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>
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);
155 * MONT_HELPER(rsa, bn_ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
157 #define MONT_HELPER(rsa, ctx, m, pre_cond, err_instr) \
158 if((pre_cond) && ((rsa)->_method_mod_##m == NULL) && \
159 !BN_MONT_CTX_set_locked(&((rsa)->_method_mod_##m), \
164 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
165 unsigned char *to, RSA *rsa, int padding)
168 int i,j,k,num=0,r= -1;
169 unsigned char *buf=NULL;
172 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
174 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
178 if (BN_ucmp(rsa->n, rsa->e) <= 0)
180 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
184 /* for large moduli, enforce exponent limit */
185 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
187 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
189 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
194 if ((ctx=BN_CTX_new()) == NULL) goto err;
197 ret = BN_CTX_get(ctx);
198 num=BN_num_bytes(rsa->n);
199 buf = OPENSSL_malloc(num);
200 if (!f || !ret || !buf)
202 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
208 case RSA_PKCS1_PADDING:
209 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
211 #ifndef OPENSSL_NO_SHA
212 case RSA_PKCS1_OAEP_PADDING:
213 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
216 case RSA_SSLV23_PADDING:
217 i=RSA_padding_add_SSLv23(buf,num,from,flen);
220 i=RSA_padding_add_none(buf,num,from,flen);
223 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
226 if (i <= 0) goto err;
228 if (BN_bin2bn(buf,num,f) == NULL) goto err;
230 if (BN_ucmp(f, rsa->n) >= 0)
232 /* usually the padding functions would catch this */
233 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
237 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
239 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
240 rsa->_method_mod_n)) goto err;
242 /* put in leading 0 bytes if the number is less than the
243 * length of the modulus */
245 i=BN_bn2bin(ret,&(to[num-j]));
246 for (k=0; k<(num-i); k++)
258 OPENSSL_cleanse(buf,num);
264 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
267 int got_write_lock = 0;
269 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
271 if (rsa->blinding == NULL)
273 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
274 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
277 if (rsa->blinding == NULL)
278 rsa->blinding = RSA_setup_blinding(rsa, ctx);
285 if (BN_BLINDING_get_thread_id(ret) == CRYPTO_thread_id())
287 /* rsa->blinding is ours! */
293 /* resort to rsa->mt_blinding instead */
295 *local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert()
296 * that the BN_BLINDING is shared, meaning that accesses
297 * require locks, and that the blinding factor must be
298 * stored outside the BN_BLINDING
301 if (rsa->mt_blinding == NULL)
305 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
306 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
310 if (rsa->mt_blinding == NULL)
311 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
313 ret = rsa->mt_blinding;
318 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
320 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
324 static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f,
325 BIGNUM *r, BN_CTX *ctx)
328 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
332 CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING);
333 ret = BN_BLINDING_convert_ex(f, r, b, ctx);
334 CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING);
339 static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f,
340 BIGNUM *r, BN_CTX *ctx)
343 return BN_BLINDING_invert_ex(f, NULL, b, ctx);
347 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
348 ret = BN_BLINDING_invert_ex(f, r, b, ctx);
349 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
355 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
356 unsigned char *to, RSA *rsa, int padding)
358 BIGNUM *f, *ret, *br, *res;
359 int i,j,k,num=0,r= -1;
360 unsigned char *buf=NULL;
362 int local_blinding = 0;
363 BN_BLINDING *blinding = NULL;
365 if ((ctx=BN_CTX_new()) == NULL) goto err;
368 br = BN_CTX_get(ctx);
369 ret = BN_CTX_get(ctx);
370 num = BN_num_bytes(rsa->n);
371 buf = OPENSSL_malloc(num);
372 if(!f || !ret || !buf)
374 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
380 case RSA_PKCS1_PADDING:
381 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
383 case RSA_X931_PADDING:
384 i=RSA_padding_add_X931(buf,num,from,flen);
387 i=RSA_padding_add_none(buf,num,from,flen);
389 case RSA_SSLV23_PADDING:
391 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
394 if (i <= 0) goto err;
396 if (BN_bin2bn(buf,num,f) == NULL) goto err;
398 if (BN_ucmp(f, rsa->n) >= 0)
400 /* usually the padding functions would catch this */
401 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
405 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
407 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
408 if (blinding == NULL)
410 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
415 if (blinding != NULL)
416 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
419 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
422 (rsa->dmp1 != NULL) &&
423 (rsa->dmq1 != NULL) &&
424 (rsa->iqmp != NULL)) )
426 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
433 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
437 BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
442 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
444 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
445 rsa->_method_mod_n)) goto err;
449 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
452 if (padding == RSA_X931_PADDING)
454 BN_sub(f, rsa->n, ret);
463 /* put in leading 0 bytes if the number is less than the
464 * length of the modulus */
466 i=BN_bn2bin(res,&(to[num-j]));
467 for (k=0; k<(num-i); k++)
479 OPENSSL_cleanse(buf,num);
485 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
486 unsigned char *to, RSA *rsa, int padding)
488 BIGNUM *f, *ret, *br;
491 unsigned char *buf=NULL;
493 int local_blinding = 0;
494 BN_BLINDING *blinding = NULL;
496 if((ctx = BN_CTX_new()) == NULL) goto err;
499 br = BN_CTX_get(ctx);
500 ret = BN_CTX_get(ctx);
501 num = BN_num_bytes(rsa->n);
502 buf = OPENSSL_malloc(num);
503 if(!f || !ret || !buf)
505 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
509 /* This check was for equality but PGP does evil things
510 * and chops off the top '0' bytes */
513 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
517 /* make data into a big number */
518 if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
520 if (BN_ucmp(f, rsa->n) >= 0)
522 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
526 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
528 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
529 if (blinding == NULL)
531 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
536 if (blinding != NULL)
537 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
541 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
544 (rsa->dmp1 != NULL) &&
545 (rsa->dmq1 != NULL) &&
546 (rsa->iqmp != NULL)) )
548 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
555 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
558 BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
563 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
564 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
570 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
574 j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
578 case RSA_PKCS1_PADDING:
579 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
581 #ifndef OPENSSL_NO_SHA
582 case RSA_PKCS1_OAEP_PADDING:
583 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
586 case RSA_SSLV23_PADDING:
587 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
590 r=RSA_padding_check_none(to,num,buf,j,num);
593 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
597 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
607 OPENSSL_cleanse(buf,num);
613 /* signature verification */
614 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
615 unsigned char *to, RSA *rsa, int padding)
620 unsigned char *buf=NULL;
623 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)
631 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
635 /* for large moduli, enforce exponent limit */
636 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
638 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
640 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
645 if((ctx = BN_CTX_new()) == NULL) goto err;
648 ret = BN_CTX_get(ctx);
649 num=BN_num_bytes(rsa->n);
650 buf = OPENSSL_malloc(num);
651 if(!f || !ret || !buf)
653 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
657 /* This check was for equality but PGP does evil things
658 * and chops off the top '0' bytes */
661 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
665 if (BN_bin2bn(from,flen,f) == NULL) goto err;
667 if (BN_ucmp(f, rsa->n) >= 0)
669 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
673 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
675 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
676 rsa->_method_mod_n)) goto err;
678 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
679 BN_sub(ret, rsa->n, ret);
686 case RSA_PKCS1_PADDING:
687 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
689 case RSA_X931_PADDING:
690 r=RSA_padding_check_X931(to,num,buf,i,num);
693 r=RSA_padding_check_none(to,num,buf,i,num);
696 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
700 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
710 OPENSSL_cleanse(buf,num);
716 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
718 BIGNUM *r1,*m1,*vrfy;
719 BIGNUM local_dmp1, local_dmq1;
724 r1 = BN_CTX_get(ctx);
725 m1 = BN_CTX_get(ctx);
726 vrfy = BN_CTX_get(ctx);
728 MONT_HELPER(rsa, ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
729 MONT_HELPER(rsa, ctx, q, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
730 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
732 if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
733 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
736 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_EXP_CONSTTIME);
740 if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
741 rsa->_method_mod_q)) goto err;
743 if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
744 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
747 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_EXP_CONSTTIME);
751 if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
752 rsa->_method_mod_p)) goto err;
754 if (!BN_sub(r0,r0,m1)) goto err;
755 /* This will help stop the size of r0 increasing, which does
756 * affect the multiply if it optimised for a power of 2 size */
757 if (BN_is_negative(r0))
758 if (!BN_add(r0,r0,rsa->p)) goto err;
760 if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
761 if (!BN_mod(r0,r1,rsa->p,ctx)) goto err;
762 /* If p < q it is occasionally possible for the correction of
763 * adding 'p' if r0 is negative above to leave the result still
764 * negative. This can break the private key operations: the following
765 * second correction should *always* correct this rare occurrence.
766 * This will *never* happen with OpenSSL generated keys because
767 * they ensure p > q [steve]
769 if (BN_is_negative(r0))
770 if (!BN_add(r0,r0,rsa->p)) goto err;
771 if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
772 if (!BN_add(r0,r1,m1)) goto err;
774 if (rsa->e && rsa->n)
776 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
777 /* If 'I' was greater than (or equal to) rsa->n, the operation
778 * will be equivalent to using 'I mod n'. However, the result of
779 * the verify will *always* be less than 'n' so we don't check
780 * for absolute equality, just congruency. */
781 if (!BN_sub(vrfy, vrfy, I)) goto err;
782 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
783 if (BN_is_negative(vrfy))
784 if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
785 if (!BN_is_zero(vrfy))
787 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
788 * miscalculated CRT output, just do a raw (slower)
789 * mod_exp and return that instead. */
794 if (!(rsa->flags & RSA_FLAG_NO_EXP_CONSTTIME))
797 BN_with_flags(d, rsa->d, BN_FLG_EXP_CONSTTIME);
801 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
802 rsa->_method_mod_n)) goto err;
811 static int RSA_eay_init(RSA *rsa)
813 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
817 static int RSA_eay_finish(RSA *rsa)
819 if (rsa->_method_mod_n != NULL)
820 BN_MONT_CTX_free(rsa->_method_mod_n);
821 if (rsa->_method_mod_p != NULL)
822 BN_MONT_CTX_free(rsa->_method_mod_p);
823 if (rsa->_method_mod_q != NULL)
824 BN_MONT_CTX_free(rsa->_method_mod_q);