# Then append the following line to /etc/sudoers (use `sudo vi /etc/sudoers`)
Defaults env_keep += SSH_AUTH_SOCK
# And add the following line to /etc/pam.d/sudo just above the @include lines.
# Change the 3 in 'success=3' to the number of @include lines you see in that file.
$ TEMP_DIR=/tmp/del_pam_sudo
$ mkdir -p $TEMP_DIR
$ cd $TEMP_DIR
$ wget "http://downloads.sourceforge.net/project/pamsshagentauth/pam_ssh_agent_auth/v0.9.3/pam_ssh_agent_auth-0.9.3.tar.bz2"
$ tar -xjvf pam_ssh_agent_auth-0.9.3.tar.bz2
$ cd pam_ssh_agent_auth-0.9.3
# If the following command fails then you have to apply the patch available here:
# https://sourceforge.net/tracker/?func=detail&aid=3510464&group_id=249556&atid=1126337
$ dpkg-buildpackage -rfakeroot
$ cd $TEMP_DIR
$ sudo dpkg -i pam-ssh-agent-auth_0.9.3-1_amd64.deb
# Then append the following line to /etc/sudoers (use `sudo vi /etc/sudoers`)
Defaults env_keep += SSH_AUTH_SOCK
# And add the following line to /etc/pam.d/sudo just above the @include lines.
# Change the 3 in 'success=3' to the number of @include lines you see in that file.
auth pam_ssh_agent_auth.so file=~/.ssh/authorized_keys
If you don't want to build:
$ wget https://launchpad.net/~dbanck/+archive/server/+files/pam-ssh-agent-auth_0.9.3-1ubuntu1_amd64.deb
$ sudo dpkg -i pam-ssh-agent-auth_0.9.3-1ubuntu1_amd64.deb