md5.c (7987B)
1 /* $OpenBSD: md5.c,v 1.2 2011/01/11 15:42:05 deraadt Exp $ */ 2 3 /* 4 * This code implements the MD5 message-digest algorithm. 5 * The algorithm is due to Ron Rivest. This code was 6 * written by Colin Plumb in 1993, no copyright is claimed. 7 * This code is in the public domain; do with it what you wish. 8 * 9 * Equivalent code is available from RSA Data Security, Inc. 10 * This code has been tested against that, and is equivalent, 11 * except that you don't need to include two pages of legalese 12 * with every copy. 13 * 14 * To compute the message digest of a chunk of bytes, declare an 15 * MD5Context structure, pass it to MD5Init, call MD5Update as 16 * needed on buffers full of bytes, and then call MD5Final, which 17 * will fill a supplied 16-byte array with the digest. 18 */ 19 20 #include <stdio.h> 21 #include <strings.h> 22 #include <stdint.h> 23 24 #include "md5.h" 25 26 #define PUT_64BIT_LE(cp, value) do { \ 27 (cp)[7] = (value) >> 56; \ 28 (cp)[6] = (value) >> 48; \ 29 (cp)[5] = (value) >> 40; \ 30 (cp)[4] = (value) >> 32; \ 31 (cp)[3] = (value) >> 24; \ 32 (cp)[2] = (value) >> 16; \ 33 (cp)[1] = (value) >> 8; \ 34 (cp)[0] = (value); } while (0) 35 36 #define PUT_32BIT_LE(cp, value) do { \ 37 (cp)[3] = (value) >> 24; \ 38 (cp)[2] = (value) >> 16; \ 39 (cp)[1] = (value) >> 8; \ 40 (cp)[0] = (value); } while (0) 41 42 static uint8_t PADDING[MD5_BLOCK_LENGTH] = { 43 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 44 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 45 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 46 }; 47 48 /* 49 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious 50 * initialization constants. 51 */ 52 void 53 MD5Init(MD5_CTX *ctx) 54 { 55 ctx->count = 0; 56 ctx->state[0] = 0x67452301; 57 ctx->state[1] = 0xefcdab89; 58 ctx->state[2] = 0x98badcfe; 59 ctx->state[3] = 0x10325476; 60 } 61 62 /* 63 * Update context to reflect the concatenation of another buffer full 64 * of bytes. 65 */ 66 void 67 MD5Update(MD5_CTX *ctx, const unsigned char *input, size_t len) 68 { 69 size_t have, need; 70 71 /* Check how many bytes we already have and how many more we need. */ 72 have = (size_t)((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1)); 73 need = MD5_BLOCK_LENGTH - have; 74 75 /* Update bitcount */ 76 ctx->count += (uint64_t)len << 3; 77 78 if (len >= need) { 79 if (have != 0) { 80 bcopy(input, ctx->buffer + have, need); 81 MD5Transform(ctx->state, ctx->buffer); 82 input += need; 83 len -= need; 84 have = 0; 85 } 86 87 /* Process data in MD5_BLOCK_LENGTH-byte chunks. */ 88 while (len >= MD5_BLOCK_LENGTH) { 89 MD5Transform(ctx->state, input); 90 input += MD5_BLOCK_LENGTH; 91 len -= MD5_BLOCK_LENGTH; 92 } 93 } 94 95 /* Handle any remaining bytes of data. */ 96 if (len != 0) 97 bcopy(input, ctx->buffer + have, len); 98 } 99 100 /* explicit_bzero - don't let the compiler optimize away bzero */ 101 static void 102 explicit_bzero(void *p, size_t n) 103 { 104 bzero(p, n); 105 } 106 107 /* 108 * Final wrapup - pad to 64-byte boundary with the bit pattern 109 * 1 0* (64-bit count of bits processed, MSB-first) 110 */ 111 void 112 MD5Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5_CTX *ctx) 113 { 114 uint8_t count[8]; 115 size_t padlen; 116 int i; 117 118 /* Convert count to 8 bytes in little endian order. */ 119 PUT_64BIT_LE(count, ctx->count); 120 121 /* Pad out to 56 mod 64. */ 122 padlen = MD5_BLOCK_LENGTH - 123 ((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1)); 124 if (padlen < 1 + 8) 125 padlen += MD5_BLOCK_LENGTH; 126 MD5Update(ctx, PADDING, padlen - 8); /* padlen - 8 <= 64 */ 127 MD5Update(ctx, count, 8); 128 129 if (digest != NULL) { 130 for (i = 0; i < 4; i++) 131 PUT_32BIT_LE(digest + i * 4, ctx->state[i]); 132 } 133 explicit_bzero(ctx, sizeof(*ctx)); /* in case it's sensitive */ 134 } 135 136 /* The four core functions - F1 is optimized somewhat */ 137 138 /* #define F1(x, y, z) (x & y | ~x & z) */ 139 #define F1(x, y, z) (z ^ (x & (y ^ z))) 140 #define F2(x, y, z) F1(z, x, y) 141 #define F3(x, y, z) (x ^ y ^ z) 142 #define F4(x, y, z) (y ^ (x | ~z)) 143 144 /* This is the central step in the MD5 algorithm. */ 145 #define MD5STEP(f, w, x, y, z, data, s) \ 146 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x ) 147 148 /* 149 * The core of the MD5 algorithm, this alters an existing MD5 hash to 150 * reflect the addition of 16 longwords of new data. MD5Update blocks 151 * the data and converts bytes into longwords for this routine. 152 */ 153 void 154 MD5Transform(uint32_t state[4], const uint8_t block[MD5_BLOCK_LENGTH]) 155 { 156 uint32_t a, b, c, d, in[MD5_BLOCK_LENGTH / 4]; 157 158 #if BYTE_ORDER == LITTLE_ENDIAN 159 bcopy(block, in, sizeof(in)); 160 #else 161 for (a = 0; a < MD5_BLOCK_LENGTH / 4; a++) { 162 in[a] = (uint32_t)( 163 (uint32_t)(block[a * 4 + 0]) | 164 (uint32_t)(block[a * 4 + 1]) << 8 | 165 (uint32_t)(block[a * 4 + 2]) << 16 | 166 (uint32_t)(block[a * 4 + 3]) << 24); 167 } 168 #endif 169 170 a = state[0]; 171 b = state[1]; 172 c = state[2]; 173 d = state[3]; 174 175 MD5STEP(F1, a, b, c, d, in[ 0] + 0xd76aa478, 7); 176 MD5STEP(F1, d, a, b, c, in[ 1] + 0xe8c7b756, 12); 177 MD5STEP(F1, c, d, a, b, in[ 2] + 0x242070db, 17); 178 MD5STEP(F1, b, c, d, a, in[ 3] + 0xc1bdceee, 22); 179 MD5STEP(F1, a, b, c, d, in[ 4] + 0xf57c0faf, 7); 180 MD5STEP(F1, d, a, b, c, in[ 5] + 0x4787c62a, 12); 181 MD5STEP(F1, c, d, a, b, in[ 6] + 0xa8304613, 17); 182 MD5STEP(F1, b, c, d, a, in[ 7] + 0xfd469501, 22); 183 MD5STEP(F1, a, b, c, d, in[ 8] + 0x698098d8, 7); 184 MD5STEP(F1, d, a, b, c, in[ 9] + 0x8b44f7af, 12); 185 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); 186 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); 187 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); 188 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); 189 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); 190 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); 191 192 MD5STEP(F2, a, b, c, d, in[ 1] + 0xf61e2562, 5); 193 MD5STEP(F2, d, a, b, c, in[ 6] + 0xc040b340, 9); 194 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); 195 MD5STEP(F2, b, c, d, a, in[ 0] + 0xe9b6c7aa, 20); 196 MD5STEP(F2, a, b, c, d, in[ 5] + 0xd62f105d, 5); 197 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); 198 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); 199 MD5STEP(F2, b, c, d, a, in[ 4] + 0xe7d3fbc8, 20); 200 MD5STEP(F2, a, b, c, d, in[ 9] + 0x21e1cde6, 5); 201 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); 202 MD5STEP(F2, c, d, a, b, in[ 3] + 0xf4d50d87, 14); 203 MD5STEP(F2, b, c, d, a, in[ 8] + 0x455a14ed, 20); 204 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); 205 MD5STEP(F2, d, a, b, c, in[ 2] + 0xfcefa3f8, 9); 206 MD5STEP(F2, c, d, a, b, in[ 7] + 0x676f02d9, 14); 207 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); 208 209 MD5STEP(F3, a, b, c, d, in[ 5] + 0xfffa3942, 4); 210 MD5STEP(F3, d, a, b, c, in[ 8] + 0x8771f681, 11); 211 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); 212 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); 213 MD5STEP(F3, a, b, c, d, in[ 1] + 0xa4beea44, 4); 214 MD5STEP(F3, d, a, b, c, in[ 4] + 0x4bdecfa9, 11); 215 MD5STEP(F3, c, d, a, b, in[ 7] + 0xf6bb4b60, 16); 216 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); 217 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); 218 MD5STEP(F3, d, a, b, c, in[ 0] + 0xeaa127fa, 11); 219 MD5STEP(F3, c, d, a, b, in[ 3] + 0xd4ef3085, 16); 220 MD5STEP(F3, b, c, d, a, in[ 6] + 0x04881d05, 23); 221 MD5STEP(F3, a, b, c, d, in[ 9] + 0xd9d4d039, 4); 222 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); 223 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); 224 MD5STEP(F3, b, c, d, a, in[2 ] + 0xc4ac5665, 23); 225 226 MD5STEP(F4, a, b, c, d, in[ 0] + 0xf4292244, 6); 227 MD5STEP(F4, d, a, b, c, in[7 ] + 0x432aff97, 10); 228 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); 229 MD5STEP(F4, b, c, d, a, in[5 ] + 0xfc93a039, 21); 230 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); 231 MD5STEP(F4, d, a, b, c, in[3 ] + 0x8f0ccc92, 10); 232 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); 233 MD5STEP(F4, b, c, d, a, in[1 ] + 0x85845dd1, 21); 234 MD5STEP(F4, a, b, c, d, in[8 ] + 0x6fa87e4f, 6); 235 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); 236 MD5STEP(F4, c, d, a, b, in[6 ] + 0xa3014314, 15); 237 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); 238 MD5STEP(F4, a, b, c, d, in[4 ] + 0xf7537e82, 6); 239 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); 240 MD5STEP(F4, c, d, a, b, in[2 ] + 0x2ad7d2bb, 15); 241 MD5STEP(F4, b, c, d, a, in[9 ] + 0xeb86d391, 21); 242 243 state[0] += a; 244 state[1] += b; 245 state[2] += c; 246 state[3] += d; 247 }