=pod

=head1 NAME

OSSL_STORE_expect,
OSSL_STORE_supports_search,
OSSL_STORE_find
- Specify what object type is expected

=head1 SYNOPSIS

 #include <openssl/store.h>

 int OSSL_STORE_expect(OSSL_STORE_CTX *ctx, int expected_type);

 int OSSL_STORE_supports_search(OSSL_STORE_CTX *ctx, int criterion_type);

 int OSSL_STORE_find(OSSL_STORE_CTX *ctx, OSSL_STORE_SEARCH *search);

=head1 DESCRIPTION

OSSL_STORE_expect() helps applications filter what OSSL_STORE_load() returns
by specifying a B<OSSL_STORE_INFO> type.
By default, no expectations on the types of objects to be loaded are made.
I<expected_type> may be 0 to indicate explicitly that no expectation is made,
or it may be any of the known object types (see
L<OSSL_STORE_INFO(3)/SUPPORTED OBJECTS>) except for B<OSSL_STORE_INFO_NAME>.
For example, if C<file:/foo/bar/store.pem> contains several objects of different
type and only certificates are interesting, the application can simply say
that it expects the type B<OSSL_STORE_INFO_CERT>.

OSSL_STORE_find() helps applications specify a criterion for a more fine
grained search of objects.

OSSL_STORE_supports_search() checks if the loader of the given OSSL_STORE
context supports the given search type.
See L<OSSL_STORE_SEARCH(3)/SUPPORTED CRITERION TYPES> for information on the
supported search criterion types.

OSSL_STORE_expect() and OSSL_STORE_find I<must> be called before the first
OSSL_STORE_load() of a given session, or they will fail.

=head1 NOTES

If a more elaborate filter is required by the application, a better choice
would be to use a post-processing function.
See L<OSSL_STORE_open(3)> for more information.

However, some loaders may take advantage of the knowledge of an expected type
to make object retrieval more efficient, so if a single type is expected, this
method is usually preferable.

=head1 RETURN VALUES

OSSL_STORE_expect() returns 1 on success, or 0 on failure.

OSSL_STORE_supports_search() returns 1 if the criterion is supported, or 0
otherwise.

OSSL_STORE_find() returns 1 on success, or 0 on failure.

=head1 SEE ALSO

L<ossl_store(7)>, L<OSSL_STORE_INFO(3)>, L<OSSL_STORE_SEARCH(3)>,
L<OSSL_STORE_load(3)>

=head1 HISTORY

OSSL_STORE_expect(), OSSL_STORE_supports_search() and OSSL_STORE_find()
were added in OpenSSL 1.1.1.

=head1 COPYRIGHT

Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (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>.

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