source: trunk/sys/libcrypto/others/rand_lib.c @ 27

/* crypto/rand/rand_lib.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include <time.h>
#include "cryptlib.h"
#include <openssl/rand.h>
#include "rand_lcl.h"
#ifdef OPENSSL_FIPS
#include <openssl/fips.h>
#include <openssl/fips_rand.h>
#endif

#ifndef OPENSSL_NO_ENGINE
#include <openssl/engine.h>
#endif

static const RAND_METHOD *default_RAND_meth = NULL;

#ifdef OPENSSL_FIPS

static int fips_RAND_set_rand_method(const RAND_METHOD *meth,
                                        const RAND_METHOD **pmeth)
        {
        *pmeth = meth;
        return 1;
        }

static const RAND_METHOD *fips_RAND_get_rand_method(const RAND_METHOD **pmeth)
        {
        if (!*pmeth)
                {
                if(FIPS_mode())
                        *pmeth=FIPS_rand_method();
                else
                        *pmeth = RAND_SSLeay();
                }

        if(FIPS_mode()
                && *pmeth != FIPS_rand_check())
            {
            RANDerr(RAND_F_FIPS_RAND_GET_RAND_METHOD,RAND_R_NON_FIPS_METHOD);
            return 0;
            }

        return *pmeth;
        }

static int (*RAND_set_rand_method_func)(const RAND_METHOD *meth,
                                                const RAND_METHOD **pmeth)
        = fips_RAND_set_rand_method;
static const RAND_METHOD *(*RAND_get_rand_method_func)
                                                (const RAND_METHOD **pmeth)
        = fips_RAND_get_rand_method;

#ifndef OPENSSL_NO_ENGINE
void int_RAND_set_callbacks(
        int (*set_rand_func)(const RAND_METHOD *meth,
                                                const RAND_METHOD **pmeth),
        const RAND_METHOD *(*get_rand_func)
                                                (const RAND_METHOD **pmeth))
        {
        RAND_set_rand_method_func = set_rand_func;
        RAND_get_rand_method_func = get_rand_func;
        }
#endif

int RAND_set_rand_method(const RAND_METHOD *meth)
        {
        return RAND_set_rand_method_func(meth, &default_RAND_meth);
        }

const RAND_METHOD *RAND_get_rand_method(void)
        {
        return RAND_get_rand_method_func(&default_RAND_meth);
        }

#else

#ifndef OPENSSL_NO_ENGINE
/* non-NULL if default_RAND_meth is ENGINE-provided */
static ENGINE *funct_ref =NULL;
#endif

int RAND_set_rand_method(const RAND_METHOD *meth)
        {
#ifndef OPENSSL_NO_ENGINE
        if(funct_ref)
                {
                ENGINE_finish(funct_ref);
                funct_ref = NULL;
                }
#endif
        default_RAND_meth = meth;
        return 1;
        }

const RAND_METHOD *RAND_get_rand_method(void)
        {
        if (!default_RAND_meth)
                {
#ifndef OPENSSL_NO_ENGINE
                ENGINE *e = ENGINE_get_default_RAND();
                if(e)
                        {
                        default_RAND_meth = ENGINE_get_RAND(e);
                        if(!default_RAND_meth)
                                {
                                ENGINE_finish(e);
                                e = NULL;
                                }
                        }
                if(e)
                        funct_ref = e;
                else
#endif
                        default_RAND_meth = RAND_SSLeay();
                }
        return default_RAND_meth;
        }

#ifndef OPENSSL_NO_ENGINE
int RAND_set_rand_engine(ENGINE *engine)
        {
        const RAND_METHOD *tmp_meth = NULL;
        if(engine)
                {
                if(!ENGINE_init(engine))
                        return 0;
                tmp_meth = ENGINE_get_RAND(engine);
                if(!tmp_meth)
                        {
                        ENGINE_finish(engine);
                        return 0;
                        }
                }
        /* This function releases any prior ENGINE so call it first */
        RAND_set_rand_method(tmp_meth);
        funct_ref = engine;
        return 1;
        }
#endif

#endif

void RAND_cleanup(void)
        {
        const RAND_METHOD *meth = RAND_get_rand_method();
        if (meth && meth->cleanup)
                meth->cleanup();
        RAND_set_rand_method(NULL);
        }

void RAND_seed(const void *buf, int num)
        {
        const RAND_METHOD *meth = RAND_get_rand_method();
        if (meth && meth->seed)
                meth->seed(buf,num);
        }

void RAND_add(const void *buf, int num, double entropy)
        {
        const RAND_METHOD *meth = RAND_get_rand_method();
        if (meth && meth->add)
                meth->add(buf,num,entropy);
        }

int RAND_bytes(unsigned char *buf, int num)
        {
        const RAND_METHOD *meth = RAND_get_rand_method();
        if (meth && meth->bytes)
                return meth->bytes(buf,num);
        return(-1);
        }

int RAND_pseudo_bytes(unsigned char *buf, int num)
        {
        const RAND_METHOD *meth = RAND_get_rand_method();
        if (meth && meth->pseudorand)
                return meth->pseudorand(buf,num);
        return(-1);
        }

int RAND_status(void)
        {
        const RAND_METHOD *meth = RAND_get_rand_method();
        if (meth && meth->status)
                return meth->status();
        return 0;
        }