+=item ut_hex COLUMN
+
+Check/untaint hexadecimal values.
+
+=cut
+
+sub ut_hex {
+ my($self, $field) = @_;
+ $self->getfield($field) =~ /^([\da-fA-F]+)$/
+ or return "Illegal (hex) $field: ". $self->getfield($field);
+ $self->setfield($field, uc($1));
+ '';
+}
+
+=item ut_hexn COLUMN
+
+Check/untaint hexadecimal values. May be null.
+
+=cut
+
+sub ut_hexn {
+ my($self, $field) = @_;
+ $self->getfield($field) =~ /^([\da-fA-F]*)$/
+ or return "Illegal (hex) $field: ". $self->getfield($field);
+ $self->setfield($field, uc($1));
+ '';
+}