Overview of CyLogin

Documentation / Contents - CyLogin

• Overview of CyLogin
  • What It Is
  • What It Is Not
  • The Programs
  • In This Book
• Setting Up
  • What You Need
  • Build and Install
  • Enable With the Helper
  • Linux SysV and systemd
  • NetBSD rc.d
  • PAM Service File
  • Xservers and VT
  • Headless and LXC
  • Competing Display Managers
  • Check That It Works
  • Disable and Rollback
  • Common Mistakes
• Using CyLogin
  • Logging In
  • Faces
  • noiconlogin
  • Session Lock
  • Autologin and Classroom
  • After Login (Session)
  • Failsafe
• Configuration
  • Master Conf
  • Appearance
  • Session Path
  • Unsafe Knobs
  • Autologin Knobs
  • Lock Timeout
  • Classroom Sample
• Enable and Disable Helpers
  • cylogin-enable
  • Every enable Flag
  • cylogin-disable
  • Examples
• Security and PAM
  • Defaults
  • PAM Stacks
  • Empty Password Gate
  • Auth Dir and Cookies
  • Vs XDM and login
  • Lab Matrix
• Command Line
  • cylogind
  • cylogin Greeter
  • cylogin-authcheck
  • cychooser
• Keys and Shortcuts
• Files and Paths
  • System Conf
  • Runtime
  • Share Install
  • Init and PAM
• Troubleshooting
  • Greeter Never Appears
  • No Screens Found
  • PAM Failures
  • Wrong Session After Login
  • Setuid and Nobody
• Copyright

CyLogin

CyLogin is the graphical login for Cyanotype Blueprint. It replaces xdm (and friends) on the local seat: start X, show a Motif greeter, authenticate, then start a session. Under cylogind the greeter speaks a PAM-shaped conversation on fd 3 and authentication is live. Standalone it is a face-only picker with no auth and no session.

Open this book from Help Books in the Contents pane as "CyLogin", from the greeter Help button, or:

cyhelp --book CyLogin --topic overview

The page most admins need first is Setting Up. Day-to-day greeter use is in Using CyLogin. Every helper flag is in Enable and Disable Helpers.

What It Is

• A Motif greeter (cylogin / cylogin-greeter) in the clogin tradition: face grid or typed name, then password when required.
• A display manager (cylogind) that owns local X servers from Xservers, mint cookies, run hooks, and start sessions.
• A setuid helper (cylogin-authcheck) that verifies the password for the real uid on the lock path, and PAM service name cylogin on Linux.
• Enable/disable helpers so you can claim or leave the console seat without hand-editing half a dozen paths.
• Optional XDMCP when you turn it on (UDP 177); not the default lab path.

What It Is Not

• Not a Wayland greeter and not a nested remote desktop.
• Not LightDM/GDM/SDDM with a Cyanotype skin. CyLogin is its own DM.
• Not an invitation to walk-in null passwords or root at the greeter. Those knobs exist for demos and stay off by default.
• Helpers do not invent a _cylogin account. Default greeter_user is nobody.

The Programs

cylogind            display manager (root); never opens an X display itself
cylogin-greeter     Motif face (also installed as cylogin)
cylogin-authcheck   setuid root helper for lock-path password verify
cychooser           XDMCP chooser face (when XDMCP is in play)
cylogin-enable      claim the seat: PAM, conf, init/rc, stop old DM
cylogin-disable     stop CyLogin; best-effort restore previous DM file

Man pages: man cylogind, man cylogin. Interim how-to: share/cylogin/README.md. Security notes: src/cylogin/docs/security.md.

In This Book

• Setting Up -- build, enable helper, Linux, NetBSD, PAM, Xservers, headless/LXC dummy seat, rollback
• Using CyLogin -- login, faces, lock, autologin, session path
• Configuration -- every cylogin.conf knob that matters
• Enable and Disable Helpers -- every flag with examples
• Security and PAM -- stacks, nullok gate, cookies, vs XDM
• Command Line -- cylogind, greeter, authcheck
• Keys and Shortcuts
• Files and Paths
• Troubleshooting

Related On This Desktop

• CyScreen / cysaver dismisses into cylogin --lock for unlock.
• startcyanotype.sh is the usual Blueprint session after login.
• In the Blueprint book, Settings Books lists desktop programs; CyLogin is the console door, not a prefs panel.