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=head1 NAME

OSSL_STORE_expect - Specify what object type is expected

=head1 SYNOPSIS

 #include <openssl/store.h>

 int OSSL_STORE_expect(OSSL_STORE_CTX *ctx, int expected_type);

=head1 DESCRIPTION

OSSL_STORE_expect() helps applications filter what OSSL_STORE_load() returns
by specifying a B<OSSL_STORE_INFO> type.
For example, if C<file:/foo/bar/store.pem> contains several different objects
and only the certificates are interesting, the application can simply say
that it expects the type B<OSSL_STORE_INFO_CERT>.
All known object types (see L<OSSL_STORE_INFO(3)/SUPPORTED OBJECTS>)
except for B<OSSL_STORE_INFO_NAME> are supported.

OSSL_STORE_expect() I<must> be called before the first OSSL_STORE_load()
of a given session, or it 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.

=head1 SEE ALSO

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

=head1 HISTORY

OSSL_STORE_expect()
was added to OpenSSL 1.1.1.

=head1 COPYRIGHT

Copyright 2018 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>.

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