181 lines
6.3 KiB
C
181 lines
6.3 KiB
C
/* crypto/ec/ec_cvt.c */
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/*
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* Originally written by Bodo Moeller for the OpenSSL project.
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*/
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/* ====================================================================
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* Copyright (c) 1998-2002 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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/* ====================================================================
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* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
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*
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* Portions of the attached software ("Contribution") are developed by
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* SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
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*
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* The Contribution is licensed pursuant to the OpenSSL open source
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* license provided above.
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*
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* The elliptic curve binary polynomial software is originally written by
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* Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems Laboratories.
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*
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*/
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#include <openssl/err.h>
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#include "ec_lcl.h"
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#ifdef OPENSSL_FIPS
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# include <openssl/fips.h>
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#endif
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EC_GROUP *EC_GROUP_new_curve_GFp(const BIGNUM *p, const BIGNUM *a,
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const BIGNUM *b, BN_CTX *ctx)
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{
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const EC_METHOD *meth;
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EC_GROUP *ret;
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#ifdef OPENSSL_FIPS
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if (FIPS_mode())
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return FIPS_ec_group_new_curve_gfp(p, a, b, ctx);
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#endif
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#if defined(OPENSSL_BN_ASM_MONT)
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/*
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* This might appear controversial, but the fact is that generic
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* prime method was observed to deliver better performance even
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* for NIST primes on a range of platforms, e.g.: 60%-15%
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* improvement on IA-64, ~25% on ARM, 30%-90% on P4, 20%-25%
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* in 32-bit build and 35%--12% in 64-bit build on Core2...
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* Coefficients are relative to optimized bn_nist.c for most
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* intensive ECDSA verify and ECDH operations for 192- and 521-
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* bit keys respectively. Choice of these boundary values is
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* arguable, because the dependency of improvement coefficient
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* from key length is not a "monotone" curve. For example while
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* 571-bit result is 23% on ARM, 384-bit one is -1%. But it's
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* generally faster, sometimes "respectfully" faster, sometimes
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* "tolerably" slower... What effectively happens is that loop
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* with bn_mul_add_words is put against bn_mul_mont, and the
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* latter "wins" on short vectors. Correct solution should be
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* implementing dedicated NxN multiplication subroutines for
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* small N. But till it materializes, let's stick to generic
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* prime method...
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* <appro>
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*/
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meth = EC_GFp_mont_method();
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#else
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meth = EC_GFp_nist_method();
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#endif
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ret = EC_GROUP_new(meth);
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if (ret == NULL)
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return NULL;
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if (!EC_GROUP_set_curve_GFp(ret, p, a, b, ctx)) {
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unsigned long err;
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err = ERR_peek_last_error();
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if (!(ERR_GET_LIB(err) == ERR_LIB_EC &&
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((ERR_GET_REASON(err) == EC_R_NOT_A_NIST_PRIME) ||
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(ERR_GET_REASON(err) == EC_R_NOT_A_SUPPORTED_NIST_PRIME)))) {
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/* real error */
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EC_GROUP_clear_free(ret);
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return NULL;
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}
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/*
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* not an actual error, we just cannot use EC_GFp_nist_method
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*/
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ERR_clear_error();
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EC_GROUP_clear_free(ret);
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meth = EC_GFp_mont_method();
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ret = EC_GROUP_new(meth);
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if (ret == NULL)
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return NULL;
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if (!EC_GROUP_set_curve_GFp(ret, p, a, b, ctx)) {
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EC_GROUP_clear_free(ret);
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return NULL;
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}
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}
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return ret;
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}
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#ifndef OPENSSL_NO_EC2M
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EC_GROUP *EC_GROUP_new_curve_GF2m(const BIGNUM *p, const BIGNUM *a,
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const BIGNUM *b, BN_CTX *ctx)
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{
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const EC_METHOD *meth;
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EC_GROUP *ret;
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# ifdef OPENSSL_FIPS
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if (FIPS_mode())
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return FIPS_ec_group_new_curve_gf2m(p, a, b, ctx);
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# endif
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meth = EC_GF2m_simple_method();
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ret = EC_GROUP_new(meth);
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if (ret == NULL)
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return NULL;
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if (!EC_GROUP_set_curve_GF2m(ret, p, a, b, ctx)) {
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EC_GROUP_clear_free(ret);
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return NULL;
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}
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return ret;
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}
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#endif
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