Binary package “libpam-fscrypt” in ubuntu bionic

PAM module for Linux filesystem encryption

 fscrypt is a high-level tool for the management of Linux filesystem
 encryption. This tool manages metadata, key generation, key wrapping, PAM
 integration, and provides a uniform interface for creating and modifying
 encrypted directories.
 .
 This PAM module can be used to unlock one or more directories upon user login
 and then lock those directories when the user ends their session.