Pam_p11 is a plugable authentication module (pam) package
for using crpytographic tokens such as smart cards and
usb crypto tokens for authentication.

Pam_p11 uses libp11 to access any PKCS#11 module.
It should be compatible with any implementation, but it
is primarely developed using OpenSC.

Pam_p11 implements two authentication modules:
 * pam_p11_openssh authenticates the user using his
   openssh ~/.ssh/authorized_keys file.
 * pam_p11_opensc authenticates the user using
   certificates found in ~/.eid/authorized_certificates.

Pam_p11 is very simple, it has no config file, no options
other than the PKCS#11 module file, does not know about
certificate chains, certificate authorities, revocation
lists or OCSP. Perfect for the small installation with no
frills.

WWW: https://github.com/OpenSC/OpenSC/wiki/pam_p11-simple-RSA-authentication-with-PKCS%2311-modules