RobK

var crypto = require("crypto");
/**
 * Get the signature/digest of a supplied input string
 * @param data [Required] The String to encode
 * @param awsSecretKey [Required] Secret key shared with Amazon
 * @param algorithm [Optional] Encryption algorithm, defaults to sha256
 * @param encoding [Optional] The output encoding. Default to base64
 * @returns Str with encoded digest of the input string
 */
function generateHmac (data, awsSecretKey, algorithm, encoding) {