PKCS#11 is a standard API to interface with HSMs, Smart Cards, or other types of random hardware backed crypto. On my travel laptop, I use a few Yubikeys in PKCS#11 mode using OpenSC to handle system login. libpam-pkcs11 is a pretty easy to use module that will let you log into your system locally using a PKCS#11 token locally.

One of the least documented things, though, was how to use an OpenSC PKCS#11 token in Chrome. First, close all web browsers you have open.

sudo apt-get install libnss3-tools

certutil -U -d sql:$HOME/.pki/nssdb
modutil -add "OpenSC" -libfile /usr/lib/x86_64-linux-gnu/opensc-pkcs11.so -dbdir sql:$HOME/.pki/nssdb
modutil -list "OpenSC" -dbdir sql:$HOME/.pki/nssdb 
modutil -enable "OpenSC" -dbdir sql:$HOME/.pki/nssdb

Now, we’ll have the PKCS#11 module ready for nss to use, so let’s double check that the tokens are registered:

certutil -U -d sql:$HOME/.pki/nssdb
certutil -L -h "OpenSC" -d sql:$HOME/.pki/nssdb

If this winds up causing issues, you can remove it using the following command:

modutil -delete "OpenSC" -dbdir sql:$HOME/.pki/nssdb