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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 #include "rand_lcl.h"
     72 #endif
     73 
     74 #ifndef OPENSSL_NO_ENGINE
     75 /* non-NULL if default_RAND_meth is ENGINE-provided */
     76 static ENGINE *funct_ref =NULL;
     77 #endif
     78 static const RAND_METHOD *default_RAND_meth = NULL;
     79 
     80 int RAND_set_rand_method(const RAND_METHOD *meth)
     81 	{
     82 #ifndef OPENSSL_NO_ENGINE
     83 	if(funct_ref)
     84 		{
     85 		ENGINE_finish(funct_ref);
     86 		funct_ref = NULL;
     87 		}
     88 #endif
     89 	default_RAND_meth = meth;
     90 	return 1;
     91 	}
     92 
     93 const RAND_METHOD *RAND_get_rand_method(void)
     94 	{
     95 	if (!default_RAND_meth)
     96 		{
     97 #ifndef OPENSSL_NO_ENGINE
     98 		ENGINE *e = ENGINE_get_default_RAND();
     99 		if(e)
    100 			{
    101 			default_RAND_meth = ENGINE_get_RAND(e);
    102 			if(!default_RAND_meth)
    103 				{
    104 				ENGINE_finish(e);
    105 				e = NULL;
    106 				}
    107 			}
    108 		if(e)
    109 			funct_ref = e;
    110 		else
    111 #endif
    112 			default_RAND_meth = RAND_SSLeay();
    113 		}
    114 	return default_RAND_meth;
    115 	}
    116 
    117 #ifndef OPENSSL_NO_ENGINE
    118 int RAND_set_rand_engine(ENGINE *engine)
    119 	{
    120 	const RAND_METHOD *tmp_meth = NULL;
    121 	if(engine)
    122 		{
    123 		if(!ENGINE_init(engine))
    124 			return 0;
    125 		tmp_meth = ENGINE_get_RAND(engine);
    126 		if(!tmp_meth)
    127 			{
    128 			ENGINE_finish(engine);
    129 			return 0;
    130 			}
    131 		}
    132 	/* This function releases any prior ENGINE so call it first */
    133 	RAND_set_rand_method(tmp_meth);
    134 	funct_ref = engine;
    135 	return 1;
    136 	}
    137 #endif
    138 
    139 void RAND_cleanup(void)
    140 	{
    141 	const RAND_METHOD *meth = RAND_get_rand_method();
    142 	if (meth && meth->cleanup)
    143 		meth->cleanup();
    144 	RAND_set_rand_method(NULL);
    145 	}
    146 
    147 void RAND_seed(const void *buf, int num)
    148 	{
    149 	const RAND_METHOD *meth = RAND_get_rand_method();
    150 	if (meth && meth->seed)
    151 		meth->seed(buf,num);
    152 	}
    153 
    154 void RAND_add(const void *buf, int num, double entropy)
    155 	{
    156 	const RAND_METHOD *meth = RAND_get_rand_method();
    157 	if (meth && meth->add)
    158 		meth->add(buf,num,entropy);
    159 	}
    160 
    161 int RAND_bytes(unsigned char *buf, int num)
    162 	{
    163 	const RAND_METHOD *meth = RAND_get_rand_method();
    164 	if (meth && meth->bytes)
    165 		return meth->bytes(buf,num);
    166 	return(-1);
    167 	}
    168 
    169 int RAND_pseudo_bytes(unsigned char *buf, int num)
    170 	{
    171 	const RAND_METHOD *meth = RAND_get_rand_method();
    172 	if (meth && meth->pseudorand)
    173 		return meth->pseudorand(buf,num);
    174 	return(-1);
    175 	}
    176 
    177 int RAND_status(void)
    178 	{
    179 	const RAND_METHOD *meth = RAND_get_rand_method();
    180 	if (meth && meth->status)
    181 		return meth->status();
    182 	return 0;
    183 	}
    184 
    185 #ifdef OPENSSL_FIPS
    186 
    187 /* FIPS DRBG initialisation code. This sets up the DRBG for use by the
    188  * rest of OpenSSL.
    189  */
    190 
    191 /* Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather
    192  * entropy internally through RAND_poll().
    193  */
    194 
    195 static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout,
    196                                 int entropy, size_t min_len, size_t max_len)
    197         {
    198 	/* Round up request to multiple of block size */
    199 	min_len = ((min_len + 19) / 20) * 20;
    200 	*pout = OPENSSL_malloc(min_len);
    201 	if (!*pout)
    202 		return 0;
    203 	if (ssleay_rand_bytes(*pout, min_len, 0, 0) <= 0)
    204 		{
    205 		OPENSSL_free(*pout);
    206 		*pout = NULL;
    207 		return 0;
    208 		}
    209         return min_len;
    210         }
    211 
    212 static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen)
    213 	{
    214 	if (out)
    215 		{
    216 		OPENSSL_cleanse(out, olen);
    217 		OPENSSL_free(out);
    218 		}
    219 	}
    220 
    221 /* Set "additional input" when generating random data. This uses the
    222  * current PID, a time value and a counter.
    223  */
    224 
    225 static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout)
    226     	{
    227 	/* Use of static variables is OK as this happens under a lock */
    228 	static unsigned char buf[16];
    229 	static unsigned long counter;
    230 	FIPS_get_timevec(buf, &counter);
    231 	*pout = buf;
    232 	return sizeof(buf);
    233 	}
    234 
    235 /* RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is
    236  * correctly seeded by RAND_poll().
    237  */
    238 
    239 static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen,
    240 				double entropy)
    241 	{
    242 	RAND_SSLeay()->add(in, inlen, entropy);
    243 	return 1;
    244 	}
    245 
    246 static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen)
    247 	{
    248 	RAND_SSLeay()->seed(in, inlen);
    249 	return 1;
    250 	}
    251 
    252 #ifndef OPENSSL_DRBG_DEFAULT_TYPE
    253 #define OPENSSL_DRBG_DEFAULT_TYPE	NID_aes_256_ctr
    254 #endif
    255 #ifndef OPENSSL_DRBG_DEFAULT_FLAGS
    256 #define OPENSSL_DRBG_DEFAULT_FLAGS	DRBG_FLAG_CTR_USE_DF
    257 #endif
    258 
    259 static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE;
    260 static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS;
    261 
    262 void RAND_set_fips_drbg_type(int type, int flags)
    263 	{
    264 	fips_drbg_type = type;
    265 	fips_drbg_flags = flags;
    266 	}
    267 
    268 int RAND_init_fips(void)
    269 	{
    270 	DRBG_CTX *dctx;
    271 	size_t plen;
    272 	unsigned char pers[32], *p;
    273 #ifndef OPENSSL_ALLOW_DUAL_EC_DRBG
    274 	if (fips_drbg_type >> 16)
    275 		{
    276 		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_DUAL_EC_DRBG_DISABLED);
    277 		return 0;
    278 		}
    279 #endif
    280 
    281 	dctx = FIPS_get_default_drbg();
    282         if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0)
    283 		{
    284 		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG);
    285 		return 0;
    286 		}
    287 
    288         FIPS_drbg_set_callbacks(dctx,
    289 				drbg_get_entropy, drbg_free_entropy, 20,
    290 				drbg_get_entropy, drbg_free_entropy);
    291 	FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0,
    292 					drbg_rand_seed, drbg_rand_add);
    293 	/* Personalisation string: a string followed by date time vector */
    294 	strcpy((char *)pers, "OpenSSL DRBG2.0");
    295 	plen = drbg_get_adin(dctx, &p);
    296 	memcpy(pers + 16, p, plen);
    297 
    298         if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0)
    299 		{
    300 		RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG);
    301 		return 0;
    302 		}
    303         FIPS_rand_set_method(FIPS_drbg_method());
    304 	return 1;
    305 	}
    306 
    307 #endif
    308