5cf4643b84fc28670c634e083c172d1222ff34e3
[strongswan.git] / src / libstrongswan / crypto / hashers / md5_hasher.c
1 /**
2 * @file md5_hasher.c
3 *
4 * @brief Implementation of md5_hasher_t.
5 *
6 */
7
8 /*
9 * Copyright (C) 2005-2006 Martin Willi
10 * Copyright (C) 2005 Jan Hutter
11 * Hochschule fuer Technik Rapperswil
12 * Copyright (C) 1991-1992, RSA Data Security, Inc. Created 1991.
13 * All rights reserved.
14 *
15 * Derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm.
16 * Ported to fulfill hasher_t interface.
17 *
18 * This program is free software; you can redistribute it and/or modify it
19 * under the terms of the GNU General Public License as published by the
20 * Free Software Foundation; either version 2 of the License, or (at your
21 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
22 *
23 * This program is distributed in the hope that it will be useful, but
24 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
25 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
26 * for more details.
27 */
28
29 #include <string.h>
30
31 #include "md5_hasher.h"
32
33 #include <definitions.h>
34
35
36 /* Constants for MD5Transform routine. */
37 #define S11 7
38 #define S12 12
39 #define S13 17
40 #define S14 22
41 #define S21 5
42 #define S22 9
43 #define S23 14
44 #define S24 20
45 #define S31 4
46 #define S32 11
47 #define S33 16
48 #define S34 23
49 #define S41 6
50 #define S42 10
51 #define S43 15
52 #define S44 21
53
54 static u_int8_t PADDING[64] = {
55 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
56 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
57 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
58 };
59
60 /*
61 * ugly macro stuff
62 */
63 /* F, G, H and I are basic MD5 functions.
64 */
65 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
66 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
67 #define H(x, y, z) ((x) ^ (y) ^ (z))
68 #define I(x, y, z) ((y) ^ ((x) | (~z)))
69
70 /* ROTATE_LEFT rotates x left n bits.
71 */
72 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
73
74 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
75 Rotation is separate from addition to prevent recomputation.
76 */
77 #define FF(a, b, c, d, x, s, ac) { \
78 (a) += F ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
79 (a) = ROTATE_LEFT ((a), (s)); \
80 (a) += (b); \
81 }
82 #define GG(a, b, c, d, x, s, ac) { \
83 (a) += G ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
84 (a) = ROTATE_LEFT ((a), (s)); \
85 (a) += (b); \
86 }
87 #define HH(a, b, c, d, x, s, ac) { \
88 (a) += H ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
89 (a) = ROTATE_LEFT ((a), (s)); \
90 (a) += (b); \
91 }
92 #define II(a, b, c, d, x, s, ac) { \
93 (a) += I ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
94 (a) = ROTATE_LEFT ((a), (s)); \
95 (a) += (b); \
96 }
97
98
99
100 typedef struct private_md5_hasher_t private_md5_hasher_t;
101
102 /**
103 * Private data structure with hasing context.
104 */
105 struct private_md5_hasher_t {
106 /**
107 * Public interface for this hasher.
108 */
109 md5_hasher_t public;
110
111 /*
112 * State of the hasher.
113 */
114 u_int32_t state[5];
115 u_int32_t count[2];
116 u_int8_t buffer[64];
117 };
118
119
120 #if BYTE_ORDER != LITTLE_ENDIAN
121
122 /* Encodes input (u_int32_t) into output (u_int8_t). Assumes len is
123 * a multiple of 4.
124 */
125 static void Encode (u_int8_t *output, u_int32_t *input, size_t *len)
126 {
127 size_t i, j;
128
129 for (i = 0, j = 0; j < len; i++, j += 4)
130 {
131 output[j] = (u_int8_t)(input[i] & 0xff);
132 output[j+1] = (u_int8_t)((input[i] >> 8) & 0xff);
133 output[j+2] = (u_int8_t)((input[i] >> 16) & 0xff);
134 output[j+3] = (u_int8_t)((input[i] >> 24) & 0xff);
135 }
136 }
137
138 /* Decodes input (u_int8_t) into output (u_int32_t). Assumes len is
139 * a multiple of 4.
140 */
141 static void Decode(u_int32_t *output, u_int8_t *input, size_t len)
142 {
143 size_t i, j;
144
145 for (i = 0, j = 0; j < len; i++, j += 4)
146 {
147 output[i] = ((u_int32_t)input[j]) | (((u_int32_t)input[j+1]) << 8) |
148 (((u_int32_t)input[j+2]) << 16) | (((u_int32_t)input[j+3]) << 24);
149 }
150 }
151
152 #elif BYTE_ORDER == LITTLE_ENDIAN
153 #define Encode memcpy
154 #define Decode memcpy
155 #endif
156
157 /* MD5 basic transformation. Transforms state based on block.
158 */
159 static void MD5Transform(u_int32_t state[4], u_int8_t block[64])
160 {
161 u_int32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
162
163 Decode(x, block, 64);
164
165 /* Round 1 */
166 FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
167 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
168 FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
169 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
170 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
171 FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
172 FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
173 FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
174 FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
175 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
176 FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
177 FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
178 FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
179 FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
180 FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
181 FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
182
183 /* Round 2 */
184 GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
185 GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
186 GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
187 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
188 GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
189 GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
190 GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
191 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
192 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
193 GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
194 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
195 GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
196 GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
197 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
198 GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
199 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
200
201 /* Round 3 */
202 HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
203 HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
204 HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
205 HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
206 HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
207 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
208 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
209 HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
210 HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
211 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
212 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
213 HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
214 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
215 HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
216 HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
217 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
218
219 /* Round 4 */
220 II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
221 II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
222 II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
223 II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
224 II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
225 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
226 II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
227 II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
228 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
229 II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
230 II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
231 II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
232 II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
233 II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
234 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
235 II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
236
237 state[0] += a;
238 state[1] += b;
239 state[2] += c;
240 state[3] += d;
241 }
242
243 /* MD5 block update operation. Continues an MD5 message-digest
244 * operation, processing another message block, and updating the
245 * context.
246 */
247 static void MD5Update(private_md5_hasher_t *this, u_int8_t *input, size_t inputLen)
248 {
249 u_int32_t i;
250 size_t index, partLen;
251
252 /* Compute number of bytes mod 64 */
253 index = (u_int8_t)((this->count[0] >> 3) & 0x3F);
254
255 /* Update number of bits */
256 if ((this->count[0] += (inputLen << 3)) < (inputLen << 3))
257 {
258 this->count[1]++;
259 }
260 this->count[1] += (inputLen >> 29);
261
262 partLen = 64 - index;
263
264 /* Transform as many times as possible. */
265 if (inputLen >= partLen)
266 {
267 memcpy(&this->buffer[index], input, partLen);
268 MD5Transform (this->state, this->buffer);
269
270 for (i = partLen; i + 63 < inputLen; i += 64)
271 {
272 MD5Transform (this->state, &input[i]);
273 }
274 index = 0;
275 }
276 else
277 {
278 i = 0;
279 }
280
281 /* Buffer remaining input */
282 memcpy(&this->buffer[index], &input[i], inputLen-i);
283 }
284
285 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
286 * the message digest and zeroizing the context.
287 */
288 static void MD5Final (private_md5_hasher_t *this, u_int8_t digest[16])
289 {
290 u_int8_t bits[8];
291 size_t index, padLen;
292
293 /* Save number of bits */
294 Encode (bits, this->count, 8);
295
296 /* Pad out to 56 mod 64. */
297 index = (size_t)((this->count[0] >> 3) & 0x3f);
298 padLen = (index < 56) ? (56 - index) : (120 - index);
299 MD5Update (this, PADDING, padLen);
300
301 /* Append length (before padding) */
302 MD5Update (this, bits, 8);
303
304 if (digest != NULL) /* Bill Simpson's padding */
305 {
306 /* store state in digest */
307 Encode (digest, this->state, 16);
308 }
309 }
310
311
312
313 /**
314 * Implementation of hasher_t.get_hash.
315 */
316 static void get_hash(private_md5_hasher_t *this, chunk_t chunk, u_int8_t *buffer)
317 {
318 MD5Update(this, chunk.ptr, chunk.len);
319 if (buffer != NULL)
320 {
321 MD5Final(this, buffer);
322 this->public.hasher_interface.reset(&(this->public.hasher_interface));
323 }
324 }
325
326
327 /**
328 * Implementation of hasher_t.allocate_hash.
329 */
330 static void allocate_hash(private_md5_hasher_t *this, chunk_t chunk, chunk_t *hash)
331 {
332 chunk_t allocated_hash;
333
334 MD5Update(this, chunk.ptr, chunk.len);
335 if (hash != NULL)
336 {
337 allocated_hash.ptr = malloc(HASH_SIZE_MD5);
338 allocated_hash.len = HASH_SIZE_MD5;
339
340 MD5Final(this, allocated_hash.ptr);
341 this->public.hasher_interface.reset(&(this->public.hasher_interface));
342
343 *hash = allocated_hash;
344 }
345 }
346
347 /**
348 * Implementation of hasher_t.get_hash_size.
349 */
350 static size_t get_hash_size(private_md5_hasher_t *this)
351 {
352 return HASH_SIZE_MD5;
353 }
354
355 /**
356 * Implementation of hasher_t.reset.
357 */
358 static void reset(private_md5_hasher_t *this)
359 {
360 this->state[0] = 0x67452301;
361 this->state[1] = 0xefcdab89;
362 this->state[2] = 0x98badcfe;
363 this->state[3] = 0x10325476;
364 this->count[0] = 0;
365 this->count[1] = 0;
366 }
367
368 /**
369 * Implementation of hasher_t.destroy.
370 */
371 static void destroy(private_md5_hasher_t *this)
372 {
373 free(this);
374 }
375
376 /*
377 * Described in header.
378 */
379 md5_hasher_t *md5_hasher_create(void)
380 {
381 private_md5_hasher_t *this = malloc_thing(private_md5_hasher_t);
382
383 this->public.hasher_interface.get_hash = (void (*) (hasher_t*, chunk_t, u_int8_t*))get_hash;
384 this->public.hasher_interface.allocate_hash = (void (*) (hasher_t*, chunk_t, chunk_t*))allocate_hash;
385 this->public.hasher_interface.get_hash_size = (size_t (*) (hasher_t*))get_hash_size;
386 this->public.hasher_interface.reset = (void (*) (hasher_t*))reset;
387 this->public.hasher_interface.destroy = (void (*) (hasher_t*))destroy;
388
389 /* initialize */
390 reset(this);
391
392 return &(this->public);
393 }