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).
114 #include "cryptlib.h"
115 #include <openssl/bn.h>
116 #include <openssl/rsa.h>
117 #include <openssl/rand.h>
119 #if !defined(RSA_NULL) && !defined(OPENSSL_FIPS)
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, BN_CTX *ctx);
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 if e == 3 */
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)
164 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
168 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)
177 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
179 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
184 if ((ctx=BN_CTX_new()) == NULL) goto err;
187 ret = BN_CTX_get(ctx);
188 num=BN_num_bytes(rsa->n);
189 buf = OPENSSL_malloc(num);
190 if (!f || !ret || !buf)
192 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
198 case RSA_PKCS1_PADDING:
199 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
201 #ifndef OPENSSL_NO_SHA
202 case RSA_PKCS1_OAEP_PADDING:
203 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
206 case RSA_SSLV23_PADDING:
207 i=RSA_padding_add_SSLv23(buf,num,from,flen);
210 i=RSA_padding_add_none(buf,num,from,flen);
213 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
216 if (i <= 0) goto err;
218 if (BN_bin2bn(buf,num,f) == NULL) goto err;
220 if (BN_ucmp(f, rsa->n) >= 0)
222 /* usually the padding functions would catch this */
223 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
227 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
228 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
231 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
232 rsa->_method_mod_n)) goto err;
234 /* put in leading 0 bytes if the number is less than the
235 * length of the modulus */
237 i=BN_bn2bin(ret,&(to[num-j]));
238 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;
261 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
263 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 if (BN_BLINDING_get_thread_id(ret) == CRYPTO_thread_id())
279 /* rsa->blinding is ours! */
285 /* resort to rsa->mt_blinding instead */
287 *local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert()
288 * that the BN_BLINDING is shared, meaning that accesses
289 * require locks, and that the blinding factor must be
290 * stored outside the BN_BLINDING
293 if (rsa->mt_blinding == NULL)
297 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
298 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
302 if (rsa->mt_blinding == NULL)
303 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
305 ret = rsa->mt_blinding;
310 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
312 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
316 static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f,
317 BIGNUM *r, BN_CTX *ctx)
320 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
324 CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING);
325 ret = BN_BLINDING_convert_ex(f, r, b, ctx);
326 CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING);
331 static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f,
332 BIGNUM *r, BN_CTX *ctx)
335 return BN_BLINDING_invert_ex(f, NULL, b, ctx);
339 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
340 ret = BN_BLINDING_invert_ex(f, r, b, ctx);
341 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
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, *br, *res;
351 int i,j,k,num=0,r= -1;
352 unsigned char *buf=NULL;
354 int local_blinding = 0;
355 BN_BLINDING *blinding = NULL;
357 if ((ctx=BN_CTX_new()) == NULL) goto err;
360 br = BN_CTX_get(ctx);
361 ret = BN_CTX_get(ctx);
362 num = BN_num_bytes(rsa->n);
363 buf = OPENSSL_malloc(num);
364 if(!f || !ret || !buf)
366 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
372 case RSA_PKCS1_PADDING:
373 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
375 case RSA_X931_PADDING:
376 i=RSA_padding_add_X931(buf,num,from,flen);
379 i=RSA_padding_add_none(buf,num,from,flen);
381 case RSA_SSLV23_PADDING:
383 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
386 if (i <= 0) goto err;
388 if (BN_bin2bn(buf,num,f) == NULL) goto err;
390 if (BN_ucmp(f, rsa->n) >= 0)
392 /* usually the padding functions would catch this */
393 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
397 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
399 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
400 if (blinding == NULL)
402 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
407 if (blinding != NULL)
408 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
411 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
414 (rsa->dmp1 != NULL) &&
415 (rsa->dmq1 != NULL) &&
416 (rsa->iqmp != NULL)) )
418 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
425 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
429 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
434 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
435 if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
438 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
439 rsa->_method_mod_n)) goto err;
443 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
446 if (padding == RSA_X931_PADDING)
448 BN_sub(f, rsa->n, ret);
457 /* put in leading 0 bytes if the number is less than the
458 * length of the modulus */
460 i=BN_bn2bin(res,&(to[num-j]));
461 for (k=0; k<(num-i); k++)
473 OPENSSL_cleanse(buf,num);
479 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
480 unsigned char *to, RSA *rsa, int padding)
482 BIGNUM *f, *ret, *br;
485 unsigned char *buf=NULL;
487 int local_blinding = 0;
488 BN_BLINDING *blinding = NULL;
490 if((ctx = BN_CTX_new()) == NULL) goto err;
493 br = BN_CTX_get(ctx);
494 ret = BN_CTX_get(ctx);
495 num = BN_num_bytes(rsa->n);
496 buf = OPENSSL_malloc(num);
497 if(!f || !ret || !buf)
499 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
503 /* This check was for equality but PGP does evil things
504 * and chops off the top '0' bytes */
507 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
511 /* make data into a big number */
512 if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
514 if (BN_ucmp(f, rsa->n) >= 0)
516 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
520 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
522 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
523 if (blinding == NULL)
525 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
530 if (blinding != NULL)
531 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
535 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
538 (rsa->dmp1 != NULL) &&
539 (rsa->dmq1 != NULL) &&
540 (rsa->iqmp != NULL)) )
542 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
549 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
552 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
557 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
558 if (!BN_MONT_CTX_set_locked(&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, local_blinding, ret, br, ctx))
570 j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
574 case RSA_PKCS1_PADDING:
575 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
577 #ifndef OPENSSL_NO_SHA
578 case RSA_PKCS1_OAEP_PADDING:
579 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
582 case RSA_SSLV23_PADDING:
583 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
586 r=RSA_padding_check_none(to,num,buf,j,num);
589 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
593 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
603 OPENSSL_cleanse(buf,num);
609 /* signature verification */
610 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
611 unsigned char *to, RSA *rsa, int padding)
616 unsigned char *buf=NULL;
619 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
621 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
625 if (BN_ucmp(rsa->n, rsa->e) <= 0)
627 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
631 /* for large moduli, enforce exponent limit */
632 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
634 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
636 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
641 if((ctx = BN_CTX_new()) == NULL) goto err;
644 ret = BN_CTX_get(ctx);
645 num=BN_num_bytes(rsa->n);
646 buf = OPENSSL_malloc(num);
647 if(!f || !ret || !buf)
649 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
653 /* This check was for equality but PGP does evil things
654 * and chops off the top '0' bytes */
657 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
661 if (BN_bin2bn(from,flen,f) == NULL) goto err;
663 if (BN_ucmp(f, rsa->n) >= 0)
665 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
669 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
670 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
673 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
674 rsa->_method_mod_n)) goto err;
676 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
677 BN_sub(ret, rsa->n, ret);
684 case RSA_PKCS1_PADDING:
685 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
687 case RSA_X931_PADDING:
688 r=RSA_padding_check_X931(to,num,buf,i,num);
691 r=RSA_padding_check_none(to,num,buf,i,num);
694 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
698 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
708 OPENSSL_cleanse(buf,num);
714 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
716 BIGNUM *r1,*m1,*vrfy;
717 BIGNUM local_dmp1,local_dmq1,local_c,local_r1;
718 BIGNUM *dmp1,*dmq1,*c,*pr1;
722 r1 = BN_CTX_get(ctx);
723 m1 = BN_CTX_get(ctx);
724 vrfy = BN_CTX_get(ctx);
727 BIGNUM local_p, local_q;
728 BIGNUM *p = NULL, *q = NULL;
730 /* Make sure BN_mod_inverse in Montgomery intialization uses the
731 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
733 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
737 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
741 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
749 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
751 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx))
753 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
758 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
759 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
762 /* compute I mod q */
763 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
766 BN_with_flags(c, I, BN_FLG_CONSTTIME);
767 if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
771 if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
774 /* compute r1^dmq1 mod q */
775 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
778 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
782 if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
783 rsa->_method_mod_q)) goto err;
785 /* compute I mod p */
786 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
789 BN_with_flags(c, I, BN_FLG_CONSTTIME);
790 if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
794 if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
797 /* compute r1^dmp1 mod p */
798 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
801 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
805 if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
806 rsa->_method_mod_p)) goto err;
808 if (!BN_sub(r0,r0,m1)) goto err;
809 /* This will help stop the size of r0 increasing, which does
810 * affect the multiply if it optimised for a power of 2 size */
811 if (BN_is_negative(r0))
812 if (!BN_add(r0,r0,rsa->p)) goto err;
814 if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
816 /* Turn BN_FLG_CONSTTIME flag on before division operation */
817 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
820 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
824 if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;
826 /* If p < q it is occasionally possible for the correction of
827 * adding 'p' if r0 is negative above to leave the result still
828 * negative. This can break the private key operations: the following
829 * second correction should *always* correct this rare occurrence.
830 * This will *never* happen with OpenSSL generated keys because
831 * they ensure p > q [steve]
833 if (BN_is_negative(r0))
834 if (!BN_add(r0,r0,rsa->p)) goto err;
835 if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
836 if (!BN_add(r0,r1,m1)) goto err;
838 if (rsa->e && rsa->n)
840 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
841 /* If 'I' was greater than (or equal to) rsa->n, the operation
842 * will be equivalent to using 'I mod n'. However, the result of
843 * the verify will *always* be less than 'n' so we don't check
844 * for absolute equality, just congruency. */
845 if (!BN_sub(vrfy, vrfy, I)) goto err;
846 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
847 if (BN_is_negative(vrfy))
848 if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
849 if (!BN_is_zero(vrfy))
851 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
852 * miscalculated CRT output, just do a raw (slower)
853 * mod_exp and return that instead. */
858 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
861 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
865 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
866 rsa->_method_mod_n)) goto err;
875 static int RSA_eay_init(RSA *rsa)
877 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
881 static int RSA_eay_finish(RSA *rsa)
883 if (rsa->_method_mod_n != NULL)
884 BN_MONT_CTX_free(rsa->_method_mod_n);
885 if (rsa->_method_mod_p != NULL)
886 BN_MONT_CTX_free(rsa->_method_mod_p);
887 if (rsa->_method_mod_q != NULL)
888 BN_MONT_CTX_free(rsa->_method_mod_q);