x-wing: impl KeyExport for DecapsulationKey (#229)

Author: tarcieri

x-wing/src/lib.rs

@@ -242,13 +242,19 @@ impl KeySizeUser for DecapsulationKey {
 }
 
 impl KeyInit for DecapsulationKey {
-    fn new(key: &ArrayN<u8, 32>) -> Self {
+    fn new(key: &Key<Self>) -> Self {
         let (_sk_m, _sk_x, pk_m, pk_x) = expand_key(key.as_ref());
         let ek = EncapsulationKey { pk_m, pk_x };
         Self { sk: key.0, ek }
     }
 }
 
+impl KeyExport for DecapsulationKey {
+    fn to_bytes(&self) -> Key<Self> {
+        self.sk.into()
+    }
+}
+
 #[cfg(feature = "zeroize")]
 impl ZeroizeOnDrop for DecapsulationKey {}