Alex Willmer - CloudABI: Capability based security on Linux/Unix
Take POSIX, add capability-based security, then remove anything that
conflicts. The result is CloudABI, available for BSD, Linux, OSX et
al.
A CloudABI process is incapable of any action that has a global impact
It can only affect the file descriptors you provide. As a result even
unknown binaries can safely be executed - without the need for
containers, virtual machines, or other sandboxes.
This talk will introduce CloudABI, how to use it with Python, the
benefits, and the trade-offs.
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[CloudABI] is a new POSIX based computing environment that brings [capability-based security] to BSD, Linux, OSX et al.
Unlike traditional Unix, if a CloudABI process goes rogue it _cannot_
execute random binaries, or read arbitrary files. This is achieved by
removing `open()` & any other API able to acquire global resources.
Instead a CloudABI process must be granted _capabilities_ to specific
resources (e.g. directories, files, sockets) in the form of file
descriptors. If a process only has a descriptor for `/var/www` then
it's _incapable_ of affecting any file or folder outside that
directory.
This talk will
- Review the security & reusability problems of Linux & Unix processes
- Introduce capability-based security
- Summarize the design of CloudABI - its benefits & trade-offs
- Demonstrate how to write Python software for CloudABI & run it
- Point out the pitfalls & gotchas to be aware of
- Discuss the current & future status of CloudABI
CloudABI began life on FreeBSD. It also runs DragonFly BSD, NetBSD,
PC-BSD, Arch Linux, Debian, Ubuntu, & OS X. The API & ABI are kernel
agnostic - a CloudABI binary can run on any supported kernel. The
design is evolved from
[Capsicum], a
library that allows processes to drop access to undesired syscalls at
runtime. CloudABI applies this at build time to make testing & lock-
down easier. |