OpenVAS Libraries  9.0.3
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 /* This code slightly modified to fit into Samba by
19  abartlet@samba.org Jun 2001 */
20 
21 #include <string.h> /* for memmove */
22 #include "md5.h"
23 
24 static void MD5Transform(uint32 buf[4], uint32 const in[16]);
25 
26 /*
27  * Note: this code is harmless on little-endian machines.
28  */
29 static void byteReverse(unsigned char *buf, unsigned longs)
30 {
31  uint32 t;
32  do {
33  t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
34  ((unsigned) buf[1] << 8 | buf[0]);
35  *(uint32 *) buf = t;
36  buf += 4;
37  } while (--longs);
38 }
39 
40 /*
41  * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
42  * initialization constants.
43  */
44 void 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  */
59 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
60 {
61  register uint32 t;
62 
63  /* Update bitcount */
64 
65  t = ctx->bits[0];
66  if ((ctx->bits[0] = t + ((uint32) 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  memmove(p, buf, len);
80  return;
81  }
82  memmove(p, buf, t);
83  byteReverse(ctx->in, 16);
84  MD5Transform(ctx->buf, (uint32 *) ctx->in);
85  buf += t;
86  len -= t;
87  }
88  /* Process data in 64-byte chunks */
89 
90  while (len >= 64) {
91  memmove(ctx->in, buf, 64);
92  byteReverse(ctx->in, 16);
93  MD5Transform(ctx->buf, (uint32 *) ctx->in);
94  buf += 64;
95  len -= 64;
96  }
97 
98  /* Handle any remaining bytes of data. */
99 
100  memmove(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  */
107 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
108 {
109  unsigned int 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, (uint32 *) 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  ((uint32 *) ctx->in)[14] = ctx->bits[0];
140  ((uint32 *) ctx->in)[15] = ctx->bits[1];
141 
142  MD5Transform(ctx->buf, (uint32 *) ctx->in);
143  byteReverse((unsigned char *) ctx->buf, 4);
144  memmove(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  */
165 static void MD5Transform(uint32 buf[4], uint32 const in[16])
166 {
167  register uint32 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 }
#define uint32
Definition: genrand.c:49
unsigned char in[64]
Definition: md5.h:49
#define F2(x, y, z)
Definition: md5.c:152
#define F1(x, y, z)
Definition: md5.c:151
uint32 buf[4]
Definition: md5.h:47
uint32 bits[2]
Definition: md5.h:48
#define MD5STEP(f, w, x, y, z, data, s)
Definition: md5.c:157
#define F3(x, y, z)
Definition: md5.c:153
#define F4(x, y, z)
Definition: md5.c:154
void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
Definition: md5.c:107
void MD5Init(struct MD5Context *ctx)
Definition: md5.c:44
Definition: md5.h:46
void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
Definition: md5.c:59