protected String getUserPrivateKey() {
		BufferedReader br = null;
		StringBuffer sb = null;

		try {
			if (hasUserKeyFile()) {
				File f = getUserKeyFile();
				br = new BufferedReader(new InputStreamReader(
						new FileInputStream(f)));
				sb = new StringBuffer();
				while (br.ready()) {
					sb.append(br.readLine());
					sb.append("\n");
				}

				return sb.toString();
			} else {
				return null;
			}
		} catch (Exception e) {
			throw new Error(e);
		} finally {
			if (br != null) {
				try {
					br.close();
				} catch (Exception e) {
				}
			}
		}
	}