B 站直播弹幕的 WebSocket 获取尝试与抽奖程序实现

{
    "code": 0,
    "msg": "ok",
    "message": "ok",
    "data": {
        "room_id": long_id,
        "short_id": 0,
        "uid": user_id,
        "need_p2p": 0,
        "is_hidden": false,
        "is_locked": false,
        "is_portrait": false,
        "live_status": 1,
        "hidden_till": 0,
        "lock_till": 0,
        "encrypted": false,
        "pwd_verified": false,
        "live_time": 1735877407,
        "room_shield": 0,
        "is_sp": 0,
        "special_type": 0
    }
}

{
    "code": 0,
    "message": "0",
    "ttl": 1,
    "data": {
        "group": "live",
        "business_id": 0,
        "refresh_row_factor": 0.125,
        "refresh_rate": 100,
        "max_delay": 5000,
        "token": "token",
        "host_list": [
            {
                "host": "zj-cn-live-comet.chat.bilibili.com",
                "port": 2243,
                "wss_port": 2245,
                "ws_port": 2244
            },
            ...
        ]
    }
}

// 生成心跳包
function generateHeartbeat(): Buffer {
    const headerLength = 16;
    const protocol = 1;
    const type = 2;
    const sequence = 2;
    // 好小众的内容格式（
    const body = '[Object object]';

    const bodyBuffer = Buffer.from(body);
    const headerBuffer = Buffer.alloc(headerLength);
    headerBuffer.writeUInt32BE(headerLength + bodyBuffer.length, 0);
    headerBuffer.writeUInt16BE(headerLength, 4);
    headerBuffer.writeUInt16BE(protocol, 6);
    headerBuffer.writeUInt32BE(type, 8);
    headerBuffer.writeUInt32BE(sequence, 12);

    return Buffer.concat([headerBuffer, bodyBuffer]);
}

win2.on('close', () => {
        win2?.webContents.session.cookies.get({url: 'https://www.bilibili.com'}).then((cookies) => {
            // 这里拿到 cookie 了，就可以做一些事情了（嘿嘿）
            COOKIES = cookies;
        });
    })

import fetchCookie from 'fetch-cookie';

const fetchWithCookies = fetchCookie(fetch);

// 窗口关闭时尝试获取用户信息，并发送给渲染进程
    win2.on('closed', async () => {
        try {
            const response = await fetchWithCookies("https://api.bilibili.com/x/web-interface/nav", {
                headers: {
                    'Cookie': COOKIES.map((cookie: Cookie) => `${cookie.name}=${cookie.value}`).join('; ')
                }
            });

            const data = await response.json();
            if (data.code !== 0) {
                console.error(data);
                win1?.webContents.send('user-info', null);
                return;
            }
            win1?.webContents.send('user-info', data.data);
            uid = data.data.mid;
        } catch (error) {
            console.error('Error fetching user info:', error);
            win1?.webContents.send('user-info', null);
        }
    });

// 获取真实房间号
export async function getRoomId(shortId: string): Promise<number> {
    const response = await fetch(`https://api.live.bilibili.com/room/v1/Room/room_init?id=${shortId}`);
    const data = await response.json() as RoomInitResponse;
    console.log("获取真实房间号", data.data.room_id);
    return data.data.room_id;
}

// 获取消息流服务器和密钥
export async function getDanmuInfo(roomId: number): Promise<DanmuInfoResponse['data']> {
    // 这里请求的时候需要带上全部的 cookie，否则拿到的 key 无法登录使用（！小坑）
    const response = await fetchWithCookies(`https://api.live.bilibili.com/xlive/web-room/v1/index/getDanmuInfo?id=${roomId}`, {
        headers: {
            'Cookie': getCookies().map((cookie: Cookie) => `${cookie.name}=${cookie.value}`).join('; ')
        }
    });
    const data = await response.json() as DanmuInfoResponse;
    // console.log("获取消息流服务器和密钥", data.data);
    return data.data;
}

const roomId = await getRoomId(shortId);
    const danmuInfo = await getDanmuInfo(roomId);
    console.log("socket服务器地址", `wss://${danmuInfo.host_list[0].host}:${danmuInfo.host_list[0].wss_port}/sub`);

    // 为 ws 设置 userAgent
    const ws = new WebSocket(`wss://${danmuInfo.host_list[0].host}:${danmuInfo.host_list[0].wss_port}/sub`, {
        headers: {
            'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36'
        }
    });

    ws.on('open', () => {
        console.log('WebSocket 连接成功');
        sendCertificate(ws, roomId, danmuInfo.token, getUid(), getBuvid3());
    });

    ws.on('message', (data) => {
        handleWebSocketMessages(ws, data);
    });

// 生成鉴权包
function generateCertificate(roomId: number, token: string, _uid: number, buvid: string): Buffer {
    // console.log("生成鉴权包", roomId, token, uid, buvid);
    const headerLength = 16;
    const protocol = 1;
    const type = 7;
    const sequence = 2;
    const body = JSON.stringify({
        uid: _uid,
        roomid: roomId,
        protover: 2, // 这里协议版本一定要是 2，否则无法解析数据！哭，3 还不行
        buvid: buvid,
        platform: 'web',
        type: 2,
        key: token,
    });

    // console.log("生成鉴权包", body);

    const bodyBuffer = Buffer.from(body);
    const headerBuffer = Buffer.alloc(headerLength);
    headerBuffer.writeUInt32BE(headerLength + bodyBuffer.length, 0);
    headerBuffer.writeUInt16BE(headerLength, 4);
    headerBuffer.writeUInt16BE(protocol, 6);
    headerBuffer.writeUInt32BE(type, 8);
    headerBuffer.writeUInt32BE(sequence, 12);

    return Buffer.concat([headerBuffer, bodyBuffer]);
}

class DanmuExtractor extends EventEmitter {
    async getDmMsg(data: Buffer) {
        // console.log(data.toString('hex'));
        // 获取数据包长度，协议类型和操作类型
        const packetLen = parseInt(data.slice(0, 4).toString('hex'), 16);
        const proto = parseInt(data.slice(6, 8).toString('hex'), 16);
        const op = parseInt(data.slice(8, 12).toString('hex'), 16);

        // 若数据包是连着的，则根据第一个数据包的长度进行切分
        if (data.length > packetLen) {
            this.getDmMsg(data.slice(packetLen));
            data = data.slice(0, packetLen);
        }

        // 判断协议类型，若为 2 则用 zlib 解压
        if (proto === 2) {
            // console.log("解压数据");
            data = zlib.inflateSync(data.slice(16));
            this.getDmMsg(data);
            return;
        }

        if (op === 3) {
            console.info("HeartBeat");
        }

        // 判断消息类型
        if (op === 5) {
            try {
                // 解析 json
                // console.log("解析数据");
                const content = JSON.parse(data.slice(16).toString());
                // 发送数据
                this.emit('MsgData', content);
            } catch (e) {
                console.error(`[GETDATA ERROR]: ${e}`);
            }
        }
    }
}

export default DanmuExtractor;