The Tor Browser: toolkit/crashreporter/google-breakpad/src/common/md5.cc@b8a032363ba2 (annotated)

toolkit/crashreporter/google-breakpad/src/common/md5.cc@b8a032363ba2 (annotated)

toolkit/crashreporter/google-breakpad/src/common/md5.cc

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

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

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toolkit/crashreporter/google-breakpad/src/common/md5.cc@b8a032363ba2 (annotated)

toolkit/crashreporter/google-breakpad/src/common/md5.cc