Your own ID-Server
On premise installations of SecSign ID offer the flexibility to connect with your preferred servers, services, and devices. And you can customize the SecSign ID with your own organization’s branding.
Learn MoreSecSign ID Plugin: Linux Desktop Login
2017-07-31
5 minutes to read
Tutorial Index
Two-Factor Authentication for Linux Desktop Login
The Pluggable Authentication Modules (PAM) is a software library which offers a general programming interface for authentication services. By using the PAM-API one does no longer need to define the settings for every single authentication application. Instead, individual standardized modules can be used. The modules can be assigned to individual services in the configuration file. There is no need to change the compilation of the corresponding software. PAM is available for AIX, HP-UX, Solaris, Linux, FreeBSD, NetBSD, Mac OS X and DragonFly BSD.
PAM Overview
Integration
Integration of the plugin into your setup
edit the settings to change the integration
Authentication
2FA
2FA blind
2FA no AP
2SA
2SA no AP
2SA blind
OTP
Enrollment
Custom ID
Pattern
IDP Custom Website
IDP Email Enrollement Code
Enrollment initiated by SP
Enrollment with IDM
Installation
Installation of the plugin
Please read the SecSign ID PAM Tutorial before using the SecSign ID PAM for Linux Desktop Authentication. Follow steps 3 to 5 to configure and install PAM correctly.
Configuration
Configuration of the plugin
In this example, we use the Ubuntu flavor. To add two-factor authentication to the graphical login, open the configuration file /etc/pam.d/lightdm and activate the utilization of the SecSignID PAM:
auth required pam_secsignid.so nullok
Save the file and reboot the SSH server with
sudo service ssh restart
Log out and try the SecSign ID Two-Factor Authentication.
Troubleshooting
Troubleshooting
Compilation errors
The library libcurl needs to be installed in the standard path, otherwise make fails. If libcurl is not on the standard path the compilation needs to be executed manually.
Authentication errors
If the authentication fails the debug- and logmodus should be activated (see PAM debug- and logmodus) and the output should be written in a file. This is necessary since PAM normally needs to be silent and does not allow for output for security reasons. If no log- or debug-files are generated the paths provided in secsignid.c are incorrect or no read-and-write authorizations are available.
A log-file is produced stating all errors. It is determined if libcurl works accurate, if the SecSign ID server is available, if port 443 is available to communicate with the server, if the configuration file is available and if PAM has reading authorization.
A debug file is created which records the interface communication. It is determined wether errors in the communication persists because no SecSign ID for the specific user was found or if there are errors in a different parameter, for example the service name.
Deactivate
Because we just enabled the 2FA for graphical logins, it should be easy to disable if it causes a problem. Press a key combination like Ctrl + Alt + F2 to access a virtual terminal and log in there with your username and password. You can then use a command like
sudo nano /etc/pam.d/lightdm
to open the file for editing in a terminal text editor. Save the file and you’ll be able to log in normally again.
