Add IdentityKey struct

src/signal.rs

@@ -1,7 +1,63 @@
+use std::convert::TryFrom;
+
 pub mod curve;
 mod error;
 pub mod kdf;
 pub(crate) mod proto;
-pub mod ratchet;
 
+pub mod ratchet;
 pub use error::Error;
+
+pub struct IdentityKey {
+    public_key: Box<dyn curve::PublicKey>,
+}
+
+impl IdentityKey {
+    pub fn public_key(&self) -> &dyn curve::PublicKey {
+        self.public_key.as_ref()
+    }
+
+    pub fn serialize(&self) -> Box<[u8]> {
+        self.public_key.serialize()
+    }
+}
+
+impl TryFrom<&[u8]> for IdentityKey {
+    type Error = curve::InvalidKeyError;
+
+    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
+        curve::decode_point(value).map(|public_key| Self { public_key })
+    }
+}
+
+impl<T> From<T> for IdentityKey
+where
+    T: curve::PublicKey + 'static,
+{
+    fn from(value: T) -> Self {
+        Self {
+            public_key: Box::new(value),
+        }
+    }
+}
+
+impl From<Box<dyn curve::PublicKey>> for IdentityKey {
+    fn from(value: Box<dyn curve::PublicKey>) -> Self {
+        Self { public_key: value }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_from() {
+        use rand::rngs::OsRng;
+
+        let key_pair = curve::KeyPair::new(&mut OsRng);
+        let key_pair_public_serialized = key_pair.public_key.serialize();
+        let identity_key = IdentityKey::from(key_pair.public_key);
+        assert_eq!(key_pair_public_serialized, identity_key.serialize());
+    }
+}