Method run

src/core/operations/FlaskSessionSign.mjs:53–85

* @param {string} input * @param {Object[]} args * @returns {string}

(input, args)

     * @returns {string}
     */
    run(input, args) {
        if (!args[0].string) {
            throw new OperationError("Secret key required");
        }
        const key = Utils.convertToByteString(args[0].string, args[0].option);
        const salt = Utils.convertToByteString(args[1].string || "cookie-session", args[1].option);
        const algorithm = args[2] || "sha1";

        const payloadB64 = toBase64(Utils.strToByteArray(JSON.stringify(input)));
        const payload = payloadB64.replace(/\+/g, "-").replace(/\//g, "_").replace(/=/g, "");

        const derivedKey = CryptoApi.getHmac(key, CryptoApi.getHasher(algorithm));
        derivedKey.update(salt);

        const currentTimeStamp = Math.ceil(Date.now() / 1000);
        const buffer = new ArrayBuffer(4);
        const view = new DataView(buffer);
        view.setInt32(0, currentTimeStamp, false);
        const bytes = new Uint8Array(buffer);
        let binary = "";
        bytes.forEach(b => binary += String.fromCharCode(b));
        const timeB64 = toBase64(Utils.strToByteArray(binary));
        const time = timeB64.replace(/\+/g, "-").replace(/\//g, "_").replace(/=/g, "");

        const data = Utils.convertToByteString(payload + "." + time, "utf8");
        const sign = CryptoApi.getHmac(derivedKey.finalize(), CryptoApi.getHasher(algorithm));
        sign.update(data);

        const signB64 = toBase64(sign.finalize());
        const sign64 = signB64.replace(/\+/g, "-").replace(/\//g, "_").replace(/=/g, "");

        return payload + "." + time + "." + sign64;
    }
}