1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
2 /*
3 * This code implements the MD5 message-digest algorithm.
4 * The algorithm is due to Ron Rivest. This code was
5 * written by Colin Plumb in 1993, no copyright is claimed.
6 * This code is in the public domain; do with it what you wish.
7 *
8 * Equivalent code is available from RSA Data Security, Inc.
9 * This code has been tested against that, and is equivalent,
10 * except that you don't need to include two pages of legalese
11 * with every copy.
12 *
13 * To compute the message digest of a chunk of bytes, declare an
14 * MD5Context structure, pass it to md5_init, call md5_update as
15 * needed on buffers full of bytes, and then call md5_Final, which
16 * will fill a supplied 16-byte array with the digest.
17 */
18
19 /* parts of this file are:
20 * Written March 1993 by Branko Lankester
21 * Modified June 1993 by Colin Plumb for altered md5.c.
22 * Modified October 1995 by Erik Troan for RPM
23 */
24
25
26 #ifdef HAVE_CONFIG_H
27 #include <config.h>
28 #endif
29
30 #include <stdio.h>
31 #include <string.h>
32 #include <sys/types.h>
33 #include "md5-utils.h"
34
35 #define d(x)
36
37 static void md5_transform (guint32 buf[4], const guint32 in[16]);
38
39 static int _ie = 0x44332211;
40 static union _endian { int i; char b[4]; } *_endian = (union _endian *) &_ie;
41 #define IS_BIG_ENDIAN() (_endian->b[0] == '\x44')
42 #define IS_LITTLE_ENDIAN() (_endian->b[0] == '\x11')
43
44
45 /*
46 * Note: this code is harmless on little-endian machines.
47 */
48 static void
_byte_reverse(unsigned char * buf,guint32 longs)49 _byte_reverse (unsigned char *buf, guint32 longs)
50 {
51 guint32 t;
52
53 do {
54 t = (guint32) ((guint32) buf[3] << 8 | buf[2]) << 16 |
55 ((guint32) buf[1] << 8 | buf[0]);
56 *(guint32 *) buf = t;
57 buf += 4;
58 } while (--longs);
59 }
60
61
62 /**
63 * md5_init: Initialise an md5 context object
64 * @ctx: md5 context
65 *
66 * Initialise an md5 buffer.
67 *
68 **/
69 void
md5_init(MD5Context * ctx)70 md5_init (MD5Context *ctx)
71 {
72 ctx->buf[0] = 0x67452301;
73 ctx->buf[1] = 0xefcdab89;
74 ctx->buf[2] = 0x98badcfe;
75 ctx->buf[3] = 0x10325476;
76
77 ctx->bits[0] = 0;
78 ctx->bits[1] = 0;
79
80 if (IS_BIG_ENDIAN ())
81 ctx->doByteReverse = 1;
82 else
83 ctx->doByteReverse = 0;
84 }
85
86
87 /**
88 * md5_update: add a buffer to md5 hash computation
89 * @ctx: conetxt object used for md5 computaion
90 * @buf: buffer to add
91 * @len: buffer length
92 *
93 * Update context to reflect the concatenation of another buffer full
94 * of bytes. Use this to progressively construct an md5 hash.
95 **/
96 void
md5_update(MD5Context * ctx,const unsigned char * buf,guint32 len)97 md5_update (MD5Context *ctx, const unsigned char *buf, guint32 len)
98 {
99 guint32 t;
100
101 /* Update bitcount */
102 t = ctx->bits[0];
103 if ((ctx->bits[0] = t + ((guint32) len << 3)) < t)
104 ctx->bits[1]++; /* Carry from low to high */
105 ctx->bits[1] += len >> 29;
106
107 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
108
109 /* Handle any leading odd-sized chunks */
110 if (t) {
111 unsigned char *p = (unsigned char *) ctx->in + t;
112
113 t = 64 - t;
114 if (len < t) {
115 memcpy (p, buf, len);
116 return;
117 }
118 memcpy (p, buf, t);
119 if (ctx->doByteReverse)
120 _byte_reverse (ctx->in, 16);
121 md5_transform (ctx->buf, (guint32 *) ctx->in);
122 buf += t;
123 len -= t;
124 }
125
126 /* Process data in 64-byte chunks */
127 while (len >= 64) {
128 memcpy (ctx->in, buf, 64);
129 if (ctx->doByteReverse)
130 _byte_reverse (ctx->in, 16);
131 md5_transform (ctx->buf, (guint32 *) ctx->in);
132 buf += 64;
133 len -= 64;
134 }
135
136 /* Handle any remaining bytes of data. */
137 memcpy (ctx->in, buf, len);
138 }
139
140
141 /*
142 * Final wrapup - pad to 64-byte boundary with the bit pattern
143 * 1 0* (64-bit count of bits processed, MSB-first)
144 */
145 /**
146 * md5_final: copy the final md5 hash to a bufer
147 * @digest: 16 bytes buffer
148 * @ctx: context containing the calculated md5
149 *
150 * copy the final md5 hash to a bufer
151 **/
152 void
md5_final(MD5Context * ctx,unsigned char digest[16])153 md5_final (MD5Context *ctx, unsigned char digest[16])
154 {
155 guint32 count;
156 unsigned char *p;
157
158 /* Compute number of bytes mod 64 */
159 count = (ctx->bits[0] >> 3) & 0x3F;
160
161 /* Set the first char of padding to 0x80. This is safe since there is
162 always at least one byte free */
163 p = ctx->in + count;
164 *p++ = 0x80;
165
166 /* Bytes of padding needed to make 64 bytes */
167 count = 64 - 1 - count;
168
169 /* Pad out to 56 mod 64 */
170 if (count < 8) {
171 /* Two lots of padding: Pad the first block to 64 bytes */
172 memset (p, 0, count);
173 if (ctx->doByteReverse)
174 _byte_reverse (ctx->in, 16);
175 md5_transform (ctx->buf, (guint32 *) ctx->in);
176
177 /* Now fill the next block with 56 bytes */
178 memset (ctx->in, 0, 56);
179 } else {
180 /* Pad block to 56 bytes */
181 memset (p, 0, count - 8);
182 }
183
184 if (ctx->doByteReverse)
185 _byte_reverse (ctx->in, 14);
186
187 /* Append length in bits and transform */
188 ((guint32 *) ctx->in)[14] = ctx->bits[0];
189 ((guint32 *) ctx->in)[15] = ctx->bits[1];
190
191 md5_transform (ctx->buf, (guint32 *) ctx->in);
192 if (ctx->doByteReverse)
193 _byte_reverse ((unsigned char *) ctx->buf, 4);
194 memcpy (digest, ctx->buf, 16);
195 }
196
197
198 /* The four core functions - F1 is optimized somewhat */
199
200 /* #define F1(x, y, z) (x & y | ~x & z) */
201 #define F1(x, y, z) (z ^ (x & (y ^ z)))
202 #define F2(x, y, z) F1(z, x, y)
203 #define F3(x, y, z) (x ^ y ^ z)
204 #define F4(x, y, z) (y ^ (x | ~z))
205
206 /* This is the central step in the MD5 algorithm. */
207 #define MD5STEP(f, w, x, y, z, data, s) \
208 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
209
210 /*
211 * The core of the MD5 algorithm, this alters an existing MD5 hash to
212 * reflect the addition of 16 longwords of new data. md5_Update blocks
213 * the data and converts bytes into longwords for this routine.
214 */
215 static void
md5_transform(guint32 buf[4],const guint32 in[16])216 md5_transform (guint32 buf[4], const guint32 in[16])
217 {
218 register guint32 a, b, c, d;
219
220 a = buf[0];
221 b = buf[1];
222 c = buf[2];
223 d = buf[3];
224
225 MD5STEP (F1, a, b, c, d, in[0] + 0xd76aa478, 7);
226 MD5STEP (F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
227 MD5STEP (F1, c, d, a, b, in[2] + 0x242070db, 17);
228 MD5STEP (F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
229 MD5STEP (F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
230 MD5STEP (F1, d, a, b, c, in[5] + 0x4787c62a, 12);
231 MD5STEP (F1, c, d, a, b, in[6] + 0xa8304613, 17);
232 MD5STEP (F1, b, c, d, a, in[7] + 0xfd469501, 22);
233 MD5STEP (F1, a, b, c, d, in[8] + 0x698098d8, 7);
234 MD5STEP (F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
235 MD5STEP (F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
236 MD5STEP (F1, b, c, d, a, in[11] + 0x895cd7be, 22);
237 MD5STEP (F1, a, b, c, d, in[12] + 0x6b901122, 7);
238 MD5STEP (F1, d, a, b, c, in[13] + 0xfd987193, 12);
239 MD5STEP (F1, c, d, a, b, in[14] + 0xa679438e, 17);
240 MD5STEP (F1, b, c, d, a, in[15] + 0x49b40821, 22);
241
242 MD5STEP (F2, a, b, c, d, in[1] + 0xf61e2562, 5);
243 MD5STEP (F2, d, a, b, c, in[6] + 0xc040b340, 9);
244 MD5STEP (F2, c, d, a, b, in[11] + 0x265e5a51, 14);
245 MD5STEP (F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
246 MD5STEP (F2, a, b, c, d, in[5] + 0xd62f105d, 5);
247 MD5STEP (F2, d, a, b, c, in[10] + 0x02441453, 9);
248 MD5STEP (F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
249 MD5STEP (F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
250 MD5STEP (F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
251 MD5STEP (F2, d, a, b, c, in[14] + 0xc33707d6, 9);
252 MD5STEP (F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
253 MD5STEP (F2, b, c, d, a, in[8] + 0x455a14ed, 20);
254 MD5STEP (F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
255 MD5STEP (F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
256 MD5STEP (F2, c, d, a, b, in[7] + 0x676f02d9, 14);
257 MD5STEP (F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
258
259 MD5STEP (F3, a, b, c, d, in[5] + 0xfffa3942, 4);
260 MD5STEP (F3, d, a, b, c, in[8] + 0x8771f681, 11);
261 MD5STEP (F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
262 MD5STEP (F3, b, c, d, a, in[14] + 0xfde5380c, 23);
263 MD5STEP (F3, a, b, c, d, in[1] + 0xa4beea44, 4);
264 MD5STEP (F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
265 MD5STEP (F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
266 MD5STEP (F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
267 MD5STEP (F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
268 MD5STEP (F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
269 MD5STEP (F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
270 MD5STEP (F3, b, c, d, a, in[6] + 0x04881d05, 23);
271 MD5STEP (F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
272 MD5STEP (F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
273 MD5STEP (F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
274 MD5STEP (F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
275
276 MD5STEP (F4, a, b, c, d, in[0] + 0xf4292244, 6);
277 MD5STEP (F4, d, a, b, c, in[7] + 0x432aff97, 10);
278 MD5STEP (F4, c, d, a, b, in[14] + 0xab9423a7, 15);
279 MD5STEP (F4, b, c, d, a, in[5] + 0xfc93a039, 21);
280 MD5STEP (F4, a, b, c, d, in[12] + 0x655b59c3, 6);
281 MD5STEP (F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
282 MD5STEP (F4, c, d, a, b, in[10] + 0xffeff47d, 15);
283 MD5STEP (F4, b, c, d, a, in[1] + 0x85845dd1, 21);
284 MD5STEP (F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
285 MD5STEP (F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
286 MD5STEP (F4, c, d, a, b, in[6] + 0xa3014314, 15);
287 MD5STEP (F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
288 MD5STEP (F4, a, b, c, d, in[4] + 0xf7537e82, 6);
289 MD5STEP (F4, d, a, b, c, in[11] + 0xbd3af235, 10);
290 MD5STEP (F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
291 MD5STEP (F4, b, c, d, a, in[9] + 0xeb86d391, 21);
292
293 buf[0] += a;
294 buf[1] += b;
295 buf[2] += c;
296 buf[3] += d;
297 }
298
299
300 /**
301 * md5_get_digest: get the md5 hash of a buffer
302 * @buffer: byte buffer
303 * @buffer_size: buffer size (in bytes)
304 * @digest: 16 bytes buffer receiving the hash code.
305 *
306 * Get the md5 hash of a buffer. The result is put in
307 * the 16 bytes buffer @digest .
308 **/
309 void
md5_get_digest(const char * buffer,unsigned int buffer_size,unsigned char digest[16])310 md5_get_digest (const char *buffer, unsigned int buffer_size, unsigned char digest[16])
311 {
312 MD5Context ctx;
313
314 md5_init (&ctx);
315 md5_update (&ctx, (unsigned char *) buffer, buffer_size);
316 md5_final (&ctx, digest);
317 }
318
319
320 /**
321 * md5_get_digest_from_file: get the md5 hash of a file
322 * @filename: file name
323 * @digest: 16 bytes buffer receiving the hash code.
324 *
325 * Get the md5 hash of a file. The result is put in
326 * the 16 bytes buffer @digest .
327 **/
328 void
md5_get_digest_from_file(const char * filename,unsigned char digest[16])329 md5_get_digest_from_file (const char *filename, unsigned char digest[16])
330 {
331 MD5Context ctx;
332 unsigned char buf[1024];
333 size_t nread;
334 FILE *fp;
335
336 d(fprintf (stderr, "generating checksum\n"));
337
338 if (!(fp = fopen (filename, "rb")))
339 return;
340
341 md5_init (&ctx);
342
343 while ((nread = fread (buf, 1, 1024, fp)) > 0)
344 md5_update (&ctx, buf, nread);
345
346 if (ferror (fp)) {
347 fclose (fp);
348 return;
349 }
350
351 md5_final (&ctx, digest);
352
353 fclose (fp);
354 d(fprintf (stderr, "checksum done\n"));
355 }
356