Free and open source disk encryption software. More information: https://www.veracrypt.fr/code/VeraCrypt/plain/doc/html/Documentation.html.
/dev/urandom
as a source of random data:veracrypt --text --create --random-source=/dev/urandom
veracrypt --text path/to/volume path/to/mount_point
veracrypt --keyfiles=path/to/keyfile /dev/sdXN path/to/mount_point
veracrypt --dismount path/to/mounted_point