Mercurial > repos > blastem
view hash.c @ 1925:039553703c20
Don't apply address and cd register changes to the 'live' registers until pending flag is cleared, but do preserve the upper address bits in the latch. Fixes regression in Overdrive 2 while preserving fix to Mona in 344 bytes
author | Michael Pavone <pavone@retrodev.com> |
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date | Mon, 13 Apr 2020 20:43:25 -0700 |
parents | 5ceb316c479a |
children | 0111c8344477 |
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#include <stdint.h> #include <string.h> //NOTE: This is only intended for use in file identification //Please do not use this in a cryptographic setting as no attempts have been //made at avoiding side channel attacks static uint32_t rotleft(uint32_t val, uint32_t shift) { return val << shift | val >> (32-shift); } static void sha1_step(uint32_t *state, uint32_t f, uint32_t k, uint32_t w) { uint32_t tmp = rotleft(state[0], 5) + f + state[4] + k + w; state[4] = state[3]; state[3] = state[2]; state[2] = rotleft(state[1], 30); state[1] = state[0]; state[0] = tmp; } static void sha1_chunk(uint8_t *chunk, uint32_t *hash) { uint32_t state[5], w[80]; memcpy(state, hash, sizeof(state)); for (uint32_t src = 0; src < 64; src += 4) { w[src >> 2] = chunk[src] << 24 | chunk[src+1] << 16 | chunk[src+2] << 8 | chunk[src+3]; } for (uint32_t cur = 16; cur < 80; cur++) { w[cur] = rotleft(w[cur-3] ^ w[cur-8] ^ w[cur-14] ^ w[cur-16], 1); } for (uint32_t cur = 0; cur < 20; cur++) { sha1_step(state, (state[1] & state[2]) | ((~state[1]) & state[3]), 0x5A827999, w[cur]); } for (uint32_t cur = 20; cur < 40; cur++) { sha1_step(state, state[1] ^ state[2] ^ state[3], 0x6ED9EBA1, w[cur]); } for (uint32_t cur = 40; cur < 60; cur++) { sha1_step(state, (state[1] & state[2]) | (state[1] & state[3]) | (state[2] & state[3]), 0x8F1BBCDC, w[cur]); } for (uint32_t cur = 60; cur < 80; cur++) { sha1_step(state, state[1] ^ state[2] ^ state[3], 0xCA62C1D6, w[cur]); } for (uint32_t i = 0; i < 5; i++) { hash[i] += state[i]; } } void sha1(uint8_t *data, uint64_t size, uint8_t *out) { uint32_t hash[5] = {0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0}; uint8_t last[128]; uint32_t last_size = 0; if ((size & 63) != 0) { for (uint32_t src = size - (size & 63); src < size; src++) { last[last_size++] = data[src]; } } uint64_t bitsize = size * 8; size -= last_size; last[last_size++] = 0x80; while ((last_size & 63) != 56) { last[last_size++] = 0; } last[last_size++] = bitsize >> 56; last[last_size++] = bitsize >> 48; last[last_size++] = bitsize >> 40; last[last_size++] = bitsize >> 32; last[last_size++] = bitsize >> 24; last[last_size++] = bitsize >> 16; last[last_size++] = bitsize >> 8; last[last_size++] = bitsize; for (uint64_t cur = 0; cur < size; cur += 64) { sha1_chunk(data + cur, hash); } for (uint64_t cur = 0; cur < last_size; cur += 64) { sha1_chunk(last + cur, hash); } for (uint32_t cur = 0; cur < 20; cur += 4) { uint32_t val = hash[cur >> 2]; out[cur] = val >> 24; out[cur+1] = val >> 16; out[cur+2] = val >> 8; out[cur+3] = val; } }