Secdns ergonomic (#21)

src/extensions/secdns.rs

@@ -6,6 +6,7 @@ use std::borrow::Cow;
 use std::fmt::Write;
 use std::time::Duration;
 
+use crate::common::NoExtension;
 use crate::request::{Extension, Transaction};
 
 pub const XMLNS: &str = "urn:ietf:params:xml:ns:secDNS-1.1";
@@ -13,7 +14,7 @@ pub const XMLNS: &str = "urn:ietf:params:xml:ns:secDNS-1.1";
 impl<'a> Transaction<CreateData<'a>> for crate::domain::create::DomainCreate<'a> {}
 
 impl<'a> Extension for CreateData<'a> {
-    type Response = ();
+    type Response = NoExtension;
 }
 
 #[derive(Debug, ToXml)]
@@ -122,7 +123,7 @@ impl<'a> DsDataType<'a> {
         key_tag: u16,
         algorithm: Algorithm,
         digest_type: DigestAlgorithm,
-        digest: &'a str,
+        digest: impl Into<Cow<'a, str>>,
         key_data: Option<KeyDataType<'a>>,
     ) -> Self {
         Self {