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) > 0)
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