Annotation of embedaddon/strongswan/src/libstrongswan/plugins/md4/md4_hasher.c, revision 1.1.1.1
1.1 misho 1: /*
2: * Copyright (C) 2005-2006 Martin Willi
3: * Copyright (C) 2005 Jan Hutter
4: * HSR Hochschule fuer Technik Rapperswil
5: * Copyright (C) 1990-1992, RSA Data Security, Inc. Created 1990.
6: * All rights reserved.
7: *
8: * Derived from the RSA Data Security, Inc. MD4 Message-Digest Algorithm.
9: * Ported to fulfill hasher_t interface.
10: *
11: * This program is free software; you can redistribute it and/or modify it
12: * under the terms of the GNU General Public License as published by the
13: * Free Software Foundation; either version 2 of the License, or (at your
14: * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
15: *
16: * This program is distributed in the hope that it will be useful, but
17: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
18: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19: * for more details.
20: */
21:
22: #include <string.h>
23:
24: #include "md4_hasher.h"
25:
26: /*
27: * Constants for MD4Transform routine.
28: */
29: #define S11 3
30: #define S12 7
31: #define S13 11
32: #define S14 19
33: #define S21 3
34: #define S22 5
35: #define S23 9
36: #define S24 13
37: #define S31 3
38: #define S32 9
39: #define S33 11
40: #define S34 15
41:
42: static uint8_t PADDING[64] = {
43: 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
44: 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
45: 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
46: };
47:
48: /*
49: * F, G, H and I are basic MD4 functions.
50: */
51: #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
52: #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
53: #define H(x, y, z) ((x) ^ (y) ^ (z))
54:
55: /*
56: * ROTATE_LEFT rotates x left n bits.
57: */
58: #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
59:
60: /* FF, GG and HH are transformations for rounds 1, 2 and 3
61: * Rotation is separate from addition to prevent recomputation
62: */
63: #define FF(a, b, c, d, x, s) { \
64: (a) += F ((b), (c), (d)) + (x); \
65: (a) = ROTATE_LEFT ((a), (s)); \
66: }
67: #define GG(a, b, c, d, x, s) { \
68: (a) += G ((b), (c), (d)) + (x) + (uint32_t)0x5a827999; \
69: (a) = ROTATE_LEFT ((a), (s)); \
70: }
71: #define HH(a, b, c, d, x, s) { \
72: (a) += H ((b), (c), (d)) + (x) + (uint32_t)0x6ed9eba1; \
73: (a) = ROTATE_LEFT ((a), (s)); \
74: }
75:
76: typedef struct private_md4_hasher_t private_md4_hasher_t;
77:
78: /**
79: * Private data structure with hashing context.
80: */
81: struct private_md4_hasher_t {
82: /**
83: * Public interface for this hasher.
84: */
85: md4_hasher_t public;
86:
87: /*
88: * State of the hasher.
89: */
90: uint32_t state[4];
91: uint32_t count[2];
92: uint8_t buffer[64];
93: };
94:
95: #if BYTE_ORDER != LITTLE_ENDIAN
96:
97: /* Encodes input (uint32_t) into output (uint8_t). Assumes len is
98: * a multiple of 4.
99: */
100: static void Encode (uint8_t *output, uint32_t *input, size_t len)
101: {
102: size_t i, j;
103:
104: for (i = 0, j = 0; j < len; i++, j += 4)
105: {
106: output[j] = (uint8_t)(input[i] & 0xff);
107: output[j+1] = (uint8_t)((input[i] >> 8) & 0xff);
108: output[j+2] = (uint8_t)((input[i] >> 16) & 0xff);
109: output[j+3] = (uint8_t)((input[i] >> 24) & 0xff);
110: }
111: }
112:
113: /* Decodes input (uint8_t) into output (uint32_t). Assumes len is
114: * a multiple of 4.
115: */
116: static void Decode(uint32_t *output, uint8_t *input, size_t len)
117: {
118: size_t i, j;
119:
120: for (i = 0, j = 0; j < len; i++, j += 4)
121: {
122: output[i] = ((uint32_t)input[j]) | (((uint32_t)input[j+1]) << 8) |
123: (((uint32_t)input[j+2]) << 16) | (((uint32_t)input[j+3]) << 24);
124: }
125: }
126:
127: #elif BYTE_ORDER == LITTLE_ENDIAN
128: #define Encode memcpy
129: #define Decode memcpy
130: #endif
131:
132: /*
133: * MD4 basic transformation. Transforms state based on block.
134: */
135: static void MD4Transform(uint32_t state[4], uint8_t block[64])
136: {
137: uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
138:
139: Decode(x, block, 64);
140:
141: /* Round 1 */
142: FF (a, b, c, d, x[ 0], S11); /* 1 */
143: FF (d, a, b, c, x[ 1], S12); /* 2 */
144: FF (c, d, a, b, x[ 2], S13); /* 3 */
145: FF (b, c, d, a, x[ 3], S14); /* 4 */
146: FF (a, b, c, d, x[ 4], S11); /* 5 */
147: FF (d, a, b, c, x[ 5], S12); /* 6 */
148: FF (c, d, a, b, x[ 6], S13); /* 7 */
149: FF (b, c, d, a, x[ 7], S14); /* 8 */
150: FF (a, b, c, d, x[ 8], S11); /* 9 */
151: FF (d, a, b, c, x[ 9], S12); /* 10 */
152: FF (c, d, a, b, x[10], S13); /* 11 */
153: FF (b, c, d, a, x[11], S14); /* 12 */
154: FF (a, b, c, d, x[12], S11); /* 13 */
155: FF (d, a, b, c, x[13], S12); /* 14 */
156: FF (c, d, a, b, x[14], S13); /* 15 */
157: FF (b, c, d, a, x[15], S14); /* 16 */
158:
159: /* Round 2 */
160: GG (a, b, c, d, x[ 0], S21); /* 17 */
161: GG (d, a, b, c, x[ 4], S22); /* 18 */
162: GG (c, d, a, b, x[ 8], S23); /* 19 */
163: GG (b, c, d, a, x[12], S24); /* 20 */
164: GG (a, b, c, d, x[ 1], S21); /* 21 */
165: GG (d, a, b, c, x[ 5], S22); /* 22 */
166: GG (c, d, a, b, x[ 9], S23); /* 23 */
167: GG (b, c, d, a, x[13], S24); /* 24 */
168: GG (a, b, c, d, x[ 2], S21); /* 25 */
169: GG (d, a, b, c, x[ 6], S22); /* 26 */
170: GG (c, d, a, b, x[10], S23); /* 27 */
171: GG (b, c, d, a, x[14], S24); /* 28 */
172: GG (a, b, c, d, x[ 3], S21); /* 29 */
173: GG (d, a, b, c, x[ 7], S22); /* 30 */
174: GG (c, d, a, b, x[11], S23); /* 31 */
175: GG (b, c, d, a, x[15], S24); /* 32 */
176:
177: /* Round 3 */
178: HH (a, b, c, d, x[ 0], S31); /* 33 */
179: HH (d, a, b, c, x[ 8], S32); /* 34 */
180: HH (c, d, a, b, x[ 4], S33); /* 35 */
181: HH (b, c, d, a, x[12], S34); /* 36 */
182: HH (a, b, c, d, x[ 2], S31); /* 37 */
183: HH (d, a, b, c, x[10], S32); /* 38 */
184: HH (c, d, a, b, x[ 6], S33); /* 39 */
185: HH (b, c, d, a, x[14], S34); /* 40 */
186: HH (a, b, c, d, x[ 1], S31); /* 41 */
187: HH (d, a, b, c, x[ 9], S32); /* 42 */
188: HH (c, d, a, b, x[ 5], S33); /* 43 */
189: HH (b, c, d, a, x[13], S34); /* 44 */
190: HH (a, b, c, d, x[ 3], S31); /* 45 */
191: HH (d, a, b, c, x[11], S32); /* 46 */
192: HH (c, d, a, b, x[ 7], S33); /* 47 */
193: HH (b, c, d, a, x[15], S34); /* 48 */
194:
195: state[0] += a;
196: state[1] += b;
197: state[2] += c;
198: state[3] += d;
199: }
200:
201: /* MD4 block update operation. Continues an MD4 message-digest
202: * operation, processing another message block, and updating the
203: * context.
204: */
205: static void MD4Update(private_md4_hasher_t *this, uint8_t *input, size_t inputLen)
206: {
207: uint32_t i;
208: size_t index, partLen;
209:
210: /* Compute number of bytes mod 64 */
211: index = (uint8_t)((this->count[0] >> 3) & 0x3F);
212:
213: /* Update number of bits */
214: if ((this->count[0] += (inputLen << 3)) < (inputLen << 3))
215: {
216: this->count[1]++;
217: }
218: this->count[1] += (inputLen >> 29);
219:
220: partLen = 64 - index;
221:
222: /* Transform as many times as possible. */
223: if (inputLen >= partLen)
224: {
225: memcpy(&this->buffer[index], input, partLen);
226: MD4Transform (this->state, this->buffer);
227:
228: for (i = partLen; i + 63 < inputLen; i += 64)
229: {
230: MD4Transform (this->state, &input[i]);
231: }
232: index = 0;
233: }
234: else
235: {
236: i = 0;
237: }
238:
239: /* Buffer remaining input */
240: memcpy(&this->buffer[index], &input[i], inputLen-i);
241: }
242:
243: /* MD4 finalization. Ends an MD4 message-digest operation, writing the
244: * the message digest and zeroizing the context.
245: */
246: static void MD4Final (private_md4_hasher_t *this, uint8_t digest[16])
247: {
248: uint8_t bits[8];
249: size_t index, padLen;
250:
251: /* Save number of bits */
252: Encode (bits, this->count, 8);
253:
254: /* Pad out to 56 mod 64. */
255: index = (size_t)((this->count[0] >> 3) & 0x3f);
256: padLen = (index < 56) ? (56 - index) : (120 - index);
257: MD4Update (this, PADDING, padLen);
258:
259: /* Append length (before padding) */
260: MD4Update (this, bits, 8);
261:
262: if (digest != NULL) /* Bill Simpson's padding */
263: {
264: /* store state in digest */
265: Encode (digest, this->state, 16);
266: }
267: }
268:
269: METHOD(hasher_t, reset, bool,
270: private_md4_hasher_t *this)
271: {
272: this->state[0] = 0x67452301;
273: this->state[1] = 0xefcdab89;
274: this->state[2] = 0x98badcfe;
275: this->state[3] = 0x10325476;
276: this->count[0] = 0;
277: this->count[1] = 0;
278:
279: return TRUE;
280: }
281:
282: METHOD(hasher_t, get_hash, bool,
283: private_md4_hasher_t *this, chunk_t chunk, uint8_t *buffer)
284: {
285: MD4Update(this, chunk.ptr, chunk.len);
286: if (buffer != NULL)
287: {
288: MD4Final(this, buffer);
289: reset(this);
290: }
291: return TRUE;
292: }
293:
294: METHOD(hasher_t, allocate_hash, bool,
295: private_md4_hasher_t *this, chunk_t chunk, chunk_t *hash)
296: {
297: chunk_t allocated_hash;
298:
299: MD4Update(this, chunk.ptr, chunk.len);
300: if (hash != NULL)
301: {
302: allocated_hash.ptr = malloc(HASH_SIZE_MD4);
303: allocated_hash.len = HASH_SIZE_MD4;
304:
305: MD4Final(this, allocated_hash.ptr);
306: reset(this);
307:
308: *hash = allocated_hash;
309: }
310: return TRUE;
311: }
312:
313: METHOD(hasher_t, get_hash_size, size_t,
314: private_md4_hasher_t *this)
315: {
316: return HASH_SIZE_MD4;
317: }
318:
319: METHOD(hasher_t, destroy, void,
320: private_md4_hasher_t *this)
321: {
322: free(this);
323: }
324:
325: /*
326: * Described in header.
327: */
328: md4_hasher_t *md4_hasher_create(hash_algorithm_t algo)
329: {
330: private_md4_hasher_t *this;
331:
332: if (algo != HASH_MD4)
333: {
334: return NULL;
335: }
336:
337: INIT(this,
338: .public = {
339: .hasher_interface = {
340: .get_hash = _get_hash,
341: .allocate_hash = _allocate_hash,
342: .get_hash_size = _get_hash_size,
343: .reset = _reset,
344: .destroy = _destroy,
345: },
346: },
347: );
348:
349: /* initialize */
350: reset(this);
351:
352: return &(this->public);
353: }
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