OSSL_STORE_expect(3)

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

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);

DESCRIPTION
OSSL_STORE_expect() helps applications filter what OSSL_STORE_load() returns by specifying a OSSL_STORE_INFO type. By default, no expectations on the types of objects to be loaded are made. expected_type may be 0 to indicate explicitly that no expectation is made, or it may be any of the known object types (see "SUPPORTED OBJECTS" in OSSL_STORE_INFO(3)) except for OSSL_STORE_INFO_NAME. For example, if "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 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 "SUPPORTED CRITERION TYPES" in OSSL_STORE_SEARCH(3) for information on the supported search criterion types.

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

NOTES
If a more elaborate filter is required by the application, a better choice would be to use a post-processing function. See 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.

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.

SEE ALSO
ossl_store(7), OSSL_STORE_INFO(3), OSSL_STORE_SEARCH(3), OSSL_STORE_load(3)

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

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 <https://www.openssl.org/source/license.html>.