"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.GSASRPAuthenticator = void 0;
const js_srp_1 = require("@foxt/js-srp");
const crypto = require("crypto");
let srp = new js_srp_1.Srp(js_srp_1.Mode.GSA, js_srp_1.Hash.SHA256, 2048);
const stringToU8Array = (str) => new TextEncoder().encode(str);
const base64ToU8Array = (str) => Uint8Array.from(Buffer.from(str, "base64"));
class GSASRPAuthenticator {
    constructor(username) {
        this.username = username;
        this.srpClient = undefined;
    }
    async derivePassword(protocol, password, salt, iterations) {
        let passHash = new Uint8Array(await js_srp_1.util.hash(srp.h, stringToU8Array(password)));
        if (protocol == "s2k_fo") {
            passHash = stringToU8Array(js_srp_1.util.toHex(passHash));
        }
        let imported = await crypto.subtle.importKey("raw", passHash, { name: "PBKDF2" }, false, ["deriveBits"]);
        let derived = await crypto.subtle.deriveBits({
            name: "PBKDF2",
            hash: { name: "SHA-256" },
            iterations,
            salt,
        }, imported, 256);
        return new Uint8Array(derived);
    }
    async getInit() {
        if (this.srpClient)
            throw new Error("Already initialized");
        this.srpClient = await srp.newClient(stringToU8Array(this.username), new Uint8Array());
        let a = Buffer.from(js_srp_1.util.bytesFromBigint(this.srpClient.A)).toString("base64");
        return {
            a,
            protocols: ["s2k", "s2k_fo"],
            accountName: this.username,
        };
    }
    async getComplete(password, serverData) {
        if (!this.srpClient)
            throw new Error("Not initialized");
        if (serverData.protocol != "s2k" && serverData.protocol != "s2k_fo")
            throw new Error("Unsupported protocol " + serverData.protocol);
        let salt = base64ToU8Array(serverData.salt);
        let serverPub = base64ToU8Array(serverData.b);
        let iterations = serverData.iteration;
        let derived = await this.derivePassword(serverData.protocol, password, salt, iterations);
        this.srpClient.p = derived;
        await this.srpClient.generate(salt, serverPub);
        let m1 = Buffer.from(this.srpClient._M).toString("base64");
        let M2 = await this.srpClient.generateM2();
        let m2 = Buffer.from(M2).toString("base64");
        return {
            accountName: this.username,
            m1,
            m2,
            c: serverData.c,
        };
    }
}
exports.GSASRPAuthenticator = GSASRPAuthenticator;
