diff options
Diffstat (limited to 'vendor/golang.org/x/net/websocket/hybi.go')
| -rw-r--r-- | vendor/golang.org/x/net/websocket/hybi.go | 583 |
1 files changed, 583 insertions, 0 deletions
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 000000000..8cffdd16c --- /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) +} |