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