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