=pod

=head1 NAME

EVP_PKEY_asn1_find,
EVP_PKEY_asn1_find_str,
EVP_PKEY_asn1_get_count,
EVP_PKEY_asn1_get0,
EVP_PKEY_asn1_get0_info
- enumerate public key ASN.1 methods

=head1 SYNOPSIS

 #include <openssl/evp.h>

 int EVP_PKEY_asn1_get_count(void);
 const EVP_PKEY_ASN1_METHOD *EVP_PKEY_asn1_get0(int idx);
 const EVP_PKEY_ASN1_METHOD *EVP_PKEY_asn1_find(ENGINE **pe, int type);
 const EVP_PKEY_ASN1_METHOD *EVP_PKEY_asn1_find_str(ENGINE **pe,
                                                    const char *str, int len);
 int EVP_PKEY_asn1_get0_info(int *ppkey_id, int *pkey_base_id,
                             int *ppkey_flags, const char **pinfo,
                             const char **ppem_str,
                             const EVP_PKEY_ASN1_METHOD *ameth);

=head1 DESCRIPTION

EVP_PKEY_asn1_count() returns a count of the number of public key
ASN.1 methods available: it includes standard methods and any methods
added by the application.

EVP_PKEY_asn1_get0() returns the public key ASN.1 method B<idx>.
The value of B<idx> must be between zero and EVP_PKEY_asn1_get_count()
- 1.

EVP_PKEY_asn1_find() looks up the B<EVP_PKEY_ASN1_METHOD> with NID
B<type>.
If B<pe> isn't B<NULL>, then it will look up an engine implementing a
B<EVP_PKEY_ASN1_METHOD> for the NID B<type> and return that instead,
and also set B<*pe> to point at the engine that implements it.

EVP_PKEY_asn1_find_str() looks up the B<EVP_PKEY_ASN1_METHOD> with PEM
type string B<str>.
Just like EVP_PKEY_asn1_find(), if B<pe> isn't B<NULL>, then it will
look up an engine implementing a B<EVP_PKEY_ASN1_METHOD> for the NID
B<type> and return that instead, and also set B<*pe> to point at the
engine that implements it.

EVP_PKEY_asn1_get0_info() returns the public key ID, base public key
ID (both NIDs), any flags, the method description and PEM type string
associated with the public key ASN.1 method B<*ameth>.

EVP_PKEY_asn1_count(), EVP_PKEY_asn1_get0(), EVP_PKEY_asn1_find() and
EVP_PKEY_asn1_find_str() are not thread safe, but as long as all
B<EVP_PKEY_ASN1_METHOD> objects are added before the application gets
threaded, using them is safe.  See L<EVP_PKEY_asn1_add0(3)>.

=head1 RETURN VALUES

EVP_PKEY_asn1_count() returns the number of available public key methods.

EVP_PKEY_asn1_get0() return a public key method or B<NULL> if B<idx> is
out of range.

EVP_PKEY_asn1_get0_info() returns 0 on failure, 1 on success.

=head1 SEE ALSO

L<EVP_PKEY_asn1_new(3)>, L<EVP_PKEY_asn1_add0(3)>

=head1 COPYRIGHT

Copyright 2017-2019 The OpenSSL Project Authors. 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
L<https://www.openssl.org/source/license.html>.

=cut
