Manipulate FritzBox 6490 (and maybe other) hosts lists.

firtzBoxLibDataLua.js

//manipulate FritzBox Hosts list using data.lua!
'use strict';

const axios = require('axios').default;
const crypto = require('crypto');

function buildUrl(host, path) {
    return 'http://' + host + path;
}

class FirtzBoxLibDataLua {
    /**
     * Constructor
     * @param {Object} options
     * @param {string} options.username
     * @param {string} options.password
     * @param {string} [options.host] defaults to 'fritz.box'
     * @param {boolean} [options.debug]
     */
    constructor(options) {
        this.username = options.username;
        this.password = options.password;
        this.host = options.host || 'fritz.box';
        this.debug = options.debug || false;
        this.sessionId = '';
    }

    log(...parameters) {
        console.log.apply(console, parameters);
    }

    logDebug(...parameters) {
        if(this.debug) {
            console.log.apply(console, parameters);
        }
    }

    /**
     * Login to fritzbox.
     * @returns {Promise<boolean>}
     */
    async login() {
        let result = await axios.get(buildUrl(this.host, '/login_sid.lua'));
        //this.logDebug('Login first result: ', result);
        const challenge = result.data.match('<Challenge>(.*?)</Challenge>')[1];
        this.logDebug('challenge:', challenge);
        const hash = crypto.createHash('md5');
        hash.update(Buffer.from(challenge + '-' + this.password, 'utf16le'));
        const challengeResponse = challenge + '-' + hash.digest('hex');

        const path = '/login_sid.lua?username=' + this.username + '&response=' + challengeResponse;
        this.logDebug('Calling:', path);
        result = await axios.get(buildUrl(this.host, path));
        //this.logDebug('Login second result: ', result);
        this.sessionId = result.data.match('<SID>(.*?)</SID>')[1];
        if (this.sessionId === '0000000000000000') {
            this.logDebug('Could not login:', result.data);
            throw new Error('could not login: ' + result.data);
        }  else {
            this.logDebug('Login success, sid:', this.sessionId);
            return true;
        }
    }

    /**
     * Get all network devices from fritzBox
     * @returns {Promise<Buffer|any[]|string>}
     */
    async getNetworkDevices() {
        let data = 'xhr=1&sid=' + this.sessionId + '&lang=de&page=netDev&xhrId=all&no_sidrenew=';
        let result = await axios.post(buildUrl(this.host, '/data.lua'), data);

        return result.data.data.active.concat(result.data.data.passive);
    }

    /**
     * update Device data
     * @param {object} oldData device from FritzBox
     * @param {{name: string, ip: string}} newData
     * @returns {Promise<boolean|any|{errorText: any, status: number}>}
     */
    async updateDevice(oldData, newData) {
        /*let data = 'dev_name=' + newData.name || oldData.name +
            '&btn_reset_name=&dev_ip=' + newData.ip || oldData.ipv4 + '&static_dhcp=on&kisi_profile=filtprof1' +
            '&back_to_page=%2Fnet%2Fnet_overview.lua&dev=' + oldData.UID + '&last_action=&validate=btn_save&xhr=1&useajax=1';*/
        //return axios.post(buildUrl(this.host, '/net/edit_device.lua?sid=' + this.sessionId), data);
        let data = 'xhr=1&sid=' + this.sessionId + '&lang=de&no_sidrenew=&';
        if (newData.name) {
            data += 'plc_desc=' + oldData.name + '&dev_name=' + newData.name;
        } else {
            data += 'dev_name=' + oldData.name;
        }
        if (newData.ip) {
            data += '&dev_ip=' + newData.ip;
        } else {
            data += '&dev_ip=' + oldData.ipv4;
        }
        data += '&static_dhcp=on&kisi_profile=';
        data += 'filtprof1&back_to_page=%2Fnet%2Fnet_overview.lua';
        data += '&dev=' + oldData.UID + '&last_action=&btn_save=&oldpage=%2Fnet%2Fedit_device.lua';
        let result = await axios.post(buildUrl(this.host, '/data.lua'), data);
        if (typeof result.data === 'string') {
            return {status: result.status, errorText: result.data.substring(0, result.data.indexOf('<script>')) || result.data};
        } else if (result.data.pid !== 'netDev') {
            return result.data;
        } else {
            return true;
        }
    }

    /**
     * Delete device from FritzBox. This sometimes does not work or needs to repeated. Not sure why
     * (But it does not always work in FB UI either... hm)
     * @param oldData
     * @returns {Promise<boolean|any|{errorText: any, status: number}>}
     */
    async deleteDevice(oldData) {
        let data = 'xhr=1&Verbindung=on&IP-Adresse=on&MAC-Adresse=on&Eigenschaften=on&delete=' + oldData.UID +
            '&deleteable=true&devname=' + oldData.name +
            '&devtype=unknown&sid=' + this.sessionId + '&lang=de&page=netDev';
        await axios.post(buildUrl(this.host, '/data.lua'), data);
        data += '&confirmed=';
        let result = await axios.post(buildUrl(this.host, '/data.lua'), data);
        //this.logDebug('Result:', result.status, 'msg:', result.data);
        if (typeof result.data === 'string') {
            return {status: result.status, errorText: result.data.substring(0, result.data.indexOf('<script>')) || result.data};
        } else if (result.data.pid !== 'netDev') {
            return result.data;
        } else {
            return true;
        }
    }

    /**
     *
     * @param {{name: string, ip: string, mac: string}} newData
     * @returns {Promise<boolean|any|{errorText: any, status: number}>}
     */
    async createDevice(newData) {
        const macParts = newData.mac.split(':');
        const ipParts = newData.ip.split('.');
        let data = 'xhr=1&sid=' + this.sessionId;
        data += '&lang=de&no_sidrenew=&name=' + newData.name;
        for (let i = 0; i < 6; i += 1) {
            data += '&mac' + i + '=' + macParts[i];
        }
        for (let i = 0; i < 4; i += 1) {
            data += '&ip' + i + '=' + ipParts[i];
        }
        data += '&back_to_page=%2Fnet%2Fnet_overview.lua&apply=&oldpage=%2Fnet%2Fnewdevice.lua';
        const result = await axios.post(buildUrl(this.host, '/data.lua'), data);
        if (typeof result.data === 'string') {
            return {status: result.status, errorText: result.data.substring(0, result.data.indexOf('<script>')) || result.data};
        } else if (result.data.pid !== 'netDev') {
            return result.data;
        } else {
            return true;
        }
    }
}

module.exports = FirtzBoxLibDataLua;

Use like this:

const FritzBoxLibDataLua = require('./firtzBoxLibDataLua');

async function main() {
    //login to fritzbox -> gets sessionId.
    const fb = new FritzBoxLibDataLua({ username: 'FritzBox', password: 'YOUR PASSWORD'});
    await fb.login();

    let fbDevices = await fb.getNetworkDevices();
    for (const fbDevice of fbDevices) {
        //do something here, like writing to your own file or comparing with other devices file or so
        //you can update like. Both are optional.
        //const result = await fb.updateDevice(fbDevice, {name: "newName", ip: "192.168.0.244"});
        //you can delete like this:
        //await fb.deleteDevice(fbDevice); //sometimes does not work or needs two tries... not sure why.
    }
    //add new devices:
    await fb.createDevice({mac: "someMac", name: "someName", ip: "someIp"});
}

main().then((r) => {
    console.log('All done:', r);
}, (e) => {
    console.log('Had error:', e);
});