ClientIdentification returns empty object, halting create-device

[NellieFromThere]

Describe the bug

When running create-device, it raises an exception. I've been fiddling around and it's because at the Device __init__ step, the function ClientIdentification returns an almost empty object.

The original code is this:

def  __init__(...):
  ...
  self.client_id = ClientIdentification()

After that instruction, self.client_id prints as an empty string, its ByteSize method returns 0, the ClientCapabilities prints as an empty string, and the __sizeof__() is 64.

To Reproduce
I've run this command:

pywidevine create-device -t CHROME -l 3 -k ./my/key -c my/client_blob -v ./my/vmp_blob -o dv

The same happens when the -v argument is ommited.

Expected behavior
A .wvd file should be created.

[rlaphoenix]

Hi,

You have not provided a exception or error log to see what error you are actually facing.
You say it's something to do with the client_id class instance variable, but this is unlikely.

However, I have noticed one possible issue with your CLI call that may have caused it to fail. Please see the commit 29693be and try with that change.

[NellieFromThere]

Sorry for skipping the traceback, I started digging around and forgot to add it.
It's here, using the code cloned after the new commit:

INFO:root:pywidevine version 1.5.3 Copyright (c) 2022-2023 rlaphoenix
INFO:root:https://github.com/rlaphoenix/pywidevine
Traceback (most recent call last):
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/pywidevine/device.py", line 112, in __init__
    self.client_id.ParseFromString(client_id)
google.protobuf.message.DecodeError: Error parsing message

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/username/mambaforge/envs/wide3/bin/pywidevine", line 8, in <module>
    sys.exit(main())
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/click/core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/click/core.py", line 1078, in main
    rv = self.invoke(ctx)
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/click/core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/click/core.py", line 783, in invoke
    return __callback(*args, **kwargs)
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/click/decorators.py", line 34, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/pywidevine/main.py", line 203, in create_device
    device = Device(
  File "/home/username/mambaforge/envs/wide3/lib/python3.9/site-packages/pywidevine/device.py", line 116, in __init__
    raise DecodeError(f"Failed to parse client_id as a ClientIdentification, {e}")
google.protobuf.message.DecodeError: Failed to parse client_id as a ClientIdentification, Error parsing message

I'll try to explain myself better: after seeing the traceback, I looked into device.py, and by adding a few debug lines I saw that the self.client_id object is empty: no client capabilites, _str_ returns an empty string, ByteSize returns 0, I think that's why the ParseFromString method fails. I did not touch the script that contains ClientIdentification because of its format.

My installation method is from the source code, using pip install ., in case it's relevant. I have to say that after installing like this (or from pip's repository) I have to manually install pyYAML, so maybe I'm missing something?

[rlaphoenix]

The error you are getting is simply not an error with this project. Your Client Identification file/blob is invalid or corrupt.

Also, what you are referring to regarding the state of the Device object, __str__, the self.client_id being "empty" e.t.c, is all normal for a newly initialized object. Since it is failing for you when parsing your client ID blob file to the self.client_id, it is never "initialized" and therefore __str__ cannot resolve to anything.

[NellieFromThere]

Ah , I see. Thank you, I'll try to see into that,