Capsicum is a lightweight OS capability and sandbox framework developed at the University of Cambridge Computer Laboratory.
Capsicum extends the POSIX API, providing several new OS primitives to support object-capability security on UNIX-like operating systems:
- capabilities – refined file descriptors with fine-grained rights
- capability mode – process sandboxes that deny access to global namespaces
- process descriptors – capability-centric process ID replacement
- anonymous shared memory objects – an extension to the POSIX shared memory API to support anonymous swap objects associated with file descriptors (capabilities)
- rtld-elf-cap – modified ELF run-time linker to construct sandboxed applications
- libcapsicum – library to create and use capabilities and sandboxed components
- libuserangel – library allowing sandboxed applications or components to interact with user angels, such as Power Boxes.
- chromium-capsicum – a version of Google’s Chromium web browser that uses capability mode and capabilities to provide effective sandboxing of high-risk web page rendering.
Capsicum has been prototyped on FreeBSD 8.x, and the experimental code is BSD-licensed to encourage open source, research, and commercial deployment.