GenerateSignature.java

/**
 * Este metodo es el que genera la firma 
 * url es el url que estamos llamando String url = containerReqCtxt.getUriInfo().getAbsolutePath().toString();
 * params es el mapa con los query params y body params (ver metodo extractInputParams)
 * authkey es la llave secreta
 */
public static String generateSignature(String url,
			Map<String, Object> params, String authKey)
			throws NoSuchAlgorithmException, InvalidKeyException,
			IllegalStateException, UnsupportedEncodingException {
		// sort the params alphabetically, and append the key and value of each
		// to the url
		logger.info("url: {}", url);
		logger.info("params: {}", params);
		logger.info("authKey: {}", authKey);
		StringBuffer data = new StringBuffer(url);
		if (params != null) {
			List<String> sortedKeys = new ArrayList<String>(params.keySet());
			Collections.sort(sortedKeys);
			for (String key : sortedKeys) {
				data.append(key);
				String value = "";
				if (params.get(key) != null) {
					Object objectValue = params.get(key);
					if (objectValue instanceof List || objectValue instanceof Map) {
						value = "[]";
					} else {
						value = String.valueOf(objectValue);
					}
				}
				data.append(value);
			}
		}
		logger.info("data: {}", data);
		SecretKeySpec signkey = new SecretKeySpec(authKey.getBytes(), HMACSHA1_ALGORITHM);
		Mac mac = Mac.getInstance(HMACSHA1_ALGORITHM);
		mac.init(signkey);
		
		byte[] macbytes = mac.doFinal(data.toString().getBytes("UTF-8"));
		String result = new String(Base64.encodeBase64(macbytes));
		logger.debug("Generated Signature: {}", result);
		return result;
	}
	
/**
 * Extracts all the call parameters.
 * 
 * @param containerReqCtxt
 *            REST Container Request Context.
 * @return Map with all the call parameters.
 * @throws ProcessingException
 * @throws InternalServerErrorException
 */
private Map<String, Object> extractInputParams(ContainerRequestContext containerReqCtxt)
        throws ProcessingException, InternalServerErrorException {
    
    Map<String, Object> params = new HashMap<String, Object>();
    MultivaluedMap<String, String> queryParams = containerReqCtxt.getUriInfo().getQueryParameters();
    for (Entry<String, List<String>> entry : queryParams.entrySet()) {
        params.put(entry.getKey(), entry.getValue().get(0));
    }
    // Get Body Parameters
    if (containerReqCtxt.hasEntity()) {
        if ((containerReqCtxt instanceof ContainerRequest)) {
            ContainerRequest containerReq = (ContainerRequest) containerReqCtxt;
            containerReq.bufferEntity();
            @SuppressWarnings("unchecked")
            Map<String, String> bodyParams = containerReq.readEntity(HashMap.class);
            params.putAll(bodyParams);
        } else {
            logger.error("Invalid instance Container request context [{}]", containerReqCtxt.getClass().getName());
            throw new InternalServerErrorException();
        }
    }
    return params;
}