rand_lib.c revision 340704
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; 199 200 /* Enforces a reseed of the SSLEAY PRNG before generating random bytes */ 201 if (ssleay_rand_bytes_from_system(*pout, min_len) <= 0) { 202 OPENSSL_free(*pout); 203 *pout = NULL; 204 return 0; 205 } 206 return min_len; 207} 208 209static size_t drbg_get_nonce(DRBG_CTX *ctx, unsigned char **pout, 210 int entropy, size_t min_len, size_t max_len) 211{ 212 /* Round up request to multiple of block size */ 213 min_len = ((min_len + 19) / 20) * 20; 214 *pout = OPENSSL_malloc(min_len); 215 if (!*pout) 216 return 0; 217 if (ssleay_rand_bytes(*pout, min_len, 0, 0) <= 0) { 218 OPENSSL_free(*pout); 219 *pout = NULL; 220 return 0; 221 } 222 return min_len; 223} 224 225static void drbg_free_entropy(DRBG_CTX *ctx, unsigned char *out, size_t olen) 226{ 227 if (out) { 228 OPENSSL_cleanse(out, olen); 229 OPENSSL_free(out); 230 } 231} 232 233/* 234 * Set "additional input" when generating random data. This uses the current 235 * PID, a time value and a counter. 236 */ 237 238static size_t drbg_get_adin(DRBG_CTX *ctx, unsigned char **pout) 239{ 240 /* Use of static variables is OK as this happens under a lock */ 241 static unsigned char buf[16]; 242 static unsigned long counter; 243 FIPS_get_timevec(buf, &counter); 244 *pout = buf; 245 return sizeof(buf); 246} 247 248/* 249 * RAND_add() and RAND_seed() pass through to OpenSSL PRNG so it is 250 * correctly seeded by RAND_poll(). 251 */ 252 253static int drbg_rand_add(DRBG_CTX *ctx, const void *in, int inlen, 254 double entropy) 255{ 256 RAND_SSLeay()->add(in, inlen, entropy); 257 return 1; 258} 259 260static int drbg_rand_seed(DRBG_CTX *ctx, const void *in, int inlen) 261{ 262 RAND_SSLeay()->seed(in, inlen); 263 return 1; 264} 265 266# ifndef OPENSSL_DRBG_DEFAULT_TYPE 267# define OPENSSL_DRBG_DEFAULT_TYPE NID_aes_256_ctr 268# endif 269# ifndef OPENSSL_DRBG_DEFAULT_FLAGS 270# define OPENSSL_DRBG_DEFAULT_FLAGS DRBG_FLAG_CTR_USE_DF 271# endif 272 273static int fips_drbg_type = OPENSSL_DRBG_DEFAULT_TYPE; 274static int fips_drbg_flags = OPENSSL_DRBG_DEFAULT_FLAGS; 275 276void RAND_set_fips_drbg_type(int type, int flags) 277{ 278 fips_drbg_type = type; 279 fips_drbg_flags = flags; 280} 281 282int RAND_init_fips(void) 283{ 284 DRBG_CTX *dctx; 285 size_t plen; 286 unsigned char pers[32], *p; 287# ifndef OPENSSL_ALLOW_DUAL_EC_DRBG 288 if (fips_drbg_type >> 16) { 289 RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_DUAL_EC_DRBG_DISABLED); 290 return 0; 291 } 292# endif 293 294 dctx = FIPS_get_default_drbg(); 295 if (FIPS_drbg_init(dctx, fips_drbg_type, fips_drbg_flags) <= 0) { 296 RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INITIALISING_DRBG); 297 return 0; 298 } 299 300 FIPS_drbg_set_callbacks(dctx, 301 drbg_get_entropy, drbg_free_entropy, 20, 302 drbg_get_nonce, drbg_free_entropy); 303 FIPS_drbg_set_rand_callbacks(dctx, drbg_get_adin, 0, 304 drbg_rand_seed, drbg_rand_add); 305 /* Personalisation string: a string followed by date time vector */ 306 strcpy((char *)pers, "OpenSSL DRBG2.0"); 307 plen = drbg_get_adin(dctx, &p); 308 memcpy(pers + 16, p, plen); 309 310 if (FIPS_drbg_instantiate(dctx, pers, sizeof(pers)) <= 0) { 311 RANDerr(RAND_F_RAND_INIT_FIPS, RAND_R_ERROR_INSTANTIATING_DRBG); 312 return 0; 313 } 314 FIPS_rand_set_method(FIPS_drbg_method()); 315 return 1; 316} 317 318#endif 319