openssl/crypto/engine/engine_openssl.c

175 lines
6.1 KiB
C

/* crypto/engine/engine_openssl.c */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
* project 2000.
*/
/* ====================================================================
* Copyright (c) 1999 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
* licensing@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 <openssl/crypto.h>
#include "cryptlib.h"
#include "engine_int.h"
#include <openssl/engine.h>
#include <openssl/dso.h>
#include <openssl/rsa.h>
#include <openssl/dsa.h>
#include <openssl/dh.h>
#include <openssl/rand.h>
#include <openssl/bn.h>
/* This is the only function we need to implement as OpenSSL
* doesn't have a native CRT mod_exp. Perhaps this should be
* BN_mod_exp_crt and moved into crypto/bn/ ?? ... dunno. */
static int openssl_mod_exp_crt(BIGNUM *r, BIGNUM *a, const BIGNUM *p,
const BIGNUM *q, const BIGNUM *dmp1, const BIGNUM *dmq1,
const BIGNUM *iqmp, BN_CTX *ctx);
/* The ENGINE structure that can be pointed to. */
static ENGINE engine_openssl =
{
"openssl",
"Software default engine support",
NULL,
NULL,
NULL, /* these methods are "stolen" in ENGINE_openssl() */
NULL,
NULL,
openssl_mod_exp_crt,
NULL, /* no init() */
NULL, /* no finish() */
NULL, /* no ctrl() */
NULL, /* no load_privkey() */
NULL, /* no load_pubkey() */
0, /* no flags */
0, 0, /* no references. */
NULL, NULL /* unlinked */
};
/* As this is only ever called once, there's no need for locking
* (indeed - the lock will already be held by our caller!!!) */
ENGINE *ENGINE_openssl()
{
/* We need to populate our structure with the software pointers
* that we want to steal. */
engine_openssl.rsa_meth = RSA_get_default_openssl_method();
engine_openssl.dsa_meth = DSA_get_default_openssl_method();
engine_openssl.dh_meth = DH_get_default_openssl_method();
engine_openssl.rand_meth = RAND_SSLeay();
engine_openssl.bn_mod_exp = BN_mod_exp;
return &engine_openssl;
}
/* Chinese Remainder Theorem, taken and adapted from rsa_eay.c */
static int openssl_mod_exp_crt(BIGNUM *r, BIGNUM *a, const BIGNUM *p,
const BIGNUM *q, const BIGNUM *dmp1,
const BIGNUM *dmq1, const BIGNUM *iqmp, BN_CTX *ctx)
{
BIGNUM r1,m1;
int ret=0;
BN_CTX *bn_ctx;
BIGNUM *temp_bn = NULL;
if (ctx)
bn_ctx = ctx;
else
if ((bn_ctx=BN_CTX_new()) == NULL) goto err;
BN_init(&m1);
BN_init(&r1);
/* BN_mul() cannot accept const BIGNUMs so I use the BN_CTX
* to duplicate what I need. <sigh> */
if ((temp_bn = BN_CTX_get(bn_ctx)) == NULL) goto err;
if (!BN_copy(temp_bn, iqmp)) goto err;
if (!BN_mod(&r1, a, q, bn_ctx)) goto err;
if (!engine_openssl.bn_mod_exp(&m1, &r1, dmq1, q, bn_ctx))
goto err;
if (!BN_mod(&r1, a, p, bn_ctx)) goto err;
if (!engine_openssl.bn_mod_exp(r, &r1, dmp1, p, bn_ctx))
goto err;
if (!BN_sub(r, r, &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 (r->neg)
if (!BN_add(r, r, p)) goto err;
if (!BN_mul(&r1, r, temp_bn, bn_ctx)) goto err;
if (!BN_mod(r, &r1, p, bn_ctx)) goto err;
/* If p < q it is occasionally possible for the correction of
* adding 'p' if r 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 (r->neg)
if (!BN_add(r, r, p)) goto err;
/* Again, BN_mul() will need non-const values. */
if (!BN_copy(temp_bn, q)) goto err;
if (!BN_mul(&r1, r, temp_bn, bn_ctx)) goto err;
if (!BN_add(r, &r1, &m1)) goto err;
ret=1;
err:
BN_clear_free(&m1);
BN_clear_free(&r1);
if (temp_bn)
bn_ctx->tos--;
if (!ctx)
BN_CTX_free(bn_ctx);
return(ret);
}