1 files changed, 522 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/ldap/conn.go b/vendor/github.com/mattermost/ldap/conn.go
new file mode 100644
index 00000000..5b7ac478
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/conn.go
@@ -0,0 +1,522 @@
+package ldap
+
+import (
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"net/url"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+const (
+	// MessageQuit causes the processMessages loop to exit
+	MessageQuit = 0
+	// MessageRequest sends a request to the server
+	MessageRequest = 1
+	// MessageResponse receives a response from the server
+	MessageResponse = 2
+	// MessageFinish indicates the client considers a particular message ID to be finished
+	MessageFinish = 3
+	// MessageTimeout indicates the client-specified timeout for a particular message ID has been reached
+	MessageTimeout = 4
+)
+
+const (
+	// DefaultLdapPort default ldap port for pure TCP connection
+	DefaultLdapPort = "389"
+	// DefaultLdapsPort default ldap port for SSL connection
+	DefaultLdapsPort = "636"
+)
+
+// PacketResponse contains the packet or error encountered reading a response
+type PacketResponse struct {
+	// Packet is the packet read from the server
+	Packet *ber.Packet
+	// Error is an error encountered while reading
+	Error error
+}
+
+// ReadPacket returns the packet or an error
+func (pr *PacketResponse) ReadPacket() (*ber.Packet, error) {
+	if (pr == nil) || (pr.Packet == nil && pr.Error == nil) {
+		return nil, NewError(ErrorNetwork, errors.New("ldap: could not retrieve response"))
+	}
+	return pr.Packet, pr.Error
+}
+
+type messageContext struct {
+	id int64
+	// close(done) should only be called from finishMessage()
+	done chan struct{}
+	// close(responses) should only be called from processMessages(), and only sent to from sendResponse()
+	responses chan *PacketResponse
+}
+
+// sendResponse should only be called within the processMessages() loop which
+// is also responsible for closing the responses channel.
+func (msgCtx *messageContext) sendResponse(packet *PacketResponse) {
+	select {
+	case msgCtx.responses <- packet:
+		// Successfully sent packet to message handler.
+	case <-msgCtx.done:
+		// The request handler is done and will not receive more
+		// packets.
+	}
+}
+
+type messagePacket struct {
+	Op        int
+	MessageID int64
+	Packet    *ber.Packet
+	Context   *messageContext
+}
+
+type sendMessageFlags uint
+
+const (
+	startTLS sendMessageFlags = 1 << iota
+)
+
+// Conn represents an LDAP Connection
+type Conn struct {
+	// requestTimeout is loaded atomically
+	// so we need to ensure 64-bit alignment on 32-bit platforms.
+	requestTimeout      int64
+	conn                net.Conn
+	isTLS               bool
+	closing             uint32
+	closeErr            atomic.Value
+	isStartingTLS       bool
+	Debug               debugging
+	chanConfirm         chan struct{}
+	messageContexts     map[int64]*messageContext
+	chanMessage         chan *messagePacket
+	chanMessageID       chan int64
+	wgClose             sync.WaitGroup
+	outstandingRequests uint
+	messageMutex        sync.Mutex
+}
+
+var _ Client = &Conn{}
+
+// DefaultTimeout is a package-level variable that sets the timeout value
+// used for the Dial and DialTLS methods.
+//
+// WARNING: since this is a package-level variable, setting this value from
+// multiple places will probably result in undesired behaviour.
+var DefaultTimeout = 60 * time.Second
+
+// Dial connects to the given address on the given network using net.Dial
+// and then returns a new Conn for the connection.
+func Dial(network, addr string) (*Conn, error) {
+	c, err := net.DialTimeout(network, addr, DefaultTimeout)
+	if err != nil {
+		return nil, NewError(ErrorNetwork, err)
+	}
+	conn := NewConn(c, false)
+	conn.Start()
+	return conn, nil
+}
+
+// DialTLS connects to the given address on the given network using tls.Dial
+// and then returns a new Conn for the connection.
+func DialTLS(network, addr string, config *tls.Config) (*Conn, error) {
+	c, err := tls.DialWithDialer(&net.Dialer{Timeout: DefaultTimeout}, network, addr, config)
+	if err != nil {
+		return nil, NewError(ErrorNetwork, err)
+	}
+	conn := NewConn(c, true)
+	conn.Start()
+	return conn, nil
+}
+
+// DialURL connects to the given ldap URL vie TCP using tls.Dial or net.Dial if ldaps://
+// or ldap:// specified as protocol. On success a new Conn for the connection
+// is returned.
+func DialURL(addr string) (*Conn, error) {
+	lurl, err := url.Parse(addr)
+	if err != nil {
+		return nil, NewError(ErrorNetwork, err)
+	}
+
+	host, port, err := net.SplitHostPort(lurl.Host)
+	if err != nil {
+		// we asume that error is due to missing port
+		host = lurl.Host
+		port = ""
+	}
+
+	switch lurl.Scheme {
+	case "ldapi":
+		if lurl.Path == "" || lurl.Path == "/" {
+			lurl.Path = "/var/run/slapd/ldapi"
+		}
+		return Dial("unix", lurl.Path)
+	case "ldap":
+		if port == "" {
+			port = DefaultLdapPort
+		}
+		return Dial("tcp", net.JoinHostPort(host, port))
+	case "ldaps":
+		if port == "" {
+			port = DefaultLdapsPort
+		}
+		tlsConf := &tls.Config{
+			ServerName: host,
+		}
+		return DialTLS("tcp", net.JoinHostPort(host, port), tlsConf)
+	}
+
+	return nil, NewError(ErrorNetwork, fmt.Errorf("Unknown scheme '%s'", lurl.Scheme))
+}
+
+// NewConn returns a new Conn using conn for network I/O.
+func NewConn(conn net.Conn, isTLS bool) *Conn {
+	return &Conn{
+		conn:            conn,
+		chanConfirm:     make(chan struct{}),
+		chanMessageID:   make(chan int64),
+		chanMessage:     make(chan *messagePacket, 10),
+		messageContexts: map[int64]*messageContext{},
+		requestTimeout:  0,
+		isTLS:           isTLS,
+	}
+}
+
+// Start initializes goroutines to read responses and process messages
+func (l *Conn) Start() {
+	l.wgClose.Add(1)
+	go l.reader()
+	go l.processMessages()
+}
+
+// IsClosing returns whether or not we're currently closing.
+func (l *Conn) IsClosing() bool {
+	return atomic.LoadUint32(&l.closing) == 1
+}
+
+// setClosing sets the closing value to true
+func (l *Conn) setClosing() bool {
+	return atomic.CompareAndSwapUint32(&l.closing, 0, 1)
+}
+
+// Close closes the connection.
+func (l *Conn) Close() {
+	l.messageMutex.Lock()
+	defer l.messageMutex.Unlock()
+
+	if l.setClosing() {
+		l.Debug.Printf("Sending quit message and waiting for confirmation")
+		l.chanMessage <- &messagePacket{Op: MessageQuit}
+		<-l.chanConfirm
+		close(l.chanMessage)
+
+		l.Debug.Printf("Closing network connection")
+		if err := l.conn.Close(); err != nil {
+			log.Println(err)
+		}
+
+		l.wgClose.Done()
+	}
+	l.wgClose.Wait()
+}
+
+// SetTimeout sets the time after a request is sent that a MessageTimeout triggers
+func (l *Conn) SetTimeout(timeout time.Duration) {
+	if timeout > 0 {
+		atomic.StoreInt64(&l.requestTimeout, int64(timeout))
+	}
+}
+
+// Returns the next available messageID
+func (l *Conn) nextMessageID() int64 {
+	if messageID, ok := <-l.chanMessageID; ok {
+		return messageID
+	}
+	return 0
+}
+
+// StartTLS sends the command to start a TLS session and then creates a new TLS Client
+func (l *Conn) StartTLS(config *tls.Config) error {
+	if l.isTLS {
+		return NewError(ErrorNetwork, errors.New("ldap: already encrypted"))
+	}
+
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "LDAP Request")
+	packet.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, l.nextMessageID(), "MessageID"))
+	request := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationExtendedRequest, nil, "Start TLS")
+	request.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, 0, "1.3.6.1.4.1.1466.20037", "TLS Extended Command"))
+	packet.AppendChild(request)
+	l.Debug.PrintPacket(packet)
+
+	msgCtx, err := l.sendMessageWithFlags(packet, startTLS)
+	if err != nil {
+		return err
+	}
+	defer l.finishMessage(msgCtx)
+
+	l.Debug.Printf("%d: waiting for response", msgCtx.id)
+
+	packetResponse, ok := <-msgCtx.responses
+	if !ok {
+		return NewError(ErrorNetwork, errors.New("ldap: response channel closed"))
+	}
+	packet, err = packetResponse.ReadPacket()
+	l.Debug.Printf("%d: got response %p", msgCtx.id, packet)
+	if err != nil {
+		return err
+	}
+
+	if l.Debug {
+		if err := addLDAPDescriptions(packet); err != nil {
+			l.Close()
+			return err
+		}
+		l.Debug.PrintPacket(packet)
+	}
+
+	if err := GetLDAPError(packet); err == nil {
+		conn := tls.Client(l.conn, config)
+
+		if connErr := conn.Handshake(); connErr != nil {
+			l.Close()
+			return NewError(ErrorNetwork, fmt.Errorf("TLS handshake failed (%v)", connErr))
+		}
+
+		l.isTLS = true
+		l.conn = conn
+	} else {
+		return err
+	}
+	go l.reader()
+
+	return nil
+}
+
+// TLSConnectionState returns the client's TLS connection state.
+// The return values are their zero values if StartTLS did
+// not succeed.
+func (l *Conn) TLSConnectionState() (state tls.ConnectionState, ok bool) {
+	tc, ok := l.conn.(*tls.Conn)
+	if !ok {
+		return
+	}
+	return tc.ConnectionState(), true
+}
+
+func (l *Conn) sendMessage(packet *ber.Packet) (*messageContext, error) {
+	return l.sendMessageWithFlags(packet, 0)
+}
+
+func (l *Conn) sendMessageWithFlags(packet *ber.Packet, flags sendMessageFlags) (*messageContext, error) {
+	if l.IsClosing() {
+		return nil, NewError(ErrorNetwork, errors.New("ldap: connection closed"))
+	}
+	l.messageMutex.Lock()
+	l.Debug.Printf("flags&startTLS = %d", flags&startTLS)
+	if l.isStartingTLS {
+		l.messageMutex.Unlock()
+		return nil, NewError(ErrorNetwork, errors.New("ldap: connection is in startls phase"))
+	}
+	if flags&startTLS != 0 {
+		if l.outstandingRequests != 0 {
+			l.messageMutex.Unlock()
+			return nil, NewError(ErrorNetwork, errors.New("ldap: cannot StartTLS with outstanding requests"))
+		}
+		l.isStartingTLS = true
+	}
+	l.outstandingRequests++
+
+	l.messageMutex.Unlock()
+
+	responses := make(chan *PacketResponse)
+	messageID := packet.Children[0].Value.(int64)
+	message := &messagePacket{
+		Op:        MessageRequest,
+		MessageID: messageID,
+		Packet:    packet,
+		Context: &messageContext{
+			id:        messageID,
+			done:      make(chan struct{}),
+			responses: responses,
+		},
+	}
+	l.sendProcessMessage(message)
+	return message.Context, nil
+}
+
+func (l *Conn) finishMessage(msgCtx *messageContext) {
+	close(msgCtx.done)
+
+	if l.IsClosing() {
+		return
+	}
+
+	l.messageMutex.Lock()
+	l.outstandingRequests--
+	if l.isStartingTLS {
+		l.isStartingTLS = false
+	}
+	l.messageMutex.Unlock()
+
+	message := &messagePacket{
+		Op:        MessageFinish,
+		MessageID: msgCtx.id,
+	}
+	l.sendProcessMessage(message)
+}
+
+func (l *Conn) sendProcessMessage(message *messagePacket) bool {
+	l.messageMutex.Lock()
+	defer l.messageMutex.Unlock()
+	if l.IsClosing() {
+		return false
+	}
+	l.chanMessage <- message
+	return true
+}
+
+func (l *Conn) processMessages() {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Printf("ldap: recovered panic in processMessages: %v", err)
+		}
+		for messageID, msgCtx := range l.messageContexts {
+			// If we are closing due to an error, inform anyone who
+			// is waiting about the error.
+			if l.IsClosing() && l.closeErr.Load() != nil {
+				msgCtx.sendResponse(&PacketResponse{Error: l.closeErr.Load().(error)})
+			}
+			l.Debug.Printf("Closing channel for MessageID %d", messageID)
+			close(msgCtx.responses)
+			delete(l.messageContexts, messageID)
+		}
+		close(l.chanMessageID)
+		close(l.chanConfirm)
+	}()
+
+	var messageID int64 = 1
+	for {
+		select {
+		case l.chanMessageID <- messageID:
+			messageID++
+		case message := <-l.chanMessage:
+			switch message.Op {
+			case MessageQuit:
+				l.Debug.Printf("Shutting down - quit message received")
+				return
+			case MessageRequest:
+				// Add to message list and write to network
+				l.Debug.Printf("Sending message %d", message.MessageID)
+
+				buf := message.Packet.Bytes()
+				_, err := l.conn.Write(buf)
+				if err != nil {
+					l.Debug.Printf("Error Sending Message: %s", err.Error())
+					message.Context.sendResponse(&PacketResponse{Error: fmt.Errorf("unable to send request: %s", err)})
+					close(message.Context.responses)
+					break
+				}
+
+				// Only add to messageContexts if we were able to
+				// successfully write the message.
+				l.messageContexts[message.MessageID] = message.Context
+
+				// Add timeout if defined
+				requestTimeout := time.Duration(atomic.LoadInt64(&l.requestTimeout))
+				if requestTimeout > 0 {
+					go func() {
+						defer func() {
+							if err := recover(); err != nil {
+								log.Printf("ldap: recovered panic in RequestTimeout: %v", err)
+							}
+						}()
+						time.Sleep(requestTimeout)
+						timeoutMessage := &messagePacket{
+							Op:        MessageTimeout,
+							MessageID: message.MessageID,
+						}
+						l.sendProcessMessage(timeoutMessage)
+					}()
+				}
+			case MessageResponse:
+				l.Debug.Printf("Receiving message %d", message.MessageID)
+				if msgCtx, ok := l.messageContexts[message.MessageID]; ok {
+					msgCtx.sendResponse(&PacketResponse{message.Packet, nil})
+				} else {
+					log.Printf("Received unexpected message %d, %v", message.MessageID, l.IsClosing())
+					l.Debug.PrintPacket(message.Packet)
+				}
+			case MessageTimeout:
+				// Handle the timeout by closing the channel
+				// All reads will return immediately
+				if msgCtx, ok := l.messageContexts[message.MessageID]; ok {
+					l.Debug.Printf("Receiving message timeout for %d", message.MessageID)
+					msgCtx.sendResponse(&PacketResponse{message.Packet, errors.New("ldap: connection timed out")})
+					delete(l.messageContexts, message.MessageID)
+					close(msgCtx.responses)
+				}
+			case MessageFinish:
+				l.Debug.Printf("Finished message %d", message.MessageID)
+				if msgCtx, ok := l.messageContexts[message.MessageID]; ok {
+					delete(l.messageContexts, message.MessageID)
+					close(msgCtx.responses)
+				}
+			}
+		}
+	}
+}
+
+func (l *Conn) reader() {
+	cleanstop := false
+	defer func() {
+		if err := recover(); err != nil {
+			log.Printf("ldap: recovered panic in reader: %v", err)
+		}
+		if !cleanstop {
+			l.Close()
+		}
+	}()
+
+	for {
+		if cleanstop {
+			l.Debug.Printf("reader clean stopping (without closing the connection)")
+			return
+		}
+		packet, err := ber.ReadPacket(l.conn)
+		if err != nil {
+			// A read error is expected here if we are closing the connection...
+			if !l.IsClosing() {
+				l.closeErr.Store(fmt.Errorf("unable to read LDAP response packet: %s", err))
+				l.Debug.Printf("reader error: %s", err)
+			}
+			return
+		}
+		if err := addLDAPDescriptions(packet); err != nil {
+			l.Debug.Printf("descriptions error: %s", err)
+		}
+		if len(packet.Children) == 0 {
+			l.Debug.Printf("Received bad ldap packet")
+			continue
+		}
+		l.messageMutex.Lock()
+		if l.isStartingTLS {
+			cleanstop = true
+		}
+		l.messageMutex.Unlock()
+		message := &messagePacket{
+			Op:        MessageResponse,
+			MessageID: packet.Children[0].Value.(int64),
+			Packet:    packet,
+		}
+		if !l.sendProcessMessage(message) {
+			return
+		}
+	}
+}