Common Access Card

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Revision as of 10:35, 5 September 2013 by Cceleri (Talk | contribs) (Software Installation)

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This page explains how to setup Arch to use a US Department of Defense Common Access Card (CAC). It was tested with an SCR331 USB card reader which is a very common one. Others may work...or not.


The following packages should be installed from [community]:

Enable pcscd

$ sudo systemctl enable pcscd
$ sudo systemctl start pcscd

Configure browser


Navigate to Edit -> Preference -> Advanced -> Certificates -> Security Devices and load a module using /usr/lib/

Configuring Firefox

Enabling Firefox to use the CAC Reader

Insert CAC into reader - the green light should flash on the SCR331.

Add CAC Reader to Firefox as a Security Device

  1. Go to Edit->Preferences on the toolbar.
  2. Click on Advanced
  3. Click on the Encryption Tab
  4. Click on the Security Devices Button
  5. Click on the Load Button
  6. Enter CAC Reader as the module name, and browse to /usr/local/lib/ then click Open.

Importing the DoD Certificates

If you have installed the DoD Configuration extension for Firefox you can use it to import the appropriate certificates.

Tools > Addons > Extensions > DoD Configuration > Preferences

If you're using a branded version of Firefox you should be able to go to and click on the high-level certificates to install them and be done.

If you're using Namoroka this site will not recognize it as Firefox and simply clicking on the link above will not get you into the site. You can work around this problem (which affects some other websites too) by changing Namoroka's configuration a little.

  1. Open a new tab in Namoroka
  2. Type about:config in the address bar and press enter
  3. Type 'useragent' in the search box
  4. Double-click on the value where you see "Namoroka"
  5. Change "Namoroka" to "Firefox"
  6. Close the tab

Once you get into the site, you can download the certificates by following the directions on the page.

The primary root certificate used has a CN of "DoD Root CA 2": this certificate can be converted to PEM format for use in other browsers:

  1. Download the CA bundle. This includes approximately 36 certificates. $ curl -O
  2. Extract the root certificate into a PEM-formatted file.

$ openssl pkcs7 -inform DER -in rel3_dodroot_2048.p7b -print_certs | sed -n '/subject=.*CN=DoD Root CA 2/,${/^$/q;P;D}' > DoD_Root_CA_2.pem


Visit your favorite CAC secured web page and you should be asked for the Master Password for your certificate. Enter it and if you get in, you know it's working.