/*- * Copyright (c) 2005-2013 Colin Percival * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 "cryb/impl.h" #include #include #include #include /* * Encode a length len/4 vector of (uint32_t) into a length len vector of * (uint8_t) in big-endian form. Assumes len is a multiple of 4. */ static void be32enc_vect(uint8_t *dst, const uint32_t *src, size_t len) { size_t i; for (i = 0; i < len / 4; i++) be32enc(dst + i * 4, src[i]); } /* * Decode a big-endian length len vector of (uint8_t) into a length * len/4 vector of (uint32_t). Assumes len is a multiple of 4. */ static void be32dec_vect(uint32_t *dst, const uint8_t *src, size_t len) { size_t i; for (i = 0; i < len / 4; i++) dst[i] = be32dec(src + i * 4); } /* Elementary functions used by SHA256 */ #define Ch(x, y, z) ((x & (y ^ z)) ^ z) #define Maj(x, y, z) ((x & (y | z)) | (y & z)) #define SHR(x, n) (x >> n) #define ROTR(x, n) ((x >> n) | (x << (32 - n))) #define S0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22)) #define S1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25)) #define s0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3)) #define s1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10)) /* SHA256 round function */ #define RND(a, b, c, d, e, f, g, h, k) \ t0 = h + S1(e) + Ch(e, f, g) + k; \ t1 = S0(a) + Maj(a, b, c); \ d += t0; \ h = t0 + t1; /* Adjusted round function for rotating state */ #define RNDr(S, W, i, k) \ RND(S[(64 - i) % 8], S[(65 - i) % 8], \ S[(66 - i) % 8], S[(67 - i) % 8], \ S[(68 - i) % 8], S[(69 - i) % 8], \ S[(70 - i) % 8], S[(71 - i) % 8], \ W[i] + k) /* * SHA256 block compression function. The 256-bit state is transformed via * the 512-bit input block to produce a new state. */ static void sha256_Transform(uint32_t * state, const uint8_t block[64]) { uint32_t W[64]; uint32_t S[8]; uint32_t t0, t1; int i; /* 1. Prepare message schedule W. */ be32dec_vect(W, block, 64); for (i = 16; i < 64; i++) W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16]; /* 2. Initialize working variables. */ memcpy(S, state, 32); /* 3. Mix. */ RNDr(S, W, 0, 0x428a2f98); RNDr(S, W, 1, 0x71374491); RNDr(S, W, 2, 0xb5c0fbcf); RNDr(S, W, 3, 0xe9b5dba5); RNDr(S, W, 4, 0x3956c25b); RNDr(S, W, 5, 0x59f111f1); RNDr(S, W, 6, 0x923f82a4); RNDr(S, W, 7, 0xab1c5ed5); RNDr(S, W, 8, 0xd807aa98); RNDr(S, W, 9, 0x12835b01); RNDr(S, W, 10, 0x243185be); RNDr(S, W, 11, 0x550c7dc3); RNDr(S, W, 12, 0x72be5d74); RNDr(S, W, 13, 0x80deb1fe); RNDr(S, W, 14, 0x9bdc06a7); RNDr(S, W, 15, 0xc19bf174); RNDr(S, W, 16, 0xe49b69c1); RNDr(S, W, 17, 0xefbe4786); RNDr(S, W, 18, 0x0fc19dc6); RNDr(S, W, 19, 0x240ca1cc); RNDr(S, W, 20, 0x2de92c6f); RNDr(S, W, 21, 0x4a7484aa); RNDr(S, W, 22, 0x5cb0a9dc); RNDr(S, W, 23, 0x76f988da); RNDr(S, W, 24, 0x983e5152); RNDr(S, W, 25, 0xa831c66d); RNDr(S, W, 26, 0xb00327c8); RNDr(S, W, 27, 0xbf597fc7); RNDr(S, W, 28, 0xc6e00bf3); RNDr(S, W, 29, 0xd5a79147); RNDr(S, W, 30, 0x06ca6351); RNDr(S, W, 31, 0x14292967); RNDr(S, W, 32, 0x27b70a85); RNDr(S, W, 33, 0x2e1b2138); RNDr(S, W, 34, 0x4d2c6dfc); RNDr(S, W, 35, 0x53380d13); RNDr(S, W, 36, 0x650a7354); RNDr(S, W, 37, 0x766a0abb); RNDr(S, W, 38, 0x81c2c92e); RNDr(S, W, 39, 0x92722c85); RNDr(S, W, 40, 0xa2bfe8a1); RNDr(S, W, 41, 0xa81a664b); RNDr(S, W, 42, 0xc24b8b70); RNDr(S, W, 43, 0xc76c51a3); RNDr(S, W, 44, 0xd192e819); RNDr(S, W, 45, 0xd6990624); RNDr(S, W, 46, 0xf40e3585); RNDr(S, W, 47, 0x106aa070); RNDr(S, W, 48, 0x19a4c116); RNDr(S, W, 49, 0x1e376c08); RNDr(S, W, 50, 0x2748774c); RNDr(S, W, 51, 0x34b0bcb5); RNDr(S, W, 52, 0x391c0cb3); RNDr(S, W, 53, 0x4ed8aa4a); RNDr(S, W, 54, 0x5b9cca4f); RNDr(S, W, 55, 0x682e6ff3); RNDr(S, W, 56, 0x748f82ee); RNDr(S, W, 57, 0x78a5636f); RNDr(S, W, 58, 0x84c87814); RNDr(S, W, 59, 0x8cc70208); RNDr(S, W, 60, 0x90befffa); RNDr(S, W, 61, 0xa4506ceb); RNDr(S, W, 62, 0xbef9a3f7); RNDr(S, W, 63, 0xc67178f2); /* 4. Mix local working variables into global state. */ for (i = 0; i < 8; i++) state[i] += S[i]; /* Clean the stack. */ memset(W, 0, 256); memset(S, 0, 32); t0 = t1 = 0; } static uint8_t PAD[64] = { 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; /* Add padding and terminating bit-count. */ static void sha256_pad(sha256_ctx * ctx) { uint8_t len[8]; uint32_t r, plen; /* * Convert length to a vector of bytes -- we do this now rather * than later because the length will change after we pad. */ be64enc(len, ctx->count); /* Add 1--64 bytes so that the resulting length is 56 mod 64. */ r = (ctx->count >> 3) & 0x3f; plen = (r < 56) ? (56 - r) : (120 - r); sha256_update(ctx, PAD, (size_t)plen); /* Add the terminating bit-count. */ sha256_update(ctx, len, 8); } /** * sha256_init(ctx): * Initialize the SHA256 context ${ctx}. */ void sha256_init(sha256_ctx * ctx) { /* Zero bits processed so far. */ ctx->count = 0; /* Magic initialization constants. */ ctx->state[0] = 0x6A09E667; ctx->state[1] = 0xBB67AE85; ctx->state[2] = 0x3C6EF372; ctx->state[3] = 0xA54FF53A; ctx->state[4] = 0x510E527F; ctx->state[5] = 0x9B05688C; ctx->state[6] = 0x1F83D9AB; ctx->state[7] = 0x5BE0CD19; } /** * sha256_update(ctx, in, len): * Input ${len} bytes from ${in} into the SHA256 context ${ctx}. */ void sha256_update(sha256_ctx * ctx, const void *in, size_t len) { uint32_t r; const uint8_t *src = in; /* Return immediately if we have nothing to do. */ if (len == 0) return; /* Number of bytes left in the buffer from previous updates. */ r = (ctx->count >> 3) & 0x3f; /* Update number of bits. */ ctx->count += (uint64_t)(len) << 3; /* Handle the case where we don't need to perform any transforms. */ if (len < 64 - r) { memcpy(&ctx->buf[r], src, len); return; } /* Finish the current block. */ memcpy(&ctx->buf[r], src, 64 - r); sha256_Transform(ctx->state, ctx->buf); src += 64 - r; len -= 64 - r; /* Perform complete blocks. */ while (len >= 64) { sha256_Transform(ctx->state, src); src += 64; len -= 64; } /* Copy left over data into buffer. */ memcpy(ctx->buf, src, len); } /** * sha256_final(ctx, digest): * Output the SHA256 hash of the data input to the context ${ctx} into the * buffer ${digest}. */ void sha256_final(sha256_ctx * ctx, uint8_t *digest) { /* Add padding. */ sha256_pad(ctx); /* Write the hash. */ be32enc_vect(digest, ctx->state, SHA256_DIGEST_LEN); /* Clear the context state. */ memset(ctx, 0, sizeof(*ctx)); } /** * sha256_complete(in, len, digest): * Compute the SHA256 hash of ${len} bytes from $in} and write it to ${digest}. */ void sha256_complete(const void * in, size_t len, uint8_t *digest) { sha256_ctx ctx; sha256_init(&ctx); sha256_update(&ctx, in, len); sha256_final(&ctx, digest); } #if 0 /** * PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen): * Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and * write the output to buf. The value dkLen must be at most 32 * (2^32 - 1). */ void pbkdf2_sha256(const uint8_t * passwd, size_t passwdlen, const uint8_t * salt, size_t saltlen, uint64_t c, uint8_t * buf, size_t dkLen) { hmac_sha256_ctx PShctx, hctx; size_t i; uint8_t ivec[4]; uint8_t U[SHA256_DIGEST_LEN]; uint8_t T[SHA256_DIGEST_LEN]; uint64_t j; unsigned int k; size_t clen; /* Compute HMAC state after processing P and S. */ hmac_sha256_init(&PShctx, passwd, passwdlen); hmac_sha256_update(&PShctx, salt, saltlen); /* Iterate through the blocks. */ for (i = 0; i * 32 < dkLen; i++) { /* Generate INT(i + 1). */ be32enc(ivec, (uint32_t)(i + 1)); /* Compute U_1 = PRF(P, S || INT(i)). */ memcpy(&hctx, &PShctx, sizeof(hmac_sha256_ctx)); hmac_sha256_update(&hctx, ivec, 4); hmac_sha256_final(&hctx, U); /* T_i = U_1 ... */ memcpy(T, U, sizeof T); for (j = 2; j <= c; j++) { /* Compute U_j. */ hmac_sha256_init(&hctx, passwd, passwdlen); hmac_sha256_update(&hctx, U, 32); hmac_sha256_final(&hctx, U); /* ... xor U_j ... */ for (k = 0; k < sizeof T; k++) T[k] ^= U[k]; } /* Copy as many bytes as necessary into buf. */ clen = dkLen - i * 32; if (clen > 32) clen = 32; memcpy(&buf[i * 32], T, clen); } /* Clean PShctx, since we never called _final on it. */ memset(&PShctx, 0, sizeof(hmac_sha256_ctx)); } #endif digest_algorithm sha256_digest = { .name = "sha256", .contextlen = sizeof sha256_digest, .blocklen = SHA256_BLOCK_LEN, .digestlen = SHA256_DIGEST_LEN, .init = (digest_init_func)sha256_init, .update = (digest_update_func)sha256_update, .final = (digest_final_func)sha256_final, .complete = (digest_complete_func)sha256_complete, };