/* sha256.c - an implementation of SHA-256/224 hash functions * based on FIPS 180-3 (Federal Information Processing Standart). * * Copyright (c) 2010, Aleksey Kravchenko * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR * PERFORMANCE OF THIS SOFTWARE. */ #include #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); }