Add Support for Brotli Compression

[qkaiser]

Description
Brotli is a general-purpose, lossless compression algorithm developed by Google, widely used for web content compression (e.g., serving compressed static files).

References

• Official Brotli GitHub
• RFC 7932: Brotli Compressed Data Format

How to Craft

1. Install Brotli CLI (e.g., sudo apt-get install brotli or via npm install brotli).
2. Run:

   brotli --quality=9 --input file_to_compress --output file_to_compress.br

Magic Value / Signature

• No fixed magic number. Brotli’s initial bytes encode parameters (like window size), but it’s not a static signature.
• Detection often relies on partial stream parsing or heuristics.

How to Extract / Decompress

• Tool: Use the brotli CLI to decompress:

  brotli --decompress file_to_compress.br

• Python Library: The brotli library supports decompression in Python.

Determining End Offset

• Brotli streams are self-terminating.
• unblob can either:
  • Decode the stream until it ends.
  • Use the container file size if available.
• Proper detection requires partial decoding or known container boundaries to confirm the stream ends where expected.