1 files changed, 555 insertions, 0 deletions
diff --git a/node_modules/ws/lib/Receiver.js b/node_modules/ws/lib/Receiver.js
new file mode 100644
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+++ b/node_modules/ws/lib/Receiver.js
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+/*!
+ * ws: a node.js websocket client
+ * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+ * MIT Licensed
+ */
+
+'use strict';
+
+const safeBuffer = require('safe-buffer');
+
+const PerMessageDeflate = require('./PerMessageDeflate');
+const isValidUTF8 = require('./Validation');
+const bufferUtil = require('./BufferUtil');
+const ErrorCodes = require('./ErrorCodes');
+const constants = require('./Constants');
+
+const Buffer = safeBuffer.Buffer;
+
+const GET_INFO = 0;
+const GET_PAYLOAD_LENGTH_16 = 1;
+const GET_PAYLOAD_LENGTH_64 = 2;
+const GET_MASK = 3;
+const GET_DATA = 4;
+const INFLATING = 5;
+
+/**
+ * HyBi Receiver implementation.
+ */
+class Receiver {
+  /**
+   * Creates a Receiver instance.
+   *
+   * @param {Object} extensions An object containing the negotiated extensions
+   * @param {Number} maxPayload The maximum allowed message length
+   * @param {String} binaryType The type for binary data
+   */
+  constructor (extensions, maxPayload, binaryType) {
+    this.binaryType = binaryType || constants.BINARY_TYPES[0];
+    this.extensions = extensions || {};
+    this.maxPayload = maxPayload | 0;
+
+    this.bufferedBytes = 0;
+    this.buffers = [];
+
+    this.compressed = false;
+    this.payloadLength = 0;
+    this.fragmented = 0;
+    this.masked = false;
+    this.fin = false;
+    this.mask = null;
+    this.opcode = 0;
+
+    this.totalPayloadLength = 0;
+    this.messageLength = 0;
+    this.fragments = [];
+
+    this.cleanupCallback = null;
+    this.hadError = false;
+    this.dead = false;
+    this.loop = false;
+
+    this.onmessage = null;
+    this.onclose = null;
+    this.onerror = null;
+    this.onping = null;
+    this.onpong = null;
+
+    this.state = GET_INFO;
+  }
+
+  /**
+   * Consumes bytes from the available buffered data.
+   *
+   * @param {Number} bytes The number of bytes to consume
+   * @return {Buffer} Consumed bytes
+   * @private
+   */
+  readBuffer (bytes) {
+    var offset = 0;
+    var dst;
+    var l;
+
+    this.bufferedBytes -= bytes;
+
+    if (bytes === this.buffers[0].length) return this.buffers.shift();
+
+    if (bytes < this.buffers[0].length) {
+      dst = this.buffers[0].slice(0, bytes);
+      this.buffers[0] = this.buffers[0].slice(bytes);
+      return dst;
+    }
+
+    dst = Buffer.allocUnsafe(bytes);
+
+    while (bytes > 0) {
+      l = this.buffers[0].length;
+
+      if (bytes >= l) {
+        this.buffers[0].copy(dst, offset);
+        offset += l;
+        this.buffers.shift();
+      } else {
+        this.buffers[0].copy(dst, offset, 0, bytes);
+        this.buffers[0] = this.buffers[0].slice(bytes);
+      }
+
+      bytes -= l;
+    }
+
+    return dst;
+  }
+
+  /**
+   * Checks if the number of buffered bytes is bigger or equal than `n` and
+   * calls `cleanup` if necessary.
+   *
+   * @param {Number} n The number of bytes to check against
+   * @return {Boolean} `true` if `bufferedBytes >= n`, else `false`
+   * @private
+   */
+  hasBufferedBytes (n) {
+    if (this.bufferedBytes >= n) return true;
+
+    this.loop = false;
+    if (this.dead) this.cleanup(this.cleanupCallback);
+    return false;
+  }
+
+  /**
+   * Adds new data to the parser.
+   *
+   * @public
+   */
+  add (data) {
+    if (this.dead) return;
+
+    this.bufferedBytes += data.length;
+    this.buffers.push(data);
+    this.startLoop();
+  }
+
+  /**
+   * Starts the parsing loop.
+   *
+   * @private
+   */
+  startLoop () {
+    this.loop = true;
+
+    while (this.loop) {
+      switch (this.state) {
+        case GET_INFO:
+          this.getInfo();
+          break;
+        case GET_PAYLOAD_LENGTH_16:
+          this.getPayloadLength16();
+          break;
+        case GET_PAYLOAD_LENGTH_64:
+          this.getPayloadLength64();
+          break;
+        case GET_MASK:
+          this.getMask();
+          break;
+        case GET_DATA:
+          this.getData();
+          break;
+        default: // `INFLATING`
+          this.loop = false;
+      }
+    }
+  }
+
+  /**
+   * Reads the first two bytes of a frame.
+   *
+   * @private
+   */
+  getInfo () {
+    if (!this.hasBufferedBytes(2)) return;
+
+    const buf = this.readBuffer(2);
+
+    if ((buf[0] & 0x30) !== 0x00) {
+      this.error(new Error('RSV2 and RSV3 must be clear'), 1002);
+      return;
+    }
+
+    const compressed = (buf[0] & 0x40) === 0x40;
+
+    if (compressed && !this.extensions[PerMessageDeflate.extensionName]) {
+      this.error(new Error('RSV1 must be clear'), 1002);
+      return;
+    }
+
+    this.fin = (buf[0] & 0x80) === 0x80;
+    this.opcode = buf[0] & 0x0f;
+    this.payloadLength = buf[1] & 0x7f;
+
+    if (this.opcode === 0x00) {
+      if (compressed) {
+        this.error(new Error('RSV1 must be clear'), 1002);
+        return;
+      }
+
+      if (!this.fragmented) {
+        this.error(new Error(`invalid opcode: ${this.opcode}`), 1002);
+        return;
+      } else {
+        this.opcode = this.fragmented;
+      }
+    } else if (this.opcode === 0x01 || this.opcode === 0x02) {
+      if (this.fragmented) {
+        this.error(new Error(`invalid opcode: ${this.opcode}`), 1002);
+        return;
+      }
+
+      this.compressed = compressed;
+    } else if (this.opcode > 0x07 && this.opcode < 0x0b) {
+      if (!this.fin) {
+        this.error(new Error('FIN must be set'), 1002);
+        return;
+      }
+
+      if (compressed) {
+        this.error(new Error('RSV1 must be clear'), 1002);
+        return;
+      }
+
+      if (this.payloadLength > 0x7d) {
+        this.error(new Error('invalid payload length'), 1002);
+        return;
+      }
+    } else {
+      this.error(new Error(`invalid opcode: ${this.opcode}`), 1002);
+      return;
+    }
+
+    if (!this.fin && !this.fragmented) this.fragmented = this.opcode;
+
+    this.masked = (buf[1] & 0x80) === 0x80;
+
+    if (this.payloadLength === 126) this.state = GET_PAYLOAD_LENGTH_16;
+    else if (this.payloadLength === 127) this.state = GET_PAYLOAD_LENGTH_64;
+    else this.haveLength();
+  }
+
+  /**
+   * Gets extended payload length (7+16).
+   *
+   * @private
+   */
+  getPayloadLength16 () {
+    if (!this.hasBufferedBytes(2)) return;
+
+    this.payloadLength = this.readBuffer(2).readUInt16BE(0, true);
+    this.haveLength();
+  }
+
+  /**
+   * Gets extended payload length (7+64).
+   *
+   * @private
+   */
+  getPayloadLength64 () {
+    if (!this.hasBufferedBytes(8)) return;
+
+    const buf = this.readBuffer(8);
+    const num = buf.readUInt32BE(0, true);
+
+    //
+    // The maximum safe integer in JavaScript is 2^53 - 1. An error is returned
+    // if payload length is greater than this number.
+    //
+    if (num > Math.pow(2, 53 - 32) - 1) {
+      this.error(new Error('max payload size exceeded'), 1009);
+      return;
+    }
+
+    this.payloadLength = (num * Math.pow(2, 32)) + buf.readUInt32BE(4, true);
+    this.haveLength();
+  }
+
+  /**
+   * Payload length has been read.
+   *
+   * @private
+   */
+  haveLength () {
+    if (this.opcode < 0x08 && this.maxPayloadExceeded(this.payloadLength)) {
+      return;
+    }
+
+    if (this.masked) this.state = GET_MASK;
+    else this.state = GET_DATA;
+  }
+
+  /**
+   * Reads mask bytes.
+   *
+   * @private
+   */
+  getMask () {
+    if (!this.hasBufferedBytes(4)) return;
+
+    this.mask = this.readBuffer(4);
+    this.state = GET_DATA;
+  }
+
+  /**
+   * Reads data bytes.
+   *
+   * @private
+   */
+  getData () {
+    var data = constants.EMPTY_BUFFER;
+
+    if (this.payloadLength) {
+      if (!this.hasBufferedBytes(this.payloadLength)) return;
+
+      data = this.readBuffer(this.payloadLength);
+      if (this.masked) bufferUtil.unmask(data, this.mask);
+    }
+
+    if (this.opcode > 0x07) {
+      this.controlMessage(data);
+    } else if (this.compressed) {
+      this.state = INFLATING;
+      this.decompress(data);
+    } else if (this.pushFragment(data)) {
+      this.dataMessage();
+    }
+  }
+
+  /**
+   * Decompresses data.
+   *
+   * @param {Buffer} data Compressed data
+   * @private
+   */
+  decompress (data) {
+    const extension = this.extensions[PerMessageDeflate.extensionName];
+
+    extension.decompress(data, this.fin, (err, buf) => {
+      if (err) {
+        this.error(err, err.closeCode === 1009 ? 1009 : 1007);
+        return;
+      }
+
+      if (this.pushFragment(buf)) this.dataMessage();
+      this.startLoop();
+    });
+  }
+
+  /**
+   * Handles a data message.
+   *
+   * @private
+   */
+  dataMessage () {
+    if (this.fin) {
+      const messageLength = this.messageLength;
+      const fragments = this.fragments;
+
+      this.totalPayloadLength = 0;
+      this.messageLength = 0;
+      this.fragmented = 0;
+      this.fragments = [];
+
+      if (this.opcode === 2) {
+        var data;
+
+        if (this.binaryType === 'nodebuffer') {
+          data = toBuffer(fragments, messageLength);
+        } else if (this.binaryType === 'arraybuffer') {
+          data = toArrayBuffer(toBuffer(fragments, messageLength));
+        } else {
+          data = fragments;
+        }
+
+        this.onmessage(data, { masked: this.masked, binary: true });
+      } else {
+        const buf = toBuffer(fragments, messageLength);
+
+        if (!isValidUTF8(buf)) {
+          this.error(new Error('invalid utf8 sequence'), 1007);
+          return;
+        }
+
+        this.onmessage(buf.toString(), { masked: this.masked });
+      }
+    }
+
+    this.state = GET_INFO;
+  }
+
+  /**
+   * Handles a control message.
+   *
+   * @param {Buffer} data Data to handle
+   * @private
+   */
+  controlMessage (data) {
+    if (this.opcode === 0x08) {
+      if (data.length === 0) {
+        this.onclose(1000, '', { masked: this.masked });
+        this.loop = false;
+        this.cleanup(this.cleanupCallback);
+      } else if (data.length === 1) {
+        this.error(new Error('invalid payload length'), 1002);
+      } else {
+        const code = data.readUInt16BE(0, true);
+
+        if (!ErrorCodes.isValidErrorCode(code)) {
+          this.error(new Error(`invalid status code: ${code}`), 1002);
+          return;
+        }
+
+        const buf = data.slice(2);
+
+        if (!isValidUTF8(buf)) {
+          this.error(new Error('invalid utf8 sequence'), 1007);
+          return;
+        }
+
+        this.onclose(code, buf.toString(), { masked: this.masked });
+        this.loop = false;
+        this.cleanup(this.cleanupCallback);
+      }
+
+      return;
+    }
+
+    const flags = { masked: this.masked, binary: true };
+
+    if (this.opcode === 0x09) this.onping(data, flags);
+    else this.onpong(data, flags);
+
+    this.state = GET_INFO;
+  }
+
+  /**
+   * Handles an error.
+   *
+   * @param {Error} err The error
+   * @param {Number} code Close code
+   * @private
+   */
+  error (err, code) {
+    this.onerror(err, code);
+    this.hadError = true;
+    this.loop = false;
+    this.cleanup(this.cleanupCallback);
+  }
+
+  /**
+   * Checks payload size, disconnects socket when it exceeds `maxPayload`.
+   *
+   * @param {Number} length Payload length
+   * @private
+   */
+  maxPayloadExceeded (length) {
+    if (length === 0 || this.maxPayload < 1) return false;
+
+    const fullLength = this.totalPayloadLength + length;
+
+    if (fullLength <= this.maxPayload) {
+      this.totalPayloadLength = fullLength;
+      return false;
+    }
+
+    this.error(new Error('max payload size exceeded'), 1009);
+    return true;
+  }
+
+  /**
+   * Appends a fragment in the fragments array after checking that the sum of
+   * fragment lengths does not exceed `maxPayload`.
+   *
+   * @param {Buffer} fragment The fragment to add
+   * @return {Boolean} `true` if `maxPayload` is not exceeded, else `false`
+   * @private
+   */
+  pushFragment (fragment) {
+    if (fragment.length === 0) return true;
+
+    const totalLength = this.messageLength + fragment.length;
+
+    if (this.maxPayload < 1 || totalLength <= this.maxPayload) {
+      this.messageLength = totalLength;
+      this.fragments.push(fragment);
+      return true;
+    }
+
+    this.error(new Error('max payload size exceeded'), 1009);
+    return false;
+  }
+
+  /**
+   * Releases resources used by the receiver.
+   *
+   * @param {Function} cb Callback
+   * @public
+   */
+  cleanup (cb) {
+    this.dead = true;
+
+    if (!this.hadError && (this.loop || this.state === INFLATING)) {
+      this.cleanupCallback = cb;
+    } else {
+      this.extensions = null;
+      this.fragments = null;
+      this.buffers = null;
+      this.mask = null;
+
+      this.cleanupCallback = null;
+      this.onmessage = null;
+      this.onclose = null;
+      this.onerror = null;
+      this.onping = null;
+      this.onpong = null;
+
+      if (cb) cb();
+    }
+  }
+}
+
+module.exports = Receiver;
+
+/**
+ * Makes a buffer from a list of fragments.
+ *
+ * @param {Buffer[]} fragments The list of fragments composing the message
+ * @param {Number} messageLength The length of the message
+ * @return {Buffer}
+ * @private
+ */
+function toBuffer (fragments, messageLength) {
+  if (fragments.length === 1) return fragments[0];
+  if (fragments.length > 1) return bufferUtil.concat(fragments, messageLength);
+  return constants.EMPTY_BUFFER;
+}
+
+/**
+ * Converts a buffer to an `ArrayBuffer`.
+ *
+ * @param {Buffer} The buffer to convert
+ * @return {ArrayBuffer} Converted buffer
+ */
+function toArrayBuffer (buf) {
+  if (buf.byteOffset === 0 && buf.byteLength === buf.buffer.byteLength) {
+    return buf.buffer;
+  }
+
+  return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
+}