Replace Self-Signed FAST Search Certificate with Third Party Certificate

Question

We are trying to replace the Self-Signed FAST Search Certificate with Third Party Certificate in our SP 2010 environment. And are facing issues while enabling the SSL communication between the FAST servers and the corporate servers.
Our FAST search servers are in a different farm than that of the Corporate Servers.
The details of the certificate we received is as follows:
Issued to : FastSearchCert
Issued By: Issuer Name
Valid From: 4/21/2015 to 4/20/2017
We were able to successfully renew the certificate on the FAST Search Server by following the below steps:
1.  Login to the Administrative and the Non-Administrative nodes 
of the FAST server. Go to Windows Service and stop the FAST Search for SharePoint and the FAST Search for SharePoint Monitoring services in both the servers.
Follow the below steps in the Administrative Node followed by the Non-Administrative Node
2. 
Install the certificate in the following paths in the certificate store:
“Certificates(Local Computer)\Personal”
“Certificates(Local Computer)\Trusted Root Certification Authorities”
3. Ensure that the user account configured for the “FAST Search Server 2010 for SharePoint” has access to the private key of the certificate.
4. Go the Administrative node of the FAST farm and follow the below steps:
Go to the certificate store.
Expand the Personal folder and then click the Certificates folder. Double-click the third party signed FAST certificate.
Open the Details tab and then click Thumbprint. Note down this thumbprint.
5. Next, open
Microsoft FAST Search Server 2010 for SharePoint with Administrator
Privileges.
6.
Navigate to the directory, “D:\FASTSearch\installer\scripts” and execute the below command to replace the current certificate with the newly created
third party signed FAST certificate.
.\ReplaceDefaultCertificate.ps1 -thumbprint "certificate thumbprint".
7. The FAST certificate was renewed successfully.
Once the certificate has been renewed successfully in both the nodes, follow the below step:
8. Start the FASTSearch for SharePoint and the FAST Search
for SharePoint Monitoring services in the administrator server.
Next, while enabling the SSL communication between the FAST servers and the other corporate servers, we follow the below steps:
1. 
Copy the new certificate from any of the FAST servers to all the web-front end and application servers in the corporate farm, in order to enable SSL communication between these servers and the FAST farm.
2.   Also, copy the script
‘SecureFASTSearchConnector.ps1’ from the location “%FASTSearchFolder%\installer\scripts” in the FAST servers 
to the web-front end and application servers of the corporate farm.
3.  Follow the below steps on each of the servers in the corporate farm:
Open ‘SharePoint 2010 Management Shell’ with administrator privileges and navigate to the directory in which
SecureFASTSearchConnector.ps1’ script is located.
And then, execute the below command:
 .\SecureFASTSearchConnector.ps1 -certThumbprint "certificate thumbprint" –ssaName “FASTCibtebtSSA” –username “DOMAIN\SP_Farm”
 Where,
-certThumbprint 
- Thumbprint of the certificate
-ssaName – FAST Content SSA
-username – The account configured to run the SharePoint
Search Service
On execution of the above command, we receive an error message stating that the "Connection to the Content Distributor servername.corp.abc.org: 14391 could not be validated...instance of FAST search server backend is running"
Please help us resolve this issue. We have not been able to find the cause of the above error for a long time.
Any help is much appreciated.

Answer 1

Your tip on exporting from eDir to locate a missing private key was very helpful. Here are my steps to renew an expired third party certificate when the private key, generated 30 months ago in my case, could not be located.
In iManager, browse the tree and locate the likely certificate object. The Attributes for the object show Subject Name = webmail.acme.com. Selected the certificate and exported to webmailcert.pfx.
Then, the openssl commands in TID 7004039, "How to convert a SSL PFX to a PEM file", were run against the .pfx file to create cert.pem, key.pem and server.key files.
TID 7015500, "How to determine if private key belongs to public key (certificate)", was followed to determine if the public key (downloaded from third party) and private key (just retrieved from iManager) match - they did - that is, the private key converted from webmailcert.pfx matches the downloaded certificate.
TID 7013103, "How to create a .pem File for SSL certificate Installations", was followed to manually create a server.pem file using openssl.
TID 7010584, "How to setup SSL Certificate for Apache", part labeled "Additional Information" was followed to modify /etc/apache2/vhosts.d/vhost-ssl.conf file. Server.pem file created above copied to /etc/apache2/ssl.crt/ and /etc/ssl/servercerts/ directories as specified in vhost-ssl.conf.
Restarted apache2.
www.digicert.com has an SSL Certificate Checker that can be used to verify the installation is successful.