Which additional step should the solutions architect take to troubleshoot this issue?
Ensure that blocking all public access has not been enabled in the S3 bucket.
Verify that the IAM role has permission to decrypt the referenced KMS key.
Verify that the IAM role has the correct trust relationship configured.
Check that local firewall rules are not preventing access to the S3 endpoint.
Explanations:
Enabling “Block all public access” does not impact access from VPC endpoints, as they are intended for private access. Therefore, this setting is not relevant for the developer’s access issue.
If the developer’s IAM role does not have permission to use the KMS key to decrypt the object, it will result in an Access Denied error when trying to access the encrypted S3 object. Verifying the KMS key permissions is crucial.
The trust relationship defines which entities can assume the IAM role. If the role is already confirmed to be assumed correctly, this step is unnecessary for troubleshooting the access issue.
Local firewall rules typically do not affect access to AWS services when using VPC endpoints. If other users can access the bucket without issue, it’s likely not a local firewall problem.
I outline that the answer is:
Verify that the IAM role has permission to decrypt the referenced KMS key.