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);
153 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
154 unsigned char *to, RSA *rsa, int padding)
157 int i,j,k,num=0,r= -1;
158 unsigned char *buf=NULL;
161 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)
169 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
173 /* for large moduli, enforce exponent limit */
174 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
176 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
178 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
183 if ((ctx=BN_CTX_new()) == NULL) goto err;
186 ret = BN_CTX_get(ctx);
187 num=BN_num_bytes(rsa->n);
188 buf = OPENSSL_malloc(num);
189 if (!f || !ret || !buf)
191 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
197 case RSA_PKCS1_PADDING:
198 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
200 #ifndef OPENSSL_NO_SHA
201 case RSA_PKCS1_OAEP_PADDING:
202 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
205 case RSA_SSLV23_PADDING:
206 i=RSA_padding_add_SSLv23(buf,num,from,flen);
209 i=RSA_padding_add_none(buf,num,from,flen);
212 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
215 if (i <= 0) goto err;
217 if (BN_bin2bn(buf,num,f) == NULL) goto err;
219 if (BN_ucmp(f, rsa->n) >= 0)
221 /* usually the padding functions would catch this */
222 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
226 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
227 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, 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 */
236 i=BN_bn2bin(ret,&(to[num-j]));
237 for (k=0; k<(num-i); k++)
249 OPENSSL_cleanse(buf,num);
255 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
258 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 CRYPTO_THREADID_current(&cur);
278 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret)))
280 /* rsa->blinding is ours! */
286 /* resort to rsa->mt_blinding instead */
288 /* instructs rsa_blinding_convert(), rsa_blinding_invert()
289 * that the BN_BLINDING is shared, meaning that accesses
290 * require locks, and that the blinding factor must be
291 * stored outside the BN_BLINDING
295 if (rsa->mt_blinding == NULL)
299 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
300 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
304 if (rsa->mt_blinding == NULL)
305 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
307 ret = rsa->mt_blinding;
312 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
314 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
318 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
322 /* Local blinding: store the unblinding factor
324 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
327 /* Shared blinding: store the unblinding factor
328 * outside BN_BLINDING. */
330 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
331 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
332 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
337 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
340 /* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
341 * will use the unblinding factor stored in BN_BLINDING.
342 * If BN_BLINDING is shared between threads, unblind must be non-null:
343 * BN_BLINDING_invert_ex will then use the local unblinding factor,
344 * and will only read the modulus from BN_BLINDING.
345 * In both cases it's safe to access the blinding without a lock.
347 return BN_BLINDING_invert_ex(f, unblind, b, ctx);
351 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
352 unsigned char *to, RSA *rsa, int padding)
354 BIGNUM *f, *ret, *res;
355 int i,j,k,num=0,r= -1;
356 unsigned char *buf=NULL;
358 int local_blinding = 0;
359 /* Used only if the blinding structure is shared. A non-NULL unblind
360 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
361 * the unblinding factor outside the blinding structure. */
362 BIGNUM *unblind = NULL;
363 BN_BLINDING *blinding = NULL;
365 if ((ctx=BN_CTX_new()) == NULL) goto err;
368 ret = BN_CTX_get(ctx);
369 num = BN_num_bytes(rsa->n);
370 buf = OPENSSL_malloc(num);
371 if(!f || !ret || !buf)
373 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
379 case RSA_PKCS1_PADDING:
380 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
382 case RSA_X931_PADDING:
383 i=RSA_padding_add_X931(buf,num,from,flen);
386 i=RSA_padding_add_none(buf,num,from,flen);
388 case RSA_SSLV23_PADDING:
390 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
393 if (i <= 0) goto err;
395 if (BN_bin2bn(buf,num,f) == NULL) goto err;
397 if (BN_ucmp(f, rsa->n) >= 0)
399 /* usually the padding functions would catch this */
400 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
404 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
406 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
407 if (blinding == NULL)
409 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
414 if (blinding != NULL)
416 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL))
418 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
421 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
425 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
428 (rsa->dmp1 != NULL) &&
429 (rsa->dmq1 != NULL) &&
430 (rsa->iqmp != NULL)) )
432 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
439 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
443 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
448 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
449 if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
452 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
453 rsa->_method_mod_n)) goto err;
457 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
460 if (padding == RSA_X931_PADDING)
462 BN_sub(f, rsa->n, ret);
463 if (BN_cmp(ret, f) > 0)
471 /* put in leading 0 bytes if the number is less than the
472 * length of the modulus */
474 i=BN_bn2bin(res,&(to[num-j]));
475 for (k=0; k<(num-i); k++)
487 OPENSSL_cleanse(buf,num);
493 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
494 unsigned char *to, RSA *rsa, int padding)
499 unsigned char *buf=NULL;
501 int local_blinding = 0;
502 /* Used only if the blinding structure is shared. A non-NULL unblind
503 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
504 * the unblinding factor outside the blinding structure. */
505 BIGNUM *unblind = NULL;
506 BN_BLINDING *blinding = NULL;
508 if((ctx = BN_CTX_new()) == NULL) goto err;
511 ret = BN_CTX_get(ctx);
512 num = BN_num_bytes(rsa->n);
513 buf = OPENSSL_malloc(num);
514 if(!f || !ret || !buf)
516 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
520 /* This check was for equality but PGP does evil things
521 * and chops off the top '0' bytes */
524 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
528 /* make data into a big number */
529 if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
531 if (BN_ucmp(f, rsa->n) >= 0)
533 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
537 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
539 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
540 if (blinding == NULL)
542 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
547 if (blinding != NULL)
549 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL))
551 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
554 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
559 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
562 (rsa->dmp1 != NULL) &&
563 (rsa->dmq1 != NULL) &&
564 (rsa->iqmp != NULL)) )
566 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
573 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
576 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
581 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
582 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
584 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
590 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
594 j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
598 case RSA_PKCS1_PADDING:
599 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
601 #ifndef OPENSSL_NO_SHA
602 case RSA_PKCS1_OAEP_PADDING:
603 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
606 case RSA_SSLV23_PADDING:
607 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
610 r=RSA_padding_check_none(to,num,buf,j,num);
613 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
617 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
627 OPENSSL_cleanse(buf,num);
633 /* signature verification */
634 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
635 unsigned char *to, RSA *rsa, int padding)
640 unsigned char *buf=NULL;
643 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
645 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
649 if (BN_ucmp(rsa->n, rsa->e) <= 0)
651 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
655 /* for large moduli, enforce exponent limit */
656 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
658 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
660 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
665 if((ctx = BN_CTX_new()) == NULL) goto err;
668 ret = BN_CTX_get(ctx);
669 num=BN_num_bytes(rsa->n);
670 buf = OPENSSL_malloc(num);
671 if(!f || !ret || !buf)
673 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
677 /* This check was for equality but PGP does evil things
678 * and chops off the top '0' bytes */
681 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
685 if (BN_bin2bn(from,flen,f) == NULL) goto err;
687 if (BN_ucmp(f, rsa->n) >= 0)
689 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
693 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
694 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
697 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
698 rsa->_method_mod_n)) goto err;
700 if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
701 if (!BN_sub(ret, rsa->n, ret)) goto err;
708 case RSA_PKCS1_PADDING:
709 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
711 case RSA_X931_PADDING:
712 r=RSA_padding_check_X931(to,num,buf,i,num);
715 r=RSA_padding_check_none(to,num,buf,i,num);
718 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
722 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
732 OPENSSL_cleanse(buf,num);
738 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
740 BIGNUM *r1,*m1,*vrfy;
741 BIGNUM local_dmp1,local_dmq1,local_c,local_r1;
742 BIGNUM *dmp1,*dmq1,*c,*pr1;
746 r1 = BN_CTX_get(ctx);
747 m1 = BN_CTX_get(ctx);
748 vrfy = BN_CTX_get(ctx);
751 BIGNUM local_p, local_q;
752 BIGNUM *p = NULL, *q = NULL;
754 /* Make sure BN_mod_inverse in Montgomery intialization uses the
755 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
757 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
761 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
765 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
773 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
775 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx))
777 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
782 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
783 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
786 /* compute I mod q */
787 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
790 BN_with_flags(c, I, BN_FLG_CONSTTIME);
791 if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
795 if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
798 /* compute r1^dmq1 mod q */
799 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
802 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
806 if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
807 rsa->_method_mod_q)) goto err;
809 /* compute I mod p */
810 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
813 BN_with_flags(c, I, BN_FLG_CONSTTIME);
814 if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
818 if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
821 /* compute r1^dmp1 mod p */
822 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
825 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
829 if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
830 rsa->_method_mod_p)) goto err;
832 if (!BN_sub(r0,r0,m1)) goto err;
833 /* This will help stop the size of r0 increasing, which does
834 * affect the multiply if it optimised for a power of 2 size */
835 if (BN_is_negative(r0))
836 if (!BN_add(r0,r0,rsa->p)) goto err;
838 if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
840 /* Turn BN_FLG_CONSTTIME flag on before division operation */
841 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
844 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
848 if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;
850 /* If p < q it is occasionally possible for the correction of
851 * adding 'p' if r0 is negative above to leave the result still
852 * negative. This can break the private key operations: the following
853 * second correction should *always* correct this rare occurrence.
854 * This will *never* happen with OpenSSL generated keys because
855 * they ensure p > q [steve]
857 if (BN_is_negative(r0))
858 if (!BN_add(r0,r0,rsa->p)) goto err;
859 if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
860 if (!BN_add(r0,r1,m1)) goto err;
862 if (rsa->e && rsa->n)
864 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
865 /* If 'I' was greater than (or equal to) rsa->n, the operation
866 * will be equivalent to using 'I mod n'. However, the result of
867 * the verify will *always* be less than 'n' so we don't check
868 * for absolute equality, just congruency. */
869 if (!BN_sub(vrfy, vrfy, I)) goto err;
870 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
871 if (BN_is_negative(vrfy))
872 if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
873 if (!BN_is_zero(vrfy))
875 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
876 * miscalculated CRT output, just do a raw (slower)
877 * mod_exp and return that instead. */
882 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
885 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
889 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
890 rsa->_method_mod_n)) goto err;
899 static int RSA_eay_init(RSA *rsa)
901 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
905 static int RSA_eay_finish(RSA *rsa)
907 if (rsa->_method_mod_n != NULL)
908 BN_MONT_CTX_free(rsa->_method_mod_n);
909 if (rsa->_method_mod_p != NULL)
910 BN_MONT_CTX_free(rsa->_method_mod_p);
911 if (rsa->_method_mod_q != NULL)
912 BN_MONT_CTX_free(rsa->_method_mod_q);