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) 1998-2006 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>
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,
130 static int RSA_eay_init(RSA *rsa);
131 static int RSA_eay_finish(RSA *rsa);
132 static RSA_METHOD rsa_pkcs1_eay_meth = {
133 "Eric Young's PKCS#1 RSA",
134 RSA_eay_public_encrypt,
135 RSA_eay_public_decrypt, /* signature verification */
136 RSA_eay_private_encrypt, /* signing */
137 RSA_eay_private_decrypt,
139 BN_mod_exp_mont, /* XXX probably we should not use Montgomery
147 NULL /* rsa_keygen */
150 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
152 return (&rsa_pkcs1_eay_meth);
155 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
156 unsigned char *to, RSA *rsa, int padding)
159 int i, j, k, num = 0, r = -1;
160 unsigned char *buf = NULL;
163 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
164 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
168 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
169 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
173 /* for large moduli, enforce exponent limit */
174 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
175 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
176 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
181 if ((ctx = BN_CTX_new()) == NULL)
185 ret = BN_CTX_get(ctx);
186 num = BN_num_bytes(rsa->n);
187 buf = OPENSSL_malloc(num);
188 if (!f || !ret || !buf) {
189 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
194 case RSA_PKCS1_PADDING:
195 i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
197 # ifndef OPENSSL_NO_SHA
198 case RSA_PKCS1_OAEP_PADDING:
199 i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
202 case RSA_SSLV23_PADDING:
203 i = RSA_padding_add_SSLv23(buf, num, from, flen);
206 i = RSA_padding_add_none(buf, num, from, flen);
209 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
215 if (BN_bin2bn(buf, num, f) == NULL)
218 if (BN_ucmp(f, rsa->n) >= 0) {
219 /* usually the padding functions would catch this */
220 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,
221 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
225 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
226 if (!BN_MONT_CTX_set_locked
227 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
230 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
235 * put in leading 0 bytes if the number is less than the length of the
238 j = BN_num_bytes(ret);
239 i = BN_bn2bin(ret, &(to[num - j]));
240 for (k = 0; k < (num - i); k++)
250 OPENSSL_cleanse(buf, num);
256 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
259 int got_write_lock = 0;
262 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
264 if (rsa->blinding == NULL) {
265 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
266 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
269 if (rsa->blinding == NULL)
270 rsa->blinding = RSA_setup_blinding(rsa, ctx);
277 CRYPTO_THREADID_current(&cur);
278 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) {
279 /* rsa->blinding is ours! */
283 /* resort to rsa->mt_blinding instead */
286 * instructs rsa_blinding_convert(), rsa_blinding_invert() that the
287 * BN_BLINDING is shared, meaning that accesses require locks, and
288 * that the blinding factor must be stored outside the BN_BLINDING
292 if (rsa->mt_blinding == NULL) {
293 if (!got_write_lock) {
294 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
295 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
299 if (rsa->mt_blinding == NULL)
300 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
302 ret = rsa->mt_blinding;
307 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
309 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
313 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
318 * Local blinding: store the unblinding factor in BN_BLINDING.
320 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
323 * Shared blinding: store the unblinding factor outside BN_BLINDING.
326 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
327 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
328 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
333 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
337 * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
338 * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
339 * is shared between threads, unblind must be non-null:
340 * BN_BLINDING_invert_ex will then use the local unblinding factor, and
341 * will only read the modulus from BN_BLINDING. In both cases it's safe
342 * to access the blinding without a lock.
344 return BN_BLINDING_invert_ex(f, unblind, b, ctx);
348 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
349 unsigned char *to, RSA *rsa, int padding)
351 BIGNUM *f, *ret, *res;
352 int i, j, k, num = 0, r = -1;
353 unsigned char *buf = NULL;
355 int local_blinding = 0;
357 * Used only if the blinding structure is shared. A non-NULL unblind
358 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
359 * the unblinding factor outside the blinding structure.
361 BIGNUM *unblind = NULL;
362 BN_BLINDING *blinding = NULL;
364 if ((ctx = BN_CTX_new()) == NULL)
368 ret = BN_CTX_get(ctx);
369 num = BN_num_bytes(rsa->n);
370 buf = OPENSSL_malloc(num);
371 if (!f || !ret || !buf) {
372 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
377 case RSA_PKCS1_PADDING:
378 i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
380 case RSA_X931_PADDING:
381 i = RSA_padding_add_X931(buf, num, from, flen);
384 i = RSA_padding_add_none(buf, num, from, flen);
386 case RSA_SSLV23_PADDING:
388 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
394 if (BN_bin2bn(buf, num, f) == NULL)
397 if (BN_ucmp(f, rsa->n) >= 0) {
398 /* usually the padding functions would catch this */
399 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
400 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
404 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
405 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
406 if (blinding == NULL) {
407 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
412 if (blinding != NULL) {
413 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
414 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
417 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
421 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
424 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
425 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
431 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
434 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
438 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
439 if (!BN_MONT_CTX_set_locked
440 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
443 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
449 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
452 if (padding == RSA_X931_PADDING) {
453 BN_sub(f, rsa->n, ret);
454 if (BN_cmp(ret, f) > 0)
462 * put in leading 0 bytes if the number is less than the length of the
465 j = BN_num_bytes(res);
466 i = BN_bn2bin(res, &(to[num - j]));
467 for (k = 0; k < (num - i); k++)
477 OPENSSL_cleanse(buf, num);
483 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
484 unsigned char *to, RSA *rsa, int padding)
487 int j, num = 0, r = -1;
489 unsigned char *buf = NULL;
491 int local_blinding = 0;
493 * Used only if the blinding structure is shared. A non-NULL unblind
494 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
495 * the unblinding factor outside the blinding structure.
497 BIGNUM *unblind = NULL;
498 BN_BLINDING *blinding = NULL;
500 if ((ctx = BN_CTX_new()) == NULL)
504 ret = BN_CTX_get(ctx);
505 num = BN_num_bytes(rsa->n);
506 buf = OPENSSL_malloc(num);
507 if (!f || !ret || !buf) {
508 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
513 * This check was for equality but PGP does evil things and chops off the
517 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
518 RSA_R_DATA_GREATER_THAN_MOD_LEN);
522 /* make data into a big number */
523 if (BN_bin2bn(from, (int)flen, f) == NULL)
526 if (BN_ucmp(f, rsa->n) >= 0) {
527 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
528 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
532 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
533 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
534 if (blinding == NULL) {
535 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
540 if (blinding != NULL) {
541 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
542 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
545 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
550 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
553 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
554 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
560 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
562 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
566 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
567 if (!BN_MONT_CTX_set_locked
568 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
570 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
576 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
580 j = BN_bn2bin(ret, p); /* j is only used with no-padding mode */
583 case RSA_PKCS1_PADDING:
584 r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num);
586 # ifndef OPENSSL_NO_SHA
587 case RSA_PKCS1_OAEP_PADDING:
588 r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
591 case RSA_SSLV23_PADDING:
592 r = RSA_padding_check_SSLv23(to, num, buf, j, num);
595 r = RSA_padding_check_none(to, num, buf, j, num);
598 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
602 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
610 OPENSSL_cleanse(buf, num);
616 /* signature verification */
617 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
618 unsigned char *to, RSA *rsa, int padding)
621 int i, num = 0, r = -1;
623 unsigned char *buf = NULL;
626 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
627 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
631 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
632 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
636 /* for large moduli, enforce exponent limit */
637 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
638 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
639 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
644 if ((ctx = BN_CTX_new()) == NULL)
648 ret = BN_CTX_get(ctx);
649 num = BN_num_bytes(rsa->n);
650 buf = OPENSSL_malloc(num);
651 if (!f || !ret || !buf) {
652 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
657 * This check was for equality but PGP does evil things and chops off the
661 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN);
665 if (BN_bin2bn(from, flen, f) == NULL)
668 if (BN_ucmp(f, rsa->n) >= 0) {
669 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,
670 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
674 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
675 if (!BN_MONT_CTX_set_locked
676 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
679 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
683 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
684 if (!BN_sub(ret, rsa->n, ret))
688 i = BN_bn2bin(ret, p);
691 case RSA_PKCS1_PADDING:
692 r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num);
694 case RSA_X931_PADDING:
695 r = RSA_padding_check_X931(to, num, buf, i, num);
698 r = RSA_padding_check_none(to, num, buf, i, num);
701 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
705 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
713 OPENSSL_cleanse(buf, num);
719 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
721 BIGNUM *r1, *m1, *vrfy;
722 BIGNUM local_dmp1, local_dmq1, local_c, local_r1;
723 BIGNUM *dmp1, *dmq1, *c, *pr1;
727 r1 = BN_CTX_get(ctx);
728 m1 = BN_CTX_get(ctx);
729 vrfy = BN_CTX_get(ctx);
732 BIGNUM local_p, local_q;
733 BIGNUM *p = NULL, *q = NULL;
736 * Make sure BN_mod_inverse in Montgomery intialization uses the
737 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
739 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
742 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
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))
756 if (!BN_MONT_CTX_set_locked
757 (&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
762 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
763 if (!BN_MONT_CTX_set_locked
764 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
767 /* compute I mod q */
768 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
770 BN_with_flags(c, I, BN_FLG_CONSTTIME);
771 if (!BN_mod(r1, c, rsa->q, ctx))
774 if (!BN_mod(r1, I, rsa->q, ctx))
778 /* compute r1^dmq1 mod q */
779 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
781 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
784 if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, rsa->_method_mod_q))
787 /* compute I mod p */
788 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
790 BN_with_flags(c, I, BN_FLG_CONSTTIME);
791 if (!BN_mod(r1, c, rsa->p, ctx))
794 if (!BN_mod(r1, I, rsa->p, ctx))
798 /* compute r1^dmp1 mod p */
799 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
801 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
804 if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, rsa->_method_mod_p))
807 if (!BN_sub(r0, r0, m1))
810 * This will help stop the size of r0 increasing, which does affect the
811 * multiply if it optimised for a power of 2 size
813 if (BN_is_negative(r0))
814 if (!BN_add(r0, r0, rsa->p))
817 if (!BN_mul(r1, r0, rsa->iqmp, ctx))
820 /* Turn BN_FLG_CONSTTIME flag on before division operation */
821 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
823 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
826 if (!BN_mod(r0, pr1, rsa->p, ctx))
830 * If p < q it is occasionally possible for the correction of adding 'p'
831 * if r0 is negative above to leave the result still negative. This can
832 * break the private key operations: the following second correction
833 * should *always* correct this rare occurrence. This will *never* happen
834 * with OpenSSL generated keys because they ensure p > q [steve]
836 if (BN_is_negative(r0))
837 if (!BN_add(r0, r0, rsa->p))
839 if (!BN_mul(r1, r0, rsa->q, ctx))
841 if (!BN_add(r0, r1, m1))
844 if (rsa->e && rsa->n) {
845 if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
849 * If 'I' was greater than (or equal to) rsa->n, the operation will
850 * be equivalent to using 'I mod n'. However, the result of the
851 * verify will *always* be less than 'n' so we don't check for
852 * absolute equality, just congruency.
854 if (!BN_sub(vrfy, vrfy, I))
856 if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
858 if (BN_is_negative(vrfy))
859 if (!BN_add(vrfy, vrfy, rsa->n))
861 if (!BN_is_zero(vrfy)) {
863 * 'I' and 'vrfy' aren't congruent mod n. Don't leak
864 * miscalculated CRT output, just do a raw (slower) mod_exp and
865 * return that instead.
871 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
873 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
876 if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
887 static int RSA_eay_init(RSA *rsa)
889 rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE;
893 static int RSA_eay_finish(RSA *rsa)
895 if (rsa->_method_mod_n != NULL)
896 BN_MONT_CTX_free(rsa->_method_mod_n);
897 if (rsa->_method_mod_p != NULL)
898 BN_MONT_CTX_free(rsa->_method_mod_p);
899 if (rsa->_method_mod_q != NULL)
900 BN_MONT_CTX_free(rsa->_method_mod_q);