Information
Password complexity can be set through:
- minclass - The minimum number of classes of characters required in a new password. (digits, uppercase, lowercase, others). e.g. minclass = 4 requires digits, uppercase, lower case, and special characters.
- dcredit - The maximum credit for having digits in the new password. If less than 0 it is the minimum number of digits in the new password. e.g. dcredit = -1 requires at least one digit
- ucredit - The maximum credit for having uppercase characters in the new password. If less than 0 it is the minimum number of uppercase characters in the new password. e.g. ucredit = -1 requires at least one uppercase character
- ocredit - The maximum credit for having other characters in the new password. If less than 0 it is the minimum number of other characters in the new password. e.g. ocredit = -1 requires at least one special character
- lcredit - The maximum credit for having lowercase characters in the new password. If less than 0 it is the minimum number of lowercase characters in the new password. e.g. lcredit = -1 requires at least one lowercase character
Strong passwords protect systems from being hacked through brute force methods.
Solution
Edit /etc/security/pwquality.conf and add or modify the following line to set:
minclass = 4
--AND/OR--
dcredit = -_N>
ucredit = <N>
ocredit = <N>
lcredit = <N>
Example:
# printf '
%s' "minclass = 4" >> /etc/security/pwquality.conf
--AND/OR--
# printf '%s
' "dcredit = -1" "ucredit = -1" "ocredit = -1" "lcredit = -1" >> /etc/security/pwquality.conf
Run the following script to remove setting minclass dcredit ucredit lcredit and ocredit on the pam_pwquality.so module in the PAM files
#!/usr/bin/env bash
{
for l_pam_file in system-auth password-auth; do
sed -ri 's/(^s*passwords+(requisite|required|sufficient)s+pam_pwquality.so.*)(s+minclasss*=s*S+)(.*$)/14/' /etc/pam.d/"$l_pam_file"
sed -ri 's/(^s*passwords+(requisite|required|sufficient)s+pam_pwquality.so.*)(s+dcredits*=s*S+)(.*$)/14/' /etc/pam.d/"$l_pam_file"
sed -ri 's/(^s*passwords+(requisite|required|sufficient)s+pam_pwquality.so.*)(s+ucredits*=s*S+)(.*$)/14/' /etc/pam.d/"$l_pam_file"
sed -ri 's/(^s*passwords+(requisite|required|sufficient)s+pam_pwquality.so.*)(s+lcredits*=s*S+)(.*$)/14/' /etc/pam.d/"$l_pam_file"
sed -ri 's/(^s*passwords+(requisite|required|sufficient)s+pam_pwquality.so.*)(s+ocredits*=s*S+)(.*$)/14/' /etc/pam.d/"$l_pam_file"
done
}