#include <machine/rtems-bsd-kernel-space.h>
/*-
* Copyright (c) 2013 Andre Oppermann <andre@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
/*
* SipHash is a family of PRFs SipHash-c-d where the integer parameters c and d
* are the number of compression rounds and the number of finalization rounds.
* A compression round is identical to a finalization round and this round
* function is called SipRound. Given a 128-bit key k and a (possibly empty)
* byte string m, SipHash-c-d returns a 64-bit value SipHash-c-d(k; m).
*
* Implemented from the paper "SipHash: a fast short-input PRF", 2012.09.18,
* by Jean-Philippe Aumasson and Daniel J. Bernstein,
* Permanent Document ID b9a943a805fbfc6fde808af9fc0ecdfa
* https://131002.net/siphash/siphash.pdf
* https://131002.net/siphash/
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <rtems/bsd/sys/param.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/libkern.h>
#include <sys/endian.h>
#include <crypto/siphash/siphash.h>
static void SipRounds(SIPHASH_CTX *ctx, int final);
void
SipHash_InitX(SIPHASH_CTX *ctx, int rc, int rf)
{
ctx->v[0] = 0x736f6d6570736575ull;
ctx->v[1] = 0x646f72616e646f6dull;
ctx->v[2] = 0x6c7967656e657261ull;
ctx->v[3] = 0x7465646279746573ull;
ctx->buf.b64 = 0;
ctx->bytes = 0;
ctx->buflen = 0;
ctx->rounds_compr = rc;
ctx->rounds_final = rf;
ctx->initialized = 1;
}
void
SipHash_SetKey(SIPHASH_CTX *ctx, const uint8_t key[static SIPHASH_KEY_LENGTH])
{
uint64_t k[2];
KASSERT(ctx->v[0] == 0x736f6d6570736575ull &&
ctx->initialized == 1,
("%s: context %p not properly initialized", __func__, ctx));
k[0] = le64dec(&key[0]);
k[1] = le64dec(&key[8]);
ctx->v[0] ^= k[0];
ctx->v[1] ^= k[1];
ctx->v[2] ^= k[0];
ctx->v[3] ^= k[1];
ctx->initialized = 2;
}
static size_t
SipBuf(SIPHASH_CTX *ctx, const uint8_t **src, size_t len, int final)
{
size_t x = 0;
KASSERT((!final && len > 0) || (final && len == 0),
("%s: invalid parameters", __func__));
if (!final) {
x = MIN(len, sizeof(ctx->buf.b64) - ctx->buflen);
bcopy(*src, &ctx->buf.b8[ctx->buflen], x);
ctx->buflen += x;
*src += x;
} else
ctx->buf.b8[7] = (uint8_t)ctx->bytes;
if (ctx->buflen == 8 || final) {
ctx->v[3] ^= le64toh(ctx->buf.b64);
SipRounds(ctx, 0);
ctx->v[0] ^= le64toh(ctx->buf.b64);
ctx->buf.b64 = 0;
ctx->buflen = 0;
}
return (x);
}
void
SipHash_Update(SIPHASH_CTX *ctx, const void *src, size_t len)
{
uint64_t m;
const uint64_t *p;
const uint8_t *s;
size_t rem;
KASSERT(ctx->initialized == 2,
("%s: context %p not properly initialized", __func__, ctx));
s = src;
ctx->bytes += len;
/*
* Push length smaller than block size into buffer or
* fill up the buffer if there is already something
* in it.
*/
if (ctx->buflen > 0 || len < 8)
len -= SipBuf(ctx, &s, len, 0);
if (len == 0)
return;
rem = len & 0x7;
len >>= 3;
/* Optimze for 64bit aligned/unaligned access. */
if (((uintptr_t)s & 0x7) == 0) {
for (p = (const uint64_t *)s; len > 0; len--, p++) {
m = le64toh(*p);
ctx->v[3] ^= m;
SipRounds(ctx, 0);
ctx->v[0] ^= m;
}
s = (const uint8_t *)p;
} else {
for (; len > 0; len--, s += 8) {
m = le64dec(s);
ctx->v[3] ^= m;
SipRounds(ctx, 0);
ctx->v[0] ^= m;
}
}
/* Push remainder into buffer. */
if (rem > 0)
(void)SipBuf(ctx, &s, rem, 0);
}
void
SipHash_Final(uint8_t dst[static SIPHASH_DIGEST_LENGTH], SIPHASH_CTX *ctx)
{
uint64_t r;
KASSERT(ctx->initialized == 2,
("%s: context %p not properly initialized", __func__, ctx));
r = SipHash_End(ctx);
le64enc(dst, r);
}
uint64_t
SipHash_End(SIPHASH_CTX *ctx)
{
uint64_t r;
KASSERT(ctx->initialized == 2,
("%s: context %p not properly initialized", __func__, ctx));
SipBuf(ctx, NULL, 0, 1);
ctx->v[2] ^= 0xff;
SipRounds(ctx, 1);
r = (ctx->v[0] ^ ctx->v[1]) ^ (ctx->v[2] ^ ctx->v[3]);
bzero(ctx, sizeof(*ctx));
return (r);
}
uint64_t
SipHashX(SIPHASH_CTX *ctx, int rc, int rf,
const uint8_t key[static SIPHASH_KEY_LENGTH], const void *src, size_t len)
{
SipHash_InitX(ctx, rc, rf);
SipHash_SetKey(ctx, key);
SipHash_Update(ctx, src, len);
return (SipHash_End(ctx));
}
#define SIP_ROTL(x, b) (uint64_t)(((x) << (b)) | ( (x) >> (64 - (b))))
static void
SipRounds(SIPHASH_CTX *ctx, int final)
{
int rounds;
if (!final)
rounds = ctx->rounds_compr;
else
rounds = ctx->rounds_final;
while (rounds--) {
ctx->v[0] += ctx->v[1];
ctx->v[2] += ctx->v[3];
ctx->v[1] = SIP_ROTL(ctx->v[1], 13);
ctx->v[3] = SIP_ROTL(ctx->v[3], 16);
ctx->v[1] ^= ctx->v[0];
ctx->v[3] ^= ctx->v[2];
ctx->v[0] = SIP_ROTL(ctx->v[0], 32);
ctx->v[2] += ctx->v[1];
ctx->v[0] += ctx->v[3];
ctx->v[1] = SIP_ROTL(ctx->v[1], 17);
ctx->v[3] = SIP_ROTL(ctx->v[3], 21);
ctx->v[1] ^= ctx->v[2];
ctx->v[3] ^= ctx->v[0];
ctx->v[2] = SIP_ROTL(ctx->v[2], 32);
}
}
