crypto/tls: TLS 1.3: Send alert on invalid ECDH share (#126)

Fixes a regression caused by recent integration of Kyber.
cloudflare · Sep 7, 2022 · ca3fe71 · ca3fe71
1 parent 210ad3a
commit ca3fe71
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/src/crypto/tls/handshake_client_tls13.go b/src/crypto/tls/handshake_client_tls13.go
@@ -571,7 +571,9 @@ func (hs *clientHandshakeStateTLS13) establishHandshakeKeys() error {
 			c.sendAlert(alertIllegalParameter)
 			return fmt.Errorf("%s decaps: %w", sk.Scheme().Name(), err)
 		}
-	} else {
+	}
+
+	if sharedKey == nil {
 		c.sendAlert(alertIllegalParameter)
 		return fmt.Errorf("tls: invalid server key share")
 	}