diff --git a/rev_shell.py b/rev_shell.py
index 16b47f4..93f1899 100755
--- a/rev_shell.py
+++ b/rev_shell.py
@@ -98,6 +98,7 @@ class ShellListener:
 
             print("[-] Disconnected")
             self.connection = None
+            self.running = False
 
     def close(self):
         self.running = False
@@ -432,7 +433,7 @@ def wait_for_connection(listener, timeout=None, prompt=True):
         else:
             print(prompt)
 
-    while listener.connection is None:
+    while listener.connection is None and listener.running:
         time.sleep(0.5)
         if timeout is not None:
             diff = time.time() - start
diff --git a/util.py b/util.py
index 78d1619..696c013 100755
--- a/util.py
+++ b/util.py
@@ -321,7 +321,7 @@ def pad(x, n, b=b"\x00", s="r"):
             x = (n-(len(x)%n))*b + x
     return x
 
-def xor(a, b):
+def xor(a, b, *args):
     if isinstance(a, int):
         a = a.to_bytes(math.ceil(math.log(a)/math.log(2)/8.0))
     if isinstance(b, int):
@@ -345,9 +345,12 @@ def xor(a, b):
         if type(b) not in (bytes, bytearray):
             b = b.encode()
 
-        
+    result = b"".join([bytes([c1 ^ c2]) for (c1,c2) in zip(a, b) ])
 
-    return b"".join([bytes([c1 ^ c2]) for (c1,c2) in zip(a, b) ])
+    if len(args) > 0:
+        result = xor(result, *args)
+
+    return result
 
 def base64urldecode(data):
     if isinstance(data, str):