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, EC_KEY_precompute_mult, 13EC_KEY_generate_key, EC_KEY_check_key, EC_KEY_set_public_key_affine_coordinates, 14EC_KEY_oct2key, EC_KEY_key2buf, EC_KEY_oct2priv, EC_KEY_priv2oct, 15EC_KEY_priv2buf - Functions for creating, destroying and manipulating 16EC_KEY objects 17 18=head1 SYNOPSIS 19 20 #include <openssl/ec.h> 21 22 EC_KEY *EC_KEY_new(void); 23 int EC_KEY_get_flags(const EC_KEY *key); 24 void EC_KEY_set_flags(EC_KEY *key, int flags); 25 void EC_KEY_clear_flags(EC_KEY *key, int flags); 26 EC_KEY *EC_KEY_new_by_curve_name(int nid); 27 void EC_KEY_free(EC_KEY *key); 28 EC_KEY *EC_KEY_copy(EC_KEY *dst, const EC_KEY *src); 29 EC_KEY *EC_KEY_dup(const EC_KEY *src); 30 int EC_KEY_up_ref(EC_KEY *key); 31 ENGINE *EC_KEY_get0_engine(const EC_KEY *eckey); 32 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key); 33 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group); 34 const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key); 35 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *prv); 36 const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key); 37 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub); 38 point_conversion_form_t EC_KEY_get_conv_form(const EC_KEY *key); 39 void EC_KEY_set_conv_form(EC_KEY *eckey, point_conversion_form_t cform); 40 void EC_KEY_set_asn1_flag(EC_KEY *eckey, int asn1_flag); 41 int EC_KEY_precompute_mult(EC_KEY *key, BN_CTX *ctx); 42 int EC_KEY_generate_key(EC_KEY *key); 43 int EC_KEY_check_key(const EC_KEY *key); 44 int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x, BIGNUM *y); 45 const EC_KEY_METHOD *EC_KEY_get_method(const EC_KEY *key); 46 int EC_KEY_set_method(EC_KEY *key, const EC_KEY_METHOD *meth); 47 48 int EC_KEY_oct2key(EC_KEY *eckey, const unsigned char *buf, size_t len, BN_CTX *ctx); 49 size_t EC_KEY_key2buf(const EC_KEY *eckey, point_conversion_form_t form, 50 unsigned char **pbuf, BN_CTX *ctx); 51 52 int EC_KEY_oct2priv(EC_KEY *eckey, const unsigned char *buf, size_t len); 53 size_t EC_KEY_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len); 54 55 size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf); 56 57=head1 DESCRIPTION 58 59An EC_KEY represents a public key and, optionally, the associated private 60key. A new EC_KEY with no associated curve can be constructed by calling 61EC_KEY_new(). The reference count for the newly created EC_KEY is initially 62set to 1. A curve can be associated with the EC_KEY by calling 63EC_KEY_set_group(). 64 65Alternatively a new EC_KEY can be constructed by calling 66EC_KEY_new_by_curve_name() and supplying the nid of the associated curve. See 67L<EC_GROUP_new(3)> for a description of curve names. This function simply 68wraps calls to EC_KEY_new() and EC_GROUP_new_by_curve_name(). 69 70Calling EC_KEY_free() decrements the reference count for the EC_KEY object, 71and if it has dropped to zero then frees the memory associated with it. If 72B<key> is NULL nothing is done. 73 74EC_KEY_copy() copies the contents of the EC_KEY in B<src> into B<dest>. 75 76EC_KEY_dup() creates a new EC_KEY object and copies B<ec_key> into it. 77 78EC_KEY_up_ref() increments the reference count associated with the EC_KEY 79object. 80 81EC_KEY_get0_engine() returns a handle to the ENGINE that has been set for 82this EC_KEY object. 83 84EC_KEY_generate_key() generates a new public and private key for the supplied 85B<eckey> object. B<eckey> must have an EC_GROUP object associated with it 86before calling this function. The private key is a random integer (0 < priv_key 87< order, where I<order> is the order of the EC_GROUP object). The public key is 88an EC_POINT on the curve calculated by multiplying the generator for the 89curve by the private key. 90 91EC_KEY_check_key() performs various sanity checks on the EC_KEY object to 92confirm that it is valid. 93 94EC_KEY_set_public_key_affine_coordinates() sets the public key for B<key> based 95on its affine co-ordinates; i.e., it constructs an EC_POINT object based on 96the supplied B<x> and B<y> values and sets the public key to be this 97EC_POINT. It also performs certain sanity checks on the key to confirm 98that it is valid. 99 100The functions EC_KEY_get0_group(), EC_KEY_set_group(), 101EC_KEY_get0_private_key(), EC_KEY_set_private_key(), EC_KEY_get0_public_key(), 102and EC_KEY_set_public_key() get and set the EC_GROUP object, the private key, 103and the EC_POINT public key for the B<key> respectively. 104 105The functions EC_KEY_get_conv_form() and EC_KEY_set_conv_form() get and set the 106point_conversion_form for the B<key>. For a description of 107point_conversion_forms please see L<EC_POINT_new(3)>. 108 109EC_KEY_set_flags() sets the flags in the B<flags> parameter on the EC_KEY 110object. Any flags that are already set are left set. The flags currently 111defined are EC_FLAG_NON_FIPS_ALLOW and EC_FLAG_FIPS_CHECKED. In 112addition there is the flag EC_FLAG_COFACTOR_ECDH which is specific to ECDH. 113EC_KEY_get_flags() returns the current flags that are set for this EC_KEY. 114EC_KEY_clear_flags() clears the flags indicated by the B<flags> parameter; all 115other flags are left in their existing state. 116 117EC_KEY_set_asn1_flag() sets the asn1_flag on the underlying EC_GROUP object 118(if set). Refer to L<EC_GROUP_copy(3)> for further information on the 119asn1_flag. 120 121EC_KEY_precompute_mult() stores multiples of the underlying EC_GROUP generator 122for faster point multiplication. See also L<EC_POINT_add(3)>. 123 124EC_KEY_oct2key() and EC_KEY_key2buf() are identical to the functions 125EC_POINT_oct2point() and EC_KEY_point2buf() except they use the public key 126EC_POINT in B<eckey>. 127 128EC_KEY_oct2priv() and EC_KEY_priv2oct() convert between the private key 129component of B<eckey> and octet form. The octet form consists of the content 130octets of the B<privateKey> OCTET STRING in an B<ECPrivateKey> ASN.1 structure. 131 132The function EC_KEY_priv2oct() must be supplied with a buffer long enough to 133store the octet form. The return value provides the number of octets stored. 134Calling the function with a NULL buffer will not perform the conversion but 135will just return the required buffer length. 136 137The function EC_KEY_priv2buf() allocates a buffer of suitable length and writes 138an EC_KEY to it in octet format. The allocated buffer is written to B<*pbuf> 139and its length is returned. The caller must free up the allocated buffer with a 140call to OPENSSL_free(). Since the allocated buffer value is written to B<*pbuf> 141the B<pbuf> parameter B<MUST NOT> be B<NULL>. 142 143EC_KEY_priv2buf() converts an EC_KEY private key into an allocated buffer. 144 145=head1 RETURN VALUES 146 147EC_KEY_new(), EC_KEY_new_by_curve_name() and EC_KEY_dup() return a pointer to 148the newly created EC_KEY object, or NULL on error. 149 150EC_KEY_get_flags() returns the flags associated with the EC_KEY object as an 151integer. 152 153EC_KEY_copy() returns a pointer to the destination key, or NULL on error. 154 155EC_KEY_get0_engine() returns a pointer to an ENGINE, or NULL if it wasn't set. 156 157EC_KEY_up_ref(), EC_KEY_set_group(), EC_KEY_set_private_key(), 158EC_KEY_set_public_key(), EC_KEY_precompute_mult(), EC_KEY_generate_key(), 159EC_KEY_check_key(), EC_KEY_set_public_key_affine_coordinates(), 160EC_KEY_oct2key() and EC_KEY_oct2priv() return 1 on success or 0 on error. 161 162EC_KEY_get0_group() returns the EC_GROUP associated with the EC_KEY. 163 164EC_KEY_get0_private_key() returns the private key associated with the EC_KEY. 165 166EC_KEY_get_conv_form() return the point_conversion_form for the EC_KEY. 167 168EC_KEY_key2buf(), EC_KEY_priv2oct() and EC_KEY_priv2buf() return the length 169of the buffer or 0 on error. 170 171=head1 SEE ALSO 172 173L<crypto(7)>, L<EC_GROUP_new(3)>, 174L<EC_GROUP_copy(3)>, L<EC_POINT_new(3)>, 175L<EC_POINT_add(3)>, 176L<EC_GFp_simple_method(3)>, 177L<d2i_ECPKParameters(3)> 178 179=head1 COPYRIGHT 180 181Copyright 2013-2017 The OpenSSL Project Authors. All Rights Reserved. 182 183Licensed under the OpenSSL license (the "License"). You may not use 184this file except in compliance with the License. You can obtain a copy 185in the file LICENSE in the source distribution or at 186L<https://www.openssl.org/source/license.html>. 187 188=cut 189