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      1 /* crypto/rand/rand_lib.c */
      2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      3  * All rights reserved.
      4  *
      5  * This package is an SSL implementation written
      6  * by Eric Young (eay (at) 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 (at) 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 (at) 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 (at) 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