Amazon S3修改Bucket ACL

Question

我想使用API​​ for PHP 2为日志传送组启用存储桶权限

    $result = $client->putBucketAcl(array(
        'Bucket' => $bucket . '-log',
        'AccessControlList' => array(
            'Grant' => array(
                'Grantee' => array(
                    'Type' => 'Group',
                    'URI' => 'http://acs.amazonaws.com/groups/s3/LogDelivery',
                ),
                'Permission' => 'WRITE',
            ),
            'Grant' => array(
                'Grantee' => array(
                    'Type' => 'Group',
                    'URI' => 'http://acs.amazonaws.com/groups/s3/LogDelivery',
                ),
                'Permission' => 'READ_ACP',
            ),
        ),
    ));

以下代码的结构写在http://docs.aws.amazon.com/AmazonS3/2006-03-01/dev/LoggingHowTo.html。

执行此代码失败，但出现异常：

 **Aws\S3\Exception\MissingSecurityHeaderException**

 Your request was missing a required header

我找不到如何解决此异常并在存储桶上设置ACL。我错过了一些重要的事情吗？