Refactor and update RocketChat bridge

* Add support for editing/deleting messages
* Add support for uploading files
* Add support for avatars
* Use the Rocket.Chat.Go.SDK
* Use the rest and streaming api

9 files changed, 1329 insertions, 0 deletions

diff --git a/vendor/golang.org/x/net/AUTHORS b/vendor/golang.org/x/net/AUTHORS
new file mode 100644
index 00000000..15167cd7
--- /dev/null
+++ b/vendor/golang.org/x/net/AUTHORS
@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.
diff --git a/vendor/golang.org/x/net/CONTRIBUTORS b/vendor/golang.org/x/net/CONTRIBUTORS
new file mode 100644
index 00000000..1c4577e9
--- /dev/null
+++ b/vendor/golang.org/x/net/CONTRIBUTORS
@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.
diff --git a/vendor/golang.org/x/net/LICENSE b/vendor/golang.org/x/net/LICENSE
new file mode 100644
index 00000000..6a66aea5
--- /dev/null
+++ b/vendor/golang.org/x/net/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/golang.org/x/net/PATENTS b/vendor/golang.org/x/net/PATENTS
new file mode 100644
index 00000000..73309904
--- /dev/null
+++ b/vendor/golang.org/x/net/PATENTS
@@ -0,0 +1,22 @@
+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.
diff --git a/vendor/golang.org/x/net/websocket/client.go b/vendor/golang.org/x/net/websocket/client.go
new file mode 100644
index 00000000..69a4ac7e
--- /dev/null
+++ b/vendor/golang.org/x/net/websocket/client.go
@@ -0,0 +1,106 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+)
+
+// DialError is an error that occurs while dialling a websocket server.
+type DialError struct {
+	*Config
+	Err error
+}
+
+func (e *DialError) Error() string {
+	return "websocket.Dial " + e.Config.Location.String() + ": " + e.Err.Error()
+}
+
+// NewConfig creates a new WebSocket config for client connection.
+func NewConfig(server, origin string) (config *Config, err error) {
+	config = new(Config)
+	config.Version = ProtocolVersionHybi13
+	config.Location, err = url.ParseRequestURI(server)
+	if err != nil {
+		return
+	}
+	config.Origin, err = url.ParseRequestURI(origin)
+	if err != nil {
+		return
+	}
+	config.Header = http.Header(make(map[string][]string))
+	return
+}
+
+// NewClient creates a new WebSocket client connection over rwc.
+func NewClient(config *Config, rwc io.ReadWriteCloser) (ws *Conn, err error) {
+	br := bufio.NewReader(rwc)
+	bw := bufio.NewWriter(rwc)
+	err = hybiClientHandshake(config, br, bw)
+	if err != nil {
+		return
+	}
+	buf := bufio.NewReadWriter(br, bw)
+	ws = newHybiClientConn(config, buf, rwc)
+	return
+}
+
+// Dial opens a new client connection to a WebSocket.
+func Dial(url_, protocol, origin string) (ws *Conn, err error) {
+	config, err := NewConfig(url_, origin)
+	if err != nil {
+		return nil, err
+	}
+	if protocol != "" {
+		config.Protocol = []string{protocol}
+	}
+	return DialConfig(config)
+}
+
+var portMap = map[string]string{
+	"ws":  "80",
+	"wss": "443",
+}
+
+func parseAuthority(location *url.URL) string {
+	if _, ok := portMap[location.Scheme]; ok {
+		if _, _, err := net.SplitHostPort(location.Host); err != nil {
+			return net.JoinHostPort(location.Host, portMap[location.Scheme])
+		}
+	}
+	return location.Host
+}
+
+// DialConfig opens a new client connection to a WebSocket with a config.
+func DialConfig(config *Config) (ws *Conn, err error) {
+	var client net.Conn
+	if config.Location == nil {
+		return nil, &DialError{config, ErrBadWebSocketLocation}
+	}
+	if config.Origin == nil {
+		return nil, &DialError{config, ErrBadWebSocketOrigin}
+	}
+	dialer := config.Dialer
+	if dialer == nil {
+		dialer = &net.Dialer{}
+	}
+	client, err = dialWithDialer(dialer, config)
+	if err != nil {
+		goto Error
+	}
+	ws, err = NewClient(config, client)
+	if err != nil {
+		client.Close()
+		goto Error
+	}
+	return
+
+Error:
+	return nil, &DialError{config, err}
+}
diff --git a/vendor/golang.org/x/net/websocket/dial.go b/vendor/golang.org/x/net/websocket/dial.go
new file mode 100644
index 00000000..2dab943a
--- /dev/null
+++ b/vendor/golang.org/x/net/websocket/dial.go
@@ -0,0 +1,24 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"crypto/tls"
+	"net"
+)
+
+func dialWithDialer(dialer *net.Dialer, config *Config) (conn net.Conn, err error) {
+	switch config.Location.Scheme {
+	case "ws":
+		conn, err = dialer.Dial("tcp", parseAuthority(config.Location))
+
+	case "wss":
+		conn, err = tls.DialWithDialer(dialer, "tcp", parseAuthority(config.Location), config.TlsConfig)
+
+	default:
+		err = ErrBadScheme
+	}
+	return
+}
diff --git a/vendor/golang.org/x/net/websocket/hybi.go b/vendor/golang.org/x/net/websocket/hybi.go
new file mode 100644
index 00000000..8cffdd16
--- /dev/null
+++ b/vendor/golang.org/x/net/websocket/hybi.go
@@ -0,0 +1,583 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+// This file implements a protocol of hybi draft.
+// http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/rand"
+	"crypto/sha1"
+	"encoding/base64"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+const (
+	websocketGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
+
+	closeStatusNormal            = 1000
+	closeStatusGoingAway         = 1001
+	closeStatusProtocolError     = 1002
+	closeStatusUnsupportedData   = 1003
+	closeStatusFrameTooLarge     = 1004
+	closeStatusNoStatusRcvd      = 1005
+	closeStatusAbnormalClosure   = 1006
+	closeStatusBadMessageData    = 1007
+	closeStatusPolicyViolation   = 1008
+	closeStatusTooBigData        = 1009
+	closeStatusExtensionMismatch = 1010
+
+	maxControlFramePayloadLength = 125
+)
+
+var (
+	ErrBadMaskingKey         = &ProtocolError{"bad masking key"}
+	ErrBadPongMessage        = &ProtocolError{"bad pong message"}
+	ErrBadClosingStatus      = &ProtocolError{"bad closing status"}
+	ErrUnsupportedExtensions = &ProtocolError{"unsupported extensions"}
+	ErrNotImplemented        = &ProtocolError{"not implemented"}
+
+	handshakeHeader = map[string]bool{
+		"Host":                   true,
+		"Upgrade":                true,
+		"Connection":             true,
+		"Sec-Websocket-Key":      true,
+		"Sec-Websocket-Origin":   true,
+		"Sec-Websocket-Version":  true,
+		"Sec-Websocket-Protocol": true,
+		"Sec-Websocket-Accept":   true,
+	}
+)
+
+// A hybiFrameHeader is a frame header as defined in hybi draft.
+type hybiFrameHeader struct {
+	Fin        bool
+	Rsv        [3]bool
+	OpCode     byte
+	Length     int64
+	MaskingKey []byte
+
+	data *bytes.Buffer
+}
+
+// A hybiFrameReader is a reader for hybi frame.
+type hybiFrameReader struct {
+	reader io.Reader
+
+	header hybiFrameHeader
+	pos    int64
+	length int
+}
+
+func (frame *hybiFrameReader) Read(msg []byte) (n int, err error) {
+	n, err = frame.reader.Read(msg)
+	if frame.header.MaskingKey != nil {
+		for i := 0; i < n; i++ {
+			msg[i] = msg[i] ^ frame.header.MaskingKey[frame.pos%4]
+			frame.pos++
+		}
+	}
+	return n, err
+}
+
+func (frame *hybiFrameReader) PayloadType() byte { return frame.header.OpCode }
+
+func (frame *hybiFrameReader) HeaderReader() io.Reader {
+	if frame.header.data == nil {
+		return nil
+	}
+	if frame.header.data.Len() == 0 {
+		return nil
+	}
+	return frame.header.data
+}
+
+func (frame *hybiFrameReader) TrailerReader() io.Reader { return nil }
+
+func (frame *hybiFrameReader) Len() (n int) { return frame.length }
+
+// A hybiFrameReaderFactory creates new frame reader based on its frame type.
+type hybiFrameReaderFactory struct {
+	*bufio.Reader
+}
+
+// NewFrameReader reads a frame header from the connection, and creates new reader for the frame.
+// See Section 5.2 Base Framing protocol for detail.
+// http://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-17#section-5.2
+func (buf hybiFrameReaderFactory) NewFrameReader() (frame frameReader, err error) {
+	hybiFrame := new(hybiFrameReader)
+	frame = hybiFrame
+	var header []byte
+	var b byte
+	// First byte. FIN/RSV1/RSV2/RSV3/OpCode(4bits)
+	b, err = buf.ReadByte()
+	if err != nil {
+		return
+	}
+	header = append(header, b)
+	hybiFrame.header.Fin = ((header[0] >> 7) & 1) != 0
+	for i := 0; i < 3; i++ {
+		j := uint(6 - i)
+		hybiFrame.header.Rsv[i] = ((header[0] >> j) & 1) != 0
+	}
+	hybiFrame.header.OpCode = header[0] & 0x0f
+
+	// Second byte. Mask/Payload len(7bits)
+	b, err = buf.ReadByte()
+	if err != nil {
+		return
+	}
+	header = append(header, b)
+	mask := (b & 0x80) != 0
+	b &= 0x7f
+	lengthFields := 0
+	switch {
+	case b <= 125: // Payload length 7bits.
+		hybiFrame.header.Length = int64(b)
+	case b == 126: // Payload length 7+16bits
+		lengthFields = 2
+	case b == 127: // Payload length 7+64bits
+		lengthFields = 8
+	}
+	for i := 0; i < lengthFields; i++ {
+		b, err = buf.ReadByte()
+		if err != nil {
+			return
+		}
+		if lengthFields == 8 && i == 0 { // MSB must be zero when 7+64 bits
+			b &= 0x7f
+		}
+		header = append(header, b)
+		hybiFrame.header.Length = hybiFrame.header.Length*256 + int64(b)
+	}
+	if mask {
+		// Masking key. 4 bytes.
+		for i := 0; i < 4; i++ {
+			b, err = buf.ReadByte()
+			if err != nil {
+				return
+			}
+			header = append(header, b)
+			hybiFrame.header.MaskingKey = append(hybiFrame.header.MaskingKey, b)
+		}
+	}
+	hybiFrame.reader = io.LimitReader(buf.Reader, hybiFrame.header.Length)
+	hybiFrame.header.data = bytes.NewBuffer(header)
+	hybiFrame.length = len(header) + int(hybiFrame.header.Length)
+	return
+}
+
+// A HybiFrameWriter is a writer for hybi frame.
+type hybiFrameWriter struct {
+	writer *bufio.Writer
+
+	header *hybiFrameHeader
+}
+
+func (frame *hybiFrameWriter) Write(msg []byte) (n int, err error) {
+	var header []byte
+	var b byte
+	if frame.header.Fin {
+		b |= 0x80
+	}
+	for i := 0; i < 3; i++ {
+		if frame.header.Rsv[i] {
+			j := uint(6 - i)
+			b |= 1 << j
+		}
+	}
+	b |= frame.header.OpCode
+	header = append(header, b)
+	if frame.header.MaskingKey != nil {
+		b = 0x80
+	} else {
+		b = 0
+	}
+	lengthFields := 0
+	length := len(msg)
+	switch {
+	case length <= 125:
+		b |= byte(length)
+	case length < 65536:
+		b |= 126
+		lengthFields = 2
+	default:
+		b |= 127
+		lengthFields = 8
+	}
+	header = append(header, b)
+	for i := 0; i < lengthFields; i++ {
+		j := uint((lengthFields - i - 1) * 8)
+		b = byte((length >> j) & 0xff)
+		header = append(header, b)
+	}
+	if frame.header.MaskingKey != nil {
+		if len(frame.header.MaskingKey) != 4 {
+			return 0, ErrBadMaskingKey
+		}
+		header = append(header, frame.header.MaskingKey...)
+		frame.writer.Write(header)
+		data := make([]byte, length)
+		for i := range data {
+			data[i] = msg[i] ^ frame.header.MaskingKey[i%4]
+		}
+		frame.writer.Write(data)
+		err = frame.writer.Flush()
+		return length, err
+	}
+	frame.writer.Write(header)
+	frame.writer.Write(msg)
+	err = frame.writer.Flush()
+	return length, err
+}
+
+func (frame *hybiFrameWriter) Close() error { return nil }
+
+type hybiFrameWriterFactory struct {
+	*bufio.Writer
+	needMaskingKey bool
+}
+
+func (buf hybiFrameWriterFactory) NewFrameWriter(payloadType byte) (frame frameWriter, err error) {
+	frameHeader := &hybiFrameHeader{Fin: true, OpCode: payloadType}
+	if buf.needMaskingKey {
+		frameHeader.MaskingKey, err = generateMaskingKey()
+		if err != nil {
+			return nil, err
+		}
+	}
+	return &hybiFrameWriter{writer: buf.Writer, header: frameHeader}, nil
+}
+
+type hybiFrameHandler struct {
+	conn        *Conn
+	payloadType byte
+}
+
+func (handler *hybiFrameHandler) HandleFrame(frame frameReader) (frameReader, error) {
+	if handler.conn.IsServerConn() {
+		// The client MUST mask all frames sent to the server.
+		if frame.(*hybiFrameReader).header.MaskingKey == nil {
+			handler.WriteClose(closeStatusProtocolError)
+			return nil, io.EOF
+		}
+	} else {
+		// The server MUST NOT mask all frames.
+		if frame.(*hybiFrameReader).header.MaskingKey != nil {
+			handler.WriteClose(closeStatusProtocolError)
+			return nil, io.EOF
+		}
+	}
+	if header := frame.HeaderReader(); header != nil {
+		io.Copy(ioutil.Discard, header)
+	}
+	switch frame.PayloadType() {
+	case ContinuationFrame:
+		frame.(*hybiFrameReader).header.OpCode = handler.payloadType
+	case TextFrame, BinaryFrame:
+		handler.payloadType = frame.PayloadType()
+	case CloseFrame:
+		return nil, io.EOF
+	case PingFrame, PongFrame:
+		b := make([]byte, maxControlFramePayloadLength)
+		n, err := io.ReadFull(frame, b)
+		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
+			return nil, err
+		}
+		io.Copy(ioutil.Discard, frame)
+		if frame.PayloadType() == PingFrame {
+			if _, err := handler.WritePong(b[:n]); err != nil {
+				return nil, err
+			}
+		}
+		return nil, nil
+	}
+	return frame, nil
+}
+
+func (handler *hybiFrameHandler) WriteClose(status int) (err error) {
+	handler.conn.wio.Lock()
+	defer handler.conn.wio.Unlock()
+	w, err := handler.conn.frameWriterFactory.NewFrameWriter(CloseFrame)
+	if err != nil {
+		return err
+	}
+	msg := make([]byte, 2)
+	binary.BigEndian.PutUint16(msg, uint16(status))
+	_, err = w.Write(msg)
+	w.Close()
+	return err
+}
+
+func (handler *hybiFrameHandler) WritePong(msg []byte) (n int, err error) {
+	handler.conn.wio.Lock()
+	defer handler.conn.wio.Unlock()
+	w, err := handler.conn.frameWriterFactory.NewFrameWriter(PongFrame)
+	if err != nil {
+		return 0, err
+	}
+	n, err = w.Write(msg)
+	w.Close()
+	return n, err
+}
+
+// newHybiConn creates a new WebSocket connection speaking hybi draft protocol.
+func newHybiConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
+	if buf == nil {
+		br := bufio.NewReader(rwc)
+		bw := bufio.NewWriter(rwc)
+		buf = bufio.NewReadWriter(br, bw)
+	}
+	ws := &Conn{config: config, request: request, buf: buf, rwc: rwc,
+		frameReaderFactory: hybiFrameReaderFactory{buf.Reader},
+		frameWriterFactory: hybiFrameWriterFactory{
+			buf.Writer, request == nil},
+		PayloadType:        TextFrame,
+		defaultCloseStatus: closeStatusNormal}
+	ws.frameHandler = &hybiFrameHandler{conn: ws}
+	return ws
+}
+
+// generateMaskingKey generates a masking key for a frame.
+func generateMaskingKey() (maskingKey []byte, err error) {
+	maskingKey = make([]byte, 4)
+	if _, err = io.ReadFull(rand.Reader, maskingKey); err != nil {
+		return
+	}
+	return
+}
+
+// generateNonce generates a nonce consisting of a randomly selected 16-byte
+// value that has been base64-encoded.
+func generateNonce() (nonce []byte) {
+	key := make([]byte, 16)
+	if _, err := io.ReadFull(rand.Reader, key); err != nil {
+		panic(err)
+	}
+	nonce = make([]byte, 24)
+	base64.StdEncoding.Encode(nonce, key)
+	return
+}
+
+// removeZone removes IPv6 zone identifer from host.
+// E.g., "[fe80::1%en0]:8080" to "[fe80::1]:8080"
+func removeZone(host string) string {
+	if !strings.HasPrefix(host, "[") {
+		return host
+	}
+	i := strings.LastIndex(host, "]")
+	if i < 0 {
+		return host
+	}
+	j := strings.LastIndex(host[:i], "%")
+	if j < 0 {
+		return host
+	}
+	return host[:j] + host[i:]
+}
+
+// getNonceAccept computes the base64-encoded SHA-1 of the concatenation of
+// the nonce ("Sec-WebSocket-Key" value) with the websocket GUID string.
+func getNonceAccept(nonce []byte) (expected []byte, err error) {
+	h := sha1.New()
+	if _, err = h.Write(nonce); err != nil {
+		return
+	}
+	if _, err = h.Write([]byte(websocketGUID)); err != nil {
+		return
+	}
+	expected = make([]byte, 28)
+	base64.StdEncoding.Encode(expected, h.Sum(nil))
+	return
+}
+
+// Client handshake described in draft-ietf-hybi-thewebsocket-protocol-17
+func hybiClientHandshake(config *Config, br *bufio.Reader, bw *bufio.Writer) (err error) {
+	bw.WriteString("GET " + config.Location.RequestURI() + " HTTP/1.1\r\n")
+
+	// According to RFC 6874, an HTTP client, proxy, or other
+	// intermediary must remove any IPv6 zone identifier attached
+	// to an outgoing URI.
+	bw.WriteString("Host: " + removeZone(config.Location.Host) + "\r\n")
+	bw.WriteString("Upgrade: websocket\r\n")
+	bw.WriteString("Connection: Upgrade\r\n")
+	nonce := generateNonce()
+	if config.handshakeData != nil {
+		nonce = []byte(config.handshakeData["key"])
+	}
+	bw.WriteString("Sec-WebSocket-Key: " + string(nonce) + "\r\n")
+	bw.WriteString("Origin: " + strings.ToLower(config.Origin.String()) + "\r\n")
+
+	if config.Version != ProtocolVersionHybi13 {
+		return ErrBadProtocolVersion
+	}
+
+	bw.WriteString("Sec-WebSocket-Version: " + fmt.Sprintf("%d", config.Version) + "\r\n")
+	if len(config.Protocol) > 0 {
+		bw.WriteString("Sec-WebSocket-Protocol: " + strings.Join(config.Protocol, ", ") + "\r\n")
+	}
+	// TODO(ukai): send Sec-WebSocket-Extensions.
+	err = config.Header.WriteSubset(bw, handshakeHeader)
+	if err != nil {
+		return err
+	}
+
+	bw.WriteString("\r\n")
+	if err = bw.Flush(); err != nil {
+		return err
+	}
+
+	resp, err := http.ReadResponse(br, &http.Request{Method: "GET"})
+	if err != nil {
+		return err
+	}
+	if resp.StatusCode != 101 {
+		return ErrBadStatus
+	}
+	if strings.ToLower(resp.Header.Get("Upgrade")) != "websocket" ||
+		strings.ToLower(resp.Header.Get("Connection")) != "upgrade" {
+		return ErrBadUpgrade
+	}
+	expectedAccept, err := getNonceAccept(nonce)
+	if err != nil {
+		return err
+	}
+	if resp.Header.Get("Sec-WebSocket-Accept") != string(expectedAccept) {
+		return ErrChallengeResponse
+	}
+	if resp.Header.Get("Sec-WebSocket-Extensions") != "" {
+		return ErrUnsupportedExtensions
+	}
+	offeredProtocol := resp.Header.Get("Sec-WebSocket-Protocol")
+	if offeredProtocol != "" {
+		protocolMatched := false
+		for i := 0; i < len(config.Protocol); i++ {
+			if config.Protocol[i] == offeredProtocol {
+				protocolMatched = true
+				break
+			}
+		}
+		if !protocolMatched {
+			return ErrBadWebSocketProtocol
+		}
+		config.Protocol = []string{offeredProtocol}
+	}
+
+	return nil
+}
+
+// newHybiClientConn creates a client WebSocket connection after handshake.
+func newHybiClientConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser) *Conn {
+	return newHybiConn(config, buf, rwc, nil)
+}
+
+// A HybiServerHandshaker performs a server handshake using hybi draft protocol.
+type hybiServerHandshaker struct {
+	*Config
+	accept []byte
+}
+
+func (c *hybiServerHandshaker) ReadHandshake(buf *bufio.Reader, req *http.Request) (code int, err error) {
+	c.Version = ProtocolVersionHybi13
+	if req.Method != "GET" {
+		return http.StatusMethodNotAllowed, ErrBadRequestMethod
+	}
+	// HTTP version can be safely ignored.
+
+	if strings.ToLower(req.Header.Get("Upgrade")) != "websocket" ||
+		!strings.Contains(strings.ToLower(req.Header.Get("Connection")), "upgrade") {
+		return http.StatusBadRequest, ErrNotWebSocket
+	}
+
+	key := req.Header.Get("Sec-Websocket-Key")
+	if key == "" {
+		return http.StatusBadRequest, ErrChallengeResponse
+	}
+	version := req.Header.Get("Sec-Websocket-Version")
+	switch version {
+	case "13":
+		c.Version = ProtocolVersionHybi13
+	default:
+		return http.StatusBadRequest, ErrBadWebSocketVersion
+	}
+	var scheme string
+	if req.TLS != nil {
+		scheme = "wss"
+	} else {
+		scheme = "ws"
+	}
+	c.Location, err = url.ParseRequestURI(scheme + "://" + req.Host + req.URL.RequestURI())
+	if err != nil {
+		return http.StatusBadRequest, err
+	}
+	protocol := strings.TrimSpace(req.Header.Get("Sec-Websocket-Protocol"))
+	if protocol != "" {
+		protocols := strings.Split(protocol, ",")
+		for i := 0; i < len(protocols); i++ {
+			c.Protocol = append(c.Protocol, strings.TrimSpace(protocols[i]))
+		}
+	}
+	c.accept, err = getNonceAccept([]byte(key))
+	if err != nil {
+		return http.StatusInternalServerError, err
+	}
+	return http.StatusSwitchingProtocols, nil
+}
+
+// Origin parses the Origin header in req.
+// If the Origin header is not set, it returns nil and nil.
+func Origin(config *Config, req *http.Request) (*url.URL, error) {
+	var origin string
+	switch config.Version {
+	case ProtocolVersionHybi13:
+		origin = req.Header.Get("Origin")
+	}
+	if origin == "" {
+		return nil, nil
+	}
+	return url.ParseRequestURI(origin)
+}
+
+func (c *hybiServerHandshaker) AcceptHandshake(buf *bufio.Writer) (err error) {
+	if len(c.Protocol) > 0 {
+		if len(c.Protocol) != 1 {
+			// You need choose a Protocol in Handshake func in Server.
+			return ErrBadWebSocketProtocol
+		}
+	}
+	buf.WriteString("HTTP/1.1 101 Switching Protocols\r\n")
+	buf.WriteString("Upgrade: websocket\r\n")
+	buf.WriteString("Connection: Upgrade\r\n")
+	buf.WriteString("Sec-WebSocket-Accept: " + string(c.accept) + "\r\n")
+	if len(c.Protocol) > 0 {
+		buf.WriteString("Sec-WebSocket-Protocol: " + c.Protocol[0] + "\r\n")
+	}
+	// TODO(ukai): send Sec-WebSocket-Extensions.
+	if c.Header != nil {
+		err := c.Header.WriteSubset(buf, handshakeHeader)
+		if err != nil {
+			return err
+		}
+	}
+	buf.WriteString("\r\n")
+	return buf.Flush()
+}
+
+func (c *hybiServerHandshaker) NewServerConn(buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
+	return newHybiServerConn(c.Config, buf, rwc, request)
+}
+
+// newHybiServerConn returns a new WebSocket connection speaking hybi draft protocol.
+func newHybiServerConn(config *Config, buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) *Conn {
+	return newHybiConn(config, buf, rwc, request)
+}
diff --git a/vendor/golang.org/x/net/websocket/server.go b/vendor/golang.org/x/net/websocket/server.go
new file mode 100644
index 00000000..0895dea1
--- /dev/null
+++ b/vendor/golang.org/x/net/websocket/server.go
@@ -0,0 +1,113 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"net/http"
+)
+
+func newServerConn(rwc io.ReadWriteCloser, buf *bufio.ReadWriter, req *http.Request, config *Config, handshake func(*Config, *http.Request) error) (conn *Conn, err error) {
+	var hs serverHandshaker = &hybiServerHandshaker{Config: config}
+	code, err := hs.ReadHandshake(buf.Reader, req)
+	if err == ErrBadWebSocketVersion {
+		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
+		fmt.Fprintf(buf, "Sec-WebSocket-Version: %s\r\n", SupportedProtocolVersion)
+		buf.WriteString("\r\n")
+		buf.WriteString(err.Error())
+		buf.Flush()
+		return
+	}
+	if err != nil {
+		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
+		buf.WriteString("\r\n")
+		buf.WriteString(err.Error())
+		buf.Flush()
+		return
+	}
+	if handshake != nil {
+		err = handshake(config, req)
+		if err != nil {
+			code = http.StatusForbidden
+			fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
+			buf.WriteString("\r\n")
+			buf.Flush()
+			return
+		}
+	}
+	err = hs.AcceptHandshake(buf.Writer)
+	if err != nil {
+		code = http.StatusBadRequest
+		fmt.Fprintf(buf, "HTTP/1.1 %03d %s\r\n", code, http.StatusText(code))
+		buf.WriteString("\r\n")
+		buf.Flush()
+		return
+	}
+	conn = hs.NewServerConn(buf, rwc, req)
+	return
+}
+
+// Server represents a server of a WebSocket.
+type Server struct {
+	// Config is a WebSocket configuration for new WebSocket connection.
+	Config
+
+	// Handshake is an optional function in WebSocket handshake.
+	// For example, you can check, or don't check Origin header.
+	// Another example, you can select config.Protocol.
+	Handshake func(*Config, *http.Request) error
+
+	// Handler handles a WebSocket connection.
+	Handler
+}
+
+// ServeHTTP implements the http.Handler interface for a WebSocket
+func (s Server) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	s.serveWebSocket(w, req)
+}
+
+func (s Server) serveWebSocket(w http.ResponseWriter, req *http.Request) {
+	rwc, buf, err := w.(http.Hijacker).Hijack()
+	if err != nil {
+		panic("Hijack failed: " + err.Error())
+	}
+	// The server should abort the WebSocket connection if it finds
+	// the client did not send a handshake that matches with protocol
+	// specification.
+	defer rwc.Close()
+	conn, err := newServerConn(rwc, buf, req, &s.Config, s.Handshake)
+	if err != nil {
+		return
+	}
+	if conn == nil {
+		panic("unexpected nil conn")
+	}
+	s.Handler(conn)
+}
+
+// Handler is a simple interface to a WebSocket browser client.
+// It checks if Origin header is valid URL by default.
+// You might want to verify websocket.Conn.Config().Origin in the func.
+// If you use Server instead of Handler, you could call websocket.Origin and
+// check the origin in your Handshake func. So, if you want to accept
+// non-browser clients, which do not send an Origin header, set a
+// Server.Handshake that does not check the origin.
+type Handler func(*Conn)
+
+func checkOrigin(config *Config, req *http.Request) (err error) {
+	config.Origin, err = Origin(config, req)
+	if err == nil && config.Origin == nil {
+		return fmt.Errorf("null origin")
+	}
+	return err
+}
+
+// ServeHTTP implements the http.Handler interface for a WebSocket
+func (h Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	s := Server{Handler: h, Handshake: checkOrigin}
+	s.serveWebSocket(w, req)
+}
diff --git a/vendor/golang.org/x/net/websocket/websocket.go b/vendor/golang.org/x/net/websocket/websocket.go
new file mode 100644
index 00000000..e242c89a
--- /dev/null
+++ b/vendor/golang.org/x/net/websocket/websocket.go
@@ -0,0 +1,448 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package websocket implements a client and server for the WebSocket protocol
+// as specified in RFC 6455.
+//
+// This package currently lacks some features found in an alternative
+// and more actively maintained WebSocket package:
+//
+//     https://godoc.org/github.com/gorilla/websocket
+//
+package websocket // import "golang.org/x/net/websocket"
+
+import (
+	"bufio"
+	"crypto/tls"
+	"encoding/json"
+	"errors"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"sync"
+	"time"
+)
+
+const (
+	ProtocolVersionHybi13    = 13
+	ProtocolVersionHybi      = ProtocolVersionHybi13
+	SupportedProtocolVersion = "13"
+
+	ContinuationFrame = 0
+	TextFrame         = 1
+	BinaryFrame       = 2
+	CloseFrame        = 8
+	PingFrame         = 9
+	PongFrame         = 10
+	UnknownFrame      = 255
+
+	DefaultMaxPayloadBytes = 32 << 20 // 32MB
+)
+
+// ProtocolError represents WebSocket protocol errors.
+type ProtocolError struct {
+	ErrorString string
+}
+
+func (err *ProtocolError) Error() string { return err.ErrorString }
+
+var (
+	ErrBadProtocolVersion   = &ProtocolError{"bad protocol version"}
+	ErrBadScheme            = &ProtocolError{"bad scheme"}
+	ErrBadStatus            = &ProtocolError{"bad status"}
+	ErrBadUpgrade           = &ProtocolError{"missing or bad upgrade"}
+	ErrBadWebSocketOrigin   = &ProtocolError{"missing or bad WebSocket-Origin"}
+	ErrBadWebSocketLocation = &ProtocolError{"missing or bad WebSocket-Location"}
+	ErrBadWebSocketProtocol = &ProtocolError{"missing or bad WebSocket-Protocol"}
+	ErrBadWebSocketVersion  = &ProtocolError{"missing or bad WebSocket Version"}
+	ErrChallengeResponse    = &ProtocolError{"mismatch challenge/response"}
+	ErrBadFrame             = &ProtocolError{"bad frame"}
+	ErrBadFrameBoundary     = &ProtocolError{"not on frame boundary"}
+	ErrNotWebSocket         = &ProtocolError{"not websocket protocol"}
+	ErrBadRequestMethod     = &ProtocolError{"bad method"}
+	ErrNotSupported         = &ProtocolError{"not supported"}
+)
+
+// ErrFrameTooLarge is returned by Codec's Receive method if payload size
+// exceeds limit set by Conn.MaxPayloadBytes
+var ErrFrameTooLarge = errors.New("websocket: frame payload size exceeds limit")
+
+// Addr is an implementation of net.Addr for WebSocket.
+type Addr struct {
+	*url.URL
+}
+
+// Network returns the network type for a WebSocket, "websocket".
+func (addr *Addr) Network() string { return "websocket" }
+
+// Config is a WebSocket configuration
+type Config struct {
+	// A WebSocket server address.
+	Location *url.URL
+
+	// A Websocket client origin.
+	Origin *url.URL
+
+	// WebSocket subprotocols.
+	Protocol []string
+
+	// WebSocket protocol version.
+	Version int
+
+	// TLS config for secure WebSocket (wss).
+	TlsConfig *tls.Config
+
+	// Additional header fields to be sent in WebSocket opening handshake.
+	Header http.Header
+
+	// Dialer used when opening websocket connections.
+	Dialer *net.Dialer
+
+	handshakeData map[string]string
+}
+
+// serverHandshaker is an interface to handle WebSocket server side handshake.
+type serverHandshaker interface {
+	// ReadHandshake reads handshake request message from client.
+	// Returns http response code and error if any.
+	ReadHandshake(buf *bufio.Reader, req *http.Request) (code int, err error)
+
+	// AcceptHandshake accepts the client handshake request and sends
+	// handshake response back to client.
+	AcceptHandshake(buf *bufio.Writer) (err error)
+
+	// NewServerConn creates a new WebSocket connection.
+	NewServerConn(buf *bufio.ReadWriter, rwc io.ReadWriteCloser, request *http.Request) (conn *Conn)
+}
+
+// frameReader is an interface to read a WebSocket frame.
+type frameReader interface {
+	// Reader is to read payload of the frame.
+	io.Reader
+
+	// PayloadType returns payload type.
+	PayloadType() byte
+
+	// HeaderReader returns a reader to read header of the frame.
+	HeaderReader() io.Reader
+
+	// TrailerReader returns a reader to read trailer of the frame.
+	// If it returns nil, there is no trailer in the frame.
+	TrailerReader() io.Reader
+
+	// Len returns total length of the frame, including header and trailer.
+	Len() int
+}
+
+// frameReaderFactory is an interface to creates new frame reader.
+type frameReaderFactory interface {
+	NewFrameReader() (r frameReader, err error)
+}
+
+// frameWriter is an interface to write a WebSocket frame.
+type frameWriter interface {
+	// Writer is to write payload of the frame.
+	io.WriteCloser
+}
+
+// frameWriterFactory is an interface to create new frame writer.
+type frameWriterFactory interface {
+	NewFrameWriter(payloadType byte) (w frameWriter, err error)
+}
+
+type frameHandler interface {
+	HandleFrame(frame frameReader) (r frameReader, err error)
+	WriteClose(status int) (err error)
+}
+
+// Conn represents a WebSocket connection.
+//
+// Multiple goroutines may invoke methods on a Conn simultaneously.
+type Conn struct {
+	config  *Config
+	request *http.Request
+
+	buf *bufio.ReadWriter
+	rwc io.ReadWriteCloser
+
+	rio sync.Mutex
+	frameReaderFactory
+	frameReader
+
+	wio sync.Mutex
+	frameWriterFactory
+
+	frameHandler
+	PayloadType        byte
+	defaultCloseStatus int
+
+	// MaxPayloadBytes limits the size of frame payload received over Conn
+	// by Codec's Receive method. If zero, DefaultMaxPayloadBytes is used.
+	MaxPayloadBytes int
+}
+
+// Read implements the io.Reader interface:
+// it reads data of a frame from the WebSocket connection.
+// if msg is not large enough for the frame data, it fills the msg and next Read
+// will read the rest of the frame data.
+// it reads Text frame or Binary frame.
+func (ws *Conn) Read(msg []byte) (n int, err error) {
+	ws.rio.Lock()
+	defer ws.rio.Unlock()
+again:
+	if ws.frameReader == nil {
+		frame, err := ws.frameReaderFactory.NewFrameReader()
+		if err != nil {
+			return 0, err
+		}
+		ws.frameReader, err = ws.frameHandler.HandleFrame(frame)
+		if err != nil {
+			return 0, err
+		}
+		if ws.frameReader == nil {
+			goto again
+		}
+	}
+	n, err = ws.frameReader.Read(msg)
+	if err == io.EOF {
+		if trailer := ws.frameReader.TrailerReader(); trailer != nil {
+			io.Copy(ioutil.Discard, trailer)
+		}
+		ws.frameReader = nil
+		goto again
+	}
+	return n, err
+}
+
+// Write implements the io.Writer interface:
+// it writes data as a frame to the WebSocket connection.
+func (ws *Conn) Write(msg []byte) (n int, err error) {
+	ws.wio.Lock()
+	defer ws.wio.Unlock()
+	w, err := ws.frameWriterFactory.NewFrameWriter(ws.PayloadType)
+	if err != nil {
+		return 0, err
+	}
+	n, err = w.Write(msg)
+	w.Close()
+	return n, err
+}
+
+// Close implements the io.Closer interface.
+func (ws *Conn) Close() error {
+	err := ws.frameHandler.WriteClose(ws.defaultCloseStatus)
+	err1 := ws.rwc.Close()
+	if err != nil {
+		return err
+	}
+	return err1
+}
+
+func (ws *Conn) IsClientConn() bool { return ws.request == nil }
+func (ws *Conn) IsServerConn() bool { return ws.request != nil }
+
+// LocalAddr returns the WebSocket Origin for the connection for client, or
+// the WebSocket location for server.
+func (ws *Conn) LocalAddr() net.Addr {
+	if ws.IsClientConn() {
+		return &Addr{ws.config.Origin}
+	}
+	return &Addr{ws.config.Location}
+}
+
+// RemoteAddr returns the WebSocket location for the connection for client, or
+// the Websocket Origin for server.
+func (ws *Conn) RemoteAddr() net.Addr {
+	if ws.IsClientConn() {
+		return &Addr{ws.config.Location}
+	}
+	return &Addr{ws.config.Origin}
+}
+
+var errSetDeadline = errors.New("websocket: cannot set deadline: not using a net.Conn")
+
+// SetDeadline sets the connection's network read & write deadlines.
+func (ws *Conn) SetDeadline(t time.Time) error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetDeadline(t)
+	}
+	return errSetDeadline
+}
+
+// SetReadDeadline sets the connection's network read deadline.
+func (ws *Conn) SetReadDeadline(t time.Time) error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetReadDeadline(t)
+	}
+	return errSetDeadline
+}
+
+// SetWriteDeadline sets the connection's network write deadline.
+func (ws *Conn) SetWriteDeadline(t time.Time) error {
+	if conn, ok := ws.rwc.(net.Conn); ok {
+		return conn.SetWriteDeadline(t)
+	}
+	return errSetDeadline
+}
+
+// Config returns the WebSocket config.
+func (ws *Conn) Config() *Config { return ws.config }
+
+// Request returns the http request upgraded to the WebSocket.
+// It is nil for client side.
+func (ws *Conn) Request() *http.Request { return ws.request }
+
+// Codec represents a symmetric pair of functions that implement a codec.
+type Codec struct {
+	Marshal   func(v interface{}) (data []byte, payloadType byte, err error)
+	Unmarshal func(data []byte, payloadType byte, v interface{}) (err error)
+}
+
+// Send sends v marshaled by cd.Marshal as single frame to ws.
+func (cd Codec) Send(ws *Conn, v interface{}) (err error) {
+	data, payloadType, err := cd.Marshal(v)
+	if err != nil {
+		return err
+	}
+	ws.wio.Lock()
+	defer ws.wio.Unlock()
+	w, err := ws.frameWriterFactory.NewFrameWriter(payloadType)
+	if err != nil {
+		return err
+	}
+	_, err = w.Write(data)
+	w.Close()
+	return err
+}
+
+// Receive receives single frame from ws, unmarshaled by cd.Unmarshal and stores
+// in v. The whole frame payload is read to an in-memory buffer; max size of
+// payload is defined by ws.MaxPayloadBytes. If frame payload size exceeds
+// limit, ErrFrameTooLarge is returned; in this case frame is not read off wire
+// completely. The next call to Receive would read and discard leftover data of
+// previous oversized frame before processing next frame.
+func (cd Codec) Receive(ws *Conn, v interface{}) (err error) {
+	ws.rio.Lock()
+	defer ws.rio.Unlock()
+	if ws.frameReader != nil {
+		_, err = io.Copy(ioutil.Discard, ws.frameReader)
+		if err != nil {
+			return err
+		}
+		ws.frameReader = nil
+	}
+again:
+	frame, err := ws.frameReaderFactory.NewFrameReader()
+	if err != nil {
+		return err
+	}
+	frame, err = ws.frameHandler.HandleFrame(frame)
+	if err != nil {
+		return err
+	}
+	if frame == nil {
+		goto again
+	}
+	maxPayloadBytes := ws.MaxPayloadBytes
+	if maxPayloadBytes == 0 {
+		maxPayloadBytes = DefaultMaxPayloadBytes
+	}
+	if hf, ok := frame.(*hybiFrameReader); ok && hf.header.Length > int64(maxPayloadBytes) {
+		// payload size exceeds limit, no need to call Unmarshal
+		//
+		// set frameReader to current oversized frame so that
+		// the next call to this function can drain leftover
+		// data before processing the next frame
+		ws.frameReader = frame
+		return ErrFrameTooLarge
+	}
+	payloadType := frame.PayloadType()
+	data, err := ioutil.ReadAll(frame)
+	if err != nil {
+		return err
+	}
+	return cd.Unmarshal(data, payloadType, v)
+}
+
+func marshal(v interface{}) (msg []byte, payloadType byte, err error) {
+	switch data := v.(type) {
+	case string:
+		return []byte(data), TextFrame, nil
+	case []byte:
+		return data, BinaryFrame, nil
+	}
+	return nil, UnknownFrame, ErrNotSupported
+}
+
+func unmarshal(msg []byte, payloadType byte, v interface{}) (err error) {
+	switch data := v.(type) {
+	case *string:
+		*data = string(msg)
+		return nil
+	case *[]byte:
+		*data = msg
+		return nil
+	}
+	return ErrNotSupported
+}
+
+/*
+Message is a codec to send/receive text/binary data in a frame on WebSocket connection.
+To send/receive text frame, use string type.
+To send/receive binary frame, use []byte type.
+
+Trivial usage:
+
+	import "websocket"
+
+	// receive text frame
+	var message string
+	websocket.Message.Receive(ws, &message)
+
+	// send text frame
+	message = "hello"
+	websocket.Message.Send(ws, message)
+
+	// receive binary frame
+	var data []byte
+	websocket.Message.Receive(ws, &data)
+
+	// send binary frame
+	data = []byte{0, 1, 2}
+	websocket.Message.Send(ws, data)
+
+*/
+var Message = Codec{marshal, unmarshal}
+
+func jsonMarshal(v interface{}) (msg []byte, payloadType byte, err error) {
+	msg, err = json.Marshal(v)
+	return msg, TextFrame, err
+}
+
+func jsonUnmarshal(msg []byte, payloadType byte, v interface{}) (err error) {
+	return json.Unmarshal(msg, v)
+}
+
+/*
+JSON is a codec to send/receive JSON data in a frame from a WebSocket connection.
+
+Trivial usage:
+
+	import "websocket"
+
+	type T struct {
+		Msg string
+		Count int
+	}
+
+	// receive JSON type T
+	var data T
+	websocket.JSON.Receive(ws, &data)
+
+	// send JSON type T
+	websocket.JSON.Send(ws, data)
+*/
+var JSON = Codec{jsonMarshal, jsonUnmarshal}