GNU libmicrohttpd  0.9.66
md5.c
Go to the documentation of this file.
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 MHD_MD5Init, call MHD_MD5Update as
14  * needed on buffers full of bytes, and then call MHD_MD5Final, which
15  * will fill a supplied 16-byte array with the digest.
16  */
17 
18 /* Based on OpenBSD modifications.
19  * Optimized by Karlson2k (Evgeny Grin). */
20 
21 #include "md5.h"
22 #include <string.h>
23 #ifdef HAVE_MEMORY_H
24 #include <memory.h>
25 #endif /* HAVE_MEMORY_H */
26 #include "mhd_bithelpers.h"
27 #include "mhd_assert.h"
28 
29 
36 void
37 MHD_MD5Init (void *ctx_)
38 {
39  struct MD5Context *ctx = ctx_;
40 
41  mhd_assert (ctx != NULL);
42  ctx->count = 0;
43  ctx->state[0] = 0x67452301;
44  ctx->state[1] = 0xefcdab89;
45  ctx->state[2] = 0x98badcfe;
46  ctx->state[3] = 0x10325476;
47 }
48 
49 static void
50 MD5Transform (uint32_t state[4],
51  const uint8_t block[MD5_BLOCK_SIZE]);
52 
53 
59 void
60 MHD_MD5Final (void *ctx_,
61  uint8_t digest[MD5_DIGEST_SIZE])
62 {
63  struct MD5Context *ctx = ctx_;
64  uint64_t count_bits;
65  size_t have_bytes;
66 
67  mhd_assert (ctx != NULL);
68  mhd_assert (digest != NULL);
69 
70  /* Convert count to 8 bytes in little endian order. */
71  have_bytes = (ctx->count) & (MD5_BLOCK_SIZE - 1);
72 
73  /* Pad data */
74  /* Buffer always have space for one byte or more. */
75  ctx->buffer[have_bytes++] = 0x80; /* First padding byte is 0x80 */
76 
77  if (MD5_BLOCK_SIZE - have_bytes < 8)
78  { /* Not enough space to put number of bits */
79  while (have_bytes < MD5_BLOCK_SIZE) ctx->buffer[have_bytes++] = 0;
80  MD5Transform(ctx->state, ctx->buffer);
81  have_bytes = 0; /* Additional block */
82  }
83  /* Pad out to 56 */
84  memset(ctx->buffer + have_bytes, 0, MD5_BLOCK_SIZE - have_bytes - 8);
85 
86  /* Put number of bits */
87  count_bits = ctx->count << 3;
88  _MHD_PUT_64BIT_LE(ctx->buffer + 56, count_bits);
89  MD5Transform(ctx->state, ctx->buffer);
90 
91  /* Put digest in LE mode */
92  _MHD_PUT_32BIT_LE(digest, ctx->state[0]);
93  _MHD_PUT_32BIT_LE(digest + 4, ctx->state[1]);
94  _MHD_PUT_32BIT_LE(digest + 8, ctx->state[2]);
95  _MHD_PUT_32BIT_LE(digest + 12, ctx->state[3]);
96 
97  /* Erase buffer */
98  memset(ctx, 0, sizeof(*ctx));
99 }
100 
101 
106 #define MD5_BYTES_IN_WORD (32 / 8)
107 
108 /* The four core functions - F1 is optimized somewhat */
109 
110 /* #define F1(x, y, z) (x & y | ~x & z) */
111 #define F1(x, y, z) (z ^ (x & (y ^ z)))
112 #define F2(x, y, z) F1(z, x, y)
113 #define F3(x, y, z) (x ^ y ^ z)
114 #define F4(x, y, z) (y ^ (x | ~z))
115 
116 /* This is the central step in the MD5 algorithm. */
117 #define MD5STEP(f, w, x, y, z, data, s) \
118  ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
119 
125 static void
126 MD5Transform (uint32_t state[4],
127  const uint8_t block[MD5_BLOCK_SIZE])
128 {
129  uint32_t a, b, c, d;
130 
131 #if _MHD_BYTE_ORDER == _MHD_LITTLE_ENDIAN
132  const uint32_t *in = (const uint32_t *)block;
133 #else
134  uint32_t in[MD5_BLOCK_SIZE / MD5_BYTES_IN_WORD];
135  int i;
136 
137  for (i = 0; i < MD5_BLOCK_SIZE / MD5_BYTES_IN_WORD; i++)
138  {
139  in[i] = _MHD_GET_32BIT_LE(block + i * MD5_BYTES_IN_WORD);
140  }
141 #endif
142 
143  a = state[0];
144  b = state[1];
145  c = state[2];
146  d = state[3];
147 
148  MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
149  MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
150  MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
151  MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
152  MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
153  MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
154  MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
155  MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
156  MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
157  MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
158  MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
159  MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
160  MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
161  MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
162  MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
163  MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
164 
165  MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
166  MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
167  MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
168  MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
169  MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
170  MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
171  MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
172  MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
173  MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
174  MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
175  MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
176  MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
177  MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
178  MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
179  MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
180  MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
181 
182  MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
183  MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
184  MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
185  MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
186  MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
187  MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
188  MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
189  MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
190  MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
191  MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
192  MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
193  MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
194  MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
195  MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
196  MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
197  MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
198 
199  MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
200  MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
201  MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
202  MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
203  MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
204  MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
205  MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
206  MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
207  MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
208  MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
209  MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
210  MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
211  MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
212  MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
213  MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
214  MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
215 
216  state[0] += a;
217  state[1] += b;
218  state[2] += c;
219  state[3] += d;
220 }
221 
222 
227 void
228 MHD_MD5Update (void *ctx_,
229  const uint8_t *input,
230  size_t len)
231 {
232  struct MD5Context *ctx = ctx_;
233  size_t have, need;
234 
235  mhd_assert (ctx != NULL);
236  mhd_assert ((ctx != NULL) || (len == 0));
237 
238  /* Check how many bytes we already have and how many more we need. */
239  have = (size_t)((ctx->count) & (MD5_BLOCK_SIZE - 1));
240  need = MD5_BLOCK_SIZE - have;
241 
242  /* Update bytecount */
243  ctx->count += (uint64_t)len;
244 
245  if (len >= need)
246  {
247  if (have != 0)
248  {
249  memcpy (ctx->buffer + have,
250  input,
251  need);
252  MD5Transform(ctx->state, ctx->buffer);
253  input += need;
254  len -= need;
255  have = 0;
256  }
257 
258  /* Process data in MD5_BLOCK_SIZE-byte chunks. */
259  while (len >= MD5_BLOCK_SIZE)
260  {
261  MD5Transform (ctx->state,
262  (const unsigned char *) input);
263  input += MD5_BLOCK_SIZE;
264  len -= MD5_BLOCK_SIZE;
265  }
266  }
267 
268  /* Handle any remaining bytes of data. */
269  if (0 != len)
270  memcpy (ctx->buffer + have,
271  input,
272  len);
273 }
274 
275 
276 /* end of md5.c */
#define _MHD_PUT_32BIT_LE(addr, value32)
#define F2(x, y, z)
Definition: md5.c:112
#define F1(x, y, z)
Definition: md5.c:111
uint8_t buffer[MD5_BLOCK_SIZE]
Definition: md5.h:33
void MHD_MD5Final(void *ctx_, uint8_t digest[MD5_DIGEST_SIZE])
Definition: md5.c:60
uint64_t count
Definition: md5.h:32
void MHD_MD5Init(void *ctx_)
Definition: md5.c:37
#define MD5_BYTES_IN_WORD
Definition: md5.c:106
#define MD5STEP(f, w, x, y, z, data, s)
Definition: md5.c:117
macros for mhd_assert()
#define F3(x, y, z)
Definition: md5.c:113
#define NULL
Definition: reason_phrase.c:30
void MHD_MD5Update(void *ctx_, const uint8_t *input, size_t len)
Definition: md5.c:228
#define F4(x, y, z)
Definition: md5.c:114
#define MD5_BLOCK_SIZE
Definition: md5.h:25
#define mhd_assert(CHK)
Definition: mhd_assert.h:39
Definition: md5.h:29
#define _MHD_GET_32BIT_LE(addr)
#define MD5_DIGEST_SIZE
Definition: md5.h:26
static void MD5Transform(uint32_t state[4], const uint8_t block[MD5_BLOCK_SIZE])
Definition: md5.c:126
uint32_t state[4]
Definition: md5.h:31
#define _MHD_PUT_64BIT_LE(addr, value64)
macros for bits manipulations