bn_blind.c revision 160814
1/* crypto/bn/bn_blind.c */ 2/* ==================================================================== 3 * Copyright (c) 1998-2005 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 unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b; 125 * used only by crypto/rsa/rsa_eay.c, rsa_lib.c */ 126 unsigned int counter; 127 unsigned long flags; 128 BN_MONT_CTX *m_ctx; 129 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, 130 const BIGNUM *m, BN_CTX *ctx, 131 BN_MONT_CTX *m_ctx); 132 }; 133 134BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod) 135 { 136 BN_BLINDING *ret=NULL; 137 138 bn_check_top(mod); 139 140 if ((ret=(BN_BLINDING *)OPENSSL_malloc(sizeof(BN_BLINDING))) == NULL) 141 { 142 BNerr(BN_F_BN_BLINDING_NEW,ERR_R_MALLOC_FAILURE); 143 return(NULL); 144 } 145 memset(ret,0,sizeof(BN_BLINDING)); 146 if (A != NULL) 147 { 148 if ((ret->A = BN_dup(A)) == NULL) goto err; 149 } 150 if (Ai != NULL) 151 { 152 if ((ret->Ai = BN_dup(Ai)) == NULL) goto err; 153 } 154 ret->mod = mod; 155 ret->counter = BN_BLINDING_COUNTER; 156 return(ret); 157err: 158 if (ret != NULL) BN_BLINDING_free(ret); 159 return(NULL); 160 } 161 162void BN_BLINDING_free(BN_BLINDING *r) 163 { 164 if(r == NULL) 165 return; 166 167 if (r->A != NULL) BN_free(r->A ); 168 if (r->Ai != NULL) BN_free(r->Ai); 169 if (r->e != NULL) BN_free(r->e ); 170 OPENSSL_free(r); 171 } 172 173int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx) 174 { 175 int ret=0; 176 177 if ((b->A == NULL) || (b->Ai == NULL)) 178 { 179 BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED); 180 goto err; 181 } 182 183 if (--(b->counter) == 0 && b->e != NULL && 184 !(b->flags & BN_BLINDING_NO_RECREATE)) 185 { 186 /* re-create blinding parameters */ 187 if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL)) 188 goto err; 189 } 190 else if (!(b->flags & BN_BLINDING_NO_UPDATE)) 191 { 192 if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err; 193 if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err; 194 } 195 196 ret=1; 197err: 198 if (b->counter == 0) 199 b->counter = BN_BLINDING_COUNTER; 200 return(ret); 201 } 202 203int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx) 204 { 205 return BN_BLINDING_convert_ex(n, NULL, b, ctx); 206 } 207 208int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx) 209 { 210 int ret = 1; 211 212 bn_check_top(n); 213 214 if ((b->A == NULL) || (b->Ai == NULL)) 215 { 216 BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED); 217 return(0); 218 } 219 220 if (r != NULL) 221 { 222 if (!BN_copy(r, b->Ai)) ret=0; 223 } 224 225 if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0; 226 227 return ret; 228 } 229 230int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx) 231 { 232 return BN_BLINDING_invert_ex(n, NULL, b, ctx); 233 } 234 235int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx) 236 { 237 int ret; 238 239 bn_check_top(n); 240 if ((b->A == NULL) || (b->Ai == NULL)) 241 { 242 BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED); 243 return(0); 244 } 245 246 if (r != NULL) 247 ret = BN_mod_mul(n, n, r, b->mod, ctx); 248 else 249 ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx); 250 251 if (ret >= 0) 252 { 253 if (!BN_BLINDING_update(b,ctx)) 254 return(0); 255 } 256 bn_check_top(n); 257 return(ret); 258 } 259 260unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b) 261 { 262 return b->thread_id; 263 } 264 265void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n) 266 { 267 b->thread_id = n; 268 } 269 270unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b) 271 { 272 return b->flags; 273 } 274 275void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags) 276 { 277 b->flags = flags; 278 } 279 280BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b, 281 const BIGNUM *e, BIGNUM *m, BN_CTX *ctx, 282 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, 283 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx), 284 BN_MONT_CTX *m_ctx) 285{ 286 int retry_counter = 32; 287 BN_BLINDING *ret = NULL; 288 289 if (b == NULL) 290 ret = BN_BLINDING_new(NULL, NULL, m); 291 else 292 ret = b; 293 294 if (ret == NULL) 295 goto err; 296 297 if (ret->A == NULL && (ret->A = BN_new()) == NULL) 298 goto err; 299 if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL) 300 goto err; 301 302 if (e != NULL) 303 { 304 if (ret->e != NULL) 305 BN_free(ret->e); 306 ret->e = BN_dup(e); 307 } 308 if (ret->e == NULL) 309 goto err; 310 311 if (bn_mod_exp != NULL) 312 ret->bn_mod_exp = bn_mod_exp; 313 if (m_ctx != NULL) 314 ret->m_ctx = m_ctx; 315 316 do { 317 if (!BN_rand_range(ret->A, ret->mod)) goto err; 318 if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL) 319 { 320 /* this should almost never happen for good RSA keys */ 321 unsigned long error = ERR_peek_last_error(); 322 if (ERR_GET_REASON(error) == BN_R_NO_INVERSE) 323 { 324 if (retry_counter-- == 0) 325 { 326 BNerr(BN_F_BN_BLINDING_CREATE_PARAM, 327 BN_R_TOO_MANY_ITERATIONS); 328 goto err; 329 } 330 ERR_clear_error(); 331 } 332 else 333 goto err; 334 } 335 else 336 break; 337 } while (1); 338 339 if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL) 340 { 341 if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx)) 342 goto err; 343 } 344 else 345 { 346 if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx)) 347 goto err; 348 } 349 350 return ret; 351err: 352 if (b == NULL && ret != NULL) 353 { 354 BN_BLINDING_free(ret); 355 ret = NULL; 356 } 357 358 return ret; 359} 360