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comparison: netwerk/srtp/src/crypto/cipher/cipher.c

netwerk/srtp/src/crypto/cipher/cipher.c

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1 /*
2 * cipher.c
3 *
4 * cipher meta-functions
5 *
6 * David A. McGrew
7 * Cisco Systems, Inc.
8 *
9 */
10
11 /*
12 *
13 * Copyright (c) 2001-2006, Cisco Systems, Inc.
14 * All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 *
20 * Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 *
23 * Redistributions in binary form must reproduce the above
24 * copyright notice, this list of conditions and the following
25 * disclaimer in the documentation and/or other materials provided
26 * with the distribution.
27 *
28 * Neither the name of the Cisco Systems, Inc. nor the names of its
29 * contributors may be used to endorse or promote products derived
30 * from this software without specific prior written permission.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
35 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
36 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
38 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
39 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
43 * OF THE POSSIBILITY OF SUCH DAMAGE.
44 *
45 */
46
47 #include "cipher.h"
48 #include "rand_source.h" /* used in invertibiltiy tests */
49 #include "alloc.h" /* for crypto_alloc(), crypto_free() */
50
51 debug_module_t mod_cipher = {
52 0, /* debugging is off by default */
53 "cipher" /* printable module name */
54 };
55
56 err_status_t
57 cipher_output(cipher_t *c, uint8_t *buffer, int num_octets_to_output) {
58
59 /* zeroize the buffer */
60 octet_string_set_to_zero(buffer, num_octets_to_output);
61
62 /* exor keystream into buffer */
63 return cipher_encrypt(c, buffer, (unsigned int *) &num_octets_to_output);
64 }
65
66 /* some bookkeeping functions */
67
68 int
69 cipher_get_key_length(const cipher_t *c) {
70 return c->key_len;
71 }
72
73 /*
74 * cipher_type_test(ct, test_data) tests a cipher of type ct against
75 * test cases provided in a list test_data of values of key, salt, iv,
76 * plaintext, and ciphertext that is known to be good
77 */
78
79 #define SELF_TEST_BUF_OCTETS 128
80 #define NUM_RAND_TESTS 128
81 #define MAX_KEY_LEN 64
82
83 err_status_t
84 cipher_type_test(const cipher_type_t *ct, const cipher_test_case_t *test_data) {
85 const cipher_test_case_t *test_case = test_data;
86 cipher_t *c;
87 err_status_t status;
88 uint8_t buffer[SELF_TEST_BUF_OCTETS];
89 uint8_t buffer2[SELF_TEST_BUF_OCTETS];
90 unsigned int len;
91 int i, j, case_num = 0;
92
93 debug_print(mod_cipher, "running self-test for cipher %s",
94 ct->description);
95
96 /*
97 * check to make sure that we have at least one test case, and
98 * return an error if we don't - we need to be paranoid here
99 */
100 if (test_case == NULL)
101 return err_status_cant_check;
102
103 /*
104 * loop over all test cases, perform known-answer tests of both the
105 * encryption and decryption functions
106 */
107 while (test_case != NULL) {
108
109 /* allocate cipher */
110 status = cipher_type_alloc(ct, &c, test_case->key_length_octets);
111 if (status)
112 return status;
113
114 /*
115 * test the encrypt function
116 */
117 debug_print(mod_cipher, "testing encryption", NULL);
118
119 /* initialize cipher */
120 status = cipher_init(c, test_case->key, direction_encrypt);
121 if (status) {
122 cipher_dealloc(c);
123 return status;
124 }
125
126 /* copy plaintext into test buffer */
127 if (test_case->ciphertext_length_octets > SELF_TEST_BUF_OCTETS) {
128 cipher_dealloc(c);
129 return err_status_bad_param;
130 }
131 for (i=0; i < test_case->plaintext_length_octets; i++)
132 buffer[i] = test_case->plaintext[i];
133
134 debug_print(mod_cipher, "plaintext: %s",
135 octet_string_hex_string(buffer,
136 test_case->plaintext_length_octets));
137
138 /* set the initialization vector */
139 status = cipher_set_iv(c, test_case->idx);
140 if (status) {
141 cipher_dealloc(c);
142 return status;
143 }
144
145 /* encrypt */
146 len = test_case->plaintext_length_octets;
147 status = cipher_encrypt(c, buffer, &len);
148 if (status) {
149 cipher_dealloc(c);
150 return status;
151 }
152
153 debug_print(mod_cipher, "ciphertext: %s",
154 octet_string_hex_string(buffer,
155 test_case->ciphertext_length_octets));
156
157 /* compare the resulting ciphertext with that in the test case */
158 if (len != (unsigned int)test_case->ciphertext_length_octets)
159 return err_status_algo_fail;
160 status = err_status_ok;
161 for (i=0; i < test_case->ciphertext_length_octets; i++)
162 if (buffer[i] != test_case->ciphertext[i]) {
163 status = err_status_algo_fail;
164 debug_print(mod_cipher, "test case %d failed", case_num);
165 debug_print(mod_cipher, "(failure at byte %d)", i);
166 break;
167 }
168 if (status) {
169
170 debug_print(mod_cipher, "c computed: %s",
171 octet_string_hex_string(buffer,
172 2*test_case->plaintext_length_octets));
173 debug_print(mod_cipher, "c expected: %s",
174 octet_string_hex_string(test_case->ciphertext,
175 2*test_case->plaintext_length_octets));
176
177 cipher_dealloc(c);
178 return err_status_algo_fail;
179 }
180
181 /*
182 * test the decrypt function
183 */
184 debug_print(mod_cipher, "testing decryption", NULL);
185
186 /* re-initialize cipher for decryption */
187 status = cipher_init(c, test_case->key, direction_decrypt);
188 if (status) {
189 cipher_dealloc(c);
190 return status;
191 }
192
193 /* copy ciphertext into test buffer */
194 if (test_case->ciphertext_length_octets > SELF_TEST_BUF_OCTETS) {
195 cipher_dealloc(c);
196 return err_status_bad_param;
197 }
198 for (i=0; i < test_case->ciphertext_length_octets; i++)
199 buffer[i] = test_case->ciphertext[i];
200
201 debug_print(mod_cipher, "ciphertext: %s",
202 octet_string_hex_string(buffer,
203 test_case->plaintext_length_octets));
204
205 /* set the initialization vector */
206 status = cipher_set_iv(c, test_case->idx);
207 if (status) {
208 cipher_dealloc(c);
209 return status;
210 }
211
212 /* decrypt */
213 len = test_case->ciphertext_length_octets;
214 status = cipher_decrypt(c, buffer, &len);
215 if (status) {
216 cipher_dealloc(c);
217 return status;
218 }
219
220 debug_print(mod_cipher, "plaintext: %s",
221 octet_string_hex_string(buffer,
222 test_case->plaintext_length_octets));
223
224 /* compare the resulting plaintext with that in the test case */
225 if (len != (unsigned int)test_case->plaintext_length_octets)
226 return err_status_algo_fail;
227 status = err_status_ok;
228 for (i=0; i < test_case->plaintext_length_octets; i++)
229 if (buffer[i] != test_case->plaintext[i]) {
230 status = err_status_algo_fail;
231 debug_print(mod_cipher, "test case %d failed", case_num);
232 debug_print(mod_cipher, "(failure at byte %d)", i);
233 }
234 if (status) {
235
236 debug_print(mod_cipher, "p computed: %s",
237 octet_string_hex_string(buffer,
238 2*test_case->plaintext_length_octets));
239 debug_print(mod_cipher, "p expected: %s",
240 octet_string_hex_string(test_case->plaintext,
241 2*test_case->plaintext_length_octets));
242
243 cipher_dealloc(c);
244 return err_status_algo_fail;
245 }
246
247 /* deallocate the cipher */
248 status = cipher_dealloc(c);
249 if (status)
250 return status;
251
252 /*
253 * the cipher passed the test case, so move on to the next test
254 * case in the list; if NULL, we'l proceed to the next test
255 */
256 test_case = test_case->next_test_case;
257 ++case_num;
258 }
259
260 /* now run some random invertibility tests */
261
262 /* allocate cipher, using paramaters from the first test case */
263 test_case = test_data;
264 status = cipher_type_alloc(ct, &c, test_case->key_length_octets);
265 if (status)
266 return status;
267
268 rand_source_init();
269
270 for (j=0; j < NUM_RAND_TESTS; j++) {
271 unsigned length;
272 int plaintext_len;
273 uint8_t key[MAX_KEY_LEN];
274 uint8_t iv[MAX_KEY_LEN];
275
276 /* choose a length at random (leaving room for IV and padding) */
277 length = rand() % (SELF_TEST_BUF_OCTETS - 64);
278 debug_print(mod_cipher, "random plaintext length %d\n", length);
279 status = rand_source_get_octet_string(buffer, length);
280 if (status) return status;
281
282 debug_print(mod_cipher, "plaintext: %s",
283 octet_string_hex_string(buffer, length));
284
285 /* copy plaintext into second buffer */
286 for (i=0; (unsigned int)i < length; i++)
287 buffer2[i] = buffer[i];
288
289 /* choose a key at random */
290 if (test_case->key_length_octets > MAX_KEY_LEN)
291 return err_status_cant_check;
292 status = rand_source_get_octet_string(key, test_case->key_length_octets);
293 if (status) return status;
294
295 /* chose a random initialization vector */
296 status = rand_source_get_octet_string(iv, MAX_KEY_LEN);
297 if (status) return status;
298
299 /* initialize cipher */
300 status = cipher_init(c, key, direction_encrypt);
301 if (status) {
302 cipher_dealloc(c);
303 return status;
304 }
305
306 /* set initialization vector */
307 status = cipher_set_iv(c, test_case->idx);
308 if (status) {
309 cipher_dealloc(c);
310 return status;
311 }
312
313 /* encrypt buffer with cipher */
314 plaintext_len = length;
315 status = cipher_encrypt(c, buffer, &length);
316 if (status) {
317 cipher_dealloc(c);
318 return status;
319 }
320 debug_print(mod_cipher, "ciphertext: %s",
321 octet_string_hex_string(buffer, length));
322
323 /*
324 * re-initialize cipher for decryption, re-set the iv, then
325 * decrypt the ciphertext
326 */
327 status = cipher_init(c, key, direction_decrypt);
328 if (status) {
329 cipher_dealloc(c);
330 return status;
331 }
332 status = cipher_set_iv(c, test_case->idx);
333 if (status) {
334 cipher_dealloc(c);
335 return status;
336 }
337 status = cipher_decrypt(c, buffer, &length);
338 if (status) {
339 cipher_dealloc(c);
340 return status;
341 }
342
343 debug_print(mod_cipher, "plaintext[2]: %s",
344 octet_string_hex_string(buffer, length));
345
346 /* compare the resulting plaintext with the original one */
347 if (length != (unsigned)plaintext_len)
348 return err_status_algo_fail;
349 status = err_status_ok;
350 for (i=0; i < plaintext_len; i++)
351 if (buffer[i] != buffer2[i]) {
352 status = err_status_algo_fail;
353 debug_print(mod_cipher, "random test case %d failed", case_num);
354 debug_print(mod_cipher, "(failure at byte %d)", i);
355 }
356 if (status) {
357 cipher_dealloc(c);
358 return err_status_algo_fail;
359 }
360
361 }
362
363 status = cipher_dealloc(c);
364 if (status)
365 return status;
366
367 return err_status_ok;
368 }
369
370
371 /*
372 * cipher_type_self_test(ct) performs cipher_type_test on ct's internal
373 * list of test data.
374 */
375
376 err_status_t
377 cipher_type_self_test(const cipher_type_t *ct) {
378 return cipher_type_test(ct, ct->test_data);
379 }
380
381 /*
382 * cipher_bits_per_second(c, l, t) computes (an estimate of) the
383 * number of bits that a cipher implementation can encrypt in a second
384 *
385 * c is a cipher (which MUST be allocated and initialized already), l
386 * is the length in octets of the test data to be encrypted, and t is
387 * the number of trials
388 *
389 * if an error is encountered, the value 0 is returned
390 */
391
392 uint64_t
393 cipher_bits_per_second(cipher_t *c, int octets_in_buffer, int num_trials) {
394 int i;
395 v128_t nonce;
396 clock_t timer;
397 unsigned char *enc_buf;
398 unsigned int len = octets_in_buffer;
399
400 enc_buf = (unsigned char*) crypto_alloc(octets_in_buffer);
401 if (enc_buf == NULL)
402 return 0; /* indicate bad parameters by returning null */
403
404 /* time repeated trials */
405 v128_set_to_zero(&nonce);
406 timer = clock();
407 for(i=0; i < num_trials; i++, nonce.v32[3] = i) {
408 cipher_set_iv(c, &nonce);
409 cipher_encrypt(c, enc_buf, &len);
410 }
411 timer = clock() - timer;
412
413 crypto_free(enc_buf);
414
415 if (timer == 0) {
416 /* Too fast! */
417 return 0;
418 }
419
420 return (uint64_t)CLOCKS_PER_SEC * num_trials * 8 * octets_in_buffer / timer;
421 }

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