On 7/21/12 3:39 PM, Florian Bilek wrote:

> 2.) In principle the login via SSH is working very good. I encountered
> recently a kind of weakness in the configuration: A RACF user that uses its
> own RSA keys to log into the system. When I do a RACF revoke on that user,
> it seems that the LDAP check not takes place and the user can still login.
> What can be done about that?

Ssh apparently bypasses the pam "auth" step if it has a ssh key match.

Perhaps experiment by adding a pam "account" or pam "session" step which
refers to pam_ldap?  I'm unclear if the pam_ldap module supports these
steps, though, the documentation is unclear.

One other useful pam module which may apply here is "pam_access".
Pam_access does explicitly support the "account" and "session" module
types, and it's quite flexible.  You might be able to craft an e.g.
"denied_users" group which would deny access to any member of that group.

One final thought, I seem to recall there's patches flying around which
allow ssh public keys to be stored in LDAP.  Perhaps investigate this
idea.  If pubkeys could only be in a user's LDAP entry, then as part of
a revoke process, these keys could be removed.   Google "ssh public key
ldap"

Hope that helps,

-- Pat

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