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git.ipfire.org Git - thirdparty/openssl.git/blob - crypto/ec/ec_cvt.c
2 * Copyright 2001-2021 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
5 * Licensed under the Apache License 2.0 (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
12 * ECDSA low level APIs are deprecated for public use, but still ok for
15 #include "internal/deprecated.h"
17 #include <openssl/err.h>
18 #include "crypto/bn.h"
21 EC_GROUP
*EC_GROUP_new_curve_GFp(const BIGNUM
*p
, const BIGNUM
*a
,
22 const BIGNUM
*b
, BN_CTX
*ctx
)
24 const EC_METHOD
*meth
;
27 #if defined(OPENSSL_BN_ASM_MONT)
29 * This might appear controversial, but the fact is that generic
30 * prime method was observed to deliver better performance even
31 * for NIST primes on a range of platforms, e.g.: 60%-15%
32 * improvement on IA-64, ~25% on ARM, 30%-90% on P4, 20%-25%
33 * in 32-bit build and 35%--12% in 64-bit build on Core2...
34 * Coefficients are relative to optimized bn_nist.c for most
35 * intensive ECDSA verify and ECDH operations for 192- and 521-
36 * bit keys respectively. Choice of these boundary values is
37 * arguable, because the dependency of improvement coefficient
38 * from key length is not a "monotone" curve. For example while
39 * 571-bit result is 23% on ARM, 384-bit one is -1%. But it's
40 * generally faster, sometimes "respectfully" faster, sometimes
41 * "tolerably" slower... What effectively happens is that loop
42 * with bn_mul_add_words is put against bn_mul_mont, and the
43 * latter "wins" on short vectors. Correct solution should be
44 * implementing dedicated NxN multiplication subroutines for
45 * small N. But till it materializes, let's stick to generic
49 meth
= EC_GFp_mont_method();
51 if (BN_nist_mod_func(p
))
52 meth
= EC_GFp_nist_method();
54 meth
= EC_GFp_mont_method();
57 ret
= ossl_ec_group_new_ex(ossl_bn_get_libctx(ctx
), NULL
, meth
);
61 if (!EC_GROUP_set_curve(ret
, p
, a
, b
, ctx
)) {
69 #ifndef OPENSSL_NO_EC2M
70 EC_GROUP
*EC_GROUP_new_curve_GF2m(const BIGNUM
*p
, const BIGNUM
*a
,
71 const BIGNUM
*b
, BN_CTX
*ctx
)
73 const EC_METHOD
*meth
;
76 meth
= EC_GF2m_simple_method();
78 ret
= ossl_ec_group_new_ex(ossl_bn_get_libctx(ctx
), NULL
, meth
);
82 if (!EC_GROUP_set_curve(ret
, p
, a
, b
, ctx
)) {