rand_lib.c revision 296341
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 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 */ 76static ENGINE *funct_ref = NULL; 77#endif 78static const RAND_METHOD *default_RAND_meth = NULL; 79 80int RAND_set_rand_method(const RAND_METHOD *meth) 81{ 82#ifndef OPENSSL_NO_ENGINE 83 if (funct_ref) { 84 ENGINE_finish(funct_ref); 85 funct_ref = NULL; 86 } 87#endif 88 default_RAND_meth = meth; 89 return 1; 90} 91 92const RAND_METHOD *RAND_get_rand_method(void) 93{ 94 if (!default_RAND_meth) { 95#ifndef OPENSSL_NO_ENGINE 96 ENGINE *e = ENGINE_get_default_RAND(); 97 if (e) { 98 default_RAND_meth = ENGINE_get_RAND(e); 99 if (!default_RAND_meth) { 100 ENGINE_finish(e); 101 e = NULL; 102 } 103 } 104 if (e) 105 funct_ref = e; 106 else 107#endif 108 default_RAND_meth = RAND_SSLeay(); 109 } 110 return default_RAND_meth; 111} 112 113#ifndef OPENSSL_NO_ENGINE 114int RAND_set_rand_engine(ENGINE *engine) 115{ 116 const RAND_METHOD *tmp_meth = NULL; 117 if (engine) { 118 if (!ENGINE_init(engine)) 119 return 0; 120 tmp_meth = ENGINE_get_RAND(engine); 121 if (!tmp_meth) { 122 ENGINE_finish(engine); 123 return 0; 124 } 125 } 126 /* This function releases any prior ENGINE so call it first */ 127 RAND_set_rand_method(tmp_meth); 128 funct_ref = engine; 129 return 1; 130} 131#endif 132 133void RAND_cleanup(void) 134{ 135 const RAND_METHOD *meth = RAND_get_rand_method(); 136 if (meth && meth->cleanup) 137 meth->cleanup(); 138 RAND_set_rand_method(NULL); 139} 140 141void RAND_seed(const void *buf, int num) 142{ 143 const RAND_METHOD *meth = RAND_get_rand_method(); 144 if (meth && meth->seed) 145 meth->seed(buf, num); 146} 147 148void RAND_add(const void *buf, int num, double entropy) 149{ 150 const RAND_METHOD *meth = RAND_get_rand_method(); 151 if (meth && meth->add) 152 meth->add(buf, num, entropy); 153} 154 155int RAND_bytes(unsigned char *buf, int num) 156{ 157 const RAND_METHOD *meth = RAND_get_rand_method(); 158 if (meth && meth->bytes) 159 return meth->bytes(buf, num); 160 return (-1); 161} 162 163int RAND_pseudo_bytes(unsigned char *buf, int num) 164{ 165 const RAND_METHOD *meth = RAND_get_rand_method(); 166 if (meth && meth->pseudorand) 167 return meth->pseudorand(buf, num); 168 return (-1); 169} 170 171int RAND_status(void) 172{ 173 const RAND_METHOD *meth = RAND_get_rand_method(); 174 if (meth && meth->status) 175 return meth->status(); 176 return 0; 177} 178 179#ifdef OPENSSL_FIPS 180 181/* 182 * FIPS DRBG initialisation code. This sets up the DRBG for use by the rest 183 * of OpenSSL. 184 */ 185 186/* 187 * Entropy gatherer: use standard OpenSSL PRNG to seed (this will gather 188 * entropy internally through RAND_poll(). 189 */ 190 191static size_t drbg_get_entropy(DRBG_CTX *ctx, unsigned char **pout, 192 int entropy, size_t min_len, size_t max_len) 193{ 194 /* Round up request to multiple of block size */ 195 min_len = ((min_len + 19) / 20) * 20; 196 *pout = OPENSSL_malloc(min_len); 197 if (!*pout) 198 return 0; 199 if (ssleay_rand_bytes(*pout, min_len, 0, 0) <= 0) { 200 OPENSSL_free(*pout); 201 *pout = NULL; 202 return 0; 203 } 204 return min_len; 205} 206 207static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen) 208{ 209 if (out) { 210 OPENSSL_cleanse(out, olen); 211 OPENSSL_free(out); 212 } 213} 214 215/* 216 * Set "additional input" when generating random data. This uses the current 217 * PID, a time value and a counter. 218 */ 219 220static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout) 221{ 222 /* Use of static variables is OK as this happens under a lock */ 223 static unsigned char buf[16]; 224 static unsigned long counter; 225 FIPS_get_timevec(buf, &counter); 226 *pout = buf; 227 return sizeof(buf); 228} 229 230/* 231 * RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is 232 * correctly seeded by RAND_poll(). 233 */ 234 235static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen, 236 double entropy) 237{ 238 RAND_SSLeay()->add(in, inlen, entropy); 239 return 1; 240} 241 242static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen) 243{ 244 RAND_SSLeay()->seed(in, inlen); 245 return 1; 246} 247 248# ifndef OPENSSL_DRBG_DEFAULT_TYPE 249# define OPENSSL_DRBG_DEFAULT_TYPE NID_aes_256_ctr 250# endif 251# ifndef OPENSSL_DRBG_DEFAULT_FLAGS 252# define OPENSSL_DRBG_DEFAULT_FLAGS DRBG_FLAG_CTR_USE_DF 253# endif 254 255static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE; 256static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS; 257 258void RAND_set_fips_drbg_type(int type, int flags) 259{ 260 fips_drbg_type = type; 261 fips_drbg_flags = flags; 262} 263 264int RAND_init_fips(void) 265{ 266 DRBG_CTX *dctx; 267 size_t plen; 268 unsigned char pers[32], *p; 269# ifndef OPENSSL_ALLOW_DUAL_EC_DRBG 270 if (fips_drbg_type >> 16) { 271 RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_DUAL_EC_DRBG_DISABLED); 272 return 0; 273 } 274# endif 275 276 dctx = FIPS_get_default_drbg(); 277 if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0) { 278 RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG); 279 return 0; 280 } 281 282 FIPS_drbg_set_callbacks(dctx, 283 drbg_get_entropy, drbg_free_entropy, 20, 284 drbg_get_entropy, drbg_free_entropy); 285 FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0, 286 drbg_rand_seed, drbg_rand_add); 287 /* Personalisation string: a string followed by date time vector */ 288 strcpy((char *)pers, "OpenSSL DRBG2.0"); 289 plen = drbg_get_adin(dctx, &p); 290 memcpy(pers + 16, p, plen); 291 292 if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0) { 293 RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG); 294 return 0; 295 } 296 FIPS_rand_set_method(FIPS_drbg_method()); 297 return 1; 298} 299 300#endif 301