Handling Expiring Encryption Keys

Ed Leighton-Dick explains how safely to replace a SQL Server certificate which is about to expire:

So, now that we know what we need to rotate, how do we do it?

First, obtain a new certificate. SQL Server has the capability to generate its own certificates. For many purposes, that’s enough. However, if your company has to comply with auditing or regulatory requirements, you may need to obtain the new certificate from an outside source. Often, this is a third-party certificate authority. Some companies use a system called Encryption Key Management (EKM, also known as a Hardware Security Module, or HSA, after the device used to store the master key). (Obtaining an external certificate is a subject for an upcoming post.)

However you obtained the certificate, install it. Make sure to back it up securely, including the private key.

Next, add the new certificate to the symmetric key. The ALTER CERTIFICATE command has a clause that does just that – ADD ENCRYPTION BY.

Finally, remove the old certificate from the symmetric key. You’ll again use ALTER CERTIFICATE, but this time with the DROP ENCRYPTION BY clause.

Click through for instructions, including scripts.  Ed also explains how to update the certificate used with Transparent Data Encryption.

Related Posts

Active Directory Integration On Ubuntu

Drew Furgiuele shows how to configure SQL Server on Linux to use Windows authentication: In the following post, we’ll walk through joining a Linux SQL Server on Unbuntu to an Active Directory domain, and here’s the steps we’re going to take: Installing the required software and services to enable a Linux host to talk to […]

Read More

Homoglyphs And SQL Injection

Bert Wagner gives us one more reason why blacklists are bad: Homoglpyhs can exist within a character set (like the Latin character set examples above) or they can exist between character sets. For example, you may have the unicode apostrophe ʼ, which is a homoglyph to the Latin single quote character '. How does SQL Server handle unicode […]

Read More

Categories