Fix s7 parameter length calculation

mushorg · Oct 6, 2018 · b2d2d51 · b2d2d51
1 parent 4dcf46f
commit b2d2d51
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Showing 2 changed files with 11 additions and 10 deletions.
diff --git a/conpot/protocols/s7comm/s7.py b/conpot/protocols/s7comm/s7.py
@@ -21,8 +21,8 @@ def __init__(self, pdu_type=0, reserved=0, request_id=0, result_info=0, paramete
         self.pdu_type = pdu_type
         self.reserved = reserved
         self.request_id = request_id
-        # sometimes "parameters" happen to be of type int, not str
-        self.param_length = len(str(parameters))
+        # sometimes "parameters" happen to be of type int, and not a byte string
+        self.param_length = len(parameters) if isinstance(parameters, bytes) else len(str(parameters))
         self.data_length = len(data)
         self.result_info = result_info
         self.parameters = parameters

diff --git a/conpot/tests/helpers/s7comm_client.py b/conpot/tests/helpers/s7comm_client.py
@@ -22,14 +22,16 @@
 import struct
 import socket
 import string
-# from conpot.protocols.s7comm.tpkt import cleanse_byte_string
 
 __FILTER = "".join([' '] + [' ' if chr(x) not in string.printable or chr(x) in string.whitespace else chr(x)
                             for x in range(1, 256)])
 
 
+_bytes_to_str = lambda items : (value.decode('ascii') if isinstance(value, bytes) else value for value in items)
+
+
 def StripUnprintable(msg):
-    return msg.translate(__FILTER)
+    return msg.decode('ascii').translate(__FILTER)
 
 
 class TPKTPacket:
@@ -315,8 +317,8 @@ def GetIdentity(ip, port, src_tsap, dst_tsap):
                 7: 'Basic Firmware'
             },
             'packer': {
-                (1, 6): lambda packet: "{0:s} v.{2:d}.{3:d}".format(*unpack('!20sHBBH', packet)),
-                (7,): lambda packet: "{0:s} v.{3:d}.{4:d}.{5:d}".format(*unpack('!20sHBBBB', packet))
+                (1, 6): lambda packet: "{0:s} v.{2:d}.{3:d}".format(*_bytes_to_str(unpack('!20sHBBH', packet))),
+                (7,): lambda packet: "{0:s} v.{3:d}.{4:d}.{5:d}".format(*_bytes_to_str(unpack('!20sHBBBB', packet)))
             }
         },
         0x1c: {
@@ -335,9 +337,9 @@ def GetIdentity(ip, port, src_tsap, dst_tsap):
                 11: 'Location designation of a module'
             },
             'packer': {
-                (1, 2, 5): lambda packet: "%s" % packet[:24],
-                (3, 7, 8): lambda packet: "%s" % packet[:32],
-                (4,): lambda packet: "%s" % packet[:26]
+                (1, 2, 5): lambda packet: "%s" % packet[:24].decode('ascii'),
+                (3, 7, 8): lambda packet: "%s" % packet[:32].decode('ascii'),
+                (4,): lambda packet: "%s" % packet[:26].decode('ascii')
             }
         }
     }
@@ -351,7 +353,6 @@ def GetIdentity(ip, port, src_tsap, dst_tsap):
         except S7Error:
             continue
 
-        indexes = szl_dict[szl_id]['indexes']
         packers = szl_dict[szl_id]['packer']
 
         for item in entities: