1=pod 2 3=head1 NAME 4 5i2d_ECPrivateKey, d2i_ECPrivate_key - Encode and decode functions for saving and 6reading EC_KEY structures 7 8=head1 SYNOPSIS 9 10 #include <openssl/ec.h> 11 12 EC_KEY *d2i_ECPrivateKey(EC_KEY **key, const unsigned char **in, long len); 13 int i2d_ECPrivateKey(EC_KEY *key, unsigned char **out); 14 15 unsigned int EC_KEY_get_enc_flags(const EC_KEY *key); 16 void EC_KEY_set_enc_flags(EC_KEY *eckey, unsigned int flags); 17 18=head1 DESCRIPTION 19 20The ECPrivateKey encode and decode routines encode and parse an 21B<EC_KEY> structure into a binary format (ASN.1 DER) and back again. 22 23These functions are similar to the d2i_X509() functions, and you should refer to 24that page for a detailed description (see L<d2i_X509(3)|d2i_X509(3)>). 25 26The format of the external representation of the public key written by 27i2d_ECPrivateKey (such as whether it is stored in a compressed form or not) is 28described by the point_conversion_form. See L<EC_GROUP_copy(3)|EC_GROUP_copy(3)> 29for a description of point_conversion_form. 30 31When reading a private key encoded without an associated public key (e.g. if 32EC_PKEY_NO_PUBKEY has been used - see below), then d2i_ECPrivateKey generates 33the missing public key automatically. Private keys encoded without parameters 34(e.g. if EC_PKEY_NO_PARAMETERS has been used - see below) cannot be loaded using 35d2i_ECPrivateKey. 36 37The functions EC_KEY_get_enc_flags and EC_KEY_set_enc_flags get and set the 38value of the encoding flags for the B<key>. There are two encoding flags 39currently defined - EC_PKEY_NO_PARAMETERS and EC_PKEY_NO_PUBKEY. These flags 40define the behaviour of how the B<key> is converted into ASN1 in a call to 41i2d_ECPrivateKey. If EC_PKEY_NO_PARAMETERS is set then the public parameters for 42the curve are not encoded along with the private key. If EC_PKEY_NO_PUBKEY is 43set then the public key is not encoded along with the private key. 44 45=head1 RETURN VALUES 46 47d2i_ECPrivateKey() returns a valid B<EC_KEY> structure or B<NULL> if an error 48occurs. The error code that can be obtained by 49L<ERR_get_error(3)|ERR_get_error(3)>. 50 51i2d_ECPrivateKey() returns the number of bytes successfully encoded or a 52negative value if an error occurs. The error code can be obtained by 53L<ERR_get_error(3)|ERR_get_error(3)>. 54 55EC_KEY_get_enc_flags returns the value of the current encoding flags for the 56EC_KEY. 57 58=head1 SEE ALSO 59 60L<crypto(3)|crypto(3)>, L<ec(3)|ec(3)>, L<EC_GROUP_new(3)|EC_GROUP_new(3)>, 61L<EC_GROUP_copy(3)|EC_GROUP_copy(3)>, L<EC_POINT_new(3)|EC_POINT_new(3)>, 62L<EC_POINT_add(3)|EC_POINT_add(3)>, 63L<EC_GFp_simple_method(3)|EC_GFp_simple_method(3)>, 64L<d2i_ECPKParameters(3)|d2i_ECPKParameters(3)>, 65L<d2i_ECPrivateKey(3)|d2i_ECPrivateKey(3)> 66 67=cut 68