[Assignment-4] added mitm attack implementation

Assignment 4 - Protokollsicherheit (Praxis)/proxy/proxymodules/mitm.py

@@ -0,0 +1,38 @@
+import os
+import json
+import base64
+import os.path as path
+
+
+# protocol 1: flag{m4n_1n_th3_m1ddl3_w0w}
+class Module:
+    def __init__(self, incoming=False, verbose=False, options=None):
+        # extract the file name from __file__. __file__ is proxymodules/name.py
+        self.name = path.splitext(path.basename(__file__))[0]
+        self.description = 'Simply print the received data as text'
+        self.incoming = incoming  # incoming means module is on -im chain
+        self.find = None  # if find is not None, this text will be highlighted
+
+    def execute(self, data):
+        print(f"Incoming data: {data}")
+        data_json = json.loads(data)
+
+        if data_json.get("type") == "HANDSHAKE":
+            return data
+        
+        elif data_json.get("id") == 1:
+            data_json["content"] = data_json["content"].replace("Bob","Eve")
+        
+        elif data_json.get("id") == 3:
+            data_json["id"] = 4
+            data_json["sender"] = "Bob"
+            data_json["receiver"] = "Alice"
+            data_json["content"] = str(base64.b64encode(os.urandom(16)))
+        
+        data = json.dumps(data_json) + "\n"
+        print(f"Outgoing data: {data}")
+        return data
+
+
+if __name__ == '__main__':
+    print('This module is not supposed to be executed alone!')