md5.c

/* MD5 Message Digest algorithm */

#include "md5.h"

/* Prototypes */
static void Transform(UINT_32 *, UINT_32 *);

static unsigned char PADDING[64] = {
   0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

/* F, G and H are basic MD5 functions: selection, majority, parity */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4 */
/* Rotation is separate from addition to prevent recomputation */
#define FF(a, b, c, d, x, s, ac) { \
   (a) += F ((b), (c), (d)) + (x) + (UINT_32)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }

#define GG(a, b, c, d, x, s, ac) { \
   (a) += G ((b), (c), (d)) + (x) + (UINT_32)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }

#define HH(a, b, c, d, x, s, ac) { \
   (a) += H ((b), (c), (d)) + (x) + (UINT_32)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }

#define II(a, b, c, d, x, s, ac) { \
   (a) += I ((b), (c), (d)) + (x) + (UINT_32)(ac); \
   (a) = ROTATE_LEFT ((a), (s)); (a) += (b); }

void MD5Init(MD5_CTX *mdContext)
{
   mdContext->i[0] = mdContext->i[1] = (UINT_32) 0;

   /* Load magic initialization constants. */
   mdContext->buf[0] = (UINT_32) 0x67452301;
   mdContext->buf[1] = (UINT_32) 0xefcdab89;
   mdContext->buf[2] = (UINT_32) 0x98badcfe;
   mdContext->buf[3] = (UINT_32) 0x10325476;
}

void MD5Update(MD5_CTX *mdContext, unsigned char *inBuf, unsigned int inLen)
{
   unsigned int i, ii;
   UINT_32 in[16];
   int mdi;

   /* compute number of bytes mod 64 */
   mdi = (int) ((mdContext->i[0] >> 3) & 0x3F);

   /* update number of bits */
   if ((mdContext->i[0] + ((UINT_32) inLen << 3)) < mdContext->i[0])
      mdContext->i[1]++;
   mdContext->i[0] += ((UINT_32) inLen << 3);
   mdContext->i[1] += ((UINT_32) inLen >> 29);

   while (inLen--) {
      /* add new character to buffer, increment mdi */
      mdContext->in[mdi++] = *inBuf++;

      /* transform if necessary */
      if (mdi == 0x40) {
	 for (i = 0, ii = 0; i < 16; i++, ii += 4)
	    in[i] = (((UINT_32) mdContext->in[ii + 3]) << 24) |
	       (((UINT_32) mdContext->in[ii + 2]) << 16) |
	       (((UINT_32) mdContext->in[ii + 1]) << 8) |
	       ((UINT_32) mdContext->in[ii]);
	 Transform(mdContext->buf, in);
	 mdi = 0;
      }
   }
}

void MD5Final(MD5_CTX *mdContext)
{
   UINT_32 in[16];
   unsigned int i, ii;
   unsigned int padLen;
   int mdi;

   /* save number of bits */
   in[14] = mdContext->i[0];
   in[15] = mdContext->i[1];

   /* compute number of bytes mod 64 */
   mdi = (int) ((mdContext->i[0] >> 3) & 0x3F);

   /* pad out to 56 mod 64 */
   padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi);
   MD5Update(mdContext, PADDING, padLen);

   /* append length in bits and transform */
   for (i = 0, ii = 0; i < 14; i++, ii += 4)
      in[i] = (((UINT_32) mdContext->in[ii + 3]) << 24) |
	 (((UINT_32) mdContext->in[ii + 2]) << 16) |
	 (((UINT_32) mdContext->in[ii + 1]) << 8) |
	 ((UINT_32) mdContext->in[ii]);
   Transform(mdContext->buf, in);

   /* store buffer in digest */
   for (i = 0, ii = 0; i < 4; i++, ii += 4) {
      mdContext->digest[ii] = (unsigned char) (mdContext->buf[i] & 0xFF);
      mdContext->digest[ii + 1] =
	 (unsigned char) ((mdContext->buf[i] >> 8) & 0xFF);
      mdContext->digest[ii + 2] =
	 (unsigned char) ((mdContext->buf[i] >> 16) & 0xFF);
      mdContext->digest[ii + 3] =
	 (unsigned char) ((mdContext->buf[i] >> 24) & 0xFF);
   }
}

/* Basic MD5 step. Transform buf based on in. */
static void Transform(UINT_32 *buf, UINT_32 *in)
{
   UINT_32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];

   /* Round 1 */
#define S11 7
#define S12 12
#define S13 17
#define S14 22
   FF (a, b, c, d, in[ 0], S11, 0xd76aa478); /* 1 */
   FF (d, a, b, c, in[ 1], S12, 0xe8c7b756); /* 2 */
   FF (c, d, a, b, in[ 2], S13, 0x242070db); /* 3 */
   FF (b, c, d, a, in[ 3], S14, 0xc1bdceee); /* 4 */
   FF (a, b, c, d, in[ 4], S11, 0xf57c0faf); /* 5 */
   FF (d, a, b, c, in[ 5], S12, 0x4787c62a); /* 6 */
   FF (c, d, a, b, in[ 6], S13, 0xa8304613); /* 7 */
   FF (b, c, d, a, in[ 7], S14, 0xfd469501); /* 8 */
   FF (a, b, c, d, in[ 8], S11, 0x698098d8); /* 9 */
   FF (d, a, b, c, in[ 9], S12, 0x8b44f7af); /* 10 */
   FF (c, d, a, b, in[10], S13, 0xffff5bb1); /* 11 */
   FF (b, c, d, a, in[11], S14, 0x895cd7be); /* 12 */
   FF (a, b, c, d, in[12], S11, 0x6b901122); /* 13 */
   FF (d, a, b, c, in[13], S12, 0xfd987193); /* 14 */
   FF (c, d, a, b, in[14], S13, 0xa679438e); /* 15 */
   FF (b, c, d, a, in[15], S14, 0x49b40821); /* 16 */

   /* Round 2 */
#define S21 5
#define S22 9
#define S23 14
#define S24 20
   GG (a, b, c, d, in[ 1], S21, 0xf61e2562); /* 17 */
   GG (d, a, b, c, in[ 6], S22, 0xc040b340); /* 18 */
   GG (c, d, a, b, in[11], S23, 0x265e5a51); /* 19 */
   GG (b, c, d, a, in[ 0], S24, 0xe9b6c7aa); /* 20 */
   GG (a, b, c, d, in[ 5], S21, 0xd62f105d); /* 21 */
   GG (d, a, b, c, in[10], S22, 0x2441453 ); /* 22 */
   GG (c, d, a, b, in[15], S23, 0xd8a1e681); /* 23 */
   GG (b, c, d, a, in[ 4], S24, 0xe7d3fbc8); /* 24 */
   GG (a, b, c, d, in[ 9], S21, 0x21e1cde6); /* 25 */
   GG (d, a, b, c, in[14], S22, 0xc33707d6); /* 26 */
   GG (c, d, a, b, in[ 3], S23, 0xf4d50d87); /* 27 */
   GG (b, c, d, a, in[ 8], S24, 0x455a14ed); /* 28 */
   GG (a, b, c, d, in[13], S21, 0xa9e3e905); /* 29 */
   GG (d, a, b, c, in[ 2], S22, 0xfcefa3f8); /* 30 */
   GG (c, d, a, b, in[ 7], S23, 0x676f02d9); /* 31 */
   GG (b, c, d, a, in[12], S24, 0x8d2a4c8a); /* 32 */

   /* Round 3 */
#define S31 4
#define S32 11
#define S33 16
#define S34 23
   HH (a, b, c, d, in[ 5], S31, 0xfffa3942); /* 33 */
   HH (d, a, b, c, in[ 8], S32, 0x8771f681); /* 34 */
   HH (c, d, a, b, in[11], S33, 0x6d9d6122); /* 35 */
   HH (b, c, d, a, in[14], S34, 0xfde5380c); /* 36 */
   HH (a, b, c, d, in[ 1], S31, 0xa4beea44); /* 37 */
   HH (d, a, b, c, in[ 4], S32, 0x4bdecfa9); /* 38 */
   HH (c, d, a, b, in[ 7], S33, 0xf6bb4b60); /* 39 */
   HH (b, c, d, a, in[10], S34, 0xbebfbc70); /* 40 */
   HH (a, b, c, d, in[13], S31, 0x289b7ec6); /* 41 */
   HH (d, a, b, c, in[ 0], S32, 0xeaa127fa); /* 42 */
   HH (c, d, a, b, in[ 3], S33, 0xd4ef3085); /* 43 */
   HH (b, c, d, a, in[ 6], S34, 0x4881d05 ); /* 44 */
   HH (a, b, c, d, in[ 9], S31, 0xd9d4d039); /* 45 */
   HH (d, a, b, c, in[12], S32, 0xe6db99e5); /* 46 */
   HH (c, d, a, b, in[15], S33, 0x1fa27cf8); /* 47 */
   HH (b, c, d, a, in[ 2], S34, 0xc4ac5665); /* 48 */

   /* Round 4 */
#define S41 6
#define S42 10
#define S43 15
#define S44 21
   II (a, b, c, d, in[ 0], S41, 0xf4292244); /* 49 */
   II (d, a, b, c, in[ 7], S42, 0x432aff97); /* 50 */
   II (c, d, a, b, in[14], S43, 0xab9423a7); /* 51 */
   II (b, c, d, a, in[ 5], S44, 0xfc93a039); /* 52 */
   II (a, b, c, d, in[12], S41, 0x655b59c3); /* 53 */
   II (d, a, b, c, in[ 3], S42, 0x8f0ccc92); /* 54 */
   II (c, d, a, b, in[10], S43, 0xffeff47d); /* 55 */
   II (b, c, d, a, in[ 1], S44, 0x85845dd1); /* 56 */
   II (a, b, c, d, in[ 8], S41, 0x6fa87e4f); /* 57 */
   II (d, a, b, c, in[15], S42, 0xfe2ce6e0); /* 58 */
   II (c, d, a, b, in[ 6], S43, 0xa3014314); /* 59 */
   II (b, c, d, a, in[13], S44, 0x4e0811a1); /* 60 */
   II (a, b, c, d, in[ 4], S41, 0xf7537e82); /* 61 */
   II (d, a, b, c, in[11], S42, 0xbd3af235); /* 62 */
   II (c, d, a, b, in[ 2], S43, 0x2ad7d2bb); /* 63 */
   II (b, c, d, a, in[ 9], S44, 0xeb86d391); /* 64 */

   buf[0] += a;
   buf[1] += b;
   buf[2] += c;
   buf[3] += d;

   memset((void *)in, 0, sizeof(in));
}

#if 0
int main(int argc, char *argv[])
{
   MD5_CTX md5Context;
   unsigned int len = strlen(argv[1]);
   unsigned char i;

   MD5Init(&md5Context);
   MD5Update(&md5Context, argv[1], len);
   MD5Final(&md5Context);

   printf("MD5sum: ");
   for(i=0;i<16;i++)
      printf("%02x", md5Context.digest[i]);
   printf("\n");

}
#endif