diff options
Diffstat (limited to 'src/liblzma/check/sha256.c')
| -rw-r--r-- | src/liblzma/check/sha256.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/src/liblzma/check/sha256.c b/src/liblzma/check/sha256.c new file mode 100644 index 00000000..8e3d375a --- /dev/null +++ b/src/liblzma/check/sha256.c @@ -0,0 +1,203 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file sha256.c +/// \brief SHA256 +// +// Based on the public domain code found from Wei Dai's Crypto++ library +// version 5.5.1: http://www.cryptopp.com/ +// This code has been put into the public domain. +// +/// \todo Crypto++ has x86 ASM optimizations. They use SSE so if they +/// are imported to liblzma, SSE instructions need to be used +/// conditionally to keep the code working on older boxes. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "check.h" + +#ifndef WORDS_BIGENDIAN +# include "check_byteswap.h" +#endif + +// At least on x86, GCC is able to optimize this to a rotate instruction. +#define rotr_32(num, amount) ((num) >> (amount) | (num) << (32 - (amount))) + +#define blk0(i) (W[i] = data[i]) +#define blk2(i) (W[i & 15] += s1(W[(i - 2) & 15]) + W[(i - 7) & 15] \ + + s0(W[(i - 15) & 15])) + +#define Ch(x, y, z) (z ^ (x & (y ^ z))) +#define Maj(x, y, z) ((x & y) | (z & (x | y))) + +#define a(i) T[(0 - i) & 7] +#define b(i) T[(1 - i) & 7] +#define c(i) T[(2 - i) & 7] +#define d(i) T[(3 - i) & 7] +#define e(i) T[(4 - i) & 7] +#define f(i) T[(5 - i) & 7] +#define g(i) T[(6 - i) & 7] +#define h(i) T[(7 - i) & 7] + +#define R(i) \ + h(i) += S1(e(i)) + Ch(e(i), f(i), g(i)) + SHA256_K[i + j] \ + + (j ? blk2(i) : blk0(i)); \ + d(i) += h(i); \ + h(i) += S0(a(i)) + Maj(a(i), b(i), c(i)) + +#define S0(x) (rotr_32(x, 2) ^ rotr_32(x, 13) ^ rotr_32(x, 22)) +#define S1(x) (rotr_32(x, 6) ^ rotr_32(x, 11) ^ rotr_32(x, 25)) +#define s0(x) (rotr_32(x, 7) ^ rotr_32(x, 18) ^ (x >> 3)) +#define s1(x) (rotr_32(x, 17) ^ rotr_32(x, 19) ^ (x >> 10)) + + +static const uint32_t SHA256_K[64] = { + 0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, + 0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5, + 0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3, + 0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174, + 0xE49B69C1, 0xEFBE4786, 0x0FC19DC6, 0x240CA1CC, + 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA, + 0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, + 0xC6E00BF3, 0xD5A79147, 0x06CA6351, 0x14292967, + 0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13, + 0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85, + 0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3, + 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070, + 0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, + 0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3, + 0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208, + 0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2, +}; + + +static void +transform(uint32_t state[static 8], const uint32_t data[static 16]) +{ + uint32_t W[16]; + uint32_t T[8]; + + // Copy state[] to working vars. + memcpy(T, state, sizeof(T)); + + // 64 operations, partially loop unrolled + for (unsigned int j = 0; j < 64; j += 16) { + R( 0); R( 1); R( 2); R( 3); + R( 4); R( 5); R( 6); R( 7); + R( 8); R( 9); R(10); R(11); + R(12); R(13); R(14); R(15); + } + + // Add the working vars back into state[]. + state[0] += a(0); + state[1] += b(0); + state[2] += c(0); + state[3] += d(0); + state[4] += e(0); + state[5] += f(0); + state[6] += g(0); + state[7] += h(0); +} + + +static void +process(lzma_sha256 *sha256) +{ +#ifdef WORDS_BIGENDIAN + transform(sha256->state, (uint32_t *)(sha256->buffer)); + +#else + uint32_t data[16]; + + for (size_t i = 0; i < 16; ++i) + data[i] = bswap_32(*((uint32_t*)(sha256->buffer) + i)); + + transform(sha256->state, data); +#endif + + return; +} + + +extern void +lzma_sha256_init(lzma_sha256 *sha256) +{ + static const uint32_t s[8] = { + 0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, + 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19, + }; + + memcpy(sha256->state, s, sizeof(s)); + sha256->size = 0; + + return; +} + + +extern void +lzma_sha256_update(const uint8_t *buf, size_t size, lzma_sha256 *sha256) +{ + // Copy the input data into a properly aligned temporary buffer. + // This way we can be called with arbitrarily sized buffers + // (no need to be multiple of 64 bytes), and the code works also + // on architectures that don't allow unaligned memory access. + while (size > 0) { + const size_t copy_start = sha256->size & 0x3F; + size_t copy_size = 64 - copy_start; + if (copy_size > size) + copy_size = size; + + memcpy(sha256->buffer + copy_start, buf, copy_size); + + buf += copy_size; + size -= copy_size; + sha256->size += copy_size; + + if ((sha256->size & 0x3F) == 0) + process(sha256); + } + + return; +} + + +extern void +lzma_sha256_finish(lzma_sha256 *sha256) +{ + // Add padding as described in RFC 3174 (it describes SHA-1 but + // the same padding style is used for SHA-256 too). + size_t pos = sha256->size & 0x3F; + sha256->buffer[pos++] = 0x80; + + while (pos != 64 - 8) { + if (pos == 64) { + process(sha256); + pos = 0; + } + + sha256->buffer[pos++] = 0x00; + } + + // Convert the message size from bytes to bits. + sha256->size *= 8; + +#ifdef WORDS_BIGENDIAN + *(uint64_t *)(sha256->buffer + 64 - 8) = sha256->size; +#else + *(uint64_t *)(sha256->buffer + 64 - 8) = bswap_64(sha256->size); +#endif + + process(sha256); + + for (size_t i = 0; i < 8; ++i) +#ifdef WORDS_BIGENDIAN + ((uint32_t *)(sha256->buffer))[i] = sha256->state[i]; +#else + ((uint32_t *)(sha256->buffer))[i] = bswap_32(sha256->state[i]); +#endif + + return; +} |