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#include "rand_lcl.h"
72#endif
73
74#ifndef OPENSSL_NO_ENGINE
75/* non-NULL if default_RAND_meth is ENGINE-provided */
76static ENGINE *funct_ref =NULL;
77#endif
78static const RAND_METHOD *default_RAND_meth = NULL;
79
80int RAND_set_rand_method(const RAND_METHOD *meth)
81	{
82#ifndef OPENSSL_NO_ENGINE
83	if(funct_ref)
84		{
85		ENGINE_finish(funct_ref);
86		funct_ref = NULL;
87		}
88#endif
89	default_RAND_meth = meth;
90	return 1;
91	}
92
93const RAND_METHOD *RAND_get_rand_method(void)
94	{
95	if (!default_RAND_meth)
96		{
97#ifndef OPENSSL_NO_ENGINE
98		ENGINE *e = ENGINE_get_default_RAND();
99		if(e)
100			{
101			default_RAND_meth = ENGINE_get_RAND(e);
102			if(!default_RAND_meth)
103				{
104				ENGINE_finish(e);
105				e = NULL;
106				}
107			}
108		if(e)
109			funct_ref = e;
110		else
111#endif
112			default_RAND_meth = RAND_SSLeay();
113		}
114	return default_RAND_meth;
115	}
116
117#ifndef OPENSSL_NO_ENGINE
118int RAND_set_rand_engine(ENGINE *engine)
119	{
120	const RAND_METHOD *tmp_meth = NULL;
121	if(engine)
122		{
123		if(!ENGINE_init(engine))
124			return 0;
125		tmp_meth = ENGINE_get_RAND(engine);
126		if(!tmp_meth)
127			{
128			ENGINE_finish(engine);
129			return 0;
130			}
131		}
132	/* This function releases any prior ENGINE so call it first */
133	RAND_set_rand_method(tmp_meth);
134	funct_ref = engine;
135	return 1;
136	}
137#endif
138
139void RAND_cleanup(void)
140	{
141	const RAND_METHOD *meth = RAND_get_rand_method();
142	if (meth && meth->cleanup)
143		meth->cleanup();
144	RAND_set_rand_method(NULL);
145	}
146
147void RAND_seed(const void *buf, int num)
148	{
149	const RAND_METHOD *meth = RAND_get_rand_method();
150	if (meth && meth->seed)
151		meth->seed(buf,num);
152	}
153
154void RAND_add(const void *buf, int num, double entropy)
155	{
156	const RAND_METHOD *meth = RAND_get_rand_method();
157	if (meth && meth->add)
158		meth->add(buf,num,entropy);
159	}
160
161int RAND_bytes(unsigned char *buf, int num)
162	{
163	const RAND_METHOD *meth = RAND_get_rand_method();
164	if (meth && meth->bytes)
165		return meth->bytes(buf,num);
166	return(-1);
167	}
168
169int RAND_pseudo_bytes(unsigned char *buf, int num)
170	{
171	const RAND_METHOD *meth = RAND_get_rand_method();
172	if (meth && meth->pseudorand)
173		return meth->pseudorand(buf,num);
174	return(-1);
175	}
176
177int RAND_status(void)
178	{
179	const RAND_METHOD *meth = RAND_get_rand_method();
180	if (meth && meth->status)
181		return meth->status();
182	return 0;
183	}
184
185#ifdef OPENSSL_FIPS
186
187/* FIPS DRBG initialisation code. This sets up the DRBG for use by the
188 * rest of OpenSSL.
189 */
190
191/* Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather
192 * entropy internally through RAND_poll().
193 */
194
195static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout,
196                                int entropy, size_t min_len, size_t max_len)
197        {
198	/* Round up request to multiple of block size */
199	min_len = ((min_len + 19) / 20) * 20;
200	*pout = OPENSSL_malloc(min_len);
201	if (!*pout)
202		return 0;
203	if (ssleay_rand_bytes(*pout, min_len, 0, 0) <= 0)
204		{
205		OPENSSL_free(*pout);
206		*pout = NULL;
207		return 0;
208		}
209        return min_len;
210        }
211
212static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
213	{
214	if (out)
215		{
216		OPENSSL_cleanse(out, olen);
217		OPENSSL_free(out);
218		}
219	}
220
221/* Set "additional input" when generating random data. This uses the
222 * current PID, a time value and a counter.
223 */
224
225static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout)
226    	{
227	/* Use of static variables is OK as this happens under a lock */
228	static unsigned char buf[16];
229	static unsigned long counter;
230	FIPS_get_timevec(buf, &counter);
231	*pout = buf;
232	return sizeof(buf);
233	}
234
235/* RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is
236 * correctly seeded by RAND_poll().
237 */
238
239static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen,
240				double entropy)
241	{
242	RAND_SSLeay()->add(in, inlen, entropy);
243	return 1;
244	}
245
246static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
247	{
248	RAND_SSLeay()->seed(in, inlen);
249	return 1;
250	}
251
252#ifndef OPENSSL_DRBG_DEFAULT_TYPE
253#define OPENSSL_DRBG_DEFAULT_TYPE	NID_aes_256_ctr
254#endif
255#ifndef OPENSSL_DRBG_DEFAULT_FLAGS
256#define OPENSSL_DRBG_DEFAULT_FLAGS	DRBG_FLAG_CTR_USE_DF
257#endif
258
259static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE;
260static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS;
261
262void RAND_set_fips_drbg_type(int type, int flags)
263	{
264	fips_drbg_type = type;
265	fips_drbg_flags = flags;
266	}
267
268int RAND_init_fips(void)
269	{
270	DRBG_CTX *dctx;
271	size_t plen;
272	unsigned char pers[32], *p;
273#ifndef OPENSSL_ALLOW_DUAL_EC_DRBG
274	if (fips_drbg_type >> 16)
275		{
276		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_DUAL_EC_DRBG_DISABLED);
277		return 0;
278		}
279#endif
280
281	dctx = FIPS_get_default_drbg();
282        if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0)
283		{
284		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG);
285		return 0;
286		}
287
288        FIPS_drbg_set_callbacks(dctx,
289				drbg_get_entropy, drbg_free_entropy, 20,
290				drbg_get_entropy, drbg_free_entropy);
291	FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
292					drbg_rand_seed, drbg_rand_add);
293	/* Personalisation string: a string followed by date time vector */
294	strcpy((char *)pers, "OpenSSL DRBG2.0");
295	plen = drbg_get_adin(dctx, &p);
296	memcpy(pers + 16, p, plen);
297
298        if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0)
299		{
300		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG);
301		return 0;
302		}
303        FIPS_rand_set_method(FIPS_drbg_method());
304	return 1;
305	}
306
307#endif
308