AWS KMS-User is not authorized to perform: kms:Decrypt
Are you facing the frustrating AWS KMS error message, “AWS KMS-User is not authorized to perform: kms:Decrypt on the resource associated with this ciphertext”? This error often arises due to issues with IAM user access configurations. Here’s a step-by-step guide to troubleshoot and resolve this issue effectively:
- Check Regional Discrepancies: Ensure that your KMS keys are located in the same AWS region as the IAM user or role making the request. Cross-regional access can lead to authorization errors.
- Review Resource-Based Policies: Examine resource-based policies applied to your KMS keys. If no policies exist or if they do not grant access to IAM users or roles, consider creating or modifying policies to allow the necessary access.
- Address Denial Policies: If resource-based policies explicitly deny access to IAM users or roles, adjust these policies accordingly to grant the required permissions.
- Evaluate VPC Endpoint Policies: Verify if there are any policies applied at the VPC endpoints level that restrict access to KMS keys from outside the VPC. Adjust these policies if necessary to enable the required access.
- Check Security Group Settings: Assess the security group configurations to ensure that access to KMS endpoints from outside the VPC is allowed. In cases where access is restricted to specific EC2 instances within the VPC, adjust the security group settings accordingly.
By following these troubleshooting steps, you can identify and resolve the underlying issues causing the AWS KMS error related to IAM user access. Implementing these solutions will help ensure seamless access to KMS keys and enhance the security of your AWS environment.