Wed Jan 8 2020 09:49:48

Asterisk developer's documentation


md5.c
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1 
2 /*!\file
3 \brief MD5 checksum routines used for authentication. Not covered by GPL, but
4  in the public domain as per the copyright below */
5 
6 /*
7  * This code implements the MD5 message-digest algorithm.
8  * The algorithm is due to Ron Rivest. This code was
9  * written by Colin Plumb in 1993, no copyright is claimed.
10  * This code is in the public domain; do with it what you wish.
11  *
12  * Equivalent code is available from RSA Data Security, Inc.
13  * This code has been tested against that, and is equivalent,
14  * except that you don't need to include two pages of legalese
15  * with every copy.
16  *
17  * To compute the message digest of a chunk of bytes, declare an
18  * MD5Context structure, pass it to MD5Init, call MD5Update as
19  * needed on buffers full of bytes, and then call MD5Final, which
20  * will fill a supplied 16-byte array with the digest.
21  */
22 
23 #include "asterisk.h"
24 
25 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 368719 $")
26 
27 #include "asterisk/endian.h"
28 #include "asterisk/md5.h"
29 
30 # if __BYTE_ORDER == __BIG_ENDIAN
31 # define HIGHFIRST 1
32 # endif
33 #ifndef HIGHFIRST
34 #define byteReverse(buf, len) /* Nothing */
35 #else
36 void byteReverse(unsigned char *buf, unsigned longs);
37 
38 #ifndef ASM_MD5
39 /*
40  * Note: this code is harmless on little-endian machines.
41  */
42 void byteReverse(unsigned char *buf, unsigned longs)
43 {
44  uint32_t t;
45  do {
46  t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
47  ((unsigned) buf[1] << 8 | buf[0]);
48  *(uint32_t *) buf = t;
49  buf += 4;
50  } while (--longs);
51 }
52 #endif
53 #endif
54 
55 /*
56  * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
57  * initialization constants.
58  */
59 void MD5Init(struct MD5Context *ctx)
60 {
61  ctx->buf[0] = 0x67452301;
62  ctx->buf[1] = 0xefcdab89;
63  ctx->buf[2] = 0x98badcfe;
64  ctx->buf[3] = 0x10325476;
65 
66  ctx->bits[0] = 0;
67  ctx->bits[1] = 0;
68 }
69 
70 /*
71  * Update context to reflect the concatenation of another buffer full
72  * of bytes.
73  */
74 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
75 {
76  uint32_t t;
77 
78  /* Update bitcount */
79 
80  t = ctx->bits[0];
81  if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
82  ctx->bits[1]++; /* Carry from low to high */
83  ctx->bits[1] += len >> 29;
84 
85  t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
86 
87  /* Handle any leading odd-sized chunks */
88 
89  if (t) {
90  unsigned char *p = (unsigned char *) ctx->in + t;
91 
92  t = 64 - t;
93  if (len < t) {
94  memcpy(p, buf, len);
95  return;
96  }
97  memcpy(p, buf, t);
98  byteReverse(ctx->in, 16);
99  MD5Transform(ctx->buf, (uint32_t *) ctx->in);
100  buf += t;
101  len -= t;
102  }
103  /* Process data in 64-byte chunks */
104 
105  while (len >= 64) {
106  memcpy(ctx->in, buf, 64);
107  byteReverse(ctx->in, 16);
108  MD5Transform(ctx->buf, (uint32_t *) ctx->in);
109  buf += 64;
110  len -= 64;
111  }
112 
113  /* Handle any remaining bytes of data. */
114 
115  memcpy(ctx->in, buf, len);
116 }
117 
118 /*
119  * Final wrapup - pad to 64-byte boundary with the bit pattern
120  * 1 0* (64-bit count of bits processed, MSB-first)
121  */
122 void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
123 {
124  unsigned count;
125  unsigned char *p;
126  uint32_t *in_buf;
127 
128  /* Compute number of bytes mod 64 */
129  count = (ctx->bits[0] >> 3) & 0x3F;
130 
131  /* Set the first char of padding to 0x80. This is safe since there is
132  always at least one byte free */
133  p = ctx->in + count;
134  *p++ = 0x80;
135 
136  /* Bytes of padding needed to make 64 bytes */
137  count = 64 - 1 - count;
138 
139  /* Pad out to 56 mod 64 */
140  if (count < 8) {
141  /* Two lots of padding: Pad the first block to 64 bytes */
142  memset(p, 0, count);
143  byteReverse(ctx->in, 16);
144  MD5Transform(ctx->buf, (uint32_t *) ctx->in);
145 
146  /* Now fill the next block with 56 bytes */
147  memset(ctx->in, 0, 56);
148  } else {
149  /* Pad block to 56 bytes */
150  memset(p, 0, count - 8);
151  }
152  byteReverse(ctx->in, 14);
153 
154  /* Append length in bits and transform */
155  in_buf = (uint32_t *) ctx->in;
156  in_buf[14] = ctx->bits[0];
157  in_buf[15] = ctx->bits[1];
158 
159  MD5Transform(ctx->buf, (uint32_t *) ctx->in);
160  byteReverse((unsigned char *) ctx->buf, 4);
161  memcpy(digest, ctx->buf, 16);
162  memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
163 }
164 
165 #ifndef ASM_MD5
166 
167 /* The four core functions - F1 is optimized somewhat */
168 
169 /* #define F1(x, y, z) (x & y | ~x & z) */
170 #define F1(x, y, z) (z ^ (x & (y ^ z)))
171 #define F2(x, y, z) F1(z, x, y)
172 #define F3(x, y, z) (x ^ y ^ z)
173 #define F4(x, y, z) (y ^ (x | ~z))
174 
175 /* This is the central step in the MD5 algorithm. */
176 #define MD5STEP(f, w, x, y, z, data, s) \
177  ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
178 
179 /*
180  * The core of the MD5 algorithm, this alters an existing MD5 hash to
181  * reflect the addition of 16 longwords of new data. MD5Update blocks
182  * the data and converts bytes into longwords for this routine.
183  */
184 void MD5Transform(uint32_t buf[4], uint32_t const in[16])
185 {
186  register uint32_t a, b, c, d;
187 
188  a = buf[0];
189  b = buf[1];
190  c = buf[2];
191  d = buf[3];
192 
193  MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
194  MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
195  MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
196  MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
197  MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
198  MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
199  MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
200  MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
201  MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
202  MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
203  MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
204  MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
205  MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
206  MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
207  MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
208  MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
209 
210  MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
211  MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
212  MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
213  MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
214  MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
215  MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
216  MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
217  MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
218  MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
219  MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
220  MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
221  MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
222  MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
223  MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
224  MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
225  MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
226 
227  MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
228  MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
229  MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
230  MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
231  MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
232  MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
233  MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
234  MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
235  MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
236  MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
237  MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
238  MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
239  MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
240  MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
241  MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
242  MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
243 
244  MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
245  MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
246  MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
247  MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
248  MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
249  MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
250  MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
251  MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
252  MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
253  MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
254  MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
255  MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
256  MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
257  MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
258  MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
259  MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
260 
261  buf[0] += a;
262  buf[1] += b;
263  buf[2] += c;
264  buf[3] += d;
265 }
266 
267 #endif
Asterisk main include file. File version handling, generic pbx functions.
#define F2(x, y, z)
Definition: md5.c:171
void MD5Transform(uint32_t buf[4], uint32_t const in[16])
Definition: md5.c:184
#define byteReverse(buf, len)
Definition: md5.c:34
uint32_t bits[2]
Definition: md5.h:28
#define F1(x, y, z)
Definition: md5.c:170
void MD5Final(unsigned char digest[16], struct MD5Context *context)
Definition: md5.c:122
unsigned char in[64]
Definition: md5.h:29
void MD5Init(struct MD5Context *context)
Definition: md5.c:59
#define MD5STEP(f, w, x, y, z, data, s)
Definition: md5.c:176
#define F3(x, y, z)
Definition: md5.c:172
void MD5Update(struct MD5Context *context, unsigned char const *buf, unsigned len)
Definition: md5.c:74
#define F4(x, y, z)
Definition: md5.c:173
static int len(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t buflen)
if(yyss+yystacksize-1<=yyssp)
Definition: ast_expr2.c:1874
Definition: md5.h:26
uint32_t buf[4]
Definition: md5.h:27
MD5 digest functions.
#define ASTERISK_FILE_VERSION(file, version)
Register/unregister a source code file with the core.
Definition: asterisk.h:180