playready_experiment.py

   1 #!/usr/bin/env python3
   2 #
   3 # playready_experiment.py - Example of SmoothStreaming PlayReady authentication
   4 #
   5 # Copyright (C) 2016  Antonio Ospite <ao2@ao2.it>
   6 #
   7 # This program is free software: you can redistribute it and/or modify it under
   8 # the terms of the GNU General Public License as published by the Free Software
   9 # Foundation, either version 3 of the License, or (at your option) any later
  10 # version.
  11 #
  12 # This program is distributed in the hope that it will be useful, but WITHOUT
  13 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  14 # FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  15 # details.
  16 #
  17 # You should have received a copy of the GNU General Public License along with
  18 # this program.  If not, see <http://www.gnu.org/licenses/>.
  19 #
  20 #
  21 # Experiment on how to use the ProtectionHeader element in SmoothSTreaming
  22 # manifest files.
  23 #
  24 # The code is just a demonstration of how to decode the ProtectionHeader element
  25 # content, it is not supposed to do nothing actually useful.
  26 #
  27 # Based on the PlayReady Header Object specification:
  28 # http://download.microsoft.com/download/1/4/7/1475C862-6B67-44B2-AF31-ABC83EA68292/PlayReady%20Header%20Object%20(7-2-2012).docx
  29
  30 import base64
  31 import struct
  32 import sys
  33 import xml.etree.ElementTree as etree
  34
  35 from pysimplesoap.client import SoapClient
  36 from pysimplesoap.simplexml import SimpleXMLElement
  37
  38
  39 def get_right_management_header(protection_header_text):
  40     play_ready_header_objects = base64.b64decode(protection_header_text)
  41
  42     offset = 0
  43
  44     field_size = 4
  45     total_size = struct.unpack("<L", play_ready_header_objects[offset:offset + field_size])[0]
  46     offset += field_size
  47
  48     if total_size != len(play_ready_header_objects):
  49         sys.stderr.write("Error, unexpected size.\n")
  50         sys.exit(1)
  51
  52     field_size = 2
  53     count = struct.unpack("<H", play_ready_header_objects[offset:offset + field_size])[0]
  54     offset += field_size
  55
  56     for i in range(count):
  57         field_size = 2
  58         record_type = struct.unpack("<H", play_ready_header_objects[offset:offset + field_size])[0]
  59         offset += field_size
  60
  61         field_size = 2
  62         record_length = struct.unpack("<H", play_ready_header_objects[offset:offset + field_size])[0]
  63         offset += field_size
  64
  65         if record_type == 1:
  66             right_management_header = play_ready_header_objects[offset:offset + record_length].decode("UTF-16")
  67             return right_management_header
  68         else:
  69             sys.stderr.write("Error, unsupported record type. Skipping.\n")
  70             offset += record_length
  71
  72
  73 def main():
  74     if len(sys.argv) != 2:
  75         sys.stderr.write("usage: %s <manifest>\n" % sys.argv[0])
  76         sys.exit(1)
  77
  78     manifest_filename = sys.argv[1]
  79
  80     manifest = etree.parse(manifest_filename)
  81     protection_header = manifest.find(".//Protection/ProtectionHeader")
  82
  83     challenge = get_right_management_header(protection_header.text)
  84
  85     challenge_xml = etree.fromstring(challenge)
  86     la_url = challenge_xml.find(".//{http://schemas.microsoft.com/DRM/2007/03/PlayReadyHeader}LA_URL").text
  87
  88     client = SoapClient(
  89         location=la_url,
  90         action='http://schemas.microsoft.com/DRM/2007/03/protocols/',
  91         soap_ns='soap', trace=True, ns=False)
  92
  93     params = SimpleXMLElement("""<AcquireLicense xmlns="http://schemas.microsoft.com/DRM/2007/03/protocols"><challenge>""" +
  94                               challenge +
  95                               """</challenge></AcquireLicense>""")
  96
  97     response = client.call('AcquireLicense', params)
  98     print(response)
  99
 100 if __name__ == "__main__":
 101     main()