Testing AWS SSM SecureString parameter reads locally with Yulin

Application configuration in AWS Systems Manager Parameter Store often mixes plain values with SecureString ones. A SecureString read comes back encrypted unless the request specifically asks for decryption. Nothing fails at that point, so you just get the base64 encoded ciphertext. Simulated SSM in Yulin encrypts a SecureString value through simulated KMS when it is written, so a local test reads…