TokenUtils

TokenUtils

@Component
public class TokenUtils {

    private static final Logger LOGGER = LoggerFactory.getLogger(TokenUtils.class);
    private static final String UTF = "UTF-8";

    @Autowired
    private PasswordEncoder passwordEncoder;

    public static final String MAGIC_KEY = "obfuscate";

    public static final String TOKEN_HEADER = "X-Auth-Token";
    public static final String REQUEST_PARAM = "token";
    public static final String TOKEN_COOKIE = "etracker_token";


    public String createToken(UserDetails userDetails) throws UnsupportedEncodingException {

		/* Expires in one hour */
        String expires = Long.valueOf(System.currentTimeMillis() + 1000L * 60 * 60).toString();

        StringBuilder tokenBuilder = new StringBuilder();
        tokenBuilder.append(userDetails.getUsername());
        tokenBuilder.append(":");
        tokenBuilder.append(expires);
        tokenBuilder.append(":");
        tokenBuilder.append(this.computeSignature(userDetails, expires));

        return tokenBuilder.toString();
    }


    public String computeSignature(UserDetails userDetails, String expires) throws UnsupportedEncodingException {


        StringBuilder signatureBuilder = new StringBuilder();
        signatureBuilder.append(userDetails.getUsername());
        signatureBuilder.append(":");
        signatureBuilder.append(expires);
        signatureBuilder.append(":");
        signatureBuilder.append(userDetails.getPassword());
        signatureBuilder.append(":");
        signatureBuilder.append(TokenUtils.MAGIC_KEY);

        MessageDigest messageDigest = null;
        try {
            messageDigest = MessageDigest.getInstance("MD5");
        } catch (NoSuchAlgorithmException e) {
            LOGGER.error("cannot verify security token",e);
        }
        messageDigest.update(signatureBuilder.toString().getBytes(UTF));
        String encryptedString = new String(Hex.encode(messageDigest.digest()));

        return encryptedString;
    }


    public String getUserNameFromToken(String authToken) {

        if (null == authToken) {
            return null;
        }

        String[] parts = authToken.split(":");
        return parts[0];
    }


    public boolean validateToken(String authToken, UserDetails userDetails) throws UnsupportedEncodingException {

        String[] parts = authToken.split(":");
        String signature = parts[2];
        String expires = parts[1];

        if (Long.valueOf(expires) < System.currentTimeMillis()) {
            return false;
        }
        return signature.equals(this.computeSignature(userDetails, expires));
    }
}