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).
112 #include "cryptlib.h"
113 #include "internal/bn_int.h"
114 #include <openssl/rsa.h>
115 #include <openssl/rand.h>
119 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
120 unsigned char *to, RSA *rsa, int padding);
121 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
122 unsigned char *to, RSA *rsa, int padding);
123 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
124 unsigned char *to, RSA *rsa, int padding);
125 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
126 unsigned char *to, RSA *rsa, int padding);
127 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa,
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,
138 BN_mod_exp_mont, /* XXX probably we should not use Montgomery
142 RSA_FLAG_FIPS_METHOD, /* flags */
146 NULL /* rsa_keygen */
149 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
151 return (&rsa_pkcs1_eay_meth);
154 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
155 unsigned char *to, RSA *rsa, int padding)
158 int i, j, k, num = 0, r = -1;
159 unsigned char *buf = NULL;
162 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
163 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
167 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
168 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
172 /* for large moduli, enforce exponent limit */
173 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
174 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
175 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
180 if ((ctx = BN_CTX_new()) == NULL)
184 ret = BN_CTX_get(ctx);
185 num = BN_num_bytes(rsa->n);
186 buf = OPENSSL_malloc(num);
187 if (!f || !ret || !buf) {
188 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
193 case RSA_PKCS1_PADDING:
194 i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
196 # ifndef OPENSSL_NO_SHA
197 case RSA_PKCS1_OAEP_PADDING:
198 i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
201 case RSA_SSLV23_PADDING:
202 i = RSA_padding_add_SSLv23(buf, num, from, flen);
205 i = RSA_padding_add_none(buf, num, from, flen);
208 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
214 if (BN_bin2bn(buf, num, f) == NULL)
217 if (BN_ucmp(f, rsa->n) >= 0) {
218 /* usually the padding functions would catch this */
219 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,
220 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
224 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
225 if (!BN_MONT_CTX_set_locked
226 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
229 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
234 * put in leading 0 bytes if the number is less than the length of the
237 j = BN_num_bytes(ret);
238 i = BN_bn2bin(ret, &(to[num - j]));
239 for (k = 0; k < (num - i); k++)
249 OPENSSL_cleanse(buf, num);
255 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
258 int got_write_lock = 0;
261 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
263 if (rsa->blinding == NULL) {
264 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
265 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
268 if (rsa->blinding == NULL)
269 rsa->blinding = RSA_setup_blinding(rsa, ctx);
276 CRYPTO_THREADID_current(&cur);
277 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) {
278 /* rsa->blinding is ours! */
282 /* resort to rsa->mt_blinding instead */
285 * instructs rsa_blinding_convert(), rsa_blinding_invert() that the
286 * BN_BLINDING is shared, meaning that accesses require locks, and
287 * that the blinding factor must be stored outside the BN_BLINDING
291 if (rsa->mt_blinding == NULL) {
292 if (!got_write_lock) {
293 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
294 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
298 if (rsa->mt_blinding == NULL)
299 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
301 ret = rsa->mt_blinding;
306 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
308 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
312 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
317 * Local blinding: store the unblinding factor in BN_BLINDING.
319 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
322 * Shared blinding: store the unblinding factor outside BN_BLINDING.
325 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
326 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
327 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
332 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
336 * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
337 * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
338 * is shared between threads, unblind must be non-null:
339 * BN_BLINDING_invert_ex will then use the local unblinding factor, and
340 * will only read the modulus from BN_BLINDING. In both cases it's safe
341 * to access the blinding without a lock.
343 return BN_BLINDING_invert_ex(f, unblind, b, ctx);
347 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
348 unsigned char *to, RSA *rsa, int padding)
350 BIGNUM *f, *ret, *res;
351 int i, j, k, num = 0, r = -1;
352 unsigned char *buf = NULL;
354 int local_blinding = 0;
356 * Used only if the blinding structure is shared. A non-NULL unblind
357 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
358 * the unblinding factor outside the blinding structure.
360 BIGNUM *unblind = NULL;
361 BN_BLINDING *blinding = NULL;
363 if ((ctx = BN_CTX_new()) == NULL)
367 ret = BN_CTX_get(ctx);
368 num = BN_num_bytes(rsa->n);
369 buf = OPENSSL_malloc(num);
370 if (!f || !ret || !buf) {
371 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
376 case RSA_PKCS1_PADDING:
377 i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
379 case RSA_X931_PADDING:
380 i = RSA_padding_add_X931(buf, num, from, flen);
383 i = RSA_padding_add_none(buf, num, from, flen);
385 case RSA_SSLV23_PADDING:
387 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
393 if (BN_bin2bn(buf, num, f) == NULL)
396 if (BN_ucmp(f, rsa->n) >= 0) {
397 /* usually the padding functions would catch this */
398 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
399 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
403 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
404 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
405 if (blinding == NULL) {
406 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
411 if (blinding != NULL) {
412 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
413 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
416 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
420 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
423 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
424 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
427 BIGNUM *d = NULL, *local_d = NULL;
429 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
430 local_d = d = BN_new();
432 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
435 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
439 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
440 if (!BN_MONT_CTX_set_locked
441 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) {
447 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
448 rsa->_method_mod_n)) {
458 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
461 if (padding == RSA_X931_PADDING) {
462 BN_sub(f, rsa->n, ret);
463 if (BN_cmp(ret, f) > 0)
471 * put in leading 0 bytes if the number is less than the length of the
474 j = BN_num_bytes(res);
475 i = BN_bn2bin(res, &(to[num - j]));
476 for (k = 0; k < (num - i); k++)
486 OPENSSL_cleanse(buf, num);
492 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
493 unsigned char *to, RSA *rsa, int padding)
496 int j, num = 0, r = -1;
498 unsigned char *buf = NULL;
500 int local_blinding = 0;
502 * Used only if the blinding structure is shared. A non-NULL unblind
503 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
504 * the unblinding factor outside the blinding structure.
506 BIGNUM *unblind = NULL;
507 BN_BLINDING *blinding = NULL;
509 if ((ctx = BN_CTX_new()) == NULL)
513 ret = BN_CTX_get(ctx);
514 num = BN_num_bytes(rsa->n);
515 buf = OPENSSL_malloc(num);
516 if (!f || !ret || !buf) {
517 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
522 * This check was for equality but PGP does evil things and chops off the
526 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
527 RSA_R_DATA_GREATER_THAN_MOD_LEN);
531 /* make data into a big number */
532 if (BN_bin2bn(from, (int)flen, f) == NULL)
535 if (BN_ucmp(f, rsa->n) >= 0) {
536 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
537 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
541 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
542 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
543 if (blinding == NULL) {
544 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
549 if (blinding != NULL) {
550 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
551 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
554 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
559 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
562 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
563 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
566 BIGNUM *d = NULL, *local_d = NULL;
568 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
569 local_d = d = BN_new();
571 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
574 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
578 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
579 if (!BN_MONT_CTX_set_locked
580 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) {
585 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
586 rsa->_method_mod_n)) {
596 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
600 j = BN_bn2bin(ret, p); /* j is only used with no-padding mode */
603 case RSA_PKCS1_PADDING:
604 r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num);
606 # ifndef OPENSSL_NO_SHA
607 case RSA_PKCS1_OAEP_PADDING:
608 r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
611 case RSA_SSLV23_PADDING:
612 r = RSA_padding_check_SSLv23(to, num, buf, j, num);
615 r = RSA_padding_check_none(to, num, buf, j, num);
618 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
622 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
630 OPENSSL_cleanse(buf, num);
636 /* signature verification */
637 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
638 unsigned char *to, RSA *rsa, int padding)
641 int i, num = 0, r = -1;
643 unsigned char *buf = NULL;
646 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
647 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
651 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
652 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
656 /* for large moduli, enforce exponent limit */
657 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
658 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
659 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
664 if ((ctx = BN_CTX_new()) == NULL)
668 ret = BN_CTX_get(ctx);
669 num = BN_num_bytes(rsa->n);
670 buf = OPENSSL_malloc(num);
671 if (!f || !ret || !buf) {
672 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
677 * This check was for equality but PGP does evil things and chops off the
681 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN);
685 if (BN_bin2bn(from, flen, f) == NULL)
688 if (BN_ucmp(f, rsa->n) >= 0) {
689 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,
690 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
694 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
695 if (!BN_MONT_CTX_set_locked
696 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
699 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
703 if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12))
704 if (!BN_sub(ret, rsa->n, ret))
708 i = BN_bn2bin(ret, p);
711 case RSA_PKCS1_PADDING:
712 r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num);
714 case RSA_X931_PADDING:
715 r = RSA_padding_check_X931(to, num, buf, i, num);
718 r = RSA_padding_check_none(to, num, buf, i, num);
721 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
725 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
733 OPENSSL_cleanse(buf, num);
739 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
741 BIGNUM *r1, *m1, *vrfy;
742 BIGNUM *local_dmp1, *local_dmq1, *local_c, *local_r1;
743 BIGNUM *dmp1, *dmq1, *c, *pr1;
746 local_dmp1 = BN_new();
747 local_dmq1 = BN_new();
750 if (!local_dmp1 || !local_dmq1 || !local_c || !local_r1)
754 r1 = BN_CTX_get(ctx);
755 m1 = BN_CTX_get(ctx);
756 vrfy = BN_CTX_get(ctx);
759 BIGNUM *local_p = NULL, *local_q = NULL;
760 BIGNUM *p = NULL, *q = NULL;
763 * Make sure BN_mod_inverse in Montgomery intialization uses the
764 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
766 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
767 local_p = p = BN_new();
770 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
772 local_q = q = BN_new();
777 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
783 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
784 if (!BN_MONT_CTX_set_locked
785 (&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx)
786 || !BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
787 CRYPTO_LOCK_RSA, q, ctx)) {
801 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
802 if (!BN_MONT_CTX_set_locked
803 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
806 /* compute I mod q */
807 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
809 BN_with_flags(c, I, BN_FLG_CONSTTIME);
810 if (!BN_mod(r1, c, rsa->q, ctx))
813 if (!BN_mod(r1, I, rsa->q, ctx))
817 /* compute r1^dmq1 mod q */
818 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
820 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
823 if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, rsa->_method_mod_q))
826 /* compute I mod p */
827 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
829 BN_with_flags(c, I, BN_FLG_CONSTTIME);
830 if (!BN_mod(r1, c, rsa->p, ctx))
833 if (!BN_mod(r1, I, rsa->p, ctx))
837 /* compute r1^dmp1 mod p */
838 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
840 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
843 if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, rsa->_method_mod_p))
846 if (!BN_sub(r0, r0, m1))
849 * This will help stop the size of r0 increasing, which does affect the
850 * multiply if it optimised for a power of 2 size
852 if (BN_is_negative(r0))
853 if (!BN_add(r0, r0, rsa->p))
856 if (!BN_mul(r1, r0, rsa->iqmp, ctx))
859 /* Turn BN_FLG_CONSTTIME flag on before division operation */
860 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
862 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
865 if (!BN_mod(r0, pr1, rsa->p, ctx))
869 * If p < q it is occasionally possible for the correction of adding 'p'
870 * if r0 is negative above to leave the result still negative. This can
871 * break the private key operations: the following second correction
872 * should *always* correct this rare occurrence. This will *never* happen
873 * with OpenSSL generated keys because they ensure p > q [steve]
875 if (BN_is_negative(r0))
876 if (!BN_add(r0, r0, rsa->p))
878 if (!BN_mul(r1, r0, rsa->q, ctx))
880 if (!BN_add(r0, r1, m1))
883 if (rsa->e && rsa->n) {
885 meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
889 * If 'I' was greater than (or equal to) rsa->n, the operation will
890 * be equivalent to using 'I mod n'. However, the result of the
891 * verify will *always* be less than 'n' so we don't check for
892 * absolute equality, just congruency.
894 if (!BN_sub(vrfy, vrfy, I))
896 if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
898 if (BN_is_negative(vrfy))
899 if (!BN_add(vrfy, vrfy, rsa->n))
901 if (!BN_is_zero(vrfy)) {
903 * 'I' and 'vrfy' aren't congruent mod n. Don't leak
904 * miscalculated CRT output, just do a raw (slower) mod_exp and
905 * return that instead.
908 BIGNUM *local_d = NULL;
911 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
912 local_d = d = BN_new();
915 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
918 if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
919 rsa->_method_mod_n)) {
943 static int RSA_eay_init(RSA *rsa)
945 rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE;
949 static int RSA_eay_finish(RSA *rsa)
951 if (rsa->_method_mod_n != NULL)
952 BN_MONT_CTX_free(rsa->_method_mod_n);
953 if (rsa->_method_mod_p != NULL)
954 BN_MONT_CTX_free(rsa->_method_mod_p);
955 if (rsa->_method_mod_q != NULL)
956 BN_MONT_CTX_free(rsa->_method_mod_q);