Initial Commit

src/dh.rs

@@ -0,0 +1,84 @@
+use x25519_dalek::{PublicKey, SharedSecret, StaticSecret};
+use rand_core::OsRng;
+use core::fmt::{Debug, Formatter};
+use core::fmt;
+
+pub struct DhKeyPair {
+    pub private_key: StaticSecret,
+    pub public_key: PublicKey,
+}
+
+impl PartialEq for DhKeyPair {
+    fn eq(&self, other: &Self) -> bool {
+        if self.private_key.to_bytes() != other.private_key.to_bytes() {
+            return false
+        }
+        if self.public_key.to_bytes() != other.public_key.to_bytes() {
+            return false
+        }
+        true
+    }
+}
+
+impl Debug for DhKeyPair {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        f.debug_struct("DhKeyPair")
+            .field("private_key", &self.private_key.to_bytes())
+            .field("public_key", &self.public_key.to_bytes())
+            .finish()
+    }
+}
+
+impl Default for DhKeyPair {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl DhKeyPair {
+    pub fn new() -> Self {
+        let secret = StaticSecret::new(OsRng);
+        let public = PublicKey::from(&secret);
+        DhKeyPair {
+            private_key: secret,
+            public_key: public,
+        }
+    }
+
+    pub fn key_agreement(&self, public_key: &PublicKey) -> SharedSecret {
+        self.private_key.diffie_hellman(public_key)
+    }
+}
+
+#[cfg(test)]
+pub fn gen_shared_secret() -> SharedSecret {
+    let alice_pair = DhKeyPair::new();
+    let bob_pair = DhKeyPair::new();
+    alice_pair.key_agreement(&bob_pair.public_key)
+}
+
+#[cfg(test)]
+pub fn gen_key_pair() -> DhKeyPair {
+    DhKeyPair::new()
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::dh::DhKeyPair;
+
+    #[test]
+    fn key_generation() {
+        let pair_1 = DhKeyPair::new();
+        let pair_2 = DhKeyPair::new();
+        assert_ne!(pair_1, pair_2)
+    }
+
+    #[test]
+    fn key_agreement() {
+        let alice_pair = DhKeyPair::new();
+        let bob_pair = DhKeyPair::new();
+        let alice_shared_secret = alice_pair.key_agreement(&bob_pair.public_key);
+        let bob_shared_secret = bob_pair.key_agreement(&alice_pair.public_key);
+        assert_eq!(alice_shared_secret.as_bytes(), bob_shared_secret.as_bytes())
+    }
+}