| =pod |
| |
| =head1 NAME |
| |
| EVP_SIGNATURE_fetch, EVP_SIGNATURE_free, EVP_SIGNATURE_up_ref, |
| EVP_SIGNATURE_provider |
| - Functions to manage EVP_SIGNATURE algorithm objects |
| |
| =head1 SYNOPSIS |
| |
| #include <openssl/evp.h> |
| |
| EVP_SIGNATURE *EVP_SIGNATURE_fetch(OPENSSL_CTX *ctx, const char *algorithm, |
| const char *properties); |
| void EVP_SIGNATURE_free(EVP_SIGNATURE *signature); |
| int EVP_SIGNATURE_up_ref(EVP_SIGNATURE *signature); |
| OSSL_PROVIDER *EVP_SIGNATURE_provider(const EVP_SIGNATURE *signature); |
| |
| =head1 DESCRIPTION |
| |
| EVP_SIGNATURE_fetch() fetches the implementation for the given |
| B<algorithm> from any provider offering it, within the criteria given |
| by the B<properties>. |
| The algorithm will be one offering functions for performing signature related |
| tasks such as signing and verifying. |
| See L<provider(7)/Fetching algorithms> for further information. |
| |
| The returned value must eventually be freed with EVP_SIGNATURE_free(). |
| |
| EVP_SIGNATURE_free() decrements the reference count for the B<EVP_SIGNATURE> |
| structure. Typically this structure will have been obtained from an earlier call |
| to EVP_SIGNATURE_fetch(). If the reference count drops to 0 then the |
| structure is freed. |
| |
| EVP_SIGNATURE_up_ref() increments the reference count for an B<EVP_SIGNATURE> |
| structure. |
| |
| EVP_SIGNATURE_provider() returns the provider that I<signature> was fetched from. |
| |
| =head1 RETURN VALUES |
| |
| EVP_SIGNATURE_fetch() returns a pointer to an B<EVP_SIGNATURE> for success |
| or B<NULL> for failure. |
| |
| EVP_SIGNATURE_up_ref() returns 1 for success or 0 otherwise. |
| |
| =head1 SEE ALSO |
| |
| L<provider(7)/Fetching algorithms>, L<OSSL_PROVIDER(3)> |
| |
| =head1 HISTORY |
| |
| The functions described here were added in OpenSSL 3.0. |
| |
| =head1 COPYRIGHT |
| |
| Copyright 2019 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>. |
| |
| =cut |
