https://github.com/emarsden/pssh-box-wasm

Parsing and printing PSSH boxes for DRM systems, in WebAssembly.
https://github.com/emarsden/pssh-box-wasm

decoding drm pssh webassembly

Last synced: 27 days ago
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Parsing and printing PSSH boxes for DRM systems, in WebAssembly.

• Host: GitHub
• URL: https://github.com/emarsden/pssh-box-wasm
• Owner: emarsden
• License: mit
• Created: 2024-02-14T10:53:01.000Z (10 months ago)
• Default Branch: main
• Last Pushed: 2024-04-13T08:01:41.000Z (8 months ago)
• Last Synced: 2024-04-13T20:50:40.107Z (8 months ago)
• Topics: decoding, drm, pssh, webassembly
• Language: JavaScript
• Homepage: https://emarsden.github.io/pssh-box-wasm/
• Size: 79.1 KB
• Stars: 9
• Watchers: 1
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# pssh-box-wasm

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](https://crates.io/crates/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](https://emarsden.github.io/pssh-box-wasm/). 

PSSH boxes are used:

- in an MP4 box of type `pssh` in an MP4 fragment (CMAF/MP4/ISOBMFF containers)

- in a `` 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-KEY` field 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](https://www.w3.org/TR/eme-initdata-cenc/)

- [Widevine diagnostics tools](https://integration.widevine.com/diagnostics) 

- The Shaka packager utility includes a Python script

  [pssh-box.py](https://github.com/shaka-project/shaka-packager/blob/main/packager/tools/pssh/pssh-box.py)

  which is able to decode and create Widevine initialization data.

## License

This project is licensed under the MIT license. For more information, see the `LICENSE` file.