1 /*
   2  * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc.
   3  * MD5 Message-Digest Algorithm (RFC 1321).
   4  *
   5  * Homepage:
   6  * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
   7  *
   8  * Author:
   9  * Alexander Peslyak, better known as Solar Designer <solar at openwall.com>
  10  *
  11  * This software was written by Alexander Peslyak in 2001.  No copyright is
  12  * claimed, and the software is hereby placed in the public domain.
  13  * In case this attempt to disclaim copyright and place the software in the
  14  * public domain is deemed null and void, then the software is
  15  * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the
  16  * general public under the following terms:
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted.
  20  *
  21  * There's ABSOLUTELY NO WARRANTY, express or implied.
  22  *
  23  * (This is a heavily cut-down "BSD license".)
  24  *
  25  * This differs from Colin Plumb's older public domain implementation in that
  26  * no exactly 32-bit integer data type is required (any 32-bit or wider
  27  * unsigned integer data type will do), there's no compile-time endianness
  28  * configuration, and the function prototypes match OpenSSL's.  No code from
  29  * Colin Plumb's implementation has been reused; this comment merely compares
  30  * the properties of the two independent implementations.
  31  *
  32  * The primary goals of this implementation are portability and ease of use.
  33  * It is meant to be fast, but not as fast as possible.  Some known
  34  * optimizations are not included to reduce source code size and avoid
  35  * compile-time configuration.
  36  */
  37 
  38 #ifndef HAVE_OPENSSL
  39 
  40 #include <string.h>
  41 
  42 #include "md5.h"
  43 
  44 /*
  45  * The basic MD5 functions.
  46  *
  47  * F and G are optimized compared to their RFC 1321 definitions for
  48  * architectures that lack an AND-NOT instruction, just like in Colin Plumb's
  49  * implementation.
  50  */
  51 #define F(x, y, z)                      ((z) ^ ((x) & ((y) ^ (z))))
  52 #define G(x, y, z)                      ((y) ^ ((z) & ((x) ^ (y))))
  53 #define H(x, y, z)                      (((x) ^ (y)) ^ (z))
  54 #define H2(x, y, z)                     ((x) ^ ((y) ^ (z)))
  55 #define I(x, y, z)                      ((y) ^ ((x) | ~(z)))
  56 
  57 /*
  58  * The MD5 transformation for all four rounds.
  59  */
  60 #define STEP(f, a, b, c, d, x, t, s) \
  61         (a) += f((b), (c), (d)) + (x) + (t); \
  62         (a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s)))); \
  63         (a) += (b);
  64 
  65 /*
  66  * SET reads 4 input bytes in little-endian byte order and stores them in a
  67  * properly aligned word in host byte order.
  68  *
  69  * The check for little-endian architectures that tolerate unaligned memory
  70  * accesses is just an optimization.  Nothing will break if it fails to detect
  71  * a suitable architecture.
  72  *
  73  * Unfortunately, this optimization may be a C strict aliasing rules violation
  74  * if the caller's data buffer has effective type that cannot be aliased by
  75  * MD5_u32plus.  In practice, this problem may occur if these MD5 routines are
  76  * inlined into a calling function, or with future and dangerously advanced
  77  * link-time optimizations.  For the time being, keeping these MD5 routines in
  78  * their own translation unit avoids the problem.
  79  */
  80 #if defined(__i386__) || defined(__x86_64__) || defined(__vax__)
  81 #define SET(n) \
  82         (*(MD5_u32plus *)&ptr[(n) * 4])
  83 #define GET(n) \
  84         SET(n)
  85 #else
  86 #define SET(n) \
  87         (ctx->block[(n)] = \
  88         (MD5_u32plus)ptr[(n) * 4] | \
  89         ((MD5_u32plus)ptr[(n) * 4 + 1] << 8) | \
  90         ((MD5_u32plus)ptr[(n) * 4 + 2] << 16) | \
  91         ((MD5_u32plus)ptr[(n) * 4 + 3] << 24))
  92 #define GET(n) \
  93         (ctx->block[(n)])
  94 #endif
  95 
  96 /*
  97  * This processes one or more 64-byte data blocks, but does NOT update the bit
  98  * counters.  There are no alignment requirements.
  99  */
 100 static const void *body(MD5_CTX *ctx, const void *data, unsigned long size)
 101 {
 102         const unsigned char *ptr;
 103         MD5_u32plus a, b, c, d;
 104         MD5_u32plus saved_a, saved_b, saved_c, saved_d;
 105 
 106         ptr = (const unsigned char *)data;
 107 
 108         a = ctx->a;
 109         b = ctx->b;
 110         c = ctx->c;
 111         d = ctx->d;
 112 
 113         do {
 114                 saved_a = a;
 115                 saved_b = b;
 116                 saved_c = c;
 117                 saved_d = d;
 118 
 119 /* Round 1 */
 120                 STEP(F, a, b, c, d, SET(0), 0xd76aa478, 7)
 121                 STEP(F, d, a, b, c, SET(1), 0xe8c7b756, 12)
 122                 STEP(F, c, d, a, b, SET(2), 0x242070db, 17)
 123                 STEP(F, b, c, d, a, SET(3), 0xc1bdceee, 22)
 124                 STEP(F, a, b, c, d, SET(4), 0xf57c0faf, 7)
 125                 STEP(F, d, a, b, c, SET(5), 0x4787c62a, 12)
 126                 STEP(F, c, d, a, b, SET(6), 0xa8304613, 17)
 127                 STEP(F, b, c, d, a, SET(7), 0xfd469501, 22)
 128                 STEP(F, a, b, c, d, SET(8), 0x698098d8, 7)
 129                 STEP(F, d, a, b, c, SET(9), 0x8b44f7af, 12)
 130                 STEP(F, c, d, a, b, SET(10), 0xffff5bb1, 17)
 131                 STEP(F, b, c, d, a, SET(11), 0x895cd7be, 22)
 132                 STEP(F, a, b, c, d, SET(12), 0x6b901122, 7)
 133                 STEP(F, d, a, b, c, SET(13), 0xfd987193, 12)
 134                 STEP(F, c, d, a, b, SET(14), 0xa679438e, 17)
 135                 STEP(F, b, c, d, a, SET(15), 0x49b40821, 22)
 136 
 137 /* Round 2 */
 138                 STEP(G, a, b, c, d, GET(1), 0xf61e2562, 5)
 139                 STEP(G, d, a, b, c, GET(6), 0xc040b340, 9)
 140                 STEP(G, c, d, a, b, GET(11), 0x265e5a51, 14)
 141                 STEP(G, b, c, d, a, GET(0), 0xe9b6c7aa, 20)
 142                 STEP(G, a, b, c, d, GET(5), 0xd62f105d, 5)
 143                 STEP(G, d, a, b, c, GET(10), 0x02441453, 9)
 144                 STEP(G, c, d, a, b, GET(15), 0xd8a1e681, 14)
 145                 STEP(G, b, c, d, a, GET(4), 0xe7d3fbc8, 20)
 146                 STEP(G, a, b, c, d, GET(9), 0x21e1cde6, 5)
 147                 STEP(G, d, a, b, c, GET(14), 0xc33707d6, 9)
 148                 STEP(G, c, d, a, b, GET(3), 0xf4d50d87, 14)
 149                 STEP(G, b, c, d, a, GET(8), 0x455a14ed, 20)
 150                 STEP(G, a, b, c, d, GET(13), 0xa9e3e905, 5)
 151                 STEP(G, d, a, b, c, GET(2), 0xfcefa3f8, 9)
 152                 STEP(G, c, d, a, b, GET(7), 0x676f02d9, 14)
 153                 STEP(G, b, c, d, a, GET(12), 0x8d2a4c8a, 20)
 154 
 155 /* Round 3 */
 156                 STEP(H, a, b, c, d, GET(5), 0xfffa3942, 4)
 157                 STEP(H2, d, a, b, c, GET(8), 0x8771f681, 11)
 158                 STEP(H, c, d, a, b, GET(11), 0x6d9d6122, 16)
 159                 STEP(H2, b, c, d, a, GET(14), 0xfde5380c, 23)
 160                 STEP(H, a, b, c, d, GET(1), 0xa4beea44, 4)
 161                 STEP(H2, d, a, b, c, GET(4), 0x4bdecfa9, 11)
 162                 STEP(H, c, d, a, b, GET(7), 0xf6bb4b60, 16)
 163                 STEP(H2, b, c, d, a, GET(10), 0xbebfbc70, 23)
 164                 STEP(H, a, b, c, d, GET(13), 0x289b7ec6, 4)
 165                 STEP(H2, d, a, b, c, GET(0), 0xeaa127fa, 11)
 166                 STEP(H, c, d, a, b, GET(3), 0xd4ef3085, 16)
 167                 STEP(H2, b, c, d, a, GET(6), 0x04881d05, 23)
 168                 STEP(H, a, b, c, d, GET(9), 0xd9d4d039, 4)
 169                 STEP(H2, d, a, b, c, GET(12), 0xe6db99e5, 11)
 170                 STEP(H, c, d, a, b, GET(15), 0x1fa27cf8, 16)
 171                 STEP(H2, b, c, d, a, GET(2), 0xc4ac5665, 23)
 172 
 173 /* Round 4 */
 174                 STEP(I, a, b, c, d, GET(0), 0xf4292244, 6)
 175                 STEP(I, d, a, b, c, GET(7), 0x432aff97, 10)
 176                 STEP(I, c, d, a, b, GET(14), 0xab9423a7, 15)
 177                 STEP(I, b, c, d, a, GET(5), 0xfc93a039, 21)
 178                 STEP(I, a, b, c, d, GET(12), 0x655b59c3, 6)
 179                 STEP(I, d, a, b, c, GET(3), 0x8f0ccc92, 10)
 180                 STEP(I, c, d, a, b, GET(10), 0xffeff47d, 15)
 181                 STEP(I, b, c, d, a, GET(1), 0x85845dd1, 21)
 182                 STEP(I, a, b, c, d, GET(8), 0x6fa87e4f, 6)
 183                 STEP(I, d, a, b, c, GET(15), 0xfe2ce6e0, 10)
 184                 STEP(I, c, d, a, b, GET(6), 0xa3014314, 15)
 185                 STEP(I, b, c, d, a, GET(13), 0x4e0811a1, 21)
 186                 STEP(I, a, b, c, d, GET(4), 0xf7537e82, 6)
 187                 STEP(I, d, a, b, c, GET(11), 0xbd3af235, 10)
 188                 STEP(I, c, d, a, b, GET(2), 0x2ad7d2bb, 15)
 189                 STEP(I, b, c, d, a, GET(9), 0xeb86d391, 21)
 190 
 191                 a += saved_a;
 192                 b += saved_b;
 193                 c += saved_c;
 194                 d += saved_d;
 195 
 196                 ptr += 64;
 197         } while (size -= 64);
 198 
 199         ctx->a = a;
 200         ctx->b = b;
 201         ctx->c = c;
 202         ctx->d = d;
 203 
 204         return ptr;
 205 }
 206 
 207 void MD5_Init(MD5_CTX *ctx)
 208 {
 209         ctx->a = 0x67452301;
 210         ctx->b = 0xefcdab89;
 211         ctx->c = 0x98badcfe;
 212         ctx->d = 0x10325476;
 213 
 214         ctx->lo = 0;
 215         ctx->hi = 0;
 216 }
 217 
 218 void MD5_Update(MD5_CTX *ctx, const void *data, unsigned long size)
 219 {
 220         MD5_u32plus saved_lo;
 221         unsigned long used, available;
 222 
 223         saved_lo = ctx->lo;
 224         if ((ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo)
 225                 ctx->hi++;
 226         ctx->hi += size >> 29;
 227 
 228         used = saved_lo & 0x3f;
 229 
 230         if (used) {
 231                 available = 64 - used;
 232 
 233                 if (size < available) {
 234                         memcpy(&ctx->buffer[used], data, size);
 235                         return;
 236                 }
 237 
 238                 memcpy(&ctx->buffer[used], data, available);
 239                 data = (const unsigned char *)data + available;
 240                 size -= available;
 241                 body(ctx, ctx->buffer, 64);
 242         }
 243 
 244         if (size >= 64) {
 245                 data = body(ctx, data, size & ~(unsigned long)0x3f);
 246                 size &= 0x3f;
 247         }
 248 
 249         memcpy(ctx->buffer, data, size);
 250 }
 251 
 252 #define OUT(dst, src) \
 253         (dst)[0] = (unsigned char)(src); \
 254         (dst)[1] = (unsigned char)((src) >> 8); \
 255         (dst)[2] = (unsigned char)((src) >> 16); \
 256         (dst)[3] = (unsigned char)((src) >> 24);
 257 
 258 void MD5_Final(unsigned char *result, MD5_CTX *ctx)
 259 {
 260         unsigned long used, available;
 261 
 262         used = ctx->lo & 0x3f;
 263 
 264         ctx->buffer[used++] = 0x80;
 265 
 266         available = 64 - used;
 267 
 268         if (available < 8) {
 269                 memset(&ctx->buffer[used], 0, available);
 270                 body(ctx, ctx->buffer, 64);
 271                 used = 0;
 272                 available = 64;
 273         }
 274 
 275         memset(&ctx->buffer[used], 0, available - 8);
 276 
 277         ctx->lo <<= 3;
 278         OUT(&ctx->buffer[56], ctx->lo)
 279         OUT(&ctx->buffer[60], ctx->hi)
 280 
 281         body(ctx, ctx->buffer, 64);
 282 
 283         OUT(&result[0], ctx->a)
 284         OUT(&result[4], ctx->b)
 285         OUT(&result[8], ctx->c)
 286         OUT(&result[12], ctx->d)
 287 
 288         memset(ctx, 0, sizeof(*ctx));
 289 }
 290 
 291 #endif