rand_lib.c revision 264331 
1/* crypto/rand/rand_lib.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59#include <stdio.h>
60#include <time.h>
61#include "cryptlib.h"
62#include <openssl/rand.h>
63
64#ifndef OPENSSL_NO_ENGINE
65#include <openssl/engine.h>
66#endif
67
68#ifdef OPENSSL_FIPS
69#include <openssl/fips.h>
70#include <openssl/fips_rand.h>
71#endif
72
73#ifndef OPENSSL_NO_ENGINE
74/* non-NULL if default_RAND_meth is ENGINE-provided */
75static ENGINE *funct_ref =NULL;
76#endif
77static const RAND_METHOD *default_RAND_meth = NULL;
78
79int RAND_set_rand_method(const RAND_METHOD *meth)
80	{
81#ifndef OPENSSL_NO_ENGINE
82	if(funct_ref)
83		{
84		ENGINE_finish(funct_ref);
85		funct_ref = NULL;
86		}
87#endif
88	default_RAND_meth = meth;
89	return 1;
90	}
91
92const RAND_METHOD *RAND_get_rand_method(void)
93	{
94	if (!default_RAND_meth)
95		{
96#ifndef OPENSSL_NO_ENGINE
97		ENGINE *e = ENGINE_get_default_RAND();
98		if(e)
99			{
100			default_RAND_meth = ENGINE_get_RAND(e);
101			if(!default_RAND_meth)
102				{
103				ENGINE_finish(e);
104				e = NULL;
105				}
106			}
107		if(e)
108			funct_ref = e;
109		else
110#endif
111			default_RAND_meth = RAND_SSLeay();
112		}
113	return default_RAND_meth;
114	}
115
116#ifndef OPENSSL_NO_ENGINE
117int RAND_set_rand_engine(ENGINE *engine)
118	{
119	const RAND_METHOD *tmp_meth = NULL;
120	if(engine)
121		{
122		if(!ENGINE_init(engine))
123			return 0;
124		tmp_meth = ENGINE_get_RAND(engine);
125		if(!tmp_meth)
126			{
127			ENGINE_finish(engine);
128			return 0;
129			}
130		}
131	/* This function releases any prior ENGINE so call it first */
132	RAND_set_rand_method(tmp_meth);
133	funct_ref = engine;
134	return 1;
135	}
136#endif
137
138void RAND_cleanup(void)
139	{
140	const RAND_METHOD *meth = RAND_get_rand_method();
141	if (meth && meth->cleanup)
142		meth->cleanup();
143	RAND_set_rand_method(NULL);
144	}
145
146void RAND_seed(const void *buf, int num)
147	{
148	const RAND_METHOD *meth = RAND_get_rand_method();
149	if (meth && meth->seed)
150		meth->seed(buf,num);
151	}
152
153void RAND_add(const void *buf, int num, double entropy)
154	{
155	const RAND_METHOD *meth = RAND_get_rand_method();
156	if (meth && meth->add)
157		meth->add(buf,num,entropy);
158	}
159
160int RAND_bytes(unsigned char *buf, int num)
161	{
162	const RAND_METHOD *meth = RAND_get_rand_method();
163	if (meth && meth->bytes)
164		return meth->bytes(buf,num);
165	return(-1);
166	}
167
168int RAND_pseudo_bytes(unsigned char *buf, int num)
169	{
170	const RAND_METHOD *meth = RAND_get_rand_method();
171	if (meth && meth->pseudorand)
172		return meth->pseudorand(buf,num);
173	return(-1);
174	}
175
176int RAND_status(void)
177	{
178	const RAND_METHOD *meth = RAND_get_rand_method();
179	if (meth && meth->status)
180		return meth->status();
181	return 0;
182	}
183
184#ifdef OPENSSL_FIPS
185
186/* FIPS DRBG initialisation code. This sets up the DRBG for use by the
187 * rest of OpenSSL.
188 */
189
190/* Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather
191 * entropy internally through RAND_poll().
192 */
193
194static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout,
195                                int entropy, size_t min_len, size_t max_len)
196        {
197	/* Round up request to multiple of block size */
198	min_len = ((min_len + 19) / 20) * 20;
199	*pout = OPENSSL_malloc(min_len);
200	if (!*pout)
201		return 0;
202	if (RAND_SSLeay()->bytes(*pout, min_len) <= 0)
203		{
204		OPENSSL_free(*pout);
205		*pout = NULL;
206		return 0;
207		}
208        return min_len;
209        }
210
211static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
212	{
213	if (out)
214		{
215		OPENSSL_cleanse(out, olen);
216		OPENSSL_free(out);
217		}
218	}
219
220/* Set "additional input" when generating random data. This uses the
221 * current PID, a time value and a counter.
222 */
223
224static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout)
225    	{
226	/* Use of static variables is OK as this happens under a lock */
227	static unsigned char buf[16];
228	static unsigned long counter;
229	FIPS_get_timevec(buf, &counter);
230	*pout = buf;
231	return sizeof(buf);
232	}
233
234/* RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is
235 * correctly seeded by RAND_poll().
236 */
237
238static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen,
239				double entropy)
240	{
241	RAND_SSLeay()->add(in, inlen, entropy);
242	return 1;
243	}
244
245static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
246	{
247	RAND_SSLeay()->seed(in, inlen);
248	return 1;
249	}
250
251#ifndef OPENSSL_DRBG_DEFAULT_TYPE
252#define OPENSSL_DRBG_DEFAULT_TYPE	NID_aes_256_ctr
253#endif
254#ifndef OPENSSL_DRBG_DEFAULT_FLAGS
255#define OPENSSL_DRBG_DEFAULT_FLAGS	DRBG_FLAG_CTR_USE_DF
256#endif
257
258static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE;
259static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS;
260
261void RAND_set_fips_drbg_type(int type, int flags)
262	{
263	fips_drbg_type = type;
264	fips_drbg_flags = flags;
265	}
266
267int RAND_init_fips(void)
268	{
269	DRBG_CTX *dctx;
270	size_t plen;
271	unsigned char pers[32], *p;
272#ifndef OPENSSL_ALLOW_DUAL_EC_DRBG
273	if (fips_drbg_type >> 16)
274		{
275		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_DUAL_EC_DRBG_DISABLED);
276		return 0;
277		}
278#endif
279
280	dctx = FIPS_get_default_drbg();
281        if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0)
282		{
283		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG);
284		return 0;
285		}
286
287        FIPS_drbg_set_callbacks(dctx,
288				drbg_get_entropy, drbg_free_entropy, 20,
289				drbg_get_entropy, drbg_free_entropy);
290	FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
291					drbg_rand_seed, drbg_rand_add);
292	/* Personalisation string: a string followed by date time vector */
293	strcpy((char *)pers, "OpenSSL DRBG2.0");
294	plen = drbg_get_adin(dctx, &p);
295	memcpy(pers + 16, p, plen);
296
297        if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0)
298		{
299		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG);
300		return 0;
301		}
302        FIPS_rand_set_method(FIPS_drbg_method());
303	return 1;
304	}
305
306#endif
307