/thirdparty/breakpad/common/md5.c

  1/*
  2 * written by Colin Plumb in 1993, no copyright is claimed.
  3 * This code is in the public domain; do with it what you wish.
  4 *
  5 * Equivalent code is available from RSA Data Security, Inc.
  6 * This code has been tested against that, and is equivalent,
  7 * except that you don't need to include two pages of legalese
  8 * with every copy.
  9 *
 10 * To compute the message digest of a chunk of bytes, declare an
 11 * MD5Context structure, pass it to MD5Init, call MD5Update as
 12 * needed on buffers full of bytes, and then call MD5Final, which
 13 * will fill a supplied 16-byte array with the digest.
 14 */
 15
 16#include <string.h>
 17
 18#include "common/md5.h"
 19
 20#ifndef WORDS_BIGENDIAN
 21#define byteReverse(buf, len)   /* Nothing */
 22#else
 23/*
 24 * Note: this code is harmless on little-endian machines.
 25 */
 26static void byteReverse(unsigned char *buf, unsigned longs)
 27{
 28  u32 t;
 29  do {
 30    t = (u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
 31      ((unsigned) buf[1] << 8 | buf[0]);
 32    *(u32 *) buf = t;
 33    buf += 4;
 34  } while (--longs);
 35}
 36#endif
 37
 38static void MD5Transform(u32 buf[4], u32 const in[16]);
 39
 40/*
 41 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 42 * initialization constants.
 43 */
 44void MD5Init(struct MD5Context *ctx)
 45{
 46  ctx->buf[0] = 0x67452301;
 47  ctx->buf[1] = 0xefcdab89;
 48  ctx->buf[2] = 0x98badcfe;
 49  ctx->buf[3] = 0x10325476;
 50
 51  ctx->bits[0] = 0;
 52  ctx->bits[1] = 0;
 53}
 54
 55/*
 56 * Update context to reflect the concatenation of another buffer full
 57 * of bytes.
 58 */
 59void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
 60{
 61  u32 t;
 62
 63  /* Update bitcount */
 64
 65  t = ctx->bits[0];
 66  if ((ctx->bits[0] = t + ((u32) len << 3)) < t)
 67    ctx->bits[1]++;         /* Carry from low to high */
 68  ctx->bits[1] += len >> 29;
 69
 70  t = (t >> 3) & 0x3f;        /* Bytes already in shsInfo->data */
 71
 72  /* Handle any leading odd-sized chunks */
 73
 74  if (t) {
 75    unsigned char *p = (unsigned char *) ctx->in + t;
 76
 77    t = 64 - t;
 78    if (len < t) {
 79      memcpy(p, buf, len);
 80      return;
 81    }
 82    memcpy(p, buf, t);
 83    byteReverse(ctx->in, 16);
 84    MD5Transform(ctx->buf, (u32 *) ctx->in);
 85    buf += t;
 86    len -= t;
 87  }
 88  /* Process data in 64-byte chunks */
 89
 90  while (len >= 64) {
 91    memcpy(ctx->in, buf, 64);
 92    byteReverse(ctx->in, 16);
 93    MD5Transform(ctx->buf, (u32 *) ctx->in);
 94    buf += 64;
 95    len -= 64;
 96  }
 97
 98  /* Handle any remaining bytes of data. */
 99
100  memcpy(ctx->in, buf, len);
101}
102
103/*
104 * Final wrapup - pad to 64-byte boundary with the bit pattern
105 * 1 0* (64-bit count of bits processed, MSB-first)
106 */
107void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
108{
109  unsigned count;
110  unsigned char *p;
111
112  /* Compute number of bytes mod 64 */
113  count = (ctx->bits[0] >> 3) & 0x3F;
114
115  /* Set the first char of padding to 0x80.  This is safe since there is
116     always at least one byte free */
117  p = ctx->in + count;
118  *p++ = 0x80;
119
120  /* Bytes of padding needed to make 64 bytes */
121  count = 64 - 1 - count;
122
123  /* Pad out to 56 mod 64 */
124  if (count < 8) {
125    /* Two lots of padding:  Pad the first block to 64 bytes */
126    memset(p, 0, count);
127    byteReverse(ctx->in, 16);
128    MD5Transform(ctx->buf, (u32 *) ctx->in);
129
130    /* Now fill the next block with 56 bytes */
131    memset(ctx->in, 0, 56);
132  } else {
133    /* Pad block to 56 bytes */
134    memset(p, 0, count - 8);
135  }
136  byteReverse(ctx->in, 14);
137
138  /* Append length in bits and transform */
139  ((u32 *) ctx->in)[14] = ctx->bits[0];
140  ((u32 *) ctx->in)[15] = ctx->bits[1];
141
142  MD5Transform(ctx->buf, (u32 *) ctx->in);
143  byteReverse((unsigned char *) ctx->buf, 4);
144  memcpy(digest, ctx->buf, 16);
145  memset(ctx, 0, sizeof(*ctx));        /* In case it's sensitive */
146}
147
148/* The four core functions - F1 is optimized somewhat */
149
150/* #define F1(x, y, z) (x & y | ~x & z) */
151#define F1(x, y, z) (z ^ (x & (y ^ z)))
152#define F2(x, y, z) F1(z, x, y)
153#define F3(x, y, z) (x ^ y ^ z)
154#define F4(x, y, z) (y ^ (x | ~z))
155
156/* This is the central step in the MD5 algorithm. */
157#define MD5STEP(f, w, x, y, z, data, s) \
158  ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
159
160/*
161 * The core of the MD5 algorithm, this alters an existing MD5 hash to
162 * reflect the addition of 16 longwords of new data.  MD5Update blocks
163 * the data and converts bytes into longwords for this routine.
164 */
165static void MD5Transform(u32 buf[4], u32 const in[16])
166{
167  register u32 a, b, c, d;
168
169  a = buf[0];
170  b = buf[1];
171  c = buf[2];
172  d = buf[3];
173
174  MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
175  MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
176  MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
177  MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
178  MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
179  MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
180  MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
181  MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
182  MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
183  MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
184  MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
185  MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
186  MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
187  MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
188  MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
189  MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
190
191  MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
192  MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
193  MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
194  MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
195  MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
196  MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
197  MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
198  MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
199  MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
200  MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
201  MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
202  MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
203  MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
204  MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
205  MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
206  MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
207
208  MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
209  MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
210  MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
211  MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
212  MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
213  MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
214  MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
215  MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
216  MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
217  MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
218  MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
219  MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
220  MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
221  MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
222  MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
223  MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
224
225  MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
226  MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
227  MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
228  MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
229  MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
230  MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
231  MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
232  MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
233  MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
234  MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
235  MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
236  MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
237  MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
238  MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
239  MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
240  MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
241
242  buf[0] += a;
243  buf[1] += b;
244  buf[2] += c;
245  buf[3] += d;
246}