generation method, but may be required for assurance purposes when receiving
keys from a third party.
+The EVP_PKEY_pairwise_check() and EVP_PKEY_private_check() might not be bounded
+by any key size limits as private keys are not expected to be supplied by
+attackers. For that reason they might take an unbounded time if run on
+arbitrarily large keys.
+
=head1 RETURN VALUES
All functions return 1 for success or others for failure.