You have some other options to solve that:
- SSH Key management with SKM
- SSH Key DB
- Openssh LPK (SSH Patch that supports LDAP)
- Openssh Ldap Publickey
I believe that Openssh Ldap Publickey is one of the best options cause it does not require any patches or file syncing and it keeps the public keys in a central LDAP server.
1. https://sites.google.com/site/jeromeboismartel/code-s-corner... 2. https://code.google.com/p/ssh-keydb/ 3. https://code.google.com/p/openssh-lpk/ 4. https://github.com/AndriiGrytsenko/openssh-ldap-publickey