Security in Amazon RDS Custom

A service-linked role is predefined by the service and includes all permissions that the service needs to call other AWS services on your behalf. For RDS Custom, AWSServiceRoleForRDSCustom is a service-linked role that is defined according to the principle of least privilege. RDS Custom uses the permissions in AmazonRDSCustomServiceRolePolicy, which is the policy attached to this role, to perform most provisioning and all off-host management tasks. For more information, see AmazonRDSCustomServiceRolePolicy.

When it performs tasks on the host, RDS Custom automation uses credentials from the service-linked role to run commands using AWS Systems Manager. You can audit the command history through the Systems Manager command history and AWS CloudTrail. Systems Manager connects to your RDS Custom DB instance using your networking setup. For more information, see Step 4: Configure IAM for RDS Custom for Oracle.

When provisioning or deleting resources, RDS Custom sometimes uses temporary credentials derived from the credentials of the calling IAM principal. These IAM credentials are restricted by the IAM policies attached to that principal and expire after the operation is completed. To learn about the permissions required for IAM principals who use RDS Custom, see Step 5: Grant required permissions to your IAM user or role.

An EC2 instance profile is a container for an IAM role that you can use to pass role information to an EC2 instance. An EC2 instance underlies an RDS Custom DB instance. You provide an instance profile when you create an RDS Custom DB instance. RDS Custom uses EC2 instance profile credentials when it performs host-based management tasks such as backups. For more information, see Create your IAM role and instance profile manually.

When RDS Custom creates the EC2 instance that underlies a DB instance, it creates an SSH key pair on your behalf. The key uses the naming prefix do-not-delete-rds-custom-ssh-privatekey-db-. AWS Secrets Manager stores this SSH private key as a secret in your AWS account. Amazon RDS doesn't store, access, or use these credentials. For more information, see Amazon EC2 key pairs and Linux instances.