1 /* crypto/rsa/rsa_eay.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
58 /* ====================================================================
59 * Copyright (c) 1998-2018 The OpenSSL Project. All rights reserved.
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
87 * 6. Redistributions of any form whatsoever must retain the following
89 * "This product includes software developed by the OpenSSL Project
90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 * ====================================================================
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).
113 #include "cryptlib.h"
114 #include <openssl/bn.h>
115 #include <openssl/rsa.h>
116 #include <openssl/rand.h>
121 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
122 unsigned char *to, RSA *rsa, int padding);
123 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
124 unsigned char *to, RSA *rsa, int padding);
125 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
126 unsigned char *to, RSA *rsa, int padding);
127 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
128 unsigned char *to, RSA *rsa, int padding);
129 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa,
131 static int RSA_eay_init(RSA *rsa);
132 static int RSA_eay_finish(RSA *rsa);
133 static RSA_METHOD rsa_pkcs1_eay_meth = {
134 "Eric Young's PKCS#1 RSA",
135 RSA_eay_public_encrypt,
136 RSA_eay_public_decrypt, /* signature verification */
137 RSA_eay_private_encrypt, /* signing */
138 RSA_eay_private_decrypt,
140 BN_mod_exp_mont, /* XXX probably we should not use Montgomery
148 NULL /* rsa_keygen */
151 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
153 return (&rsa_pkcs1_eay_meth);
156 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
157 unsigned char *to, RSA *rsa, int padding)
160 int i, num = 0, r = -1;
161 unsigned char *buf = NULL;
164 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
165 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
169 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
170 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
174 /* for large moduli, enforce exponent limit */
175 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
176 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
177 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
182 if ((ctx = BN_CTX_new()) == NULL)
186 ret = BN_CTX_get(ctx);
187 num = BN_num_bytes(rsa->n);
188 buf = OPENSSL_malloc(num);
189 if (!f || !ret || !buf) {
190 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
195 case RSA_PKCS1_PADDING:
196 i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
198 # ifndef OPENSSL_NO_SHA
199 case RSA_PKCS1_OAEP_PADDING:
200 i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
203 case RSA_SSLV23_PADDING:
204 i = RSA_padding_add_SSLv23(buf, num, from, flen);
207 i = RSA_padding_add_none(buf, num, from, flen);
210 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
216 if (BN_bin2bn(buf, num, f) == NULL)
219 if (BN_ucmp(f, rsa->n) >= 0) {
220 /* usually the padding functions would catch this */
221 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,
222 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
226 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
227 if (!BN_MONT_CTX_set_locked
228 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
231 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
236 * BN_bn2binpad puts in leading 0 bytes if the number is less than
237 * the length of the modulus.
239 r = bn_bn2binpad(ret, to, num);
246 OPENSSL_cleanse(buf, num);
252 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
255 int got_write_lock = 0;
258 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
260 if (rsa->blinding == NULL) {
261 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
262 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
265 if (rsa->blinding == NULL)
266 rsa->blinding = RSA_setup_blinding(rsa, ctx);
273 CRYPTO_THREADID_current(&cur);
274 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) {
275 /* rsa->blinding is ours! */
279 /* resort to rsa->mt_blinding instead */
282 * instructs rsa_blinding_convert(), rsa_blinding_invert() that the
283 * BN_BLINDING is shared, meaning that accesses require locks, and
284 * that the blinding factor must be stored outside the BN_BLINDING
288 if (rsa->mt_blinding == NULL) {
289 if (!got_write_lock) {
290 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
291 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
295 if (rsa->mt_blinding == NULL)
296 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
298 ret = rsa->mt_blinding;
303 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
305 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
309 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
314 * Local blinding: store the unblinding factor in BN_BLINDING.
316 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
319 * Shared blinding: store the unblinding factor outside BN_BLINDING.
322 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
323 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
324 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
329 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
333 * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
334 * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
335 * is shared between threads, unblind must be non-null:
336 * BN_BLINDING_invert_ex will then use the local unblinding factor, and
337 * will only read the modulus from BN_BLINDING. In both cases it's safe
338 * to access the blinding without a lock.
340 return BN_BLINDING_invert_ex(f, unblind, b, ctx);
344 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
345 unsigned char *to, RSA *rsa, int padding)
347 BIGNUM *f, *ret, *res;
348 int i, num = 0, r = -1;
349 unsigned char *buf = NULL;
351 int local_blinding = 0;
353 * Used only if the blinding structure is shared. A non-NULL unblind
354 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
355 * the unblinding factor outside the blinding structure.
357 BIGNUM *unblind = NULL;
358 BN_BLINDING *blinding = NULL;
360 if ((ctx = BN_CTX_new()) == NULL)
364 ret = BN_CTX_get(ctx);
365 num = BN_num_bytes(rsa->n);
366 buf = OPENSSL_malloc(num);
367 if (!f || !ret || !buf) {
368 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
373 case RSA_PKCS1_PADDING:
374 i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
376 case RSA_X931_PADDING:
377 i = RSA_padding_add_X931(buf, num, from, flen);
380 i = RSA_padding_add_none(buf, num, from, flen);
382 case RSA_SSLV23_PADDING:
384 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
390 if (BN_bin2bn(buf, num, f) == NULL)
393 if (BN_ucmp(f, rsa->n) >= 0) {
394 /* usually the padding functions would catch this */
395 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
396 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
400 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
401 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
402 if (blinding == NULL) {
403 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
408 if (blinding != NULL) {
409 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
410 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
413 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
417 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
420 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
421 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
427 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
430 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
434 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
435 if (!BN_MONT_CTX_set_locked
436 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
439 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
445 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
448 if (padding == RSA_X931_PADDING) {
449 BN_sub(f, rsa->n, ret);
450 if (BN_cmp(ret, f) > 0)
458 * BN_bn2binpad puts in leading 0 bytes if the number is less than
459 * the length of the modulus.
461 r = bn_bn2binpad(res, to, num);
468 OPENSSL_cleanse(buf, num);
474 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
475 unsigned char *to, RSA *rsa, int padding)
478 int j, num = 0, r = -1;
479 unsigned char *buf = NULL;
481 int local_blinding = 0;
483 * Used only if the blinding structure is shared. A non-NULL unblind
484 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
485 * the unblinding factor outside the blinding structure.
487 BIGNUM *unblind = NULL;
488 BN_BLINDING *blinding = NULL;
490 if ((ctx = BN_CTX_new()) == NULL)
494 ret = BN_CTX_get(ctx);
495 num = BN_num_bytes(rsa->n);
496 buf = OPENSSL_malloc(num);
497 if (!f || !ret || !buf) {
498 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
503 * This check was for equality but PGP does evil things and chops off the
507 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
508 RSA_R_DATA_GREATER_THAN_MOD_LEN);
512 /* make data into a big number */
513 if (BN_bin2bn(from, (int)flen, f) == NULL)
516 if (BN_ucmp(f, rsa->n) >= 0) {
517 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
518 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
522 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
523 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
524 if (blinding == NULL) {
525 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
530 if (blinding != NULL) {
531 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
532 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
535 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
540 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
543 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
544 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
550 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
552 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
556 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
557 if (!BN_MONT_CTX_set_locked
558 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
560 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
566 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
569 j = bn_bn2binpad(ret, buf, num);
572 case RSA_PKCS1_PADDING:
573 r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num);
575 # ifndef OPENSSL_NO_SHA
576 case RSA_PKCS1_OAEP_PADDING:
577 r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
580 case RSA_SSLV23_PADDING:
581 r = RSA_padding_check_SSLv23(to, num, buf, j, num);
584 memcpy(to, buf, (r = j));
587 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
591 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
599 OPENSSL_cleanse(buf, num);
605 /* signature verification */
606 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
607 unsigned char *to, RSA *rsa, int padding)
610 int i, num = 0, r = -1;
611 unsigned char *buf = NULL;
614 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
615 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
619 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
620 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
624 /* for large moduli, enforce exponent limit */
625 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
626 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
627 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
632 if ((ctx = BN_CTX_new()) == NULL)
636 ret = BN_CTX_get(ctx);
637 num = BN_num_bytes(rsa->n);
638 buf = OPENSSL_malloc(num);
639 if (!f || !ret || !buf) {
640 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
645 * This check was for equality but PGP does evil things and chops off the
649 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN);
653 if (BN_bin2bn(from, flen, f) == NULL)
656 if (BN_ucmp(f, rsa->n) >= 0) {
657 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,
658 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
662 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
663 if (!BN_MONT_CTX_set_locked
664 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
667 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
671 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
672 if (!BN_sub(ret, rsa->n, ret))
675 i = bn_bn2binpad(ret, buf, num);
678 case RSA_PKCS1_PADDING:
679 r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num);
681 case RSA_X931_PADDING:
682 r = RSA_padding_check_X931(to, num, buf, i, num);
685 memcpy(to, buf, (r = i));
688 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
692 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
700 OPENSSL_cleanse(buf, num);
706 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
708 BIGNUM *r1, *m1, *vrfy;
709 BIGNUM local_dmp1, local_dmq1, local_c, local_r1;
710 BIGNUM *dmp1, *dmq1, *c, *pr1;
714 r1 = BN_CTX_get(ctx);
715 m1 = BN_CTX_get(ctx);
716 vrfy = BN_CTX_get(ctx);
719 BIGNUM local_p, local_q;
720 BIGNUM *p = NULL, *q = NULL;
723 * Make sure BN_mod_inverse in Montgomery intialization uses the
724 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
726 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
729 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
733 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
739 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
740 if (!BN_MONT_CTX_set_locked
741 (&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx))
743 if (!BN_MONT_CTX_set_locked
744 (&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
749 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
750 if (!BN_MONT_CTX_set_locked
751 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
754 /* compute I mod q */
755 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
757 BN_with_flags(c, I, BN_FLG_CONSTTIME);
758 if (!BN_mod(r1, c, rsa->q, ctx))
761 if (!BN_mod(r1, I, rsa->q, ctx))
765 /* compute r1^dmq1 mod q */
766 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
768 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
771 if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, rsa->_method_mod_q))
774 /* compute I mod p */
775 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
777 BN_with_flags(c, I, BN_FLG_CONSTTIME);
778 if (!BN_mod(r1, c, rsa->p, ctx))
781 if (!BN_mod(r1, I, rsa->p, ctx))
785 /* compute r1^dmp1 mod p */
786 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
788 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
791 if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, rsa->_method_mod_p))
794 if (!BN_sub(r0, r0, m1))
797 * This will help stop the size of r0 increasing, which does affect the
798 * multiply if it optimised for a power of 2 size
800 if (BN_is_negative(r0))
801 if (!BN_add(r0, r0, rsa->p))
804 if (!BN_mul(r1, r0, rsa->iqmp, ctx))
807 /* Turn BN_FLG_CONSTTIME flag on before division operation */
808 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
810 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
813 if (!BN_mod(r0, pr1, rsa->p, ctx))
817 * If p < q it is occasionally possible for the correction of adding 'p'
818 * if r0 is negative above to leave the result still negative. This can
819 * break the private key operations: the following second correction
820 * should *always* correct this rare occurrence. This will *never* happen
821 * with OpenSSL generated keys because they ensure p > q [steve]
823 if (BN_is_negative(r0))
824 if (!BN_add(r0, r0, rsa->p))
826 if (!BN_mul(r1, r0, rsa->q, ctx))
828 if (!BN_add(r0, r1, m1))
831 if (rsa->e && rsa->n) {
832 if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
836 * If 'I' was greater than (or equal to) rsa->n, the operation will
837 * be equivalent to using 'I mod n'. However, the result of the
838 * verify will *always* be less than 'n' so we don't check for
839 * absolute equality, just congruency.
841 if (!BN_sub(vrfy, vrfy, I))
843 if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
845 if (BN_is_negative(vrfy))
846 if (!BN_add(vrfy, vrfy, rsa->n))
848 if (!BN_is_zero(vrfy)) {
850 * 'I' and 'vrfy' aren't congruent mod n. Don't leak
851 * miscalculated CRT output, just do a raw (slower) mod_exp and
852 * return that instead.
858 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
860 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
863 if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
874 static int RSA_eay_init(RSA *rsa)
876 rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE;
880 static int RSA_eay_finish(RSA *rsa)
882 if (rsa->_method_mod_n != NULL)
883 BN_MONT_CTX_free(rsa->_method_mod_n);
884 if (rsa->_method_mod_p != NULL)
885 BN_MONT_CTX_free(rsa->_method_mod_p);
886 if (rsa->_method_mod_q != NULL)
887 BN_MONT_CTX_free(rsa->_method_mod_q);