/* SHA-256 and SHA-512 implementation based on code by Oliver Gay * under a BSD-style license. See below. */ /* * FIPS 180-2 SHA-224/256/384/512 implementation * Last update: 02/02/2007 * Issue date: 04/30/2005 * * Copyright (C) 2005, 2007 Olivier Gay * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "sha256.h" #include "util.h" #define SHFR(x, n) (x >> n) #define ROTR(x, n) ((x >> n) | (x << ((sizeof(x) << 3) - n))) #define ROTL(x, n) ((x << n) | (x >> ((sizeof(x) << 3) - n))) #define CH(x, y, z) ((x & y) ^ (~x & z)) #define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z)) #define SHA256_F1(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22)) #define SHA256_F2(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25)) #define SHA256_F3(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHFR(x, 3)) #define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10)) #define UNPACK32(x, str) \ { \ *((str) + 3) = (uint8_t) ((x)); \ *((str) + 2) = (uint8_t) ((x) >> 8); \ *((str) + 1) = (uint8_t) ((x) >> 16); \ *((str) + 0) = (uint8_t) ((x) >> 24); \ } #define PACK32(str, x) \ { \ *(x) = ((uint32_t) *((str) + 3)) \ | ((uint32_t) *((str) + 2) << 8) \ | ((uint32_t) *((str) + 1) << 16) \ | ((uint32_t) *((str) + 0) << 24); \ } /* Macros used for loops unrolling */ #define SHA256_SCR(i) \ { \ w[i] = SHA256_F4(w[i - 2]) + w[i - 7] \ + SHA256_F3(w[i - 15]) + w[i - 16]; \ } #define SHA256_EXP(a, b, c, d, e, f, g, h, j) \ { \ t1 = wv[h] + SHA256_F2(wv[e]) + CH(wv[e], wv[f], wv[g]) \ + sha256_k[j] + w[j]; \ t2 = SHA256_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]); \ wv[d] += t1; \ wv[h] = t1 + t2; \ } static const uint32_t sha256_h0[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19}; 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}; void SHA256_init(struct sha256_ctx *ctx) { int i; for (i = 0; i < 8; i++) ctx->h[i] = sha256_h0[i]; ctx->len = 0; ctx->tot_len = 0; } static void SHA256_transform(struct sha256_ctx *ctx, const uint8_t *message, unsigned int block_nb) { /* Note: this function requires a considerable amount of stack */ uint32_t w[64]; uint32_t wv[8]; uint32_t t1, t2; const unsigned char *sub_block; int i, j; for (i = 0; i < (int) block_nb; i++) { sub_block = message + (i << 6); for (j = 0; j < 16; j++) PACK32(&sub_block[j << 2], &w[j]); #ifdef CONFIG_SHA256_UNROLLED for (j = 16; j < 64; j += 8) { SHA256_SCR(j); SHA256_SCR(j+1); SHA256_SCR(j+2); SHA256_SCR(j+3); SHA256_SCR(j+4); SHA256_SCR(j+5); SHA256_SCR(j+6); SHA256_SCR(j+7); } #else for (j = 16; j < 64; j++) SHA256_SCR(j); #endif for (j = 0; j < 8; j++) wv[j] = ctx->h[j]; #ifdef CONFIG_SHA256_UNROLLED for (j = 0; j < 64; j += 8) { SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, j); SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, j+1); SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, j+2); SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, j+3); SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, j+4); SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, j+5); SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, j+6); SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, j+7); } #else for (j = 0; j < 64; j++) { t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6]) + sha256_k[j] + w[j]; t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]); wv[7] = wv[6]; wv[6] = wv[5]; wv[5] = wv[4]; wv[4] = wv[3] + t1; wv[3] = wv[2]; wv[2] = wv[1]; wv[1] = wv[0]; wv[0] = t1 + t2; } #endif for (j = 0; j < 8; j++) ctx->h[j] += wv[j]; } } void SHA256_update(struct sha256_ctx *ctx, const uint8_t *data, uint32_t len) { unsigned int block_nb; unsigned int new_len, rem_len, tmp_len; const uint8_t *shifted_data; tmp_len = SHA256_BLOCK_SIZE - ctx->len; rem_len = len < tmp_len ? len : tmp_len; memcpy(&ctx->block[ctx->len], data, rem_len); if (ctx->len + len < SHA256_BLOCK_SIZE) { ctx->len += len; return; } new_len = len - rem_len; block_nb = new_len / SHA256_BLOCK_SIZE; shifted_data = data + rem_len; SHA256_transform(ctx, ctx->block, 1); SHA256_transform(ctx, shifted_data, block_nb); rem_len = new_len % SHA256_BLOCK_SIZE; memcpy(ctx->block, &shifted_data[block_nb << 6], rem_len); ctx->len = rem_len; ctx->tot_len += (block_nb + 1) << 6; } /* * Specialized SHA256_init + SHA256_update that takes the first data block of * size SHA256_BLOCK_SIZE as input. */ static void SHA256_init_1b(struct sha256_ctx *ctx, const uint8_t *data) { int i; for (i = 0; i < 8; i++) ctx->h[i] = sha256_h0[i]; SHA256_transform(ctx, data, 1); ctx->len = 0; ctx->tot_len = SHA256_BLOCK_SIZE; } uint8_t *SHA256_final(struct sha256_ctx *ctx) { unsigned int block_nb; unsigned int pm_len; unsigned int len_b; int i; block_nb = (1 + ((SHA256_BLOCK_SIZE - 9) < (ctx->len % SHA256_BLOCK_SIZE))); len_b = (ctx->tot_len + ctx->len) << 3; pm_len = block_nb << 6; memset(ctx->block + ctx->len, 0, pm_len - ctx->len); ctx->block[ctx->len] = 0x80; UNPACK32(len_b, ctx->block + pm_len - 4); SHA256_transform(ctx, ctx->block, block_nb); for (i = 0; i < 8; i++) UNPACK32(ctx->h[i], &ctx->buf[i << 2]); return ctx->buf; } static void hmac_SHA256_step(uint8_t *output, uint8_t mask, const uint8_t *key, const int key_len, const uint8_t *data, const int data_len) { struct sha256_ctx ctx; uint8_t *key_pad = ctx.block; uint8_t *tmp; int i; /* key_pad = key (zero-padded) ^ mask */ memset(key_pad, mask, SHA256_BLOCK_SIZE); for (i = 0; i < key_len; i++) key_pad[i] ^= key[i]; /* tmp = hash(key_pad || message) */ SHA256_init_1b(&ctx, key_pad); SHA256_update(&ctx, data, data_len); tmp = SHA256_final(&ctx); memcpy(output, tmp, SHA256_DIGEST_SIZE); } void hmac_SHA256(uint8_t *output, const uint8_t *key, const int key_len, const uint8_t *message, const int message_len) { /* This code does not support key_len > block_size. */ ASSERT(key_len <= SHA256_BLOCK_SIZE); /* * i_key_pad = key (zero-padded) ^ 0x36 * output = hash(i_key_pad || message) * (Use output as temporary buffer) */ hmac_SHA256_step(output, 0x36, key, key_len, message, message_len); /* * o_key_pad = key (zero-padded) ^ 0x5c * output = hash(o_key_pad || output) */ hmac_SHA256_step(output, 0x5c, key, key_len, output, SHA256_DIGEST_SIZE); }