diff options
Diffstat (limited to 'src/basic/siphash24.c')
-rw-r--r-- | src/basic/siphash24.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/src/basic/siphash24.c b/src/basic/siphash24.c new file mode 100644 index 0000000..b614ecf --- /dev/null +++ b/src/basic/siphash24.c @@ -0,0 +1,201 @@ +/* SPDX-License-Identifier: CC0-1.0 */ + +/* + SipHash reference C implementation + + Written in 2012 by + Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com> + 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 <https://creativecommons.org/publicdomain/zero/1.0/>. + + (Minimal changes made by Lennart Poettering, to make clean for inclusion in systemd) + (Refactored by Tom Gundersen to split up in several functions and follow systemd + coding style) +*/ + +#include <stdio.h> + +#include "macro.h" +#include "siphash24.h" +#include "unaligned.h" + +static uint64_t rotate_left(uint64_t x, uint8_t b) { + assert(b < 64); + + return (x << b) | (x >> (64 - b)); +} + +static void sipround(struct siphash *state) { + assert(state); + + state->v0 += state->v1; + state->v1 = rotate_left(state->v1, 13); + state->v1 ^= state->v0; + state->v0 = rotate_left(state->v0, 32); + state->v2 += state->v3; + state->v3 = rotate_left(state->v3, 16); + state->v3 ^= state->v2; + state->v0 += state->v3; + state->v3 = rotate_left(state->v3, 21); + state->v3 ^= state->v0; + state->v2 += state->v1; + state->v1 = rotate_left(state->v1, 17); + state->v1 ^= state->v2; + state->v2 = rotate_left(state->v2, 32); +} + +void siphash24_init(struct siphash *state, const uint8_t k[static 16]) { + uint64_t k0, k1; + + assert(state); + assert(k); + + k0 = unaligned_read_le64(k); + k1 = unaligned_read_le64(k + 8); + + *state = (struct siphash) { + /* "somepseudorandomlygeneratedbytes" */ + .v0 = 0x736f6d6570736575ULL ^ k0, + .v1 = 0x646f72616e646f6dULL ^ k1, + .v2 = 0x6c7967656e657261ULL ^ k0, + .v3 = 0x7465646279746573ULL ^ k1, + .padding = 0, + .inlen = 0, + }; +} + +void siphash24_compress(const void *_in, size_t inlen, struct siphash *state) { + + const uint8_t *in = ASSERT_PTR(_in); + const uint8_t *end = in + inlen; + size_t left = state->inlen & 7; + uint64_t m; + + assert(state); + + /* Update total length */ + state->inlen += inlen; + + /* If padding exists, fill it out */ + if (left > 0) { + for ( ; in < end && left < 8; in ++, left ++) + state->padding |= ((uint64_t) *in) << (left * 8); + + if (in == end && left < 8) + /* We did not have enough input to fill out the padding completely */ + return; + +#if ENABLE_DEBUG_SIPHASH + printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0); + printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1); + printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2); + printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3); + printf("(%3zu) compress padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t)state->padding); +#endif + + state->v3 ^= state->padding; + sipround(state); + sipround(state); + state->v0 ^= state->padding; + + state->padding = 0; + } + + end -= (state->inlen % sizeof(uint64_t)); + + for ( ; in < end; in += 8) { + m = unaligned_read_le64(in); +#if ENABLE_DEBUG_SIPHASH + printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0); + printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1); + printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2); + printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3); + printf("(%3zu) compress %08x %08x\n", state->inlen, (uint32_t) (m >> 32), (uint32_t) m); +#endif + state->v3 ^= m; + sipround(state); + sipround(state); + state->v0 ^= m; + } + + left = state->inlen & 7; + switch (left) { + case 7: + state->padding |= ((uint64_t) in[6]) << 48; + _fallthrough_; + case 6: + state->padding |= ((uint64_t) in[5]) << 40; + _fallthrough_; + case 5: + state->padding |= ((uint64_t) in[4]) << 32; + _fallthrough_; + case 4: + state->padding |= ((uint64_t) in[3]) << 24; + _fallthrough_; + case 3: + state->padding |= ((uint64_t) in[2]) << 16; + _fallthrough_; + case 2: + state->padding |= ((uint64_t) in[1]) << 8; + _fallthrough_; + case 1: + state->padding |= ((uint64_t) in[0]); + _fallthrough_; + case 0: + break; + } +} + +uint64_t siphash24_finalize(struct siphash *state) { + uint64_t b; + + assert(state); + + b = state->padding | (((uint64_t) state->inlen) << 56); + +#if ENABLE_DEBUG_SIPHASH + printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0); + printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1); + printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2); + printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3); + printf("(%3zu) padding %08x %08x\n", state->inlen, (uint32_t) (state->padding >> 32), (uint32_t) state->padding); +#endif + + state->v3 ^= b; + sipround(state); + sipround(state); + state->v0 ^= b; + +#if ENABLE_DEBUG_SIPHASH + printf("(%3zu) v0 %08x %08x\n", state->inlen, (uint32_t) (state->v0 >> 32), (uint32_t) state->v0); + printf("(%3zu) v1 %08x %08x\n", state->inlen, (uint32_t) (state->v1 >> 32), (uint32_t) state->v1); + printf("(%3zu) v2 %08x %08x\n", state->inlen, (uint32_t) (state->v2 >> 32), (uint32_t) state->v2); + printf("(%3zu) v3 %08x %08x\n", state->inlen, (uint32_t) (state->v3 >> 32), (uint32_t) state->v3); +#endif + state->v2 ^= 0xff; + + sipround(state); + sipround(state); + sipround(state); + sipround(state); + + return state->v0 ^ state->v1 ^ state->v2 ^ state->v3; +} + +uint64_t siphash24(const void *in, size_t inlen, const uint8_t k[static 16]) { + struct siphash state; + + assert(in); + assert(k); + + siphash24_init(&state, k); + siphash24_compress(in, inlen, &state); + + return siphash24_finalize(&state); +} |