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