Configuring DNSSEC signing in Amazon Route 53 - Amazon Route 53

Configuring DNSSEC signing in Amazon Route 53

Domain Name System Security Extensions (DNSSEC) signing lets DNS resolvers validate that a DNS response came from Amazon Route 53 and has not been tampered with. When you use DNSSEC signing, every response for a hosted zone is signed using public key cryptography.

In this chapter, we explain how to enable DNSSEC signing for Route 53, how to work with key signing keys (KSKs), and how to troubleshoot issues. You can work with DNSSEC signing in the AWS Management Console or programmatically with the API. For more information about using the CLI to set up DNSSEC signing, see Using the AWS CLI to enable DNSSEC signing. For more information about using the CLI or SDKs to work with Route 53, see Setting up Amazon Route 53.

Enabling DNSSEC signing has two steps:

  • Step 1: Enable DNSSEC signing for Route 53, and request that Route 53 create a key signing key (KSK) based on a customer managed customer master key (CMK) in AWS Key Management Service (AWS KMS).

  • Step 2: Create a chain of trust for the hosted zone by adding a Delegation Signer (DS) record to the parent zone, so DNS responses can be authenticated with trusted cryptographic signatures.

Instructions for completing each of these steps are included in this chapter, in the section Enabling DNSSEC signing and establishing a chain of trust.

Before you enable DNSSEC signing, note the following:

  • To help prevent a zone outage and avoid problems with your domain becoming unavailable, you must quickly address and resolve DNSSEC errors. We strongly recommend that you set up a CloudWatch alarm that alerts you whenever a DNSSECInternalFailure or DNSSECKeySigningKeysNeedingAction error is detected. For more information, see Monitoring hosted zones using Amazon CloudWatch.

  • There are two kinds of keys in DNSSEC: a key-signing key (KSK) and a zone-signing key (ZSK). In Route 53 DNSSEC signing, each KSK is based on an asymmetric CMK in AWS KMS that you own. You are responsible for KSK management, which includes rotating it if needed. ZSK management is performed by Route 53.

  • When you enable DNSSEC signing for a hosted zone, Route 53 limits the TTL to one week. If you set a TTL of more than one week for records in the hosted zone, you don't get an error. However, Route 53 enforces a TTL of one week for the records. Records that have a TTL of less than one week and records in other hosted zones that do not have DNSSEC signing enabled are not affected.

  • When you use DNSSEC signing, multi-vendor configurations are not supported.

  • It can be helpful to set up IAM permissions to allow another user, besides the zone owner, to add or remove records in the zone. For example, a zone owner can add a KSK and enable signing, and might also be responsible for key rotation. However, someone else might be responsible for working with other records for the hosted zone. For an example IAM policy, see Example permissions for a domain record owner.