Fix ecdh ephemeral key for curve25519

Signed-off-by: Nguyen Van Nguyen <nguyennv1981@gmail.com>
web-of-trust · Nov 27, 2024 · 39e3053 · 39e3053
1 parent f7052f4
commit 39e3053
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/lib/src/packet/key/ecdh_session_key_params.dart b/lib/src/packet/key/ecdh_session_key_params.dart
@@ -68,7 +68,10 @@ class ECDHSessionKeyParams extends SessionKeyParams {
         final privateKey = nacl.PrivateKey.fromSeed(
           Helper.secureRandom().nextBytes(TweetNaCl.seedSize),
         );
-        ephemeralKey = privateKey.publicKey.asTypedList.toBigIntWithSign(1);
+        ephemeralKey = Uint8List.fromList([
+          0x40,
+          ...privateKey.publicKey.asTypedList,
+        ]).toBigIntWithSign(1);
         sharedKey = TweetNaCl.crypto_scalarmult(
           Uint8List(TweetNaCl.sharedKeyLength),
           privateKey.asTypedList,