1/* crypto/bn/bn_blind.c */ 2/* ==================================================================== 3 * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in 14 * the documentation and/or other materials provided with the 15 * distribution. 16 * 17 * 3. All advertising materials mentioning features or use of this 18 * software must display the following acknowledgment: 19 * "This product includes software developed by the OpenSSL Project 20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 21 * 22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 23 * endorse or promote products derived from this software without 24 * prior written permission. For written permission, please contact 25 * openssl-core@openssl.org. 26 * 27 * 5. Products derived from this software may not be called "OpenSSL" 28 * nor may "OpenSSL" appear in their names without prior written 29 * permission of the OpenSSL Project. 30 * 31 * 6. Redistributions of any form whatsoever must retain the following 32 * acknowledgment: 33 * "This product includes software developed by the OpenSSL Project 34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 35 * 36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 47 * OF THE POSSIBILITY OF SUCH DAMAGE. 48 * ==================================================================== 49 * 50 * This product includes cryptographic software written by Eric Young 51 * (eay@cryptsoft.com). This product includes software written by Tim 52 * Hudson (tjh@cryptsoft.com). 53 * 54 */ 55/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 56 * All rights reserved. 57 * 58 * This package is an SSL implementation written 59 * by Eric Young (eay@cryptsoft.com). 60 * The implementation was written so as to conform with Netscapes SSL. 61 * 62 * This library is free for commercial and non-commercial use as long as 63 * the following conditions are aheared to. The following conditions 64 * apply to all code found in this distribution, be it the RC4, RSA, 65 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 66 * included with this distribution is covered by the same copyright terms 67 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 68 * 69 * Copyright remains Eric Young's, and as such any Copyright notices in 70 * the code are not to be removed. 71 * If this package is used in a product, Eric Young should be given attribution 72 * as the author of the parts of the library used. 73 * This can be in the form of a textual message at program startup or 74 * in documentation (online or textual) provided with the package. 75 * 76 * Redistribution and use in source and binary forms, with or without 77 * modification, are permitted provided that the following conditions 78 * are met: 79 * 1. Redistributions of source code must retain the copyright 80 * notice, this list of conditions and the following disclaimer. 81 * 2. Redistributions in binary form must reproduce the above copyright 82 * notice, this list of conditions and the following disclaimer in the 83 * documentation and/or other materials provided with the distribution. 84 * 3. All advertising materials mentioning features or use of this software 85 * must display the following acknowledgement: 86 * "This product includes cryptographic software written by 87 * Eric Young (eay@cryptsoft.com)" 88 * The word 'cryptographic' can be left out if the rouines from the library 89 * being used are not cryptographic related :-). 90 * 4. If you include any Windows specific code (or a derivative thereof) from 91 * the apps directory (application code) you must include an acknowledgement: 92 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 93 * 94 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 95 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 96 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 97 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 98 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 99 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 100 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 101 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 102 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 103 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 104 * SUCH DAMAGE. 105 * 106 * The licence and distribution terms for any publically available version or 107 * derivative of this code cannot be changed. i.e. this code cannot simply be 108 * copied and put under another distribution licence 109 * [including the GNU Public Licence.] 110 */ 111 112#include <stdio.h> 113#include "cryptlib.h" 114#include "bn_lcl.h" 115 116#define BN_BLINDING_COUNTER 32 117 118struct bn_blinding_st 119 { 120 BIGNUM *A; 121 BIGNUM *Ai; 122 BIGNUM *e; 123 BIGNUM *mod; /* just a reference */ 124#ifndef OPENSSL_NO_DEPRECATED 125 unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b; 126 * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */ 127#endif 128 CRYPTO_THREADID tid; 129 unsigned int counter; 130 unsigned long flags; 131 BN_MONT_CTX *m_ctx; 132 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, 133 const BIGNUM *m, BN_CTX *ctx, 134 BN_MONT_CTX *m_ctx); 135 }; 136 137BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod) 138 { 139 BN_BLINDING *ret=NULL; 140 141 bn_check_top(mod); 142 143 if ((ret=(BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL) 144 { 145 BNerr(BN_F_BN_BLINDING_NEW,ERR_R_MALLOC_FAILURE); 146 return(NULL); 147 } 148 memset(ret,0,sizeof(BN_BLINDING)); 149 if (A != NULL) 150 { 151 if ((ret->A = BN_dup(A)) == NULL) goto err; 152 } 153 if (Ai != NULL) 154 { 155 if ((ret->Ai = BN_dup(Ai)) == NULL) goto err; 156 } 157 158 /* save a copy of mod in the BN_BLINDING structure */ 159 if ((ret->mod = BN_dup(mod)) == NULL) goto err; 160 if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0) 161 BN_set_flags(ret->mod, BN_FLG_CONSTTIME); 162 163 ret->counter = BN_BLINDING_COUNTER; 164 CRYPTO_THREADID_current(&ret->tid); 165 return(ret); 166err: 167 if (ret != NULL) BN_BLINDING_free(ret); 168 return(NULL); 169 } 170 171void BN_BLINDING_free(BN_BLINDING *r) 172 { 173 if(r == NULL) 174 return; 175 176 if (r->A != NULL) BN_free(r->A ); 177 if (r->Ai != NULL) BN_free(r->Ai); 178 if (r->e != NULL) BN_free(r->e ); 179 if (r->mod != NULL) BN_free(r->mod); 180 OPENSSL_free(r); 181 } 182 183int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx) 184 { 185 int ret=0; 186 187 if ((b->A == NULL) || (b->Ai == NULL)) 188 { 189 BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED); 190 goto err; 191 } 192 193 if (--(b->counter) == 0 && b->e != NULL && 194 !(b->flags & BN_BLINDING_NO_RECREATE)) 195 { 196 /* re-create blinding parameters */ 197 if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL)) 198 goto err; 199 } 200 else if (!(b->flags & BN_BLINDING_NO_UPDATE)) 201 { 202 if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err; 203 if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err; 204 } 205 206 ret=1; 207err: 208 if (b->counter == 0) 209 b->counter = BN_BLINDING_COUNTER; 210 return(ret); 211 } 212 213int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx) 214 { 215 return BN_BLINDING_convert_ex(n, NULL, b, ctx); 216 } 217 218int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx) 219 { 220 int ret = 1; 221 222 bn_check_top(n); 223 224 if ((b->A == NULL) || (b->Ai == NULL)) 225 { 226 BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED); 227 return(0); 228 } 229 230 if (r != NULL) 231 { 232 if (!BN_copy(r, b->Ai)) ret=0; 233 } 234 235 if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0; 236 237 return ret; 238 } 239 240int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx) 241 { 242 return BN_BLINDING_invert_ex(n, NULL, b, ctx); 243 } 244 245int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx) 246 { 247 int ret; 248 249 bn_check_top(n); 250 if ((b->A == NULL) || (b->Ai == NULL)) 251 { 252 BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED); 253 return(0); 254 } 255 256 if (r != NULL) 257 ret = BN_mod_mul(n, n, r, b->mod, ctx); 258 else 259 ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx); 260 261 if (ret >= 0) 262 { 263 if (!BN_BLINDING_update(b,ctx)) 264 return(0); 265 } 266 bn_check_top(n); 267 return(ret); 268 } 269 270#ifndef OPENSSL_NO_DEPRECATED 271unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b) 272 { 273 return b->thread_id; 274 } 275 276void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n) 277 { 278 b->thread_id = n; 279 } 280#endif 281 282CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *b) 283 { 284 return &b->tid; 285 } 286 287unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b) 288 { 289 return b->flags; 290 } 291 292void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags) 293 { 294 b->flags = flags; 295 } 296 297BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b, 298 const BIGNUM *e, BIGNUM *m, BN_CTX *ctx, 299 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, 300 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx), 301 BN_MONT_CTX *m_ctx) 302{ 303 int retry_counter = 32; 304 BN_BLINDING *ret = NULL; 305 306 if (b == NULL) 307 ret = BN_BLINDING_new(NULL, NULL, m); 308 else 309 ret = b; 310 311 if (ret == NULL) 312 goto err; 313 314 if (ret->A == NULL && (ret->A = BN_new()) == NULL) 315 goto err; 316 if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL) 317 goto err; 318 319 if (e != NULL) 320 { 321 if (ret->e != NULL) 322 BN_free(ret->e); 323 ret->e = BN_dup(e); 324 } 325 if (ret->e == NULL) 326 goto err; 327 328 if (bn_mod_exp != NULL) 329 ret->bn_mod_exp = bn_mod_exp; 330 if (m_ctx != NULL) 331 ret->m_ctx = m_ctx; 332 333 do { 334 if (!BN_rand_range(ret->A, ret->mod)) goto err; 335 if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL) 336 { 337 /* this should almost never happen for good RSA keys */ 338 unsigned long error = ERR_peek_last_error(); 339 if (ERR_GET_REASON(error) == BN_R_NO_INVERSE) 340 { 341 if (retry_counter-- == 0) 342 { 343 BNerr(BN_F_BN_BLINDING_CREATE_PARAM, 344 BN_R_TOO_MANY_ITERATIONS); 345 goto err; 346 } 347 ERR_clear_error(); 348 } 349 else 350 goto err; 351 } 352 else 353 break; 354 } while (1); 355 356 if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL) 357 { 358 if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx)) 359 goto err; 360 } 361 else 362 { 363 if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx)) 364 goto err; 365 } 366 367 return ret; 368err: 369 if (b == NULL && ret != NULL) 370 { 371 BN_BLINDING_free(ret); 372 ret = NULL; 373 } 374 375 return ret; 376} 377