Ubuntu Manpage: monkeysphere - ssh and TLS authentication framework using OpenPGP Web of Trust

NAME

       monkeysphere - ssh and TLS authentication framework using OpenPGP Web of Trust

DESCRIPTION

       Monkeysphere  is  a  framework  to  leverage  the  OpenPGP  web  of  trust  for OpenSSH and TLS key-based
       authentication.  OpenPGP keys are tracked via GnuPG, and added to  the  authorized_keys  and  known_hosts
       files used by OpenSSH for connection authentication.  Monkeysphere can also be used by a validation agent
       to validate TLS connections (e.g. https).

IDENTITY CERTIFIERS

Each host that uses the Monkeysphere to authenticate its remote users needs some way to determine that
those users are who they claim to be. SSH permits key-based authentication, but we want instead to bind
authenticators to human-comprehensible user identities. This switch from raw keys to User IDs makes it
possible for administrators to see intuitively who has access to an account, and it also enables end
users to transition keys (and revoke compromised ones) automatically across all Monkeysphere-enabled
hosts. The User IDs and certifications that the Monkeysphere relies on are found in the OpenPGP Web of
Trust.

However, in order to establish this binding, each host must know whose cerifications to trust. Someone
who a host trusts to certify User Identities is called an Identity Certifier. A host must have at least
one Identity Certifier in order to bind User IDs to keys. Commonly, every ID Certifier would be trusted
by the host to fully identify any User ID, but more nuanced approaches are possible as well. For
example, a given host could specify a dozen ID certifiers, but assign them all "marginal" trust. Then
any given User ID would need to be certified in the OpenPGP Web of Trust by at least three of those
certifiers.

It is also possible to limit the scope of trust for a given ID Certifier to a particular domain. That
is, a host can be configured to fully (or marginally) trust a particular ID Certifier only when they
certify identities within, say, example.org (based on the e-mail address in the User ID).

KEY ACCEPTABILITY

       The  monkeysphere  commands  work  from  a  set  of user IDs to determine acceptable keys for ssh and TLS
       authentication.  OpenPGP keys are considered acceptable if the following criteria are met:

       capability
              The key must have the `authentication' (`a') usage flag set.

       validity
              The key itself must be valid, i.e. it must be well-formed, not expired, and not revoked.

       certification
              The relevant user ID must be signed by a trusted identity certifier.

HOST IDENTIFICATION

       The OpenPGP keys for hosts have associated `service names` (OpenPGP user  IDs)  that  are  based  on  URI
       specifications for the service.  Some examples:

       ssh:   ssh://host.example.com[:port]

       https: https://host.example.com[:port]

AUTHOR