1 /* ====================================================================
2 * Copyright (c) 2007 The OpenSSL Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in
13 * the documentation and/or other materials provided with the
14 * distribution.
15 *
16 * 3. All advertising materials mentioning features or use of this
17 * software must display the following acknowledgment:
18 * "This product includes software developed by the OpenSSL Project
19 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
20 *
21 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22 * endorse or promote products derived from this software without
23 * prior written permission. For written permission, please contact
24 * openssl-core@openssl.org.
25 *
26 * 5. Products derived from this software may not be called "OpenSSL"
27 * nor may "OpenSSL" appear in their names without prior written
28 * permission of the OpenSSL Project.
29 *
30 * 6. Redistributions of any form whatsoever must retain the following
31 * acknowledgment:
32 * "This product includes software developed by the OpenSSL Project
33 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46 * OF THE POSSIBILITY OF SUCH DAMAGE.
47 *
48 */
49
50 /*
51 * This is a FIPS approved AES PRNG based on ANSI X9.31 A.2.4.
52 */
53
54 #include "e_os.h"
55
56 /*
57 * If we don't define _XOPEN_SOURCE_EXTENDED, struct timeval won't be defined
58 * and gettimeofday() won't be declared with strict compilers like DEC C in
59 * ANSI C mode.
60 */
61 #ifndef _XOPEN_SOURCE_EXTENDED
62 # define _XOPEN_SOURCE_EXTENDED 1
63 #endif
64
65 #include <openssl/rand.h>
66 #include <openssl/aes.h>
67 #include <openssl/err.h>
68 #include <openssl/fips_rand.h>
69 #ifndef OPENSSL_SYS_WIN32
70 # include <sys/time.h>
71 #endif
72 #include <assert.h>
73 #ifndef OPENSSL_SYS_WIN32
74 # ifdef OPENSSL_UNISTD
75 # include OPENSSL_UNISTD
76 # else
77 # include <unistd.h>
78 # endif
79 #endif
80 #include <string.h>
81 #include <openssl/fips.h>
82 #include "fips_locl.h"
83
84 #ifdef OPENSSL_FIPS
85
86 void *OPENSSL_stderr(void);
87
88 # define AES_BLOCK_LENGTH 16
89
90 /* AES FIPS PRNG implementation */
91
92 typedef struct {
93 int seeded;
94 int keyed;
95 int test_mode;
96 int second;
97 int error;
98 unsigned long counter;
99 AES_KEY ks;
100 int vpos;
101 /* Temporary storage for key if it equals seed length */
102 unsigned char tmp_key[AES_BLOCK_LENGTH];
103 unsigned char V[AES_BLOCK_LENGTH];
104 unsigned char DT[AES_BLOCK_LENGTH];
105 unsigned char last[AES_BLOCK_LENGTH];
106 } FIPS_PRNG_CTX;
107
108 static FIPS_PRNG_CTX sctx;
109
110 static int fips_prng_fail = 0;
111
FIPS_rng_stick(void)112 void FIPS_rng_stick(void)
113 {
114 fips_prng_fail = 1;
115 }
116
fips_rand_prng_reset(FIPS_PRNG_CTX * ctx)117 static void fips_rand_prng_reset(FIPS_PRNG_CTX * ctx)
118 {
119 ctx->seeded = 0;
120 ctx->keyed = 0;
121 ctx->test_mode = 0;
122 ctx->counter = 0;
123 ctx->second = 0;
124 ctx->error = 0;
125 ctx->vpos = 0;
126 OPENSSL_cleanse(ctx->V, AES_BLOCK_LENGTH);
127 OPENSSL_cleanse(&ctx->ks, sizeof(AES_KEY));
128 }
129
fips_set_prng_key(FIPS_PRNG_CTX * ctx,const unsigned char * key,FIPS_RAND_SIZE_T keylen)130 static int fips_set_prng_key(FIPS_PRNG_CTX * ctx,
131 const unsigned char *key,
132 FIPS_RAND_SIZE_T keylen)
133 {
134 FIPS_selftest_check();
135 if (keylen != 16 && keylen != 24 && keylen != 32) {
136 /* error: invalid key size */
137 return 0;
138 }
139 AES_set_encrypt_key(key, keylen << 3, &ctx->ks);
140 if (keylen == 16) {
141 memcpy(ctx->tmp_key, key, 16);
142 ctx->keyed = 2;
143 } else
144 ctx->keyed = 1;
145 ctx->seeded = 0;
146 ctx->second = 0;
147 return 1;
148 }
149
fips_set_prng_seed(FIPS_PRNG_CTX * ctx,const unsigned char * seed,FIPS_RAND_SIZE_T seedlen)150 static int fips_set_prng_seed(FIPS_PRNG_CTX * ctx,
151 const unsigned char *seed,
152 FIPS_RAND_SIZE_T seedlen)
153 {
154 int i;
155 if (!ctx->keyed)
156 return 0;
157 /* In test mode seed is just supplied data */
158 if (ctx->test_mode) {
159 if (seedlen != AES_BLOCK_LENGTH)
160 return 0;
161 memcpy(ctx->V, seed, AES_BLOCK_LENGTH);
162 ctx->seeded = 1;
163 return 1;
164 }
165 /* Outside test mode XOR supplied data with existing seed */
166 for (i = 0; i < seedlen; i++) {
167 ctx->V[ctx->vpos++] ^= seed[i];
168 if (ctx->vpos == AES_BLOCK_LENGTH) {
169 ctx->vpos = 0;
170 /*
171 * Special case if first seed and key length equals block size
172 * check key and seed do not match.
173 */
174 if (ctx->keyed == 2) {
175 if (!memcmp(ctx->tmp_key, ctx->V, 16)) {
176 RANDerr(RAND_F_FIPS_SET_PRNG_SEED,
177 RAND_R_PRNG_SEED_MUST_NOT_MATCH_KEY);
178 return 0;
179 }
180 OPENSSL_cleanse(ctx->tmp_key, 16);
181 ctx->keyed = 1;
182 }
183 ctx->seeded = 1;
184 }
185 }
186 return 1;
187 }
188
fips_set_test_mode(FIPS_PRNG_CTX * ctx)189 static int fips_set_test_mode(FIPS_PRNG_CTX * ctx)
190 {
191 if (ctx->keyed) {
192 RANDerr(RAND_F_FIPS_SET_TEST_MODE, RAND_R_PRNG_KEYED);
193 return 0;
194 }
195 ctx->test_mode = 1;
196 return 1;
197 }
198
FIPS_rand_test_mode(void)199 int FIPS_rand_test_mode(void)
200 {
201 return fips_set_test_mode(&sctx);
202 }
203
FIPS_rand_set_dt(unsigned char * dt)204 int FIPS_rand_set_dt(unsigned char *dt)
205 {
206 if (!sctx.test_mode) {
207 RANDerr(RAND_F_FIPS_RAND_SET_DT, RAND_R_NOT_IN_TEST_MODE);
208 return 0;
209 }
210 memcpy(sctx.DT, dt, AES_BLOCK_LENGTH);
211 return 1;
212 }
213
fips_get_dt(FIPS_PRNG_CTX * ctx)214 static void fips_get_dt(FIPS_PRNG_CTX * ctx)
215 {
216 # ifdef OPENSSL_SYS_WIN32
217 FILETIME ft;
218 # else
219 struct timeval tv;
220 # endif
221 unsigned char *buf = ctx->DT;
222
223 # ifndef GETPID_IS_MEANINGLESS
224 unsigned long pid;
225 # endif
226
227 # ifdef OPENSSL_SYS_WIN32
228 GetSystemTimeAsFileTime(&ft);
229 buf[0] = (unsigned char)(ft.dwHighDateTime & 0xff);
230 buf[1] = (unsigned char)((ft.dwHighDateTime >> 8) & 0xff);
231 buf[2] = (unsigned char)((ft.dwHighDateTime >> 16) & 0xff);
232 buf[3] = (unsigned char)((ft.dwHighDateTime >> 24) & 0xff);
233 buf[4] = (unsigned char)(ft.dwLowDateTime & 0xff);
234 buf[5] = (unsigned char)((ft.dwLowDateTime >> 8) & 0xff);
235 buf[6] = (unsigned char)((ft.dwLowDateTime >> 16) & 0xff);
236 buf[7] = (unsigned char)((ft.dwLowDateTime >> 24) & 0xff);
237 # else
238 gettimeofday(&tv, NULL);
239 buf[0] = (unsigned char)(tv.tv_sec & 0xff);
240 buf[1] = (unsigned char)((tv.tv_sec >> 8) & 0xff);
241 buf[2] = (unsigned char)((tv.tv_sec >> 16) & 0xff);
242 buf[3] = (unsigned char)((tv.tv_sec >> 24) & 0xff);
243 buf[4] = (unsigned char)(tv.tv_usec & 0xff);
244 buf[5] = (unsigned char)((tv.tv_usec >> 8) & 0xff);
245 buf[6] = (unsigned char)((tv.tv_usec >> 16) & 0xff);
246 buf[7] = (unsigned char)((tv.tv_usec >> 24) & 0xff);
247 # endif
248 buf[8] = (unsigned char)(ctx->counter & 0xff);
249 buf[9] = (unsigned char)((ctx->counter >> 8) & 0xff);
250 buf[10] = (unsigned char)((ctx->counter >> 16) & 0xff);
251 buf[11] = (unsigned char)((ctx->counter >> 24) & 0xff);
252
253 ctx->counter++;
254
255 # ifndef GETPID_IS_MEANINGLESS
256 pid = (unsigned long)getpid();
257 buf[12] = (unsigned char)(pid & 0xff);
258 buf[13] = (unsigned char)((pid >> 8) & 0xff);
259 buf[14] = (unsigned char)((pid >> 16) & 0xff);
260 buf[15] = (unsigned char)((pid >> 24) & 0xff);
261 # endif
262 }
263
fips_rand(FIPS_PRNG_CTX * ctx,unsigned char * out,FIPS_RAND_SIZE_T outlen)264 static int fips_rand(FIPS_PRNG_CTX * ctx,
265 unsigned char *out, FIPS_RAND_SIZE_T outlen)
266 {
267 unsigned char R[AES_BLOCK_LENGTH], I[AES_BLOCK_LENGTH];
268 unsigned char tmp[AES_BLOCK_LENGTH];
269 int i;
270 if (ctx->error) {
271 RANDerr(RAND_F_FIPS_RAND, RAND_R_PRNG_ERROR);
272 return 0;
273 }
274 if (!ctx->keyed) {
275 RANDerr(RAND_F_FIPS_RAND, RAND_R_NO_KEY_SET);
276 return 0;
277 }
278 if (!ctx->seeded) {
279 RANDerr(RAND_F_FIPS_RAND, RAND_R_PRNG_NOT_SEEDED);
280 return 0;
281 }
282 for (;;) {
283 if (!ctx->test_mode)
284 fips_get_dt(ctx);
285 AES_encrypt(ctx->DT, I, &ctx->ks);
286 for (i = 0; i < AES_BLOCK_LENGTH; i++)
287 tmp[i] = I[i] ^ ctx->V[i];
288 AES_encrypt(tmp, R, &ctx->ks);
289 for (i = 0; i < AES_BLOCK_LENGTH; i++)
290 tmp[i] = R[i] ^ I[i];
291 AES_encrypt(tmp, ctx->V, &ctx->ks);
292 /* Continuous PRNG test */
293 if (ctx->second) {
294 if (fips_prng_fail)
295 memcpy(ctx->last, R, AES_BLOCK_LENGTH);
296 if (!memcmp(R, ctx->last, AES_BLOCK_LENGTH)) {
297 RANDerr(RAND_F_FIPS_RAND, RAND_R_PRNG_STUCK);
298 ctx->error = 1;
299 fips_set_selftest_fail();
300 return 0;
301 }
302 }
303 memcpy(ctx->last, R, AES_BLOCK_LENGTH);
304 if (!ctx->second) {
305 ctx->second = 1;
306 if (!ctx->test_mode)
307 continue;
308 }
309
310 if (outlen <= AES_BLOCK_LENGTH) {
311 memcpy(out, R, outlen);
312 break;
313 }
314
315 memcpy(out, R, AES_BLOCK_LENGTH);
316 out += AES_BLOCK_LENGTH;
317 outlen -= AES_BLOCK_LENGTH;
318 }
319 return 1;
320 }
321
FIPS_rand_set_key(const unsigned char * key,FIPS_RAND_SIZE_T keylen)322 int FIPS_rand_set_key(const unsigned char *key, FIPS_RAND_SIZE_T keylen)
323 {
324 int ret;
325 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
326 ret = fips_set_prng_key(&sctx, key, keylen);
327 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
328 return ret;
329 }
330
FIPS_rand_seed(const void * seed,FIPS_RAND_SIZE_T seedlen)331 int FIPS_rand_seed(const void *seed, FIPS_RAND_SIZE_T seedlen)
332 {
333 int ret;
334 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
335 ret = fips_set_prng_seed(&sctx, seed, seedlen);
336 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
337 return ret;
338 }
339
FIPS_rand_bytes(unsigned char * out,FIPS_RAND_SIZE_T count)340 int FIPS_rand_bytes(unsigned char *out, FIPS_RAND_SIZE_T count)
341 {
342 int ret;
343 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
344 ret = fips_rand(&sctx, out, count);
345 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
346 return ret;
347 }
348
FIPS_rand_status(void)349 int FIPS_rand_status(void)
350 {
351 int ret;
352 CRYPTO_r_lock(CRYPTO_LOCK_RAND);
353 ret = sctx.seeded;
354 CRYPTO_r_unlock(CRYPTO_LOCK_RAND);
355 return ret;
356 }
357
FIPS_rand_reset(void)358 void FIPS_rand_reset(void)
359 {
360 CRYPTO_w_lock(CRYPTO_LOCK_RAND);
361 fips_rand_prng_reset(&sctx);
362 CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
363 }
364
fips_do_rand_seed(const void * seed,FIPS_RAND_SIZE_T seedlen)365 static void fips_do_rand_seed(const void *seed, FIPS_RAND_SIZE_T seedlen)
366 {
367 FIPS_rand_seed(seed, seedlen);
368 }
369
fips_do_rand_add(const void * seed,FIPS_RAND_SIZE_T seedlen,double add_entropy)370 static void fips_do_rand_add(const void *seed, FIPS_RAND_SIZE_T seedlen,
371 double add_entropy)
372 {
373 FIPS_rand_seed(seed, seedlen);
374 }
375
376 static const RAND_METHOD rand_fips_meth = {
377 fips_do_rand_seed,
378 FIPS_rand_bytes,
379 FIPS_rand_reset,
380 fips_do_rand_add,
381 FIPS_rand_bytes,
382 FIPS_rand_status
383 };
384
FIPS_rand_method(void)385 const RAND_METHOD *FIPS_rand_method(void)
386 {
387 return &rand_fips_meth;
388 }
389
390 #endif
391