| /*- |
| * Copyright 2005,2007,2009 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 "scrypt_platform.h" |
| |
| #include <sys/types.h> |
| |
| #include <stdint.h> |
| #include <string.h> |
| |
| #include "sysendian.h" |
| |
| #include "sha256.h" |
| |
| /* |
| * Encode a length len/4 vector of (uint32_t) into a length len vector of |
| * (unsigned char) in big-endian form. Assumes len is a multiple of 4. |
| */ |
| static void |
| be32enc_vect(unsigned char *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 (unsigned char) into a length |
| * len/4 vector of (uint32_t). Assumes len is a multiple of 4. |
| */ |
| static void |
| be32dec_vect(uint32_t *dst, const unsigned char *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 unsigned char 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 unsigned char 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) |
| { |
| unsigned char 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. |
| */ |
| be32enc_vect(len, ctx->count, 8); |
| |
| /* Add 1--64 bytes so that the resulting length is 56 mod 64 */ |
| r = (ctx->count[1] >> 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); |
| } |
| |
| /* SHA-256 initialization. Begins a SHA-256 operation. */ |
| void |
| SHA256_Init(SHA256_CTX * ctx) |
| { |
| |
| /* Zero bits processed so far */ |
| ctx->count[0] = ctx->count[1] = 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; |
| } |
| |
| /* Add bytes into the hash */ |
| void |
| SHA256_Update(SHA256_CTX * ctx, const void *in, size_t len) |
| { |
| uint32_t bitlen[2]; |
| uint32_t r; |
| const unsigned char *src = in; |
| |
| /* Number of bytes left in the buffer from previous updates */ |
| r = (ctx->count[1] >> 3) & 0x3f; |
| |
| /* Convert the length into a number of bits */ |
| bitlen[1] = ((uint32_t)len) << 3; |
| bitlen[0] = (uint32_t)(len >> 29); |
| |
| /* Update number of bits */ |
| if ((ctx->count[1] += bitlen[1]) < bitlen[1]) |
| ctx->count[0]++; |
| ctx->count[0] += bitlen[0]; |
| |
| /* 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); |
| } |
| |
| /* |
| * SHA-256 finalization. Pads the input data, exports the hash value, |
| * and clears the context state. |
| */ |
| void |
| SHA256_Final(unsigned char digest[32], SHA256_CTX * ctx) |
| { |
| |
| /* Add padding */ |
| SHA256_Pad(ctx); |
| |
| /* Write the hash */ |
| be32enc_vect(digest, ctx->state, 32); |
| |
| /* Clear the context state */ |
| memset((void *)ctx, 0, sizeof(*ctx)); |
| } |
| |
| /* Initialize an HMAC-SHA256 operation with the given key. */ |
| void |
| HMAC_SHA256_Init(HMAC_SHA256_CTX * ctx, const void * _K, size_t Klen) |
| { |
| unsigned char pad[64]; |
| unsigned char khash[32]; |
| const unsigned char * K = _K; |
| size_t i; |
| |
| /* If Klen > 64, the key is really SHA256(K). */ |
| if (Klen > 64) { |
| SHA256_Init(&ctx->ictx); |
| SHA256_Update(&ctx->ictx, K, Klen); |
| SHA256_Final(khash, &ctx->ictx); |
| K = khash; |
| Klen = 32; |
| } |
| |
| /* Inner SHA256 operation is SHA256(K xor [block of 0x36] || data). */ |
| SHA256_Init(&ctx->ictx); |
| memset(pad, 0x36, 64); |
| for (i = 0; i < Klen; i++) |
| pad[i] ^= K[i]; |
| SHA256_Update(&ctx->ictx, pad, 64); |
| |
| /* Outer SHA256 operation is SHA256(K xor [block of 0x5c] || hash). */ |
| SHA256_Init(&ctx->octx); |
| memset(pad, 0x5c, 64); |
| for (i = 0; i < Klen; i++) |
| pad[i] ^= K[i]; |
| SHA256_Update(&ctx->octx, pad, 64); |
| |
| /* Clean the stack. */ |
| memset(khash, 0, 32); |
| } |
| |
| /* Add bytes to the HMAC-SHA256 operation. */ |
| void |
| HMAC_SHA256_Update(HMAC_SHA256_CTX * ctx, const void *in, size_t len) |
| { |
| |
| /* Feed data to the inner SHA256 operation. */ |
| SHA256_Update(&ctx->ictx, in, len); |
| } |
| |
| /* Finish an HMAC-SHA256 operation. */ |
| void |
| HMAC_SHA256_Final(unsigned char digest[32], HMAC_SHA256_CTX * ctx) |
| { |
| unsigned char ihash[32]; |
| |
| /* Finish the inner SHA256 operation. */ |
| SHA256_Final(ihash, &ctx->ictx); |
| |
| /* Feed the inner hash to the outer SHA256 operation. */ |
| SHA256_Update(&ctx->octx, ihash, 32); |
| |
| /* Finish the outer SHA256 operation. */ |
| SHA256_Final(digest, &ctx->octx); |
| |
| /* Clean the stack. */ |
| memset(ihash, 0, 32); |
| } |
| |
| /** |
| * 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[32]; |
| uint8_t T[32]; |
| uint64_t j; |
| 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(U, &hctx); |
| |
| /* T_i = U_1 ... */ |
| memcpy(T, U, 32); |
| |
| for (j = 2; j <= c; j++) { |
| /* Compute U_j. */ |
| HMAC_SHA256_Init(&hctx, passwd, passwdlen); |
| HMAC_SHA256_Update(&hctx, U, 32); |
| HMAC_SHA256_Final(U, &hctx); |
| |
| /* ... xor U_j ... */ |
| for (k = 0; k < 32; 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)); |
| } |