SSH Access Manager allows you to maintain user public keys. You can organise these keys with group of keys called keyring. Then SSH Access Manager will deploy the keys and/or keyrings to specified unix accounts / groups / servers.
User can be read from a LDAP directory.
Key Manager is designed to allow distribution and management of SSH keys in a way that scales beyond manually copying public keys to remote hosts. This approaches Single-Sign-On functionality, if limited to ssh access from a single host.