I'm trying to configure some Red Hat/CentOS servers to use an ipa-server on CentOS 6 for SSH authentication with public keys. I'm storing the public keys on the IPA server, which works great on Centos6 using "AuthorizedKeysCommand /usr/bin/sss_ssh_authorizedkeys" in /etc/ssh/sshd_config. However, on RH 5.10, neither the "AuthorizedKeysCommand" directive or the "/usr/bin/sss_ssh_authorizedkeys" command exist to pull the public key from the directory. Is there a different way to make this work? Googling this mostly returns instructions for setting it up on 6.
Did you try to install 'sssd' package on RHEL 5.10?
yum install sssd
That package will install 'sss_ssh_authorizedkeys' binary.
If the package doesn't exist in RHEL repositories for 5.10 you can safely use the CentOS RPM because they are binary compatible distros.