1 /* 2 * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm 3 * 4 * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All 5 * rights reserved. 6 * 7 * License to copy and use this software is granted provided that it 8 * is identified as the "RSA Data Security, Inc. MD5 Message-Digest 9 * Algorithm" in all material mentioning or referencing this software 10 * or this function. 11 * 12 * License is also granted to make and use derivative works provided 13 * that such works are identified as "derived from the RSA Data 14 * Security, Inc. MD5 Message-Digest Algorithm" in all material 15 * mentioning or referencing the derived work. 16 * 17 * RSA Data Security, Inc. makes no representations concerning either 18 * the merchantability of this software or the suitability of this 19 * software for any particular purpose. It is provided "as is" 20 * without express or implied warranty of any kind. 21 * 22 * These notices must be retained in any copies of any part of this 23 * documentation and/or software. 24 * 25 * This code is the same as the code published by RSA Inc. It has been 26 * edited for clarity and style only. 27 */ 28 29 #include <string.h> 30 #include <endian.h> 31 #include <md5.h> 32 33 static void MD5Transform(uint32_t[4], const unsigned char[64]); 34 35 #define Encode memcpy 36 #define Decode memcpy 37 38 static unsigned char PADDING[64] = { 39 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 40 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 41 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 42 }; 43 44 /* F, G, H and I are basic MD5 functions. */ 45 #define F(x, y, z) (((x) & (y)) | ((~x) & (z))) 46 #define G(x, y, z) (((x) & (z)) | ((y) & (~z))) 47 #define H(x, y, z) ((x) ^ (y) ^ (z)) 48 #define I(x, y, z) ((y) ^ ((x) | (~z))) 49 50 /* ROTATE_LEFT rotates x left n bits. */ 51 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n)))) 52 53 /* 54 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4. 55 * Rotation is separate from addition to prevent recomputation. 56 */ 57 #define FF(a, b, c, d, x, s, ac) { \ 58 (a) += F ((b), (c), (d)) + (x) + (uint32_t)(ac); \ 59 (a) = ROTATE_LEFT ((a), (s)); \ 60 (a) += (b); \ 61 } 62 #define GG(a, b, c, d, x, s, ac) { \ 63 (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \ 64 (a) = ROTATE_LEFT ((a), (s)); \ 65 (a) += (b); \ 66 } 67 #define HH(a, b, c, d, x, s, ac) { \ 68 (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \ 69 (a) = ROTATE_LEFT ((a), (s)); \ 70 (a) += (b); \ 71 } 72 #define II(a, b, c, d, x, s, ac) { \ 73 (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \ 74 (a) = ROTATE_LEFT ((a), (s)); \ 75 (a) += (b); \ 76 } 77 78 /* MD5 initialization. Begins an MD5 operation, writing a new context. */ 79 80 void MD5Init(MD5_CTX * context) 81 { 82 context->count[0] = context->count[1] = 0; 83 84 /* Load magic initialization constants. */ 85 context->state[0] = 0x67452301; 86 context->state[1] = 0xefcdab89; 87 context->state[2] = 0x98badcfe; 88 context->state[3] = 0x10325476; 89 } 90 91 /* 92 * MD5 block update operation. Continues an MD5 message-digest 93 * operation, processing another message block, and updating the 94 * context. 95 */ 96 97 void MD5Update(MD5_CTX * context, const void *in, size_t inputLen) 98 { 99 unsigned int i, idx, partLen; 100 const unsigned char *input = in; 101 102 /* Compute number of bytes mod 64 */ 103 idx = (unsigned int)((context->count[0] >> 3) & 0x3F); 104 105 /* Update number of bits */ 106 if ((context->count[0] += ((uint32_t) inputLen << 3)) 107 < ((uint32_t) inputLen << 3)) 108 context->count[1]++; 109 context->count[1] += ((uint32_t) inputLen >> 29); 110 111 partLen = 64 - idx; 112 113 /* Transform as many times as possible. */ 114 if (inputLen >= partLen) { 115 memcpy((void *)&context->buffer[idx], (const void *)input, partLen); 116 MD5Transform(context->state, context->buffer); 117 118 for (i = partLen; i + 63 < inputLen; i += 64) 119 MD5Transform(context->state, &input[i]); 120 121 idx = 0; 122 } else 123 i = 0; 124 125 /* Buffer remaining input */ 126 memcpy((void *)&context->buffer[idx], (const void *)&input[i], 127 inputLen - i); 128 } 129 130 /* 131 * MD5 padding. Adds padding followed by original length. 132 */ 133 134 static void MD5Pad(MD5_CTX * context) 135 { 136 unsigned char bits[8]; 137 unsigned int idx, padLen; 138 139 /* Save number of bits */ 140 Encode(bits, context->count, 8); 141 142 /* Pad out to 56 mod 64. */ 143 idx = (unsigned int)((context->count[0] >> 3) & 0x3f); 144 padLen = (idx < 56) ? (56 - idx) : (120 - idx); 145 MD5Update(context, PADDING, padLen); 146 147 /* Append length (before padding) */ 148 MD5Update(context, bits, 8); 149 } 150 151 /* 152 * MD5 finalization. Ends an MD5 message-digest operation, writing the 153 * the message digest and zeroizing the context. 154 */ 155 156 void MD5Final(unsigned char digest[16], MD5_CTX * context) 157 { 158 /* Do padding. */ 159 MD5Pad(context); 160 161 /* Store state in digest */ 162 Encode(digest, context->state, 16); 163 164 /* Zeroize sensitive information. */ 165 memset((void *)context, 0, sizeof(*context)); 166 } 167 168 /* MD5 basic transformation. Transforms state based on block. */ 169 170 static void MD5Transform(state, block) 171 uint32_t state[4]; 172 const unsigned char block[64]; 173 { 174 uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16]; 175 176 Decode(x, block, 64); 177 178 /* Round 1 */ 179 #define S11 7 180 #define S12 12 181 #define S13 17 182 #define S14 22 183 FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */ 184 FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */ 185 FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */ 186 FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */ 187 FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */ 188 FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */ 189 FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */ 190 FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */ 191 FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */ 192 FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */ 193 FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */ 194 FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */ 195 FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */ 196 FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */ 197 FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */ 198 FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */ 199 200 /* Round 2 */ 201 #define S21 5 202 #define S22 9 203 #define S23 14 204 #define S24 20 205 GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */ 206 GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */ 207 GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */ 208 GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */ 209 GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */ 210 GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */ 211 GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */ 212 GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */ 213 GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */ 214 GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */ 215 GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */ 216 GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */ 217 GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */ 218 GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */ 219 GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */ 220 GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */ 221 222 /* Round 3 */ 223 #define S31 4 224 #define S32 11 225 #define S33 16 226 #define S34 23 227 HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */ 228 HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */ 229 HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */ 230 HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */ 231 HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */ 232 HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */ 233 HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */ 234 HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */ 235 HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */ 236 HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */ 237 HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */ 238 HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */ 239 HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */ 240 HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */ 241 HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */ 242 HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */ 243 244 /* Round 4 */ 245 #define S41 6 246 #define S42 10 247 #define S43 15 248 #define S44 21 249 II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */ 250 II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */ 251 II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */ 252 II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */ 253 II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */ 254 II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */ 255 II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */ 256 II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */ 257 II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */ 258 II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */ 259 II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */ 260 II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */ 261 II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */ 262 II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */ 263 II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */ 264 II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */ 265 266 state[0] += a; 267 state[1] += b; 268 state[2] += c; 269 state[3] += d; 270 271 /* Zeroize sensitive information. */ 272 memset((void *)x, 0, sizeof(x)); 273 } 274
