862 lines
23 KiB
C
Executable File
862 lines
23 KiB
C
Executable File
/* $OpenBSD: rsa_eay.c,v 1.51 2019/11/02 13:52:31 jsing Exp $ */
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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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* All rights reserved.
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*
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* This package is an SSL implementation written
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* by Eric Young (eay@cryptsoft.com).
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* The implementation was written so as to conform with Netscapes SSL.
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*
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* This library is free for commercial and non-commercial use as long as
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* the following conditions are aheared to. The following conditions
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* apply to all code found in this distribution, be it the RC4, RSA,
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* lhash, DES, etc., code; not just the SSL code. The SSL documentation
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* included with this distribution is covered by the same copyright terms
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* except that the holder is Tim Hudson (tjh@cryptsoft.com).
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*
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* Copyright remains Eric Young's, and as such any Copyright notices in
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* the code are not to be removed.
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* If this package is used in a product, Eric Young should be given attribution
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* as the author of the parts of the library used.
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* This can be in the form of a textual message at program startup or
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* in documentation (online or textual) provided with the package.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* "This product includes cryptographic software written by
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* Eric Young (eay@cryptsoft.com)"
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* The word 'cryptographic' can be left out if the rouines from the library
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* being used are not cryptographic related :-).
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* 4. If you include any Windows specific code (or a derivative thereof) from
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* the apps directory (application code) you must include an acknowledgement:
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* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
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*
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* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* The licence and distribution terms for any publically available version or
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* derivative of this code cannot be changed. i.e. this code cannot simply be
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* copied and put under another distribution licence
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* [including the GNU Public Licence.]
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*/
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/* ====================================================================
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* Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* 3. All advertising materials mentioning features or use of this
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* software must display the following acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
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*
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* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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* endorse or promote products derived from this software without
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* prior written permission. For written permission, please contact
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* openssl-core@openssl.org.
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*
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* 5. Products derived from this software may not be called "OpenSSL"
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* nor may "OpenSSL" appear in their names without prior written
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* permission of the OpenSSL Project.
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*
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* 6. Redistributions of any form whatsoever must retain the following
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* acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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*
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* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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* ====================================================================
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*
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* This product includes cryptographic software written by Eric Young
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* (eay@cryptsoft.com). This product includes software written by Tim
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* Hudson (tjh@cryptsoft.com).
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*
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*/
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#include <stdio.h>
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#include <string.h>
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#include <openssl/opensslconf.h>
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#include <openssl/bn.h>
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#include <openssl/err.h>
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#include <openssl/rsa.h>
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#include "bn_lcl.h"
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static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding);
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static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding);
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static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding);
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static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding);
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static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa, BN_CTX *ctx);
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static int RSA_eay_init(RSA *rsa);
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static int RSA_eay_finish(RSA *rsa);
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static RSA_METHOD rsa_pkcs1_eay_meth = {
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.name = "Eric Young's PKCS#1 RSA",
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.rsa_pub_enc = RSA_eay_public_encrypt,
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.rsa_pub_dec = RSA_eay_public_decrypt, /* signature verification */
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.rsa_priv_enc = RSA_eay_private_encrypt, /* signing */
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.rsa_priv_dec = RSA_eay_private_decrypt,
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.rsa_mod_exp = RSA_eay_mod_exp,
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.bn_mod_exp = BN_mod_exp_mont_ct, /* XXX probably we should not use Montgomery if e == 3 */
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.init = RSA_eay_init,
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.finish = RSA_eay_finish,
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};
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const RSA_METHOD *
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RSA_PKCS1_OpenSSL(void)
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{
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return &rsa_pkcs1_eay_meth;
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}
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const RSA_METHOD *
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RSA_PKCS1_SSLeay(void)
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{
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return &rsa_pkcs1_eay_meth;
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}
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static int
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RSA_eay_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
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RSA *rsa, int padding)
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{
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BIGNUM *f, *ret;
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int i, j, k, num = 0, r = -1;
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unsigned char *buf = NULL;
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BN_CTX *ctx = NULL;
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if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
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RSAerror(RSA_R_MODULUS_TOO_LARGE);
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return -1;
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}
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if (BN_ucmp(rsa->n, rsa->e) <= 0) {
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RSAerror(RSA_R_BAD_E_VALUE);
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return -1;
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}
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/* for large moduli, enforce exponent limit */
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if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
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if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
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RSAerror(RSA_R_BAD_E_VALUE);
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return -1;
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}
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}
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if ((ctx = BN_CTX_new()) == NULL)
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goto err;
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BN_CTX_start(ctx);
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f = BN_CTX_get(ctx);
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ret = BN_CTX_get(ctx);
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num = BN_num_bytes(rsa->n);
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buf = malloc(num);
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if (f == NULL || ret == NULL || buf == NULL) {
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RSAerror(ERR_R_MALLOC_FAILURE);
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goto err;
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}
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switch (padding) {
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case RSA_PKCS1_PADDING:
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i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
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break;
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#ifndef OPENSSL_NO_SHA
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case RSA_PKCS1_OAEP_PADDING:
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i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
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break;
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#endif
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case RSA_NO_PADDING:
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i = RSA_padding_add_none(buf, num, from, flen);
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break;
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default:
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RSAerror(RSA_R_UNKNOWN_PADDING_TYPE);
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goto err;
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}
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if (i <= 0)
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goto err;
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if (BN_bin2bn(buf, num, f) == NULL)
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goto err;
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if (BN_ucmp(f, rsa->n) >= 0) {
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/* usually the padding functions would catch this */
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RSAerror(RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
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goto err;
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}
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if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
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if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
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CRYPTO_LOCK_RSA, rsa->n, ctx))
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goto err;
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if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
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rsa->_method_mod_n))
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goto err;
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/* put in leading 0 bytes if the number is less than the
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* length of the modulus */
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j = BN_num_bytes(ret);
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i = BN_bn2bin(ret, &(to[num - j]));
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for (k = 0; k < num - i; k++)
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to[k] = 0;
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r = num;
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err:
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if (ctx != NULL) {
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BN_CTX_end(ctx);
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BN_CTX_free(ctx);
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}
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freezero(buf, num);
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return r;
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}
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static BN_BLINDING *
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rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
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{
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BN_BLINDING *ret;
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int got_write_lock = 0;
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CRYPTO_THREADID cur;
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CRYPTO_r_lock(CRYPTO_LOCK_RSA);
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if (rsa->blinding == NULL) {
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CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
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CRYPTO_w_lock(CRYPTO_LOCK_RSA);
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got_write_lock = 1;
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if (rsa->blinding == NULL)
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rsa->blinding = RSA_setup_blinding(rsa, ctx);
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}
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ret = rsa->blinding;
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if (ret == NULL)
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goto err;
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CRYPTO_THREADID_current(&cur);
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if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) {
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/* rsa->blinding is ours! */
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*local = 1;
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} else {
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/* resort to rsa->mt_blinding instead */
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/*
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* Instruct rsa_blinding_convert(), rsa_blinding_invert()
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* that the BN_BLINDING is shared, meaning that accesses
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* require locks, and that the blinding factor must be
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* stored outside the BN_BLINDING
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*/
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*local = 0;
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if (rsa->mt_blinding == NULL) {
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if (!got_write_lock) {
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CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
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CRYPTO_w_lock(CRYPTO_LOCK_RSA);
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got_write_lock = 1;
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}
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if (rsa->mt_blinding == NULL)
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rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
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}
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ret = rsa->mt_blinding;
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}
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err:
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if (got_write_lock)
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CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
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else
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CRYPTO_r_unlock(CRYPTO_LOCK_RSA);
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return ret;
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}
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static int
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rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, BN_CTX *ctx)
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{
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if (unblind == NULL)
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/*
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* Local blinding: store the unblinding factor
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* in BN_BLINDING.
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*/
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return BN_BLINDING_convert_ex(f, NULL, b, ctx);
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else {
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/*
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* Shared blinding: store the unblinding factor
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* outside BN_BLINDING.
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*/
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int ret;
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CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
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ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
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CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
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return ret;
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}
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}
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static int
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rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind, BN_CTX *ctx)
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{
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/*
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* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
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* will use the unblinding factor stored in BN_BLINDING.
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* If BN_BLINDING is shared between threads, unblind must be non-null:
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* BN_BLINDING_invert_ex will then use the local unblinding factor,
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* and will only read the modulus from BN_BLINDING.
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* In both cases it's safe to access the blinding without a lock.
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*/
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return BN_BLINDING_invert_ex(f, unblind, b, ctx);
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}
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/* signing */
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static int
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RSA_eay_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
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RSA *rsa, int padding)
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{
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BIGNUM *f, *ret, *res;
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int i, j, k, num = 0, r = -1;
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unsigned char *buf = NULL;
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BN_CTX *ctx = NULL;
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int local_blinding = 0;
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/*
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* Used only if the blinding structure is shared. A non-NULL unblind
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* instructs rsa_blinding_convert() and rsa_blinding_invert() to store
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* the unblinding factor outside the blinding structure.
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*/
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BIGNUM *unblind = NULL;
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BN_BLINDING *blinding = NULL;
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if ((ctx = BN_CTX_new()) == NULL)
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goto err;
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BN_CTX_start(ctx);
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f = BN_CTX_get(ctx);
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ret = BN_CTX_get(ctx);
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num = BN_num_bytes(rsa->n);
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buf = malloc(num);
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if (f == NULL || ret == NULL || buf == NULL) {
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RSAerror(ERR_R_MALLOC_FAILURE);
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goto err;
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}
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switch (padding) {
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case RSA_PKCS1_PADDING:
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i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
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break;
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case RSA_X931_PADDING:
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i = RSA_padding_add_X931(buf, num, from, flen);
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break;
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case RSA_NO_PADDING:
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i = RSA_padding_add_none(buf, num, from, flen);
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break;
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default:
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RSAerror(RSA_R_UNKNOWN_PADDING_TYPE);
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goto err;
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}
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if (i <= 0)
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goto err;
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if (BN_bin2bn(buf, num, f) == NULL)
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goto err;
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if (BN_ucmp(f, rsa->n) >= 0) {
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/* usually the padding functions would catch this */
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RSAerror(RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
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goto err;
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}
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if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
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blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
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if (blinding == NULL) {
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RSAerror(ERR_R_INTERNAL_ERROR);
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goto err;
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}
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}
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if (blinding != NULL) {
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if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
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RSAerror(ERR_R_MALLOC_FAILURE);
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goto err;
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}
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if (!rsa_blinding_convert(blinding, f, unblind, ctx))
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goto err;
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}
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if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
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(rsa->p != NULL && rsa->q != NULL && rsa->dmp1 != NULL &&
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rsa->dmq1 != NULL && rsa->iqmp != NULL)) {
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if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
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goto err;
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} else {
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BIGNUM d;
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BN_init(&d);
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BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
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if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
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if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
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CRYPTO_LOCK_RSA, rsa->n, ctx))
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goto err;
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if (!rsa->meth->bn_mod_exp(ret, f, &d, rsa->n, ctx,
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rsa->_method_mod_n)) {
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goto err;
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}
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}
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if (blinding)
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if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
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goto err;
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if (padding == RSA_X931_PADDING) {
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BN_sub(f, rsa->n, ret);
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if (BN_cmp(ret, f) > 0)
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res = f;
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else
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res = ret;
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} else
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res = ret;
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/* put in leading 0 bytes if the number is less than the
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* length of the modulus */
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j = BN_num_bytes(res);
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i = BN_bn2bin(res, &(to[num - j]));
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for (k = 0; k < num - i; k++)
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to[k] = 0;
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r = num;
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err:
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if (ctx != NULL) {
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BN_CTX_end(ctx);
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BN_CTX_free(ctx);
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}
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freezero(buf, num);
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return r;
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}
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static int
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RSA_eay_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
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RSA *rsa, int padding)
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{
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BIGNUM *f, *ret;
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int j, num = 0, r = -1;
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unsigned char *p;
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unsigned char *buf = NULL;
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BN_CTX *ctx = NULL;
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int local_blinding = 0;
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/*
|
|
* 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 = malloc(num);
|
|
|
|
if (!f || !ret || !buf) {
|
|
RSAerror(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) {
|
|
RSAerror(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) {
|
|
RSAerror(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) {
|
|
RSAerror(ERR_R_INTERNAL_ERROR);
|
|
goto err;
|
|
}
|
|
}
|
|
|
|
if (blinding != NULL) {
|
|
if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
|
|
RSAerror(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;
|
|
|
|
BN_init(&d);
|
|
BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
|
|
|
|
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
|
|
if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
|
|
CRYPTO_LOCK_RSA, rsa->n, ctx))
|
|
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, 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;
|
|
#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_NO_PADDING:
|
|
r = RSA_padding_check_none(to, num, buf, j, num);
|
|
break;
|
|
default:
|
|
RSAerror(RSA_R_UNKNOWN_PADDING_TYPE);
|
|
goto err;
|
|
}
|
|
if (r < 0)
|
|
RSAerror(RSA_R_PADDING_CHECK_FAILED);
|
|
|
|
err:
|
|
if (ctx != NULL) {
|
|
BN_CTX_end(ctx);
|
|
BN_CTX_free(ctx);
|
|
}
|
|
freezero(buf, num);
|
|
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) {
|
|
RSAerror(RSA_R_MODULUS_TOO_LARGE);
|
|
return -1;
|
|
}
|
|
|
|
if (BN_ucmp(rsa->n, rsa->e) <= 0) {
|
|
RSAerror(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) {
|
|
RSAerror(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 = malloc(num);
|
|
|
|
if (!f || !ret || !buf) {
|
|
RSAerror(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) {
|
|
RSAerror(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) {
|
|
RSAerror(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,
|
|
CRYPTO_LOCK_RSA, 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 && (ret->d[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:
|
|
RSAerror(RSA_R_UNKNOWN_PADDING_TYPE);
|
|
goto err;
|
|
}
|
|
if (r < 0)
|
|
RSAerror(RSA_R_PADDING_CHECK_FAILED);
|
|
|
|
err:
|
|
if (ctx != NULL) {
|
|
BN_CTX_end(ctx);
|
|
BN_CTX_free(ctx);
|
|
}
|
|
freezero(buf, num);
|
|
return r;
|
|
}
|
|
|
|
static int
|
|
RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
|
|
{
|
|
BIGNUM *r1, *m1, *vrfy;
|
|
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);
|
|
if (r1 == NULL || m1 == NULL || vrfy == NULL) {
|
|
RSAerror(ERR_R_MALLOC_FAILURE);
|
|
goto err;
|
|
}
|
|
|
|
{
|
|
BIGNUM p, q;
|
|
|
|
/*
|
|
* Make sure BN_mod_inverse in Montgomery intialization uses the
|
|
* BN_FLG_CONSTTIME flag
|
|
*/
|
|
BN_init(&p);
|
|
BN_init(&q);
|
|
BN_with_flags(&p, rsa->p, BN_FLG_CONSTTIME);
|
|
BN_with_flags(&q, rsa->q, BN_FLG_CONSTTIME);
|
|
|
|
if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
|
|
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)) {
|
|
goto err;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
|
|
if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
|
|
CRYPTO_LOCK_RSA, rsa->n, ctx))
|
|
goto err;
|
|
|
|
/* compute I mod q */
|
|
BN_init(&c);
|
|
BN_with_flags(&c, I, BN_FLG_CONSTTIME);
|
|
|
|
if (!BN_mod_ct(r1, &c, rsa->q, ctx))
|
|
goto err;
|
|
|
|
/* compute r1^dmq1 mod q */
|
|
BN_init(&dmq1);
|
|
BN_with_flags(&dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
|
|
|
|
if (!rsa->meth->bn_mod_exp(m1, r1, &dmq1, rsa->q, ctx,
|
|
rsa->_method_mod_q))
|
|
goto err;
|
|
|
|
/* compute I mod p */
|
|
BN_with_flags(&c, I, BN_FLG_CONSTTIME);
|
|
|
|
if (!BN_mod_ct(r1, &c, rsa->p, ctx))
|
|
goto err;
|
|
|
|
/* compute r1^dmp1 mod p */
|
|
BN_init(&dmp1);
|
|
BN_with_flags(&dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
|
|
|
|
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 */
|
|
BN_init(&pr1);
|
|
BN_with_flags(&pr1, r1, BN_FLG_CONSTTIME);
|
|
|
|
if (!BN_mod_ct(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_ct(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 d;
|
|
|
|
BN_init(&d);
|
|
BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
|
|
|
|
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)
|
|
{
|
|
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;
|
|
}
|