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  * Equivalent code is available from RSA Data Security, Inc.

     8  * This code has been tested against that, and is equivalent,

     9  * except that you don't need to include two pages of legalese

    10  * with every copy.

    11  *

    12  * To compute the message digest of a chunk of bytes, declare an

    13  * MD5Context structure, pass it to MD5Init, call MD5Update as

    14  * needed on buffers full of bytes, and then call MD5Final, which

    15  * will fill a supplied 16-byte array with the digest.

    16  */

    17 

    18 /* Brutally hacked by John Walker back from ANSI C to K&R (no

    19    prototypes) to maintain the tradition that Netfone will compile

    20    with Sun's original "cc". */

    21 

    22 #include <string.h>             /* for memcpy() */

    23 #include <glib.h>

    24 #include "md5.h"

    25 

    26 #if G_BYTE_ORDER == G_BIG_ENDIAN

    27 #define HIGHFIRST

    28 #endif

    29 

    30 #ifndef HIGHFIRST

    31 #define byteReverse(buf, len)   /* Nothing */

    32 #else

    33 /*

    34  * Note: this code is harmless on little-endian machines.

    35  */

    36 void

    37 byteReverse (buf, longs)

    38      unsigned char *buf;

    39      unsigned longs;

    40 {

    41   uint32 t;

    42 

    43   do {

    44     t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |

    45         ((unsigned) buf[1] << 8 | buf[0]);

    46     *(uint32 *) buf = t;

    47     buf += 4;

    48   } while (--longs);

    49 }

    50 #endif

    51 

    52 /*

    53  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious

    54  * initialization constants.

    55  */

    56 void

    57 MD5Init (ctx)

    58      struct MD5Context *ctx;

    59 {

    60   ctx->buf[0] = 0x67452301;

    61   ctx->buf[1] = 0xefcdab89;

    62   ctx->buf[2] = 0x98badcfe;

    63   ctx->buf[3] = 0x10325476;

    64 

    65   ctx->bits[0] = 0;

    66   ctx->bits[1] = 0;

    67 }

    68 

    69 /*

    70  * Update context to reflect the concatenation of another buffer full

    71  * of bytes.

    72  */

    73 void

    74 MD5Update (ctx, buf, len)

    75      struct MD5Context *ctx;

    76      const char *buf;

    77      unsigned len;

    78 {

    79   uint32 t;

    80 

    81   /* Update bitcount */

    82 

    83   t = ctx->bits[0];

    84   if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)

    85     ctx->bits[1]++;             /* Carry from low to high */

    86   ctx->bits[1] += len >> 29;

    87 

    88   t = (t >> 3) & 0x3f;          /* Bytes already in shsInfo->data */

    89 

    90   /* Handle any leading odd-sized chunks */

    91 

    92   if (t) {

    93     unsigned char *p = (unsigned char *) ctx->in + t;

    94 

    95     t = 64 - t;

    96     if (len < t) {

    97       memcpy (p, buf, len);

    98       return;

    99     }

   100     memcpy (p, buf, t);

   101     byteReverse (ctx->in, 16);

   102     MD5Transform (ctx->buf, (uint32 *) ctx->in);

   103     buf += t;

   104     len -= t;

   105   }

   106   /* Process data in 64-byte chunks */

   107 

   108   while (len >= 64) {

   109     memcpy (ctx->in, buf, 64);

   110     byteReverse (ctx->in, 16);

   111     MD5Transform (ctx->buf, (uint32 *) ctx->in);

   112     buf += 64;

   113     len -= 64;

   114   }

   115 

   116   /* Handle any remaining bytes of data. */

   117 

   118   memcpy (ctx->in, buf, len);

   119 }

   120 

   121 /*

   122  * Final wrapup - pad to 64-byte boundary with the bit pattern 

   123  * 1 0* (64-bit count of bits processed, MSB-first)

   124  */

   125 void

   126 MD5Final (digest, ctx)

   127      unsigned char digest[16];

   128      struct MD5Context *ctx;

   129 {

   130   unsigned count;

   131   unsigned char *p;

   132 

   133   /* Compute number of bytes mod 64 */

   134   count = (ctx->bits[0] >> 3) & 0x3F;

   135 

   136   /* Set the first char of padding to 0x80.  This is safe since there is

   137      always at least one byte free */

   138   p = ctx->in + count;

   139   *p++ = 0x80;

   140 

   141   /* Bytes of padding needed to make 64 bytes */

   142   count = 64 - 1 - count;

   143 

   144   /* Pad out to 56 mod 64 */

   145   if (count < 8) {

   146     /* Two lots of padding:  Pad the first block to 64 bytes */

   147     memset (p, 0, count);

   148     byteReverse (ctx->in, 16);

   149     MD5Transform (ctx->buf, (uint32 *) ctx->in);

   150 

   151     /* Now fill the next block with 56 bytes */

   152     memset (ctx->in, 0, 56);

   153   } else {

   154     /* Pad block to 56 bytes */

   155     memset (p, 0, count - 8);

   156   }

   157   byteReverse (ctx->in, 14);

   158 

   159   /* Append length in bits and transform */

   160   ((uint32 *) ctx->in)[14] = ctx->bits[0];

   161   ((uint32 *) ctx->in)[15] = ctx->bits[1];

   162 

   163   MD5Transform (ctx->buf, (uint32 *) ctx->in);

   164   byteReverse ((unsigned char *) ctx->buf, 4);

   165   memcpy (digest, ctx->buf, 16);

   166   memset (ctx, 0, sizeof (ctx));        /* In case it's sensitive */

   167 }

   168 

   169 

   170 /* The four core functions - F1 is optimized somewhat */

   171 

   172 /* #define F1(x, y, z) (x & y | ~x & z) */

   173 #define F1(x, y, z) (z ^ (x & (y ^ z)))

   174 #define F2(x, y, z) F1(z, x, y)

   175 #define F3(x, y, z) (x ^ y ^ z)

   176 #define F4(x, y, z) (y ^ (x | ~z))

   177 

   178 /* This is the central step in the MD5 algorithm. */

   179 #define MD5STEP(f, w, x, y, z, data, s) \

   180 	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

   181 

   182 /*

   183  * The core of the MD5 algorithm, this alters an existing MD5 hash to

   184  * reflect the addition of 16 longwords of new data.  MD5Update blocks

   185  * the data and converts bytes into longwords for this routine.

   186  */

   187 void

   188 MD5Transform (buf, in)

   189      uint32 buf[4];

   190      uint32 in[16];

   191 {

   192   register uint32 a, b, c, d;

   193 

   194   a = buf[0];

   195   b = buf[1];

   196   c = buf[2];

   197   d = buf[3];

   198 

   199   MD5STEP (F1, a, b, c, d, in[0] + 0xd76aa478, 7);

   200   MD5STEP (F1, d, a, b, c, in[1] + 0xe8c7b756, 12);

   201   MD5STEP (F1, c, d, a, b, in[2] + 0x242070db, 17);

   202   MD5STEP (F1, b, c, d, a, in[3] + 0xc1bdceee, 22);

   203   MD5STEP (F1, a, b, c, d, in[4] + 0xf57c0faf, 7);

   204   MD5STEP (F1, d, a, b, c, in[5] + 0x4787c62a, 12);

   205   MD5STEP (F1, c, d, a, b, in[6] + 0xa8304613, 17);

   206   MD5STEP (F1, b, c, d, a, in[7] + 0xfd469501, 22);

   207   MD5STEP (F1, a, b, c, d, in[8] + 0x698098d8, 7);

   208   MD5STEP (F1, d, a, b, c, in[9] + 0x8b44f7af, 12);

   209   MD5STEP (F1, c, d, a, b, in[10] + 0xffff5bb1, 17);

   210   MD5STEP (F1, b, c, d, a, in[11] + 0x895cd7be, 22);

   211   MD5STEP (F1, a, b, c, d, in[12] + 0x6b901122, 7);

   212   MD5STEP (F1, d, a, b, c, in[13] + 0xfd987193, 12);

   213   MD5STEP (F1, c, d, a, b, in[14] + 0xa679438e, 17);

   214   MD5STEP (F1, b, c, d, a, in[15] + 0x49b40821, 22);

   215 

   216   MD5STEP (F2, a, b, c, d, in[1] + 0xf61e2562, 5);

   217   MD5STEP (F2, d, a, b, c, in[6] + 0xc040b340, 9);

   218   MD5STEP (F2, c, d, a, b, in[11] + 0x265e5a51, 14);

   219   MD5STEP (F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);

   220   MD5STEP (F2, a, b, c, d, in[5] + 0xd62f105d, 5);

   221   MD5STEP (F2, d, a, b, c, in[10] + 0x02441453, 9);

   222   MD5STEP (F2, c, d, a, b, in[15] + 0xd8a1e681, 14);

   223   MD5STEP (F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);

   224   MD5STEP (F2, a, b, c, d, in[9] + 0x21e1cde6, 5);

   225   MD5STEP (F2, d, a, b, c, in[14] + 0xc33707d6, 9);

   226   MD5STEP (F2, c, d, a, b, in[3] + 0xf4d50d87, 14);

   227   MD5STEP (F2, b, c, d, a, in[8] + 0x455a14ed, 20);

   228   MD5STEP (F2, a, b, c, d, in[13] + 0xa9e3e905, 5);

   229   MD5STEP (F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);

   230   MD5STEP (F2, c, d, a, b, in[7] + 0x676f02d9, 14);

   231   MD5STEP (F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

   232 

   233   MD5STEP (F3, a, b, c, d, in[5] + 0xfffa3942, 4);

   234   MD5STEP (F3, d, a, b, c, in[8] + 0x8771f681, 11);

   235   MD5STEP (F3, c, d, a, b, in[11] + 0x6d9d6122, 16);

   236   MD5STEP (F3, b, c, d, a, in[14] + 0xfde5380c, 23);

   237   MD5STEP (F3, a, b, c, d, in[1] + 0xa4beea44, 4);

   238   MD5STEP (F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);

   239   MD5STEP (F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);

   240   MD5STEP (F3, b, c, d, a, in[10] + 0xbebfbc70, 23);

   241   MD5STEP (F3, a, b, c, d, in[13] + 0x289b7ec6, 4);

   242   MD5STEP (F3, d, a, b, c, in[0] + 0xeaa127fa, 11);

   243   MD5STEP (F3, c, d, a, b, in[3] + 0xd4ef3085, 16);

   244   MD5STEP (F3, b, c, d, a, in[6] + 0x04881d05, 23);

   245   MD5STEP (F3, a, b, c, d, in[9] + 0xd9d4d039, 4);

   246   MD5STEP (F3, d, a, b, c, in[12] + 0xe6db99e5, 11);

   247   MD5STEP (F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);

   248   MD5STEP (F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

   249 

   250   MD5STEP (F4, a, b, c, d, in[0] + 0xf4292244, 6);

   251   MD5STEP (F4, d, a, b, c, in[7] + 0x432aff97, 10);

   252   MD5STEP (F4, c, d, a, b, in[14] + 0xab9423a7, 15);

   253   MD5STEP (F4, b, c, d, a, in[5] + 0xfc93a039, 21);

   254   MD5STEP (F4, a, b, c, d, in[12] + 0x655b59c3, 6);

   255   MD5STEP (F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);

   256   MD5STEP (F4, c, d, a, b, in[10] + 0xffeff47d, 15);

   257   MD5STEP (F4, b, c, d, a, in[1] + 0x85845dd1, 21);

   258   MD5STEP (F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);

   259   MD5STEP (F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);

   260   MD5STEP (F4, c, d, a, b, in[6] + 0xa3014314, 15);

   261   MD5STEP (F4, b, c, d, a, in[13] + 0x4e0811a1, 21);

   262   MD5STEP (F4, a, b, c, d, in[4] + 0xf7537e82, 6);

   263   MD5STEP (F4, d, a, b, c, in[11] + 0xbd3af235, 10);

   264   MD5STEP (F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);

   265   MD5STEP (F4, b, c, d, a, in[9] + 0xeb86d391, 21);

   266 

   267   buf[0] += a;

   268   buf[1] += b;

   269   buf[2] += c;

   270   buf[3] += d;

   271 }