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openssl/crypto/rsa/rsa_ossl.c
Richard Levitte 9862e9aa98 Make the RSA structure opaque 
Move rsa_st away from public headers.
Add accessor/writer functions for the public RSA data.
Adapt all other source to use the accessors and writers.

Reviewed-by: Matt Caswell <matt@openssl.org>
2016-04-06 16:19:17 +02:00

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/* 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 "internal/cryptlib.h"
#include "internal/bn_int.h"
#include <openssl/rand.h>
#include "rsa_locl.h"
#ifndef RSA_NULL
static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
static int rsa_ossl_private_encrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
static int rsa_ossl_public_decrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
static int rsa_ossl_private_decrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa,
BN_CTX *ctx);
static int rsa_ossl_init(RSA *rsa);
static int rsa_ossl_finish(RSA *rsa);
static RSA_METHOD rsa_pkcs1_ossl_meth = {
"OpenSSL PKCS#1 RSA (from Eric Young)",
rsa_ossl_public_encrypt,
rsa_ossl_public_decrypt, /* signature verification */
rsa_ossl_private_encrypt, /* signing */
rsa_ossl_private_decrypt,
rsa_ossl_mod_exp,
BN_mod_exp_mont, /* XXX probably we should not use Montgomery
* if e == 3 */
rsa_ossl_init,
rsa_ossl_finish,
RSA_FLAG_FIPS_METHOD, /* flags */
NULL,
0, /* rsa_sign */
0, /* rsa_verify */
NULL /* rsa_keygen */
};
const RSA_METHOD *RSA_PKCS1_OpenSSL(void)
{
return &rsa_pkcs1_ossl_meth;
}
static int rsa_ossl_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_OSSL_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
return -1;
}
if (BN_ucmp(rsa->n, rsa->e) <= 0) {
RSAerr(RSA_F_RSA_OSSL_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_OSSL_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 == NULL || ret == NULL || buf == NULL) {
RSAerr(RSA_F_RSA_OSSL_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;
case RSA_PKCS1_OAEP_PADDING:
i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
break;
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_OSSL_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_OSSL_PUBLIC_ENCRYPT,
RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
goto err;
}
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
if (!BN_MONT_CTX_set_locked
(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))
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);
OPENSSL_clear_free(buf, num);
return (r);
}
static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
{
BN_BLINDING *ret;
CRYPTO_THREAD_write_lock(rsa->lock);
if (rsa->blinding == NULL) {
rsa->blinding = RSA_setup_blinding(rsa, ctx);
}
ret = rsa->blinding;
if (ret == NULL)
goto err;
if (BN_BLINDING_is_current_thread(ret)) {
/* rsa->blinding is ours! */
*local = 1;
} else {
/* resort to rsa->mt_blinding instead */
/*
* 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
*/
*local = 0;
if (rsa->mt_blinding == NULL) {
rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
}
ret = rsa->mt_blinding;
}
err:
CRYPTO_THREAD_unlock(rsa->lock);
return ret;
}
static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
BN_CTX *ctx)
{
if (unblind == NULL)
/*
* Local blinding: store the unblinding factor in BN_BLINDING.
*/
return BN_BLINDING_convert_ex(f, NULL, b, ctx);
else {
/*
* Shared blinding: store the unblinding factor outside BN_BLINDING.
*/
int ret;
BN_BLINDING_lock(b);
ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
BN_BLINDING_unlock(b);
return ret;
}
}
static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
BN_CTX *ctx)
{
/*
* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
* will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
* is shared between threads, unblind must be non-null:
* BN_BLINDING_invert_ex will then use the local unblinding factor, and
* will only read the modulus from BN_BLINDING. In both cases it's safe
* to access the blinding without a lock.
*/
return BN_BLINDING_invert_ex(f, unblind, b, ctx);
}
/* signing */
static int rsa_ossl_private_encrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding)
{
BIGNUM *f, *ret, *res;
int i, j, k, num = 0, r = -1;
unsigned char *buf = NULL;
BN_CTX *ctx = NULL;
int local_blinding = 0;
/*
* Used only if the blinding structure is shared. A non-NULL unblind
* instructs rsa_blinding_convert() and rsa_blinding_invert() to store
* the unblinding factor outside the blinding structure.
*/
BIGNUM *unblind = NULL;
BN_BLINDING *blinding = NULL;
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 == NULL || ret == NULL || buf == NULL) {
RSAerr(RSA_F_RSA_OSSL_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_OSSL_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_OSSL_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_OSSL_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
goto err;
}
}
if (blinding != NULL) {
if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!rsa_blinding_convert(blinding, f, unblind, 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 *d = NULL, *local_d = NULL;
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
local_d = d = BN_new();
if (d == NULL) {
RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
goto err;
}
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
} else {
d = rsa->d;
}
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
if (!BN_MONT_CTX_set_locked
(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) {
BN_free(local_d);
goto err;
}
if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
rsa->_method_mod_n)) {
BN_free(local_d);
goto err;
}
/* We MUST free local_d before any further use of rsa->d */
BN_free(local_d);
}
if (blinding)
if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
goto err;
if (padding == RSA_X931_PADDING) {
BN_sub(f, rsa->n, ret);
if (BN_cmp(ret, f) > 0)
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);
OPENSSL_clear_free(buf, num);
return (r);
}
static int rsa_ossl_private_decrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding)
{
BIGNUM *f, *ret;
int j, num = 0, r = -1;
unsigned char *p;
unsigned char *buf = NULL;
BN_CTX *ctx = NULL;
int local_blinding = 0;
/*
* Used only if the blinding structure is shared. A non-NULL unblind
* instructs rsa_blinding_convert() and rsa_blinding_invert() to store
* the unblinding factor outside the blinding structure.
*/
BIGNUM *unblind = NULL;
BN_BLINDING *blinding = NULL;
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 == NULL || ret == NULL || buf == NULL) {
RSAerr(RSA_F_RSA_OSSL_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_OSSL_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_OSSL_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_OSSL_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
goto err;
}
}
if (blinding != NULL) {
if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!rsa_blinding_convert(blinding, f, unblind, 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 *d = NULL, *local_d = NULL;
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
local_d = d = BN_new();
if (d == NULL) {
RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
goto err;
}
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
} else {
d = rsa->d;
}
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
if (!BN_MONT_CTX_set_locked
(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) {
BN_free(local_d);
goto err;
}
if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
rsa->_method_mod_n)) {
BN_free(local_d);
goto err;
}
/* We MUST free local_d before any further use of rsa->d */
BN_free(local_d);
}
if (blinding)
if (!rsa_blinding_invert(blinding, ret, unblind, 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;
case RSA_PKCS1_OAEP_PADDING:
r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
break;
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_OSSL_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
goto err;
}
if (r < 0)
RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
err:
if (ctx != NULL)
BN_CTX_end(ctx);
BN_CTX_free(ctx);
OPENSSL_clear_free(buf, num);
return (r);
}
/* signature verification */
static int rsa_ossl_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_OSSL_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
return -1;
}
if (BN_ucmp(rsa->n, rsa->e) <= 0) {
RSAerr(RSA_F_RSA_OSSL_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_OSSL_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 == NULL || ret == NULL || buf == NULL) {
RSAerr(RSA_F_RSA_OSSL_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_OSSL_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_OSSL_PUBLIC_DECRYPT,
RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
goto err;
}
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
if (!BN_MONT_CTX_set_locked
(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))
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) && ((bn_get_words(ret)[0] & 0xf) != 12))
if (!BN_sub(ret, rsa->n, ret))
goto err;
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_OSSL_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
goto err;
}
if (r < 0)
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
err:
if (ctx != NULL)
BN_CTX_end(ctx);
BN_CTX_free(ctx);
OPENSSL_clear_free(buf, num);
return (r);
}
static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
{
BIGNUM *r1, *m1, *vrfy;
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 = NULL, *local_q = NULL;
BIGNUM *p = NULL, *q = NULL;
/*
* Make sure BN_mod_inverse in Montgomery initialization uses the
* BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
*/
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
local_p = p = BN_new();
if (p == NULL)
goto err;
BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
local_q = q = BN_new();
if (q == NULL) {
BN_free(local_p);
goto err;
}
BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
} else {
p = rsa->p;
q = rsa->q;
}
if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
if (!BN_MONT_CTX_set_locked
(&rsa->_method_mod_p, rsa->lock, p, ctx)
|| !BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
rsa->lock, q, ctx)) {
BN_free(local_p);
BN_free(local_q);
goto err;
}
}
/*
* We MUST free local_p and local_q before any further use of rsa->p and
* rsa->q
*/
BN_free(local_p);
BN_free(local_q);
}
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
if (!BN_MONT_CTX_set_locked
(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))
goto err;
/* compute I mod q */
{
BIGNUM *local_c = NULL;
const BIGNUM *c;
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
local_c = BN_new();
if (local_c == NULL)
goto err;
BN_with_flags(local_c, I, BN_FLG_CONSTTIME);
c = local_c;
} else {
c = I;
}
if (!BN_mod(r1, c, rsa->q, ctx)) {
BN_free(local_c);
goto err;
}
{
BIGNUM *local_dmq1 = NULL, *dmq1;
/* compute r1^dmq1 mod q */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
dmq1 = local_dmq1 = BN_new();
if (local_dmq1 == NULL) {
BN_free(local_c);
goto err;
}
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)) {
BN_free(local_c);
BN_free(local_dmq1);
goto err;
}
/* We MUST free local_dmq1 before any further use of rsa->dmq1 */
BN_free(local_dmq1);
}
/* compute I mod p */
if (!BN_mod(r1, c, rsa->p, ctx)) {
BN_free(local_c);
goto err;
}
/* We MUST free local_c before any further use of I */
BN_free(local_c);
}
{
BIGNUM *local_dmp1 = NULL, *dmp1;
/* compute r1^dmp1 mod p */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
dmp1 = local_dmp1 = BN_new();
if (local_dmp1 == NULL)
goto err;
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)) {
BN_free(local_dmp1);
goto err;
}
/* We MUST free local_dmp1 before any further use of rsa->dmp1 */
BN_free(local_dmp1);
}
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;
{
BIGNUM *local_r1 = NULL, *pr1;
/* Turn BN_FLG_CONSTTIME flag on before division operation */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
pr1 = local_r1 = BN_new();
if (local_r1 == NULL)
goto err;
BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
} else {
pr1 = r1;
}
if (!BN_mod(r0, pr1, rsa->p, ctx)) {
BN_free(local_r1);
goto err;
}
/* We MUST free local_r1 before any further use of r1 */
BN_free(local_r1);
}
/*
* 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 = NULL;
BIGNUM *d = NULL;
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
local_d = d = BN_new();
if (d == NULL)
goto err;
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)) {
BN_free(local_d);
goto err;
}
/* We MUST free local_d before any further use of rsa->d */
BN_free(local_d);
}
}
ret = 1;
err:
BN_CTX_end(ctx);
return (ret);
}
static int rsa_ossl_init(RSA *rsa)
{
rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE;
return (1);
}
static int rsa_ossl_finish(RSA *rsa)
{
BN_MONT_CTX_free(rsa->_method_mod_n);
BN_MONT_CTX_free(rsa->_method_mod_p);
BN_MONT_CTX_free(rsa->_method_mod_q);
return (1);
}
#endif
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