/* crypto/rsa/rsa_eay.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include <stdio.h>
#include "cryptlib.h"
#include <openssl/bn.h>
#include <openssl/rsa.h>
#include <openssl/rand.h>
#ifndef RSA_NULL
static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa,int padding);
static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa,int padding);
static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa,int padding);
static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa,int padding);
static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx);
static int RSA_eay_init(RSA *rsa);
static int RSA_eay_finish(RSA *rsa);
static RSA_METHOD rsa_pkcs1_eay_meth={
"Eric Young's PKCS#1 RSA",
RSA_eay_public_encrypt,
RSA_eay_public_decrypt, /* signature verification */
RSA_eay_private_encrypt, /* signing */
RSA_eay_private_decrypt,
RSA_eay_mod_exp,
BN_mod_exp_mont, /* XXX probably we should not use Montgomery if e == 3 */
RSA_eay_init,
RSA_eay_finish,
0, /* flags */
NULL,
0, /* rsa_sign */
0, /* rsa_verify */
NULL /* rsa_keygen */
};
const RSA_METHOD *RSA_PKCS1_SSLeay(void)
{
return(&rsa_pkcs1_eay_meth);
}
/* Usage example;
* MONT_HELPER(rsa->_method_mod_p, bn_ctx, rsa->p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
*/
#define MONT_HELPER(method_mod, ctx, m, pre_cond, err_instr) \
if ((pre_cond) && ((method_mod) == NULL) && \
!BN_MONT_CTX_set_locked(&(method_mod), \
CRYPTO_LOCK_RSA, \
(m), (ctx))) \
err_instr
static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding)
{
BIGNUM *f,*ret;
int i,j,k,num=0,r= -1;
unsigned char *buf=NULL;
BN_CTX *ctx=NULL;
if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
return -1;
}
if (BN_ucmp(rsa->n, rsa->e) <= 0)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
return -1;
}
/* for large moduli, enforce exponent limit */
if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
{
if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
return -1;
}
}
if ((ctx=BN_CTX_new()) == NULL) goto err;
BN_CTX_start(ctx);
f = BN_CTX_get(ctx);
ret = BN_CTX_get(ctx);
num=BN_num_bytes(rsa->n);
buf = OPENSSL_malloc(num);
if (!f || !ret || !buf)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
goto err;
}
switch (padding)
{
case RSA_PKCS1_PADDING:
i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
break;
#ifndef OPENSSL_NO_SHA
case RSA_PKCS1_OAEP_PADDING:
i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
break;
#endif
case RSA_SSLV23_PADDING:
i=RSA_padding_add_SSLv23(buf,num,from,flen);
break;
case RSA_NO_PADDING:
i=RSA_padding_add_none(buf,num,from,flen);
break;
default:
RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
goto err;
}
if (i <= 0) goto err;
if (BN_bin2bn(buf,num,f) == NULL) goto err;
if (BN_ucmp(f, rsa->n) >= 0)
{
/* usually the padding functions would catch this */
RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
goto err;
}
MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
rsa->_method_mod_n)) goto err;
/* put in leading 0 bytes if the number is less than the
* length of the modulus */
j=BN_num_bytes(ret);
i=BN_bn2bin(ret,&(to[num-j]));
for (k=0; k<(num-i); k++)
to[k]=0;
r=num;
err:
if (ctx != NULL)
{
BN_CTX_end(ctx);
BN_CTX_free(ctx);
}
if (buf != NULL)
{
OPENSSL_cleanse(buf,num);
OPENSSL_free(buf);
}
return(r);
}
static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
{
BN_BLINDING *ret;
int got_write_lock = 0;
CRYPTO_r_lock(CRYPTO_LOCK_RSA);
if (rsa->blinding == NULL)
{
CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
CRYPTO_w_lock(CRYPTO_LOCK_RSA);
got_write_lock = 1;
if (rsa->blinding == NULL)
rsa->blinding = RSA_setup_blinding(rsa, ctx);
}
ret = rsa->blinding;
if (ret == NULL)
goto err;
if (BN_BLINDING_get_thread_id(ret) == CRYPTO_thread_id())
{
/* rsa->blinding is ours! */
*local = 1;
}
else
{
/* resort to rsa->mt_blinding instead */
*local = 0; /* instructs rsa_blinding_convert(), rsa_blinding_invert()
* that the BN_BLINDING is shared, meaning that accesses
* require locks, and that the blinding factor must be
* stored outside the BN_BLINDING
*/
if (rsa->mt_blinding == NULL)
{
if (!got_write_lock)
{
CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
CRYPTO_w_lock(CRYPTO_LOCK_RSA);
got_write_lock = 1;
}
if (rsa->mt_blinding == NULL)
rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
}
ret = rsa->mt_blinding;
}
err:
if (got_write_lock)
CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
else
CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
return ret;
}
static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f,
BIGNUM *r, BN_CTX *ctx)
{
if (local)
return BN_BLINDING_convert_ex(f, NULL, b, ctx);
else
{
int ret;
CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING);
ret = BN_BLINDING_convert_ex(f, r, b, ctx);
CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING);
return ret;
}
}
static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f,
BIGNUM *r, BN_CTX *ctx)
{
if (local)
return BN_BLINDING_invert_ex(f, NULL, b, ctx);
else
{
int ret;
CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
ret = BN_BLINDING_invert_ex(f, r, b, ctx);
CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
return ret;
}
}
/* signing */
static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding)
{
BIGNUM *f, *ret, *br, *res;
int i,j,k,num=0,r= -1;
unsigned char *buf=NULL;
BN_CTX *ctx=NULL;
int local_blinding = 0;
BN_BLINDING *blinding = NULL;
if ((ctx=BN_CTX_new()) == NULL) goto err;
BN_CTX_start(ctx);
f = BN_CTX_get(ctx);
br = BN_CTX_get(ctx);
ret = BN_CTX_get(ctx);
num = BN_num_bytes(rsa->n);
buf = OPENSSL_malloc(num);
if(!f || !ret || !buf)
{
RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
goto err;
}
switch (padding)
{
case RSA_PKCS1_PADDING:
i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
break;
case RSA_X931_PADDING:
i=RSA_padding_add_X931(buf,num,from,flen);
break;
case RSA_NO_PADDING:
i=RSA_padding_add_none(buf,num,from,flen);
break;
case RSA_SSLV23_PADDING:
default:
RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
goto err;
}
if (i <= 0) goto err;
if (BN_bin2bn(buf,num,f) == NULL) goto err;
if (BN_ucmp(f, rsa->n) >= 0)
{
/* usually the padding functions would catch this */
RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
goto err;
}
if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
{
blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
if (blinding == NULL)
{
RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
goto err;
}
}
if (blinding != NULL)
if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
goto err;
if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
((rsa->p != NULL) &&
(rsa->q != NULL) &&
(rsa->dmp1 != NULL) &&
(rsa->dmq1 != NULL) &&
(rsa->iqmp != NULL)) )
{
if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
}
else
{
BIGNUM local_d;
BIGNUM *d = NULL;
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
BN_init(&local_d);
d = &local_d;
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
}
else
d= rsa->d;
MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
rsa->_method_mod_n)) goto err;
}
if (blinding)
if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
goto err;
if (padding == RSA_X931_PADDING)
{
BN_sub(f, rsa->n, ret);
if (BN_cmp(ret, f))
res = f;
else
res = ret;
}
else
res = ret;
/* put in leading 0 bytes if the number is less than the
* length of the modulus */
j=BN_num_bytes(res);
i=BN_bn2bin(res,&(to[num-j]));
for (k=0; k<(num-i); k++)
to[k]=0;
r=num;
err:
if (ctx != NULL)
{
BN_CTX_end(ctx);
BN_CTX_free(ctx);
}
if (buf != NULL)
{
OPENSSL_cleanse(buf,num);
OPENSSL_free(buf);
}
return(r);
}
static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding)
{
BIGNUM *f, *ret, *br;
int j,num=0,r= -1;
unsigned char *p;
unsigned char *buf=NULL;
BN_CTX *ctx=NULL;
int local_blinding = 0;
BN_BLINDING *blinding = NULL;
if((ctx = BN_CTX_new()) == NULL) goto err;
BN_CTX_start(ctx);
f = BN_CTX_get(ctx);
br = BN_CTX_get(ctx);
ret = BN_CTX_get(ctx);
num = BN_num_bytes(rsa->n);
buf = OPENSSL_malloc(num);
if(!f || !ret || !buf)
{
RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
goto err;
}
/* This check was for equality but PGP does evil things
* and chops off the top '0' bytes */
if (flen > num)
{
RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
goto err;
}
/* make data into a big number */
if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;
if (BN_ucmp(f, rsa->n) >= 0)
{
RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
goto err;
}
if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
{
blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
if (blinding == NULL)
{
RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
goto err;
}
}
if (blinding != NULL)
if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
goto err;
/* do the decrypt */
if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
((rsa->p != NULL) &&
(rsa->q != NULL) &&
(rsa->dmp1 != NULL) &&
(rsa->dmq1 != NULL) &&
(rsa->iqmp != NULL)) )
{
if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
}
else
{
BIGNUM local_d;
BIGNUM *d = NULL;
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
d = &local_d;
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
}
else
d = rsa->d;
MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
rsa->_method_mod_n))
goto err;
}
if (blinding)
if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
goto err;
p=buf;
j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
switch (padding)
{
case RSA_PKCS1_PADDING:
r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
break;
#ifndef OPENSSL_NO_SHA
case RSA_PKCS1_OAEP_PADDING:
r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
break;
#endif
case RSA_SSLV23_PADDING:
r=RSA_padding_check_SSLv23(to,num,buf,j,num);
break;
case RSA_NO_PADDING:
r=RSA_padding_check_none(to,num,buf,j,num);
break;
default:
RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
goto err;
}
if (r < 0)
RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
err:
if (ctx != NULL)
{
BN_CTX_end(ctx);
BN_CTX_free(ctx);
}
if (buf != NULL)
{
OPENSSL_cleanse(buf,num);
OPENSSL_free(buf);
}
return(r);
}
/* signature verification */
static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding)
{
BIGNUM *f,*ret;
int i,num=0,r= -1;
unsigned char *p;
unsigned char *buf=NULL;
BN_CTX *ctx=NULL;
if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
return -1;
}
if (BN_ucmp(rsa->n, rsa->e) <= 0)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
return -1;
}
/* for large moduli, enforce exponent limit */
if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
{
if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
return -1;
}
}
if((ctx = BN_CTX_new()) == NULL) goto err;
BN_CTX_start(ctx);
f = BN_CTX_get(ctx);
ret = BN_CTX_get(ctx);
num=BN_num_bytes(rsa->n);
buf = OPENSSL_malloc(num);
if(!f || !ret || !buf)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
goto err;
}
/* This check was for equality but PGP does evil things
* and chops off the top '0' bytes */
if (flen > num)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
goto err;
}
if (BN_bin2bn(from,flen,f) == NULL) goto err;
if (BN_ucmp(f, rsa->n) >= 0)
{
RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
goto err;
}
MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
rsa->_method_mod_n)) goto err;
if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
BN_sub(ret, rsa->n, ret);
p=buf;
i=BN_bn2bin(ret,p);
switch (padding)
{
case RSA_PKCS1_PADDING:
r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
break;
case RSA_X931_PADDING:
r=RSA_padding_check_X931(to,num,buf,i,num);
break;
case RSA_NO_PADDING:
r=RSA_padding_check_none(to,num,buf,i,num);
break;
default:
RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
goto err;
}
if (r < 0)
RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
err:
if (ctx != NULL)
{
BN_CTX_end(ctx);
BN_CTX_free(ctx);
}
if (buf != NULL)
{
OPENSSL_cleanse(buf,num);
OPENSSL_free(buf);
}
return(r);
}
static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
{
BIGNUM *r1,*m1,*vrfy;
BIGNUM local_dmp1,local_dmq1,local_c,local_r1;
BIGNUM *dmp1,*dmq1,*c,*pr1;
int ret=0;
BN_CTX_start(ctx);
r1 = BN_CTX_get(ctx);
m1 = BN_CTX_get(ctx);
vrfy = BN_CTX_get(ctx);
{
BIGNUM local_p, local_q;
BIGNUM *p = NULL, *q = NULL;
/* Make sure BN_mod_inverse in Montgomery intialization uses the
* BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
*/
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
BN_init(&local_p);
p = &local_p;
BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
BN_init(&local_q);
q = &local_q;
BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
}
else
{
p = rsa->p;
q = rsa->q;
}
MONT_HELPER(rsa->_method_mod_p, ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
MONT_HELPER(rsa->_method_mod_q, ctx, q, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
}
MONT_HELPER(rsa->_method_mod_n, ctx, rsa->n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
/* compute I mod q */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
c = &local_c;
BN_with_flags(c, I, BN_FLG_CONSTTIME);
if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
}
else
{
if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
}
/* compute r1^dmq1 mod q */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
dmq1 = &local_dmq1;
BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
}
else
dmq1 = rsa->dmq1;
if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
rsa->_method_mod_q)) goto err;
/* compute I mod p */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
c = &local_c;
BN_with_flags(c, I, BN_FLG_CONSTTIME);
if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
}
else
{
if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
}
/* compute r1^dmp1 mod p */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
dmp1 = &local_dmp1;
BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
}
else
dmp1 = rsa->dmp1;
if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
rsa->_method_mod_p)) goto err;
if (!BN_sub(r0,r0,m1)) goto err;
/* This will help stop the size of r0 increasing, which does
* affect the multiply if it optimised for a power of 2 size */
if (BN_is_negative(r0))
if (!BN_add(r0,r0,rsa->p)) goto err;
if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;
/* Turn BN_FLG_CONSTTIME flag on before division operation */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
pr1 = &local_r1;
BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
}
else
pr1 = r1;
if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;
/* If p < q it is occasionally possible for the correction of
* adding 'p' if r0 is negative above to leave the result still
* negative. This can break the private key operations: the following
* second correction should *always* correct this rare occurrence.
* This will *never* happen with OpenSSL generated keys because
* they ensure p > q [steve]
*/
if (BN_is_negative(r0))
if (!BN_add(r0,r0,rsa->p)) goto err;
if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
if (!BN_add(r0,r1,m1)) goto err;
if (rsa->e && rsa->n)
{
if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
/* If 'I' was greater than (or equal to) rsa->n, the operation
* will be equivalent to using 'I mod n'. However, the result of
* the verify will *always* be less than 'n' so we don't check
* for absolute equality, just congruency. */
if (!BN_sub(vrfy, vrfy, I)) goto err;
if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
if (BN_is_negative(vrfy))
if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
if (!BN_is_zero(vrfy))
{
/* 'I' and 'vrfy' aren't congruent mod n. Don't leak
* miscalculated CRT output, just do a raw (slower)
* mod_exp and return that instead. */
BIGNUM local_d;
BIGNUM *d = NULL;
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
d = &local_d;
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
}
else
d = rsa->d;
if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
rsa->_method_mod_n)) goto err;
}
}
ret=1;
err:
BN_CTX_end(ctx);
return(ret);
}
static int RSA_eay_init(RSA *rsa)
{
rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
return(1);
}
static int RSA_eay_finish(RSA *rsa)
{
if (rsa->_method_mod_n != NULL)
BN_MONT_CTX_free(rsa->_method_mod_n);
if (rsa->_method_mod_p != NULL)
BN_MONT_CTX_free(rsa->_method_mod_p);
if (rsa->_method_mod_q != NULL)
BN_MONT_CTX_free(rsa->_method_mod_q);
return(1);
}
#endif