+=pod
+
+=head1 NAME
+
+EVP_PKEY_supports_digest_nid - indicate support for signature digest
+
+=head1 SYNOPSIS
+
+ #include <openssl/evp.h>
+ int EVP_PKEY_supports_digest_nid(EVP_PKEY *pkey, int nid);
+
+=head1 DESCRIPTION
+
+The EVP_PKEY_supports_digest_nid() function queries whether the message digest
+NID B<nid> is supported for public key signature operations associated with key
+B<pkey>.
+
+=head1 NOTES
+
+If the EVP_PKEY implementation does not explicitly support this method, but
+L<EVP_PKEY_get_default_digest_nid(3)> returns a mandatory digest result, then
+only that mandatory digest will be supported.
+
+=head1 RETURN VALUES
+
+The EVP_PKEY_supports_digest_nid() function returns 1 if the message digest
+algorithm identified by B<nid> can be used for public key signature operations
+associated with key B<pkey> and 0 if it cannot be used. It returns a negative
+value for failure. In particular a return value of -2 indicates the query
+operation is not supported by the public key algorithm.
+
+=head1 SEE ALSO
+
+L<EVP_PKEY_CTX_new(3)>,
+L<EVP_PKEY_get_default_digest_nid(3)>,
+L<EVP_PKEY_sign(3)>,
+L<EVP_PKEY_verify(3)>,
+L<EVP_PKEY_verify_recover(3)>,
+
+=head1 HISTORY
+
+This function was first added to OpenSSL 1.1.2.
+
+=head1 COPYRIGHT
+
+Copyright 2006-2018 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>.
+
+=cut