result ( FNV1024context *ctx, unsigned char out[16] )
{
int i;
if ( ctx && out )
{
if ( ctx->Computed != FNVcomputed+FNV1024state )
return fnvStateError;
for ( i=0; i<FNV1024size/2; ++i )
{
#ifdef FNV_BigEndian
out[31-2*i] = ctx->Hash[i];
out[30-2*i] = ctx->Hash[i] >> 8;
#else
out[2*i] = ctx->Hash[i];
out[2*i+1] = ctx->Hash[i] >> 8;
#endif
ctx->Hash[i] = 0;
}
ctx->Computed = FNVemptied+FNV1024state;
return fnvSuccess;
}
return fnvNull;
} /* end FNV1024result */
#endif /* FNV_64bitIntegers */
/********************************************************************
* END VERSION FOR WHEN YOU ONLY HAVE 32-BIT ARITHMETIC *
********************************************************************/
#endif /* _FNV1024_C_ */
<CODE ENDS>
G. Fowler, L. Noll, K. Vo, et. al [Page 94]
INTERNET-DRAFT FNV
6.2 FNV Test Code
Here is a test driver:
<CODE BEGINS>
/**************************** MAIN.c ****************************/
/****************** See RFC NNNN for details. *******************/
/*
* Copyright (c) 2016 IETF Trust and the persons identified as
* authors of the code. All rights reserved.
* See fnv-private.h for terms of use and redistribution.
*/
/* to do a thorough test you need to run will all four
combinations of the following defined/undefined */
// #define FNV_64bitIntegers
// #define FNV_BigEndian
#include <stdio.h>
#include <string.h>
#include "fnv-private.h"
#include "FNV.h"
/* global variables */
char *funcName;
char *errteststring = "foo";
int Terr; /* Total errors */
#define NTestBytes 3
uint8_t errtestbytes[NTestBytes] = { (uint8_t)1,
(uint8_t)2, (uint8_t)3 };
#define NTstrings 3
char *teststring[NTstrings] = { "", "a", "foobar" };
/*****************************************************************
* local prototypes
*****************************************************************/
int TestR ( char *, int should, int was );
void TestNValue ( char *subfunc,
char *string,
int N,
uint8_t *should,
uint8_t *was );
void HexPrint ( int i, unsigned char *p );
void Test32 ();
void Test32Value ( char *subfunc, char *string,
uint32_t was, uint32_t should );
void Test64 ();
#ifdef FNV_64bitIntegers
G. Fowler, L. Noll, K. Vo, et. al [Page 95]
INTERNET-DRAFT FNV
void Test64Value ( char *subfunc, char *string,
uint64_t should, uint64_t was );
#else
#define uint64_t foobar
#endif /* FNB_64bitIntegers */
void Test128 ();
void Test256 ();
void Test512 ();
void Test1024 ();
void TestNValue ( char *subfunc,
char *string,
int N,
uint8_t was[N],
uint8_t should[N] );
/*****************************************************************
* main
*****************************************************************/
int main (int argc, const char * argv[])
{
#ifdef FNV_64bitIntegers
printf ("Have 64-bit Integers. ");
#else
printf ("Do not have 64-bit integers. ");
#endif
#ifdef FNV_BigEndian
printf ("Calculating for Big Endian.0);
#else
printf ("Not calculating for Big Endian.0);
#endif
funcName = "Testing TestR ";
/* test the Test Return function */
TestR ( "should fail", 1, 2 );
TestR ( "should not have failed", 0, 0 );
Test32();
Test64();
Test128();
Test256();
Test512();
Test1024();
printf ("Type return to exit.0);
(void)getchar();
printf ("Goodbye!0);
return 0;
} /* end main */
G. Fowler, L. Noll, K. Vo, et. al [Page 96]
INTERNET-DRAFT FNV
/* Test status returns
*****************************************************************/
int TestR ( char *name, int expect, int actual )
{
if ( expect != actual )
{
printf ( "%s%s returned %i instead of %i.0,
funcName, name, actual, expect );
++Terr;
}
return actual;
} /* end TestR */
/* Return true if the bytes are in reverse order from each other */
int revcmp(uint8_t *buf1, uint8_t *buf2, int N) {
int i;
uint8_t *bufc = buf2 + N;
for ( i = 0; i < N / 2; i++ )
if (*buf1++ != *--bufc)
return 0;
return 1;
}
/* General byte vector return error test
*****************************************************************/
void TestNValue ( char *subfunc,
char *string,
int N,
uint8_t *was,
uint8_t *should )
{
#ifdef FNV_BigEndian
if ( revcmp ( was, should, N) == 0)
#else
if ( memcmp ( was, should, N) != 0)
#endif
{
printf ( "%s %s of '%s' computed ", funcName, subfunc, string );
HexPrint ( N, was );
printf ( ", should have been " );
HexPrint ( N, should );
printf ( ".0 );
++Terr;
}
} /* end TestNValue */
/* print some hex
*****************************************************************/
void HexPrint ( int count, unsigned char *ptr )
{
G. Fowler, L. Noll, K. Vo, et. al [Page 97]
INTERNET-DRAFT FNV
int i;
for ( i = 0; i < count; ++i )
printf ( "%02X", ptr[i] );
} /* end HexPrint */
/*****************************************************************
* FNV32 test
*****************************************************************/
void Test32 ()
{
int i, err;
long int iLen;
uint32_t eUint32;
FNV32context eContext;
uint32_t FNV32svalues[NTstrings] = {
0x811c9dc5, 0xe40c292c, 0xbf9cf968 };
uint32_t FNV32bvalues[NTstrings] = {
0x050c5d1f, 0x2b24d044, 0x0c1c9eb8 };
/* test Test32Value */
funcName = "Test32Value";
Test32Value ( "should fail", "test", FNV32svalues[1], FNV32svalues[2] );
funcName = "FNV32";
/* test error checks */
Terr = 0;
TestR ( "init", fnvSuccess, FNV32init (&eContext) );
TestR ( "string", fnvNull,
FNV32string ( (char *)0, &eUint32 ) );
TestR ( "string", fnvNull,
FNV32string ( errteststring, (uint32_t *)0 ) );
TestR ( "block", fnvNull,
FNV32block ( (uint8_t *)0, 1, &eUint32 ) );
TestR ( "block", fnvBadParam,
FNV32block ( errtestbytes, -1, &eUint32 ) );
TestR ( "block", fnvNull,
FNV32block ( errtestbytes, 1, (uint32_t *)0 ) );
TestR ( "init", fnvNull,
FNV32init ( (FNV32context *)0 ) );
TestR ( "initBasis", fnvNull,
FNV32initBasis ( (FNV32context *)0, 42 ) );
TestR ( "blockin", fnvNull,
FNV32blockin ( (FNV32context *)0,
errtestbytes, NTestBytes ) );
TestR ( "blockin", fnvNull,
FNV32blockin ( &eContext, (uint8_t *)0,
NTestBytes ) );
G. Fowler, L. Noll, K. Vo, et. al [Page 98]
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TestR ( "blockin", fnvBadParam,
FNV32blockin ( &eContext, errtestbytes, -1 ) );
eContext.Computed = FNVclobber+FNV32state;
TestR ( "blockin", fnvStateError,
FNV32blockin ( &eContext, errtestbytes,
NTestBytes ) );
TestR ( "stringin", fnvNull,
FNV32stringin ( (FNV32context *)0, errteststring ) );
TestR ( "stringin", fnvNull,
FNV32stringin ( &eContext, (char *)0 ) );
TestR ( "stringin", fnvStateError,
FNV32stringin ( &eContext, errteststring ) );
TestR ( "result", fnvNull,
FNV32result ( (FNV32context *)0, &eUint32 ) );
TestR ( "result", fnvNull,
FNV32result ( &eContext, (uint32_t *)0 ) );
TestR ( "result", fnvStateError,
FNV32result ( &eContext, &eUint32 ) );
if ( Terr )
printf ( "%s test of error checks failed %i times.0,
funcName, Terr );
else
printf ( "%s test of error checks passed0, funcName );
/* test actual results */
Terr = 0;
for ( i = 0; i < NTstrings; ++i )
{
err = TestR ( "string", fnvSuccess,
FNV32string ( teststring[i], &eUint32 ) );
if ( err == fnvSuccess )
Test32Value ( "string", teststring[i], eUint32,
FNV32svalues[i] );
err = TestR ( "block", fnvSuccess,
FNV32block ( (uint8_t *)teststring[i],
(unsigned long)(strlen(teststring[i])+1),
&eUint32 ) );
if ( err == fnvSuccess )
Test32Value ( "block", teststring[i], eUint32,
FNV32bvalues[i] );
/* now try testing the incremental stuff */
err = TestR ( "init", fnvSuccess, FNV32init ( &eContext ) );
if ( err ) break;
iLen = strlen ( teststring[i] );
err = TestR ( "blockin", fnvSuccess,
FNV32blockin ( &eContext,
(uint8_t *)teststring[i],
iLen/2 ) );
if ( err ) break;
err = TestR ( "stringin", fnvSuccess,
G. Fowler, L. Noll, K. Vo, et. al [Page 99]
INTERNET-DRAFT FNV
FNV32stringin ( &eContext,
teststring[i] + iLen/2 ) );
err = TestR ( "result", fnvSuccess,
FNV32result ( &eContext, &eUint32 ) );
if ( err ) break;
Test32Value ( " incremental", teststring[i], eUint32,
FNV32svalues[i] );
}
if ( Terr )
printf ( "%s test of return values failed %i times.0,
funcName, Terr );
else
printf ( "%s test of return values passed.0, funcName );
} /* end Test32 */
/* start Test32Value
*****************************************************************/
void Test32Value ( char *subfunc,
char *string,
uint32_t was,
uint32_t should )
{
TestNValue(subfunc, string, sizeof(uint32_t), (uint8_t*)&was,
(uint8_t*)&should);
} /* end Test32Value */
#ifdef FNV_64bitIntegers
/*****************************************************************
* Code for FNV64 using 64-bit integers
*****************************************************************/
void Test64 ()
{
int i, err;
uint64_t eUint64 = 42;
FNV64context eContext;
uint64_t FNV64svalues[NTstrings] = {
0xcbf29ce484222325, 0xaf63dc4c8601ec8c, 0x85944171f73967e8 };
uint64_t FNV64bvalues[NTstrings] = {
0xaf63bd4c8601b7df, 0x089be207b544f1e4, 0x34531ca7168b8f38 };
funcName = "FNV64";
/* test error checks */
Terr = 0;
TestR ( "init", fnvSuccess, FNV64init (&eContext) );
TestR ( "string", fnvNull,
FNV64string ( (char *)0, &eUint64 ) );
TestR ( "string", fnvNull,
G. Fowler, L. Noll, K. Vo, et. al [Page 100]
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FNV64string ( errteststring, (uint64_t *)0 ) );
TestR ( "block", fnvNull,
FNV64block ( (uint8_t *)0, 1, &eUint64 ) );
TestR ( "block", fnvBadParam,
FNV64block ( errtestbytes, -1, &eUint64 ) );
TestR ( "block", fnvNull,
FNV64block ( errtestbytes, 1, (uint64_t *)0 ) );
TestR ( "init", fnvNull,
FNV64init ( (FNV64context *)0 ) );
TestR ( "initBasis", fnvNull,
FNV64initBasis ( (FNV64context *)0, 42 ) );
TestR ( "blockin", fnvNull,
FNV64blockin ( (FNV64context *)0,
errtestbytes, NTestBytes ) );
TestR ( "blockin", fnvNull,
FNV64blockin ( &eContext, (uint8_t *)0,
NTestBytes ) );
TestR ( "blockin", fnvBadParam,
FNV64blockin ( &eContext, errtestbytes, -1 ) );
eContext.Computed = FNVclobber+FNV64state;
TestR ( "blockin", fnvStateError,
FNV64blockin ( &eContext, errtestbytes,
NTestBytes ) );
TestR ( "stringin", fnvNull,
FNV64stringin ( (FNV64context *)0, errteststring ) );
TestR ( "stringin", fnvNull,
FNV64stringin ( &eContext, (char *)0 ) );
TestR ( "stringin", fnvStateError,
FNV64stringin ( &eContext, errteststring ) );
TestR ( "result", fnvNull,
FNV64result ( (FNV64context *)0, &eUint64 ) );
TestR ( "result", fnvNull,
FNV64result ( &eContext, (uint64_t *)0 ) );
TestR ( "result", fnvStateError,
FNV64result ( &eContext, &eUint64 ) );
if ( Terr )
printf ( "%s test of error checks failed %i times.0,
funcName, Terr );
else
printf ( "%s test of error checks passed0, funcName );
/* test actual results */
Terr = 0;
for ( i = 0; i < NTstrings; ++i )
{
err = TestR ( "string", fnvSuccess,
FNV64string ( teststring[i], &eUint64 ) );
if ( err == fnvSuccess )
Test64Value ( "string", teststring[i], eUint64,
FNV64svalues[i] );
G. Fowler, L. Noll, K. Vo, et. al [Page 101]
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err = TestR ( "block", fnvSuccess,
FNV64block ( (uint8_t *)teststring[i],
(unsigned long)(strlen(teststring[i])+1),
&eUint64 ) );
if ( err == fnvSuccess )
Test64Value ( "block", teststring[i], eUint64,
FNV64bvalues[i] );
/* now try testing the incremental stuff */
err = TestR ( "init", fnvSuccess, FNV64init ( &eContext ) );
}
if ( Terr )
printf ( "%s test of return values failed %i times.0,
funcName, Terr );
else
printf ( "%s test of return values passed.0, funcName );
} /* end Test64 */
/* start Test64Value
*****************************************************************/
void Test64Value ( char *subfunc,
char *string,
uint64_t should,
uint64_t was )
{
TestNValue(subfunc, string, sizeof(uint64_t), (uint8_t*)&was,
. (uint8_t*)&should);
} /* end Test64Value */
#else
void Test64 ()
{
/* TBD */
}
#endif /* FNV_64bitIntegers */
/*****************************************************************
* Code for FNV128 using 64-bit integers
*****************************************************************/
void Test128 ()
{
//int i, err;
uint8_t eUint128[FNV128size];
FNV128context eContext;
funcName = "FNV128";
/* test error checks */
Terr = 0;
G. Fowler, L. Noll, K. Vo, et. al [Page 102]
INTERNET-DRAFT FNV
TestR ( "init", fnvSuccess, FNV128init (&eContext) );
TestR ( "string", fnvNull,
FNV128string ( (char *)0, eUint128 ) );
TestR ( "string", fnvNull,
FNV128string ( errteststring, (uint8_t *)0 ) );
TestR ( "block", fnvNull,
FNV128block ( (uint8_t *)0, 1, eUint128 ) );
TestR ( "block", fnvBadParam,
FNV128block ( errtestbytes, -1, eUint128 ) );
TestR ( "block", fnvNull,
FNV128block ( errtestbytes, 1, (uint8_t *)0 ) );
TestR ( "init", fnvNull,
FNV128init ( (FNV128context *)0 ) );
TestR ( "initBasis", fnvNull,
FNV128initBasis ( (FNV128context *)0, eUint128 ) );
TestR ( "blockin", fnvNull,
FNV128blockin ( (FNV128context *)0,
errtestbytes, NTestBytes ) );
TestR ( "blockin", fnvNull,
FNV128blockin ( &eContext, (uint8_t *)0,
NTestBytes ) );
TestR ( "blockin", fnvBadParam,
FNV128blockin ( &eContext, errtestbytes, -1 ) );
eContext.Computed = FNVclobber+FNV128state;
TestR ( "blockin", fnvStateError,
FNV128blockin ( &eContext, errtestbytes,
NTestBytes ) );
TestR ( "stringin", fnvNull,
FNV128stringin ( (FNV128context *)0, errteststring ) );
TestR ( "stringin", fnvNull,
FNV128stringin ( &eContext, (char *)0 ) );
TestR ( "stringin", fnvStateError,
FNV128stringin ( &eContext, errteststring ) );
TestR ( "result", fnvNull,
FNV128result ( (FNV128context *)0, eUint128 ) );
TestR ( "result", fnvNull,
FNV128result ( &eContext, (uint8_t *)0 ) );
TestR ( "result", fnvStateError,
FNV128result ( &eContext, eUint128 ) );
if ( Terr )
printf ( "%s test of error checks failed %i times.0,
funcName, Terr );
else
printf ( "%s test of error checks passed0, funcName );
/* test actual results */
Terr = 0;
/* tbd */
} /* end Test128 */
G. Fowler, L. Noll, K. Vo, et. al [Page 103]
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/*****************************************************************
* Code for FNV256 using 64-bit integers
*****************************************************************/
void Test256 ()
{
//int i, err;
uint8_t eUint256[FNV256size];
FNV256context eContext;
funcName = "FNV256";
/* test error checks */
Terr = 0;
TestR ( "init", fnvSuccess, FNV256init (&eContext) );
TestR ( "string", fnvNull,
FNV256string ( (char *)0, eUint256 ) );
TestR ( "string", fnvNull,
FNV256string ( errteststring, (uint8_t *)0 ) );
TestR ( "block", fnvNull,
FNV256block ( (uint8_t *)0, 1, eUint256 ) );
TestR ( "block", fnvBadParam,
FNV256block ( errtestbytes, -1, eUint256 ) );
TestR ( "block", fnvNull,
FNV256block ( errtestbytes, 1, (uint8_t *)0 ) );
TestR ( "init", fnvNull,
FNV256init ( (FNV256context *)0 ) );
TestR ( "initBasis", fnvNull,
FNV256initBasis ( (FNV256context *)0, eUint256 ) );
TestR ( "blockin", fnvNull,
FNV256blockin ( (FNV256context *)0,
errtestbytes, NTestBytes ) );
TestR ( "blockin", fnvNull,
FNV256blockin ( &eContext, (uint8_t *)0,
NTestBytes ) );
TestR ( "blockin", fnvBadParam,
FNV256blockin ( &eContext, errtestbytes, -1 ) );
eContext.Computed = FNVclobber+FNV256state;
TestR ( "blockin", fnvStateError,
FNV256blockin ( &eContext, errtestbytes,
NTestBytes ) );
TestR ( "stringin", fnvNull,
FNV256stringin ( (FNV256context *)0, errteststring ) );
TestR ( "stringin", fnvNull,
FNV256stringin ( &eContext, (char *)0 ) );
TestR ( "stringin", fnvStateError,
FNV256stringin ( &eContext, errteststring ) );
TestR ( "result", fnvNull,
FNV256result ( (FNV256context *)0, eUint256 ) );
TestR ( "result", fnvNull,
G. Fowler, L. Noll, K. Vo, et. al [Page 104]
INTERNET-DRAFT FNV
FNV256result ( &eContext, (uint8_t *)0 ) );
TestR ( "result", fnvStateError,
FNV256result ( &eContext, eUint256 ) );
if ( Terr )
printf ( "%s test of error checks failed %i times.0,
funcName, Terr );
else
printf ( "%s test of error checks passed0, funcName );
/* test actual results */
Terr = 0;
/* tbd */
} /* end Test256 */
/*****************************************************************
* Code for FNV512 using 64-bit integers
*****************************************************************/
void Test512 ()
{
//int i, err;
uint8_t eUint512[FNV512size];
FNV512context eContext;
funcName = "FNV512";
/* test error checks */
Terr = 0;
TestR ( "init", fnvSuccess, FNV512init (&eContext) );
TestR ( "string", fnvNull,
FNV512string ( (char *)0, eUint512 ) );
TestR ( "string", fnvNull,
FNV512string ( errteststring, (uint8_t *)0 ) );
TestR ( "block", fnvNull,
FNV512block ( (uint8_t *)0, 1, eUint512 ) );
TestR ( "block", fnvBadParam,
FNV512block ( errtestbytes, -1, eUint512 ) );
TestR ( "block", fnvNull,
FNV512block ( errtestbytes, 1, (uint8_t *)0 ) );
TestR ( "init", fnvNull,
FNV512init ( (FNV512context *)0 ) );
TestR ( "initBasis", fnvNull,
FNV512initBasis ( (FNV512context *)0, eUint512 ) );
TestR ( "blockin", fnvNull,
FNV512blockin ( (FNV512context *)0,
errtestbytes, NTestBytes ) );
TestR ( "blockin", fnvNull,
FNV512blockin ( &eContext, (uint8_t *)0,
NTestBytes ) );
G. Fowler, L. Noll, K. Vo, et. al [Page 105]
INTERNET-DRAFT FNV
TestR ( "blockin", fnvBadParam,
FNV512blockin ( &eContext, errtestbytes, -1 ) );
eContext.Computed = FNVclobber+FNV512state;
TestR ( "blockin", fnvStateError,
FNV512blockin ( &eContext, errtestbytes,
NTestBytes ) );
TestR ( "stringin", fnvNull,
FNV512stringin ( (FNV512context *)0, errteststring ) );
TestR ( "stringin", fnvNull,
FNV512stringin ( &eContext, (char *)0 ) );
TestR ( "stringin", fnvStateError,
FNV512stringin ( &eContext, errteststring ) );
TestR ( "result", fnvNull,
FNV512result ( (FNV512context *)0, eUint512 ) );
TestR ( "result", fnvNull,
FNV512result ( &eContext, (uint8_t *)0 ) );
TestR ( "result", fnvStateError,
FNV512result ( &eContext, eUint512 ) );
if ( Terr )
printf ( "%s test of error checks failed %i times.0,
funcName, Terr );
else
printf ( "%s test of error checks passed0, funcName );
/* test actual results */
Terr = 0;
/* tbd */
} /* end Test512 */
/*****************************************************************
* Code for FNV1024 using 64-bit integers
*****************************************************************/
void Test1024 ()
{
//int i, err;
uint8_t eUint1024[FNV1024size];
FNV1024context eContext;
funcName = "FNV1024";
/* test error checks */
Terr = 0;
TestR ( "init", fnvSuccess, FNV1024init (&eContext) );
TestR ( "string", fnvNull,
FNV1024string ( (char *)0, eUint1024 ) );
TestR ( "string", fnvNull,
FNV1024string ( errteststring, (uint8_t *)0 ) );
TestR ( "block", fnvNull,
G. Fowler, L. Noll, K. Vo, et. al [Page 106]
INTERNET-DRAFT FNV
FNV1024block ( (uint8_t *)0, 1, eUint1024 ) );
TestR ( "block", fnvBadParam,
FNV1024block ( errtestbytes, -1, eUint1024 ) );
TestR ( "block", fnvNull,
FNV1024block ( errtestbytes, 1, (uint8_t *)0 ) );
TestR ( "init", fnvNull,
FNV1024init ( (FNV1024context *)0 ) );
TestR ( "initBasis", fnvNull,
FNV1024initBasis ( (FNV1024context *)0, eUint1024 ) );
TestR ( "blockin", fnvNull,
FNV1024blockin ( (FNV1024context *)0,
errtestbytes, NTestBytes ) );
TestR ( "blockin", fnvNull,
FNV1024blockin ( &eContext, (uint8_t *)0,
NTestBytes ) );
TestR ( "blockin", fnvBadParam,
FNV1024blockin ( &eContext, errtestbytes, -1 ) );
eContext.Computed = FNVclobber+FNV1024state;
TestR ( "blockin", fnvStateError,
FNV1024blockin ( &eContext, errtestbytes,
NTestBytes ) );
TestR ( "stringin", fnvNull,
FNV1024stringin ( (FNV1024context *)0, errteststring ) );
TestR ( "stringin", fnvNull,
FNV1024stringin ( &eContext, (char *)0 ) );
TestR ( "stringin", fnvStateError,
FNV1024stringin ( &eContext, errteststring ) );
TestR ( "result", fnvNull,
FNV1024result ( (FNV1024context *)0, eUint1024 ) );
TestR ( "result", fnvNull,
FNV1024result ( &eContext, (uint8_t *)0 ) );
TestR ( "result", fnvStateError,
FNV1024result ( &eContext, eUint1024 ) );
if ( Terr )
printf ( "%s test of error checks failed %i times.0,
funcName, Terr );
else
printf ( "%s test of error checks passed0, funcName );
/* test actual results */
Terr = 0;
/* tbd */
} /* end Test1024 */
<CODE ENDS>
G. Fowler, L. Noll, K. Vo, et. al [Page 107]
INTERNET-DRAFT FNV
7. Security Considerations
This document is intended to provide convenient open source access by
the Internet community to the FNV non-cryptographic hash. No
assertion of suitability for cryptographic applications is made for
the FNV hash algorithms.
7.1 Why is FNV Non-Cryptographic?
A full discussion of cryptographic hash requirements and strength is
beyond the scope of this document. However, here are three
characteristics of FNV that would generally be considered to make it
non-cryptographic:
1. Sticky State - A cryptographic hash should not have a state in
which it can stick for a plausible input pattern. But, in the very
unlikely event that the FNV hash variable becomes zero and the
input is a sequence of zeros, the hash variable will 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 input
bytes. Of course, for the common case of fixed length input, this
would usually not be significant because the number of non-zero
bytes would vary inversely with the number of zero bytes and for
some types of input, runs of zeros do not occur. Furthermore, the
inclusion of even a little unpredictable input may be sufficient
to stop an adversary from inducing a zero hash variable.
2. Diffusion - Every output bit of a cryptographic hash should be 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 of
the least significant bits of every input byte and does not depend
on any other input bit. While more complex, the second 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 order bits, depend on all input bits. If these properties
are considered a problem, they can be easily fixed by XOR folding
(see Section 3).
3. Work Factor - Depending on intended use, it is frequently
desirable that a hash function should be computationally expensive
for general purpose and graphics processors since these may be
profusely available through elastic cloud services or botnets.
This is to slow down testing of possible inputs if the output is
known. But FNV is designed to be very inexpensive on a general-
purpose processor. (See Appendix A.)
Nevertheless, none of the above have proven to be a problem in actual
practice for the many applications of FNV.
G. Fowler, L. Noll, K. Vo, et. al [Page 108]
INTERNET-DRAFT FNV
7.2 Inducing Collisions
While use of a cryptographic hash should be considered when active
adversaries are a factor, the following attack can be made much more
difficult with very minor changes in the use of FNV.
If FNV is being used in a known way for hash tables in a network
server or the like, for example some part of a web server, an
adversary could send requests calculated to cause hash table
collisions and induce substantial processing delays. As mentioned in
Section 2.2, use of an offset_basis not knownable by the adversary
will substantially eliminate this problem.
G. Fowler, L. Noll, K. Vo, et. al [Page 109]
INTERNET-DRAFT FNV
8. IANA Considerations
This document requires no IANA Actions. RFC Ediotor: Please delete
this section before publication.
Normative References
[RFC20] - Cerf, V., "ASCII format for network interchange", STD 80,
RFC 20, October 1969, <http://www.rfc-editor.org/info/rfc20>.
Informative References
[FNV] - FNV web site:
http://www.isthe.com/chongo/tech/comp/fnv/index.html
[IEEE] - http://www.ieee.org
[IPv6flow] - https://researchspace.auckland.ac.nz/bitstream/handle/
2292/13240/flowhashRep.pdf
[RFC2460] - Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998,
<http://www.rfc-editor.org/info/rfc2460>.
[RFC3174] - Eastlake 3rd, D. and P. Jones, "US Secure Hash Algorithm
1 (SHA1)", RFC 3174, September 2001.
[RFC6194] - Polk, T., Chen, L., Turner, S., and P. Hoffman, "Security
Considerations for the SHA-0 and SHA-1 Message-Digest
Algorithms", RFC 6194, March 2011.
[RFC6234] - Eastlake 3rd, D. and T. Hansen, "US Secure Hash
Algorithms (SHA and SHA-based HMAC and HKDF)", RFC 6234, May
2011.
[RFC6437] - Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme,
"IPv6 Flow Label Specification", RFC 6437, November 2011,
<http://www.rfc-editor.org/info/rfc6437>.
G. Fowler, L. Noll, K. Vo, et. al [Page 110]
INTERNET-DRAFT FNV
Acknowledgements
The contributions of the following are gratefully acknowledged:
Roman Donchenko, Frank Ellermann, Tony Finch, Bob Moskowitz,
Gayle Noble, Stefan Santesson, and Mukund Sivaraman.
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Appendix A: Work Comparison with SHA-1
This section provides a simplistic rough comparison of the level of
effort required per input byte to compute FNV-1a and SHA-1 [RFC3174].
Ignoring transfer of control and conditional tests and equating all
logical and arithmetic operations, FNV requires 2 operations per
byte, an XOR and a multiply.
SHA-1 is a relatively weak cryptographic hash producing a 160-bit
hash. It has been partially broken [RFC6194]. It is actually designed
to accept a bit vector input although almost all computer uses apply
it to an integer number of bytes. It processes blocks of 512 bits (64
bytes) and we estimate the effort involved in SHA-1 processing a full
block. Ignoring SHA-1 initial set up, transfer of control, and
conditional tests, but counting all logical and arithmetic
operations, including counting indexing as an addition, SHA-1
requires 1,744 operations per 64 bytes block or 27.25 operations per
byte. So by this rough measure, it is a little over 13 times the
effort of FNV for large amounts of data. However, FNV is commonly
used for small inputs. Using the above method, for inputs of N bytes,
where N is <= 55 so SHA-1 will take one block (SHA-1 includes padding
and an 8-byte length at the end of the data in the last block), the
ratio of the effort for SHA-1 to the effort for FNV will be 872/N.
For example, with an 8 byte input, SHA-1 will take 109 times as much
effort as FNV.
Stronger cryptographic functions than SHA-1 generally have an even
higher work factor.
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Appendix B: Previous IETF Reference to FNV
FNV-1a was referenced in draft-ietf-tls-cached-info-08.txt that has
since expired. It was later decided that it would be better to use a
cryptographic hash for that application.
Below is the Java code for FNV64 from that TLS draft included by the
kind permission of the author:
<CODE BEGINS>
/**
* Java code sample, implementing 64 bit FNV-1a
* By Stefan Santesson
*/
import java.math.BigInteger;
public class FNV {
static public BigInteger getFNV1aToByte(byte[] inp) {
BigInteger m = new BigInteger("2").pow(64);
BigInteger fnvPrime = new BigInteger("1099511628211");
BigInteger fnvOffsetBasis =
new BigInteger("14695981039346656037");
BigInteger digest = fnvOffsetBasis;
for (byte b : inp) {
digest = digest.xor(BigInteger.valueOf((int) b & 255));
digest = digest.multiply(fnvPrime).mod(m);
}
return digest;
}
}
<CODE ENDS>
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Appendix C: A Few Test Vectors
Below are a few test vectors in the form of ASCII strings and their
FNV32 and FNV64 hashes using the FNV-1a algorithm.
Strings without null (zero byte) termination:
String FNV32 FNV64
"" 0x811c9dc5 0xcbf29ce484222325
"a" 0xe40c292c 0xaf63dc4c8601ec8c
"foobar" 0xbf9cf968 0x85944171f73967e8
Strings including null (zero byte) termination:
String FNV32 FNV64
"" 0x050c5d1f 0xaf63bd4c8601b7df
"a" 0x2b24d044 0x089be207b544f1e4
"foobar" 0x0c1c9eb8 0x34531ca7168b8f38
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Appendix Z: Change Summary
RFC Editor Note: Please delete this appendix on publication.
From -00 to -01
1. Add Security Considerations section on why FNV is non-
cryptographic.
2. Add Appendix A on a work factor comparison with SHA-1.
3. Add Appendix B concerning previous IETF draft referenced to FNV.
4. Minor editorial changes.
From -01 to -02
1. Correct FNV_Prime determination criteria and add note as to why s
< 5 and s > 10 are not considered.
2. Add acknowledgements list.
3. Add a couple of references.
4. Minor editorial changes.
From -02 to -03
1. Replace direct reference to US-ASCII standard with reference to
RFC 20.
2. Update dates and version number.
3. Minor editing changes.
From -03 to -04
1. Change reference to RFC 20 back to a reference to the ANSI 1968
ASCII standard.
2. Minor addition to Section 6, point 3.
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3. Update dates and version number.
4. Minor editing changes.
From -04 to -05
1. Add Twitter as a use example and IPv6 flow hash study reference.
2. Update dates and version number.
From -05 to -06
1. Add code subsections.
2. Update dates and version number.
From -06 to -07 to -08
1. Update Author info.
2. Minor edits.
From -08 to -09
1. Change reference for ASCII to [RFC20].
2. Add more details on history of the string used to compute
offset_basis.
3. Re-write "Work Factor" part of Section 6 to be more precise.
4. Minor editorial changes.
From -09 to -10
1. Inclusion of initial partial version of code and some
documentation about the code, Section 6.
2. Insertion of new Section 4 on hashing values.
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From -10 to -11
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.
From -11 to -12
Keep alive update.
From -12 to -13
Fixed bug in pseudocode in Section 2.3.
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
Endianness consistency is not required.
From -13 to -14 to -15 to -16 to -17
Keep alive updates. Update an author address.
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Author's Address
Glenn Fowler
Google
Email: glenn.s.fowler@gmail.com
Landon Curt Noll
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134 USA
Telephone: +1-408-424-1102
Email: http://www.isthe.com/chongo/address.html
URL: http://www.isthe.com/chongo/index.html
Kiem-Phong Vo
Google
Email: phongvo@gmail.com
Donald Eastlake
Huawei Technologies
1424 Pro Shop Court
Davenport, FL 33896 USA
Telephone: +1-508-333-2270
EMail: d3e3e3@gmail.com
Tony Hansen
AT&T Laboratories
200 Laurel Ave. South
Middletown, NJ 07748
USA
Email: tony@att.com
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Copyright, Disclaimer, and Additional IPR Provisions
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This document is subject to BCP 78 and the IETF Trust's Legal
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. This Internet-Draft is
submitted in full conformance with the provisions of BCP 78 and BCP
79.
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