cscrypt/md5.c

   1 /*
   2  * This code implements the MD5 message-digest algorithm.
   3  * The algorithm is due to Ron Rivest. This code was
   4  * written by Colin Plumb in 1993, no copyright is claimed.
   5  * This code is in the public domain; do with it what you wish.
   6  *
   7  * ----------------------------------------------------------------------------
   8  * The md5_crypt() function was taken from freeBSD's libcrypt and contains
   9  * this license:
  10  *    "THE BEER-WARE LICENSE" (Revision 42):
  11  *     <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
  12  *     can do whatever you want with this stuff. If we meet some day, and you think
  13  *     this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
  14  *
  15  * $FreeBSD: src/lib/libcrypt/crypt.c,v 1.7.2.1 1999/08/29 14:56:33 peter Exp $
  16  *
  17  * ----------------------------------------------------------------------------
  18  * On April 19th, 2001 md5_crypt() was modified to make it reentrant
  19  * by Erik Andersen <andersen@uclibc.org>
  20  */
  21
  22 #include "../globals.h"
  23 #include "../oscam-string.h"
  24
  25 #include "md5.h"
  26
  27 #if !defined(WITH_SSL) && !defined(WITH_LIBCRYPTO)
  28
  29 #ifdef __i386__
  30 #define byteReverse(a, b)
  31 #else
  32 /*
  33  * Note: This code is harmless on little-endian machines.
  34  *       The ifdefs are just a small optimization
  35  */
  36 static void byteReverse(unsigned char *buf, unsigned int longs)
  37 {
  38         uint32_t t;
  39         do
  40         {
  41                 t = (uint32_t)((unsigned int)buf[3] << 8 | buf[2]) << 16 |
  42                         ((unsigned int)buf[1] << 8 | buf[0]);
  43                 memcpy(buf, &t, 4);
  44                 buf += 4;
  45         }
  46         while(--longs);
  47 }
  48 #endif
  49
  50 /* The four core functions - F1 is optimized somewhat */
  51
  52 /* #define F1(x, y, z) (x & y | ~x & z) */
  53 #define F1(x, y, z) (z ^ (x & (y ^ z)))
  54 #define F2(x, y, z) F1(z, x, y)
  55 #define F3(x, y, z) (x ^ y ^ z)
  56 #define F4(x, y, z) (y ^ (x | ~z))
  57
  58 /* This is the central step in the MD5 algorithm. */
  59 #define MD5STEP(f, w, x, y, z, data, s) \
  60     ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
  61
  62 /*
  63  * The core of the MD5 algorithm, this alters an existing MD5 hash to
  64  * reflect the addition of 16 longwords of new data.  MD5_Update blocks
  65  * the data and converts bytes into longwords for this routine.
  66  */
  67 static void MD5_Transform(uint32_t buf[4],  uint32_t in[16])
  68 {
  69         uint32_t a = buf[0];
  70         uint32_t b = buf[1];
  71         uint32_t c = buf[2];
  72         uint32_t d = buf[3];
  73
  74         MD5STEP(F1, a, b, c, d, in[ 0] + 0xd76aa478,  7);
  75         MD5STEP(F1, d, a, b, c, in[ 1] + 0xe8c7b756, 12);
  76         MD5STEP(F1, c, d, a, b, in[ 2] + 0x242070db, 17);
  77         MD5STEP(F1, b, c, d, a, in[ 3] + 0xc1bdceee, 22);
  78         MD5STEP(F1, a, b, c, d, in[ 4] + 0xf57c0faf,  7);
  79         MD5STEP(F1, d, a, b, c, in[ 5] + 0x4787c62a, 12);
  80         MD5STEP(F1, c, d, a, b, in[ 6] + 0xa8304613, 17);
  81         MD5STEP(F1, b, c, d, a, in[ 7] + 0xfd469501, 22);
  82         MD5STEP(F1, a, b, c, d, in[ 8] + 0x698098d8,  7);
  83         MD5STEP(F1, d, a, b, c, in[ 9] + 0x8b44f7af, 12);
  84         MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
  85         MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
  86         MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122,  7);
  87         MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
  88         MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
  89         MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
  90
  91         MD5STEP(F2, a, b, c, d, in[ 1] + 0xf61e2562,  5);
  92         MD5STEP(F2, d, a, b, c, in[ 6] + 0xc040b340,  9);
  93         MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
  94         MD5STEP(F2, b, c, d, a, in[ 0] + 0xe9b6c7aa, 20);
  95         MD5STEP(F2, a, b, c, d, in[ 5] + 0xd62f105d,  5);
  96         MD5STEP(F2, d, a, b, c, in[10] + 0x02441453,  9);
  97         MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
  98         MD5STEP(F2, b, c, d, a, in[ 4] + 0xe7d3fbc8, 20);
  99         MD5STEP(F2, a, b, c, d, in[ 9] + 0x21e1cde6,  5);
 100         MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6,  9);
 101         MD5STEP(F2, c, d, a, b, in[ 3] + 0xf4d50d87, 14);
 102         MD5STEP(F2, b, c, d, a, in[ 8] + 0x455a14ed, 20);
 103         MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905,  5);
 104         MD5STEP(F2, d, a, b, c, in[ 2] + 0xfcefa3f8,  9);
 105         MD5STEP(F2, c, d, a, b, in[ 7] + 0x676f02d9, 14);
 106         MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 107
 108         MD5STEP(F3, a, b, c, d, in[ 5] + 0xfffa3942,  4);
 109         MD5STEP(F3, d, a, b, c, in[ 8] + 0x8771f681, 11);
 110         MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 111         MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 112         MD5STEP(F3, a, b, c, d, in[ 1] + 0xa4beea44,  4);
 113         MD5STEP(F3, d, a, b, c, in[ 4] + 0x4bdecfa9, 11);
 114         MD5STEP(F3, c, d, a, b, in[ 7] + 0xf6bb4b60, 16);
 115         MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 116         MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6,  4);
 117         MD5STEP(F3, d, a, b, c, in[ 0] + 0xeaa127fa, 11);
 118         MD5STEP(F3, c, d, a, b, in[ 3] + 0xd4ef3085, 16);
 119         MD5STEP(F3, b, c, d, a, in[ 6] + 0x04881d05, 23);
 120         MD5STEP(F3, a, b, c, d, in[ 9] + 0xd9d4d039,  4);
 121         MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 122         MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 123         MD5STEP(F3, b, c, d, a, in[ 2] + 0xc4ac5665, 23);
 124
 125         MD5STEP(F4, a, b, c, d, in[ 0] + 0xf4292244,  6);
 126         MD5STEP(F4, d, a, b, c, in[ 7] + 0x432aff97, 10);
 127         MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 128         MD5STEP(F4, b, c, d, a, in[ 5] + 0xfc93a039, 21);
 129         MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3,  6);
 130         MD5STEP(F4, d, a, b, c, in[ 3] + 0x8f0ccc92, 10);
 131         MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 132         MD5STEP(F4, b, c, d, a, in[ 1] + 0x85845dd1, 21);
 133         MD5STEP(F4, a, b, c, d, in[ 8] + 0x6fa87e4f,  6);
 134         MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 135         MD5STEP(F4, c, d, a, b, in[ 6] + 0xa3014314, 15);
 136         MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 137         MD5STEP(F4, a, b, c, d, in[ 4] + 0xf7537e82,  6);
 138         MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 139         MD5STEP(F4, c, d, a, b, in[ 2] + 0x2ad7d2bb, 15);
 140         MD5STEP(F4, b, c, d, a, in[ 9] + 0xeb86d391, 21);
 141
 142         buf[0] += a;
 143         buf[1] += b;
 144         buf[2] += c;
 145         buf[3] += d;
 146 }
 147
 148 /*
 149  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 150  * initialization constants.
 151  */
 152 void MD5_Init(MD5_CTX *ctx)
 153 {
 154         ctx->buf[0] = 0x67452301;
 155         ctx->buf[1] = 0xefcdab89;
 156         ctx->buf[2] = 0x98badcfe;
 157         ctx->buf[3] = 0x10325476;
 158
 159         ctx->bits[0] = 0;
 160         ctx->bits[1] = 0;
 161 }
 162
 163 /*
 164  * Update context to reflect the concatenation of another buffer full
 165  * of bytes.
 166  */
 167 void MD5_Update(MD5_CTX *ctx, const unsigned char *buf, unsigned int len)
 168 {
 169         uint32_t t;
 170
 171         /* Update bitcount */
 172
 173         t = ctx->bits[0];
 174         if((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
 175                 { ctx->bits[1]++; }     /* Carry from low to high */
 176         ctx->bits[1] += len >> 29;
 177
 178         t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */
 179
 180         /* Handle any leading odd-sized chunks */
 181
 182         if(t)
 183         {
 184                 unsigned char *p = ((unsigned char *)ctx->in) + t;
 185                 t = 64 - t;
 186                 if(len < t)
 187                 {
 188                         memcpy(p, buf, len);
 189                         return;
 190                 }
 191                 memcpy(p, buf, t);
 192                 byteReverse((unsigned char *)ctx->in, 16);
 193                 MD5_Transform(ctx->buf, ctx->in);
 194                 buf += t;
 195                 len -= t;
 196         }
 197
 198         /* Process data in 64-byte chunks */
 199         while(len >= 64)
 200         {
 201                 memcpy(ctx->in, buf, 64);
 202                 byteReverse((unsigned char *)ctx->in, 16);
 203                 MD5_Transform(ctx->buf, ctx->in);
 204                 buf += 64;
 205                 len -= 64;
 206         }
 207
 208         /* Handle any remaining bytes of data. */
 209         memcpy(ctx->in, buf, len);
 210 }
 211
 212 /*
 213  * Final wrapup - pad to 64-byte boundary with the bit pattern
 214  * 1 0* (64-bit count of bits processed, MSB-first)
 215  */
 216 void MD5_Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5_CTX *ctx)
 217 {
 218         unsigned count;
 219         unsigned char *p;
 220
 221         /* Compute number of bytes mod 64 */
 222         count = (ctx->bits[0] >> 3) & 0x3F;
 223
 224         /* Set the first char of padding to 0x80.  This is safe since there is
 225            always at least one byte free */
 226         p = ((unsigned char *)ctx->in) + count;
 227         *p++ = 0x80;
 228
 229         /* Bytes of padding needed to make 64 bytes */
 230         count = 64 - 1 - count;
 231
 232         /* Pad out to 56 mod 64 */
 233         if(count < 8)
 234         {
 235                 /* Two lots of padding:  Pad the first block to 64 bytes */
 236                 memset(p, 0, count);
 237                 byteReverse((unsigned char *)ctx->in, 16);
 238                 MD5_Transform(ctx->buf, ctx->in);
 239
 240                 /* Now fill the next block with 56 bytes */
 241                 memset(ctx->in, 0, 56);
 242         }
 243         else
 244         {
 245                 /* Pad block to 56 bytes */
 246                 memset(p, 0, count - 8);
 247         }
 248         byteReverse((unsigned char *)ctx->in, 14);
 249
 250         /* Append length in bits and transform */
 251         uint32_t *c = ctx->in;
 252         c[14] = ctx->bits[0];
 253         c[15] = ctx->bits[1];
 254
 255         MD5_Transform(ctx->buf, ctx->in);
 256         byteReverse((unsigned char *) ctx->buf, 4);
 257
 258         memcpy(digest, ctx->buf, 16);
 259         memset(ctx, 0, sizeof(struct MD5Context)); /* In case it's sensitive */
 260 }
 261
 262 unsigned char *MD5(const unsigned char *input, unsigned long len, unsigned char *output)
 263 {
 264         MD5_CTX ctx;
 265         MD5_Init(&ctx);
 266         MD5_Update(&ctx, input, len);
 267         MD5_Final(output, &ctx);
 268         memset(&ctx, 0, sizeof(ctx)); /* security consideration */
 269         return output;
 270 }
 271 #endif
 272
 273 /* This string is magic for this algorithm.  Having
 274    it this way, we can get better later on */
 275 static const char __md5__magic[] = "$1$";
 276
 277 /* 0 ... 63 => ascii - 64 */
 278 static const unsigned char __md5_itoa64[] =
 279         "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 280
 281 static void __md5_to64(char *s, unsigned long v, int n)
 282 {
 283         while(--n >= 0)
 284         {
 285                 *s++ = __md5_itoa64[v & 0x3f];
 286                 v >>= 6;
 287         }
 288 }
 289
 290 /*
 291  * UNIX password
 292  *
 293  * Use MD5 for what it is best at...
 294  */
 295
 296 char *__md5_crypt(const char *pw, const char *salt, char *passwd)
 297 {
 298         const char *sp, *ep;
 299         char *p;
 300
 301         unsigned char   final[17];  /* final[16] exists only to aid in looping */
 302         int sl, pl, i, __md5__magic_len, pw_len;
 303         MD5_CTX ctx, ctx1;
 304         unsigned long l;
 305
 306         /* Refine the Salt first */
 307         sp = salt;
 308
 309         /* If it starts with the magic string, then skip that */
 310         __md5__magic_len = cs_strlen(__md5__magic);
 311         if(!strncmp(sp, __md5__magic, __md5__magic_len))
 312                 { sp += __md5__magic_len; }
 313
 314         /* It stops at the first '$', max 8 chars */
 315         for(ep = sp; *ep && *ep != '$' && ep < (sp + 8); ep++)
 316                 { continue; }
 317
 318         /* get the length of the true salt */
 319         sl = ep - sp;
 320
 321         MD5_Init(&ctx);
 322
 323         /* The password first, since that is what is most unknown */
 324         pw_len = cs_strlen(pw);
 325         MD5_Update(&ctx, (const unsigned char *)pw, pw_len);
 326
 327         /* Then our magic string */
 328         MD5_Update(&ctx, (const unsigned char *)__md5__magic, __md5__magic_len);
 329
 330         /* Then the raw salt */
 331         MD5_Update(&ctx, (const unsigned char *)sp, sl);
 332
 333         /* Then just as many characters of the MD5(pw,salt,pw) */
 334         MD5_Init(&ctx1);
 335         MD5_Update(&ctx1, (const unsigned char *)pw, pw_len);
 336         MD5_Update(&ctx1, (const unsigned char *)sp, sl);
 337         MD5_Update(&ctx1, (const unsigned char *)pw, pw_len);
 338         MD5_Final(final, &ctx1);
 339         for(pl = pw_len; pl > 0; pl -= 16)
 340                 { MD5_Update(&ctx, (const unsigned char *)final, pl > 16 ? 16 : pl); }
 341
 342         /* Don't leave anything around in vm they could use. */
 343         memset(final, 0, sizeof final);
 344
 345         /* Then something really weird... */
 346         for(i = pw_len; i ; i >>= 1)
 347         {
 348                 MD5_Update(&ctx, ((i & 1) ? final : (const unsigned char *) pw), 1);
 349         }
 350
 351         /* Now make the output string */
 352         strncpy(passwd, __md5__magic, 4); // This should be safe
 353         strncat(passwd, sp, sl);
 354         strcat(passwd, "$");
 355
 356         MD5_Final(final, &ctx);
 357
 358         /*
 359          * and now, just to make sure things don't run too fast
 360          * On a 60 Mhz Pentium this takes 34 msec, so you would
 361          * need 30 seconds to build a 1000 entry dictionary...
 362          */
 363         for(i = 0; i < 1000; i++)
 364         {
 365                 MD5_Init(&ctx1);
 366                 if(i & 1)
 367                         { MD5_Update(&ctx1, (const unsigned char *)pw, pw_len); }
 368                 else
 369                         { MD5_Update(&ctx1, (const unsigned char *)final, 16); }
 370
 371                 if(i % 3)
 372                         { MD5_Update(&ctx1, (const unsigned char *)sp, sl); }
 373
 374                 if(i % 7)
 375                         { MD5_Update(&ctx1, (const unsigned char *)pw, pw_len); }
 376
 377                 if(i & 1)
 378                         { MD5_Update(&ctx1, (const unsigned char *)final, 16); }
 379                 else
 380                         { MD5_Update(&ctx1, (const unsigned char *)pw, pw_len); }
 381                 MD5_Final(final, &ctx1);
 382         }
 383
 384         p = passwd + cs_strlen(passwd);
 385
 386         final[16] = final[5];
 387         for(i = 0 ; i < 5 ; i++)
 388         {
 389                 l = (final[i] << 16) | (final[i + 6] << 8) | final[i + 12];
 390                 __md5_to64(p, l, 4);
 391                 p += 4;
 392         }
 393         l = final[11];
 394         __md5_to64(p, l, 2);
 395         p += 2;
 396         *p = '\0';
 397
 398         /* Don't leave anything around in vm they could use. */
 399         memset(final, 0, sizeof final);
 400
 401         return passwd;
 402 }