A client was concerned that their password hash was MD5. A check of the /etc/shadow file showed: user:$6$UAxaIY9I$hAkj …   The first field annotated by a ‘$’ (: is the delimiter) is 6 = SHA256 (1 = MD5) And /etc/pam.d/common-password specifies it: ​ password        [success=1 default=ignore]      pam_unix.so obscure use_authtok try_first_pass[…]