Ever thought that there should be an automated way to handle ssh keys? Do you know the administrators of your servers, and wish that SSH could verify new host keys from them automatically, based on your personal connections to the web-of-trust? Do you wish you could revoke and/or rotate your old SSH authentication keys without having to log into every single machine you have an account on?
Do you administer servers, and wish you could re-key them without sowing massive confusion among your users (or worse, encouraging bad security habits among them)? Do you wish you could grant access to your users by name, instead of by opaque string? Do you wish you could rapidly revoke access to a user (or compromised key) across a group of machines by disabling authentication for that user?
A group of us have been working on a public key infrastructure for SSH.
Monkeysphere makes use of the existing
OpenPGP web-of-trust to fetch and cryptographically validate (and
revoke!) keys. This works in both direction: authorized_keys and
known_hosts are handled. Monkeysphere gives users and admins tools to
deal with SSH keys by thinking about the people and machines to whom the
keys belong, instead of requiring humans to do tedious (and error-prone)
manual key verification.
We have debian packages available which should install against lenny (for i386, amd64, powerpc, and arm architectures at the moment), a mailing list, and open ears for good questions, suggestions and criticism.
If you have a chance to give it a try (as a user or as an admin), it would be great to get feedback.