In this tutorial, we are going to learn how to configure OpenLDAP password expiry email notification. If you are using identity and authentication clients such as SSSD on your OpenLDAP clients, you might have realized that, everytime you are logging into a system, SSSD displays a number of days before the password expires, that is only if the OpenLDAP password expiration policies have been implemented.
However, end users are always end users. They will always ignore these notifications. They never like the idea of changing password, :). Therefore, having different means of notifying them and even the system admins themselves about the password expiry is a great idea. This tutorial therefore will provide some basics steps to take to configure OpenLDAP to send out notifications via email to users mailbox informing them about the password expiration.
In our previous guides, we learnt how to implement OpenLDAP password policies. The link is provided below;
Implement OpenLDAP Password Policies
Similarly, we also covered how users can reset their OpenLDAP passwords by themselves using the OpenLDAP self service password tool;
Setup LDAP Self Service Password Tool on CentOS 8
Send OpenLDAP Password Expiry Notifications via Email
While scouring Internet, we came across the LDAP Tool Box (LTB), script that has been written to browse the LDAP directory to look for entries that uses password policy. If the user’s password will expire soon, a mail is sent.
The script is tested with OpenLDAP (ppolicy overlay). We provided a link to configuring password policies using the ppolicy overlay above.
Check LDAP Password Expiration Script
We downloaded the script and modified it to suit our OpenLDAP directory settings. It can sent the email notification to users whose account passwords are in warning state and at the same time, sent the statistics to a specific administrator.
Below is the contents of our modified version of the script with comment lines removed.
The original version of the script can be found at the LTB Github LDAP scripts repository.
grep -Ev "^\s[#\;]|^\s$|^#" checkLdapPwdExpiration.shMY_LDAP_HOSTURI="ldapi:///"
MY_LDAP_DEFAULTPWDPOLICYDN="cn=default,ou=pwpolicy,dc=ldapmaster,dc=kifarunix-demo,dc=com"
MY_LDAP_SEARCHBASE="ou=people,dc=ldapmaster,dc=kifarunix-demo,dc=com"
MY_LDAP_SEARCHFILTER="(&(uid=*)(objectClass=inetOrgPerson))"
MY_LDAP_SEARCHSCOPE="one"
MY_LDAP_SEARCHBIN="/usr/bin/ldapsearch"
MY_LDAP_NAME_ATTR=cn
MY_LDAP_LOGIN_ATTR=uid
MY_LDAP_MAIL_ATTR=mail
export LC_ALL=en_US.UTF-8
MY_MAIL_BODY="Hi %name,\n\n \
Your password will expire in %expireDays days on %expireTimeTZ.\n\n \
Visit Kifarunix-demo Self Service Password site, https://ldap-ssp.kifarunix-demo.com to reset your password.\n\n \
As a reminder, ensure that your password conforms to the company outlined password policies.\n\n \
Kifarunix-demo IT team,\n
Regards."
EX_MAIL_BODY="Hi %name,\n\n \
Your password expired on %expireTimeTZ.\n\n \
Kindly contact Kifarunix-demo IT team to help reset the password.\n\n \
Kifarunix-demo IT team,\n
Regards."
MY_MAIL_SUBJECT="LDAP Account Password Expiry Status"
MY_MAIL_BIN="mail"
MY_LOG_HEADER="`date +\"%b %e,%Y %T\"`"
MY_GAWK_BIN="/usr/bin/gawk"
getTimeInSeconds() {
date=0
os=`uname -s`
if [ "$1" ]; then
date=`${MY_GAWK_BIN} 'BEGIN { \
if (ARGC == 2) { \
print mktime(ARGV[1]) \
} \
exit 0 }' "$1"`
else
if [ "${os}" = "SunOS" ]; then
date=`/usr/bin/truss /usr/bin/date 2>&1 | nawk -F= \
'/^time\(\)/ {gsub(/ /,"",$2);print $2}'`
else
now=`date +"%Y %m %d %H %M %S" -u`
date=`getTimeInSeconds "$now"`
fi
fi
echo ${date}
}
tmp_dir="/tmp/$$.checkldap.tmp"
result_file="${tmp_dir}/res.tmp.1"
buffer_file="${tmp_dir}/buf.tmp.1"
tmp_dir_stats="/tmp/ldap-password-stats"
ldap_param="-Y EXTERNAL -H ${MY_LDAP_HOSTURI} -LLL -Q"
nb_users=0
nb_expired_users=0
nb_warning_users=0
if [ -d ${tmp_dir} ]; then
echo "Error : temporary directory exists (${tmp_dir})"
exit 1
fi
mkdir ${tmp_dir}
if [ ${MY_LDAP_ROOTDN} ]; then
ldap_param="${ldap_param} -D ${MY_LDAP_ROOTDN} -w ${MY_LDAP_ROOTPW}"
fi
${MY_LDAP_SEARCHBIN} ${ldap_param} -s ${MY_LDAP_SEARCHSCOPE} \
-b "${MY_LDAP_SEARCHBASE}" "${MY_LDAP_SEARCHFILTER}" \
"dn" > ${result_file}
while read dnStr
do
if [ ! "${dnStr}" ]; then
continue
fi
dn=`echo ${dnStr} | cut -d : -f 2`
nb_users=`expr ${nb_users} + 1`
${MY_LDAP_SEARCHBIN} ${ldap_param} -s base -b "${dn}" \
${MY_LDAP_NAME_ATTR} ${MY_LDAP_LOGIN_ATTR} ${MY_LDAP_MAIL_ATTR} pwdChangedTime pwdPolicySubentry \
> ${buffer_file}
login=`grep -w "${MY_LDAP_LOGIN_ATTR}:" ${buffer_file} | cut -d : -f 2 \
| sed "s/^ *//;s/ *$//"`
name=`grep -w "${MY_LDAP_NAME_ATTR}:" ${buffer_file} | cut -d : -f 2\
| sed "s/^ *//;s/ *$//"`
mail=`grep -w "${MY_LDAP_MAIL_ATTR}:" ${buffer_file} | cut -d : -f 2 \
| sed "s/^ *//;s/ *$//"`
pwdChangedTime=`grep -w "pwdChangedTime:" ${buffer_file} \
| cut -d : -f 2 | cut -c 1-15 | sed "s/^ *//;s/ *$//"`
pwdPolicySubentry=`grep -w "pwdPolicySubentry:" ${buffer_file} \
| cut -d : -f 2 | sed "s/^ *//;s/ *$//"`
if [ ! "${pwdChangedTime}" ]; then
echo "No password change date for ${login} (${mail})" >> ${tmp_dir_stats}
continue
fi
if [ ! "${pwdPolicySubentry}" -a ! "${MY_LDAP_DEFAULTPWDPOLICYDN}" ]; then
echo "No password policy for ${login} (${mail})" >> ${tmp_dir_stats}
continue
fi
ldap_search="${MY_LDAP_SEARCHBIN} ${ldap_param} -s base"
if [ "${pwdPolicySubentry}" ]; then
ldap_search="${ldap_search} -b ${pwdPolicySubentry}"
else
ldap_search="${ldap_search} -b ${MY_LDAP_DEFAULTPWDPOLICYDN}"
fi
ldap_search="$ldap_search pwdMaxAge pwdExpireWarning pwdMinLength pwdInHistory"
pwdMaxAge=`${ldap_search} | grep -w "pwdMaxAge:" | cut -d : -f 2 \
| sed "s/^ *//;s/ *$//"`
pwdExpireWarning=`${ldap_search} | grep -w "pwdExpireWarning:" | cut -d : -f 2 \
| sed "s/^ *//;s/ *$//"`
pwdMinLength=`${ldap_search} | grep -w "pwdMinLength:" | cut -d : -f 2 \
| sed "s/^ *//;s/ *$//"`
pwdInHistory=`${ldap_search} | grep -w "pwdInHistory:" | cut -d : -f 2 \
| sed "s/^ *//;s/ *$//"`
if [ ! "${pwdMaxAge}" ]; then
echo "No password expiration configured for ${login} (${mail})" >> ${tmp_dir_stats}
continue
fi
MY_MAIL_DELAY=${MY_MAIL_DELAY:=$pwdExpireWarning}
if [ "${pwdChangedTime}" ]; then
s=`echo ${pwdChangedTime} | cut -c 13-14`
m=`echo ${pwdChangedTime} | cut -c 11-12`
h=`echo ${pwdChangedTime} | cut -c 9-10`
d=`echo ${pwdChangedTime} | cut -c 7-8`
M=`echo ${pwdChangedTime} | cut -c 5-6`
y=`echo ${pwdChangedTime} | cut -c 1-4`
currentTime=`getTimeInSeconds`
pwdChangedTime=`getTimeInSeconds "$y $M $d $h $m $s"`
diffTime=`expr ${currentTime} - ${pwdChangedTime}`
fi
expireTime=`expr ${pwdChangedTime} + ${pwdMaxAge}`
if [ ${currentTime} -gt ${expireTime} ]; then
nb_expired_users=`expr ${nb_expired_users} + 1`
expireTime=`date -d @$expireTime "+%A %d, %B %Y at %T"`
logmsg="${EX_MAIL_BODY}"
logmsg=`echo -e ${logmsg} | sed "s/%name/${name}/; \
s/%login/${login}/; s/%expireTimeTZ/${expireTime}/; s/%pwdMinLength/${pwdMinLength}/; s/%pwdInHistory/${pwdInHistory}/; \
s/%expireDays/${expireDays}/"`
echo "${logmsg}" | ${MY_MAIL_BIN} -s "${MY_MAIL_SUBJECT}" ${mail} >&2
echo "Password expired for ${login} on ${expireTime}. Mail sent to ${mail}" >> ${tmp_dir_stats}
continue
fi
expireTimeTZ=`date -d @$expireTime "+%A %d, %B %Y at %T"`
expireTimeMail=`date -d @$expireTime "+%s"`
now=`date +%s`
expireDays=`echo $(( (${expireTimeMail} - ${now} )/(60*60*24) ))`
if [ "${mail}" -a "${name}" \
-a "${login}" -a "${diffTime}" -a "${pwdMaxAge}" ]
then
diffTime=`expr ${diffTime} + ${MY_MAIL_DELAY}`
if [ ${diffTime} -gt ${pwdMaxAge} ]; then
logmsg="${MY_MAIL_BODY}"
logmsg=`echo -e ${logmsg} | sed "s/%name/${name}/; \
s/%login/${login}/; s/%expireTimeTZ/${expireTimeTZ}/; s/%pwdMinLength/${pwdMinLength}/; s/%pwdInHistory/${pwdInHistory}/; \
s/%expireDays/${expireDays}/"`
echo "${logmsg}" | ${MY_MAIL_BIN} -s "${MY_MAIL_SUBJECT}" ${mail} >&2
echo "Password warning for ${login} (expiry date, ${expireTimeTZ}). Mail sent to ${mail}" >> ${tmp_dir_stats}
nb_warning_users=`expr ${nb_warning_users} + 1`
fi
fi
done < ${result_file}
sed -i "1iHello Admin,\nFind the LDAP users account password expiry status as at ${MY_LOG_HEADER}.\n" ${tmp_dir_stats}
echo "Total User Accounts checked: ${nb_users}" >> ${tmp_dir_stats}
echo "Accounts with Expired Passwords: ${nb_expired_users}" >> ${tmp_dir_stats}
echo "Accounts with Passwords in Warning state: ${nb_warning_users}" >> ${tmp_dir_stats}
sed -i -e '/^Total.*/i\\ ' -e '/^Total.*/i ===== Statistics =====' ${tmp_dir_stats}
mail -s "LDAP Password Expiration Status" [email protected] < ${tmp_dir_stats}
rm -rf ${tmp_dir}
rm -rf ${tmp_dir_stats}
exit 0
The Script Requirements
As outlined on the LTB page, the script requires;
- gawk (GNU awk) (
which gawk) - ldapsearch (
which ldapsearch) - mailx (provides mail command,
which mailx) - date (
which date)
which utility enables you to check if the command is installed and the full path to its location.
The Script Variables
Also, update the following variables on the script accordingly.
MY_LDAP_HOSTURI: LDAP URIMY_LDAP_ROOTDN(optional): DN to use to bind. No DN means anonymousMY_LDAP_ROOTPW: PasswordMY_LDAP_DEFAULTPWDPOLICYDN: Default password policy DN. Do not set if no default policy is used. In this case, the script will only affect users with password policy in their entry (pwdPolicySubentry)MY_LDAP_SEARCHBASE: Users search baseMY_LDAP_SEARCHFILTER: Users search filterMY_LDAP_SEARCHBIN: Path to ldapsearch binaryMY_MAIL_DELAY: Time before expiration where a mail is sent. No mail sent after expiration. If no value, the script will take the pwdExpireWarning of the password policyMY_LDAP_NAME_ATTR: attribute containing user’s nameMY_LDAP_LOGIN_ATTR: attribute containing user’s loginMY_LDAP_MAIL_ATTR:attribute containing user’s nameMY_MAIL_BODY: message bodyMY_MAIL_SUBJECT: message subjectMY_MAIL_BIN: mail binaryMY_LOG_HEADER: log headerMY_GAWK_BIN: path to gawk binary
Sample LDAP User entry
Below is our sample OpenLDAP user entry. Note the following attributes;
MY_LDAP_NAME_ATTR=cnMY_LDAP_LOGIN_ATTR=uidMY_LDAP_MAIL_ATTR=mail
ldapsearch -Y EXTERNAL -H ldapi:/// -s one -b "ou=people,dc=ldapmaster,dc=kifarunix-demo,dc=com" -LLL -Q uid=janedoe dn: uid=janedoe,ou=people,dc=ldapmaster,dc=kifarunix-demo,dc=com
objectClass: inetOrgPerson
objectClass: posixAccount
objectClass: shadowAccount
objectClass: extensibleObject
uid: janedoe
cn: Jane
sn: Doe
loginShell: /bin/bash
uidNumber: 10010
gidNumber: 10010
homeDirectory: /home/janedoe
shadowMax: 60
shadowMin: 1
shadowWarning: 7
shadowInactive: 7
shadowLastChange: 0
userPassword:: e1NTSEF9dmczUGpBa0EybUtOanJ4QWc1dWN5d20wNnlmOGg4cE8=
mail: [email protected]
Testing the LDAP Password Expiration Notification Script
To check the script can get us what is expected of it, simply execute it on the LDAP server as follows;
bash checkLdapPwdExpiration.shOur script writes output to, /tmp/ldap-password-stats, file.
cat /tmp/ldap-password-statsHello Admin,
Find the LDAP users account password expiry status as Jun 13,2020 21:19:18.
Password warning for janedoe (expiry date, Thursday 18, June 2020 at 11:12:37). Mail sent to [email protected]
Password expired for koromicha on Friday 08, May 2020 at 21:34:02. Mail sent to [email protected]
No password change date for johndoe ([email protected])
===== Statistics =====
Total User Accounts checked: 4
Accounts with Expired Passwords: 1
Accounts with Passwords in Warning state: 1
From the output above, we can see that;
- A total of fours users, in the directory, were checked.
- Password for user
koromicha, has expired on Friday 08, May 2020 at 21:34:02. Notification email sent to user. - Password for the user,
janedoe, will expire on Thursday 18, June 2020 at 11:12:37. Notification email sent to user. - No password change date for johndoe ([email protected])
Since we do not have any mail utility installed, you may get such an output;
mail: command not foundConfigure your LDAP Server to Send Mails
In order for your OpenLDAP server to be able to send mails out, you need to have an MTA installed and configured. If you noticed above, the script tried use sendmail. In this demo, we will be using postfix instead.
Note that our LDAP server is running on a CentOS 8 system
Install and Setup OpenLDAP on CentOS 8
Install Postfix MTA on CentOS 8
yum install postfix cyrus-sasl-plain mailxConfigure Postfix to use Gmail SMTP relay
cp /etc/postfix/main.cf /etc/postfix/main.cf.oldvim /etc/postfix/main.cfMake the following adjustments;
myhostname = ldap.kifarunix-demo.cominet_protocols = ipv4relayhost = [smtp.gmail.com]:587smtp_use_tls = yessmtp_sasl_auth_enable = yessmtp_sasl_password_maps = hash:/etc/postfix/sasl_passwdsmtp_sasl_security_options = noanonymousSave and exit the configuration.
Enter the authentication credentials on the file, /etc/postfix/sasl_passwd in the format;
[smtp.gmail.com]:587 userid@gmail:passwordHash the credentials file.
postmap /etc/postfix/sasl_passwdSet the proper permissions on the credentials file,
chown root:postfix /etc/postfix/sasl_passwd*
chmod 640 /etc/postfix/sasl_passwd*Start the Postfix configuration.
systemctl enable --now postfixTest Email Delivery
echo "Test Postfix gmail relay" | mail -s "Test postfix gmail relay" [email protected]Check the logs.
tail /var/log/maillogIf you see this line, all is well;
[email protected], relay=smtp.gmail.com[74.125.133.108]:587, ...status=sent (250 2.0.0 OK ..Once the email relay configuration is done, rerun the script.
bash checkLdapPwdExpiration.shCheck the administrator inbox, which in this demo is set to, [email protected], and the inbox for the user whose password is in warning state, [email protected].
On Admin Mailbox, this is the email from LDAP;
Subject: LDAP Password Expiration Status
Hello Admin,
Find the LDAP users account password expiry status as Jun 13,2020 21:31:11.
Password warning for janedoe (expiry date, Thursday 18, June 2020 at 11:12:37). Mail sent to [email protected]
Password expired for koromicha on Friday 08, May 2020 at 21:34:02. Mail sent to [email protected]
No password change date for johndoe ([email protected])
===== Statistics =====
Total User Accounts checked: 4
Accounts with Expired Passwords: 1
Accounts with Passwords in Warning state: 1
On the User’s inbox (Janedoe and Koromicha in this case);
Subject: LDAP Account Password Expiry Status
Hi jane,
Your password will expire in 4 days on Thursday 18, June 2020 at 11:12:37.
Visit Kifarunix-demo Self Service Password site, https://ldap-ssp.kifarunix-demo.com to reset your password.
As a reminder, ensure that your password conforms to the company outlined password policies.
Kifarunix-demo IT team,
Regards.
Subject: LDAP Account Password Expiry Status
Hi koromicha,
Your password expired on Friday 08, May 2020 at 21:34:02.
Kindly contact Kifarunix-demo IT team to help reset the password.
Kifarunix-demo IT team,
Regards.
And there you go. You are now receiving the status of the LDAP accounts password expiry as the administrator. At the same time, users whose passwords are yet to expire are notified via their respective emails as defined on their LDAP entries. We hope that was informative.
Create Daily Cron Job for the Script
To ensure that the script is executed regularly, all you need to do is to create a cron job to execute the script at a specific regular time and have the LDAP accounts passwords status sent to users.
Before you can install a cron job, ensure that the script is executable.
chmod +x /home/kifarunix/checkLdapPwdExpiration.shTo install a cron job, run the command below;
crontab -eEnter the line below, to have the script executed every day from Monday-Friday at 0800 hrs.
0 8 * * 1-5 /home/kifarunix/checkLdapPwdExpiration.shThat marks the end of our guide on how to send OpenLDAP password expiry notifications via email.
Related Tutorials
Configure Offline Authentication via OpenLDAP on MacOS X
Install and Setup OpenLDAP Server on Ubuntu 20.04
