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[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 #define BLOCK_SIZE_MD5 16
36
37
38 /* Constants for MD5Transform routine. */
39 #define S11 7
40 #define S12 12
41 #define S13 17
42 #define S14 22
43 #define S21 5
44 #define S22 9
45 #define S23 14
46 #define S24 20
47 #define S31 4
48 #define S32 11
49 #define S33 16
50 #define S34 23
51 #define S41 6
52 #define S42 10
53 #define S43 15
54 #define S44 21
55
56 static u_int8_t PADDING[64] = {
57 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
58 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
59 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
60 };
61
62 /*
63 * ugly macro stuff
64 */
65 /* F, G, H and I are basic MD5 functions.
66 */
67 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
68 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
69 #define H(x, y, z) ((x) ^ (y) ^ (z))
70 #define I(x, y, z) ((y) ^ ((x) | (~z)))
71
72 /* ROTATE_LEFT rotates x left n bits.
73 */
74 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
75
76 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
77 Rotation is separate from addition to prevent recomputation.
78 */
79 #define FF(a, b, c, d, x, s, ac) { \
80 (a) += F ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
81 (a) = ROTATE_LEFT ((a), (s)); \
82 (a) += (b); \
83 }
84 #define GG(a, b, c, d, x, s, ac) { \
85 (a) += G ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
86 (a) = ROTATE_LEFT ((a), (s)); \
87 (a) += (b); \
88 }
89 #define HH(a, b, c, d, x, s, ac) { \
90 (a) += H ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
91 (a) = ROTATE_LEFT ((a), (s)); \
92 (a) += (b); \
93 }
94 #define II(a, b, c, d, x, s, ac) { \
95 (a) += I ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
96 (a) = ROTATE_LEFT ((a), (s)); \
97 (a) += (b); \
98 }
99
100
101
102 typedef struct private_md5_hasher_t private_md5_hasher_t;
103
104 /**
105 * Private data structure with hasing context.
106 */
107 struct private_md5_hasher_t {
108 /**
109 * Public interface for this hasher.
110 */
111 md5_hasher_t public;
112
113 /*
114 * State of the hasher.
115 */
116 u_int32_t state[5];
117 u_int32_t count[2];
118 u_int8_t buffer[64];
119 };
120
121
122 #if BYTE_ORDER != LITTLE_ENDIAN
123
124 /* Encodes input (u_int32_t) into output (u_int8_t). Assumes len is
125 * a multiple of 4.
126 */
127 static void Encode (u_int8_t *output, u_int32_t *input, size_t *len)
128 {
129 size_t i, j;
130
131 for (i = 0, j = 0; j < len; i++, j += 4)
132 {
133 output[j] = (u_int8_t)(input[i] & 0xff);
134 output[j+1] = (u_int8_t)((input[i] >> 8) & 0xff);
135 output[j+2] = (u_int8_t)((input[i] >> 16) & 0xff);
136 output[j+3] = (u_int8_t)((input[i] >> 24) & 0xff);
137 }
138 }
139
140 /* Decodes input (u_int8_t) into output (u_int32_t). Assumes len is
141 * a multiple of 4.
142 */
143 static void Decode(u_int32_t *output, u_int8_t *input, size_t len)
144 {
145 size_t i, j;
146
147 for (i = 0, j = 0; j < len; i++, j += 4)
148 {
149 output[i] = ((u_int32_t)input[j]) | (((u_int32_t)input[j+1]) << 8) |
150 (((u_int32_t)input[j+2]) << 16) | (((u_int32_t)input[j+3]) << 24);
151 }
152 }
153
154 #elif BYTE_ORDER == LITTLE_ENDIAN
155 #define Encode memcpy
156 #define Decode memcpy
157 #endif
158
159 /* MD5 basic transformation. Transforms state based on block.
160 */
161 static void MD5Transform(u_int32_t state[4], u_int8_t block[64])
162 {
163 u_int32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
164
165 Decode(x, block, 64);
166
167 /* Round 1 */
168 FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
169 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
170 FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
171 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
172 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
173 FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
174 FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
175 FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
176 FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
177 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
178 FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
179 FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
180 FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
181 FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
182 FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
183 FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
184
185 /* Round 2 */
186 GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
187 GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
188 GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
189 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
190 GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
191 GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
192 GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
193 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
194 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
195 GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
196 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
197 GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
198 GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
199 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
200 GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
201 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
202
203 /* Round 3 */
204 HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
205 HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
206 HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
207 HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
208 HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
209 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
210 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
211 HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
212 HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
213 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
214 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
215 HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
216 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
217 HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
218 HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
219 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
220
221 /* Round 4 */
222 II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
223 II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
224 II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
225 II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
226 II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
227 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
228 II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
229 II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
230 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
231 II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
232 II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
233 II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
234 II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
235 II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
236 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
237 II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
238
239 state[0] += a;
240 state[1] += b;
241 state[2] += c;
242 state[3] += d;
243 }
244
245 /* MD5 block update operation. Continues an MD5 message-digest
246 * operation, processing another message block, and updating the
247 * context.
248 */
249 static void MD5Update(private_md5_hasher_t *this, u_int8_t *input, size_t inputLen)
250 {
251 u_int32_t i;
252 size_t index, partLen;
253
254 /* Compute number of bytes mod 64 */
255 index = (u_int8_t)((this->count[0] >> 3) & 0x3F);
256
257 /* Update number of bits */
258 if ((this->count[0] += (inputLen << 3)) < (inputLen << 3))
259 {
260 this->count[1]++;
261 }
262 this->count[1] += (inputLen >> 29);
263
264 partLen = 64 - index;
265
266 /* Transform as many times as possible. */
267 if (inputLen >= partLen)
268 {
269 memcpy(&this->buffer[index], input, partLen);
270 MD5Transform (this->state, this->buffer);
271
272 for (i = partLen; i + 63 < inputLen; i += 64)
273 {
274 MD5Transform (this->state, &input[i]);
275 }
276 index = 0;
277 }
278 else
279 {
280 i = 0;
281 }
282
283 /* Buffer remaining input */
284 memcpy(&this->buffer[index], &input[i], inputLen-i);
285 }
286
287 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
288 * the message digest and zeroizing the context.
289 */
290 static void MD5Final (private_md5_hasher_t *this, u_int8_t digest[16])
291 {
292 u_int8_t bits[8];
293 size_t index, padLen;
294
295 /* Save number of bits */
296 Encode (bits, this->count, 8);
297
298 /* Pad out to 56 mod 64. */
299 index = (size_t)((this->count[0] >> 3) & 0x3f);
300 padLen = (index < 56) ? (56 - index) : (120 - index);
301 MD5Update (this, PADDING, padLen);
302
303 /* Append length (before padding) */
304 MD5Update (this, bits, 8);
305
306 if (digest != NULL) /* Bill Simpson's padding */
307 {
308 /* store state in digest */
309 Encode (digest, this->state, 16);
310 }
311 }
312
313
314
315 /**
316 * Implementation of hasher_t.get_hash.
317 */
318 static void get_hash(private_md5_hasher_t *this, chunk_t chunk, u_int8_t *buffer)
319 {
320 MD5Update(this, chunk.ptr, chunk.len);
321 if (buffer != NULL)
322 {
323 MD5Final(this, buffer);
324 this->public.hasher_interface.reset(&(this->public.hasher_interface));
325 }
326 }
327
328
329 /**
330 * Implementation of hasher_t.allocate_hash.
331 */
332 static void allocate_hash(private_md5_hasher_t *this, chunk_t chunk, chunk_t *hash)
333 {
334 chunk_t allocated_hash;
335
336 MD5Update(this, chunk.ptr, chunk.len);
337 if (hash != NULL)
338 {
339 allocated_hash.ptr = malloc(BLOCK_SIZE_MD5);
340 allocated_hash.len = BLOCK_SIZE_MD5;
341
342 MD5Final(this, allocated_hash.ptr);
343 this->public.hasher_interface.reset(&(this->public.hasher_interface));
344
345 *hash = allocated_hash;
346 }
347 }
348
349 /**
350 * Implementation of hasher_t.get_hash_size.
351 */
352 static size_t get_hash_size(private_md5_hasher_t *this)
353 {
354 return BLOCK_SIZE_MD5;
355 }
356
357 /**
358 * Implementation of hasher_t.reset.
359 */
360 static void reset(private_md5_hasher_t *this)
361 {
362 this->state[0] = 0x67452301;
363 this->state[1] = 0xefcdab89;
364 this->state[2] = 0x98badcfe;
365 this->state[3] = 0x10325476;
366 this->count[0] = 0;
367 this->count[1] = 0;
368 }
369
370 /**
371 * Implementation of hasher_t.destroy.
372 */
373 static void destroy(private_md5_hasher_t *this)
374 {
375 free(this);
376 }
377
378 /*
379 * Described in header.
380 */
381 md5_hasher_t *md5_hasher_create(void)
382 {
383 private_md5_hasher_t *this = malloc_thing(private_md5_hasher_t);
384
385 this->public.hasher_interface.get_hash = (void (*) (hasher_t*, chunk_t, u_int8_t*))get_hash;
386 this->public.hasher_interface.allocate_hash = (void (*) (hasher_t*, chunk_t, chunk_t*))allocate_hash;
387 this->public.hasher_interface.get_hash_size = (size_t (*) (hasher_t*))get_hash_size;
388 this->public.hasher_interface.reset = (void (*) (hasher_t*))reset;
389 this->public.hasher_interface.destroy = (void (*) (hasher_t*))destroy;
390
391 /* initialize */
392 reset(this);
393
394 return &(this->public);
395 }