1/* $OpenBSD: md5.c,v 1.4 2014/12/28 10:04:35 tedu 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 <sys/param.h> 21#include <sys/systm.h> 22#include <crypto/md5.h> 23 24#define PUT_64BIT_LE(cp, value) do { \ 25 (cp)[7] = (value) >> 56; \ 26 (cp)[6] = (value) >> 48; \ 27 (cp)[5] = (value) >> 40; \ 28 (cp)[4] = (value) >> 32; \ 29 (cp)[3] = (value) >> 24; \ 30 (cp)[2] = (value) >> 16; \ 31 (cp)[1] = (value) >> 8; \ 32 (cp)[0] = (value); } while (0) 33 34#define PUT_32BIT_LE(cp, value) do { \ 35 (cp)[3] = (value) >> 24; \ 36 (cp)[2] = (value) >> 16; \ 37 (cp)[1] = (value) >> 8; \ 38 (cp)[0] = (value); } while (0) 39 40static u_int8_t PADDING[MD5_BLOCK_LENGTH] = { 41 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42 0, 0, 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 44}; 45 46/* 47 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious 48 * initialization constants. 49 */ 50void 51MD5Init(MD5_CTX *ctx) 52{ 53 ctx->count = 0; 54 ctx->state[0] = 0x67452301; 55 ctx->state[1] = 0xefcdab89; 56 ctx->state[2] = 0x98badcfe; 57 ctx->state[3] = 0x10325476; 58} 59 60/* 61 * Update context to reflect the concatenation of another buffer full 62 * of bytes. 63 */ 64void 65MD5Update(MD5_CTX *ctx, const void *inputptr, size_t len) 66{ 67 const uint8_t *input = inputptr; 68 size_t have, need; 69 70 /* Check how many bytes we already have and how many more we need. */ 71 have = (size_t)((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1)); 72 need = MD5_BLOCK_LENGTH - have; 73 74 /* Update bitcount */ 75 ctx->count += (u_int64_t)len << 3; 76 77 if (len >= need) { 78 if (have != 0) { 79 memcpy(ctx->buffer + have, input, need); 80 MD5Transform(ctx->state, ctx->buffer); 81 input += need; 82 len -= need; 83 have = 0; 84 } 85 86 /* Process data in MD5_BLOCK_LENGTH-byte chunks. */ 87 while (len >= MD5_BLOCK_LENGTH) { 88 MD5Transform(ctx->state, input); 89 input += MD5_BLOCK_LENGTH; 90 len -= MD5_BLOCK_LENGTH; 91 } 92 } 93 94 /* Handle any remaining bytes of data. */ 95 if (len != 0) 96 memcpy(ctx->buffer + have, input, len); 97} 98 99/* 100 * Final wrapup - pad to 64-byte boundary with the bit pattern 101 * 1 0* (64-bit count of bits processed, MSB-first) 102 */ 103void 104MD5Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5_CTX *ctx) 105{ 106 u_int8_t count[8]; 107 size_t padlen; 108 int i; 109 110 /* Convert count to 8 bytes in little endian order. */ 111 PUT_64BIT_LE(count, ctx->count); 112 113 /* Pad out to 56 mod 64. */ 114 padlen = MD5_BLOCK_LENGTH - 115 ((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1)); 116 if (padlen < 1 + 8) 117 padlen += MD5_BLOCK_LENGTH; 118 MD5Update(ctx, PADDING, padlen - 8); /* padlen - 8 <= 64 */ 119 MD5Update(ctx, count, 8); 120 121 for (i = 0; i < 4; i++) 122 PUT_32BIT_LE(digest + i * 4, ctx->state[i]); 123 explicit_bzero(ctx, sizeof(*ctx)); /* in case it's sensitive */ 124} 125 126 127/* The four core functions - F1 is optimized somewhat */ 128 129/* #define F1(x, y, z) (x & y | ~x & z) */ 130#define F1(x, y, z) (z ^ (x & (y ^ z))) 131#define F2(x, y, z) F1(z, x, y) 132#define F3(x, y, z) (x ^ y ^ z) 133#define F4(x, y, z) (y ^ (x | ~z)) 134 135/* This is the central step in the MD5 algorithm. */ 136#define MD5STEP(f, w, x, y, z, data, s) \ 137 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x ) 138 139/* 140 * The core of the MD5 algorithm, this alters an existing MD5 hash to 141 * reflect the addition of 16 longwords of new data. MD5Update blocks 142 * the data and converts bytes into longwords for this routine. 143 */ 144void 145MD5Transform(u_int32_t state[4], const u_int8_t block[MD5_BLOCK_LENGTH]) 146{ 147 u_int32_t a, b, c, d, in[MD5_BLOCK_LENGTH / 4]; 148 149#if BYTE_ORDER == LITTLE_ENDIAN 150 memcpy(in, block, sizeof(in)); 151#else 152 for (a = 0; a < MD5_BLOCK_LENGTH / 4; a++) { 153 in[a] = (u_int32_t)( 154 (u_int32_t)(block[a * 4 + 0]) | 155 (u_int32_t)(block[a * 4 + 1]) << 8 | 156 (u_int32_t)(block[a * 4 + 2]) << 16 | 157 (u_int32_t)(block[a * 4 + 3]) << 24); 158 } 159#endif 160 161 a = state[0]; 162 b = state[1]; 163 c = state[2]; 164 d = state[3]; 165 166 MD5STEP(F1, a, b, c, d, in[ 0] + 0xd76aa478, 7); 167 MD5STEP(F1, d, a, b, c, in[ 1] + 0xe8c7b756, 12); 168 MD5STEP(F1, c, d, a, b, in[ 2] + 0x242070db, 17); 169 MD5STEP(F1, b, c, d, a, in[ 3] + 0xc1bdceee, 22); 170 MD5STEP(F1, a, b, c, d, in[ 4] + 0xf57c0faf, 7); 171 MD5STEP(F1, d, a, b, c, in[ 5] + 0x4787c62a, 12); 172 MD5STEP(F1, c, d, a, b, in[ 6] + 0xa8304613, 17); 173 MD5STEP(F1, b, c, d, a, in[ 7] + 0xfd469501, 22); 174 MD5STEP(F1, a, b, c, d, in[ 8] + 0x698098d8, 7); 175 MD5STEP(F1, d, a, b, c, in[ 9] + 0x8b44f7af, 12); 176 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); 177 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); 178 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); 179 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); 180 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); 181 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); 182 183 MD5STEP(F2, a, b, c, d, in[ 1] + 0xf61e2562, 5); 184 MD5STEP(F2, d, a, b, c, in[ 6] + 0xc040b340, 9); 185 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); 186 MD5STEP(F2, b, c, d, a, in[ 0] + 0xe9b6c7aa, 20); 187 MD5STEP(F2, a, b, c, d, in[ 5] + 0xd62f105d, 5); 188 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); 189 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); 190 MD5STEP(F2, b, c, d, a, in[ 4] + 0xe7d3fbc8, 20); 191 MD5STEP(F2, a, b, c, d, in[ 9] + 0x21e1cde6, 5); 192 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); 193 MD5STEP(F2, c, d, a, b, in[ 3] + 0xf4d50d87, 14); 194 MD5STEP(F2, b, c, d, a, in[ 8] + 0x455a14ed, 20); 195 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); 196 MD5STEP(F2, d, a, b, c, in[ 2] + 0xfcefa3f8, 9); 197 MD5STEP(F2, c, d, a, b, in[ 7] + 0x676f02d9, 14); 198 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); 199 200 MD5STEP(F3, a, b, c, d, in[ 5] + 0xfffa3942, 4); 201 MD5STEP(F3, d, a, b, c, in[ 8] + 0x8771f681, 11); 202 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); 203 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); 204 MD5STEP(F3, a, b, c, d, in[ 1] + 0xa4beea44, 4); 205 MD5STEP(F3, d, a, b, c, in[ 4] + 0x4bdecfa9, 11); 206 MD5STEP(F3, c, d, a, b, in[ 7] + 0xf6bb4b60, 16); 207 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); 208 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); 209 MD5STEP(F3, d, a, b, c, in[ 0] + 0xeaa127fa, 11); 210 MD5STEP(F3, c, d, a, b, in[ 3] + 0xd4ef3085, 16); 211 MD5STEP(F3, b, c, d, a, in[ 6] + 0x04881d05, 23); 212 MD5STEP(F3, a, b, c, d, in[ 9] + 0xd9d4d039, 4); 213 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); 214 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); 215 MD5STEP(F3, b, c, d, a, in[2 ] + 0xc4ac5665, 23); 216 217 MD5STEP(F4, a, b, c, d, in[ 0] + 0xf4292244, 6); 218 MD5STEP(F4, d, a, b, c, in[7 ] + 0x432aff97, 10); 219 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); 220 MD5STEP(F4, b, c, d, a, in[5 ] + 0xfc93a039, 21); 221 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); 222 MD5STEP(F4, d, a, b, c, in[3 ] + 0x8f0ccc92, 10); 223 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); 224 MD5STEP(F4, b, c, d, a, in[1 ] + 0x85845dd1, 21); 225 MD5STEP(F4, a, b, c, d, in[8 ] + 0x6fa87e4f, 6); 226 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); 227 MD5STEP(F4, c, d, a, b, in[6 ] + 0xa3014314, 15); 228 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); 229 MD5STEP(F4, a, b, c, d, in[4 ] + 0xf7537e82, 6); 230 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); 231 MD5STEP(F4, c, d, a, b, in[2 ] + 0x2ad7d2bb, 15); 232 MD5STEP(F4, b, c, d, a, in[9 ] + 0xeb86d391, 21); 233 234 state[0] += a; 235 state[1] += b; 236 state[2] += c; 237 state[3] += d; 238} 239