latchheader.js

    var authorizationHeader = config.AUTHORIZATION_METHOD + config.AUTHORIZATION_HEADER_FIELD_SEPARATOR + 
                           config.appId + config.AUTHORIZATION_HEADER_FIELD_SEPARATOR + signData(stringToSign);

    var headers = {};
    headers[config.AUTHORIZATION_HEADER_NAME] = authorizationHeader;
    headers[config.DATE_HEADER_NAME] = utc;