| 1 | /* |
| 2 | * Copyright (c) 2007, Cameron Rich |
| 3 | * |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions are met: |
| 8 | * |
| 9 | * * Redistributions of source code must retain the above copyright notice, |
| 10 | * this list of conditions and the following disclaimer. |
| 11 | * * Redistributions in binary form must reproduce the above copyright notice, |
| 12 | * this list of conditions and the following disclaimer in the documentation |
| 13 | * and/or other materials provided with the distribution. |
| 14 | * * Neither the name of the axTLS project nor the names of its contributors |
| 15 | * may be used to endorse or promote products derived from this software |
| 16 | * without specific prior written permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| 22 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 23 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 24 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 25 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 26 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 27 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 28 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | */ |
| 30 | |
| 31 | /** |
| 32 | * This file implements the MD5 algorithm as defined in RFC1321 |
| 33 | */ |
| 34 | |
| 35 | #include <string.h> |
| 36 | #include "os_port.h" |
| 37 | #include "crypto.h" |
| 38 | |
| 39 | /* Constants for MD5Transform routine. |
| 40 | */ |
| 41 | #define S11 7 |
| 42 | #define S12 12 |
| 43 | #define S13 17 |
| 44 | #define S14 22 |
| 45 | #define S21 5 |
| 46 | #define S22 9 |
| 47 | #define S23 14 |
| 48 | #define S24 20 |
| 49 | #define S31 4 |
| 50 | #define S32 11 |
| 51 | #define S33 16 |
| 52 | #define S34 23 |
| 53 | #define S41 6 |
| 54 | #define S42 10 |
| 55 | #define S43 15 |
| 56 | #define S44 21 |
| 57 | |
| 58 | /* ----- static functions ----- */ |
| 59 | static void MD5Transform(uint32_t state[4], const uint8_t block[64]); |
| 60 | static void Encode(uint8_t *output, uint32_t *input, uint32_t len); |
| 61 | static void Decode(uint32_t *output, const uint8_t *input, uint32_t len); |
| 62 | |
| 63 | static const uint8_t PADDING[64] = |
| 64 | { |
| 65 | 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 66 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 67 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 |
| 68 | }; |
| 69 | |
| 70 | /* F, G, H and I are basic MD5 functions. |
| 71 | */ |
| 72 | #define F(x, y, z) (((x) & (y)) | ((~x) & (z))) |
| 73 | #define G(x, y, z) (((x) & (z)) | ((y) & (~z))) |
| 74 | #define H(x, y, z) ((x) ^ (y) ^ (z)) |
| 75 | #define I(x, y, z) ((y) ^ ((x) | (~z))) |
| 76 | |
| 77 | /* ROTATE_LEFT rotates x left n bits. */ |
| 78 | #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n)))) |
| 79 | |
| 80 | /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4. |
| 81 | Rotation is separate from addition to prevent recomputation. */ |
| 82 | #define FF(a, b, c, d, x, s, ac) { \ |
| 83 | (a) += F ((b), (c), (d)) + (x) + (uint32_t)(ac); \ |
| 84 | (a) = ROTATE_LEFT ((a), (s)); \ |
| 85 | (a) += (b); \ |
| 86 | } |
| 87 | #define GG(a, b, c, d, x, s, ac) { \ |
| 88 | (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \ |
| 89 | (a) = ROTATE_LEFT ((a), (s)); \ |
| 90 | (a) += (b); \ |
| 91 | } |
| 92 | #define HH(a, b, c, d, x, s, ac) { \ |
| 93 | (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \ |
| 94 | (a) = ROTATE_LEFT ((a), (s)); \ |
| 95 | (a) += (b); \ |
| 96 | } |
| 97 | #define II(a, b, c, d, x, s, ac) { \ |
| 98 | (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \ |
| 99 | (a) = ROTATE_LEFT ((a), (s)); \ |
| 100 | (a) += (b); \ |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * MD5 initialization - begins an MD5 operation, writing a new ctx. |
| 105 | */ |
| 106 | EXP_FUNC void STDCALL MD5_Init(MD5_CTX *ctx) |
| 107 | { |
| 108 | ctx->count[0] = ctx->count[1] = 0; |
| 109 | |
| 110 | /* Load magic initialization constants. |
| 111 | */ |
| 112 | ctx->state[0] = 0x67452301; |
| 113 | ctx->state[1] = 0xefcdab89; |
| 114 | ctx->state[2] = 0x98badcfe; |
| 115 | ctx->state[3] = 0x10325476; |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Accepts an array of octets as the next portion of the message. |
| 120 | */ |
| 121 | EXP_FUNC void STDCALL MD5_Update(MD5_CTX *ctx, const uint8_t * msg, int len) |
| 122 | { |
| 123 | uint32_t x; |
| 124 | int i, partLen; |
| 125 | |
| 126 | /* Compute number of bytes mod 64 */ |
| 127 | x = (uint32_t)((ctx->count[0] >> 3) & 0x3F); |
| 128 | |
| 129 | /* Update number of bits */ |
| 130 | if ((ctx->count[0] += ((uint32_t)len << 3)) < ((uint32_t)len << 3)) |
| 131 | ctx->count[1]++; |
| 132 | ctx->count[1] += ((uint32_t)len >> 29); |
| 133 | |
| 134 | partLen = 64 - x; |
| 135 | |
| 136 | /* Transform as many times as possible. */ |
| 137 | if (len >= partLen) |
| 138 | { |
| 139 | memcpy(&ctx->buffer[x], msg, partLen); |
| 140 | MD5Transform(ctx->state, ctx->buffer); |
| 141 | |
| 142 | for (i = partLen; i + 63 < len; i += 64) |
| 143 | MD5Transform(ctx->state, &msg[i]); |
| 144 | |
| 145 | x = 0; |
| 146 | } |
| 147 | else |
| 148 | i = 0; |
| 149 | |
| 150 | /* Buffer remaining input */ |
| 151 | memcpy(&ctx->buffer[x], &msg[i], len-i); |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * Return the 128-bit message digest into the user's array |
| 156 | */ |
| 157 | EXP_FUNC void STDCALL MD5_Final(uint8_t *digest, MD5_CTX *ctx) |
| 158 | { |
| 159 | uint8_t bits[8]; |
| 160 | uint32_t x, padLen; |
| 161 | |
| 162 | /* Save number of bits */ |
| 163 | Encode(bits, ctx->count, 8); |
| 164 | |
| 165 | /* Pad out to 56 mod 64. |
| 166 | */ |
| 167 | x = (uint32_t)((ctx->count[0] >> 3) & 0x3f); |
| 168 | padLen = (x < 56) ? (56 - x) : (120 - x); |
| 169 | MD5_Update(ctx, PADDING, padLen); |
| 170 | |
| 171 | /* Append length (before padding) */ |
| 172 | MD5_Update(ctx, bits, 8); |
| 173 | |
| 174 | /* Store state in digest */ |
| 175 | Encode(digest, ctx->state, MD5_SIZE); |
| 176 | } |
| 177 | |
| 178 | /** |
| 179 | * MD5 basic transformation. Transforms state based on block. |
| 180 | */ |
| 181 | static void MD5Transform(uint32_t state[4], const uint8_t block[64]) |
| 182 | { |
| 183 | uint32_t a = state[0], b = state[1], c = state[2], |
| 184 | d = state[3], x[MD5_SIZE]; |
| 185 | |
| 186 | Decode(x, block, 64); |
| 187 | |
| 188 | /* Round 1 */ |
| 189 | FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */ |
| 190 | FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */ |
| 191 | FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */ |
| 192 | FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */ |
| 193 | FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */ |
| 194 | FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */ |
| 195 | FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */ |
| 196 | FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */ |
| 197 | FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */ |
| 198 | FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */ |
| 199 | FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */ |
| 200 | FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */ |
| 201 | FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */ |
| 202 | FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */ |
| 203 | FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */ |
| 204 | FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */ |
| 205 | |
| 206 | /* Round 2 */ |
| 207 | GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */ |
| 208 | GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */ |
| 209 | GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */ |
| 210 | GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */ |
| 211 | GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */ |
| 212 | GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */ |
| 213 | GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */ |
| 214 | GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */ |
| 215 | GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */ |
| 216 | GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */ |
| 217 | GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */ |
| 218 | GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */ |
| 219 | GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */ |
| 220 | GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */ |
| 221 | GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */ |
| 222 | GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */ |
| 223 | |
| 224 | /* Round 3 */ |
| 225 | HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */ |
| 226 | HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */ |
| 227 | HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */ |
| 228 | HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */ |
| 229 | HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */ |
| 230 | HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */ |
| 231 | HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */ |
| 232 | HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */ |
| 233 | HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */ |
| 234 | HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */ |
| 235 | HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */ |
| 236 | HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */ |
| 237 | HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */ |
| 238 | HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */ |
| 239 | HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */ |
| 240 | HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */ |
| 241 | |
| 242 | /* Round 4 */ |
| 243 | II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */ |
| 244 | II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */ |
| 245 | II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */ |
| 246 | II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */ |
| 247 | II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */ |
| 248 | II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */ |
| 249 | II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */ |
| 250 | II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */ |
| 251 | II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */ |
| 252 | II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */ |
| 253 | II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */ |
| 254 | II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */ |
| 255 | II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */ |
| 256 | II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */ |
| 257 | II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */ |
| 258 | II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */ |
| 259 | |
| 260 | state[0] += a; |
| 261 | state[1] += b; |
| 262 | state[2] += c; |
| 263 | state[3] += d; |
| 264 | } |
| 265 | |
| 266 | /** |
| 267 | * Encodes input (uint32_t) into output (uint8_t). Assumes len is |
| 268 | * a multiple of 4. |
| 269 | */ |
| 270 | static void Encode(uint8_t *output, uint32_t *input, uint32_t len) |
| 271 | { |
| 272 | uint32_t i, j; |
| 273 | |
| 274 | for (i = 0, j = 0; j < len; i++, j += 4) |
| 275 | { |
| 276 | output[j] = (uint8_t)(input[i] & 0xff); |
| 277 | output[j+1] = (uint8_t)((input[i] >> 8) & 0xff); |
| 278 | output[j+2] = (uint8_t)((input[i] >> 16) & 0xff); |
| 279 | output[j+3] = (uint8_t)((input[i] >> 24) & 0xff); |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | /** |
| 284 | * Decodes input (uint8_t) into output (uint32_t). Assumes len is |
| 285 | * a multiple of 4. |
| 286 | */ |
| 287 | static void Decode(uint32_t *output, const uint8_t *input, uint32_t len) |
| 288 | { |
| 289 | uint32_t i, j; |
| 290 | |
| 291 | for (i = 0, j = 0; j < len; i++, j += 4) |
| 292 | output[i] = ((uint32_t)input[j]) | (((uint32_t)input[j+1]) << 8) | |
| 293 | (((uint32_t)input[j+2]) << 16) | (((uint32_t)input[j+3]) << 24); |
| 294 | } |