struct for shared secret without clone or copy

src/lib.rs

@@ -48,11 +48,11 @@ impl Secret {
         Secret::from(U256::random(&mut OsRng))
     }
 
-    pub fn diffie_hellman(&self, public: &Public) -> Secret {
+    pub fn diffie_hellman(&self, public: &Public) -> SharedSecret {
         let point = CURVE_25519.point(public.0);
         let p = point * self.0;
 
-        Secret(p.get_x())
+        SharedSecret(p.get_x().to_le_bytes())
     }
 
     pub fn to_bytes(&self) -> [u8; 32] {
@@ -72,6 +72,15 @@ impl From<U256> for Secret {
     }
 }
 
+#[derive(Debug, PartialEq)]
+pub struct SharedSecret([u8; 32]);
+
+impl SharedSecret {
+    pub fn derive_key<T: Fn([u8; 32]) -> [u32; 8]>(self, deriver: T) -> [u32; 8] {
+        deriver(self.0)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -103,7 +112,7 @@ mod tests {
 
         let x_k =
             U256::from_be_hex("0933dc6ed7122bdf2a5f1b0516e218b743868769778787cfa1ac0ae2dfa89891");
-        assert_eq!(x.0, x_k);
+        assert_eq!(x.0, x_k.to_le_bytes());
     }
 
     #[test]