Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame^] | 1 | /* crypto/rsa/rsa_eay.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 | * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved. |
| 60 | * |
| 61 | * Redistribution and use in source and binary forms, with or without |
| 62 | * modification, are permitted provided that the following conditions |
| 63 | * are met: |
| 64 | * |
| 65 | * 1. Redistributions of source code must retain the above copyright |
| 66 | * notice, this list of conditions and the following disclaimer. |
| 67 | * |
| 68 | * 2. Redistributions in binary form must reproduce the above copyright |
| 69 | * notice, this list of conditions and the following disclaimer in |
| 70 | * the documentation and/or other materials provided with the |
| 71 | * distribution. |
| 72 | * |
| 73 | * 3. All advertising materials mentioning features or use of this |
| 74 | * software must display the following acknowledgment: |
| 75 | * "This product includes software developed by the OpenSSL Project |
| 76 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" |
| 77 | * |
| 78 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| 79 | * endorse or promote products derived from this software without |
| 80 | * prior written permission. For written permission, please contact |
| 81 | * openssl-core@openssl.org. |
| 82 | * |
| 83 | * 5. Products derived from this software may not be called "OpenSSL" |
| 84 | * nor may "OpenSSL" appear in their names without prior written |
| 85 | * permission of the OpenSSL Project. |
| 86 | * |
| 87 | * 6. Redistributions of any form whatsoever must retain the following |
| 88 | * acknowledgment: |
| 89 | * "This product includes software developed by the OpenSSL Project |
| 90 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" |
| 91 | * |
| 92 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| 93 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 94 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 95 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| 96 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 97 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 98 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 99 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 100 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 101 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 102 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| 103 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
| 104 | * ==================================================================== |
| 105 | * |
| 106 | * This product includes cryptographic software written by Eric Young |
| 107 | * (eay@cryptsoft.com). This product includes software written by Tim |
| 108 | * Hudson (tjh@cryptsoft.com). |
| 109 | * |
| 110 | */ |
| 111 | |
| 112 | #include <stdio.h> |
| 113 | #include "cryptlib.h" |
| 114 | #include <openssl/bn.h> |
| 115 | #include <openssl/rsa.h> |
| 116 | #include <openssl/rand.h> |
| 117 | |
| 118 | #ifndef RSA_NULL |
| 119 | |
| 120 | static int RSA_eay_public_encrypt(int flen, const unsigned char *from, |
| 121 | unsigned char *to, RSA *rsa,int padding); |
| 122 | static int RSA_eay_private_encrypt(int flen, const unsigned char *from, |
| 123 | unsigned char *to, RSA *rsa,int padding); |
| 124 | static int RSA_eay_public_decrypt(int flen, const unsigned char *from, |
| 125 | unsigned char *to, RSA *rsa,int padding); |
| 126 | static int RSA_eay_private_decrypt(int flen, const unsigned char *from, |
| 127 | unsigned char *to, RSA *rsa,int padding); |
| 128 | static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx); |
| 129 | static int RSA_eay_init(RSA *rsa); |
| 130 | static int RSA_eay_finish(RSA *rsa); |
| 131 | static RSA_METHOD rsa_pkcs1_eay_meth={ |
| 132 | "Eric Young's PKCS#1 RSA", |
| 133 | RSA_eay_public_encrypt, |
| 134 | RSA_eay_public_decrypt, /* signature verification */ |
| 135 | RSA_eay_private_encrypt, /* signing */ |
| 136 | RSA_eay_private_decrypt, |
| 137 | RSA_eay_mod_exp, |
| 138 | BN_mod_exp_mont, /* XXX probably we should not use Montgomery if e == 3 */ |
| 139 | RSA_eay_init, |
| 140 | RSA_eay_finish, |
| 141 | 0, /* flags */ |
| 142 | NULL, |
| 143 | 0, /* rsa_sign */ |
| 144 | 0, /* rsa_verify */ |
| 145 | NULL /* rsa_keygen */ |
| 146 | }; |
| 147 | |
| 148 | const RSA_METHOD *RSA_PKCS1_SSLeay(void) |
| 149 | { |
| 150 | return(&rsa_pkcs1_eay_meth); |
| 151 | } |
| 152 | |
| 153 | static int RSA_eay_public_encrypt(int flen, const unsigned char *from, |
| 154 | unsigned char *to, RSA *rsa, int padding) |
| 155 | { |
| 156 | BIGNUM *f,*ret; |
| 157 | int i,j,k,num=0,r= -1; |
| 158 | unsigned char *buf=NULL; |
| 159 | BN_CTX *ctx=NULL; |
| 160 | |
| 161 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) |
| 162 | { |
| 163 | RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE); |
| 164 | return -1; |
| 165 | } |
| 166 | |
| 167 | if (BN_ucmp(rsa->n, rsa->e) <= 0) |
| 168 | { |
| 169 | RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE); |
| 170 | return -1; |
| 171 | } |
| 172 | |
| 173 | /* for large moduli, enforce exponent limit */ |
| 174 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) |
| 175 | { |
| 176 | if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) |
| 177 | { |
| 178 | RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE); |
| 179 | return -1; |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | if ((ctx=BN_CTX_new()) == NULL) goto err; |
| 184 | BN_CTX_start(ctx); |
| 185 | f = BN_CTX_get(ctx); |
| 186 | ret = BN_CTX_get(ctx); |
| 187 | num=BN_num_bytes(rsa->n); |
| 188 | buf = OPENSSL_malloc(num); |
| 189 | if (!f || !ret || !buf) |
| 190 | { |
| 191 | RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE); |
| 192 | goto err; |
| 193 | } |
| 194 | |
| 195 | switch (padding) |
| 196 | { |
| 197 | case RSA_PKCS1_PADDING: |
| 198 | i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen); |
| 199 | break; |
| 200 | #ifndef OPENSSL_NO_SHA |
| 201 | case RSA_PKCS1_OAEP_PADDING: |
| 202 | i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0); |
| 203 | break; |
| 204 | #endif |
| 205 | case RSA_SSLV23_PADDING: |
| 206 | i=RSA_padding_add_SSLv23(buf,num,from,flen); |
| 207 | break; |
| 208 | case RSA_NO_PADDING: |
| 209 | i=RSA_padding_add_none(buf,num,from,flen); |
| 210 | break; |
| 211 | default: |
| 212 | RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE); |
| 213 | goto err; |
| 214 | } |
| 215 | if (i <= 0) goto err; |
| 216 | |
| 217 | if (BN_bin2bn(buf,num,f) == NULL) goto err; |
| 218 | |
| 219 | if (BN_ucmp(f, rsa->n) >= 0) |
| 220 | { |
| 221 | /* usually the padding functions would catch this */ |
| 222 | RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
| 223 | goto err; |
| 224 | } |
| 225 | |
| 226 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) |
| 227 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) |
| 228 | goto err; |
| 229 | |
| 230 | if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx, |
| 231 | rsa->_method_mod_n)) goto err; |
| 232 | |
| 233 | /* put in leading 0 bytes if the number is less than the |
| 234 | * length of the modulus */ |
| 235 | j=BN_num_bytes(ret); |
| 236 | i=BN_bn2bin(ret,&(to[num-j])); |
| 237 | for (k=0; k<(num-i); k++) |
| 238 | to[k]=0; |
| 239 | |
| 240 | r=num; |
| 241 | err: |
| 242 | if (ctx != NULL) |
| 243 | { |
| 244 | BN_CTX_end(ctx); |
| 245 | BN_CTX_free(ctx); |
| 246 | } |
| 247 | if (buf != NULL) |
| 248 | { |
| 249 | OPENSSL_cleanse(buf,num); |
| 250 | OPENSSL_free(buf); |
| 251 | } |
| 252 | return(r); |
| 253 | } |
| 254 | |
| 255 | static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx) |
| 256 | { |
| 257 | BN_BLINDING *ret; |
| 258 | int got_write_lock = 0; |
| 259 | CRYPTO_THREADID cur; |
| 260 | |
| 261 | CRYPTO_r_lock(CRYPTO_LOCK_RSA); |
| 262 | |
| 263 | if (rsa->blinding == NULL) |
| 264 | { |
| 265 | CRYPTO_r_unlock(CRYPTO_LOCK_RSA); |
| 266 | CRYPTO_w_lock(CRYPTO_LOCK_RSA); |
| 267 | got_write_lock = 1; |
| 268 | |
| 269 | if (rsa->blinding == NULL) |
| 270 | rsa->blinding = RSA_setup_blinding(rsa, ctx); |
| 271 | } |
| 272 | |
| 273 | ret = rsa->blinding; |
| 274 | if (ret == NULL) |
| 275 | goto err; |
| 276 | |
| 277 | CRYPTO_THREADID_current(&cur); |
| 278 | if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) |
| 279 | { |
| 280 | /* rsa->blinding is ours! */ |
| 281 | |
| 282 | *local = 1; |
| 283 | } |
| 284 | else |
| 285 | { |
| 286 | /* resort to rsa->mt_blinding instead */ |
| 287 | |
| 288 | *local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert() |
| 289 | * that the BN_BLINDING is shared, meaning that accesses |
| 290 | * require locks, and that the blinding factor must be |
| 291 | * stored outside the BN_BLINDING |
| 292 | */ |
| 293 | |
| 294 | if (rsa->mt_blinding == NULL) |
| 295 | { |
| 296 | if (!got_write_lock) |
| 297 | { |
| 298 | CRYPTO_r_unlock(CRYPTO_LOCK_RSA); |
| 299 | CRYPTO_w_lock(CRYPTO_LOCK_RSA); |
| 300 | got_write_lock = 1; |
| 301 | } |
| 302 | |
| 303 | if (rsa->mt_blinding == NULL) |
| 304 | rsa->mt_blinding = RSA_setup_blinding(rsa, ctx); |
| 305 | } |
| 306 | ret = rsa->mt_blinding; |
| 307 | } |
| 308 | |
| 309 | err: |
| 310 | if (got_write_lock) |
| 311 | CRYPTO_w_unlock(CRYPTO_LOCK_RSA); |
| 312 | else |
| 313 | CRYPTO_r_unlock(CRYPTO_LOCK_RSA); |
| 314 | return ret; |
| 315 | } |
| 316 | |
| 317 | static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, |
| 318 | BN_CTX *ctx) |
| 319 | { |
| 320 | if (unblind == NULL) |
| 321 | /* Local blinding: store the unblinding factor |
| 322 | * in BN_BLINDING. */ |
| 323 | return BN_BLINDING_convert_ex(f, NULL, b, ctx); |
| 324 | else |
| 325 | { |
| 326 | /* Shared blinding: store the unblinding factor |
| 327 | * outside BN_BLINDING. */ |
| 328 | int ret; |
| 329 | CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING); |
| 330 | ret = BN_BLINDING_convert_ex(f, unblind, b, ctx); |
| 331 | CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING); |
| 332 | return ret; |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, |
| 337 | BN_CTX *ctx) |
| 338 | { |
| 339 | /* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex |
| 340 | * will use the unblinding factor stored in BN_BLINDING. |
| 341 | * If BN_BLINDING is shared between threads, unblind must be non-null: |
| 342 | * BN_BLINDING_invert_ex will then use the local unblinding factor, |
| 343 | * and will only read the modulus from BN_BLINDING. |
| 344 | * In both cases it's safe to access the blinding without a lock. |
| 345 | */ |
| 346 | return BN_BLINDING_invert_ex(f, unblind, b, ctx); |
| 347 | } |
| 348 | |
| 349 | /* signing */ |
| 350 | static int RSA_eay_private_encrypt(int flen, const unsigned char *from, |
| 351 | unsigned char *to, RSA *rsa, int padding) |
| 352 | { |
| 353 | BIGNUM *f, *ret, *res; |
| 354 | int i,j,k,num=0,r= -1; |
| 355 | unsigned char *buf=NULL; |
| 356 | BN_CTX *ctx=NULL; |
| 357 | int local_blinding = 0; |
| 358 | /* Used only if the blinding structure is shared. A non-NULL unblind |
| 359 | * instructs rsa_blinding_convert() and rsa_blinding_invert() to store |
| 360 | * the unblinding factor outside the blinding structure. */ |
| 361 | BIGNUM *unblind = NULL; |
| 362 | BN_BLINDING *blinding = NULL; |
| 363 | |
| 364 | if ((ctx=BN_CTX_new()) == NULL) goto err; |
| 365 | BN_CTX_start(ctx); |
| 366 | f = BN_CTX_get(ctx); |
| 367 | ret = BN_CTX_get(ctx); |
| 368 | num = BN_num_bytes(rsa->n); |
| 369 | buf = OPENSSL_malloc(num); |
| 370 | if(!f || !ret || !buf) |
| 371 | { |
| 372 | RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE); |
| 373 | goto err; |
| 374 | } |
| 375 | |
| 376 | switch (padding) |
| 377 | { |
| 378 | case RSA_PKCS1_PADDING: |
| 379 | i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen); |
| 380 | break; |
| 381 | case RSA_X931_PADDING: |
| 382 | i=RSA_padding_add_X931(buf,num,from,flen); |
| 383 | break; |
| 384 | case RSA_NO_PADDING: |
| 385 | i=RSA_padding_add_none(buf,num,from,flen); |
| 386 | break; |
| 387 | case RSA_SSLV23_PADDING: |
| 388 | default: |
| 389 | RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE); |
| 390 | goto err; |
| 391 | } |
| 392 | if (i <= 0) goto err; |
| 393 | |
| 394 | if (BN_bin2bn(buf,num,f) == NULL) goto err; |
| 395 | |
| 396 | if (BN_ucmp(f, rsa->n) >= 0) |
| 397 | { |
| 398 | /* usually the padding functions would catch this */ |
| 399 | RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
| 400 | goto err; |
| 401 | } |
| 402 | |
| 403 | if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) |
| 404 | { |
| 405 | blinding = rsa_get_blinding(rsa, &local_blinding, ctx); |
| 406 | if (blinding == NULL) |
| 407 | { |
| 408 | RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR); |
| 409 | goto err; |
| 410 | } |
| 411 | } |
| 412 | |
| 413 | if (blinding != NULL) |
| 414 | { |
| 415 | if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) |
| 416 | { |
| 417 | RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE); |
| 418 | goto err; |
| 419 | } |
| 420 | if (!rsa_blinding_convert(blinding, f, unblind, ctx)) |
| 421 | goto err; |
| 422 | } |
| 423 | |
| 424 | if ( (rsa->flags & RSA_FLAG_EXT_PKEY) || |
| 425 | ((rsa->p != NULL) && |
| 426 | (rsa->q != NULL) && |
| 427 | (rsa->dmp1 != NULL) && |
| 428 | (rsa->dmq1 != NULL) && |
| 429 | (rsa->iqmp != NULL)) ) |
| 430 | { |
| 431 | if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; |
| 432 | } |
| 433 | else |
| 434 | { |
| 435 | BIGNUM local_d; |
| 436 | BIGNUM *d = NULL; |
| 437 | |
| 438 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 439 | { |
| 440 | BN_init(&local_d); |
| 441 | d = &local_d; |
| 442 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
| 443 | } |
| 444 | else |
| 445 | d= rsa->d; |
| 446 | |
| 447 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) |
| 448 | if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) |
| 449 | goto err; |
| 450 | |
| 451 | if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx, |
| 452 | rsa->_method_mod_n)) goto err; |
| 453 | } |
| 454 | |
| 455 | if (blinding) |
| 456 | if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) |
| 457 | goto err; |
| 458 | |
| 459 | if (padding == RSA_X931_PADDING) |
| 460 | { |
| 461 | BN_sub(f, rsa->n, ret); |
| 462 | if (BN_cmp(ret, f)) |
| 463 | res = f; |
| 464 | else |
| 465 | res = ret; |
| 466 | } |
| 467 | else |
| 468 | res = ret; |
| 469 | |
| 470 | /* put in leading 0 bytes if the number is less than the |
| 471 | * length of the modulus */ |
| 472 | j=BN_num_bytes(res); |
| 473 | i=BN_bn2bin(res,&(to[num-j])); |
| 474 | for (k=0; k<(num-i); k++) |
| 475 | to[k]=0; |
| 476 | |
| 477 | r=num; |
| 478 | err: |
| 479 | if (ctx != NULL) |
| 480 | { |
| 481 | BN_CTX_end(ctx); |
| 482 | BN_CTX_free(ctx); |
| 483 | } |
| 484 | if (buf != NULL) |
| 485 | { |
| 486 | OPENSSL_cleanse(buf,num); |
| 487 | OPENSSL_free(buf); |
| 488 | } |
| 489 | return(r); |
| 490 | } |
| 491 | |
| 492 | static int RSA_eay_private_decrypt(int flen, const unsigned char *from, |
| 493 | unsigned char *to, RSA *rsa, int padding) |
| 494 | { |
| 495 | BIGNUM *f, *ret; |
| 496 | int j,num=0,r= -1; |
| 497 | unsigned char *p; |
| 498 | unsigned char *buf=NULL; |
| 499 | BN_CTX *ctx=NULL; |
| 500 | int local_blinding = 0; |
| 501 | /* Used only if the blinding structure is shared. A non-NULL unblind |
| 502 | * instructs rsa_blinding_convert() and rsa_blinding_invert() to store |
| 503 | * the unblinding factor outside the blinding structure. */ |
| 504 | BIGNUM *unblind = NULL; |
| 505 | BN_BLINDING *blinding = NULL; |
| 506 | |
| 507 | if((ctx = BN_CTX_new()) == NULL) goto err; |
| 508 | BN_CTX_start(ctx); |
| 509 | f = BN_CTX_get(ctx); |
| 510 | ret = BN_CTX_get(ctx); |
| 511 | num = BN_num_bytes(rsa->n); |
| 512 | buf = OPENSSL_malloc(num); |
| 513 | if(!f || !ret || !buf) |
| 514 | { |
| 515 | RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE); |
| 516 | goto err; |
| 517 | } |
| 518 | |
| 519 | /* This check was for equality but PGP does evil things |
| 520 | * and chops off the top '0' bytes */ |
| 521 | if (flen > num) |
| 522 | { |
| 523 | RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); |
| 524 | goto err; |
| 525 | } |
| 526 | |
| 527 | /* make data into a big number */ |
| 528 | if (BN_bin2bn(from,(int)flen,f) == NULL) goto err; |
| 529 | |
| 530 | if (BN_ucmp(f, rsa->n) >= 0) |
| 531 | { |
| 532 | RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
| 533 | goto err; |
| 534 | } |
| 535 | |
| 536 | if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) |
| 537 | { |
| 538 | blinding = rsa_get_blinding(rsa, &local_blinding, ctx); |
| 539 | if (blinding == NULL) |
| 540 | { |
| 541 | RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR); |
| 542 | goto err; |
| 543 | } |
| 544 | } |
| 545 | |
| 546 | if (blinding != NULL) |
| 547 | { |
| 548 | if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) |
| 549 | { |
| 550 | RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE); |
| 551 | goto err; |
| 552 | } |
| 553 | if (!rsa_blinding_convert(blinding, f, unblind, ctx)) |
| 554 | goto err; |
| 555 | } |
| 556 | |
| 557 | /* do the decrypt */ |
| 558 | if ( (rsa->flags & RSA_FLAG_EXT_PKEY) || |
| 559 | ((rsa->p != NULL) && |
| 560 | (rsa->q != NULL) && |
| 561 | (rsa->dmp1 != NULL) && |
| 562 | (rsa->dmq1 != NULL) && |
| 563 | (rsa->iqmp != NULL)) ) |
| 564 | { |
| 565 | if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err; |
| 566 | } |
| 567 | else |
| 568 | { |
| 569 | BIGNUM local_d; |
| 570 | BIGNUM *d = NULL; |
| 571 | |
| 572 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 573 | { |
| 574 | d = &local_d; |
| 575 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
| 576 | } |
| 577 | else |
| 578 | d = rsa->d; |
| 579 | |
| 580 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) |
| 581 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) |
| 582 | goto err; |
| 583 | if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx, |
| 584 | rsa->_method_mod_n)) |
| 585 | goto err; |
| 586 | } |
| 587 | |
| 588 | if (blinding) |
| 589 | if (!rsa_blinding_invert(blinding, ret, unblind, ctx)) |
| 590 | goto err; |
| 591 | |
| 592 | p=buf; |
| 593 | j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */ |
| 594 | |
| 595 | switch (padding) |
| 596 | { |
| 597 | case RSA_PKCS1_PADDING: |
| 598 | r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num); |
| 599 | break; |
| 600 | #ifndef OPENSSL_NO_SHA |
| 601 | case RSA_PKCS1_OAEP_PADDING: |
| 602 | r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0); |
| 603 | break; |
| 604 | #endif |
| 605 | case RSA_SSLV23_PADDING: |
| 606 | r=RSA_padding_check_SSLv23(to,num,buf,j,num); |
| 607 | break; |
| 608 | case RSA_NO_PADDING: |
| 609 | r=RSA_padding_check_none(to,num,buf,j,num); |
| 610 | break; |
| 611 | default: |
| 612 | RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); |
| 613 | goto err; |
| 614 | } |
| 615 | if (r < 0) |
| 616 | RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED); |
| 617 | |
| 618 | err: |
| 619 | if (ctx != NULL) |
| 620 | { |
| 621 | BN_CTX_end(ctx); |
| 622 | BN_CTX_free(ctx); |
| 623 | } |
| 624 | if (buf != NULL) |
| 625 | { |
| 626 | OPENSSL_cleanse(buf,num); |
| 627 | OPENSSL_free(buf); |
| 628 | } |
| 629 | return(r); |
| 630 | } |
| 631 | |
| 632 | /* signature verification */ |
| 633 | static int RSA_eay_public_decrypt(int flen, const unsigned char *from, |
| 634 | unsigned char *to, RSA *rsa, int padding) |
| 635 | { |
| 636 | BIGNUM *f,*ret; |
| 637 | int i,num=0,r= -1; |
| 638 | unsigned char *p; |
| 639 | unsigned char *buf=NULL; |
| 640 | BN_CTX *ctx=NULL; |
| 641 | |
| 642 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) |
| 643 | { |
| 644 | RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE); |
| 645 | return -1; |
| 646 | } |
| 647 | |
| 648 | if (BN_ucmp(rsa->n, rsa->e) <= 0) |
| 649 | { |
| 650 | RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); |
| 651 | return -1; |
| 652 | } |
| 653 | |
| 654 | /* for large moduli, enforce exponent limit */ |
| 655 | if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) |
| 656 | { |
| 657 | if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) |
| 658 | { |
| 659 | RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE); |
| 660 | return -1; |
| 661 | } |
| 662 | } |
| 663 | |
| 664 | if((ctx = BN_CTX_new()) == NULL) goto err; |
| 665 | BN_CTX_start(ctx); |
| 666 | f = BN_CTX_get(ctx); |
| 667 | ret = BN_CTX_get(ctx); |
| 668 | num=BN_num_bytes(rsa->n); |
| 669 | buf = OPENSSL_malloc(num); |
| 670 | if(!f || !ret || !buf) |
| 671 | { |
| 672 | RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE); |
| 673 | goto err; |
| 674 | } |
| 675 | |
| 676 | /* This check was for equality but PGP does evil things |
| 677 | * and chops off the top '0' bytes */ |
| 678 | if (flen > num) |
| 679 | { |
| 680 | RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN); |
| 681 | goto err; |
| 682 | } |
| 683 | |
| 684 | if (BN_bin2bn(from,flen,f) == NULL) goto err; |
| 685 | |
| 686 | if (BN_ucmp(f, rsa->n) >= 0) |
| 687 | { |
| 688 | RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS); |
| 689 | goto err; |
| 690 | } |
| 691 | |
| 692 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) |
| 693 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) |
| 694 | goto err; |
| 695 | |
| 696 | if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx, |
| 697 | rsa->_method_mod_n)) goto err; |
| 698 | |
| 699 | if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12)) |
| 700 | if (!BN_sub(ret, rsa->n, ret)) goto err; |
| 701 | |
| 702 | p=buf; |
| 703 | i=BN_bn2bin(ret,p); |
| 704 | |
| 705 | switch (padding) |
| 706 | { |
| 707 | case RSA_PKCS1_PADDING: |
| 708 | r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num); |
| 709 | break; |
| 710 | case RSA_X931_PADDING: |
| 711 | r=RSA_padding_check_X931(to,num,buf,i,num); |
| 712 | break; |
| 713 | case RSA_NO_PADDING: |
| 714 | r=RSA_padding_check_none(to,num,buf,i,num); |
| 715 | break; |
| 716 | default: |
| 717 | RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE); |
| 718 | goto err; |
| 719 | } |
| 720 | if (r < 0) |
| 721 | RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED); |
| 722 | |
| 723 | err: |
| 724 | if (ctx != NULL) |
| 725 | { |
| 726 | BN_CTX_end(ctx); |
| 727 | BN_CTX_free(ctx); |
| 728 | } |
| 729 | if (buf != NULL) |
| 730 | { |
| 731 | OPENSSL_cleanse(buf,num); |
| 732 | OPENSSL_free(buf); |
| 733 | } |
| 734 | return(r); |
| 735 | } |
| 736 | |
| 737 | static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx) |
| 738 | { |
| 739 | BIGNUM *r1,*m1,*vrfy; |
| 740 | BIGNUM local_dmp1,local_dmq1,local_c,local_r1; |
| 741 | BIGNUM *dmp1,*dmq1,*c,*pr1; |
| 742 | int ret=0; |
| 743 | |
| 744 | BN_CTX_start(ctx); |
| 745 | r1 = BN_CTX_get(ctx); |
| 746 | m1 = BN_CTX_get(ctx); |
| 747 | vrfy = BN_CTX_get(ctx); |
| 748 | |
| 749 | { |
| 750 | BIGNUM local_p, local_q; |
| 751 | BIGNUM *p = NULL, *q = NULL; |
| 752 | |
| 753 | /* Make sure BN_mod_inverse in Montgomery intialization uses the |
| 754 | * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set) |
| 755 | */ |
| 756 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 757 | { |
| 758 | BN_init(&local_p); |
| 759 | p = &local_p; |
| 760 | BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME); |
| 761 | |
| 762 | BN_init(&local_q); |
| 763 | q = &local_q; |
| 764 | BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME); |
| 765 | } |
| 766 | else |
| 767 | { |
| 768 | p = rsa->p; |
| 769 | q = rsa->q; |
| 770 | } |
| 771 | |
| 772 | if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) |
| 773 | { |
| 774 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx)) |
| 775 | goto err; |
| 776 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx)) |
| 777 | goto err; |
| 778 | } |
| 779 | } |
| 780 | |
| 781 | if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) |
| 782 | if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) |
| 783 | goto err; |
| 784 | |
| 785 | /* compute I mod q */ |
| 786 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 787 | { |
| 788 | c = &local_c; |
| 789 | BN_with_flags(c, I, BN_FLG_CONSTTIME); |
| 790 | if (!BN_mod(r1,c,rsa->q,ctx)) goto err; |
| 791 | } |
| 792 | else |
| 793 | { |
| 794 | if (!BN_mod(r1,I,rsa->q,ctx)) goto err; |
| 795 | } |
| 796 | |
| 797 | /* compute r1^dmq1 mod q */ |
| 798 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 799 | { |
| 800 | dmq1 = &local_dmq1; |
| 801 | BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME); |
| 802 | } |
| 803 | else |
| 804 | dmq1 = rsa->dmq1; |
| 805 | if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx, |
| 806 | rsa->_method_mod_q)) goto err; |
| 807 | |
| 808 | /* compute I mod p */ |
| 809 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 810 | { |
| 811 | c = &local_c; |
| 812 | BN_with_flags(c, I, BN_FLG_CONSTTIME); |
| 813 | if (!BN_mod(r1,c,rsa->p,ctx)) goto err; |
| 814 | } |
| 815 | else |
| 816 | { |
| 817 | if (!BN_mod(r1,I,rsa->p,ctx)) goto err; |
| 818 | } |
| 819 | |
| 820 | /* compute r1^dmp1 mod p */ |
| 821 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 822 | { |
| 823 | dmp1 = &local_dmp1; |
| 824 | BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME); |
| 825 | } |
| 826 | else |
| 827 | dmp1 = rsa->dmp1; |
| 828 | if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx, |
| 829 | rsa->_method_mod_p)) goto err; |
| 830 | |
| 831 | if (!BN_sub(r0,r0,m1)) goto err; |
| 832 | /* This will help stop the size of r0 increasing, which does |
| 833 | * affect the multiply if it optimised for a power of 2 size */ |
| 834 | if (BN_is_negative(r0)) |
| 835 | if (!BN_add(r0,r0,rsa->p)) goto err; |
| 836 | |
| 837 | if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err; |
| 838 | |
| 839 | /* Turn BN_FLG_CONSTTIME flag on before division operation */ |
| 840 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 841 | { |
| 842 | pr1 = &local_r1; |
| 843 | BN_with_flags(pr1, r1, BN_FLG_CONSTTIME); |
| 844 | } |
| 845 | else |
| 846 | pr1 = r1; |
| 847 | if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err; |
| 848 | |
| 849 | /* If p < q it is occasionally possible for the correction of |
| 850 | * adding 'p' if r0 is negative above to leave the result still |
| 851 | * negative. This can break the private key operations: the following |
| 852 | * second correction should *always* correct this rare occurrence. |
| 853 | * This will *never* happen with OpenSSL generated keys because |
| 854 | * they ensure p > q [steve] |
| 855 | */ |
| 856 | if (BN_is_negative(r0)) |
| 857 | if (!BN_add(r0,r0,rsa->p)) goto err; |
| 858 | if (!BN_mul(r1,r0,rsa->q,ctx)) goto err; |
| 859 | if (!BN_add(r0,r1,m1)) goto err; |
| 860 | |
| 861 | if (rsa->e && rsa->n) |
| 862 | { |
| 863 | if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err; |
| 864 | /* If 'I' was greater than (or equal to) rsa->n, the operation |
| 865 | * will be equivalent to using 'I mod n'. However, the result of |
| 866 | * the verify will *always* be less than 'n' so we don't check |
| 867 | * for absolute equality, just congruency. */ |
| 868 | if (!BN_sub(vrfy, vrfy, I)) goto err; |
| 869 | if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err; |
| 870 | if (BN_is_negative(vrfy)) |
| 871 | if (!BN_add(vrfy, vrfy, rsa->n)) goto err; |
| 872 | if (!BN_is_zero(vrfy)) |
| 873 | { |
| 874 | /* 'I' and 'vrfy' aren't congruent mod n. Don't leak |
| 875 | * miscalculated CRT output, just do a raw (slower) |
| 876 | * mod_exp and return that instead. */ |
| 877 | |
| 878 | BIGNUM local_d; |
| 879 | BIGNUM *d = NULL; |
| 880 | |
| 881 | if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) |
| 882 | { |
| 883 | d = &local_d; |
| 884 | BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME); |
| 885 | } |
| 886 | else |
| 887 | d = rsa->d; |
| 888 | if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx, |
| 889 | rsa->_method_mod_n)) goto err; |
| 890 | } |
| 891 | } |
| 892 | ret=1; |
| 893 | err: |
| 894 | BN_CTX_end(ctx); |
| 895 | return(ret); |
| 896 | } |
| 897 | |
| 898 | static int RSA_eay_init(RSA *rsa) |
| 899 | { |
| 900 | rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE; |
| 901 | return(1); |
| 902 | } |
| 903 | |
| 904 | static int RSA_eay_finish(RSA *rsa) |
| 905 | { |
| 906 | if (rsa->_method_mod_n != NULL) |
| 907 | BN_MONT_CTX_free(rsa->_method_mod_n); |
| 908 | if (rsa->_method_mod_p != NULL) |
| 909 | BN_MONT_CTX_free(rsa->_method_mod_p); |
| 910 | if (rsa->_method_mod_q != NULL) |
| 911 | BN_MONT_CTX_free(rsa->_method_mod_q); |
| 912 | return(1); |
| 913 | } |
| 914 | |
| 915 | #endif |