1/* md5.c - MD5 Message-Digest Algorithm 2 * Copyright (C) 1995,1996,1998,1999,2001,2002, 3 * 2003 Free Software Foundation, Inc. 4 * 5 * This file is part of Libgcrypt. 6 * 7 * Libgcrypt is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU Lesser General Public License as 9 * published by the Free Software Foundation; either version 2.1 of 10 * the License, or (at your option) any later version. 11 * 12 * Libgcrypt is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 20 * 21 * According to the definition of MD5 in RFC 1321 from April 1992. 22 * NOTE: This is *not* the same file as the one from glibc. 23 * Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995. 24 * heavily modified for GnuPG by Werner Koch <wk@gnupg.org> 25 */ 26 27/* Test values: 28 * "" D4 1D 8C D9 8F 00 B2 04 E9 80 09 98 EC F8 42 7E 29 * "a" 0C C1 75 B9 C0 F1 B6 A8 31 C3 99 E2 69 77 26 61 30 * "abc 90 01 50 98 3C D2 4F B0 D6 96 3F 7D 28 E1 7F 72 31 * "message digest" F9 6B 69 7D 7C B7 93 8D 52 5A 2F 31 AA F1 61 D0 32 */ 33 34#include <config.h> 35#include <stdio.h> 36#include <stdlib.h> 37#include <string.h> 38 39#include "g10lib.h" 40#include "cipher.h" 41 42#include "bithelp.h" 43 44 45typedef struct { 46 u32 A,B,C,D; /* chaining variables */ 47 u32 nblocks; 48 byte buf[64]; 49 int count; 50} MD5_CONTEXT; 51 52 53static void 54md5_init( void *context ) 55{ 56 MD5_CONTEXT *ctx = context; 57 58 ctx->A = 0x67452301; 59 ctx->B = 0xefcdab89; 60 ctx->C = 0x98badcfe; 61 ctx->D = 0x10325476; 62 63 ctx->nblocks = 0; 64 ctx->count = 0; 65} 66 67 68/* These are the four functions used in the four steps of the MD5 algorithm 69 and defined in the RFC 1321. The first function is a little bit optimized 70 (as found in Colin Plumbs public domain implementation). */ 71/* #define FF(b, c, d) ((b & c) | (~b & d)) */ 72#define FF(b, c, d) (d ^ (b & (c ^ d))) 73#define FG(b, c, d) FF (d, b, c) 74#define FH(b, c, d) (b ^ c ^ d) 75#define FI(b, c, d) (c ^ (b | ~d)) 76 77 78/**************** 79 * transform n*64 bytes 80 */ 81static void 82transform ( MD5_CONTEXT *ctx, const unsigned char *data ) 83{ 84 u32 correct_words[16]; 85 register u32 A = ctx->A; 86 register u32 B = ctx->B; 87 register u32 C = ctx->C; 88 register u32 D = ctx->D; 89 u32 *cwp = correct_words; 90 91#ifdef WORDS_BIGENDIAN 92 { 93 int i; 94 byte *p2, *p1; 95 for(i=0, p1=data, p2=(byte*)correct_words; i < 16; i++, p2 += 4 ) 96 { 97 p2[3] = *p1++; 98 p2[2] = *p1++; 99 p2[1] = *p1++; 100 p2[0] = *p1++; 101 } 102 } 103#else 104 memcpy( correct_words, data, 64 ); 105#endif 106 107 108#define OP(a, b, c, d, s, T) \ 109 do \ 110 { \ 111 a += FF (b, c, d) + (*cwp++) + T; \ 112 a = rol(a, s); \ 113 a += b; \ 114 } \ 115 while (0) 116 117 /* Before we start, one word about the strange constants. 118 They are defined in RFC 1321 as 119 120 T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64 121 */ 122 123 /* Round 1. */ 124 OP (A, B, C, D, 7, 0xd76aa478); 125 OP (D, A, B, C, 12, 0xe8c7b756); 126 OP (C, D, A, B, 17, 0x242070db); 127 OP (B, C, D, A, 22, 0xc1bdceee); 128 OP (A, B, C, D, 7, 0xf57c0faf); 129 OP (D, A, B, C, 12, 0x4787c62a); 130 OP (C, D, A, B, 17, 0xa8304613); 131 OP (B, C, D, A, 22, 0xfd469501); 132 OP (A, B, C, D, 7, 0x698098d8); 133 OP (D, A, B, C, 12, 0x8b44f7af); 134 OP (C, D, A, B, 17, 0xffff5bb1); 135 OP (B, C, D, A, 22, 0x895cd7be); 136 OP (A, B, C, D, 7, 0x6b901122); 137 OP (D, A, B, C, 12, 0xfd987193); 138 OP (C, D, A, B, 17, 0xa679438e); 139 OP (B, C, D, A, 22, 0x49b40821); 140 141#undef OP 142#define OP(f, a, b, c, d, k, s, T) \ 143 do \ 144 { \ 145 a += f (b, c, d) + correct_words[k] + T; \ 146 a = rol(a, s); \ 147 a += b; \ 148 } \ 149 while (0) 150 151 /* Round 2. */ 152 OP (FG, A, B, C, D, 1, 5, 0xf61e2562); 153 OP (FG, D, A, B, C, 6, 9, 0xc040b340); 154 OP (FG, C, D, A, B, 11, 14, 0x265e5a51); 155 OP (FG, B, C, D, A, 0, 20, 0xe9b6c7aa); 156 OP (FG, A, B, C, D, 5, 5, 0xd62f105d); 157 OP (FG, D, A, B, C, 10, 9, 0x02441453); 158 OP (FG, C, D, A, B, 15, 14, 0xd8a1e681); 159 OP (FG, B, C, D, A, 4, 20, 0xe7d3fbc8); 160 OP (FG, A, B, C, D, 9, 5, 0x21e1cde6); 161 OP (FG, D, A, B, C, 14, 9, 0xc33707d6); 162 OP (FG, C, D, A, B, 3, 14, 0xf4d50d87); 163 OP (FG, B, C, D, A, 8, 20, 0x455a14ed); 164 OP (FG, A, B, C, D, 13, 5, 0xa9e3e905); 165 OP (FG, D, A, B, C, 2, 9, 0xfcefa3f8); 166 OP (FG, C, D, A, B, 7, 14, 0x676f02d9); 167 OP (FG, B, C, D, A, 12, 20, 0x8d2a4c8a); 168 169 /* Round 3. */ 170 OP (FH, A, B, C, D, 5, 4, 0xfffa3942); 171 OP (FH, D, A, B, C, 8, 11, 0x8771f681); 172 OP (FH, C, D, A, B, 11, 16, 0x6d9d6122); 173 OP (FH, B, C, D, A, 14, 23, 0xfde5380c); 174 OP (FH, A, B, C, D, 1, 4, 0xa4beea44); 175 OP (FH, D, A, B, C, 4, 11, 0x4bdecfa9); 176 OP (FH, C, D, A, B, 7, 16, 0xf6bb4b60); 177 OP (FH, B, C, D, A, 10, 23, 0xbebfbc70); 178 OP (FH, A, B, C, D, 13, 4, 0x289b7ec6); 179 OP (FH, D, A, B, C, 0, 11, 0xeaa127fa); 180 OP (FH, C, D, A, B, 3, 16, 0xd4ef3085); 181 OP (FH, B, C, D, A, 6, 23, 0x04881d05); 182 OP (FH, A, B, C, D, 9, 4, 0xd9d4d039); 183 OP (FH, D, A, B, C, 12, 11, 0xe6db99e5); 184 OP (FH, C, D, A, B, 15, 16, 0x1fa27cf8); 185 OP (FH, B, C, D, A, 2, 23, 0xc4ac5665); 186 187 /* Round 4. */ 188 OP (FI, A, B, C, D, 0, 6, 0xf4292244); 189 OP (FI, D, A, B, C, 7, 10, 0x432aff97); 190 OP (FI, C, D, A, B, 14, 15, 0xab9423a7); 191 OP (FI, B, C, D, A, 5, 21, 0xfc93a039); 192 OP (FI, A, B, C, D, 12, 6, 0x655b59c3); 193 OP (FI, D, A, B, C, 3, 10, 0x8f0ccc92); 194 OP (FI, C, D, A, B, 10, 15, 0xffeff47d); 195 OP (FI, B, C, D, A, 1, 21, 0x85845dd1); 196 OP (FI, A, B, C, D, 8, 6, 0x6fa87e4f); 197 OP (FI, D, A, B, C, 15, 10, 0xfe2ce6e0); 198 OP (FI, C, D, A, B, 6, 15, 0xa3014314); 199 OP (FI, B, C, D, A, 13, 21, 0x4e0811a1); 200 OP (FI, A, B, C, D, 4, 6, 0xf7537e82); 201 OP (FI, D, A, B, C, 11, 10, 0xbd3af235); 202 OP (FI, C, D, A, B, 2, 15, 0x2ad7d2bb); 203 OP (FI, B, C, D, A, 9, 21, 0xeb86d391); 204 205 /* Put checksum in context given as argument. */ 206 ctx->A += A; 207 ctx->B += B; 208 ctx->C += C; 209 ctx->D += D; 210} 211 212 213 214/* The routine updates the message-digest context to 215 * account for the presence of each of the characters inBuf[0..inLen-1] 216 * in the message whose digest is being computed. 217 */ 218static void 219md5_write( void *context, const void *inbuf_arg , size_t inlen) 220{ 221 const unsigned char *inbuf = inbuf_arg; 222 MD5_CONTEXT *hd = context; 223 224 if( hd->count == 64 ) /* flush the buffer */ 225 { 226 transform( hd, hd->buf ); 227 _gcry_burn_stack (80+6*sizeof(void*)); 228 hd->count = 0; 229 hd->nblocks++; 230 } 231 if( !inbuf ) 232 return; 233 234 if( hd->count ) 235 { 236 for( ; inlen && hd->count < 64; inlen-- ) 237 hd->buf[hd->count++] = *inbuf++; 238 md5_write( hd, NULL, 0 ); 239 if( !inlen ) 240 return; 241 } 242 _gcry_burn_stack (80+6*sizeof(void*)); 243 244 while( inlen >= 64 ) 245 { 246 transform( hd, inbuf ); 247 hd->count = 0; 248 hd->nblocks++; 249 inlen -= 64; 250 inbuf += 64; 251 } 252 for( ; inlen && hd->count < 64; inlen-- ) 253 hd->buf[hd->count++] = *inbuf++; 254 255} 256 257 258 259/* The routine final terminates the message-digest computation and 260 * ends with the desired message digest in mdContext->digest[0...15]. 261 * The handle is prepared for a new MD5 cycle. 262 * Returns 16 bytes representing the digest. 263 */ 264 265static void 266md5_final( void *context) 267{ 268 MD5_CONTEXT *hd = context; 269 u32 t, msb, lsb; 270 byte *p; 271 272 md5_write(hd, NULL, 0); /* flush */; 273 274 t = hd->nblocks; 275 /* multiply by 64 to make a byte count */ 276 lsb = t << 6; 277 msb = t >> 26; 278 /* add the count */ 279 t = lsb; 280 if( (lsb += hd->count) < t ) 281 msb++; 282 /* multiply by 8 to make a bit count */ 283 t = lsb; 284 lsb <<= 3; 285 msb <<= 3; 286 msb |= t >> 29; 287 288 if( hd->count < 56 ) /* enough room */ 289 { 290 hd->buf[hd->count++] = 0x80; /* pad */ 291 while( hd->count < 56 ) 292 hd->buf[hd->count++] = 0; /* pad */ 293 } 294 else /* need one extra block */ 295 { 296 hd->buf[hd->count++] = 0x80; /* pad character */ 297 while( hd->count < 64 ) 298 hd->buf[hd->count++] = 0; 299 md5_write(hd, NULL, 0); /* flush */; 300 memset(hd->buf, 0, 56 ); /* fill next block with zeroes */ 301 } 302 /* append the 64 bit count */ 303 hd->buf[56] = lsb ; 304 hd->buf[57] = lsb >> 8; 305 hd->buf[58] = lsb >> 16; 306 hd->buf[59] = lsb >> 24; 307 hd->buf[60] = msb ; 308 hd->buf[61] = msb >> 8; 309 hd->buf[62] = msb >> 16; 310 hd->buf[63] = msb >> 24; 311 transform( hd, hd->buf ); 312 _gcry_burn_stack (80+6*sizeof(void*)); 313 314 p = hd->buf; 315#ifdef WORDS_BIGENDIAN 316#define X(a) do { *p++ = hd->a ; *p++ = hd->a >> 8; \ 317 *p++ = hd->a >> 16; *p++ = hd->a >> 24; } while(0) 318#else /* little endian */ 319#define X(a) do { *(u32*)p = (*hd).a ; p += 4; } while(0) 320#endif 321 X(A); 322 X(B); 323 X(C); 324 X(D); 325#undef X 326 327} 328 329static byte * 330md5_read( void *context ) 331{ 332 MD5_CONTEXT *hd = (MD5_CONTEXT *) context; 333 return hd->buf; 334} 335 336static byte asn[18] = /* Object ID is 1.2.840.113549.2.5 */ 337 { 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a, 0x86,0x48, 338 0x86, 0xf7, 0x0d, 0x02, 0x05, 0x05, 0x00, 0x04, 0x10 }; 339 340static gcry_md_oid_spec_t oid_spec_md5[] = 341 { 342 /* iso.member-body.us.rsadsi.pkcs.pkcs-1.4 (md5WithRSAEncryption) */ 343 { "1.2.840.113549.1.1.4" }, 344 /* RSADSI digestAlgorithm MD5 */ 345 { "1.2.840.113549.2.5" }, 346 { NULL }, 347 }; 348 349gcry_md_spec_t _gcry_digest_spec_md5 = 350 { 351 "MD5", asn, DIM (asn), oid_spec_md5, 16, 352 md5_init, md5_write, md5_final, md5_read, 353 sizeof (MD5_CONTEXT) 354 }; 355