/* ====================================================================
* 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).
*
* 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.] */
#include <openssl/rsa.h>
#include <string.h>
#include <openssl/bn.h>
#include <openssl/mem.h>
#include <openssl/err.h>
#include <openssl/thread.h>
#include "internal.h"
#define BN_BLINDING_COUNTER 32
struct bn_blinding_st {
BIGNUM *A;
BIGNUM *Ai;
BIGNUM *e;
BIGNUM *mod; /* just a reference */
int counter;
unsigned long flags;
BN_MONT_CTX *m_ctx;
int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
};
BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod) {
BN_BLINDING *ret = NULL;
ret = (BN_BLINDING*) OPENSSL_malloc(sizeof(BN_BLINDING));
if (ret == NULL) {
OPENSSL_PUT_ERROR(RSA, BN_BLINDING_new, ERR_R_MALLOC_FAILURE);
return NULL;
}
memset(ret, 0, sizeof(BN_BLINDING));
if (A != NULL) {
ret->A = BN_dup(A);
if (ret->A == NULL) {
goto err;
}
}
if (Ai != NULL) {
ret->Ai = BN_dup(Ai);
if (ret->Ai == NULL) {
goto err;
}
}
/* save a copy of mod in the BN_BLINDING structure */
ret->mod = BN_dup(mod);
if (ret->mod == NULL) {
goto err;
}
if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0) {
BN_set_flags(ret->mod, BN_FLG_CONSTTIME);
}
/* Set the counter to the special value -1
* to indicate that this is never-used fresh blinding
* that does not need updating before first use. */
ret->counter = -1;
return ret;
err:
BN_BLINDING_free(ret);
return NULL;
}
void BN_BLINDING_free(BN_BLINDING *r) {
if (r == NULL) {
return;
}
BN_free(r->A);
BN_free(r->Ai);
BN_free(r->e);
BN_free(r->mod);
OPENSSL_free(r);
}
int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx) {
int ret = 0;
if (b->A == NULL || b->Ai == NULL) {
OPENSSL_PUT_ERROR(RSA, BN_BLINDING_update, RSA_R_BN_NOT_INITIALIZED);
goto err;
}
if (b->counter == -1) {
b->counter = 0;
}
if (++b->counter == BN_BLINDING_COUNTER && b->e != NULL &&
!(b->flags & BN_BLINDING_NO_RECREATE)) {
/* re-create blinding parameters */
if (!BN_BLINDING_create_param(b, NULL, NULL, ctx, NULL, NULL)) {
goto err;
}
} else if (!(b->flags & BN_BLINDING_NO_UPDATE)) {
if (!BN_mod_mul(b->A, b->A, b->A, b->mod, ctx)) {
goto err;
}
if (!BN_mod_mul(b->Ai, b->Ai, b->Ai, b->mod, ctx)) {
goto err;
}
}
ret = 1;
err:
if (b->counter == BN_BLINDING_COUNTER) {
b->counter = 0;
}
return ret;
}
int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx) {
return BN_BLINDING_convert_ex(n, NULL, b, ctx);
}
int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx) {
int ret = 1;
if (b->A == NULL || b->Ai == NULL) {
OPENSSL_PUT_ERROR(RSA, BN_BLINDING_convert_ex, RSA_R_BN_NOT_INITIALIZED);
return 0;
}
if (b->counter == -1) {
/* Fresh blinding, doesn't need updating. */
b->counter = 0;
} else if (!BN_BLINDING_update(b, ctx)) {
return 0;
}
if (r != NULL) {
if (!BN_copy(r, b->Ai)) {
ret = 0;
}
}
if (!BN_mod_mul(n, n, b->A, b->mod, ctx)) {
ret = 0;
}
return ret;
}
int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx) {
return BN_BLINDING_invert_ex(n, NULL, b, ctx);
}
int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b,
BN_CTX *ctx) {
int ret;
if (r != NULL) {
ret = BN_mod_mul(n, n, r, b->mod, ctx);
} else {
if (b->Ai == NULL) {
OPENSSL_PUT_ERROR(RSA, BN_BLINDING_invert_ex, RSA_R_BN_NOT_INITIALIZED);
return 0;
}
ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
}
return ret;
}
unsigned long BN_BLINDING_get_flags(const BN_BLINDING *b) { return b->flags; }
void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags) {
b->flags = flags;
}
BN_BLINDING *BN_BLINDING_create_param(
BN_BLINDING *b, const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
BN_MONT_CTX *m_ctx) {
int retry_counter = 32;
BN_BLINDING *ret = NULL;
if (b == NULL) {
ret = BN_BLINDING_new(NULL, NULL, m);
} else {
ret = b;
}
if (ret == NULL) {
goto err;
}
if (ret->A == NULL && (ret->A = BN_new()) == NULL) {
goto err;
}
if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL) {
goto err;
}
if (e != NULL) {
BN_free(ret->e);
ret->e = BN_dup(e);
}
if (ret->e == NULL) {
goto err;
}
if (bn_mod_exp != NULL) {
ret->bn_mod_exp = bn_mod_exp;
}
if (m_ctx != NULL) {
ret->m_ctx = m_ctx;
}
do {
if (!BN_rand_range(ret->A, ret->mod)) {
goto err;
}
if (BN_mod_inverse(ret->Ai, ret->A, ret->mod, ctx) == NULL) {
/* this should almost never happen for good RSA keys */
uint32_t error = ERR_peek_last_error();
if (ERR_GET_REASON(error) == BN_R_NO_INVERSE) {
if (retry_counter-- == 0) {
OPENSSL_PUT_ERROR(RSA, BN_BLINDING_create_param,
RSA_R_TOO_MANY_ITERATIONS);
goto err;
}
ERR_clear_error();
} else {
goto err;
}
} else {
break;
}
} while (1);
if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL) {
if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx)) {
goto err;
}
} else {
if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx)) {
goto err;
}
}
return ret;
err:
if (b == NULL) {
BN_BLINDING_free(ret);
ret = NULL;
}
return ret;
}
static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,
const BIGNUM *q, BN_CTX *ctx) {
BIGNUM *ret = NULL, *r0, *r1, *r2;
if (d == NULL || p == NULL || q == NULL) {
return NULL;
}
BN_CTX_start(ctx);
r0 = BN_CTX_get(ctx);
r1 = BN_CTX_get(ctx);
r2 = BN_CTX_get(ctx);
if (r2 == NULL) {
goto err;
}
if (!BN_sub(r1, p, BN_value_one())) {
goto err;
}
if (!BN_sub(r2, q, BN_value_one())) {
goto err;
}
if (!BN_mul(r0, r1, r2, ctx)) {
goto err;
}
ret = BN_mod_inverse(NULL, d, r0, ctx);
err:
BN_CTX_end(ctx);
return ret;
}
BN_BLINDING *rsa_setup_blinding(RSA *rsa, BN_CTX *in_ctx) {
BIGNUM local_n;
BIGNUM *e, *n;
BN_CTX *ctx;
BN_BLINDING *ret = NULL;
BN_MONT_CTX *mont_ctx = NULL;
if (in_ctx == NULL) {
ctx = BN_CTX_new();
if (ctx == NULL) {
return 0;
}
} else {
ctx = in_ctx;
}
BN_CTX_start(ctx);
e = BN_CTX_get(ctx);
if (e == NULL) {
OPENSSL_PUT_ERROR(RSA, rsa_setup_blinding, ERR_R_MALLOC_FAILURE);
goto err;
}
if (rsa->e == NULL) {
e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
if (e == NULL) {
OPENSSL_PUT_ERROR(RSA, rsa_setup_blinding, RSA_R_NO_PUBLIC_EXPONENT);
goto err;
}
} else {
e = rsa->e;
}
n = &local_n;
BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC) {
mont_ctx =
BN_MONT_CTX_set_locked(&rsa->_method_mod_n, &rsa->lock, rsa->n, ctx);
if (mont_ctx == NULL) {
goto err;
}
}
ret = BN_BLINDING_create_param(NULL, e, n, ctx, rsa->meth->bn_mod_exp,
mont_ctx);
if (ret == NULL) {
OPENSSL_PUT_ERROR(RSA, rsa_setup_blinding, ERR_R_BN_LIB);
goto err;
}
err:
BN_CTX_end(ctx);
if (in_ctx == NULL) {
BN_CTX_free(ctx);
}
if (rsa->e == NULL) {
BN_free(e);
}
return ret;
}