Enable Encrypted Connections to the Database Engine
This topic describes how to enable encrypted connections for an instance of the SQL Server Database Engine by specifying a certificate for the Database Engine using SQL Server Configuration Manager. The server computer must have a certificate provisioned, and the client machine must be set up to trust the certificate's root authority. Provisioning is the process of installing a certificate by importing it into Windows.
The certificate must be issued for Server Authentication. The name of the certificate must be the fully qualified domain name (FQDN) of the computer.
Certificates are stored locally for the users on the computer. To install a certificate for use by SQL Server, you must be running SQL Server Configuration Manager with an account that has local administrator privileges.
The client must be able to verify the ownership of the certificate used by the server. If the client has the public key certificate of the certification authority that signed the server certificate, no further configuration is necessary. Microsoft Windows includes the public key certificates of many certification authorities. If the server certificate was signed by a public or private certification authority for which the client does not have the public key certificate, you must install the public key certificate of the certification authority that signed the server certificate.
To use encryption with a failover cluster, you must install the server certificate with the fully qualified DNS name of the virtual server on all nodes in the failover cluster. For example, if you have a two-node cluster, with nodes named test1.<your company>.com and test2.<your company>.com, and you have a virtual server named virtsql, you need to install a certificate for virtsql.<your company>.com on both nodes. You can set the value of the ForceEncryption option to Yes.
When creating encrypted connections for an Azure Search indexer to SQL Server on an Azure VM, see Configure a connection from an Azure Search indexer to SQL Server on an Azure VM.
For SQL Server to load an SSL certificate, the certificate must meet the following conditions:
- The certificate must be in either the local computer certificate store or the current user certificate store.
- The SQL Server Service Account must have the necessary permission to access the SSL certificate.
- The current system time must be after the Valid from property of the certificate and before the Valid to property of the certificate.
- The certificate must be meant for server authentication. This requires the Enhanced Key Usage property of the certificate to specify Server Authentication (188.8.131.52.184.108.40.206.1).
- The certificate must be created by using the KeySpec option of AT_KEYEXCHANGE. Usually, the certificate's key usage property (KEY_USAGE) will also include key encipherment (CERT_KEY_ENCIPHERMENT_KEY_USAGE).
- The Subject property of the certificate must indicate that the common name (CN) is the same as the host name or fully qualified domain name (FQDN) of the server computer. If SQL Server is running on a failover cluster, the common name must match the host name or FQDN of the virtual server and the certificates must be provisioned on all nodes in the failover cluster.
- SQL Server 2008 R2 and the SQL Server 2008 R2 Native Client support wildcard certificates. Other clients might not support wildcard certificates. For more information, see the client documentation and KB258858.
To provision (install) a certificate on the server
Refer to Certificate Management (SQL Server Configuration Manager) to add a certificate on a single server.
On the Start menu, click Run, and in the Open box, type MMC and click OK.
In the MMC console, on the File menu, click Add/Remove Snap-in.
In the Add/Remove Snap-in dialog box, click Add.
In the Add Standalone Snap-in dialog box, click Certificates, click Add.
In the Certificates snap-in dialog box, click Computer account, and then click Finish.
In the Add Standalone Snap-in dialog box, click Close.
In the Add/Remove Snap-in dialog box, click OK.
In the Certificates snap-in, expand Certificates, expand Personal, and then right-click Certificates, point to All Tasks, and then click Import.
Right-click the imported certificate, point to All Tasks, and then click Manage Private Keys. In the Security dialog box, add read permission for the user account used by the SQL Server service account.
Complete the Certificate Import Wizard, to add a certificate to the computer, and close the MMC console. For more information about adding a certificate to a computer, see your Windows documentation.
To provision (install) a certificate across multiple servers
Refer to Certificate Management (SQL Server Configuration Manager) to add a certificate across multiple servers.
To export the server certificate
From the Certificates snap-in, locate the certificate in the Certificates / Personal folder, right-click the Certificate, point to All Tasks, and then click Export.
Complete the Certificate Export Wizard, storing the certificate file in a convenient location.
To configure the server to force encrypted connections
In SQL Server Configuration Manager, expand SQL Server Network Configuration, right-click Protocols for <server instance>, and then selectProperties.
In the Protocols for <instance name> Properties dialog box, on the Certificate tab, select the desired certificate from the drop-down for the Certificate box, and then click OK.
On the Flags tab, in the ForceEncryption box, select Yes, and then click OK to close the dialog box.
Restart the SQL Server service.
To ensure secure connectivity between client and server, configure the client to request encrypted connections. More details are explained later in this article.
Beginning with SQL Server 2008, SQL Server and the SQL Server Native Client support wildcard certificates. Other clients might not support wildcard certificates. For more information, see the client documentation. Wildcard certificate cannot be selected by using the SQL Server Configuration Manager. To use a wildcard certificate, you must edit the
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL12.MSSQLSERVER\MSSQLServer\SuperSocketNetLib registry key, and enter the thumbprint of the certificate, without spaces, to the Certificate value.
Incorrectly editing the registry can severely damage your system. Before making changes to the registry, we recommend that you back up any valued data on the computer.
To configure the client to request encrypted connections
Copy either the original certificate or the exported certificate file to the client computer.
On the client computer, use the Certificates snap-in to install either the root certificate or the exported certificate file.
In the console pane, right-click SQL Server Native Client Configuration, and then click Properties.
On the Flags page, in the Force protocol encryption box, click Yes.
To encrypt a connection from SQL Server Management Studio
On the Object Explorer toolbar, click Connect, and then click Database Engine.
In the Connect to Server dialog box, complete the connection information, and then click Options.
On the Connection Properties tab, click Encrypt connection.
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