rand_lib.c revision 296465 
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#include "rand_lcl.h"
64#ifdef OPENSSL_FIPS
65# include <openssl/fips.h>
66# include <openssl/fips_rand.h>
67#endif
68
69#ifndef OPENSSL_NO_ENGINE
70# include <openssl/engine.h>
71#endif
72
73static const RAND_METHOD *default_RAND_meth = NULL;
74
75#ifdef OPENSSL_FIPS
76
77static int fips_RAND_set_rand_method(const RAND_METHOD *meth,
78                                     const RAND_METHOD **pmeth)
79{
80    *pmeth = meth;
81    return 1;
82}
83
84static const RAND_METHOD *fips_RAND_get_rand_method(const RAND_METHOD **pmeth)
85{
86    if (!*pmeth) {
87        if (FIPS_mode())
88            *pmeth = FIPS_rand_method();
89        else
90            *pmeth = RAND_SSLeay();
91    }
92
93    if (FIPS_mode()
94        && *pmeth != FIPS_rand_check()) {
95        RANDerr(RAND_F_FIPS_RAND_GET_RAND_METHOD, RAND_R_NON_FIPS_METHOD);
96        return 0;
97    }
98
99    return *pmeth;
100}
101
102static int (*RAND_set_rand_method_func) (const RAND_METHOD *meth,
103                                         const RAND_METHOD **pmeth)
104    = fips_RAND_set_rand_method;
105static const RAND_METHOD *(*RAND_get_rand_method_func)
106 (const RAND_METHOD **pmeth)
107    = fips_RAND_get_rand_method;
108
109# ifndef OPENSSL_NO_ENGINE
110void int_RAND_set_callbacks(int (*set_rand_func) (const RAND_METHOD *meth,
111                                                  const RAND_METHOD **pmeth),
112                            const RAND_METHOD *(*get_rand_func)
113                             (const RAND_METHOD **pmeth))
114{
115    RAND_set_rand_method_func = set_rand_func;
116    RAND_get_rand_method_func = get_rand_func;
117}
118# endif
119
120int RAND_set_rand_method(const RAND_METHOD *meth)
121{
122    return RAND_set_rand_method_func(meth, &default_RAND_meth);
123}
124
125const RAND_METHOD *RAND_get_rand_method(void)
126{
127    return RAND_get_rand_method_func(&default_RAND_meth);
128}
129
130#else
131
132# ifndef OPENSSL_NO_ENGINE
133/* non-NULL if default_RAND_meth is ENGINE-provided */
134static ENGINE *funct_ref = NULL;
135# endif
136
137int RAND_set_rand_method(const RAND_METHOD *meth)
138{
139# ifndef OPENSSL_NO_ENGINE
140    if (funct_ref) {
141        ENGINE_finish(funct_ref);
142        funct_ref = NULL;
143    }
144# endif
145    default_RAND_meth = meth;
146    return 1;
147}
148
149const RAND_METHOD *RAND_get_rand_method(void)
150{
151    if (!default_RAND_meth) {
152# ifndef OPENSSL_NO_ENGINE
153        ENGINE *e = ENGINE_get_default_RAND();
154        if (e) {
155            default_RAND_meth = ENGINE_get_RAND(e);
156            if (!default_RAND_meth) {
157                ENGINE_finish(e);
158                e = NULL;
159            }
160        }
161        if (e)
162            funct_ref = e;
163        else
164# endif
165            default_RAND_meth = RAND_SSLeay();
166    }
167    return default_RAND_meth;
168}
169
170# ifndef OPENSSL_NO_ENGINE
171int RAND_set_rand_engine(ENGINE *engine)
172{
173    const RAND_METHOD *tmp_meth = NULL;
174    if (engine) {
175        if (!ENGINE_init(engine))
176            return 0;
177        tmp_meth = ENGINE_get_RAND(engine);
178        if (!tmp_meth) {
179            ENGINE_finish(engine);
180            return 0;
181        }
182    }
183    /* This function releases any prior ENGINE so call it first */
184    RAND_set_rand_method(tmp_meth);
185    funct_ref = engine;
186    return 1;
187}
188# endif
189
190#endif
191
192void RAND_cleanup(void)
193{
194    const RAND_METHOD *meth = RAND_get_rand_method();
195    if (meth && meth->cleanup)
196        meth->cleanup();
197    RAND_set_rand_method(NULL);
198}
199
200void RAND_seed(const void *buf, int num)
201{
202    const RAND_METHOD *meth = RAND_get_rand_method();
203    if (meth && meth->seed)
204        meth->seed(buf, num);
205}
206
207void RAND_add(const void *buf, int num, double entropy)
208{
209    const RAND_METHOD *meth = RAND_get_rand_method();
210    if (meth && meth->add)
211        meth->add(buf, num, entropy);
212}
213
214int RAND_bytes(unsigned char *buf, int num)
215{
216    const RAND_METHOD *meth = RAND_get_rand_method();
217    if (meth && meth->bytes)
218        return meth->bytes(buf, num);
219    return (-1);
220}
221
222int RAND_pseudo_bytes(unsigned char *buf, int num)
223{
224    const RAND_METHOD *meth = RAND_get_rand_method();
225    if (meth && meth->pseudorand)
226        return meth->pseudorand(buf, num);
227    return (-1);
228}
229
230int RAND_status(void)
231{
232    const RAND_METHOD *meth = RAND_get_rand_method();
233    if (meth && meth->status)
234        return meth->status();
235    return 0;
236}
237