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 32 117 118 struct 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 }; 133 134 BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, /* const */ 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 } 154 155 /* save a copy of mod in the BN_BLINDING structure */ 156 if ((ret->mod = BN_dup(mod)) == NULL) goto err; 157 if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0) 158 BN_set_flags(ret->mod, BN_FLG_CONSTTIME); 159 160 ret->counter = BN_BLINDING_COUNTER; 161 return(ret); 162 err: 163 if (ret != NULL) BN_BLINDING_free(ret); 164 return(NULL); 165 } 166 167 void BN_BLINDING_free(BN_BLINDING *r) 168 { 169 if(r == NULL) 170 return; 171 172 if (r->A != NULL) BN_free(r->A ); 173 if (r->Ai != NULL) BN_free(r->Ai); 174 if (r->e != NULL) BN_free(r->e ); 175 if (r->mod != NULL) BN_free(r->mod); 176 OPENSSL_free(r); 177 } 178 179 int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx) 180 { 181 int ret=0; 182 183 if ((b->A == NULL) || (b->Ai == NULL)) 184 { 185 BNerr(BN_F_BN_BLINDING_UPDATE,BN_R_NOT_INITIALIZED); 186 goto err; 187 } 188 189 if (--(b->counter) == 0 && b->e != NULL && 190 !(b->flags & BN_BLINDING_NO_RECREATE)) 191 { 192 /* re-create blinding parameters */ 193 if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL)) 194 goto err; 195 } 196 else if (!(b->flags & BN_BLINDING_NO_UPDATE)) 197 { 198 if (!BN_mod_mul(b->A,b->A,b->A,b->mod,ctx)) goto err; 199 if (!BN_mod_mul(b->Ai,b->Ai,b->Ai,b->mod,ctx)) goto err; 200 } 201 202 ret=1; 203 err: 204 if (b->counter == 0) 205 b->counter = BN_BLINDING_COUNTER; 206 return(ret); 207 } 208 209 int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx) 210 { 211 return BN_BLINDING_convert_ex(n, NULL, b, ctx); 212 } 213 214 int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx) 215 { 216 int ret = 1; 217 218 bn_check_top(n); 219 220 if ((b->A == NULL) || (b->Ai == NULL)) 221 { 222 BNerr(BN_F_BN_BLINDING_CONVERT_EX,BN_R_NOT_INITIALIZED); 223 return(0); 224 } 225 226 if (r != NULL) 227 { 228 if (!BN_copy(r, b->Ai)) ret=0; 229 } 230 231 if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0; 232 233 return ret; 234 } 235 236 int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx) 237 { 238 return BN_BLINDING_invert_ex(n, NULL, b, ctx); 239 } 240 241 int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx) 242 { 243 int ret; 244 245 bn_check_top(n); 246 if ((b->A == NULL) || (b->Ai == NULL)) 247 { 248 BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED); 249 return(0); 250 } 251 252 if (r != NULL) 253 ret = BN_mod_mul(n, n, r, b->mod, ctx); 254 else 255 ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx); 256 257 if (ret >= 0) 258 { 259 if (!BN_BLINDING_update(b,ctx)) 260 return(0); 261 } 262 bn_check_top(n); 263 return(ret); 264 } 265 266 unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *b) 267 { 268 return b->thread_id; 269 } 270 271 void BN_BLINDING_set_thread_id(BN_BLINDING *b, unsigned long n) 272 { 273 b->thread_id = n; 274 } 275 276 unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b) 277 { 278 return b->flags; 279 } 280 281 void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags) 282 { 283 b->flags = flags; 284 } 285 286 BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b, 287 const BIGNUM *e, /* const */ BIGNUM *m, BN_CTX *ctx, 288 int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, 289 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx), 290 BN_MONT_CTX *m_ctx) 291 { 292 int retry_counter = 32; 293 BN_BLINDING *ret = NULL; 294 295 if (b == NULL) 296 ret = BN_BLINDING_new(NULL, NULL, m); 297 else 298 ret = b; 299 300 if (ret == NULL) 301 goto err; 302 303 if (ret->A == NULL && (ret->A = BN_new()) == NULL) 304 goto err; 305 if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL) 306 goto err; 307 308 if (e != NULL) 309 { 310 if (ret->e != NULL) 311 BN_free(ret->e); 312 ret->e = BN_dup(e); 313 } 314 if (ret->e == NULL) 315 goto err; 316 317 if (bn_mod_exp != NULL) 318 ret->bn_mod_exp = bn_mod_exp; 319 if (m_ctx != NULL) 320 ret->m_ctx = m_ctx; 321 322 do { 323 if (!BN_rand_range(ret->A, ret->mod)) goto err; 324 if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL) 325 { 326 /* this should almost never happen for good RSA keys */ 327 unsigned long error = ERR_peek_last_error(); 328 if (ERR_GET_REASON(error) == BN_R_NO_INVERSE) 329 { 330 if (retry_counter-- == 0) 331 { 332 BNerr(BN_F_BN_BLINDING_CREATE_PARAM, 333 BN_R_TOO_MANY_ITERATIONS); 334 goto err; 335 } 336 ERR_clear_error(); 337 } 338 else 339 goto err; 340 } 341 else 342 break; 343 } while (1); 344 345 if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL) 346 { 347 if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx)) 348 goto err; 349 } 350 else 351 { 352 if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx)) 353 goto err; 354 } 355 356 return ret; 357 err: 358 if (b == NULL && ret != NULL) 359 { 360 BN_BLINDING_free(ret); 361 ret = NULL; 362 } 363 364 return ret; 365 } 366