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 "internal/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 case RSA_PKCS1_OAEP_PADDING:
197 i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
199 case RSA_SSLV23_PADDING:
200 i = RSA_padding_add_SSLv23(buf, num, from, flen);
203 i = RSA_padding_add_none(buf, num, from, flen);
206 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
212 if (BN_bin2bn(buf, num, f) == NULL)
215 if (BN_ucmp(f, rsa->n) >= 0) {
216 /* usually the padding functions would catch this */
217 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,
218 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
222 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
223 if (!BN_MONT_CTX_set_locked
224 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
227 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
232 * put in leading 0 bytes if the number is less than the length of the
235 j = BN_num_bytes(ret);
236 i = BN_bn2bin(ret, &(to[num - j]));
237 for (k = 0; k < (num - i); k++)
245 OPENSSL_clear_free(buf, num);
249 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
252 int got_write_lock = 0;
255 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
257 if (rsa->blinding == NULL) {
258 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
259 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
262 if (rsa->blinding == NULL)
263 rsa->blinding = RSA_setup_blinding(rsa, ctx);
270 CRYPTO_THREADID_current(&cur);
271 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) {
272 /* rsa->blinding is ours! */
276 /* resort to rsa->mt_blinding instead */
279 * instructs rsa_blinding_convert(), rsa_blinding_invert() that the
280 * BN_BLINDING is shared, meaning that accesses require locks, and
281 * that the blinding factor must be stored outside the BN_BLINDING
285 if (rsa->mt_blinding == NULL) {
286 if (!got_write_lock) {
287 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
288 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
292 if (rsa->mt_blinding == NULL)
293 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
295 ret = rsa->mt_blinding;
300 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
302 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
306 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
311 * Local blinding: store the unblinding factor in BN_BLINDING.
313 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
316 * Shared blinding: store the unblinding factor outside BN_BLINDING.
319 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
320 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
321 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
326 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
330 * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
331 * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
332 * is shared between threads, unblind must be non-null:
333 * BN_BLINDING_invert_ex will then use the local unblinding factor, and
334 * will only read the modulus from BN_BLINDING. In both cases it's safe
335 * to access the blinding without a lock.
337 return BN_BLINDING_invert_ex(f, unblind, b, ctx);
341 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
342 unsigned char *to, RSA *rsa, int padding)
344 BIGNUM *f, *ret, *res;
345 int i, j, k, num = 0, r = -1;
346 unsigned char *buf = NULL;
348 int local_blinding = 0;
350 * Used only if the blinding structure is shared. A non-NULL unblind
351 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
352 * the unblinding factor outside the blinding structure.
354 BIGNUM *unblind = NULL;
355 BN_BLINDING *blinding = NULL;
357 if ((ctx = BN_CTX_new()) == NULL)
361 ret = BN_CTX_get(ctx);
362 num = BN_num_bytes(rsa->n);
363 buf = OPENSSL_malloc(num);
364 if (!f || !ret || !buf) {
365 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
370 case RSA_PKCS1_PADDING:
371 i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
373 case RSA_X931_PADDING:
374 i = RSA_padding_add_X931(buf, num, from, flen);
377 i = RSA_padding_add_none(buf, num, from, flen);
379 case RSA_SSLV23_PADDING:
381 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
387 if (BN_bin2bn(buf, num, f) == NULL)
390 if (BN_ucmp(f, rsa->n) >= 0) {
391 /* usually the padding functions would catch this */
392 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,
393 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
397 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
398 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
399 if (blinding == NULL) {
400 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
405 if (blinding != NULL) {
406 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
407 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
410 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
414 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
417 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
418 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
421 BIGNUM *d = NULL, *local_d = NULL;
423 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
424 local_d = d = BN_new();
426 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
429 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)) {
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++)
475 OPENSSL_clear_free(buf, num);
479 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
480 unsigned char *to, RSA *rsa, int padding)
483 int j, num = 0, r = -1;
485 unsigned char *buf = NULL;
487 int local_blinding = 0;
489 * Used only if the blinding structure is shared. A non-NULL unblind
490 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
491 * the unblinding factor outside the blinding structure.
493 BIGNUM *unblind = NULL;
494 BN_BLINDING *blinding = NULL;
496 if ((ctx = BN_CTX_new()) == NULL)
500 ret = BN_CTX_get(ctx);
501 num = BN_num_bytes(rsa->n);
502 buf = OPENSSL_malloc(num);
503 if (!f || !ret || !buf) {
504 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
509 * This check was for equality but PGP does evil things and chops off the
513 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
514 RSA_R_DATA_GREATER_THAN_MOD_LEN);
518 /* make data into a big number */
519 if (BN_bin2bn(from, (int)flen, f) == NULL)
522 if (BN_ucmp(f, rsa->n) >= 0) {
523 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,
524 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
528 if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
529 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
530 if (blinding == NULL) {
531 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
536 if (blinding != NULL) {
537 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
538 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
541 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
546 if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
549 (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
550 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
553 BIGNUM *d = NULL, *local_d = NULL;
555 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
556 local_d = d = BN_new();
558 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
561 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
565 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
566 if (!BN_MONT_CTX_set_locked
567 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx)) {
571 if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
572 rsa->_method_mod_n)) {
580 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
584 j = BN_bn2bin(ret, p); /* j is only used with no-padding mode */
587 case RSA_PKCS1_PADDING:
588 r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num);
590 case RSA_PKCS1_OAEP_PADDING:
591 r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
593 case RSA_SSLV23_PADDING:
594 r = RSA_padding_check_SSLv23(to, num, buf, j, num);
597 r = RSA_padding_check_none(to, num, buf, j, num);
600 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
604 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
610 OPENSSL_clear_free(buf, num);
614 /* signature verification */
615 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
616 unsigned char *to, RSA *rsa, int padding)
619 int i, num = 0, r = -1;
621 unsigned char *buf = NULL;
624 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
625 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
629 if (BN_ucmp(rsa->n, rsa->e) <= 0) {
630 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
634 /* for large moduli, enforce exponent limit */
635 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
636 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
637 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
642 if ((ctx = BN_CTX_new()) == NULL)
646 ret = BN_CTX_get(ctx);
647 num = BN_num_bytes(rsa->n);
648 buf = OPENSSL_malloc(num);
649 if (!f || !ret || !buf) {
650 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
655 * This check was for equality but PGP does evil things and chops off the
659 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN);
663 if (BN_bin2bn(from, flen, f) == NULL)
666 if (BN_ucmp(f, rsa->n) >= 0) {
667 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,
668 RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
672 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
673 if (!BN_MONT_CTX_set_locked
674 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
677 if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
681 if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12))
682 if (!BN_sub(ret, rsa->n, ret))
686 i = BN_bn2bin(ret, p);
689 case RSA_PKCS1_PADDING:
690 r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num);
692 case RSA_X931_PADDING:
693 r = RSA_padding_check_X931(to, num, buf, i, num);
696 r = RSA_padding_check_none(to, num, buf, i, num);
699 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
703 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
709 OPENSSL_clear_free(buf, num);
713 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
715 BIGNUM *r1, *m1, *vrfy;
716 BIGNUM *local_dmp1, *local_dmq1, *local_c, *local_r1;
717 BIGNUM *dmp1, *dmq1, *c, *pr1;
722 local_dmp1 = BN_new();
723 local_dmq1 = BN_new();
726 if (!local_dmp1 || !local_dmq1 || !local_c || !local_r1)
729 r1 = BN_CTX_get(ctx);
730 m1 = BN_CTX_get(ctx);
731 vrfy = BN_CTX_get(ctx);
734 BIGNUM *local_p = NULL, *local_q = NULL;
735 BIGNUM *p = NULL, *q = NULL;
738 * Make sure BN_mod_inverse in Montgomery intialization uses the
739 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
741 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
742 local_p = p = BN_new();
745 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
747 local_q = q = BN_new();
752 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
758 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
759 if (!BN_MONT_CTX_set_locked
760 (&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx)
761 || !BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
762 CRYPTO_LOCK_RSA, q, ctx)) {
772 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
773 if (!BN_MONT_CTX_set_locked
774 (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
777 /* compute I mod q */
778 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
780 BN_with_flags(c, I, BN_FLG_CONSTTIME);
781 if (!BN_mod(r1, c, rsa->q, ctx))
784 if (!BN_mod(r1, I, rsa->q, ctx))
788 /* compute r1^dmq1 mod q */
789 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
791 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
794 if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, rsa->_method_mod_q))
797 /* compute I mod p */
798 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
800 BN_with_flags(c, I, BN_FLG_CONSTTIME);
801 if (!BN_mod(r1, c, rsa->p, ctx))
804 if (!BN_mod(r1, I, rsa->p, ctx))
808 /* compute r1^dmp1 mod p */
809 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
811 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
814 if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, rsa->_method_mod_p))
817 if (!BN_sub(r0, r0, m1))
820 * This will help stop the size of r0 increasing, which does affect the
821 * multiply if it optimised for a power of 2 size
823 if (BN_is_negative(r0))
824 if (!BN_add(r0, r0, rsa->p))
827 if (!BN_mul(r1, r0, rsa->iqmp, ctx))
830 /* Turn BN_FLG_CONSTTIME flag on before division operation */
831 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
833 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
836 if (!BN_mod(r0, pr1, rsa->p, ctx))
840 * If p < q it is occasionally possible for the correction of adding 'p'
841 * if r0 is negative above to leave the result still negative. This can
842 * break the private key operations: the following second correction
843 * should *always* correct this rare occurrence. This will *never* happen
844 * with OpenSSL generated keys because they ensure p > q [steve]
846 if (BN_is_negative(r0))
847 if (!BN_add(r0, r0, rsa->p))
849 if (!BN_mul(r1, r0, rsa->q, ctx))
851 if (!BN_add(r0, r1, m1))
854 if (rsa->e && rsa->n) {
855 if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
859 * If 'I' was greater than (or equal to) rsa->n, the operation will
860 * be equivalent to using 'I mod n'. However, the result of the
861 * verify will *always* be less than 'n' so we don't check for
862 * absolute equality, just congruency.
864 if (!BN_sub(vrfy, vrfy, I))
866 if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
868 if (BN_is_negative(vrfy))
869 if (!BN_add(vrfy, vrfy, rsa->n))
871 if (!BN_is_zero(vrfy)) {
873 * 'I' and 'vrfy' aren't congruent mod n. Don't leak
874 * miscalculated CRT output, just do a raw (slower) mod_exp and
875 * return that instead.
878 BIGNUM *local_d = NULL;
881 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
882 local_d = d = BN_new();
885 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
888 if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
889 rsa->_method_mod_n)) {
907 static int RSA_eay_init(RSA *rsa)
909 rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE;
913 static int RSA_eay_finish(RSA *rsa)
915 BN_MONT_CTX_free(rsa->_method_mod_n);
916 BN_MONT_CTX_free(rsa->_method_mod_p);
917 BN_MONT_CTX_free(rsa->_method_mod_q);