Troubleshooting User Guide for Troubleshooting PAM Authentication Issues in Posit Workbench

PAM
Workbench
authentication
Published

January 29, 2026

Abstract

This guide provides steps to troubleshoot and resolve PAM authentication issues encountered while setting up Posit Workbench.

Overview

When setting up Posit Workbench, users may encounter issues related to PAM (Pluggable Authentication Module) authentication. This guide outlines common troubleshooting steps to help resolve these issues.

Steps to Troubleshoot PAM Authentication

Verify PAM Configuration

  • Ensure that the PAM profile /etc/pam.d/rstudio is correctly configured. You may need to customize it further if the default settings do not match your authentication requirements.
  • Check if the pam_rootok.so directive is correctly placed in the PAM profile, as it allows root authentication without a password.

Check rserver.conf Settings

  • If restricting access by group, ensure that the auth-required-user-group=<value> setting in the rserver.conf file is correct and that all users needing access are part of the group.
  • Verify the auth-pam-require-password-prompt setting. If using a nonstandard password prompt, disable strict prompt matching by setting auth-pam-require-password-prompt=0.

Use pamtester for Diagnostics

  • The pamtester utility can help diagnose PAM configuration issues. Run it with verbose output to get detailed diagnostics:

    Terminal
    sudo /usr/lib/rstudio-server/bin/pamtester --verbose rstudio <username> authenticate

  • Ensure that the username used in pamtester matches the format expected by your PAM configuration.

Review Encryption Settings

  • The error message may indicate a problem with padding mode during encryption. Verify that your system’s encryption settings are compatible with Workbench’s requirements.

Consult Documentation

Check System Authentication Logs

  • Review the system authentication logs, typically found at /var/log/auth.log or /var/log/secure, for any error messages related to PAM.

Network and Proxy Settings

  • If using a proxy, ensure that the proxy settings are correctly configured in the Workbench environment. You can check the proxy settings in the /etc/rstudio/rserver.conf file.

Additional Considerations

  • If FIPS mode is enabled, it may cause compatibility issues with certain encryption methods used by Workbench. Consider disabling FIPS mode if necessary, but be aware of potential security implications.

Conclusion

By following these troubleshooting steps, users should be able to resolve common PAM authentication issues encountered while setting up Posit Workbench.

If you’re still having issues, you can reach out to Support by opening a ticket.