PyWidevine

1.9.0 verified Sat May 09 auth: no python

A Python implementation of the Widevine Content Decryption Module (CDM) for decrypting DRM-protected content. Version 1.9.0 supports Python 3.9–3.14. Regular releases, roughly quarterly.

pip install pywidevine

Common errors

error ModuleNotFoundError: No module named 'yaml' ↓

cause yaml dependency was not installed unless the 'serve' extras were used. Fixed in v1.8.0.

fix

Upgrade to v1.8.0+ or install yaml separately: pip install pyyaml

error AttributeError: module 'pywidevine' has no attribute 'Cdm' ↓

cause Importing incorrectly; Cdm is only available in top-level since v1.5.1. Older versions or wrong import path.

fix

Use correct import: from pywidevine import Cdm. Or upgrade to v1.5.1+. Alternatively use: from pywidevine.cdm import Cdm

error pywidevine.exceptions.InvalidInitData: Failed to parse PSSH data ↓

cause PSSH data is malformed or not base64 encoded correctly.

fix

Ensure PSSH string is a valid base64-encoded Widevine PSSH box. Use PSSH() with raw bytes or a valid base64 string.

Warnings

breaking Dropped Python 3.8 support in v1.9.0. Python 3.7 dropped in v1.8.0. ↓

fix Upgrade to Python 3.9 or newer. If you must use older Python, pin to pywidevine<1.9.0.

gotcha The 'serve' extras group installs flask and yaml. Without it, yaml dependency was missing before v1.8.0, causing import errors if YAML config is used. ↓

fix Upgrade to v1.8.0+ or install with extras: pip install pywidevine[serve]

gotcha License responses must be the raw bytes returned from the license server, not base64-encoded strings. ↓

fix Ensure the response is passed as bytes, e.g., response.content from requests.

Install

pip install pywidevine[serve]

Imports

Cdm
wrong
```
from pywidevine.cdm import Cdm
```
correct
```
from pywidevine import Cdm
```
Since 1.5.1 Cdm is exported from base package; direct import from submodule also works but is less stable.
PSSH
wrong
```
from pywidevine.pssh import PSSH
```
correct
```
from pywidevine import PSSH
```
Direct import from submodule also works, but base package import is preferred.

Device

wrong

from pywidevine.device import Device

correct

from pywidevine import Device

Same as above.

Quickstart

Basic usage: load a device, open session, get license challenge, parse response, print keys.

from pywidevine import Cdm, Device, PSSH

# Load a Widevine device (WVD file)
device = Device.load('path/to/device.wvd')

# Create a CDM session
cdm = Cdm()
session = cdm.open(device)

# Set a service certificate (optional, for privacy mode)
cert_data = b'...'  # your service certificate bytes
cdm.set_service_certificate(session, cert_data)

# Obtain a license challenge from a PSSH box
pssh = PSSH(pssh='AAAAWnBzc2gAAAAA...')
challenge = cdm.get_license_challenge(session, pssh)

# Send the challenge to your license server, get license response
license_response = b'...'  # bytes from server
cdm.parse_license(session, license_response)

# Extract content keys
for key in cdm.get_keys(session):
    print(f'{key.type}: {key.kid.hex} -> {key.key.hex()}')

cdm.close(session)