rand_lib.c revision 111147 
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
67#ifndef OPENSSL_NO_ENGINE
68/* non-NULL if default_RAND_meth is ENGINE-provided */
69static ENGINE *funct_ref =NULL;
70#endif
71static const RAND_METHOD *default_RAND_meth = NULL;
72
73int RAND_set_rand_method(const RAND_METHOD *meth)
74	{
75#ifndef OPENSSL_NO_ENGINE
76	if(funct_ref)
77		{
78		ENGINE_finish(funct_ref);
79		funct_ref = NULL;
80		}
81#endif
82	default_RAND_meth = meth;
83	return 1;
84	}
85
86const RAND_METHOD *RAND_get_rand_method(void)
87	{
88	if (!default_RAND_meth)
89		{
90#ifndef OPENSSL_NO_ENGINE
91		ENGINE *e = ENGINE_get_default_RAND();
92		if(e)
93			{
94			default_RAND_meth = ENGINE_get_RAND(e);
95			if(!default_RAND_meth)
96				{
97				ENGINE_finish(e);
98				e = NULL;
99				}
100			}
101		if(e)
102			funct_ref = e;
103		else
104#endif
105			default_RAND_meth = RAND_SSLeay();
106		}
107	return default_RAND_meth;
108	}
109
110#ifndef OPENSSL_NO_ENGINE
111int RAND_set_rand_engine(ENGINE *engine)
112	{
113	const RAND_METHOD *tmp_meth = NULL;
114	if(engine)
115		{
116		if(!ENGINE_init(engine))
117			return 0;
118		tmp_meth = ENGINE_get_RAND(engine);
119		if(!tmp_meth)
120			{
121			ENGINE_finish(engine);
122			return 0;
123			}
124		}
125	/* This function releases any prior ENGINE so call it first */
126	RAND_set_rand_method(tmp_meth);
127	funct_ref = engine;
128	return 1;
129	}
130#endif
131
132void RAND_cleanup(void)
133	{
134	const RAND_METHOD *meth = RAND_get_rand_method();
135	if (meth && meth->cleanup)
136		meth->cleanup();
137	RAND_set_rand_method(NULL);
138	}
139
140void RAND_seed(const void *buf, int num)
141	{
142	const RAND_METHOD *meth = RAND_get_rand_method();
143	if (meth && meth->seed)
144		meth->seed(buf,num);
145	}
146
147void RAND_add(const void *buf, int num, double entropy)
148	{
149	const RAND_METHOD *meth = RAND_get_rand_method();
150	if (meth && meth->add)
151		meth->add(buf,num,entropy);
152	}
153
154int RAND_bytes(unsigned char *buf, int num)
155	{
156	const RAND_METHOD *meth = RAND_get_rand_method();
157	if (meth && meth->bytes)
158		return meth->bytes(buf,num);
159	return(-1);
160	}
161
162int RAND_pseudo_bytes(unsigned char *buf, int num)
163	{
164	const RAND_METHOD *meth = RAND_get_rand_method();
165	if (meth && meth->pseudorand)
166		return meth->pseudorand(buf,num);
167	return(-1);
168	}
169
170int RAND_status(void)
171	{
172	const RAND_METHOD *meth = RAND_get_rand_method();
173	if (meth && meth->status)
174		return meth->status();
175	return 0;
176	}
177