/* * Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved. * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved * * Licensed under the OpenSSL license (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ #include <openssl/err.h> #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... * <appro> */ meth = EC_GFp_mont_method(); #else if (BN_nist_mod_func(p)) meth = EC_GFp_nist_method(); else meth = EC_GFp_mont_method(); #endif 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