xref: /freebsd/crypto/openssl/crypto/rand/rand_lib.c (revision f05cddf9)
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 */
75 static ENGINE *funct_ref =NULL;
76 #endif
77 static const RAND_METHOD *default_RAND_meth = NULL;
78 
79 int 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 
92 const 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
117 int 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 
138 void 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 
146 void 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 
153 void 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 
160 int 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 
168 int 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 
176 int 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 
194 static 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 
211 static 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 
224 static 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 
238 static 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 
245 static 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 
258 static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE;
259 static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS;
260 
261 void RAND_set_fips_drbg_type(int type, int flags)
262 	{
263 	fips_drbg_type = type;
264 	fips_drbg_flags = flags;
265 	}
266 
267 int RAND_init_fips(void)
268 	{
269 	DRBG_CTX *dctx;
270 	size_t plen;
271 	unsigned char pers[32], *p;
272 	dctx = FIPS_get_default_drbg();
273         if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0)
274 		{
275 		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG);
276 		return 0;
277 		}
278 
279         FIPS_drbg_set_callbacks(dctx,
280 				drbg_get_entropy, drbg_free_entropy, 20,
281 				drbg_get_entropy, drbg_free_entropy);
282 	FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
283 					drbg_rand_seed, drbg_rand_add);
284 	/* Personalisation string: a string followed by date time vector */
285 	strcpy((char *)pers, "OpenSSL DRBG2.0");
286 	plen = drbg_get_adin(dctx, &p);
287 	memcpy(pers + 16, p, plen);
288 
289         if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0)
290 		{
291 		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG);
292 		return 0;
293 		}
294         FIPS_rand_set_method(FIPS_drbg_method());
295 	return 1;
296 	}
297 
298 #endif
299