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>
118 #if !defined(RSA_NULL) && !defined(OPENSSL_FIPS)
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);
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 if e == 3 */
147 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
149 return(&rsa_pkcs1_eay_meth);
152 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
153 unsigned char *to, RSA *rsa, int padding)
156 int i,j,k,num=0,r= -1;
157 unsigned char *buf=NULL;
160 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
162 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
166 if (BN_ucmp(rsa->n, rsa->e) <= 0)
168 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
172 /* for large moduli, enforce exponent limit */
173 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
175 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
177 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
184 if ((ctx=BN_CTX_new()) == NULL) goto err;
185 num=BN_num_bytes(rsa->n);
186 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
188 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);
212 if (i <= 0) goto err;
214 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
216 if (BN_ucmp(&f, rsa->n) >= 0)
218 /* usually the padding functions would catch this */
219 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
223 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
225 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
226 CRYPTO_LOCK_RSA, rsa->n, ctx))
230 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
231 rsa->_method_mod_n)) goto err;
233 /* put in leading 0 bytes if the number is less than the
234 * length of the modulus */
235 j=BN_num_bytes(&ret);
236 i=BN_bn2bin(&ret,&(to[num-j]));
237 for (k=0; k<(num-i); k++)
242 if (ctx != NULL) BN_CTX_free(ctx);
247 OPENSSL_cleanse(buf,num);
253 static int blinding_helper(RSA *rsa, BN_CTX *ctx)
256 int got_write_lock = 0;
258 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
260 if (rsa->flags & RSA_FLAG_NO_BLINDING)
264 if (rsa->blinding != NULL)
268 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
269 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
272 if(rsa->blinding != NULL)
275 ret = RSA_blinding_on(rsa, ctx);
280 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
282 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
287 static BN_BLINDING *setup_blinding(RSA *rsa, BN_CTX *ctx)
290 BN_BLINDING *ret = NULL;
292 /* added in OpenSSL 0.9.6j and 0.9.7b */
294 /* NB: similar code appears in RSA_blinding_on (rsa_lib.c);
295 * this should be placed in a new function of its own, but for reasons
296 * of binary compatibility can't */
300 if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
302 /* if PRNG is not properly seeded, resort to secret exponent as unpredictable seed */
303 RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0);
304 if (!BN_pseudo_rand_range(A,rsa->n)) goto err;
308 if (!BN_rand_range(A,rsa->n)) goto err;
310 if ((Ai=BN_mod_inverse(NULL,A,rsa->n,ctx)) == NULL) goto err;
312 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
314 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
315 CRYPTO_LOCK_RSA, rsa->n, ctx))
319 if (!rsa->meth->bn_mod_exp(A,A,rsa->e,rsa->n,ctx,rsa->_method_mod_n))
321 ret = BN_BLINDING_new(A,Ai,rsa->n);
329 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
330 unsigned char *to, RSA *rsa, int padding)
333 int i,j,k,num=0,r= -1;
334 unsigned char *buf=NULL;
336 int local_blinding = 0;
337 BN_BLINDING *blinding = NULL;
342 if ((ctx=BN_CTX_new()) == NULL) goto err;
343 num=BN_num_bytes(rsa->n);
344 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
346 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
352 case RSA_PKCS1_PADDING:
353 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
356 i=RSA_padding_add_none(buf,num,from,flen);
358 case RSA_SSLV23_PADDING:
360 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
363 if (i <= 0) goto err;
365 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
367 if (BN_ucmp(&f, rsa->n) >= 0)
369 /* usually the padding functions would catch this */
370 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
374 if (!blinding_helper(rsa, ctx))
376 blinding = rsa->blinding;
378 /* Now unless blinding is disabled, 'blinding' is non-NULL.
379 * But the BN_BLINDING object may be owned by some other thread
380 * (we don't want to keep it constant and we don't want to use
381 * lots of locking to avoid race conditions, so only a single
382 * thread can use it; other threads have to use local blinding
384 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
386 if (blinding == NULL)
388 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
393 if (blinding != NULL)
397 /* we need a local one-time blinding factor */
399 blinding = setup_blinding(rsa, ctx);
400 if (blinding == NULL)
407 if (!BN_BLINDING_convert(&f, blinding, ctx)) goto err;
409 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
412 (rsa->dmp1 != NULL) &&
413 (rsa->dmq1 != NULL) &&
414 (rsa->iqmp != NULL)) )
416 if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err;
423 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
427 BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
431 if (!rsa->meth->bn_mod_exp(&ret,&f,d,rsa->n,ctx,NULL)) goto err;
435 if (!BN_BLINDING_invert(&ret, blinding, ctx)) goto err;
437 if (padding == RSA_X931_PADDING)
439 BN_sub(&f, rsa->n, &ret);
440 if (BN_cmp(&ret, &f))
448 /* put in leading 0 bytes if the number is less than the
449 * length of the modulus */
451 i=BN_bn2bin(res,&(to[num-j]));
452 for (k=0; k<(num-i); k++)
457 if (ctx != NULL) BN_CTX_free(ctx);
461 BN_BLINDING_free(blinding);
464 OPENSSL_cleanse(buf,num);
470 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
471 unsigned char *to, RSA *rsa, int padding)
476 unsigned char *buf=NULL;
478 int local_blinding = 0;
479 BN_BLINDING *blinding = NULL;
484 if (ctx == NULL) goto err;
486 num=BN_num_bytes(rsa->n);
488 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
490 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
494 /* This check was for equality but PGP does evil things
495 * and chops off the top '0' bytes */
498 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
502 /* make data into a big number */
503 if (BN_bin2bn(from,(int)flen,&f) == NULL) goto err;
505 if (BN_ucmp(&f, rsa->n) >= 0)
507 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
511 if (!blinding_helper(rsa, ctx))
513 blinding = rsa->blinding;
515 /* Now unless blinding is disabled, 'blinding' is non-NULL.
516 * But the BN_BLINDING object may be owned by some other thread
517 * (we don't want to keep it constant and we don't want to use
518 * lots of locking to avoid race conditions, so only a single
519 * thread can use it; other threads have to use local blinding
521 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
523 if (blinding == NULL)
525 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
530 if (blinding != NULL)
534 /* we need a local one-time blinding factor */
536 blinding = setup_blinding(rsa, ctx);
537 if (blinding == NULL)
544 if (!BN_BLINDING_convert(&f, blinding, ctx)) goto err;
547 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
550 (rsa->dmp1 != NULL) &&
551 (rsa->dmq1 != NULL) &&
552 (rsa->iqmp != NULL)) )
554 if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err;
561 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
564 BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
568 if (!rsa->meth->bn_mod_exp(&ret,&f,d,rsa->n,ctx,NULL))
573 if (!BN_BLINDING_invert(&ret, blinding, ctx)) goto err;
576 j=BN_bn2bin(&ret,p); /* j is only used with no-padding mode */
580 case RSA_PKCS1_PADDING:
581 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
583 #ifndef OPENSSL_NO_SHA
584 case RSA_PKCS1_OAEP_PADDING:
585 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
588 case RSA_SSLV23_PADDING:
589 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
592 r=RSA_padding_check_none(to,num,buf,j,num);
595 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
599 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
602 if (ctx != NULL) BN_CTX_free(ctx);
606 BN_BLINDING_free(blinding);
609 OPENSSL_cleanse(buf,num);
615 /* signature verification */
616 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
617 unsigned char *to, RSA *rsa, int padding)
622 unsigned char *buf=NULL;
625 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
627 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
631 if (BN_ucmp(rsa->n, rsa->e) <= 0)
633 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
637 /* for large moduli, enforce exponent limit */
638 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
640 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
642 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
650 if (ctx == NULL) goto err;
652 num=BN_num_bytes(rsa->n);
653 buf=(unsigned char *)OPENSSL_malloc(num);
656 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
660 /* This check was for equality but PGP does evil things
661 * and chops off the top '0' bytes */
664 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
668 if (BN_bin2bn(from,flen,&f) == NULL) goto err;
670 if (BN_ucmp(&f, rsa->n) >= 0)
672 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
678 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
680 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
681 CRYPTO_LOCK_RSA, rsa->n, ctx))
685 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
686 rsa->_method_mod_n)) goto err;
688 if ((padding == RSA_X931_PADDING) && ((ret.d[0] & 0xf) != 12))
689 BN_sub(&ret, rsa->n, &ret);
696 case RSA_PKCS1_PADDING:
697 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
700 r=RSA_padding_check_none(to,num,buf,i,num);
703 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
707 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
710 if (ctx != NULL) BN_CTX_free(ctx);
715 OPENSSL_cleanse(buf,num);
721 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
724 BIGNUM local_dmp1, local_dmq1;
732 if ((ctx=BN_CTX_new()) == NULL) goto err;
734 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
736 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p,
737 CRYPTO_LOCK_RSA, rsa->p, ctx))
739 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
740 CRYPTO_LOCK_RSA, rsa->q, ctx))
744 if (!BN_mod(&r1,I,rsa->q,ctx)) goto err;
745 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
748 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_EXP_CONSTTIME);
752 if (!rsa->meth->bn_mod_exp(&m1,&r1,dmq1,rsa->q,ctx,
753 rsa->_method_mod_q)) goto err;
755 if (!BN_mod(&r1,I,rsa->p,ctx)) goto err;
756 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
759 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_EXP_CONSTTIME);
763 if (!rsa->meth->bn_mod_exp(r0,&r1,dmp1,rsa->p,ctx,
764 rsa->_method_mod_p)) goto err;
766 if (!BN_sub(r0,r0,&m1)) goto err;
767 /* This will help stop the size of r0 increasing, which does
768 * affect the multiply if it optimised for a power of 2 size */
770 if (!BN_add(r0,r0,rsa->p)) goto err;
772 if (!BN_mul(&r1,r0,rsa->iqmp,ctx)) goto err;
773 if (!BN_mod(r0,&r1,rsa->p,ctx)) goto err;
774 /* If p < q it is occasionally possible for the correction of
775 * adding 'p' if r0 is negative above to leave the result still
776 * negative. This can break the private key operations: the following
777 * second correction should *always* correct this rare occurrence.
778 * This will *never* happen with OpenSSL generated keys because
779 * they ensure p > q [steve]
782 if (!BN_add(r0,r0,rsa->p)) goto err;
783 if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;
784 if (!BN_add(r0,&r1,&m1)) goto err;
786 if (rsa->e && rsa->n)
788 if (!rsa->meth->bn_mod_exp(&vrfy,r0,rsa->e,rsa->n,ctx,NULL)) goto err;
789 /* If 'I' was greater than (or equal to) rsa->n, the operation
790 * will be equivalent to using 'I mod n'. However, the result of
791 * the verify will *always* be less than 'n' so we don't check
792 * for absolute equality, just congruency. */
793 if (!BN_sub(&vrfy, &vrfy, I)) goto err;
794 if (!BN_mod(&vrfy, &vrfy, rsa->n, ctx)) goto err;
796 if (!BN_add(&vrfy, &vrfy, rsa->n)) goto err;
797 if (!BN_is_zero(&vrfy))
799 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
800 * miscalculated CRT output, just do a raw (slower)
801 * mod_exp and return that instead. */
806 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
809 BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
813 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,NULL)) goto err;
820 BN_clear_free(&vrfy);
825 static int RSA_eay_init(RSA *rsa)
827 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
831 static int RSA_eay_finish(RSA *rsa)
833 if (rsa->_method_mod_n != NULL)
834 BN_MONT_CTX_free(rsa->_method_mod_n);
835 if (rsa->_method_mod_p != NULL)
836 BN_MONT_CTX_free(rsa->_method_mod_p);
837 if (rsa->_method_mod_q != NULL)
838 BN_MONT_CTX_free(rsa->_method_mod_q);