| /////////////////////////////////////////////////////////////////////////////// |
| // |
| /// \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; |
| } |