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 "internal/bn_int.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 */
142 RSA_FLAG_FIPS_METHOD, /* flags */
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;
262 CRYPTO_r_lock(CRYPTO_LOCK_RSA);
264 if (rsa->blinding == NULL)
266 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
267 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
270 if (rsa->blinding == NULL)
271 rsa->blinding = RSA_setup_blinding(rsa, ctx);
278 CRYPTO_THREADID_current(&cur);
279 if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret)))
281 /* rsa->blinding is ours! */
287 /* resort to rsa->mt_blinding instead */
289 /* instructs rsa_blinding_convert(), rsa_blinding_invert()
290 * that the BN_BLINDING is shared, meaning that accesses
291 * require locks, and that the blinding factor must be
292 * stored outside the BN_BLINDING
296 if (rsa->mt_blinding == NULL)
300 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
301 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
305 if (rsa->mt_blinding == NULL)
306 rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
308 ret = rsa->mt_blinding;
313 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
315 CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
319 static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
323 /* Local blinding: store the unblinding factor
325 return BN_BLINDING_convert_ex(f, NULL, b, ctx);
328 /* Shared blinding: store the unblinding factor
329 * outside BN_BLINDING. */
331 CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
332 ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
333 CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
338 static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
341 /* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
342 * will use the unblinding factor stored in BN_BLINDING.
343 * If BN_BLINDING is shared between threads, unblind must be non-null:
344 * BN_BLINDING_invert_ex will then use the local unblinding factor,
345 * and will only read the modulus from BN_BLINDING.
346 * In both cases it's safe to access the blinding without a lock.
348 return BN_BLINDING_invert_ex(f, unblind, b, ctx);
352 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
353 unsigned char *to, RSA *rsa, int padding)
355 BIGNUM *f, *ret, *res;
356 int i,j,k,num=0,r= -1;
357 unsigned char *buf=NULL;
359 int local_blinding = 0;
360 /* Used only if the blinding structure is shared. A non-NULL unblind
361 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
362 * the unblinding factor outside the blinding structure. */
363 BIGNUM *unblind = NULL;
364 BN_BLINDING *blinding = NULL;
366 if ((ctx=BN_CTX_new()) == NULL) goto err;
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)
417 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL))
419 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
422 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
426 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
429 (rsa->dmp1 != NULL) &&
430 (rsa->dmq1 != NULL) &&
431 (rsa->iqmp != NULL)) )
433 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
437 BIGNUM *d = NULL, *local_d = NULL;
439 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
441 local_d = d = BN_new();
444 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
447 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
452 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
453 if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
455 if(local_d) BN_free(local_d);
459 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
462 if(local_d) BN_free(local_d);
465 if(local_d) BN_free(local_d);
469 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
472 if (padding == RSA_X931_PADDING)
474 BN_sub(f, rsa->n, ret);
475 if (BN_cmp(ret, f) > 0)
483 /* put in leading 0 bytes if the number is less than the
484 * length of the modulus */
486 i=BN_bn2bin(res,&(to[num-j]));
487 for (k=0; k<(num-i); k++)
499 OPENSSL_cleanse(buf,num);
505 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
506 unsigned char *to, RSA *rsa, int padding)
511 unsigned char *buf=NULL;
513 int local_blinding = 0;
514 /* Used only if the blinding structure is shared. A non-NULL unblind
515 * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
516 * the unblinding factor outside the blinding structure. */
517 BIGNUM *unblind = NULL;
518 BN_BLINDING *blinding = NULL;
520 if((ctx = BN_CTX_new()) == NULL) goto err;
523 ret = BN_CTX_get(ctx);
524 num = BN_num_bytes(rsa->n);
525 buf = OPENSSL_malloc(num);
526 if(!f || !ret || !buf)
528 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
532 /* This check was for equality but PGP does evil things
533 * and chops off the top '0' bytes */
536 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
540 /* make data into a big number */
541 if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
543 if (BN_ucmp(f, rsa->n) >= 0)
545 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
549 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
551 blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
552 if (blinding == NULL)
554 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
559 if (blinding != NULL)
561 if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL))
563 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
566 if (!rsa_blinding_convert(blinding, f, unblind, ctx))
571 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
574 (rsa->dmp1 != NULL) &&
575 (rsa->dmq1 != NULL) &&
576 (rsa->iqmp != NULL)) )
578 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
582 BIGNUM *d = NULL, *local_d = NULL;
584 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
586 local_d = d = BN_new();
589 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
592 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
597 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
598 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
600 if(local_d) BN_free(local_d);
603 if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
606 if(local_d) BN_free(local_d);
609 if(local_d) BN_free(local_d);
613 if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
617 j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
621 case RSA_PKCS1_PADDING:
622 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
624 #ifndef OPENSSL_NO_SHA
625 case RSA_PKCS1_OAEP_PADDING:
626 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
629 case RSA_SSLV23_PADDING:
630 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
633 r=RSA_padding_check_none(to,num,buf,j,num);
636 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
640 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
650 OPENSSL_cleanse(buf,num);
656 /* signature verification */
657 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
658 unsigned char *to, RSA *rsa, int padding)
663 unsigned char *buf=NULL;
666 if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
668 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
672 if (BN_ucmp(rsa->n, rsa->e) <= 0)
674 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
678 /* for large moduli, enforce exponent limit */
679 if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
681 if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
683 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
688 if((ctx = BN_CTX_new()) == NULL) goto err;
691 ret = BN_CTX_get(ctx);
692 num=BN_num_bytes(rsa->n);
693 buf = OPENSSL_malloc(num);
694 if(!f || !ret || !buf)
696 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
700 /* This check was for equality but PGP does evil things
701 * and chops off the top '0' bytes */
704 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
708 if (BN_bin2bn(from,flen,f) == NULL) goto err;
710 if (BN_ucmp(f, rsa->n) >= 0)
712 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
716 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
717 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
720 if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
721 rsa->_method_mod_n)) goto err;
723 if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12))
724 if (!BN_sub(ret, rsa->n, ret)) goto err;
731 case RSA_PKCS1_PADDING:
732 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
734 case RSA_X931_PADDING:
735 r=RSA_padding_check_X931(to,num,buf,i,num);
738 r=RSA_padding_check_none(to,num,buf,i,num);
741 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
745 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
755 OPENSSL_cleanse(buf,num);
761 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
763 BIGNUM *r1,*m1,*vrfy;
764 BIGNUM *local_dmp1, *local_dmq1, *local_c, *local_r1;
765 BIGNUM *dmp1,*dmq1,*c,*pr1;
769 local_dmp1 = BN_new();
770 local_dmq1 = BN_new();
773 if(!local_dmp1 || !local_dmq1 || !local_c || !local_r1)
777 r1 = BN_CTX_get(ctx);
778 m1 = BN_CTX_get(ctx);
779 vrfy = BN_CTX_get(ctx);
782 BIGNUM *local_p = NULL, *local_q = NULL;
783 BIGNUM *p = NULL, *q = NULL;
785 /* Make sure BN_mod_inverse in Montgomery intialization uses the
786 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
788 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
790 local_p = p = BN_new();
792 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
794 local_q = q = BN_new();
800 BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
808 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
810 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx) || !BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
812 if(local_p) BN_free(local_p);
813 if(local_q) BN_free(local_q);
817 if(local_p) BN_free(local_p);
818 if(local_q) BN_free(local_q);
821 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
822 if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
825 /* compute I mod q */
826 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
829 BN_with_flags(c, I, BN_FLG_CONSTTIME);
830 if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
834 if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
837 /* compute r1^dmq1 mod q */
838 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
841 BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
845 if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
846 rsa->_method_mod_q)) goto err;
848 /* compute I mod p */
849 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
852 BN_with_flags(c, I, BN_FLG_CONSTTIME);
853 if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
857 if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
860 /* compute r1^dmp1 mod p */
861 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
864 BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
868 if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
869 rsa->_method_mod_p)) goto err;
871 if (!BN_sub(r0,r0,m1)) goto err;
872 /* This will help stop the size of r0 increasing, which does
873 * affect the multiply if it optimised for a power of 2 size */
874 if (BN_is_negative(r0))
875 if (!BN_add(r0,r0,rsa->p)) goto err;
877 if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
879 /* Turn BN_FLG_CONSTTIME flag on before division operation */
880 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
883 BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
887 if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;
889 /* If p < q it is occasionally possible for the correction of
890 * adding 'p' if r0 is negative above to leave the result still
891 * negative. This can break the private key operations: the following
892 * second correction should *always* correct this rare occurrence.
893 * This will *never* happen with OpenSSL generated keys because
894 * they ensure p > q [steve]
896 if (BN_is_negative(r0))
897 if (!BN_add(r0,r0,rsa->p)) goto err;
898 if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
899 if (!BN_add(r0,r1,m1)) goto err;
901 if (rsa->e && rsa->n)
903 if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
904 /* If 'I' was greater than (or equal to) rsa->n, the operation
905 * will be equivalent to using 'I mod n'. However, the result of
906 * the verify will *always* be less than 'n' so we don't check
907 * for absolute equality, just congruency. */
908 if (!BN_sub(vrfy, vrfy, I)) goto err;
909 if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
910 if (BN_is_negative(vrfy))
911 if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
912 if (!BN_is_zero(vrfy))
914 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
915 * miscalculated CRT output, just do a raw (slower)
916 * mod_exp and return that instead. */
918 BIGNUM *local_d = NULL;
921 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
923 local_d = d = BN_new();
925 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
929 if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
932 if(local_d) BN_free(local_d);
936 if(local_d) BN_free(local_d);
941 if(local_dmp1) BN_free(local_dmp1);
942 if(local_dmq1) BN_free(local_dmq1);
943 if(local_c) BN_free(local_c);
944 if(local_r1) BN_free(local_r1);
949 static int RSA_eay_init(RSA *rsa)
951 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
955 static int RSA_eay_finish(RSA *rsa)
957 if (rsa->_method_mod_n != NULL)
958 BN_MONT_CTX_free(rsa->_method_mod_n);
959 if (rsa->_method_mod_p != NULL)
960 BN_MONT_CTX_free(rsa->_method_mod_p);
961 if (rsa->_method_mod_q != NULL)
962 BN_MONT_CTX_free(rsa->_method_mod_q);