xref: /openbsd-src/lib/libcrypto/rand/rand_lib.c (revision 6d388760ec629bdebe2f200913a35899243a7957)
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 #ifndef OPENSSL_NO_ENGINE
64 #include <openssl/engine.h>
65 #endif
66 #include <openssl/fips.h>
67 #include <openssl/fips_rand.h>
68 
69 #ifndef OPENSSL_NO_ENGINE
70 /* non-NULL if default_RAND_meth is ENGINE-provided */
71 static ENGINE *funct_ref =NULL;
72 #endif
73 static const RAND_METHOD *default_RAND_meth = NULL;
74 
75 int RAND_set_rand_method(const RAND_METHOD *meth)
76 	{
77 #ifndef OPENSSL_NO_ENGINE
78 	if(funct_ref)
79 		{
80 		ENGINE_finish(funct_ref);
81 		funct_ref = NULL;
82 		}
83 #endif
84 	default_RAND_meth = meth;
85 	return 1;
86 	}
87 
88 const RAND_METHOD *RAND_get_rand_method(void)
89 	{
90 	if (!default_RAND_meth)
91 		{
92 #ifndef OPENSSL_NO_ENGINE
93 		ENGINE *e = ENGINE_get_default_RAND();
94 		if(e)
95 			{
96 			default_RAND_meth = ENGINE_get_RAND(e);
97 			if(!default_RAND_meth)
98 				{
99 				ENGINE_finish(e);
100 				e = NULL;
101 				}
102 			}
103 		if(e)
104 			funct_ref = e;
105 		else
106 #endif
107 #ifdef OPENSSL_FIPS
108 			if(FIPS_mode())
109 				default_RAND_meth=FIPS_rand_method();
110 			else
111 #endif
112 				default_RAND_meth = RAND_SSLeay();
113 		}
114 
115 #ifdef OPENSSL_FIPS
116 	if(FIPS_mode()
117 		&& default_RAND_meth != FIPS_rand_check())
118 	    {
119 	    RANDerr(RAND_F_RAND_GET_RAND_METHOD,RAND_R_NON_FIPS_METHOD);
120 	    return 0;
121 	    }
122 #endif
123 	return default_RAND_meth;
124 	}
125 
126 #ifndef OPENSSL_NO_ENGINE
127 int RAND_set_rand_engine(ENGINE *engine)
128 	{
129 	const RAND_METHOD *tmp_meth = NULL;
130 	if(engine)
131 		{
132 		if(!ENGINE_init(engine))
133 			return 0;
134 		tmp_meth = ENGINE_get_RAND(engine);
135 		if(!tmp_meth)
136 			{
137 			ENGINE_finish(engine);
138 			return 0;
139 			}
140 		}
141 	/* This function releases any prior ENGINE so call it first */
142 	RAND_set_rand_method(tmp_meth);
143 	funct_ref = engine;
144 	return 1;
145 	}
146 #endif
147 
148 void RAND_cleanup(void)
149 	{
150 	const RAND_METHOD *meth = RAND_get_rand_method();
151 	if (meth && meth->cleanup)
152 		meth->cleanup();
153 	RAND_set_rand_method(NULL);
154 	}
155 
156 void RAND_seed(const void *buf, int num)
157 	{
158 	const RAND_METHOD *meth = RAND_get_rand_method();
159 	if (meth && meth->seed)
160 		meth->seed(buf,num);
161 	}
162 
163 void RAND_add(const void *buf, int num, double entropy)
164 	{
165 	const RAND_METHOD *meth = RAND_get_rand_method();
166 	if (meth && meth->add)
167 		meth->add(buf,num,entropy);
168 	}
169 
170 int RAND_bytes(unsigned char *buf, int num)
171 	{
172 	const RAND_METHOD *meth = RAND_get_rand_method();
173 	if (meth && meth->bytes)
174 		return meth->bytes(buf,num);
175 	return(-1);
176 	}
177 
178 int RAND_pseudo_bytes(unsigned char *buf, int num)
179 	{
180 	const RAND_METHOD *meth = RAND_get_rand_method();
181 	if (meth && meth->pseudorand)
182 		return meth->pseudorand(buf,num);
183 	return(-1);
184 	}
185 
186 int RAND_status(void)
187 	{
188 	const RAND_METHOD *meth = RAND_get_rand_method();
189 	if (meth && meth->status)
190 		return meth->status();
191 	return 0;
192 	}
193