Recently I was developing a AWS Lambda for PowerShell function to read a table from a Microsoft SQL on RDS Instance within a VPC. Using the .NET Core SQL client I need to provide credentials to access the database. For the password it should be stored encrypted at rest, never in plain text, and when passed to the function should be done so as a secure string. We can configure the function to use KMS for encryption at rest. This presents us with two challenges. How do I encrypt a AWS Lambda environment variable and how will my AWS Lambda for PowerShell function securely get the decrypted value in memory as a secure string when the Lambda function is invoked.