A collection of web-based tools for working with PSSH boxes (as used for the initialization of DRM systems) and with Widevine Content Decryption Modules (CDMs). There are tools that allow you to:
- serialize and deserialize (create and decode) PSSH boxes
- request decryption keys (obtain a license) from a Widevine DRM licensing server
- convert Widevine CDMs between blob format and “WVD” format
The tools use code from the Rust crate pssh-box compiled to WebAssembly (WASM), and run fully in your web browser (there is no server backend; the tools will work fully offline once loaded).
Tip
You can try out the tools in your browser.
PSSH boxes are used:
-
in an MP4 box of type
psshin an MP4 fragment (CMAF/MP4/ISOBMFF containers) -
in a
<cenc:pssh>element in a DASH MPD manifest -
in DRM initialization data passed to the Encrypted Media Extension of a web browser
-
in an
EXT-X-SESSION-KEYfield of an m3u8 playlist
A PSSH box includes information for a single DRM system. This library supports the PSSH data formats for the following DRM systems:
- Widevine, owned by Google, widely used for DASH streaming
- PlayReady, owned by Microsoft, widely used for DASH streaming
- WisePlay, owned by Huawei
- Irdeto
- Marlin
- Nagra
- The unofficial variant of Apple FairPlay that is used for DASH-like streaming by Netflix
- Common Encryption
PSSH boxes contain (depending on the DRM system) information on the key_ID for which to obtain a content key, the encryption scheme used (e.g. cenc, cbc1, cens or cbcs), the URL of the licence server, and checksum data.
Useful references:
-
Information from the W3C on the cenc initialization data format
-
The Shaka packager utility includes a Python script pssh-box.py which is able to decode and create Widevine initialization data.
This project is licensed under the MIT license. For more information, see the LICENSE file.