Mostly working handshake handler & MOTD handler

This commit is contained in:
q13x 2022-12-20 11:29:33 -08:00
parent 958a060115
commit 083762fce1

232
utils.ts
View File

@ -1,25 +1,31 @@
import { v3 } from "uuid"
import WebSocket from "ws"
import { ProxiedPlayer } from "./classes.js"
import {
encodeULEB128 as encodeVarInt,
decodeULEB128 as decodeVarInt,
encodeSLEB128 as encodeSVarInt,
decodeSLEB128 as decodeSVarInt
} from "@thi.ng/leb128"
import { DisconnectReason, EaglerPacketId, MAGIC_ENDING_IDENTIFYS_BYTES } from "./eaglerPacketDef.js"
import { DisconnectReason, EAGLERCRAFT_SKIN_CHANNEL_NAME, EaglerPacketId, MAGIC_BUILTIN_SKIN_BYTES, MAGIC_ENDING_IDENTIFY_S_BYTES } from "./eaglerPacketDef.js"
import { Logger } from "./logger.js"
import { State } from "./types.js"
import { toBuffer } from "uuid-buffer"
import { ChannelMessageType, Chat, ChatColor, ProxiedPlayer, State, UUID } from "./types.js"
import { toBuffer, toString as uuidToString } from "uuid-buffer"
import * as mc from "minecraft-protocol"
import { config } from "./config.js"
import sharp from "sharp"
import { createHash, randomUUID } from "crypto"
import { encodeSSkinDl, encodeSSkinDlBuiltin, packChannelMessage, processClientReqPacket } from "./eaglerSkin.js"
const MAGIC_UUID = "a7e774bc-7ea4-11ed-9a58-1f9e14304a59"
const logger = new Logger("LoginHandler")
const USERNAME_REGEX = /[^0-9^a-z^A-Z^_]/gi
export function genUUID(user: string): string {
return v3(user, MAGIC_UUID)
const str = `OfflinePlayer:${user}`
let md5Bytes = createHash('md5').update(str).digest()
md5Bytes[6] &= 0x0f; /* clear version */
md5Bytes[6] |= 0x30; /* set to version 3 */
md5Bytes[8] &= 0x3f; /* clear variant */
md5Bytes[8] |= 0x80; /* set to IETF variant */
return uuidToString(md5Bytes)
}
export function bufferizeUUID(uuid: string): Buffer {
@ -33,17 +39,30 @@ export function validateUsername(user: string): void | never {
throw new Error("Invalid username. Username can only contain alphanumeric characters, and the underscore (_) character.")
}
export function disconnect(player: ProxiedPlayer, message: string, code?: DisconnectReason) {
export function chatToPlainString(chat: Chat): string {
let ret = ''
if (chat.text != null) ret += chat.text
if (chat.extra != null) {
chat.extra.forEach(extra => {
ret += extra.text
})
}
return ret
}
export function disconnect(player: ProxiedPlayer, message: Chat | string, code?: DisconnectReason) {
if (player.state == State.POST_HANDSHAKE) {
const messageLen = encodeVarInt(message.length)
const d = Buffer.alloc(1 + messageLen.length + message.length)
d.set([0x40, ...messageLen, ...Buffer.from(message)])
const message_m = (typeof message == 'string' ? JSON.stringify({ text: message }) : JSON.stringify(message)) + 0x0
const messageLen = encodeVarInt(message_m.length)
const d = Buffer.alloc([0x40, ...messageLen, ...Buffer.from(message_m)].length)
d.set([0x40, ...messageLen, ...Buffer.from(message_m)])
player.ws.send(d)
player.ws.close()
} else {
const messageLen = encodeVarInt(message.length), codeEnc = encodeVarInt(code ?? DisconnectReason.CUSTOM)
const d = Buffer.alloc(1 + codeEnc.length + messageLen.length + message.length)
d.set([0xff,...codeEnc, ...messageLen, ...Buffer.from(message)])
const message_m = (typeof message == 'string' ? message : chatToPlainString(message))
const messageLen = encodeVarInt(message_m.length), codeEnc = encodeVarInt(code ?? DisconnectReason.CUSTOM)
const d = Buffer.alloc([0xff,...codeEnc, ...messageLen, ...Buffer.from(message_m)].length)
d.set([0xff,...codeEnc, ...messageLen, ...Buffer.from(message_m)])
player.ws.send(d)
player.ws.close()
}
@ -88,7 +107,7 @@ export function awaitPacket(ws: WebSocket, id?: EaglerPacketId): Promise<Buffer>
export function loginServer(ip: string, port: number, client: ProxiedPlayer) {
return new Promise<void>((res, rej) => {
let receivedCompression = false
let blockedSuccessLogin = false
const mcClient = mc.createClient({
host: ip,
port: port,
@ -100,28 +119,20 @@ export function loginServer(ip: string, port: number, client: ProxiedPlayer) {
mcClient.end()
rej(err)
})
mcClient.on('end', () => {
client.ws.close()
})
mcClient.on('connect', () => {
client.remoteConnection = mcClient
mcClient.on('end', () => {
client.ws.close()
})
logger.info(`Player ${client.username} has been connected to the server.`)
res()
})
mcClient.on('raw', p => {
if (p[0] == 0x03 && !receivedCompression) {
receivedCompression = true
const compT = {
id: null,
thres: null
}
const id = decodeVarInt(p)
compT.id = Number(id[0])
const thres = decodeSVarInt(p.subarray(id[1]))
compT.thres = thres[0]
client.compressionThreshold = compT.thres
// block the login success packet to fix the bug that prints the UUID in chat on join
if (p[0] == 0x02 && blockedSuccessLogin) {
client.ws.send(p)
} else if (p[0] == 0x02) {
blockedSuccessLogin = !blockedSuccessLogin
} else {
client.ws.send(p)
}
@ -136,11 +147,10 @@ export async function doHandshake(client: ProxiedPlayer, initialPacket: Buffer)
client.remoteConnection.end()
}
PROXY.players.delete(client.username)
PROXY.playerStats.onlineCount -= 1
logger.info(`Client [/${client.ip}:${client.remotePort}]${client.username ? ` (${client.username})` : ""} disconnected from the server.`)
})
if (PROXY.players.size + 1 > PROXY.playerStats.max) {
disconnect(client, "The proxy is full!", DisconnectReason.CUSTOM)
if (PROXY.players.size + 1 > PROXY.config.maxPlayers) {
disconnect(client, ChatColor.YELLOW + "The proxy is full!", DisconnectReason.CUSTOM)
return
}
const identifyC = {
@ -164,8 +174,8 @@ export async function doHandshake(client: ProxiedPlayer, initialPacket: Buffer)
if (true) {
const brandingLen = encodeVarInt(PROXY.brand.length), brand = PROXY.brand
const verLen = encodeVarInt(PROXY.version.length), version = PROXY.version
const buff = Buffer.alloc(2 + MAGIC_ENDING_IDENTIFYS_BYTES.length + brandingLen.length + brand.length + verLen.length + version.length)
buff.set([EaglerPacketId.IDENTIFY_SERVER, 0x01, ...brandingLen, ...Buffer.from(brand), ...verLen, ...Buffer.from(version), ...Buffer.from(MAGIC_ENDING_IDENTIFYS_BYTES)])
const buff = Buffer.alloc(2 + MAGIC_ENDING_IDENTIFY_S_BYTES.length + brandingLen.length + brand.length + verLen.length + version.length)
buff.set([EaglerPacketId.IDENTIFY_SERVER, 0x01, ...brandingLen, ...Buffer.from(brand), ...verLen, ...Buffer.from(version), ...Buffer.from(MAGIC_ENDING_IDENTIFY_S_BYTES)])
client.ws.send(buff)
}
client.clientBrand = identifyC.branding
@ -181,61 +191,189 @@ export async function doHandshake(client: ProxiedPlayer, initialPacket: Buffer)
if (login[0] === EaglerPacketId.LOGIN) {
const Iid = decodeVarInt(login)
loginP.id = Number(Iid[0])
const usernameLen = decodeVarInt(login.subarray(loginP[1]))
const usernameLen = decodeVarInt(login.subarray(Iid[1]))
loginP.usernameLen = Number(usernameLen[0])
loginP.username = login.subarray(Iid[1] + usernameLen[1], Iid[1] + usernameLen[1] + loginP.usernameLen).toString()
const randomStrLen = decodeVarInt(login.subarray(Iid[1] + usernameLen[1] + loginP.usernameLen))
loginP.randomStrLen = Number(randomStrLen[0])
loginP.randomStr = login.subarray(Iid[1] + usernameLen[1] + loginP.usernameLen + randomStrLen[1], Iid[1] + usernameLen[1] + loginP.usernameLen + randomStrLen[1] + loginP.randomStrLen).toString()
client.username = loginP.username
client.uuid = genUUID(client.username)
try { validateUsername(client.username) }
catch (err) {
disconnect(client, err.message, DisconnectReason.BAD_USERNAME)
disconnect(client, ChatColor.RED + err.message, DisconnectReason.CUSTOM)
return
}
if (PROXY.players.has(client.username)) {
disconnect(client, `Duplicate username: ${client.username}. Please connect under a different username.`, DisconnectReason.DUPLICATE_USERNAME)
disconnect(client, `Duplicate username: ${client.username}. Please connect under a different username.`, DisconnectReason.CUSTOM)
return
}
PROXY.players.set(client.username, client)
if (true) {
const usernameLen = encodeVarInt(client.username.length), username = client.username
const uuidLen = encodeVarInt(client.uuid.length), uuid = client.uuid
const buff = Buffer.alloc(1 + usernameLen.length + username.length + uuidLen.length + uuid.length)
buff.set([EaglerPacketId.LOGIN_ACK, ...usernameLen, ...Buffer.from(username), ...uuidLen, ...Buffer.from(uuid)])
const uuid = bufferizeUUID(client.uuid)
const buff = Buffer.alloc(1 + usernameLen.length + username.length + uuid.length)
buff.set([EaglerPacketId.LOGIN_ACK, ...usernameLen, ...Buffer.from(username), ...Buffer.from(uuid)])
client.ws.send(buff)
if (true) {
const [skin, ready] = await Promise.all([awaitPacket(client.ws, EaglerPacketId.SKIN), awaitPacket(client.ws, EaglerPacketId.C_READY)])
if (ready[0] != 0x08) {
logger.error(`Client [/${client.ip}:${client.remotePort}] sent an unexpected packet! Disconnecting.`)
disconnect(client, "Received bad packet", DisconnectReason.UNEXPECTED_PACKET)
disconnect(client, ChatColor.RED + "Received bad packet.", DisconnectReason.CUSTOM)
client.ws.close()
return
}
if (true) {
const skinP = {
id: null,
skinVerLen: null,
skinVer: null, // skin_v1
type: null, // CUSTOM or BUILTIN
skinId: null,
skinDimens: null,
skin: null
}
const Iid = decodeVarInt(skin)
skinP.id = Number(Iid[0])
const skinVerLen = decodeVarInt(skin.subarray(Iid[1]))
skinP.skinVerLen = Number(skinVerLen[0])
skinP.skinVer = skin.subarray(Iid[1] + skinVerLen[1], Iid[1] + skinVerLen[1] + skinP.skinVerLen).toString()
const typebuff = skin.subarray(Iid[1] + skinVerLen[1] + skinP.skinVerLen, Iid[1] + skinVerLen[1] + skinP.skinVerLen + MAGIC_BUILTIN_SKIN_BYTES.length)
if (typebuff.compare(Buffer.from(MAGIC_BUILTIN_SKIN_BYTES)) == 0) {
skinP.type = "BUILTIN"
skinP.skinId = Number(decodeVarInt(skin.subarray(Iid[1] + skinVerLen[1] + skinP.skinVerLen + MAGIC_BUILTIN_SKIN_BYTES.length))[0])
} else {
skinP.type = "CUSTOM"
const skinSqrt = decodeVarInt(skin.subarray(Iid[1] + skinVerLen[1] + skinP.skinVerLen)), dimensions = Number(skinSqrt[0]) * Number(skinSqrt[0]) * 3
skinP.skinDimens = dimensions
skinP.skin = skin.subarray(Iid[1] + skinVerLen[1] + skinP.skinVerLen + skinSqrt[1] + 16)
console.log(skinP.skin.length)
if (skinP.skin.length > 16385) {
disconnect(client, ChatColor.RED + "Invalid skin received!")
return
}
console.log(skinP.skin[skinP.skin.length - 1])
}
client.skin = {
type: skinP.type,
skinId: skinP.skinId,
customSkin: skinP.skin
}
}
const buff = Buffer.alloc(1)
buff.set([EaglerPacketId.COMPLETE_HANDSHAKE])
client.ws.send(buff)
client.state = State.POST_HANDSHAKE
PROXY.playerStats.onlineCount += 1
logger.info(`Client [/${client.ip}:${client.remotePort}] authenticated as player "${client.username}" and passed handshake. Connecting!`)
logger.info(`Client [/${client.ip}:${client.remotePort}] authenticated as player ${client.username} (${client.uuid}) and passed handshake. Connecting!`)
try { await loginServer(config.server.host, config.server.port, client) }
catch (err) {
logger.error(`Could not connect to remote server at [/${config.server.host}:${config.server.port}]: ${err}`)
disconnect(client, "Failed to connect to server. Please try again later.", DisconnectReason.CUSTOM)
disconnect(client, ChatColor.RED + "Failed to connect to server. Please try again later.", DisconnectReason.CUSTOM)
client.state = State.DISCONNECTED
client.ws.close()
return
}
if (client.queuedEaglerSkinPackets.length > 0) {
for (const packet of client.queuedEaglerSkinPackets) {
processClientReqPacket(packet, client)
}
}
}
}
} else {
logger.error(`Client [/${client.ip}:${client.remotePort}] sent an unexpected packet! Disconnecting.`)
disconnect(client, "Received bad packet", DisconnectReason.UNEXPECTED_PACKET)
disconnect(client, ChatColor.RED + "Received bad packet", DisconnectReason.CUSTOM)
client.ws.close()
}
}
export type MotdPlayer = {
name: string,
id: UUID
}
export type MotdJSONRes = {
brand: string,
cracked: true,
data: {
cache: true,
icon: boolean,
max: number,
motd: [string, string],
online: number,
players: string[],
},
name: string,
secure: false,
time: ReturnType<typeof Date.now>,
type: "motd",
uuid: ReturnType<typeof randomUUID>,
vers: string
}
// a 16384 byte array
export type MotdServerLogo = Buffer
const ICON_SQRT = 64
export function generateMOTDImage(file: Buffer): Promise<MotdServerLogo> {
return new Promise<MotdServerLogo>((res, rej) => {
sharp(file)
.resize(ICON_SQRT, ICON_SQRT, {
kernel: 'nearest'
})
.raw({
depth: 'uchar'
})
.toBuffer()
.then(buff => {
for (const pixel of buff) {
if ((pixel & 0xFFFFFF) == 0) {
buff[buff.indexOf(pixel)] = 0
}
}
res(buff)
})
.catch(rej)
})
}
export function handleMotd(player: Partial<ProxiedPlayer>) {
const names = []
for (const [username, player] of PROXY.players) {
if (names.length > 0) {
names.push(`${ChatColor.GRAY}${ChatColor.ITALIC}(and ${PROXY.players.size - names.length} more)`)
break
} else {
names.push(username)
}
}
player.ws.send(JSON.stringify({
brand: PROXY.brand,
cracked: true,
data: {
cache: true,
icon: PROXY.MOTD.icon ? true : false,
max: PROXY.config.maxPlayers,
motd: PROXY.MOTD.motd,
online: PROXY.players.size,
players: names
},
name: PROXY.serverName,
secure: false,
time: Date.now(),
type: "motd",
uuid: PROXY.proxyUUID,
vers: PROXY.MOTDVersion
} as MotdJSONRes))
if (PROXY.MOTD.icon) {
player.ws.send(PROXY.MOTD.icon)
}
player.ws.close()
}