Extend MS Exchange Server's Certificate life
On the Certification Authority Server open Certification Authority Console (MMC)
Right click on Certificate Templates and click Manage
IN certificate templates console right click on Web Server and click Duplicate template
Select Windows Server 2003 Enterprise
Enable "Allow private key to be exported"
Under security tab Select Enroll for the Authenticated users
Back to the Certificate Authority Console, Right click on Certificate Templates and click New -> Certificate template to issue and add the certificate template you created to the list.
Web Server V2 is on top
Let's check it on Certserv IIS
Certificate is generated for 5 years. The reason why the certificate is generated for 5 years is because the Certification Authority server's Certificate is limited to 5 years.
So the CA certificate must be set to longer then the client's requested Certificate limit.
Certification Authority Issuing Certificate validity period extending
To change the Validity Period for the Root CA you can configure a CAPolicy.inf. To create a CAPolicy.inf file that changes the lifietime of the certificate to 30 years, you would type the following into a text file, and save it with the name CAPolicy.inf in the C:\Windows directory,:
Signature= "$Windows NT$"
After this you will need to renew the CA certificate from the CA console : right click on your certification authority and choose All Tasks -> then choose -> Renew CA Certificate
When you click on Renew CA certificate you will get the following prompt asking you to stop the CA to renew its Certificate, Click Yes
Once you click on Yes the service will stop and you will get this window telling you if you would like to generate new public and private key it's up to you to use a new or not but if you choose Yes the clients using the old Certificate might be provoked and you might need to install the new CA Certificate on all clients using GPO.
After clicking OK you will see that you were able to generate the new CA Certificate and then you can issue clients certificates
Note: I created another template with 30 years expiration date this time after I created the CA policy for 30 years too.
Now In order to allow the CA to issue certificates that has longer than the default age (2 years) you must run the following command line on the CMD on the CA server.
And here we go, after requesting the certificate from the server I got 30 years valid certificate.