openssl/crypto/siphash/siphash.c
Todd Short 3f5616d734 Add support for parameterized SipHash
The core SipHash supports either 8 or 16-byte output and a configurable
number of rounds.
The default behavior, as added to EVP, is to use 16-byte output and
2,4 rounds, which matches the behavior of most implementations.
There is an EVP_PKEY_CTRL that can control the output size.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2216)
2017-02-01 14:14:36 -05:00

230 lines
7.1 KiB
C

/*
* Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/* Based on https://131002.net/siphash C reference implementation */
/*
SipHash reference C implementation
Copyright (c) 2012-2016 Jean-Philippe Aumasson
<jeanphilippe.aumasson@gmail.com>
Copyright (c) 2012-2014 Daniel J. Bernstein <djb@cr.yp.to>
To the extent possible under law, the author(s) have dedicated all copyright
and related and neighboring rights to this software to the public domain
worldwide. This software is distributed without any warranty.
You should have received a copy of the CC0 Public Domain Dedication along
with
this software. If not, see
<http://creativecommons.org/publicdomain/zero/1.0/>.
*/
#include <stdlib.h>
#include <string.h>
#include <openssl/crypto.h>
#include "internal/siphash.h"
#include "siphash_local.h"
/* default: SipHash-2-4 */
#define SIPHASH_C_ROUNDS 2
#define SIPHASH_D_ROUNDS 4
#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
#define U32TO8_LE(p, v) \
(p)[0] = (uint8_t)((v)); \
(p)[1] = (uint8_t)((v) >> 8); \
(p)[2] = (uint8_t)((v) >> 16); \
(p)[3] = (uint8_t)((v) >> 24);
#define U64TO8_LE(p, v) \
U32TO8_LE((p), (uint32_t)((v))); \
U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
#define U8TO64_LE(p) \
(((uint64_t)((p)[0])) | ((uint64_t)((p)[1]) << 8) | \
((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) | \
((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) | \
((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56))
#define SIPROUND \
do { \
v0 += v1; \
v1 = ROTL(v1, 13); \
v1 ^= v0; \
v0 = ROTL(v0, 32); \
v2 += v3; \
v3 = ROTL(v3, 16); \
v3 ^= v2; \
v0 += v3; \
v3 = ROTL(v3, 21); \
v3 ^= v0; \
v2 += v1; \
v1 = ROTL(v1, 17); \
v1 ^= v2; \
v2 = ROTL(v2, 32); \
} while (0)
size_t SipHash_ctx_size(void)
{
return sizeof(SIPHASH);
}
size_t SipHash_hash_size(SIPHASH *ctx)
{
return ctx->hash_size;
}
/* hash_size = crounds = drounds = 0 means SipHash24 with 16-byte output */
int SipHash_Init(SIPHASH *ctx, const unsigned char *k, int hash_size, int crounds, int drounds)
{
uint64_t k0 = U8TO64_LE(k);
uint64_t k1 = U8TO64_LE(k + 8);
if (hash_size == 0)
hash_size = SIPHASH_MAX_DIGEST_SIZE;
else if (hash_size != SIPHASH_MIN_DIGEST_SIZE &&
hash_size != SIPHASH_MAX_DIGEST_SIZE)
return 0;
if (drounds == 0)
drounds = SIPHASH_D_ROUNDS;
if (crounds == 0)
crounds = SIPHASH_C_ROUNDS;
ctx->crounds = crounds;
ctx->drounds = drounds;
ctx->hash_size = hash_size;
ctx->len = 0;
ctx->total_inlen = 0;
ctx->v0 = 0x736f6d6570736575ULL ^ k0;
ctx->v1 = 0x646f72616e646f6dULL ^ k1;
ctx->v2 = 0x6c7967656e657261ULL ^ k0;
ctx->v3 = 0x7465646279746573ULL ^ k1;
if (ctx->hash_size == SIPHASH_MAX_DIGEST_SIZE)
ctx->v1 ^= 0xee;
return 1;
}
void SipHash_Update(SIPHASH *ctx, const unsigned char *in, size_t inlen)
{
uint64_t m;
const uint8_t *end;
int left;
int i;
uint64_t v0 = ctx->v0;
uint64_t v1 = ctx->v1;
uint64_t v2 = ctx->v2;
uint64_t v3 = ctx->v3;
ctx->total_inlen += inlen;
if (ctx->len) {
/* deal with leavings */
size_t available = SIPHASH_BLOCK_SIZE - ctx->len;
/* not enough to fill leavings */
if (inlen < available) {
memcpy(&ctx->leavings[ctx->len], in, inlen);
ctx->len += inlen;
return;
}
/* copy data into leavings and reduce input */
memcpy(&ctx->leavings[ctx->len], in, available);
inlen -= available;
in += available;
/* process leavings */
m = U8TO64_LE(ctx->leavings);
v3 ^= m;
for (i = 0; i < ctx->crounds; ++i)
SIPROUND;
v0 ^= m;
}
left = inlen & (SIPHASH_BLOCK_SIZE-1); /* gets put into leavings */
end = in + inlen - left;
for (; in != end; in += 8) {
m = U8TO64_LE(in);
v3 ^= m;
for (i = 0; i < ctx->crounds; ++i)
SIPROUND;
v0 ^= m;
}
/* save leavings and other ctx */
if (left)
memcpy(ctx->leavings, end, left);
ctx->len = left;
ctx->v0 = v0;
ctx->v1 = v1;
ctx->v2 = v2;
ctx->v3 = v3;
}
int SipHash_Final(SIPHASH *ctx, unsigned char *out, size_t outlen)
{
/* finalize hash */
int i;
uint64_t b = ctx->total_inlen << 56;
uint64_t v0 = ctx->v0;
uint64_t v1 = ctx->v1;
uint64_t v2 = ctx->v2;
uint64_t v3 = ctx->v3;
if (outlen != (size_t)ctx->hash_size)
return 0;
switch (ctx->len) {
case 7:
b |= ((uint64_t)ctx->leavings[6]) << 48;
case 6:
b |= ((uint64_t)ctx->leavings[5]) << 40;
case 5:
b |= ((uint64_t)ctx->leavings[4]) << 32;
case 4:
b |= ((uint64_t)ctx->leavings[3]) << 24;
case 3:
b |= ((uint64_t)ctx->leavings[2]) << 16;
case 2:
b |= ((uint64_t)ctx->leavings[1]) << 8;
case 1:
b |= ((uint64_t)ctx->leavings[0]);
case 0:
break;
}
v3 ^= b;
for (i = 0; i < ctx->crounds; ++i)
SIPROUND;
v0 ^= b;
if (ctx->hash_size == SIPHASH_MAX_DIGEST_SIZE)
v2 ^= 0xee;
else
v2 ^= 0xff;
for (i = 0; i < ctx->drounds; ++i)
SIPROUND;
b = v0 ^ v1 ^ v2 ^ v3;
U64TO8_LE(out, b);
if (ctx->hash_size == SIPHASH_MIN_DIGEST_SIZE)
return 1;
v1 ^= 0xdd;
for (i = 0; i < ctx->drounds; ++i)
SIPROUND;
b = v0 ^ v1 ^ v2 ^ v3;
U64TO8_LE(out + 8, b);
return 1;
}