fips_rand.c revision 194206 
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/* If we don't define _XOPEN_SOURCE_EXTENDED, struct timeval won't
57   be defined and gettimeofday() won't be declared with strict compilers
58   like DEC C in ANSI C mode.  */
59#ifndef _XOPEN_SOURCE_EXTENDED
60#define _XOPEN_SOURCE_EXTENDED 1
61#endif
62
63#include <openssl/rand.h>
64#include <openssl/aes.h>
65#include <openssl/err.h>
66#include <openssl/fips_rand.h>
67#ifndef OPENSSL_SYS_WIN32
68#include <sys/time.h>
69#endif
70#include <assert.h>
71#ifndef OPENSSL_SYS_WIN32
72# ifdef OPENSSL_UNISTD
73#  include OPENSSL_UNISTD
74# else
75#  include <unistd.h>
76# endif
77#endif
78#include <string.h>
79#include <openssl/fips.h>
80#include "fips_locl.h"
81
82#ifdef OPENSSL_FIPS
83
84void *OPENSSL_stderr(void);
85
86#define AES_BLOCK_LENGTH	16
87
88
89/* AES FIPS PRNG implementation */
90
91typedef struct
92	{
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
108static FIPS_PRNG_CTX sctx;
109
110static int fips_prng_fail = 0;
111
112void FIPS_rng_stick(void)
113	{
114	fips_prng_fail = 1;
115	}
116
117void 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
130
131static int fips_set_prng_key(FIPS_PRNG_CTX *ctx,
132			const unsigned char *key, FIPS_RAND_SIZE_T keylen)
133	{
134	FIPS_selftest_check();
135	if (keylen != 16 && keylen != 24 && keylen != 32)
136		{
137		/* error: invalid key size */
138		return 0;
139		}
140	AES_set_encrypt_key(key, keylen << 3, &ctx->ks);
141	if (keylen == 16)
142		{
143		memcpy(ctx->tmp_key, key, 16);
144		ctx->keyed = 2;
145		}
146	else
147		ctx->keyed = 1;
148	ctx->seeded = 0;
149	ctx->second = 0;
150	return 1;
151	}
152
153static int fips_set_prng_seed(FIPS_PRNG_CTX *ctx,
154			const unsigned char *seed, FIPS_RAND_SIZE_T seedlen)
155	{
156	int i;
157	if (!ctx->keyed)
158		return 0;
159	/* In test mode seed is just supplied data */
160	if (ctx->test_mode)
161		{
162		if (seedlen != AES_BLOCK_LENGTH)
163			return 0;
164		memcpy(ctx->V, seed, AES_BLOCK_LENGTH);
165		ctx->seeded = 1;
166		return 1;
167		}
168	/* Outside test mode XOR supplied data with existing seed */
169	for (i = 0; i < seedlen; i++)
170		{
171		ctx->V[ctx->vpos++] ^= seed[i];
172		if (ctx->vpos == AES_BLOCK_LENGTH)
173			{
174			ctx->vpos = 0;
175			/* Special case if first seed and key length equals
176 			 * block size check key and seed do not match.
177 			 */
178			if (ctx->keyed == 2)
179				{
180				if (!memcmp(ctx->tmp_key, ctx->V, 16))
181					{
182					RANDerr(RAND_F_FIPS_SET_PRNG_SEED,
183						RAND_R_PRNG_SEED_MUST_NOT_MATCH_KEY);
184					return 0;
185					}
186				OPENSSL_cleanse(ctx->tmp_key, 16);
187				ctx->keyed = 1;
188				}
189			ctx->seeded = 1;
190			}
191		}
192	return 1;
193	}
194
195int fips_set_test_mode(FIPS_PRNG_CTX *ctx)
196	{
197	if (ctx->keyed)
198		{
199		RANDerr(RAND_F_FIPS_SET_TEST_MODE,RAND_R_PRNG_KEYED);
200		return 0;
201		}
202	ctx->test_mode = 1;
203	return 1;
204	}
205
206int FIPS_rand_test_mode(void)
207	{
208	return fips_set_test_mode(&sctx);
209	}
210
211int FIPS_rand_set_dt(unsigned char *dt)
212	{
213	if (!sctx.test_mode)
214		{
215		RANDerr(RAND_F_FIPS_RAND_SET_DT,RAND_R_NOT_IN_TEST_MODE);
216		return 0;
217		}
218	memcpy(sctx.DT, dt, AES_BLOCK_LENGTH);
219	return 1;
220	}
221
222static void fips_get_dt(FIPS_PRNG_CTX *ctx)
223    {
224#ifdef OPENSSL_SYS_WIN32
225	FILETIME ft;
226#else
227	struct timeval tv;
228#endif
229	unsigned char *buf = ctx->DT;
230
231#ifndef GETPID_IS_MEANINGLESS
232	unsigned long pid;
233#endif
234
235#ifdef OPENSSL_SYS_WIN32
236	GetSystemTimeAsFileTime(&ft);
237	buf[0] = (unsigned char) (ft.dwHighDateTime & 0xff);
238	buf[1] = (unsigned char) ((ft.dwHighDateTime >> 8) & 0xff);
239	buf[2] = (unsigned char) ((ft.dwHighDateTime >> 16) & 0xff);
240	buf[3] = (unsigned char) ((ft.dwHighDateTime >> 24) & 0xff);
241	buf[4] = (unsigned char) (ft.dwLowDateTime & 0xff);
242	buf[5] = (unsigned char) ((ft.dwLowDateTime >> 8) & 0xff);
243	buf[6] = (unsigned char) ((ft.dwLowDateTime >> 16) & 0xff);
244	buf[7] = (unsigned char) ((ft.dwLowDateTime >> 24) & 0xff);
245#else
246	gettimeofday(&tv,NULL);
247	buf[0] = (unsigned char) (tv.tv_sec & 0xff);
248	buf[1] = (unsigned char) ((tv.tv_sec >> 8) & 0xff);
249	buf[2] = (unsigned char) ((tv.tv_sec >> 16) & 0xff);
250	buf[3] = (unsigned char) ((tv.tv_sec >> 24) & 0xff);
251	buf[4] = (unsigned char) (tv.tv_usec & 0xff);
252	buf[5] = (unsigned char) ((tv.tv_usec >> 8) & 0xff);
253	buf[6] = (unsigned char) ((tv.tv_usec >> 16) & 0xff);
254	buf[7] = (unsigned char) ((tv.tv_usec >> 24) & 0xff);
255#endif
256	buf[8] = (unsigned char) (ctx->counter & 0xff);
257	buf[9] = (unsigned char) ((ctx->counter >> 8) & 0xff);
258	buf[10] = (unsigned char) ((ctx->counter >> 16) & 0xff);
259	buf[11] = (unsigned char) ((ctx->counter >> 24) & 0xff);
260
261	ctx->counter++;
262
263
264#ifndef GETPID_IS_MEANINGLESS
265	pid=(unsigned long)getpid();
266	buf[12] = (unsigned char) (pid & 0xff);
267	buf[13] = (unsigned char) ((pid >> 8) & 0xff);
268	buf[14] = (unsigned char) ((pid >> 16) & 0xff);
269	buf[15] = (unsigned char) ((pid >> 24) & 0xff);
270#endif
271    }
272
273static int fips_rand(FIPS_PRNG_CTX *ctx,
274			unsigned char *out, FIPS_RAND_SIZE_T outlen)
275	{
276	unsigned char R[AES_BLOCK_LENGTH], I[AES_BLOCK_LENGTH];
277	unsigned char tmp[AES_BLOCK_LENGTH];
278	int i;
279	if (ctx->error)
280		{
281		RANDerr(RAND_F_FIPS_RAND,RAND_R_PRNG_ERROR);
282		return 0;
283		}
284	if (!ctx->keyed)
285		{
286		RANDerr(RAND_F_FIPS_RAND,RAND_R_NO_KEY_SET);
287		return 0;
288		}
289	if (!ctx->seeded)
290		{
291		RANDerr(RAND_F_FIPS_RAND,RAND_R_PRNG_NOT_SEEDED);
292		return 0;
293		}
294	for (;;)
295		{
296		if (!ctx->test_mode)
297			fips_get_dt(ctx);
298		AES_encrypt(ctx->DT, I, &ctx->ks);
299		for (i = 0; i < AES_BLOCK_LENGTH; i++)
300			tmp[i] = I[i] ^ ctx->V[i];
301		AES_encrypt(tmp, R, &ctx->ks);
302		for (i = 0; i < AES_BLOCK_LENGTH; i++)
303			tmp[i] = R[i] ^ I[i];
304		AES_encrypt(tmp, ctx->V, &ctx->ks);
305		/* Continuous PRNG test */
306		if (ctx->second)
307			{
308			if (fips_prng_fail)
309				memcpy(ctx->last, R, AES_BLOCK_LENGTH);
310			if (!memcmp(R, ctx->last, AES_BLOCK_LENGTH))
311				{
312	    			RANDerr(RAND_F_FIPS_RAND,RAND_R_PRNG_STUCK);
313				ctx->error = 1;
314				fips_set_selftest_fail();
315				return 0;
316				}
317			}
318		memcpy(ctx->last, R, AES_BLOCK_LENGTH);
319		if (!ctx->second)
320			{
321			ctx->second = 1;
322			if (!ctx->test_mode)
323				continue;
324			}
325
326		if (outlen <= AES_BLOCK_LENGTH)
327			{
328			memcpy(out, R, outlen);
329			break;
330			}
331
332		memcpy(out, R, AES_BLOCK_LENGTH);
333		out += AES_BLOCK_LENGTH;
334		outlen -= AES_BLOCK_LENGTH;
335		}
336	return 1;
337	}
338
339
340int FIPS_rand_set_key(const unsigned char *key, FIPS_RAND_SIZE_T keylen)
341	{
342	int ret;
343	CRYPTO_w_lock(CRYPTO_LOCK_RAND);
344	ret = fips_set_prng_key(&sctx, key, keylen);
345	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
346	return ret;
347	}
348
349int FIPS_rand_seed(const void *seed, FIPS_RAND_SIZE_T seedlen)
350	{
351	int ret;
352	CRYPTO_w_lock(CRYPTO_LOCK_RAND);
353	ret = fips_set_prng_seed(&sctx, seed, seedlen);
354	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
355	return ret;
356	}
357
358
359int FIPS_rand_bytes(unsigned char *out, FIPS_RAND_SIZE_T count)
360	{
361	int ret;
362	CRYPTO_w_lock(CRYPTO_LOCK_RAND);
363	ret = fips_rand(&sctx, out, count);
364	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
365	return ret;
366	}
367
368int FIPS_rand_status(void)
369	{
370	int ret;
371	CRYPTO_r_lock(CRYPTO_LOCK_RAND);
372	ret = sctx.seeded;
373	CRYPTO_r_unlock(CRYPTO_LOCK_RAND);
374	return ret;
375	}
376
377void FIPS_rand_reset(void)
378	{
379	CRYPTO_w_lock(CRYPTO_LOCK_RAND);
380	fips_rand_prng_reset(&sctx);
381	CRYPTO_w_unlock(CRYPTO_LOCK_RAND);
382	}
383
384static void fips_do_rand_seed(const void *seed, FIPS_RAND_SIZE_T seedlen)
385	{
386	FIPS_rand_seed(seed, seedlen);
387	}
388
389static void fips_do_rand_add(const void *seed, FIPS_RAND_SIZE_T seedlen,
390					double add_entropy)
391	{
392	FIPS_rand_seed(seed, seedlen);
393	}
394
395static const RAND_METHOD rand_fips_meth=
396    {
397    fips_do_rand_seed,
398    FIPS_rand_bytes,
399    FIPS_rand_reset,
400    fips_do_rand_add,
401    FIPS_rand_bytes,
402    FIPS_rand_status
403    };
404
405const RAND_METHOD *FIPS_rand_method(void)
406{
407  return &rand_fips_meth;
408}
409
410#endif
411