=pod

=head1 NAME

EVP_PKEY_check, EVP_PKEY_param_check, EVP_PKEY_public_check,
EVP_PKEY_private_check, EVP_PKEY_pairwise_check
- key and parameter validation functions

=head1 SYNOPSIS

 #include <openssl/evp.h>

 int EVP_PKEY_check(EVP_PKEY_CTX *ctx);
 int EVP_PKEY_param_check(EVP_PKEY_CTX *ctx);
 int EVP_PKEY_public_check(EVP_PKEY_CTX *ctx);
 int EVP_PKEY_private_check(EVP_PKEY_CTX *ctx);
 int EVP_PKEY_pairwise_check(EVP_PKEY_CTX *ctx);

=head1 DESCRIPTION

EVP_PKEY_param_check() validates the parameters component of the key
given by B<ctx>.

EVP_PKEY_public_check() validates the public component of the key given by B<ctx>.

EVP_PKEY_private_check() validates the private component of the key given by B<ctx>.

EVP_PKEY_pairwise_check() validates that the public and private components have
the correct mathematical relationship to each other for the key given by B<ctx>.

EVP_PKEY_check() validates all components of a key given by B<ctx>.

=head1 NOTES

Refer to SP800-56A and SP800-56B for rules relating to when these functions
should be called during key establishment.
It is not necessary to call these functions after locally calling an approved key
generation method, but may be required for assurance purposes when receiving
keys from a third party.

=head1 RETURN VALUES

All functions return 1 for success or others for failure.
They return -2 if the operation is not supported for the specific algorithm.

=head1 SEE ALSO

L<EVP_PKEY_CTX_new(3)>,
L<EVP_PKEY_fromdata(3)>,

=head1 HISTORY

EVP_PKEY_check(), EVP_PKEY_public_check() and EVP_PKEY_param_check() were added
in OpenSSL 1.1.1.

EVP_PKEY_private_check() and EVP_PKEY_pairwise_check() were added
in OpenSSL 3.0.

=head1 COPYRIGHT

Copyright 2006-2020 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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