What is the MOST secure way to pass these credentials to the Lambda function?
Use a CloudFormation parameter to pass the master user credentials at deployment to the OpenSearch Service domain’s MasterUserOptions and the Lambda function’s environment variable. Set the NoEcho attribute to true.
Use a CloudFormation parameter to pass the master user credentials at deployment to the OpenSearch Service domain’s MasterUserOptions and to create a parameter in AWS Systems Manager Parameter Store. Set the NoEcho attribute to true. Create an IAM role that has the ssm GetParameter permission. Assign the role to the Lambda function. Store the parameter name as the Lambda function’s environment variable. Resolve the parameter’s value at runtime
Use a CloudFormation parameter to pass the master user credentials at deployment to the OpenSearch Service domain’s MasterUserOptions and the Lambda function’s environment variable. Encrypt the parameter’s value by using the AWS Key Management Service (AWS KMS) encrypt command.
Use CloudFormation to create an AWS Secrets Manager secret. Use a CloudFormation dynamic reference to retrieve the secret’s value for the OpenSearch Service domain’s MasterUserOptions. Create an IAM role that has the secretsmanager:GetSecretValue permission. Assign the role to the Lambda function. Store the secret’s name as the Lambda function’s environment variable. Resolve the secret’s value at runtime.
Explanations:
While using a CloudFormation parameter with the NoEcho attribute provides some security by hiding the value in the console output, it does not adequately secure the credentials. The credentials would still be exposed in Lambda environment variables, making them potentially accessible to anyone with permissions to view the function configuration. This option lacks a robust method for secure credential management.
This option does provide a level of security by utilizing AWS Systems Manager Parameter Store and the NoEcho attribute to hide the credentials during CloudFormation stack creation. However, it requires passing the master user credentials as a parameter, which still presents a risk if the stack is compromised. Additionally, using SSM Parameter Store with the IAM role approach is more secure but not as optimal as using AWS Secrets Manager.
This option involves encrypting the master user credentials using AWS KMS, which adds a layer of security. However, passing the credentials directly to the Lambda function’s environment variables still exposes them to anyone who can access the Lambda configuration. The method of encryption does not address the underlying security concern of environment variable exposure.
This option is the most secure as it utilizes AWS Secrets Manager to store the master user credentials securely. By using a CloudFormation dynamic reference, the secret is retrieved at runtime without exposing the value in CloudFormation parameters or Lambda environment variables. The IAM role assigned to the Lambda function, with permissions to retrieve the secret, further enhances security by ensuring that only authorized entities can access the sensitive information. This method adheres to best practices for secret management in AWS.
I think the answer is:
Use CloudFormation to create an AWS Secrets Manager secret. Use a CloudFormation dynamic reference to retrieve the secret’s value for the OpenSearch Service domain’s MasterUserOptions. Create an IAM role that has the secretsmanager:GetSecretValue permission. Assign the role to the Lambda function. Store the secret’s name as the Lambda function’s environment variable. Resolve the secret’s value at runtime.
As I see it, the answer is:
Use CloudFormation to create an AWS Secrets Manager secret. Use a CloudFormation dynamic reference to retrieve the secret’s value for the OpenSearch Service domain’s MasterUserOptions. Create an IAM role that has the secretsmanager:GetSecretValue permission. Assign the role to the Lambda function. Store the secret’s name as the Lambda function’s environment variable. Resolve the secret’s value at runtime.