1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.]
57 /* ====================================================================
58 * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved.
60 * Redistribution and use in source and binary forms, with or without
61 * modification, are permitted provided that the following conditions
64 * 1. Redistributions of source code must retain the above copyright
65 * notice, this list of conditions and the following disclaimer.
67 * 2. Redistributions in binary form must reproduce the above copyright
68 * notice, this list of conditions and the following disclaimer in
69 * the documentation and/or other materials provided with the
72 * 3. All advertising materials mentioning features or use of this
73 * software must display the following acknowledgment:
74 * "This product includes software developed by the OpenSSL Project
75 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
78 * endorse or promote products derived from this software without
79 * prior written permission. For written permission, please contact
80 * openssl-core@openssl.org.
82 * 5. Products derived from this software may not be called "OpenSSL"
83 * nor may "OpenSSL" appear in their names without prior written
84 * permission of the OpenSSL Project.
86 * 6. Redistributions of any form whatsoever must retain the following
88 * "This product includes software developed by the OpenSSL Project
89 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
92 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
95 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
96 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
97 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
98 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
99 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
100 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
101 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
102 * OF THE POSSIBILITY OF SUCH DAMAGE.
103 * ====================================================================
105 * This product includes cryptographic software written by Eric Young
106 * (eay@cryptsoft.com). This product includes software written by Tim
107 * Hudson (tjh@cryptsoft.com).
111 #include "internal/cryptlib.h"
112 #include "internal/bn_int.h"
113 #include <openssl/rsa.h>
114 #include <openssl/rand.h>
118 static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
119 unsigned char *to, RSA *rsa, int padding);
120 static int rsa_ossl_private_encrypt(int flen, const unsigned char *from,
121 unsigned char *to, RSA *rsa, int padding);
122 static int rsa_ossl_public_decrypt(int flen, const unsigned char *from,
123 unsigned char *to, RSA *rsa, int padding);
124 static int rsa_ossl_private_decrypt(int flen, const unsigned char *from,
125 unsigned char *to, RSA *rsa, int padding);
126 static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa,
128 static int rsa_ossl_init(RSA *rsa);
129 static int rsa_ossl_finish(RSA *rsa);
130 static RSA_METHOD rsa_pkcs1_ossl_meth = {
131 "OpenSSL PKCS#1 RSA (from Eric Young)",
132 rsa_ossl_public_encrypt,
133 rsa_ossl_public_decrypt, /* signature verification */
134 rsa_ossl_private_encrypt, /* signing */
135 rsa_ossl_private_decrypt,
137 BN_mod_exp_mont, /* XXX probably we should not use Montgomery
141 RSA_FLAG_FIPS_METHOD, /* flags */
145 NULL /* rsa_keygen */
148 const RSA_METHOD *RSA_PKCS1_OpenSSL(void)
150 return &rsa_pkcs1_ossl_meth;
153 static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
154 unsigned char *to, RSA *rsa, int padding)
157 int i, j, k, num = 0, r = -1;
158 unsigned char *buf = NULL;
161 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
162 RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
166 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
167 RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
171 /* for large moduli, enforce exponent limit */
172 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
173 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
174 RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
179 if ((ctx = BN_CTX_new()) == NULL)
183 ret = BN_CTX_get(ctx);
184 num = BN_num_bytes(rsa->n);
185 buf = OPENSSL_malloc(num);
186 if (f == NULL || ret == NULL || buf == NULL) {
187 RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
192 case RSA_PKCS1_PADDING:
193 i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
195 case RSA_PKCS1_OAEP_PADDING:
196 i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
198 case RSA_SSLV23_PADDING:
199 i = RSA_padding_add_SSLv23(buf, num, from, flen);
202 i = RSA_padding_add_none(buf, num, from, flen);
205 RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
211 if (BN_bin2bn(buf, num, f) == NULL)
214 if (BN_ucmp(f, rsa->n) >= 0) {
215 /* usually the padding functions would catch this */
216 RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT,
217 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
221 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
222 if (!BN_MONT_CTX_set_locked
223 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
226 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
231 * put in leading 0 bytes if the number is less than the length of the
234 j = BN_num_bytes(ret);
235 i = BN_bn2bin(ret, &(to[num - j]));
236 for (k = 0; k < (num - i); k++)
244 OPENSSL_clear_free(buf, num);
248 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
251 int got_write_lock = 0;
254 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
256 if (rsa->blinding == NULL) {
257 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
258 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
261 if (rsa->blinding == NULL)
262 rsa->blinding = RSA_setup_blinding(rsa, ctx);
269 CRYPTO_THREADID_current(&cur);
270 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) {
271 /* rsa->blinding is ours! */
275 /* resort to rsa->mt_blinding instead */
278 * instructs rsa_blinding_convert(), rsa_blinding_invert() that the
279 * BN_BLINDING is shared, meaning that accesses require locks, and
280 * that the blinding factor must be stored outside the BN_BLINDING
284 if (rsa->mt_blinding == NULL) {
285 if (!got_write_lock) {
286 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
287 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
291 if (rsa->mt_blinding == NULL)
292 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
294 ret = rsa->mt_blinding;
299 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
301 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
305 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
310 * Local blinding: store the unblinding factor in BN_BLINDING.
312 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
315 * Shared blinding: store the unblinding factor outside BN_BLINDING.
318 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
319 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
320 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
325 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
329 * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
330 * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
331 * is shared between threads, unblind must be non-null:
332 * BN_BLINDING_invert_ex will then use the local unblinding factor, and
333 * will only read the modulus from BN_BLINDING. In both cases it's safe
334 * to access the blinding without a lock.
336 return BN_BLINDING_invert_ex(f, unblind, b, ctx);
340 static int rsa_ossl_private_encrypt(int flen, const unsigned char *from,
341 unsigned char *to, RSA *rsa, int padding)
343 BIGNUM *f, *ret, *res;
344 int i, j, k, num = 0, r = -1;
345 unsigned char *buf = NULL;
347 int local_blinding = 0;
349 * Used only if the blinding structure is shared. A non-NULL unblind
350 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
351 * the unblinding factor outside the blinding structure.
353 BIGNUM *unblind = NULL;
354 BN_BLINDING *blinding = NULL;
356 if ((ctx = BN_CTX_new()) == NULL)
360 ret = BN_CTX_get(ctx);
361 num = BN_num_bytes(rsa->n);
362 buf = OPENSSL_malloc(num);
363 if (f == NULL || ret == NULL || buf == NULL) {
364 RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
369 case RSA_PKCS1_PADDING:
370 i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
372 case RSA_X931_PADDING:
373 i = RSA_padding_add_X931(buf, num, from, flen);
376 i = RSA_padding_add_none(buf, num, from, flen);
378 case RSA_SSLV23_PADDING:
380 RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
386 if (BN_bin2bn(buf, num, f) == NULL)
389 if (BN_ucmp(f, rsa->n) >= 0) {
390 /* usually the padding functions would catch this */
391 RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT,
392 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
396 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
397 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
398 if (blinding == NULL) {
399 RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
404 if (blinding != NULL) {
405 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
406 RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
409 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
413 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
416 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
417 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
420 BIGNUM *d = NULL, *local_d = NULL;
422 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
423 local_d = d = BN_new();
425 RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
428 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
433 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
434 if (!BN_MONT_CTX_set_locked
435 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) {
440 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
441 rsa->_method_mod_n)) {
445 /* We MUST free local_d before any further use of rsa->d */
450 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
453 if (padding == RSA_X931_PADDING) {
454 BN_sub(f, rsa->n, ret);
455 if (BN_cmp(ret, f) > 0)
463 * put in leading 0 bytes if the number is less than the length of the
466 j = BN_num_bytes(res);
467 i = BN_bn2bin(res, &(to[num - j]));
468 for (k = 0; k < (num - i); k++)
476 OPENSSL_clear_free(buf, num);
480 static int rsa_ossl_private_decrypt(int flen, const unsigned char *from,
481 unsigned char *to, RSA *rsa, int padding)
484 int j, num = 0, r = -1;
486 unsigned char *buf = NULL;
488 int local_blinding = 0;
490 * Used only if the blinding structure is shared. A non-NULL unblind
491 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
492 * the unblinding factor outside the blinding structure.
494 BIGNUM *unblind = NULL;
495 BN_BLINDING *blinding = NULL;
497 if ((ctx = BN_CTX_new()) == NULL)
501 ret = BN_CTX_get(ctx);
502 num = BN_num_bytes(rsa->n);
503 buf = OPENSSL_malloc(num);
504 if (f == NULL || ret == NULL || buf == NULL) {
505 RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
510 * This check was for equality but PGP does evil things and chops off the
514 RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT,
515 RSA_R_DATA_GREATER_THAN_MOD_LEN);
519 /* make data into a big number */
520 if (BN_bin2bn(from, (int)flen, f) == NULL)
523 if (BN_ucmp(f, rsa->n) >= 0) {
524 RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT,
525 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
529 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
530 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
531 if (blinding == NULL) {
532 RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
537 if (blinding != NULL) {
538 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
539 RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
542 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
547 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
550 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
551 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
554 BIGNUM *d = NULL, *local_d = NULL;
556 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
557 local_d = d = BN_new();
559 RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
562 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
567 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
568 if (!BN_MONT_CTX_set_locked
569 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) {
573 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
574 rsa->_method_mod_n)) {
578 /* We MUST free local_d before any further use of rsa->d */
583 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
587 j = BN_bn2bin(ret, p); /* j is only used with no-padding mode */
590 case RSA_PKCS1_PADDING:
591 r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num);
593 case RSA_PKCS1_OAEP_PADDING:
594 r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
596 case RSA_SSLV23_PADDING:
597 r = RSA_padding_check_SSLv23(to, num, buf, j, num);
600 r = RSA_padding_check_none(to, num, buf, j, num);
603 RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
607 RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
613 OPENSSL_clear_free(buf, num);
617 /* signature verification */
618 static int rsa_ossl_public_decrypt(int flen, const unsigned char *from,
619 unsigned char *to, RSA *rsa, int padding)
622 int i, num = 0, r = -1;
624 unsigned char *buf = NULL;
627 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
628 RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
632 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
633 RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
637 /* for large moduli, enforce exponent limit */
638 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
639 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
640 RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
645 if ((ctx = BN_CTX_new()) == NULL)
649 ret = BN_CTX_get(ctx);
650 num = BN_num_bytes(rsa->n);
651 buf = OPENSSL_malloc(num);
652 if (f == NULL || ret == NULL || buf == NULL) {
653 RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
658 * This check was for equality but PGP does evil things and chops off the
662 RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN);
666 if (BN_bin2bn(from, flen, f) == NULL)
669 if (BN_ucmp(f, rsa->n) >= 0) {
670 RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT,
671 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
675 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
676 if (!BN_MONT_CTX_set_locked
677 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
680 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
684 if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12))
685 if (!BN_sub(ret, rsa->n, ret))
689 i = BN_bn2bin(ret, p);
692 case RSA_PKCS1_PADDING:
693 r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num);
695 case RSA_X931_PADDING:
696 r = RSA_padding_check_X931(to, num, buf, i, num);
699 r = RSA_padding_check_none(to, num, buf, i, num);
702 RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
706 RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
712 OPENSSL_clear_free(buf, num);
716 static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
718 BIGNUM *r1, *m1, *vrfy;
723 r1 = BN_CTX_get(ctx);
724 m1 = BN_CTX_get(ctx);
725 vrfy = BN_CTX_get(ctx);
728 BIGNUM *local_p = NULL, *local_q = NULL;
729 BIGNUM *p = NULL, *q = NULL;
732 * Make sure BN_mod_inverse in Montgomery initialization uses the
733 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
735 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
736 local_p = p = BN_new();
739 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
741 local_q = q = BN_new();
746 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
752 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
753 if (!BN_MONT_CTX_set_locked
754 (&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx)
755 || !BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
756 CRYPTO_LOCK_RSA, q, ctx)) {
763 * We MUST free local_p and local_q before any further use of rsa->p and
770 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
771 if (!BN_MONT_CTX_set_locked
772 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
775 /* compute I mod q */
777 BIGNUM *local_c = NULL;
779 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
783 BN_with_flags(local_c, I, BN_FLG_CONSTTIME);
788 if (!BN_mod(r1, c, rsa->q, ctx)) {
794 BIGNUM *local_dmq1 = NULL, *dmq1;
795 /* compute r1^dmq1 mod q */
796 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
797 dmq1 = local_dmq1 = BN_new();
798 if (local_dmq1 == NULL) {
802 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
806 if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx,
807 rsa->_method_mod_q)) {
812 /* We MUST free local_dmq1 before any further use of rsa->dmq1 */
816 /* compute I mod p */
817 if (!BN_mod(r1, c, rsa->p, ctx)) {
821 /* We MUST free local_c before any further use of I */
826 BIGNUM *local_dmp1 = NULL, *dmp1;
827 /* compute r1^dmp1 mod p */
828 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
829 dmp1 = local_dmp1 = BN_new();
830 if (local_dmp1 == NULL)
832 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
836 if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx,
837 rsa->_method_mod_p)) {
841 /* We MUST free local_dmp1 before any further use of rsa->dmp1 */
845 if (!BN_sub(r0, r0, m1))
848 * This will help stop the size of r0 increasing, which does affect the
849 * multiply if it optimised for a power of 2 size
851 if (BN_is_negative(r0))
852 if (!BN_add(r0, r0, rsa->p))
855 if (!BN_mul(r1, r0, rsa->iqmp, ctx))
859 BIGNUM *local_r1 = NULL, *pr1;
860 /* Turn BN_FLG_CONSTTIME flag on before division operation */
861 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
862 pr1 = local_r1 = BN_new();
863 if (local_r1 == NULL)
865 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
869 if (!BN_mod(r0, pr1, rsa->p, ctx)) {
873 /* We MUST free local_r1 before any further use of r1 */
878 * If p < q it is occasionally possible for the correction of adding 'p'
879 * if r0 is negative above to leave the result still negative. This can
880 * break the private key operations: the following second correction
881 * should *always* correct this rare occurrence. This will *never* happen
882 * with OpenSSL generated keys because they ensure p > q [steve]
884 if (BN_is_negative(r0))
885 if (!BN_add(r0, r0, rsa->p))
887 if (!BN_mul(r1, r0, rsa->q, ctx))
889 if (!BN_add(r0, r1, m1))
892 if (rsa->e && rsa->n) {
893 if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
897 * If 'I' was greater than (or equal to) rsa->n, the operation will
898 * be equivalent to using 'I mod n'. However, the result of the
899 * verify will *always* be less than 'n' so we don't check for
900 * absolute equality, just congruency.
902 if (!BN_sub(vrfy, vrfy, I))
904 if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
906 if (BN_is_negative(vrfy))
907 if (!BN_add(vrfy, vrfy, rsa->n))
909 if (!BN_is_zero(vrfy)) {
911 * 'I' and 'vrfy' aren't congruent mod n. Don't leak
912 * miscalculated CRT output, just do a raw (slower) mod_exp and
913 * return that instead.
916 BIGNUM *local_d = NULL;
919 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
920 local_d = d = BN_new();
923 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
927 if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
928 rsa->_method_mod_n)) {
932 /* We MUST free local_d before any further use of rsa->d */
942 static int rsa_ossl_init(RSA *rsa)
944 rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE;
948 static int rsa_ossl_finish(RSA *rsa)
950 BN_MONT_CTX_free(rsa->_method_mod_n);
951 BN_MONT_CTX_free(rsa->_method_mod_p);
952 BN_MONT_CTX_free(rsa->_method_mod_q);