Skip to content
ATO Pathways
  Log In

Set Password Hashing Rounds in /etc/login.defs

An XCCDF Rule

Description

In /etc/login.defs, ensure SHA_CRYPT_MIN_ROUNDS and SHA_CRYPT_MAX_ROUNDS has the minimum value of 5000. For example: 

SHA_CRYPT_MIN_ROUNDS 5000
SHA_CRYPT_MAX_ROUNDS 5000
Notice that if neither are set, they already have the default value of 5000. If either is set, they must have the minimum value of 5000.

Rationale

Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text.

Using more hashing rounds makes password cracking attacks more difficult.

ID
xccdf_org.ssgproject.content_rule_set_password_hashing_min_rounds_logindefs
Severity
Medium
References
Updated



Remediation - Ansible

- name: Set Password Hashing Rounds in /etc/login.defs - Ensure SHA_CRYPT_MIN_ROUNDS
    has Minimum Value of 5000
  ansible.builtin.replace:
    path: /etc/login.defs
    regexp: (^\s*SHA_CRYPT_MIN_ROUNDS\s+)(?!(?:[5-9]\d{3,}|\d{5,}))\S*(\s*$)
    replace: \g<1>5000\g<2>

Remediation - Shell Script


if [ -e "/etc/login.defs" ] ; then
    
    LC_ALL=C sed -i "/^\s*SHA_CRYPT_MIN_ROUNDS\s*/Id" "/etc/login.defs"
else
    printf '%s\n' "Path '/etc/login.defs' wasn't found on this system. Refusing to continue." >&2