Get an object's KMS key name

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name) {
  StatusOr<gcs::ObjectMetadata> metadata =
      client.GetObjectMetadata(bucket_name, object_name);
  if (!metadata) throw std::move(metadata).status();

  std::cout << "KMS key on object " << metadata->name() << " in bucket "
            << metadata->bucket() << ": " << metadata->kms_key_name() << "\n";
}

use Google\Cloud\Storage\StorageClient;

/**
 * Retrieve the KMS key of an object.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $objectName The name of your object in the bucket.
 *        (e.g. 'my-object')
 */
function object_get_kms_key(string $bucketName, string $objectName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $info = $object->info();

    printf(
        'The KMS key of the object is %s' . PHP_EOL,
        $info['kmsKeyName'],
    );
}

from google.cloud import storage


def object_get_kms_key(bucket_name, blob_name):
    """Retrieve the KMS key of a blob"""
    # bucket_name = "your-bucket-name"
    # blob_name = "your-object-name"

    storage_client = storage.Client()

    bucket = storage_client.bucket(bucket_name)
    blob = bucket.get_blob(blob_name)

    kms_key = blob.kms_key_name

    print(f"The KMS key of a blob is {blob.kms_key_name}")
    return kms_key