Refactor the not-yet-working AimeDB impl

src/aimedb.js

@@ -0,0 +1,130 @@
+const crypto = require('crypto')
+const { Transform, pipeline } = require('stream')
+
+const K = Buffer.from('Copyright(C)SEGA', 'utf8')
+
+class Decoder extends Transform {
+  constructor(options) {
+    super({
+      readableObjectMode: true,
+      ...options,
+    })
+
+    this.state = Buffer.alloc(0)
+  }
+
+  _transform(chunk, encoding, callback) {
+    this.state = Buffer.concat([ this.state, chunk ])
+
+    if (this.state.length < 8) {
+      return
+    }
+
+    const magic = this.state.readUInt16LE(0)
+
+    if (magic != 0xA13E) {
+      return callback(new Error(`Invalid magic (decimal ${magic})`))
+    }
+
+    const len = this.state.readUInt16LE(6)
+
+    if (this.state.length < len) {
+      return
+    }
+
+    console.log('Aimedb: Recv', this.state)
+
+    const cmd = this.state.readUInt16LE(4)
+    const payload = this.state.slice(8, len)
+
+    this.state = this.state.slice(len)
+
+    return callback(null, { cmd, payload })
+  }
+}
+
+class Encoder extends Transform {
+  constructor(options) {
+    super({
+      writableObjectMode: true,
+      ...options
+    })
+  }
+
+  _transform(chunk, encoding, callback) {
+    const { cmd, payload } = chunk
+
+    // Message size must be rounded up to a multiple of 16
+
+    const len = 8 + payload.length
+    const buf = Buffer.alloc((len + 15) & ~15)
+
+    buf.writeUInt16LE(0xA13E, 0) // Magic?
+    buf.writeUInt16LE(0x3087, 2) // ???
+    buf.writeUInt16LE(cmd, 4)
+    buf.writeUInt16LE(buf.length, 6)
+    payload.copy(buf, 8)
+
+    console.log('Aimedb: Send', buf)
+
+    callback(null, buf)
+  }
+}
+
+async function dispatch(socket) {
+  console.log('Aimedb: Connection opened')
+
+  const input = pipeline(
+    socket,
+    crypto
+      .createDecipheriv('aes-128-ecb', K, null)
+      .setAutoPadding(false),
+    new Decoder(),
+  )
+
+
+  const output = new Encoder()
+
+  pipeline(
+    output,
+    crypto
+      .createCipheriv('aes-128-ecb', K, null)
+      .setAutoPadding(false),
+    socket,
+  )
+
+  try {
+    for await (const req of input) {
+      let payload
+
+      switch (req.cmd) {
+      case 0x0064:
+        console.log('Aimedb: Hello')
+
+        payload = Buffer.alloc(24)
+        payload.writeInt16LE(0x0001, 0)
+
+        output.write({ cmd: 0x0065, payload })
+
+        break
+
+      case 0x0066:
+        console.log('Aimedb: Goodbye')
+
+        break
+
+      default:
+        console.log('Aimedb: Unknown command', req.cmd)
+
+        break
+      }
+    }
+  } catch (e) {
+    console.log('Aimedb: Connection error:\n', e)
+  }
+
+  console.log('Aimedb: Connection closed')
+  socket.end()
+}
+
+module.exports = dispatch

src/index.js

@@ -1,10 +1,11 @@
+const fs = require('fs')
 const https = require('https')
 const http = require('http')
-const fs = require('fs')
 const net = require('net')
+
+const aimedb = require('./aimedb')
 const billing = require('./billing')
 const startup = require('./startup')
-const crypto = require('crypto')
 const title = require('./title')
 
 const tls = {
@@ -12,63 +13,7 @@ const tls = {
     key: fs.readFileSync('pki/server.key'),
 }
 
-function encodeAimeBody(buf) {
-   const keyBuf = Buffer.from('Copyright(C)SEGA', 'utf8')
-   const ivBuf = Buffer.from('0x00', 'hex')
-   let cipher = crypto.createCipheriv('aes-128-ecb', keyBuf, ivBuf)
-   cipher.setAutoPadding(false)
-   crypted = Buffer.concat([cipher.update(buf), cipher.final()])
-   return crypted
-}
-function decodeAimeBody(buf) {
-   const keyBuf = Buffer.from('Copyright(C)SEGA', 'utf8')
-   const ivBuf = Buffer.from('0x00', 'hex')
-   let decipher = crypto.createDecipheriv('aes-128-ecb', keyBuf, ivBuf)
-   decipher.setAutoPadding(false)
-   decrypted = Buffer.concat([decipher.update(buf), decipher.final()])
-   return decrypted
-}
-function parseMessage(buf) {
-   switch(buf[4].toString(16)) {
-      case "64":
-	var newBuffer = new Buffer.from([0x3e, 0xa1, 0x87, 0x30, 0x65, 0x00, 0x20, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00]);
-	console.log(newBuffer)
-	return newBuffer
-	break;
-      case "66":
-	var newBuffer = new Buffer.from([0x3e, 0xa1, 0x87, 0x30, 0x67, 0x00, 0x20, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00]);
-	console.log(newBuffer)
-	return newBuffer
-	break;
-      default:
-        console.log("No case for "+buf[4].toString(16))
-	return null
-   }
-
-}
-
-const server = net.createServer((c) => {
-  // 'connection' listener
-  console.log('client connected');
-  c.on('end', () => {
-    console.log('client disconnected');
-  });
-  c.on('error', (err) => { throw err; });
-  c.on('data', (data) => {
-    decode = decodeAimeBody(data);
-    encode = encodeAimeBody(decodeAimeBody(data)).toString('hex')+'\r\n'
-    console.log('Decode: '+decode.toString('hex'))
-    c.write(encodeAimeBody(parseMessage(decode)))
-  });
-    c.pipe(c);
-});
-server.on('error', (err) => {
-  throw err;
-});
-server.listen(22345, () => {
-  console.log('server bound');
-});
-
+net.createServer(aimedb).listen(22345)
 http.createServer(startup).listen(80)
 https.createServer(tls, billing).listen(8443)
 http.createServer(title).listen(9000)