1 /* 2 * written by Colin Plumb in 1993, no copyright is claimed. 3 * This code is in the public domain; do with it what you wish. 4 * 5 * Equivalent code is available from RSA Data Security, Inc. 6 * This code has been tested against that, and is equivalent, 7 * except that you don't need to include two pages of legalese 8 * with every copy. 9 * 10 * To compute the message digest of a chunk of bytes, declare an 11 * MD5Context structure, pass it to MD5Init, call MD5Update as 12 * needed on buffers full of bytes, and then call MD5Final, which 13 * will fill a supplied 16-byte array with the digest. 14 */ 15 16 #include <string.h> 17 18 #include "common/md5.h" 19 20 namespace google_breakpad { 21 22 #ifndef WORDS_BIGENDIAN 23 #define byteReverse(buf, len) /* Nothing */ 24 #else 25 /* 26 * Note: this code is harmless on little-endian machines. 27 */ 28 static void byteReverse(unsigned char *buf, unsigned longs) 29 { 30 u32 t; 31 do { 32 t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 | 33 ((unsigned) buf[1] << 8 | buf[0]); 34 *(u32 *) buf = t; 35 buf += 4; 36 } while (--longs); 37 } 38 #endif 39 40 static void MD5Transform(u32 buf[4], u32 const in[16]); 41 42 /* 43 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious 44 * initialization constants. 45 */ 46 void MD5Init(struct MD5Context *ctx) 47 { 48 ctx->buf[0] = 0x67452301; 49 ctx->buf[1] = 0xefcdab89; 50 ctx->buf[2] = 0x98badcfe; 51 ctx->buf[3] = 0x10325476; 52 53 ctx->bits[0] = 0; 54 ctx->bits[1] = 0; 55 } 56 57 /* 58 * Update context to reflect the concatenation of another buffer full 59 * of bytes. 60 */ 61 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, size_t len) 62 { 63 u32 t; 64 65 /* Update bitcount */ 66 67 t = ctx->bits[0]; 68 if ((ctx->bits[0] = t + ((u32) len << 3)) < t) 69 ctx->bits[1]++; /* Carry from low to high */ 70 ctx->bits[1] += len >> 29; 71 72 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */ 73 74 /* Handle any leading odd-sized chunks */ 75 76 if (t) { 77 unsigned char *p = (unsigned char *) ctx->in + t; 78 79 t = 64 - t; 80 if (len < t) { 81 memcpy(p, buf, len); 82 return; 83 } 84 memcpy(p, buf, t); 85 byteReverse(ctx->in, 16); 86 MD5Transform(ctx->buf, (u32 *) ctx->in); 87 buf += t; 88 len -= t; 89 } 90 /* Process data in 64-byte chunks */ 91 92 while (len >= 64) { 93 memcpy(ctx->in, buf, 64); 94 byteReverse(ctx->in, 16); 95 MD5Transform(ctx->buf, (u32 *) ctx->in); 96 buf += 64; 97 len -= 64; 98 } 99 100 /* Handle any remaining bytes of data. */ 101 102 memcpy(ctx->in, buf, len); 103 } 104 105 /* 106 * Final wrapup - pad to 64-byte boundary with the bit pattern 107 * 1 0* (64-bit count of bits processed, MSB-first) 108 */ 109 void MD5Final(unsigned char digest[16], struct MD5Context *ctx) 110 { 111 unsigned count; 112 unsigned char *p; 113 114 /* Compute number of bytes mod 64 */ 115 count = (ctx->bits[0] >> 3) & 0x3F; 116 117 /* Set the first char of padding to 0x80. This is safe since there is 118 always at least one byte free */ 119 p = ctx->in + count; 120 *p++ = 0x80; 121 122 /* Bytes of padding needed to make 64 bytes */ 123 count = 64 - 1 - count; 124 125 /* Pad out to 56 mod 64 */ 126 if (count < 8) { 127 /* Two lots of padding: Pad the first block to 64 bytes */ 128 memset(p, 0, count); 129 byteReverse(ctx->in, 16); 130 MD5Transform(ctx->buf, (u32 *) ctx->in); 131 132 /* Now fill the next block with 56 bytes */ 133 memset(ctx->in, 0, 56); 134 } else { 135 /* Pad block to 56 bytes */ 136 memset(p, 0, count - 8); 137 } 138 byteReverse(ctx->in, 14); 139 140 /* Append length in bits and transform */ 141 ((u32 *) ctx->in)[14] = ctx->bits[0]; 142 ((u32 *) ctx->in)[15] = ctx->bits[1]; 143 144 MD5Transform(ctx->buf, (u32 *) ctx->in); 145 byteReverse((unsigned char *) ctx->buf, 4); 146 memcpy(digest, ctx->buf, 16); 147 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */ 148 } 149 150 /* The four core functions - F1 is optimized somewhat */ 151 152 /* #define F1(x, y, z) (x & y | ~x & z) */ 153 #define F1(x, y, z) (z ^ (x & (y ^ z))) 154 #define F2(x, y, z) F1(z, x, y) 155 #define F3(x, y, z) (x ^ y ^ z) 156 #define F4(x, y, z) (y ^ (x | ~z)) 157 158 /* This is the central step in the MD5 algorithm. */ 159 #define MD5STEP(f, w, x, y, z, data, s) \ 160 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x ) 161 162 /* 163 * The core of the MD5 algorithm, this alters an existing MD5 hash to 164 * reflect the addition of 16 longwords of new data. MD5Update blocks 165 * the data and converts bytes into longwords for this routine. 166 */ 167 static void MD5Transform(u32 buf[4], u32 const in[16]) 168 { 169 u32 a, b, c, d; 170 171 a = buf[0]; 172 b = buf[1]; 173 c = buf[2]; 174 d = buf[3]; 175 176 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); 177 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); 178 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); 179 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); 180 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); 181 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); 182 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); 183 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); 184 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); 185 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); 186 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); 187 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); 188 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); 189 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); 190 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); 191 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); 192 193 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); 194 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); 195 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); 196 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); 197 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); 198 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); 199 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); 200 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); 201 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); 202 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); 203 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); 204 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); 205 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); 206 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); 207 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); 208 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); 209 210 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); 211 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); 212 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); 213 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); 214 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); 215 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); 216 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); 217 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); 218 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); 219 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); 220 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); 221 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); 222 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); 223 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); 224 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); 225 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); 226 227 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); 228 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); 229 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); 230 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); 231 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); 232 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); 233 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); 234 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); 235 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); 236 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); 237 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); 238 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); 239 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); 240 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); 241 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); 242 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); 243 244 buf[0] += a; 245 buf[1] += b; 246 buf[2] += c; 247 buf[3] += d; 248 } 249 250 } // namespace google_breakpad 251 252
