1=pod 2 3=head1 NAME 4 5EC_KEY_get_method, EC_KEY_set_method, 6EC_KEY_new, EC_KEY_get_flags, EC_KEY_set_flags, EC_KEY_clear_flags, 7EC_KEY_new_by_curve_name, EC_KEY_free, EC_KEY_copy, EC_KEY_dup, EC_KEY_up_ref, 8EC_KEY_get0_engine, 9EC_KEY_get0_group, EC_KEY_set_group, EC_KEY_get0_private_key, 10EC_KEY_set_private_key, EC_KEY_get0_public_key, EC_KEY_set_public_key, 11EC_KEY_get_conv_form, 12EC_KEY_set_conv_form, EC_KEY_set_asn1_flag, 13EC_KEY_decoded_from_explicit_params, EC_KEY_precompute_mult, 14EC_KEY_generate_key, EC_KEY_check_key, EC_KEY_set_public_key_affine_coordinates, 15EC_KEY_oct2key, EC_KEY_key2buf, EC_KEY_oct2priv, EC_KEY_priv2oct, 16EC_KEY_priv2buf - Functions for creating, destroying and manipulating 17EC_KEY objects 18 19=head1 SYNOPSIS 20 21 #include <openssl/ec.h> 22 23 EC_KEY *EC_KEY_new(void); 24 int EC_KEY_get_flags(const EC_KEY *key); 25 void EC_KEY_set_flags(EC_KEY *key, int flags); 26 void EC_KEY_clear_flags(EC_KEY *key, int flags); 27 EC_KEY *EC_KEY_new_by_curve_name(int nid); 28 void EC_KEY_free(EC_KEY *key); 29 EC_KEY *EC_KEY_copy(EC_KEY *dst, const EC_KEY *src); 30 EC_KEY *EC_KEY_dup(const EC_KEY *src); 31 int EC_KEY_up_ref(EC_KEY *key); 32 ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey); 33 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key); 34 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group); 35 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key); 36 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *prv); 37 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key); 38 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub); 39 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key); 40 void EC_KEY_set_conv_form(EC_KEY *eckey, point_conversion_form_t cform); 41 void EC_KEY_set_asn1_flag(EC_KEY *eckey, int asn1_flag); 42 int EC_KEY_decoded_from_explicit_params(const EC_KEY *key); 43 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx); 44 int EC_KEY_generate_key(EC_KEY *key); 45 int EC_KEY_check_key(const EC_KEY *key); 46 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, BIGNUM *y); 47 const EC_KEY_METHOD *EC_KEY_get_method(const EC_KEY *key); 48 int EC_KEY_set_method(EC_KEY *key, const EC_KEY_METHOD *meth); 49 50 int EC_KEY_oct2key(EC_KEY *eckey, const unsigned char *buf, size_t len, BN_CTX *ctx); 51 size_t EC_KEY_key2buf(const EC_KEY *eckey, point_conversion_form_t form, 52 unsigned char **pbuf, BN_CTX *ctx); 53 54 int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len); 55 size_t EC_KEY_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len); 56 57 size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf); 58 59=head1 DESCRIPTION 60 61An EC_KEY represents a public key and, optionally, the associated private 62key. A new EC_KEY with no associated curve can be constructed by calling 63EC_KEY_new(). The reference count for the newly created EC_KEY is initially 64set to 1. A curve can be associated with the EC_KEY by calling 65EC_KEY_set_group(). 66 67Alternatively a new EC_KEY can be constructed by calling 68EC_KEY_new_by_curve_name() and supplying the nid of the associated curve. See 69L<EC_GROUP_new(3)> for a description of curve names. This function simply 70wraps calls to EC_KEY_new() and EC_GROUP_new_by_curve_name(). 71 72Calling EC_KEY_free() decrements the reference count for the EC_KEY object, 73and if it has dropped to zero then frees the memory associated with it. If 74B<key> is NULL nothing is done. 75 76EC_KEY_copy() copies the contents of the EC_KEY in B<src> into B<dest>. 77 78EC_KEY_dup() creates a new EC_KEY object and copies B<ec_key> into it. 79 80EC_KEY_up_ref() increments the reference count associated with the EC_KEY 81object. 82 83EC_KEY_get0_engine() returns a handle to the ENGINE that has been set for 84this EC_KEY object. 85 86EC_KEY_generate_key() generates a new public and private key for the supplied 87B<eckey> object. B<eckey> must have an EC_GROUP object associated with it 88before calling this function. The private key is a random integer (0 < priv_key 89< order, where I<order> is the order of the EC_GROUP object). The public key is 90an EC_POINT on the curve calculated by multiplying the generator for the 91curve by the private key. 92 93EC_KEY_check_key() performs various sanity checks on the EC_KEY object to 94confirm that it is valid. 95 96EC_KEY_set_public_key_affine_coordinates() sets the public key for B<key> based 97on its affine co-ordinates; i.e., it constructs an EC_POINT object based on 98the supplied B<x> and B<y> values and sets the public key to be this 99EC_POINT. It also performs certain sanity checks on the key to confirm 100that it is valid. 101 102The functions EC_KEY_get0_group(), EC_KEY_set_group(), 103EC_KEY_get0_private_key(), EC_KEY_set_private_key(), EC_KEY_get0_public_key(), 104and EC_KEY_set_public_key() get and set the EC_GROUP object, the private key, 105and the EC_POINT public key for the B<key> respectively. 106 107The functions EC_KEY_get_conv_form() and EC_KEY_set_conv_form() get and set the 108point_conversion_form for the B<key>. For a description of 109point_conversion_forms please see L<EC_POINT_new(3)>. 110 111EC_KEY_set_flags() sets the flags in the B<flags> parameter on the EC_KEY 112object. Any flags that are already set are left set. The flags currently 113defined are EC_FLAG_NON_FIPS_ALLOW and EC_FLAG_FIPS_CHECKED. In 114addition there is the flag EC_FLAG_COFACTOR_ECDH which is specific to ECDH. 115EC_KEY_get_flags() returns the current flags that are set for this EC_KEY. 116EC_KEY_clear_flags() clears the flags indicated by the B<flags> parameter; all 117other flags are left in their existing state. 118 119EC_KEY_set_asn1_flag() sets the asn1_flag on the underlying EC_GROUP object 120(if set). Refer to L<EC_GROUP_copy(3)> for further information on the 121asn1_flag. 122 123EC_KEY_decoded_from_explicit_params() returns 1 if the group of the I<key> was 124decoded from data with explicitly encoded group parameters, -1 if the I<key> 125is NULL or the group parameters are missing, and 0 otherwise. 126 127EC_KEY_precompute_mult() stores multiples of the underlying EC_GROUP generator 128for faster point multiplication. See also L<EC_POINT_add(3)>. 129 130EC_KEY_oct2key() and EC_KEY_key2buf() are identical to the functions 131EC_POINT_oct2point() and EC_POINT_point2buf() except they use the public key 132EC_POINT in B<eckey>. 133 134EC_KEY_oct2priv() and EC_KEY_priv2oct() convert between the private key 135component of B<eckey> and octet form. The octet form consists of the content 136octets of the B<privateKey> OCTET STRING in an B<ECPrivateKey> ASN.1 structure. 137 138The function EC_KEY_priv2oct() must be supplied with a buffer long enough to 139store the octet form. The return value provides the number of octets stored. 140Calling the function with a NULL buffer will not perform the conversion but 141will just return the required buffer length. 142 143The function EC_KEY_priv2buf() allocates a buffer of suitable length and writes 144an EC_KEY to it in octet format. The allocated buffer is written to B<*pbuf> 145and its length is returned. The caller must free up the allocated buffer with a 146call to OPENSSL_free(). Since the allocated buffer value is written to B<*pbuf> 147the B<pbuf> parameter B<MUST NOT> be B<NULL>. 148 149EC_KEY_priv2buf() converts an EC_KEY private key into an allocated buffer. 150 151=head1 RETURN VALUES 152 153EC_KEY_new(), EC_KEY_new_by_curve_name() and EC_KEY_dup() return a pointer to 154the newly created EC_KEY object, or NULL on error. 155 156EC_KEY_get_flags() returns the flags associated with the EC_KEY object as an 157integer. 158 159EC_KEY_copy() returns a pointer to the destination key, or NULL on error. 160 161EC_KEY_get0_engine() returns a pointer to an ENGINE, or NULL if it wasn't set. 162 163EC_KEY_up_ref(), EC_KEY_set_group(), EC_KEY_set_private_key(), 164EC_KEY_set_public_key(), EC_KEY_precompute_mult(), EC_KEY_generate_key(), 165EC_KEY_check_key(), EC_KEY_set_public_key_affine_coordinates(), 166EC_KEY_oct2key() and EC_KEY_oct2priv() return 1 on success or 0 on error. 167 168EC_KEY_get0_group() returns the EC_GROUP associated with the EC_KEY. 169 170EC_KEY_get0_private_key() returns the private key associated with the EC_KEY. 171 172EC_KEY_get_conv_form() return the point_conversion_form for the EC_KEY. 173 174EC_KEY_key2buf(), EC_KEY_priv2oct() and EC_KEY_priv2buf() return the length 175of the buffer or 0 on error. 176 177=head1 SEE ALSO 178 179L<crypto(7)>, L<EC_GROUP_new(3)>, 180L<EC_GROUP_copy(3)>, L<EC_POINT_new(3)>, 181L<EC_POINT_add(3)>, 182L<EC_GFp_simple_method(3)>, 183L<d2i_ECPKParameters(3)> 184 185=head1 COPYRIGHT 186 187Copyright 2013-2020 The OpenSSL Project Authors. All Rights Reserved. 188 189Licensed under the OpenSSL license (the "License"). You may not use 190this file except in compliance with the License. You can obtain a copy 191in the file LICENSE in the source distribution or at 192L<https://www.openssl.org/source/license.html>. 193 194=cut 195