Amazon OpenSearch Service is a managed service to host OpenSearch instances. It replaces Elasticsearch Service, which has been deprecated.

To harden domain (cluster) data in case of unauthorized access, OpenSearch provides data-at-rest encryption if the engine is OpenSearch (any version), or Elasticsearch with a version of 5.1 or above. Enabling encryption at rest will help protect:

Thus, adversaries cannot access the data if they gain physical access to the storage medium.

Ask Yourself Whether

There is a risk if you answered yes to any of those questions.

Recommended Secure Coding Practices

It is recommended to encrypt OpenSearch domains that contain sensitive information.

OpenSearch handles encryption and decryption transparently, so no further modifications to the application are necessary.

Sensitive Code Example

For aws_cdk.aws_opensearchservice.Domain:

from aws_cdk.aws_opensearchservice import Domain, EngineVersion

class DomainStack(Stack):
    def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
        super().__init__(scope, construct_id, **kwargs)

        Domain(self, "Sensitive",
            version=EngineVersion.OPENSEARCH_1_3
        ) # Sensitive, encryption is disabled by default

For aws_cdk.aws_opensearchservice.CfnDomain:

from aws_cdk.aws_opensearchservice import CfnDomain

class CfnDomainStack(Stack):
    def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
        super().__init__(scope, construct_id, **kwargs)

        CfnDomain(self, "Sensitive") # Sensitive, encryption is disabled by default

Compliant Solution

For aws_cdk.aws_opensearchservice.Domain:

from aws_cdk.aws_opensearchservice import Domain, EncryptionAtRestOptions, EngineVersion

class DomainStack(Stack):
    def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
        super().__init__(scope, construct_id, **kwargs)

        Domain(self, "Compliant",
            version=EngineVersion.OPENSEARCH_1_3,
            encryption_at_rest=EncryptionAtRestOptions(
                enabled=True
            )
        )

For aws_cdk.aws_opensearchservice.CfnDomain:

from aws_cdk.aws_opensearchservice import CfnDomain

class CfnDomainStack(Stack):
    def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
        super().__init__(scope, construct_id, **kwargs)

        CfnDomain(self, "Compliant",
            encryption_at_rest_options=CfnDomain.EncryptionAtRestOptionsProperty(
                enabled=True
            )
        )

See