129 lines
4.6 KiB
Python
129 lines
4.6 KiB
Python
#!/usr/bin/python
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# -*- coding: UTF-8 -*-
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#/**
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# * S1AP test utility
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# * Script to test pycrate decoding/re-encoding for APER
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# * Script is using tshark json pipe input which was generated from real pcap
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# *
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# * Usage:
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# * Use any s1ap pcap (trace.pcap)
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# * ./tshark -T ek -x -j s1ap -r trace.pcap > trace.json
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# * python test_s1ap.py
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# *
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# * Copyright 2017 Martin Kacer, H21 lab
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# *
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# *
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# *
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# * Software Name : pycrate
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# * Version : 0.4
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# *
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# * Copyright 2017 Benoit Michau. ANSSI.
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# *
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# * This library is free software; you can redistribute it and/or
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# * modify it under the terms of the GNU Lesser General Public
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# * License as published by the Free Software Foundation; either
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# * version 2.1 of the License, or (at your option) any later version.
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# *
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# * This library is distributed in the hope that it will be useful,
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# * but WITHOUT ANY WARRANTY; without even the implied warranty of
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# * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# * Lesser General Public License for more details.
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# *
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# * You should have received a copy of the GNU Lesser General Public
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# * License along with this library; if not, write to the Free Software
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# * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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# * MA 02110-1301 USA
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# *
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# *--------------------------------------------------------
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# * File Name : test_s1ap.py
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# * Created : 2017-12-28
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# * Authors : Martin Kacer
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# *--------------------------------------------------------
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#*/
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import sys
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import time
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import random
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import traceback
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import binascii
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from pycrate_asn1dir import S1AP
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# Global options to control the script behavior
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option_print_verbose = True # print verbose decoding output
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option_fuzzing_messages = False # fuzz messages before pycrate decoding
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option_reencode = True # re-encode into hex and compare with the hex input
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#
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with open('res/s1ap_pcapr.json') as f:
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lines = f.readlines()
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for s in lines:
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i = s.find('"s1ap_raw": "')
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ln = len('"s1ap_raw": "')
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if (i > 0):
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#print(s[i:])
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subs = s[i+ln:]
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l = subs.find('"')
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s1ap_hex = subs[0:l]
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if (option_print_verbose):
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print("HEX IN: " + s1ap_hex)
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# fuzzing of messages
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if (option_fuzzing_messages):
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for i in range (0, 1):
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if s1ap_hex != '':
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s1ap_hex_f = s1ap_hex
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position = int(random.randint(0, len(s1ap_hex_f))/2)
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position = position * 2
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s1ap_hex_f = s1ap_hex_f[:position] + format(random.randint(0, 255), '02x') + s1ap_hex_f[position + 2:]
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s1ap_hex = s1ap_hex_f
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if (option_print_verbose):
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print("FUZZ IN: " + s1ap_hex)
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try:
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# decode using pycrate
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s1ap = S1AP.S1AP_PDU_Descriptions.S1AP_PDU
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s1ap.from_aper(binascii.unhexlify(s1ap_hex))
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s1ap_decoded = s1ap.get_val()
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# verbose output
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if (option_print_verbose):
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print(s1ap_decoded)
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print(s1ap.to_asn1())
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#
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# re-encode using pycrate
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if (option_reencode == True):
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s1ap.set_val(s1ap_decoded)
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s1ap_hex_out = str(binascii.hexlify(s1ap.to_aper()))
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if (option_print_verbose):
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print("HEX OUT:" + s1ap_hex_out)
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# decode again and try to check diff
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s1ap_reencoded = S1AP.S1AP_PDU_Descriptions.S1AP_PDU
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s1ap_reencoded.from_aper(binascii.unhexlify(s1ap_hex))
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s1ap_decoded = str(s1ap.get_val())
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s1ap_reencoded_decoded = str(s1ap.get_val())
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if (s1ap_decoded != s1ap_reencoded_decoded):
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print("!!!!!!! Re-encoding error begin !!!!!!!")
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print("ENCODED IN: " + s1ap_hex)
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print("RE-RENCODED: " + s1ap_hex_out)
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print(s1ap_decoded)
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print(s1ap_reencoded_decoded)
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print("!!!!!!! Re-encoding error end !!!!!!!")
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#
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#
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except Exception as err:
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print("!!!!!!! Exception begin !!!!!!!")
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print(err)
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traceback.print_exc()
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print("!!!!!!! Exception end !!!!!!!")
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