Nokia/Alcatel-Lucent router backup configuration tool

nokia-router-cfg-tool.py

#!/usr/bin/env python3


#
# Nokia/Alcatel-Lucent router backup configuration tool
#
# Features:
# - Unpack/repack .cfg files generated from the backup and restore functionnality
#   in order to modify the full router configuration
# - Decrypt/encrypt the passwords/secret values present in the configuration
#
# Blog post: https://0x41.cf/reversing/2019/10/08/unlocking-nokia-g240wa.html
#
# Released under the MIT License (http://opensource.org/licenses/MIT)
# Copyright (c) Sami Alaoui Kendil (thedroidgeek)
#


import sys
import zlib
import struct
import base64
import binascii
import datetime


big_endian = True
encrypted_cfg = False


def u32(val):
    return struct.unpack('>I' if big_endian else '<I', val)[0]

def p32(val):
    return struct.pack('>I' if big_endian else '<I', val)

def checkendian(cfg):
    if (cfg[0:4] == b'\x00\x12\x31\x23'):
        return True
    elif (cfg[0:4] == b'\x23\x31\x12\x00'):
        return False
    else:
        return None


class RouterCrypto:

    def __init__(self):

        from Crypto.Cipher import AES

        # key and IV for AES
        key = '3D A3 73 D7 DC 82 2E 2A 47 0D EC 37 89 6E 80 D7 2C 49 B3 16 29 DD C9 97 35 4B 84 03 91 77 9E A4'
        iv  = 'D0 E6 DC CD A7 4A 00 DF 76 0F C0 85 11 CB 05 EA'

        # create AES-128-CBC cipher
        self.cipher = AES.new(bytes(bytearray.fromhex(key)), AES.MODE_CBC, bytes(bytearray.fromhex(iv)))

    def decrypt(self, data):

        output = self.cipher.decrypt(data)

        # remove PKCS#7 padding
        return output[:-ord(output[-1:])]

    def encrypt(self, data):

        # add PKCS#7 padding for 128-bit AES
        pad_num = (16 - (len(data) % 16))
        data += chr(pad_num).encode() * pad_num

        return self.cipher.encrypt(data)


#
# unpack xml from cfg
#

if (len(sys.argv) == 3 and sys.argv[1] == '-u'):

    # line feed
    print('')

    # read the cfg file
    cf = open(sys.argv[2], 'rb')
    cfg_data = cf.read()

    # check cfg file magic (0x123123) and determine endianness
    big_endian = checkendian(cfg_data)

    if big_endian == None:

        # check if config is encrypted
        decrypted = None
        try:
            # decrypt and check validity
            decrypted = RouterCrypto().decrypt(cfg_data)
            big_endian = checkendian(decrypted)
        except ValueError:
            pass

        # if decryption failed, or still invalid, bail out
        if big_endian == None:
            print('invalid cfg file/magic :(\n')
            exit()

        # set decrypted cfg buffer and encryption flag
        print('-> encrypted cfg detected')
        cfg_data = decrypted
        encrypted_cfg = True

    # log endianness
    if big_endian:
        print('-> big endian CPU detected')
    else:
        print('-> little endian CPU detected')

    # get fw_magic (unknown, could be fw version/compile time, hw serial number, etc.)
    fw_magic = u32(cfg_data[0x10:0x14])
    print('-> fw_magic = ' + hex(fw_magic))

    # get the size of the compressed data
    data_size = u32(cfg_data[4:8])

    # get the compressed data
    compressed = cfg_data[0x14 : 0x14 + data_size]

    # get the checksum of the compressed data
    checksum = u32(cfg_data[8:12])

    # verify the checksum
    if (binascii.crc32(compressed) & 0xFFFFFFFF != checksum):
        print('\nCRC32 checksum failed :(\n')
        exit()

    # unpack the config
    xml_data = zlib.decompress(compressed)

    # output the xml file
    out_filename = 'config-%s.xml' % datetime.datetime.now().strftime('%d%m%Y-%H%M%S')
    of = open(out_filename, 'wb')
    of.write(xml_data)

    print('\nunpacked as: ' + out_filename)

    print('\n# repack with:')
    print('%s %s %s %s\n' % (sys.argv[0], ('-pb' if big_endian else '-pl') + ('e' if encrypted_cfg else ''), out_filename, hex(fw_magic)))

    cf.close()
    of.close()


#
# generate cfg from xml
#

elif (len(sys.argv) == 4 and (sys.argv[1][:3] == '-pb' or sys.argv[1][:3] == '-pl')):

    fw_magic = 0

    try:
        # parse hex string
        fw_magic = int(sys.argv[3], 16)
        # 32-bit check
        p32(fw_magic)
    except:
        print('\ninvalid magic value specified (32-bit hex)\n')
        exit()

    big_endian = sys.argv[1][:3] == '-pb'
    encrypted_cfg = sys.argv[1][3:] == 'e'

    out_filename = 'config-%s.cfg' % datetime.datetime.now().strftime('%d%m%Y-%H%M%S')

    # read the xml file
    xf = open(sys.argv[2], 'rb')
    xml_data = xf.read()
    xf.close()

    # compress using default zlib compression
    compressed = zlib.compress(xml_data)

    ## construct the header ##
    # magic
    cfg_data = p32(0x123123)
    # size of compressed data
    cfg_data += p32(len(compressed))
    # crc32 checksum
    cfg_data += p32(binascii.crc32(compressed) & 0xFFFFFFFF)
    # size of xml file
    cfg_data += p32(len(xml_data) + 1)
    # fw_magic
    cfg_data += p32(fw_magic)

    # add the compressed xml
    cfg_data += compressed

    # encrypt if necessary
    if encrypted_cfg:
        cfg_data = RouterCrypto().encrypt(cfg_data)

    # write the cfg file
    of = open(out_filename, 'wb')
    of.write(cfg_data)
    of.close()

    print('\npacked as: ' + out_filename + '\n')


#
# decrypt/encrypt secret value
#

elif (len(sys.argv) == 3 and (sys.argv[1] == '-d' or sys.argv[1] == '-e')):

    decrypt_mode = sys.argv[1] == '-d'

    if decrypt_mode:

        # base64 decode + AES decrypt
        print('\ndecrypted: ' + RouterCrypto().decrypt(base64.b64decode(sys.argv[2])).decode('UTF-8') + '\n')

    else:

        # AES encrypt + base64 encode
        print('\nencrypted: ' + base64.b64encode(RouterCrypto().encrypt(sys.argv[2].encode())).decode('UTF-8') + '\n')


else:

    print('\n#\n# Nokia/Alcatel-Lucent router backup configuration tool\n#\n')
    print('# unpack (cfg to xml)\n')
    print(sys.argv[0] + ' -u config.cfg\n')
    print('# pack (xml to cfg)\n')
    print(sys.argv[0] + ' -pb  config.xml 0x13377331 # big endian, no encryption, fw_magic = 0x13377331')
    print(sys.argv[0] + ' -pl  config.xml 0x13377331 # little endian, ...')
    print(sys.argv[0] + ' -pbe config.xml 0x13377331 # big endian, with encryption, ...')
    print(sys.argv[0] + ' -ple config.xml 0x13377331 # ...\n')
    print('# decrypt/encrypt secret values within xml (ealgo="ab")\n')
    print(sys.argv[0] + ' -d OYdLWUVDdKQTPaCIeTqniA==')
    print(sys.argv[0] + ' -e admin\n')

https://www.youtube.com/watch?v=taA0P52jUXw
Worked for XS-2426G-A 3FE49385HJJI85(1.2201.185)

Maybe someone will be able to update the script?

Can anyone share stock firmware for 2425g-a , i borked by setting the operator id to 0000 and reset the router. i can't get anywhere from internet.

@daemonlover7 You can refer here for the firmware : Firmware Link

Hello @thedroidgeek Thankyou for the detailed instruction , although this is the first time ive used python and still able get to root user succesfully on G-140w-F & G-140w-C . now what i want is to Modify the default configuration of the ONT ( that means if we hard reset the ONT it will restore our modified configuration). Thanks Again for the Guide
below are the available cmds.

Hello how did you do to access ONTUSER my model G-140W-H and I believe it is different in some configuration. I already set LimitAccount_ONTUSER to false, but without success when logging via telnet. Can you help me. I can send the configuration file.

Hi... i want help on this one also... do you have the answers already?

Any Idea where i can Find the list of OperatorID in the router itself ?
Also for anyone Looking Info on Nokia G-1425-MA specially from Classictech :
Web Username : classicadmin
Web Password : Cr3d3nti@lofNok!aONT0061_P@SSW)RD
https://github.com/diwash5/nokia_G-1425-MA

Any Idea where i can Find the list of OperatorID in the router itself ? Also for anyone Looking Info on Nokia G-1425-MA specially from Classictech : Web Username : classicadmin Web Password : Cr3d3nti@lofNok!aONT0061_P@SSW)RD https://github.com/diwash5/nokia_G-1425-MA

Great bro