=pod

=head1 NAME

EVP_PKEY_get_default_digest_nid - get default signature digest

=head1 SYNOPSIS

 #include <openssl/evp.h>
 int EVP_PKEY_get_default_digest_nid(EVP_PKEY *pkey, int *pnid);

=head1 DESCRIPTION

The EVP_PKEY_get_default_digest_nid() function sets B<pnid> to the default
message digest NID for the public key signature operations associated with key
B<pkey>.

=head1 NOTES

For all current standard OpenSSL public key algorithms SHA1 is returned.

=head1 RETURN VALUES

The EVP_PKEY_get_default_digest_nid() function returns 1 if the message digest
is advisory (that is other digests can be used) and 2 if it is mandatory (other
digests can not be used).  It returns 0 or a negative value for failure. In
particular a return value of -2 indicates the operation is not supported by the
public key algorithm.

=head1 SEE ALSO

L<EVP_PKEY_CTX_new(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 1.0.0.

=cut
