/*- * Copyright (c) 2013 Andre Oppermann * 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 #include #include #include #include #include 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); } }