GNU libmicrohttpd  0.9.29
md5.c
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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 "md5.h"
23 
24 
25 #ifndef HIGHFIRST
26 #define byteReverse(buf, len) /* Nothing */
27 #else
28 /*
29  * Note: this code is harmless on little-endian machines.
30  */
31 static void
32 byteReverse(unsigned char *buf,
33  unsigned longs)
34 {
35  uint32_t t;
36  do {
37  t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
38  ((unsigned) buf[1] << 8 | buf[0]);
39  *(uint32_t *) buf = t;
40  buf += 4;
41  } while (--longs);
42 }
43 #endif
44 
45 
46 /* The four core functions - F1 is optimized somewhat */
47 
48 /* #define F1(x, y, z) (x & y | ~x & z) */
49 #define F1(x, y, z) (z ^ (x & (y ^ z)))
50 #define F2(x, y, z) F1(z, x, y)
51 #define F3(x, y, z) (x ^ y ^ z)
52 #define F4(x, y, z) (y ^ (x | ~z))
53 
54 /* This is the central step in the MD5 algorithm. */
55 #define MD5STEP(f, w, x, y, z, data, s) \
56  ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
57 
58 /*
59  * The core of the MD5 algorithm, this alters an existing MD5 hash to
60  * reflect the addition of 16 longwords of new data. MD5Update blocks
61  * the data and converts bytes into longwords for this routine.
62  */
63 static void
64 MD5Transform(uint32_t buf[4],
65  uint32_t in[16])
66 {
67  uint32_t a, b, c, d;
68 
69  a = buf[0];
70  b = buf[1];
71  c = buf[2];
72  d = buf[3];
73 
74  MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
75  MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
76  MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
77  MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
78  MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
79  MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
80  MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
81  MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
82  MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
83  MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
84  MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
85  MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
86  MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
87  MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
88  MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
89  MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
90 
91  MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
92  MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
93  MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
94  MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
95  MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
96  MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
97  MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
98  MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
99  MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
100  MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
101  MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
102  MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
103  MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
104  MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
105  MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
106  MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
107 
108  MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
109  MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
110  MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
111  MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
112  MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
113  MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
114  MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
115  MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
116  MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
117  MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
118  MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
119  MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
120  MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
121  MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
122  MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
123  MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
124 
125  MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
126  MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
127  MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
128  MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
129  MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
130  MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
131  MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
132  MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
133  MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
134  MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
135  MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
136  MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
137  MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
138  MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
139  MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
140  MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
141 
142  buf[0] += a;
143  buf[1] += b;
144  buf[2] += c;
145  buf[3] += d;
146 }
147 
148 
149 /*
150  * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
151  * initialization constants.
152  */
153 void
154 MD5Init(struct MD5Context *ctx)
155 {
156  ctx->buf[0] = 0x67452301;
157  ctx->buf[1] = 0xefcdab89;
158  ctx->buf[2] = 0x98badcfe;
159  ctx->buf[3] = 0x10325476;
160 
161  ctx->bits[0] = 0;
162  ctx->bits[1] = 0;
163 }
164 
165 /*
166  * Update context to reflect the concatenation of another buffer full
167  * of bytes.
168  */
169 void
170 MD5Update(struct MD5Context *ctx,
171  const void *data,
172  unsigned len)
173 {
174  const unsigned char *buf = data;
175  uint32_t t;
176 
177  /* Update bitcount */
178 
179  t = ctx->bits[0];
180  if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
181  ctx->bits[1]++; /* Carry from low to high */
182  ctx->bits[1] += len >> 29;
183 
184  t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
185 
186  /* Handle any leading odd-sized chunks */
187 
188  if (t) {
189  unsigned char *p = (unsigned char *) ctx->in + t;
190 
191  t = 64 - t;
192  if (len < t) {
193  memcpy(p, buf, len);
194  return;
195  }
196  memcpy(p, buf, t);
197  byteReverse(ctx->in, 16);
198  MD5Transform(ctx->buf, (uint32_t *) ctx->in);
199  buf += t;
200  len -= t;
201  }
202  /* Process data in 64-byte chunks */
203 
204  while (len >= 64) {
205  memcpy(ctx->in, buf, 64);
206  byteReverse(ctx->in, 16);
207  MD5Transform(ctx->buf, (uint32_t *) ctx->in);
208  buf += 64;
209  len -= 64;
210  }
211 
212  /* Handle any remaining bytes of data. */
213 
214  memcpy(ctx->in, buf, len);
215 }
216 
217 /*
218  * Final wrapup - pad to 64-byte boundary with the bit pattern
219  * 1 0* (64-bit count of bits processed, MSB-first)
220  */
221 void
222 MD5Final (unsigned char digest[16],
223  struct MD5Context *ctx)
224 {
225  unsigned count;
226  unsigned char *p;
227 
228  /* Compute number of bytes mod 64 */
229  count = (ctx->bits[0] >> 3) & 0x3F;
230 
231  /* Set the first char of padding to 0x80. This is safe since there is
232  always at least one byte free */
233  p = ctx->in + count;
234  *p++ = 0x80;
235 
236  /* Bytes of padding needed to make 64 bytes */
237  count = 64 - 1 - count;
238 
239  /* Pad out to 56 mod 64 */
240  if (count < 8)
241  {
242  /* Two lots of padding: Pad the first block to 64 bytes */
243  memset(p, 0, count);
244  byteReverse(ctx->in, 16);
245  MD5Transform(ctx->buf, (uint32_t *) ctx->in);
246 
247  /* Now fill the next block with 56 bytes */
248  memset(ctx->in, 0, 56);
249  }
250  else
251  {
252  /* Pad block to 56 bytes */
253  memset(p, 0, count - 8);
254  }
255  byteReverse(ctx->in, 14);
256 
257  /* Append length in bits and transform */
258  ((uint32_t *) ctx->in)[14] = ctx->bits[0];
259  ((uint32_t *) ctx->in)[15] = ctx->bits[1];
260 
261  MD5Transform(ctx->buf, (uint32_t *) ctx->in);
262  byteReverse((unsigned char *) ctx->buf, 4);
263  memcpy(digest, ctx->buf, 16);
264  memset(ctx, 0, sizeof(struct MD5Context)); /* In case it's sensitive */
265 }
266 
267 /* end of md5.c */
unsigned char in[64]
Definition: md5.h:36
#define F2(x, y, z)
Definition: md5.c:50
#define byteReverse(buf, len)
Definition: md5.c:26
#define F1(x, y, z)
Definition: md5.c:49
uint32_t buf[4]
Definition: md5.h:34
#define MD5STEP(f, w, x, y, z, data, s)
Definition: md5.c:55
#define F3(x, y, z)
Definition: md5.c:51
static void MD5Transform(uint32_t buf[4], uint32_t in[16])
Definition: md5.c:64
#define F4(x, y, z)
Definition: md5.c:52
void MD5Update(struct MD5Context *ctx, const void *data, unsigned len)
Definition: md5.c:170
void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
Definition: md5.c:222
void MD5Init(struct MD5Context *ctx)
Definition: md5.c:154
uint32_t bits[2]
Definition: md5.h:35
Definition: md5.h:32