Force encryption on SQL Server not working?

Question

Hello Everyone,
I'm running SQL Server 2008 64-bit. I've installed a self-signed cert on the box and set  "Force Encryption"  and restarted SQL server. 
I setup a client machine to trust the authority of the cert installed on the server. When I connect to that SQL server from SSMS from a client machine and select the "encrypt connection" option in the client Connection properties, SSMS correctly complains
that the cert on the server does not match the computer name I asked to log into . This is because, although the cert is trusted, the dns name dos not match the CN in the cert <- Perfect, exactly what I am expecting.
When I connect to the same SQL server from the same client but  UNCHECK "encrypt connection" on the client, I'm able to login. Considering I've checked the "Force Encryption" on the server, the server should have rejected the connection. Why not?
Ameer Deen

Answer 1

Hi all,
We are implementing a Merge Synchronization solution which involves three SQL Servers located on three Azure locations worldwide and one on-premises location. We need to secure communications between all servers. We are evaluating the encryption of all server
communications through SSL:
http://technet.microsoft.com/en-us/library/ms191192.aspx
When we configure one server (let’s call it server A) to accept only encrypted connections (with Force Encryption=Yes) we still can connect from other server (let’s call it server B) that do not have the certificate installed. We would expect the server
B to fail in the attempt of connect as server A should only accept encrypted communications and those should need the certificated to encrypt/decrypt everything (commands and data).
We have also review the following forum post that is very similar to this one:
http://social.msdn.microsoft.com/Forums/sqlserver/en-US/bde679d9-ff83-4fa7-b402-42e336a97106/force-encryption-on-sql-server-not-working
In all cases the Microsoft answer is:
“When the
Force Encryption option for the Database Engine is set to YES, all communications between client and server is encrypted no matter whether the “Encrypt
connection” option (such as from SSMS) is checked or not. You can check it using the following DMV statement”
When we run the provided DMV statement to check if encryption is enabled:
-- To check whether connections are encrypted between server and clients
SELECT encrypt_option
FROM sys.dm_exec_connections
We get “TRUE”. So theoretically encryption is enabled.
Then:
Why can we run SQL statements against server A from server B (with SSMS) without any certificate?
Are we wrong when we expect server A to refuse any client that do not have the right certificate?
How can server B, without any certificate, decrypt the data encrypted by server A?
Our intention is to encrypt all server in the same way so all of them will accept only encrypted communications. We are assuming that the Merge Agent will be able to communicate with the Publisher and the Subscriber through this encrypted environment. May
anyone please confirm ti?
Thanks for your help.
Best Regards
Benjamin Moles