| /* sha256.c - an implementation of SHA-256/224 hash functions |
| * based on FIPS 180-3 (Federal Information Processing Standart). |
| * |
| * Copyright: 2010-2012 Aleksey Kravchenko <rhash.admin@gmail.com> |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so. |
| * |
| * This program 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. Use this program at your own risk! |
| */ |
| |
| #include <string.h> |
| #include "byte_order.h" |
| #include "sha256.h" |
| |
| /* SHA-224 and SHA-256 constants for 64 rounds. These words represent |
| * the first 32 bits of the fractional parts of the cube |
| * roots of the first 64 prime numbers. */ |
| static const unsigned rhash_k256[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 |
| }; |
| |
| /* The SHA256/224 functions defined by FIPS 180-3, 4.1.2 */ |
| /* Optimized version of Ch(x,y,z)=((x & y) | (~x & z)) */ |
| #define Ch(x,y,z) ((z) ^ ((x) & ((y) ^ (z)))) |
| /* Optimized version of Maj(x,y,z)=((x & y) ^ (x & z) ^ (y & z)) */ |
| #define Maj(x,y,z) (((x) & (y)) ^ ((z) & ((x) ^ (y)))) |
| |
| #define Sigma0(x) (ROTR32((x), 2) ^ ROTR32((x), 13) ^ ROTR32((x), 22)) |
| #define Sigma1(x) (ROTR32((x), 6) ^ ROTR32((x), 11) ^ ROTR32((x), 25)) |
| #define sigma0(x) (ROTR32((x), 7) ^ ROTR32((x), 18) ^ ((x) >> 3)) |
| #define sigma1(x) (ROTR32((x),17) ^ ROTR32((x), 19) ^ ((x) >> 10)) |
| |
| /* Recalculate element n-th of circular buffer W using formula |
| * W[n] = sigma1(W[n - 2]) + W[n - 7] + sigma0(W[n - 15]) + W[n - 16]; */ |
| #define RECALCULATE_W(W,n) (W[n] += \ |
| (sigma1(W[(n - 2) & 15]) + W[(n - 7) & 15] + sigma0(W[(n - 15) & 15]))) |
| |
| #define ROUND(a,b,c,d,e,f,g,h,k,data) { \ |
| unsigned T1 = h + Sigma1(e) + Ch(e,f,g) + k + (data); \ |
| d += T1, h = T1 + Sigma0(a) + Maj(a,b,c); } |
| #define ROUND_1_16(a,b,c,d,e,f,g,h,n) \ |
| ROUND(a,b,c,d,e,f,g,h, rhash_k256[n], W[n] = be2me_32(block[n])) |
| #define ROUND_17_64(a,b,c,d,e,f,g,h,n) \ |
| ROUND(a,b,c,d,e,f,g,h, k[n], RECALCULATE_W(W, n)) |
| |
| /** |
| * Initialize context before calculaing hash. |
| * |
| * @param ctx context to initialize |
| */ |
| void rhash_sha256_init(sha256_ctx *ctx) |
| { |
| /* Initial values. These words were obtained by taking the first 32 |
| * bits of the fractional parts of the square roots of the first |
| * eight prime numbers. */ |
| static const unsigned SHA256_H0[8] = { |
| 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, |
| 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 |
| }; |
| |
| ctx->length = 0; |
| ctx->digest_length = sha256_hash_size; |
| |
| /* initialize algorithm state */ |
| memcpy(ctx->hash, SHA256_H0, sizeof(ctx->hash)); |
| } |
| |
| /** |
| * Initialize context before calculaing hash. |
| * |
| * @param ctx context to initialize |
| */ |
| void rhash_sha224_init(struct sha256_ctx *ctx) |
| { |
| /* Initial values from FIPS 180-3. These words were obtained by taking |
| * bits from 33th to 64th of the fractional parts of the square |
| * roots of ninth through sixteenth prime numbers. */ |
| static const unsigned SHA224_H0[8] = { |
| 0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939, |
| 0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4 |
| }; |
| |
| ctx->length = 0; |
| ctx->digest_length = sha224_hash_size; |
| |
| memcpy(ctx->hash, SHA224_H0, sizeof(ctx->hash)); |
| } |
| |
| /** |
| * The core transformation. Process a 512-bit block. |
| * |
| * @param hash algorithm state |
| * @param block the message block to process |
| */ |
| static void rhash_sha256_process_block(unsigned hash[8], unsigned block[16]) |
| { |
| unsigned A, B, C, D, E, F, G, H; |
| unsigned W[16]; |
| const unsigned *k; |
| int i; |
| |
| A = hash[0], B = hash[1], C = hash[2], D = hash[3]; |
| E = hash[4], F = hash[5], G = hash[6], H = hash[7]; |
| |
| /* Compute SHA using alternate Method: FIPS 180-3 6.1.3 */ |
| ROUND_1_16(A, B, C, D, E, F, G, H, 0); |
| ROUND_1_16(H, A, B, C, D, E, F, G, 1); |
| ROUND_1_16(G, H, A, B, C, D, E, F, 2); |
| ROUND_1_16(F, G, H, A, B, C, D, E, 3); |
| ROUND_1_16(E, F, G, H, A, B, C, D, 4); |
| ROUND_1_16(D, E, F, G, H, A, B, C, 5); |
| ROUND_1_16(C, D, E, F, G, H, A, B, 6); |
| ROUND_1_16(B, C, D, E, F, G, H, A, 7); |
| ROUND_1_16(A, B, C, D, E, F, G, H, 8); |
| ROUND_1_16(H, A, B, C, D, E, F, G, 9); |
| ROUND_1_16(G, H, A, B, C, D, E, F, 10); |
| ROUND_1_16(F, G, H, A, B, C, D, E, 11); |
| ROUND_1_16(E, F, G, H, A, B, C, D, 12); |
| ROUND_1_16(D, E, F, G, H, A, B, C, 13); |
| ROUND_1_16(C, D, E, F, G, H, A, B, 14); |
| ROUND_1_16(B, C, D, E, F, G, H, A, 15); |
| |
| for (i = 16, k = &rhash_k256[16]; i < 64; i += 16, k += 16) { |
| ROUND_17_64(A, B, C, D, E, F, G, H, 0); |
| ROUND_17_64(H, A, B, C, D, E, F, G, 1); |
| ROUND_17_64(G, H, A, B, C, D, E, F, 2); |
| ROUND_17_64(F, G, H, A, B, C, D, E, 3); |
| ROUND_17_64(E, F, G, H, A, B, C, D, 4); |
| ROUND_17_64(D, E, F, G, H, A, B, C, 5); |
| ROUND_17_64(C, D, E, F, G, H, A, B, 6); |
| ROUND_17_64(B, C, D, E, F, G, H, A, 7); |
| ROUND_17_64(A, B, C, D, E, F, G, H, 8); |
| ROUND_17_64(H, A, B, C, D, E, F, G, 9); |
| ROUND_17_64(G, H, A, B, C, D, E, F, 10); |
| ROUND_17_64(F, G, H, A, B, C, D, E, 11); |
| ROUND_17_64(E, F, G, H, A, B, C, D, 12); |
| ROUND_17_64(D, E, F, G, H, A, B, C, 13); |
| ROUND_17_64(C, D, E, F, G, H, A, B, 14); |
| ROUND_17_64(B, C, D, E, F, G, H, A, 15); |
| } |
| |
| hash[0] += A, hash[1] += B, hash[2] += C, hash[3] += D; |
| hash[4] += E, hash[5] += F, hash[6] += G, hash[7] += H; |
| } |
| |
| /** |
| * Calculate message hash. |
| * Can be called repeatedly with chunks of the message to be hashed. |
| * |
| * @param ctx the algorithm context containing current hashing state |
| * @param msg message chunk |
| * @param size length of the message chunk |
| */ |
| void rhash_sha256_update(sha256_ctx *ctx, const unsigned char *msg, size_t size) |
| { |
| size_t index = (size_t)ctx->length & 63; |
| ctx->length += size; |
| |
| /* fill partial block */ |
| if (index) { |
| size_t left = sha256_block_size - index; |
| memcpy((char*)ctx->message + index, msg, (size < left ? size : left)); |
| if (size < left) return; |
| |
| /* process partial block */ |
| rhash_sha256_process_block(ctx->hash, (unsigned*)ctx->message); |
| msg += left; |
| size -= left; |
| } |
| while (size >= sha256_block_size) { |
| unsigned* aligned_message_block; |
| if (IS_ALIGNED_32(msg)) { |
| /* the most common case is processing of an already aligned message |
| without copying it */ |
| aligned_message_block = (unsigned*)msg; |
| } else { |
| memcpy(ctx->message, msg, sha256_block_size); |
| aligned_message_block = (unsigned*)ctx->message; |
| } |
| |
| rhash_sha256_process_block(ctx->hash, aligned_message_block); |
| msg += sha256_block_size; |
| size -= sha256_block_size; |
| } |
| if (size) { |
| memcpy(ctx->message, msg, size); /* save leftovers */ |
| } |
| } |
| |
| /** |
| * Store calculated hash into the given array. |
| * |
| * @param ctx the algorithm context containing current hashing state |
| * @param result calculated hash in binary form |
| */ |
| void rhash_sha256_final(sha256_ctx *ctx, unsigned char* result) |
| { |
| size_t index = ((unsigned)ctx->length & 63) >> 2; |
| unsigned shift = ((unsigned)ctx->length & 3) * 8; |
| |
| /* pad message and run for last block */ |
| |
| /* append the byte 0x80 to the message */ |
| ctx->message[index] &= le2me_32(~(0xFFFFFFFFu << shift)); |
| ctx->message[index++] ^= le2me_32(0x80u << shift); |
| |
| /* if no room left in the message to store 64-bit message length */ |
| if (index > 14) { |
| /* then fill the rest with zeros and process it */ |
| while (index < 16) { |
| ctx->message[index++] = 0; |
| } |
| rhash_sha256_process_block(ctx->hash, ctx->message); |
| index = 0; |
| } |
| while (index < 14) { |
| ctx->message[index++] = 0; |
| } |
| ctx->message[14] = be2me_32( (unsigned)(ctx->length >> 29) ); |
| ctx->message[15] = be2me_32( (unsigned)(ctx->length << 3) ); |
| rhash_sha256_process_block(ctx->hash, ctx->message); |
| |
| if (result) be32_copy(result, 0, ctx->hash, ctx->digest_length); |
| } |