Jump to: navigation, search

IPA 2x Certificate Renewal

Introduction

Automated certificate renewal of the CA subsystem certificates was added in IPA 3.0. If you can't upgrade, here are some manual steps that should get you moving forward.

You probably have several certificates tracked by certmonger in a CA_UNREACHABLE state, like:

Request ID '20111111152846':
        status: CA_UNREACHABLE
        ca-error: Server failed request, will retry: -504 (libcurl failed to execute the HTTP POST transaction.  Peer certificate cannot be authenticated with known CA certificates).
        stuck: yes
        key pair storage: type=NSSDB,location='/etc/httpd/alias',nickname='Server-Cert',token='NSS Certificate DB',pinfile='/etc/httpd/alias/pwdfile.txt'
        certificate: type=NSSDB,location='/etc/httpd/alias',nickname='Server-Cert',token='NSS Certificate DB'
        CA: IPA
        issuer: CN=Certificate Authority,O=EXAMPLE.COM
        subject: CN=ipa.example.com,O=EXAMPLE.COM
        expires: 2013-11-11 15:28:46 UTC
        eku: id-kp-serverAuth,id-kp-clientAuth
        pre-save command: 
        post-save command: /usr/lib64/ipa/certmonger/restart_httpd
        track: yes
        auto-renew: yes

Process

Important.png
Manual Process
This is a very manual process. Be sure you understand all the steps before proceeding. This is why this is automated in 3.0+

The first thing you need to do is update certmonger to at least 0.58-1:

# yum update certmonger

This provides the dogtag-ipa-renew-agent CA that can directly renew the dogtag CA subsystem certificates. You only need to do this on those masters with a CA (so it won't hurt if you upgrade it in other places too but it won't help with this problem either).

In order for this to work you are going to need to go back in time to when the certificates are all still valid. First we need to stop the NTP service:

# /sbin/service ntpd stop

To find out when the certificates were still valid, run:

 # for nickname in "auditSigningCert cert-pki-ca" "ocspSigningCert cert-pki-ca" "subsystemCert cert-pki-ca" "Server-Cert cert-pki-ca"
   do
     echo $nickname
     certutil -L -d /var/lib/pki-ca/alias -n "${nickname}" | grep -i after
   done

This tells us when to set time back to. I recommend setting time back at least 24 hours before expiration.

Next, you need to determine the PIN for the CA NSS database:

# grep internal= /var/lib/pki-ca/conf/password.conf

Now we need to tell certmonger about all the CA certificates it needs to renew

# for nickname in "auditSigningCert cert-pki-ca" "ocspSigningCert cert-pki-ca" "subsystemCert cert-pki-ca" "Server-Cert cert-pki-ca"
 do
     /usr/bin/getcert start-tracking -d /var/lib/pki-ca/alias -n "${nickname}" -c dogtag-ipa-renew-agent -P <internal pin>
 done

We also need to renew the agent certificate that IPA uses to authenticate:

 # /usr/bin/getcert start-tracking -d /etc/httpd/alias -n ipaCert -c dogtag-ipa-renew-agent -p /etc/httpd/alias/pwdfile.txt

Use "getcert list" to confirm that these 5 certs are now being tracked and note the Request IDs. You should be tracking a total of 8 certificates now.

Now it's time to go back in time to when the certificates are valid, something like:

# date 102910262013

Let's force renewal on all of the certificates:

# for line in `getcert list | grep Request | cut -d "'" -f2`; do getcert resubmit -i $line; done

This will renew the CA subsystem certificates but the server certificates for Apache and 389-ds will have failed. We need to do a little more work to get those renewed, and to get the CA fully operational again.

Running getcert list should confirm this. The two 389-ds and the Apache certs are still in CA_UNREACHABLE, though the reason is now SSL peer rejected your certificate as expired.

Let's continue getting the CA up and running. The audit subsystem certificate is recreated with the wrong trust permissions. To fix this run:

# certutil -M -n "auditSigningCert cert-pki-ca" -d /var/lib/pki-ca/alias -t u,u,Pu 

The dogtag configuration file has a base64-encoded copy of most of these certificates in it. You'll need to update those by hand.

To get this run:

# for nickname in "auditSigningCert cert-pki-ca" "ocspSigningCert cert-pki-ca" "subsystemCert cert-pki-ca" "Server-Cert cert-pki-ca"; do certutil -L -d /var/lib/pki-ca/alias -n "${nickname}" -a > /tmp/"${nickname}"; done

Stop the CA service:

# /sbin/service pki-cad stop

Then edit /etc/pki-ca/CS.cfg and find the cert entry for each one and replace the blobs. The option names are like ca.audit_signing.cert, ca.ocsp_signing.cert, etc. It should be fairly straightforward. There are 4 certs you need to replace.

Here are the nicknames and values:

'auditSigningCert cert-pki-ca': 'ca.audit_signing.cert'
'ocspSigningCert cert-pki-ca': 'ca.ocsp_signing.cert'
'subsystemCert cert-pki-ca': 'ca.subsystem.cert'
'Server-Cert cert-pki-ca': 'ca.sslserver.cert'

The PEM exported by certutil is going to be broken into several 64-character lines. You will need to combine them into a single line.

Backing up this file in advance would be a good idea.

Now you can try to restart the CA to see what happens. It should come up fine:

# /sbin/service pki-cad start

For ipaCert, stored in /etc/httpd/alias you have another job to do. This certificate is used to authenticate with the CA. You'll need to use ldapmodify to fix things up.

Start by looking at the new value for ipaCert. You need to do two things:

# certutil -L -d /etc/httpd/alias -n ipaCert | grep -i serial

Next you need the base64-encoded value of the cert like before:

# certutil -L -d /etc/httpd/alias -n ipaCert -a

Again you'll need to drop the header/footer and combine this into a single line.

Next see what is already there with:

# ldapsearch -x -h localhost -p 7389 -D 'cn=directory manager' -W -b uid=ipara,ou=People,o=ipaca

You need to replace the serial number in the description attribute with the new one. The serial number is the 2nd number. The format of the description line is:

2;<serial number>;<issuer subject>;<subject>

The change is going to look something like:

# ldapmodify -x -h localhost -p 7389 -D 'cn=directory manager' -w password
dn: uid=ipara,ou=people,o=ipaca
changetype: modify
add: usercertificate
usercertificate:: MII...PNQ=
-
replace: description
description: 2;16;CN=Certificate Authority,O=EXAMPLE.COM;CN=IPA RA,O=EXAMPLE.COM
<extra blank line to finish> 
^D to exit

Now restart the Apache service

# /sbin/service httpd restart

Next we need to renew the two 389-ds and the Apache server certificates.

# ipa-getcert list

For each of the three Request IDs run something like this:

# ipa-getcert resubmit -i <ID>

Restart the world:

# /sbin/service ipa restart

Return to the present time.

# /sbin/service ntpd start
# date (confirm it is now)

To make sure that communication with the CA is working run:

# ipa cert-show 1

Notes

I tested this on a RHEL 6.4 system that I installed ipa-server-2.2.0 and krb5-server-1.9. I did this by:

# date 111110262011
# ipa-server-install -N ...

I confirmed that things were working, then I brought time to today:

# rdate -s <internal NTP server>

So I basically simulated an installation 2 years in the past and see today that my certificates are expired. Then I did the renewal procedure. I did the install without an NTP server because otherwise it would have reset the current time to today during the install, and I wanted to be in the past.