From fe1a25e7638bbc17b0d6e3fa03e9900fc198be7b Mon Sep 17 00:00:00 2001
From: Theophile BREZOT <theophile.brezot@cosmian.com>
Date: Wed, 21 Sep 2022 09:17:49 +0200
Subject: [PATCH] Add test on `X225519KeyPair`

---
 src/asymmetric_crypto/curve25519.rs | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/asymmetric_crypto/curve25519.rs b/src/asymmetric_crypto/curve25519.rs
index 49d0d2c..a114279 100644
--- a/src/asymmetric_crypto/curve25519.rs
+++ b/src/asymmetric_crypto/curve25519.rs
@@ -347,13 +347,7 @@ impl ZeroizeOnDrop for X25519KeyPair {}
 
 #[cfg(test)]
 mod test {
-    use crate::{
-        asymmetric_crypto::curve25519::{
-            X25519PrivateKey, X25519PublicKey, X25519_PK_LENGTH, X25519_SK_LENGTH,
-        },
-        entropy::CsRng,
-        KeyTrait,
-    };
+    use crate::{asymmetric_crypto::curve25519::*, entropy::CsRng, KeyTrait};
 
     #[test]
     fn test_private_key_serialization() {
@@ -372,4 +366,18 @@ mod test {
         let recovered = super::X25519PublicKey::try_from(bytes).unwrap();
         assert_eq!(pk, recovered);
     }
+
+    #[test]
+    fn test_dh_key_pair() {
+        let mut rng = CsRng::new();
+        let kp1 = X25519KeyPair::new(&mut rng);
+        let kp2 = X25519KeyPair::new(&mut rng);
+        // check the keys are randomly generated
+        assert_ne!(kp1, kp2);
+        // check DH Key exchange is possible
+        assert_eq!(
+            kp1.public_key() * kp2.private_key(),
+            kp2.public_key() * kp1.private_key()
+        );
+    }
 }