1 /*- 2 * Copyright 2005 Colin Percival 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/endian.h> 31 #include <sys/types.h> 32 33 #ifdef _KERNEL 34 #include <sys/systm.h> 35 #else 36 #include <string.h> 37 #endif 38 39 #include "sha256.h" 40 41 #if BYTE_ORDER == BIG_ENDIAN 42 43 /* Copy a vector of big-endian uint32_t into a vector of bytes */ 44 #define be32enc_vect(dst, src, len) \ 45 memcpy((void *)dst, (const void *)src, (size_t)len) 46 47 /* Copy a vector of bytes into a vector of big-endian uint32_t */ 48 #define be32dec_vect(dst, src, len) \ 49 memcpy((void *)dst, (const void *)src, (size_t)len) 50 51 #else /* BYTE_ORDER != BIG_ENDIAN */ 52 53 /* 54 * Encode a length len/4 vector of (uint32_t) into a length len vector of 55 * (unsigned char) in big-endian form. Assumes len is a multiple of 4. 56 */ 57 static void 58 be32enc_vect(unsigned char *dst, const uint32_t *src, size_t len) 59 { 60 size_t i; 61 62 for (i = 0; i < len / 4; i++) 63 be32enc(dst + i * 4, src[i]); 64 } 65 66 /* 67 * Decode a big-endian length len vector of (unsigned char) into a length 68 * len/4 vector of (uint32_t). Assumes len is a multiple of 4. 69 */ 70 static void 71 be32dec_vect(uint32_t *dst, const unsigned char *src, size_t len) 72 { 73 size_t i; 74 75 for (i = 0; i < len / 4; i++) 76 dst[i] = be32dec(src + i * 4); 77 } 78 79 #endif /* BYTE_ORDER != BIG_ENDIAN */ 80 81 /* Elementary functions used by SHA256 */ 82 #define Ch(x, y, z) ((x & (y ^ z)) ^ z) 83 #define Maj(x, y, z) ((x & (y | z)) | (y & z)) 84 #define SHR(x, n) (x >> n) 85 #define ROTR(x, n) ((x >> n) | (x << (32 - n))) 86 #define S0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22)) 87 #define S1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25)) 88 #define s0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3)) 89 #define s1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10)) 90 91 /* SHA256 round function */ 92 #define RND(a, b, c, d, e, f, g, h, k) \ 93 t0 = h + S1(e) + Ch(e, f, g) + k; \ 94 t1 = S0(a) + Maj(a, b, c); \ 95 d += t0; \ 96 h = t0 + t1; 97 98 /* Adjusted round function for rotating state */ 99 #define RNDr(S, W, i, k) \ 100 RND(S[(64 - i) % 8], S[(65 - i) % 8], \ 101 S[(66 - i) % 8], S[(67 - i) % 8], \ 102 S[(68 - i) % 8], S[(69 - i) % 8], \ 103 S[(70 - i) % 8], S[(71 - i) % 8], \ 104 W[i] + k) 105 106 /* 107 * SHA256 block compression function. The 256-bit state is transformed via 108 * the 512-bit input block to produce a new state. 109 */ 110 static void 111 SHA256_Transform(uint32_t * state, const unsigned char block[64]) 112 { 113 uint32_t W[64]; 114 uint32_t S[8]; 115 uint32_t t0, t1; 116 int i; 117 118 /* 1. Prepare message schedule W. */ 119 be32dec_vect(W, block, 64); 120 for (i = 16; i < 64; i++) 121 W[i] = s1(W[i - 2]) + W[i - 7] + s0(W[i - 15]) + W[i - 16]; 122 123 /* 2. Initialize working variables. */ 124 memcpy(S, state, 32); 125 126 /* 3. Mix. */ 127 RNDr(S, W, 0, 0x428a2f98); 128 RNDr(S, W, 1, 0x71374491); 129 RNDr(S, W, 2, 0xb5c0fbcf); 130 RNDr(S, W, 3, 0xe9b5dba5); 131 RNDr(S, W, 4, 0x3956c25b); 132 RNDr(S, W, 5, 0x59f111f1); 133 RNDr(S, W, 6, 0x923f82a4); 134 RNDr(S, W, 7, 0xab1c5ed5); 135 RNDr(S, W, 8, 0xd807aa98); 136 RNDr(S, W, 9, 0x12835b01); 137 RNDr(S, W, 10, 0x243185be); 138 RNDr(S, W, 11, 0x550c7dc3); 139 RNDr(S, W, 12, 0x72be5d74); 140 RNDr(S, W, 13, 0x80deb1fe); 141 RNDr(S, W, 14, 0x9bdc06a7); 142 RNDr(S, W, 15, 0xc19bf174); 143 RNDr(S, W, 16, 0xe49b69c1); 144 RNDr(S, W, 17, 0xefbe4786); 145 RNDr(S, W, 18, 0x0fc19dc6); 146 RNDr(S, W, 19, 0x240ca1cc); 147 RNDr(S, W, 20, 0x2de92c6f); 148 RNDr(S, W, 21, 0x4a7484aa); 149 RNDr(S, W, 22, 0x5cb0a9dc); 150 RNDr(S, W, 23, 0x76f988da); 151 RNDr(S, W, 24, 0x983e5152); 152 RNDr(S, W, 25, 0xa831c66d); 153 RNDr(S, W, 26, 0xb00327c8); 154 RNDr(S, W, 27, 0xbf597fc7); 155 RNDr(S, W, 28, 0xc6e00bf3); 156 RNDr(S, W, 29, 0xd5a79147); 157 RNDr(S, W, 30, 0x06ca6351); 158 RNDr(S, W, 31, 0x14292967); 159 RNDr(S, W, 32, 0x27b70a85); 160 RNDr(S, W, 33, 0x2e1b2138); 161 RNDr(S, W, 34, 0x4d2c6dfc); 162 RNDr(S, W, 35, 0x53380d13); 163 RNDr(S, W, 36, 0x650a7354); 164 RNDr(S, W, 37, 0x766a0abb); 165 RNDr(S, W, 38, 0x81c2c92e); 166 RNDr(S, W, 39, 0x92722c85); 167 RNDr(S, W, 40, 0xa2bfe8a1); 168 RNDr(S, W, 41, 0xa81a664b); 169 RNDr(S, W, 42, 0xc24b8b70); 170 RNDr(S, W, 43, 0xc76c51a3); 171 RNDr(S, W, 44, 0xd192e819); 172 RNDr(S, W, 45, 0xd6990624); 173 RNDr(S, W, 46, 0xf40e3585); 174 RNDr(S, W, 47, 0x106aa070); 175 RNDr(S, W, 48, 0x19a4c116); 176 RNDr(S, W, 49, 0x1e376c08); 177 RNDr(S, W, 50, 0x2748774c); 178 RNDr(S, W, 51, 0x34b0bcb5); 179 RNDr(S, W, 52, 0x391c0cb3); 180 RNDr(S, W, 53, 0x4ed8aa4a); 181 RNDr(S, W, 54, 0x5b9cca4f); 182 RNDr(S, W, 55, 0x682e6ff3); 183 RNDr(S, W, 56, 0x748f82ee); 184 RNDr(S, W, 57, 0x78a5636f); 185 RNDr(S, W, 58, 0x84c87814); 186 RNDr(S, W, 59, 0x8cc70208); 187 RNDr(S, W, 60, 0x90befffa); 188 RNDr(S, W, 61, 0xa4506ceb); 189 RNDr(S, W, 62, 0xbef9a3f7); 190 RNDr(S, W, 63, 0xc67178f2); 191 192 /* 4. Mix local working variables into global state */ 193 for (i = 0; i < 8; i++) 194 state[i] += S[i]; 195 } 196 197 static unsigned char PAD[64] = { 198 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 199 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 200 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 201 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 202 }; 203 204 /* Add padding and terminating bit-count. */ 205 static void 206 SHA256_Pad(SHA256_CTX * ctx) 207 { 208 unsigned char len[8]; 209 uint32_t r, plen; 210 211 /* 212 * Convert length to a vector of bytes -- we do this now rather 213 * than later because the length will change after we pad. 214 */ 215 be64enc(len, ctx->count); 216 217 /* Add 1--64 bytes so that the resulting length is 56 mod 64 */ 218 r = (ctx->count >> 3) & 0x3f; 219 plen = (r < 56) ? (56 - r) : (120 - r); 220 SHA256_Update(ctx, PAD, (size_t)plen); 221 222 /* Add the terminating bit-count */ 223 SHA256_Update(ctx, len, 8); 224 } 225 226 /* SHA-256 initialization. Begins a SHA-256 operation. */ 227 void 228 SHA256_Init(SHA256_CTX * ctx) 229 { 230 231 /* Zero bits processed so far */ 232 ctx->count = 0; 233 234 /* Magic initialization constants */ 235 ctx->state[0] = 0x6A09E667; 236 ctx->state[1] = 0xBB67AE85; 237 ctx->state[2] = 0x3C6EF372; 238 ctx->state[3] = 0xA54FF53A; 239 ctx->state[4] = 0x510E527F; 240 ctx->state[5] = 0x9B05688C; 241 ctx->state[6] = 0x1F83D9AB; 242 ctx->state[7] = 0x5BE0CD19; 243 } 244 245 /* Add bytes into the hash */ 246 void 247 SHA256_Update(SHA256_CTX * ctx, const void *in, size_t len) 248 { 249 uint64_t bitlen; 250 uint32_t r; 251 const unsigned char *src = in; 252 253 /* Number of bytes left in the buffer from previous updates */ 254 r = (ctx->count >> 3) & 0x3f; 255 256 /* Convert the length into a number of bits */ 257 bitlen = len << 3; 258 259 /* Update number of bits */ 260 ctx->count += bitlen; 261 262 /* Handle the case where we don't need to perform any transforms */ 263 if (len < 64 - r) { 264 memcpy(&ctx->buf[r], src, len); 265 return; 266 } 267 268 /* Finish the current block */ 269 memcpy(&ctx->buf[r], src, 64 - r); 270 SHA256_Transform(ctx->state, ctx->buf); 271 src += 64 - r; 272 len -= 64 - r; 273 274 /* Perform complete blocks */ 275 while (len >= 64) { 276 SHA256_Transform(ctx->state, src); 277 src += 64; 278 len -= 64; 279 } 280 281 /* Copy left over data into buffer */ 282 memcpy(ctx->buf, src, len); 283 } 284 285 /* 286 * SHA-256 finalization. Pads the input data, exports the hash value, 287 * and clears the context state. 288 */ 289 void 290 SHA256_Final(unsigned char digest[32], SHA256_CTX * ctx) 291 { 292 293 /* Add padding */ 294 SHA256_Pad(ctx); 295 296 /* Write the hash */ 297 be32enc_vect(digest, ctx->state, 32); 298 299 /* Clear the context state */ 300 memset((void *)ctx, 0, sizeof(*ctx)); 301 } 302