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+---
+project: cac-manjaro-thinkpad
+type: tech-setup
+status: completed
+path: Tech/Sessions
+tags:
+  - cac
+  - manjaro
+  - thinkpad
+  - pcscd
+  - opensc
+  - firefox
+created: 2026-04-15
+updated: 2026-04-15
+---
+
+# CAC Setup — Manjaro ThinkPad
+
+## Overview
+
+CAC authentication configured and working on Manjaro ThinkPad using
+OpenSC + pcscd. Tested against Office 365 / DoD sites via Firefox.
+
+## Stack
+
+- **Middleware:** pcscd (pcsc-lite)
+- **PKCS#11 module:** OpenSC — `/usr/lib/opensc-pkcs11.so`
+- **Browser:** Firefox
+- **Test tool:** pcsc_scan (pcsc-tools)
+
+## Working Session Flow
+
+1. Ensure pcscd is running:
+   ```bash
+   sudo systemctl start pcscd
+   ```
+
+2. Verify card is detected (keep running in terminal):
+   ```bash
+   pcsc_scan
+   ```
+   Confirm reader and card state are both visible before proceeding.
+
+3. Open Firefox and navigate to CAC-protected site — certificate
+prompt should appear.
+
+## Firefox PKCS#11 Module
+
+One-time setup (persists across sessions, but may reset after Firefox updates):
+
+1. Firefox → Preferences → Privacy & Security
+2. Scroll to **Security** section → click **Security Devices**
+3. Click **Load**
+4. Module name: `DoD CAC`
+5. Module filename: `/usr/lib/opensc-pkcs11.so`
+
+> **Note:** Firefox updates have been observed to clear this setting. If CAC auth stops working after a Firefox update, re-load the module using the steps above before troubleshooting anything else.
+
+## Enable pcscd on Boot
+
+Run once so the daemon starts automatically — eliminates step 1 above
+on future sessions:
+
+```bash
+sudo systemctl enable pcscd
+```
+
+## Troubleshooting
+
+| Symptom | Fix |
+|---|---|
+| `pcsc_scan` shows no reader | Check USB connection, try `sudo
+systemctl restart pcscd` |
+| Reader visible but card not detected | Remove and reinsert CAC |
+| Firefox not prompting for cert | Re-load OpenSC module in Security
+Devices (see above) |
+| pcscd daemon crashed | `sudo systemctl restart pcscd`, then re-run
+`pcsc_scan` |
+
+## References
+
+- https://militarycac.com/linux.htm
+- https://wiki.archlinux.org/title/Common_Access_Card
+- https://github.com/jdjaxon/linux_cac
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