Provide interface for using not at all supported alternative accounts. (#1026)

* Handle auth potentially being an function

* "Simple" example of how in theroy it would work

* Add package.json

* Fix lint

* add type declarations

* Remove mcleaks example

* Add doc changes

* adjust warning

* Fix lint from rebase manual edit.

docs/API.md

@@ -93,7 +93,7 @@ Returns a `Client` instance and perform login.
 `options` is an object containing the properties :
  * username
  * port : default to 25565
- * auth : the type of account to use, either `microsoft`, `mojang`, or `offline`. default to 'offline'
+ * auth : the type of account to use, either `microsoft`, `mojang`, `offline` or `function (client, options) => void`. defaults to 'offline'.
  * password : can be omitted
    * (microsoft account) leave this blank to use device code auth. If you provide
    a password, we try to do username and password auth, but this does not always work.

docs/FAQ.md

@@ -1,20 +1,29 @@
-## FAQ
+# FAQ
 
 This Frequently Asked Question document is meant to help people for the most common things.
 
-### How to hide errors ?
+## How to hide errors ?
 
 Use `hideErrors: true` in createClient options
 You may also choose to add these listeners :
+
 ```js
 client.on('error', () => {})
 client.on('end', () => {})
 ```
 
-### How can I make a proxy with this ?
+## How can I make a proxy with this ?
 
-* Check out our WIP proxy lib https://github.com/PrismarineJS/prismarine-proxy
-* See this example https://github.com/PrismarineJS/node-minecraft-protocol/tree/master/examples/proxy
-* Read this issue https://github.com/PrismarineJS/node-minecraft-protocol/issues/712
-* check out https://github.com/Heath123/pakkit
-* Check out this app https://github.com/wvffle/minecraft-packet-debugger
+* Check out our WIP proxy lib <https://github.com/PrismarineJS/prismarine-proxy>
+* See this example <https://github.com/PrismarineJS/node-minecraft-protocol/tree/master/examples/proxy>
+* Read this issue <https://github.com/PrismarineJS/node-minecraft-protocol/issues/712>
+* check out <https://github.com/Heath123/pakkit>
+* Check out this app <https://github.com/wvffle/minecraft-packet-debugger>
+
+## Can you support alternative auth methods?
+
+Supporting alternative authentcation methods has been a long standing issue with Prismarine for awhile. We do add support for using your own custom authentication method by providing a function to the `options.auth` property. In order to keep the legitimacy of the project, and to prevent bad attention from Mojang, we will not be supporting any custom authentication methods in the official repositories.
+
+It is up to the end user to support and maintain the authentication protocol if this is used as support in many of the official channels will be limited.
+
+If you still wish to proceed, please make sure to throughly read and attempt to understand all implementations of the authentcation you wish to implement. Using an non-official authentication server can make you vulnerable to all different kinds of attacks which are not limited to insecure and/or malicious code! We will not be held responsible for anything you mess up.

examples/client_custom_auth/client_custom_auth.js

@@ -0,0 +1,41 @@
+'use strict'
+
+const mc = require('minecraft-protocol')
+
+const [, , host, port, username, password] = process.argv
+if (!username || !password) {
+  console.log('Usage : node client_custom_auth.js <host> <port> <username/email> [<password>]')
+  process.exit(1)
+}
+
+const client = mc.createClient({
+  host,
+  port: parseInt(port),
+  username: username,
+  password: password,
+  sessionServer: '', // URL to your session server proxy that changes the expected result of mojang's seession server to mcleaks expected.
+  // For more information: https://github.com/PrismarineJS/node-yggdrasil/blob/master/src/Server.js#L19
+  auth: async (client, options) => {
+    // handle custom authentication your way.
+
+    // client.username = options.username
+    // options.accessToken =
+    return options.connect(client)
+  }
+})
+
+client.on('connect', function () {
+  console.info('connected')
+})
+client.on('disconnect', function (packet) {
+  console.log('disconnected: ' + packet.reason)
+})
+client.on('chat', function (packet) {
+  const jsonMsg = JSON.parse(packet.message)
+  if (jsonMsg.translate === 'chat.type.announcement' || jsonMsg.translate === 'chat.type.text') {
+    const username = jsonMsg.with[0].text
+    const msg = jsonMsg.with[1]
+    if (username === client.username) return
+    client.write('chat', { message: msg })
+  }
+})

examples/client_custom_auth/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "node-minecraft-protocol-example-client-custom-auth",
+  "version": "0.0.0",
+  "description": "A node-minecraft-protocol example",
+  "main": "client_custom_auth.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": ""
+}

src/createClient.js

@@ -34,6 +34,9 @@ function createClient (options) {
   const client = new Client(false, version.minecraftVersion, options.customPackets, hideErrors)
 
   tcpDns(client, options)
+  if (options.auth instanceof Function) {
+    options.auth(client, options)
+  } else {
     switch (options.auth) {
       case 'mojang':
         console.warn('[deprecated] mojang auth servers no longer accept mojang accounts to login. convert your account.\nhttps://help.minecraft.net/hc/en-us/articles/4403181904525-How-to-Migrate-Your-Mojang-Account-to-a-Microsoft-Account')
@@ -48,6 +51,7 @@ function createClient (options) {
         options.connect(client)
         break
     }
+  }
   if (options.version === false) autoVersion(client, options)
   setProtocol(client, options)
   keepalive(client, options)

src/index.d.ts

@@ -101,7 +101,7 @@ declare module 'minecraft-protocol' {
 	export interface ClientOptions {
 		username: string
 		port?: number
-		auth?: 'mojang' | 'microsoft' | 'offline'
+		auth?: 'mojang' | 'microsoft' | 'offline' | ((client: Client, options: ClientOptions) => void)
 		password?: string
 		host?: string
 		clientToken?: string