michael@0: /*
michael@0:  * written by Colin Plumb in 1993, no copyright is claimed.
michael@0:  * This code is in the public domain; do with it what you wish.
michael@0:  *
michael@0:  * Equivalent code is available from RSA Data Security, Inc.
michael@0:  * This code has been tested against that, and is equivalent,
michael@0:  * except that you don't need to include two pages of legalese
michael@0:  * with every copy.
michael@0:  *
michael@0:  * To compute the message digest of a chunk of bytes, declare an
michael@0:  * MD5Context structure, pass it to MD5Init, call MD5Update as
michael@0:  * needed on buffers full of bytes, and then call MD5Final, which
michael@0:  * will fill a supplied 16-byte array with the digest.
michael@0:  */
michael@0: 
michael@0: #include <string.h>
michael@0: 
michael@0: #include "common/md5.h"
michael@0: 
michael@0: namespace google_breakpad {
michael@0: 
michael@0: #ifndef WORDS_BIGENDIAN
michael@0: #define byteReverse(buf, len)   /* Nothing */
michael@0: #else
michael@0: /*
michael@0:  * Note: this code is harmless on little-endian machines.
michael@0:  */
michael@0: static void byteReverse(unsigned char *buf, unsigned longs)
michael@0: {
michael@0:   u32 t;
michael@0:   do {
michael@0:     t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
michael@0:       ((unsigned) buf[1] << 8 | buf[0]);
michael@0:     *(u32 *) buf = t;
michael@0:     buf += 4;
michael@0:   } while (--longs);
michael@0: }
michael@0: #endif
michael@0: 
michael@0: static void MD5Transform(u32 buf[4], u32 const in[16]);
michael@0: 
michael@0: /*
michael@0:  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
michael@0:  * initialization constants.
michael@0:  */
michael@0: void MD5Init(struct MD5Context *ctx)
michael@0: {
michael@0:   ctx->buf[0] = 0x67452301;
michael@0:   ctx->buf[1] = 0xefcdab89;
michael@0:   ctx->buf[2] = 0x98badcfe;
michael@0:   ctx->buf[3] = 0x10325476;
michael@0: 
michael@0:   ctx->bits[0] = 0;
michael@0:   ctx->bits[1] = 0;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * Update context to reflect the concatenation of another buffer full
michael@0:  * of bytes.
michael@0:  */
michael@0: void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
michael@0: {
michael@0:   u32 t;
michael@0: 
michael@0:   /* Update bitcount */
michael@0: 
michael@0:   t = ctx->bits[0];
michael@0:   if ((ctx->bits[0] = t + ((u32) len << 3)) < t)
michael@0:     ctx->bits[1]++;         /* Carry from low to high */
michael@0:   ctx->bits[1] += len >> 29;
michael@0: 
michael@0:   t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
michael@0: 
michael@0:   /* Handle any leading odd-sized chunks */
michael@0: 
michael@0:   if (t) {
michael@0:     unsigned char *p = (unsigned char *) ctx->in + t;
michael@0: 
michael@0:     t = 64 - t;
michael@0:     if (len < t) {
michael@0:       memcpy(p, buf, len);
michael@0:       return;
michael@0:     }
michael@0:     memcpy(p, buf, t);
michael@0:     byteReverse(ctx->in, 16);
michael@0:     MD5Transform(ctx->buf, (u32 *) ctx->in);
michael@0:     buf += t;
michael@0:     len -= t;
michael@0:   }
michael@0:   /* Process data in 64-byte chunks */
michael@0: 
michael@0:   while (len >= 64) {
michael@0:     memcpy(ctx->in, buf, 64);
michael@0:     byteReverse(ctx->in, 16);
michael@0:     MD5Transform(ctx->buf, (u32 *) ctx->in);
michael@0:     buf += 64;
michael@0:     len -= 64;
michael@0:   }
michael@0: 
michael@0:   /* Handle any remaining bytes of data. */
michael@0: 
michael@0:   memcpy(ctx->in, buf, len);
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * Final wrapup - pad to 64-byte boundary with the bit pattern
michael@0:  * 1 0* (64-bit count of bits processed, MSB-first)
michael@0:  */
michael@0: void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
michael@0: {
michael@0:   unsigned count;
michael@0:   unsigned char *p;
michael@0: 
michael@0:   /* Compute number of bytes mod 64 */
michael@0:   count = (ctx->bits[0] >> 3) & 0x3F;
michael@0: 
michael@0:   /* Set the first char of padding to 0x80.  This is safe since there is
michael@0:      always at least one byte free */
michael@0:   p = ctx->in + count;
michael@0:   *p++ = 0x80;
michael@0: 
michael@0:   /* Bytes of padding needed to make 64 bytes */
michael@0:   count = 64 - 1 - count;
michael@0: 
michael@0:   /* Pad out to 56 mod 64 */
michael@0:   if (count < 8) {
michael@0:     /* Two lots of padding:  Pad the first block to 64 bytes */
michael@0:     memset(p, 0, count);
michael@0:     byteReverse(ctx->in, 16);
michael@0:     MD5Transform(ctx->buf, (u32 *) ctx->in);
michael@0: 
michael@0:     /* Now fill the next block with 56 bytes */
michael@0:     memset(ctx->in, 0, 56);
michael@0:   } else {
michael@0:     /* Pad block to 56 bytes */
michael@0:     memset(p, 0, count - 8);
michael@0:   }
michael@0:   byteReverse(ctx->in, 14);
michael@0: 
michael@0:   /* Append length in bits and transform */
michael@0:   ((u32 *) ctx->in)[14] = ctx->bits[0];
michael@0:   ((u32 *) ctx->in)[15] = ctx->bits[1];
michael@0: 
michael@0:   MD5Transform(ctx->buf, (u32 *) ctx->in);
michael@0:   byteReverse((unsigned char *) ctx->buf, 4);
michael@0:   memcpy(digest, ctx->buf, 16);
michael@0:   memset(ctx, 0, sizeof(*ctx));        /* In case it's sensitive */
michael@0: }
michael@0: 
michael@0: /* The four core functions - F1 is optimized somewhat */
michael@0: 
michael@0: /* #define F1(x, y, z) (x & y | ~x & z) */
michael@0: #define F1(x, y, z) (z ^ (x & (y ^ z)))
michael@0: #define F2(x, y, z) F1(z, x, y)
michael@0: #define F3(x, y, z) (x ^ y ^ z)
michael@0: #define F4(x, y, z) (y ^ (x | ~z))
michael@0: 
michael@0: /* This is the central step in the MD5 algorithm. */
michael@0: #define MD5STEP(f, w, x, y, z, data, s) \
michael@0:   ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
michael@0: 
michael@0: /*
michael@0:  * The core of the MD5 algorithm, this alters an existing MD5 hash to
michael@0:  * reflect the addition of 16 longwords of new data.  MD5Update blocks
michael@0:  * the data and converts bytes into longwords for this routine.
michael@0:  */
michael@0: static void MD5Transform(u32 buf[4], u32 const in[16])
michael@0: {
michael@0:   register u32 a, b, c, d;
michael@0: 
michael@0:   a = buf[0];
michael@0:   b = buf[1];
michael@0:   c = buf[2];
michael@0:   d = buf[3];
michael@0: 
michael@0:   MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
michael@0:   MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
michael@0:   MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
michael@0:   MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
michael@0:   MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
michael@0:   MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
michael@0:   MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
michael@0:   MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
michael@0:   MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
michael@0:   MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
michael@0:   MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
michael@0:   MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
michael@0:   MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
michael@0:   MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
michael@0:   MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
michael@0:   MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
michael@0: 
michael@0:   MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
michael@0:   MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
michael@0:   MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
michael@0:   MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
michael@0:   MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
michael@0:   MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
michael@0:   MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
michael@0:   MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
michael@0:   MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
michael@0:   MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
michael@0:   MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
michael@0:   MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
michael@0:   MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
michael@0:   MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
michael@0:   MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
michael@0:   MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
michael@0: 
michael@0:   MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
michael@0:   MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
michael@0:   MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
michael@0:   MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
michael@0:   MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
michael@0:   MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
michael@0:   MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
michael@0:   MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
michael@0:   MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
michael@0:   MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
michael@0:   MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
michael@0:   MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
michael@0:   MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
michael@0:   MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
michael@0:   MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
michael@0:   MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
michael@0: 
michael@0:   MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
michael@0:   MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
michael@0:   MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
michael@0:   MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
michael@0:   MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
michael@0:   MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
michael@0:   MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
michael@0:   MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
michael@0:   MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
michael@0:   MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
michael@0:   MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
michael@0:   MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
michael@0:   MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
michael@0:   MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
michael@0:   MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
michael@0:   MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
michael@0: 
michael@0:   buf[0] += a;
michael@0:   buf[1] += b;
michael@0:   buf[2] += c;
michael@0:   buf[3] += d;
michael@0: }
michael@0: 
michael@0: }  // namespace google_breakpad
michael@0: