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>
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, BN_CTX *ctx);
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 */
145 NULL /* rsa_keygen */
148 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
150 return(&rsa_pkcs1_eay_meth);
154 * MONT_HELPER(rsa->_method_mod_p, bn_ctx, rsa->p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
156 #define MONT_HELPER(method_mod, ctx, m, pre_cond, err_instr) \
157 if ((pre_cond) && ((method_mod) == NULL) && \
158 !BN_MONT_CTX_set_locked(&(method_mod), \
163 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
164 unsigned char *to, RSA *rsa, int padding)
167 int i,j,k,num=0,r= -1;
168 unsigned char *buf=NULL;
171 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
173 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
177 if (BN_ucmp(rsa->n, rsa->e) <= 0)
179 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
183 /* for large moduli, enforce exponent limit */
184 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
186 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
188 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
193 if ((ctx=BN_CTX_new()) == NULL) goto err;
196 ret = BN_CTX_get(ctx);
197 num=BN_num_bytes(rsa->n);
198 buf = OPENSSL_malloc(num);
199 if (!f || !ret || !buf)
201 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
207 case RSA_PKCS1_PADDING:
208 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
210 #ifndef OPENSSL_NO_SHA
211 case RSA_PKCS1_OAEP_PADDING:
212 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
215 case RSA_SSLV23_PADDING:
216 i=RSA_padding_add_SSLv23(buf,num,from,flen);
219 i=RSA_padding_add_none(buf,num,from,flen);
222 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
225 if (i <= 0) goto err;
227 if (BN_bin2bn(buf,num,f) == NULL) goto err;
229 if (BN_ucmp(f, rsa->n) >= 0)
231 /* usually the padding functions would catch this */
232 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
236 MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
238 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
239 rsa->_method_mod_n)) goto err;
241 /* put in leading 0 bytes if the number is less than the
242 * length of the modulus */
244 i=BN_bn2bin(ret,&(to[num-j]));
245 for (k=0; k<(num-i); k++)
257 OPENSSL_cleanse(buf,num);
263 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
267 int got_write_lock = 0;
269 CRYPTO_THREADID_set(&tid);
270 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
272 if (rsa->blinding == NULL)
274 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
275 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
278 if (rsa->blinding == NULL)
279 rsa->blinding = RSA_setup_blinding(rsa, ctx);
286 if (!BN_BLINDING_cmp_thread(ret, &tid))
288 /* rsa->blinding is ours! */
294 /* resort to rsa->mt_blinding instead */
296 *local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert()
297 * that the BN_BLINDING is shared, meaning that accesses
298 * require locks, and that the blinding factor must be
299 * stored outside the BN_BLINDING
302 if (rsa->mt_blinding == NULL)
306 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
307 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
311 if (rsa->mt_blinding == NULL)
312 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
314 ret = rsa->mt_blinding;
319 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
321 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
325 static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f,
326 BIGNUM *r, BN_CTX *ctx)
329 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
333 CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING);
334 ret = BN_BLINDING_convert_ex(f, r, b, ctx);
335 CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING);
340 static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f,
341 BIGNUM *r, BN_CTX *ctx)
344 return BN_BLINDING_invert_ex(f, NULL, b, ctx);
348 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
349 ret = BN_BLINDING_invert_ex(f, r, b, ctx);
350 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
356 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
357 unsigned char *to, RSA *rsa, int padding)
359 BIGNUM *f, *ret, *br, *res;
360 int i,j,k,num=0,r= -1;
361 unsigned char *buf=NULL;
363 int local_blinding = 0;
364 BN_BLINDING *blinding = NULL;
366 if ((ctx=BN_CTX_new()) == NULL) goto err;
369 br = BN_CTX_get(ctx);
370 ret = BN_CTX_get(ctx);
371 num = BN_num_bytes(rsa->n);
372 buf = OPENSSL_malloc(num);
373 if(!f || !ret || !buf)
375 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
381 case RSA_PKCS1_PADDING:
382 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
384 case RSA_X931_PADDING:
385 i=RSA_padding_add_X931(buf,num,from,flen);
388 i=RSA_padding_add_none(buf,num,from,flen);
390 case RSA_SSLV23_PADDING:
392 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
395 if (i <= 0) goto err;
397 if (BN_bin2bn(buf,num,f) == NULL) goto err;
399 if (BN_ucmp(f, rsa->n) >= 0)
401 /* usually the padding functions would catch this */
402 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
406 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
408 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
409 if (blinding == NULL)
411 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
416 if (blinding != NULL)
417 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
420 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
423 (rsa->dmp1 != NULL) &&
424 (rsa->dmq1 != NULL) &&
425 (rsa->iqmp != NULL)) )
427 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
434 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
438 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
443 MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
445 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
446 rsa->_method_mod_n)) goto err;
450 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
453 if (padding == RSA_X931_PADDING)
455 BN_sub(f, rsa->n, ret);
464 /* put in leading 0 bytes if the number is less than the
465 * length of the modulus */
467 i=BN_bn2bin(res,&(to[num-j]));
468 for (k=0; k<(num-i); k++)
480 OPENSSL_cleanse(buf,num);
486 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
487 unsigned char *to, RSA *rsa, int padding)
489 BIGNUM *f, *ret, *br;
492 unsigned char *buf=NULL;
494 int local_blinding = 0;
495 BN_BLINDING *blinding = NULL;
497 if((ctx = BN_CTX_new()) == NULL) goto err;
500 br = BN_CTX_get(ctx);
501 ret = BN_CTX_get(ctx);
502 num = BN_num_bytes(rsa->n);
503 buf = OPENSSL_malloc(num);
504 if(!f || !ret || !buf)
506 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
510 /* This check was for equality but PGP does evil things
511 * and chops off the top '0' bytes */
514 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
518 /* make data into a big number */
519 if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
521 if (BN_ucmp(f, rsa->n) >= 0)
523 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
527 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
529 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
530 if (blinding == NULL)
532 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
537 if (blinding != NULL)
538 if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
542 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
545 (rsa->dmp1 != NULL) &&
546 (rsa->dmq1 != NULL) &&
547 (rsa->iqmp != NULL)) )
549 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
556 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
559 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
564 MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
565 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
571 if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
575 j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
579 case RSA_PKCS1_PADDING:
580 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
582 #ifndef OPENSSL_NO_SHA
583 case RSA_PKCS1_OAEP_PADDING:
584 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
587 case RSA_SSLV23_PADDING:
588 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
591 r=RSA_padding_check_none(to,num,buf,j,num);
594 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
598 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
608 OPENSSL_cleanse(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)
621 unsigned char *buf=NULL;
624 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
626 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
630 if (BN_ucmp(rsa->n, rsa->e) <= 0)
632 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
636 /* for large moduli, enforce exponent limit */
637 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
639 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
641 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
646 if((ctx = BN_CTX_new()) == NULL) goto err;
649 ret = BN_CTX_get(ctx);
650 num=BN_num_bytes(rsa->n);
651 buf = OPENSSL_malloc(num);
652 if(!f || !ret || !buf)
654 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
658 /* This check was for equality but PGP does evil things
659 * and chops off the top '0' bytes */
662 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
666 if (BN_bin2bn(from,flen,f) == NULL) goto err;
668 if (BN_ucmp(f, rsa->n) >= 0)
670 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
674 MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
676 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
677 rsa->_method_mod_n)) goto err;
679 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
680 BN_sub(ret, rsa->n, ret);
687 case RSA_PKCS1_PADDING:
688 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
690 case RSA_X931_PADDING:
691 r=RSA_padding_check_X931(to,num,buf,i,num);
694 r=RSA_padding_check_none(to,num,buf,i,num);
697 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
701 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
711 OPENSSL_cleanse(buf,num);
717 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
719 BIGNUM *r1,*m1,*vrfy;
720 BIGNUM local_dmp1,local_dmq1,local_c,local_r1;
721 BIGNUM *dmp1,*dmq1,*c,*pr1;
725 r1 = BN_CTX_get(ctx);
726 m1 = BN_CTX_get(ctx);
727 vrfy = BN_CTX_get(ctx);
730 BIGNUM local_p, local_q;
731 BIGNUM *p = NULL, *q = NULL;
733 /* Make sure BN_mod_inverse in Montgomery intialization uses the
734 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
736 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
740 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
744 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
752 MONT_HELPER(rsa->_method_mod_p, ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
753 MONT_HELPER(rsa->_method_mod_q, ctx, q, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
756 MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
758 /* compute I mod q */
759 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
762 BN_with_flags(c, I, BN_FLG_CONSTTIME);
763 if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
767 if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
770 /* compute r1^dmq1 mod q */
771 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
774 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
778 if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
779 rsa->_method_mod_q)) goto err;
781 /* compute I mod p */
782 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
785 BN_with_flags(c, I, BN_FLG_CONSTTIME);
786 if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
790 if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
793 /* compute r1^dmp1 mod p */
794 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
797 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
801 if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
802 rsa->_method_mod_p)) goto err;
804 if (!BN_sub(r0,r0,m1)) goto err;
805 /* This will help stop the size of r0 increasing, which does
806 * affect the multiply if it optimised for a power of 2 size */
807 if (BN_is_negative(r0))
808 if (!BN_add(r0,r0,rsa->p)) goto err;
810 if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
812 /* Turn BN_FLG_CONSTTIME flag on before division operation */
813 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
816 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
820 if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;
822 /* If p < q it is occasionally possible for the correction of
823 * adding 'p' if r0 is negative above to leave the result still
824 * negative. This can break the private key operations: the following
825 * second correction should *always* correct this rare occurrence.
826 * This will *never* happen with OpenSSL generated keys because
827 * they ensure p > q [steve]
829 if (BN_is_negative(r0))
830 if (!BN_add(r0,r0,rsa->p)) goto err;
831 if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
832 if (!BN_add(r0,r1,m1)) goto err;
834 if (rsa->e && rsa->n)
836 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
837 /* If 'I' was greater than (or equal to) rsa->n, the operation
838 * will be equivalent to using 'I mod n'. However, the result of
839 * the verify will *always* be less than 'n' so we don't check
840 * for absolute equality, just congruency. */
841 if (!BN_sub(vrfy, vrfy, I)) goto err;
842 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
843 if (BN_is_negative(vrfy))
844 if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
845 if (!BN_is_zero(vrfy))
847 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
848 * miscalculated CRT output, just do a raw (slower)
849 * mod_exp and return that instead. */
854 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
857 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
861 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
862 rsa->_method_mod_n)) goto err;
871 static int RSA_eay_init(RSA *rsa)
873 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
877 static int RSA_eay_finish(RSA *rsa)
879 if (rsa->_method_mod_n != NULL)
880 BN_MONT_CTX_free(rsa->_method_mod_n);
881 if (rsa->_method_mod_p != NULL)
882 BN_MONT_CTX_free(rsa->_method_mod_p);
883 if (rsa->_method_mod_q != NULL)
884 BN_MONT_CTX_free(rsa->_method_mod_q);