We’d like to announce the release of the Capinfo tool.

Morello capabilities hold a lot of information, compressed into a fairly small number of bits, and decoding them manually (e.g. whilst debugging) is non-trivial. Capinfo fully decodes Morello capabilities, showing all permissions, bounds and other properties, and is an invaluable analysis tool for anyone working on compilers, allocators or other software that needs to interact with capabilities at a low level.

Capinfo also shows intermediate values from the decoding process, using terminology consistent with published literature, so you can see exactly how a given capability is decoded.

Also provided is a similar command-line tool, and a Rust crate implementing the common decoding logic. The source for all components is available in Git.