* username for example:
 * <tt>
 * String username = f.getPrincipal().getName();
 * </tt>
 * The <tt>Principal</tt> object returned will never be <tt>null</tt>
 * however the username can be <tt>null</tt> indication anonymous
 * credentials were used (e.g. some IPC$ services).
 */

    public Principal getPrincipal() {
        return auth;
    }

/**

	// Sample bucket policy.
	bucketPolicyBuf := `{"Version":"2012-10-17","Statement":[{"Action":["s3:GetBucketLocation","s3:ListBucket"],"Effect":"Allow","Principal":{"AWS":["*"]},"Resource":["arn:aws:s3:::%s"]},{"Action":["s3:GetObject"],"Effect":"Allow","Principal":{"AWS":["*"]},"Resource":["arn:aws:s3:::%s/this*"]}]}`

	// generate a random bucket Name.
	bucketName := getRandomBucketName()

                        ]
                       }
                      }
                     ]
                    }
                   }
                  ],
                  "principals": [
                   {
                    "and_ids": {
                     "ids": [
                      {
                       "or_ids": {
                        "ids": [