Initial working version of go XMPP library

xmpp/auth.go

@@ -0,0 +1,79 @@
+package xmpp
+
+import (
+	"encoding/base64"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"io"
+)
+
+func authSASL(socket io.ReadWriter, decoder *xml.Decoder, f streamFeatures, user string, password string) (err error) {
+	// TODO: Implement other type of SASL Authentication
+	havePlain := false
+	for _, m := range f.Mechanisms.Mechanism {
+		if m == "PLAIN" {
+			havePlain = true
+			break
+		}
+	}
+	if !havePlain {
+		return errors.New(fmt.Sprintf("PLAIN authentication is not supported by server: %v", f.Mechanisms.Mechanism))
+	}
+
+	return authPlain(socket, decoder, user, password)
+}
+
+// Plain authentication: send base64-encoded \x00 user \x00 password
+func authPlain(socket io.ReadWriter, decoder *xml.Decoder, user string, password string) error {
+	raw := "\x00" + user + "\x00" + password
+	enc := make([]byte, base64.StdEncoding.EncodedLen(len(raw)))
+	base64.StdEncoding.Encode(enc, []byte(raw))
+	fmt.Fprintf(socket, "<auth xmlns='%s' mechanism='PLAIN'>%s</auth>", nsSASL, enc)
+
+	// Next message should be either success or failure.
+	name, val, err := next(decoder)
+	if err != nil {
+		return err
+	}
+
+	switch v := val.(type) {
+	case *saslSuccess:
+	case *saslFailure:
+		// v.Any is type of sub-element in failure, which gives a description of what failed.
+		return errors.New("auth failure: " + v.Any.Local)
+	default:
+		return errors.New("expected success or failure, got " + name.Local + " in " + name.Space)
+	}
+	return err
+}
+
+// XMPP Packet Parsing
+type saslMechanisms struct {
+	XMLName   xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-sasl mechanisms"`
+	Mechanism []string `xml:"mechanism"`
+}
+
+type saslSuccess struct {
+	XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-sasl success"`
+}
+
+type saslFailure struct {
+	XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-sasl failure"`
+	Any     xml.Name // error reason is a subelement
+
+}
+
+type bindBind struct {
+	XMLName  xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-bind bind"`
+	Resource string
+	Jid      string
+}
+
+// Session is obsolete in RFC 6121.
+// Added for compliance with RFC 3121.
+// Remove when ejabberd purely conforms to RFC 6121.
+type sessionSession struct {
+	XMLName  xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-session session"`
+	optional xml.Name // If it does exist, it mean we are not required to open session
+}

xmpp/client.go

@@ -0,0 +1,116 @@
+package xmpp
+
+import (
+	"bytes"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"net"
+	"strings"
+)
+
+type Client struct {
+	// Store user defined options
+	options Options
+	// Session gather data that can be accessed by users of this library
+	Session *Session
+	// TCP level connection / can be replace by a TLS session after starttls
+	conn net.Conn
+}
+
+/*
+Setting up the client / Checking the parameters
+*/
+
+// TODO: better options check
+func NewClient(options Options) (c *Client, err error) {
+	// TODO: If option address is nil, use the Jid domain to compose the address
+	if options.Address, err = checkAddress(options.Address); err != nil {
+		return
+	}
+
+	if options.Password == "" {
+		err = errors.New("missing password")
+		return
+	}
+
+	c = new(Client)
+	c.options = options
+
+	// Parse JID
+	if c.options.parsedJid, err = NewJid(c.options.Jid); err != nil {
+		return
+	}
+
+	return
+}
+
+func checkAddress(addr string) (string, error) {
+	var err error
+	hostport := strings.Split(addr, ":")
+	if len(hostport) > 2 {
+		err = errors.New("too many colons in xmpp server address")
+		return addr, err
+	}
+
+	// Address is composed of two parts, we are good
+	if len(hostport) == 2 && hostport[1] != "" {
+		return addr, err
+	}
+
+	// Port was not passed, we append XMPP default port:
+	return strings.Join([]string{hostport[0], "5222"}, ":"), err
+}
+
+// NewClient creates a new connection to a host given as "hostname" or "hostname:port".
+// If host is not specified, the  DNS SRV should be used to find the host from the domainpart of the JID.
+// Default the port to 5222.
+func (c *Client) Connect() (*Session, error) {
+	var tcpconn net.Conn
+	var err error
+	if tcpconn, err = net.Dial("tcp", c.options.Address); err != nil {
+		return nil, err
+	}
+
+	c.conn = tcpconn
+	if c.conn, c.Session, err = NewSession(c.conn, c.options); err != nil {
+		return c.Session, err
+	}
+
+	// We're connected and can now receive and send messages.
+	//fmt.Fprintf(client.conn, "<presence xml:lang='en'><show>%s</show><status>%s</status></presence>", "chat", "Online")
+	fmt.Fprintf(c.Session.socketProxy, "<presence/>")
+
+	return c.Session, err
+}
+
+func (c *Client) recv(receiver chan<- interface{}) (err error) {
+	for {
+		_, val, err := next(c.Session.decoder)
+		if err != nil {
+			return err
+		}
+		receiver <- val
+		val = nil
+	}
+	panic("unreachable")
+}
+
+// Channel allow client to receive / dispatch packets in for range loop
+func (c *Client) Recv() <-chan interface{} {
+	ch := make(chan interface{})
+	go c.recv(ch)
+	return ch
+}
+
+// Send sends message text.
+func (c *Client) Send(packet string) error {
+	fmt.Fprintf(c.Session.socketProxy, packet)
+	return nil
+}
+
+func xmlEscape(s string) string {
+	var b bytes.Buffer
+	xml.Escape(&b, []byte(s))
+	return b.String()
+}

xmpp/iq.go

@@ -0,0 +1,11 @@
+package xmpp
+
+import "encoding/xml"
+
+type clientIQ struct { // info/query
+	XMLName xml.Name `xml:"jabber:client iq"`
+	Packet
+	Bind bindBind
+	// TODO We need to support detecting the IQ namespace / Query packet
+	// 	Error   clientError
+}

xmpp/jid.go

@@ -0,0 +1,34 @@
+package xmpp
+
+import (
+	"errors"
+	"strings"
+)
+
+type Jid struct {
+	username string
+	domain   string
+	resource string
+}
+
+func NewJid(sjid string) (jid *Jid, err error) {
+	s1 := strings.Split(sjid, "@")
+	if len(s1) != 2 {
+		err = errors.New("invalid JID: " + sjid)
+		return
+	}
+	jid = new(Jid)
+	jid.username = s1[0]
+
+	s2 := strings.Split(s1[1], "/")
+	if len(s2) > 2 {
+		err = errors.New("invalid JID: " + sjid)
+		return
+	}
+	jid.domain = s2[0]
+	if len(s2) == 2 {
+		jid.resource = s2[1]
+	}
+
+	return
+}

xmpp/message.go

@@ -0,0 +1,24 @@
+package xmpp
+
+import (
+	"encoding/xml"
+	"fmt"
+)
+
+// XMPP Packet Parsing
+type ClientMessage struct {
+	XMLName xml.Name `xml:"jabber:client message"`
+	Packet
+	Subject string `xml:"subject,omitempty"`
+	Body    string `xml:"body,omitempty"`
+	Thread  string `xml:"thread,omitempty"`
+}
+
+// TODO: Func new message to create an empty message structure without the XML tag matching elements
+
+func (message *ClientMessage) XMPPFormat() string {
+	return fmt.Sprintf("<message to='%s' type='chat' xml:lang='en'>"+
+		"<body>%s</body></message>",
+		message.To,
+		xmlEscape(message.Body))
+}

xmpp/ns.go

@@ -0,0 +1,10 @@
+package xmpp
+
+const (
+	nsStream  = "http://etherx.jabber.org/streams"
+	nsTLS     = "urn:ietf:params:xml:ns:xmpp-tls"
+	nsSASL    = "urn:ietf:params:xml:ns:xmpp-sasl"
+	nsBind    = "urn:ietf:params:xml:ns:xmpp-bind"
+	nsSession = "urn:ietf:params:xml:ns:xmpp-session"
+	nsClient  = "jabber:client"
+)

xmpp/options.go

@@ -0,0 +1,12 @@
+package xmpp
+
+import "os"
+
+type Options struct {
+	Address      string
+	Jid          string
+	parsedJid    *Jid // For easier manipulation
+	Password     string
+	PacketLogger *os.File // Used for debugging
+	Lang         string   // TODO: should default to 'en'
+}

xmpp/packet.go

@@ -0,0 +1,13 @@
+package xmpp
+
+type Packet struct {
+	Id   string `xml:"id,attr,omitempty"`
+	From string `xml:"from,attr,omitempty"`
+	To   string `xml:"to,attr,omitempty"`
+	Type string `xml:"type,attr,omitempty"`
+	Lang string `xml:"lang,attr,omitempty"`
+}
+
+type packetFormatter interface {
+	XMPPFormat() string
+}

xmpp/parser.go

@@ -0,0 +1,96 @@
+package xmpp
+
+import (
+	"encoding/xml"
+	"errors"
+	"io"
+	"log"
+)
+
+// Reads and checks the opening XMPP stream element.
+// It returns a stream structure containing:
+// - Host: You can check the host against the host you were expecting to connect to
+// - Id: the Stream ID is a temporary shared secret used for some hash calculation. It is also used by ProcessOne
+//       reattach features (allowing to resume an existing stream at the point the connection was interrupted, without
+//       getting through the authentication process.
+func initDecoder(p *xml.Decoder) (sessionID string, err error) {
+	for {
+		var t xml.Token
+		t, err = p.Token()
+		if err != nil {
+			return
+		}
+
+		switch elem := t.(type) {
+		case xml.StartElement:
+			if elem.Name.Space != nsStream || elem.Name.Local != "stream" {
+				err = errors.New("xmpp: expected <stream> but got <" + elem.Name.Local + "> in " + elem.Name.Space)
+				return
+			}
+
+			// Parse Stream attributes
+			for _, attrs := range elem.Attr {
+				switch attrs.Name.Local {
+				case "id":
+					sessionID = attrs.Value
+				}
+			}
+			return
+		}
+	}
+	panic("unreachable")
+}
+
+// Scan XML token stream to find next StartElement.
+func nextStart(p *xml.Decoder) (xml.StartElement, error) {
+	for {
+		t, err := p.Token()
+		if err == io.EOF {
+			return xml.StartElement{}, nil
+		}
+		if err != nil {
+			log.Fatal("token:", err)
+		}
+		switch t := t.(type) {
+		case xml.StartElement:
+			return t, nil
+		}
+	}
+	panic("unreachable")
+}
+
+// Scan XML token stream for next element and save into val.
+// If val == nil, allocate new element based on proto map.
+// Either way, return val.
+func next(p *xml.Decoder) (xml.Name, interface{}, error) {
+	// Read start element to find out what type we want.
+	se, err := nextStart(p)
+	if err != nil {
+		return xml.Name{}, nil, err
+	}
+
+	// Put it in an interface and allocate one.
+	var nv interface{}
+	switch se.Name.Space + " " + se.Name.Local {
+	// TODO: general case = Parse IQ / presence / message => split SASL case
+	case nsSASL + " success":
+		nv = &saslSuccess{}
+	case nsSASL + " failure":
+		nv = &saslFailure{}
+	case nsClient + " message":
+		nv = &ClientMessage{}
+	case nsClient + " presence":
+		nv = &clientPresence{}
+	case nsClient + " iq":
+		nv = &clientIQ{}
+	default:
+		return xml.Name{}, nil, errors.New("unexpected XMPP message " +
+			se.Name.Space + " <" + se.Name.Local + "/>")
+	}
+
+	// Decode element into pointer storage
+	if err = p.DecodeElement(nv, &se); err != nil {
+		return xml.Name{}, nil, err
+	}
+	return se.Name, nv, err
+}

xmpp/presence.go

@@ -0,0 +1,13 @@
+package xmpp
+
+import "encoding/xml"
+
+// XMPP Packet Parsing
+type clientPresence struct {
+	XMLName xml.Name `xml:"jabber:client presence"`
+	Packet
+	Show     string `xml:"show,attr,omitempty"` // away, chat, dnd, xa
+	Status   string `xml:"status,attr,omitempty"`
+	Priority string `xml:"priority,attr,omitempty"`
+	//Error    *clientError
+}

xmpp/session.go

@@ -0,0 +1,178 @@
+package xmpp
+
+import (
+	"crypto/tls"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+)
+
+const xmppStreamOpen = "<?xml version='1.0'?><stream:stream to='%s' xmlns='%s' xmlns:stream='%s' version='1.0'>"
+
+type Session struct {
+	// Session info
+	BindJid      string // Jabber ID as provided by XMPP server
+	StreamId     string
+	Features     streamFeatures
+	TlsEnabled   bool
+	lastPacketId int
+
+	// Session interface
+	In  chan interface{}
+	Out chan interface{}
+
+	// read / write
+	socketProxy io.ReadWriter
+	decoder     *xml.Decoder
+
+	// error management
+	err error
+}
+
+func NewSession(conn net.Conn, o Options) (net.Conn, *Session, error) {
+	s := new(Session)
+	s.init(conn, o)
+
+	// starttls
+	var tlsConn net.Conn
+	tlsConn = s.startTlsIfSupported(conn, o.parsedJid.domain)
+	s.reset(conn, tlsConn, o)
+
+	// auth
+	s.auth(o)
+	s.reset(tlsConn, tlsConn, o)
+
+	// bind resource and 'start' XMPP session
+	s.bind(o)
+	s.rfc3921Session(o)
+
+	return tlsConn, s, s.err
+}
+
+func (s *Session) PacketId() string {
+	s.lastPacketId++
+	return fmt.Sprintf("%x", s.lastPacketId)
+}
+
+func (s *Session) init(conn net.Conn, o Options) {
+	s.setProxy(nil, conn, o)
+	s.Features = s.open(o.parsedJid.domain)
+}
+
+func (s *Session) reset(conn net.Conn, newConn net.Conn, o Options) {
+	if s.err != nil {
+		return
+	}
+
+	s.setProxy(conn, newConn, o)
+	s.Features = s.open(o.parsedJid.domain)
+}
+
+// TODO: setProxyLogger ? better name ? This is not a TCP / HTTP proxy
+func (s *Session) setProxy(conn net.Conn, newConn net.Conn, o Options) {
+	if newConn != conn {
+		s.socketProxy = newSocketProxy(newConn, o.PacketLogger)
+	}
+	s.decoder = xml.NewDecoder(s.socketProxy)
+}
+
+func (s *Session) open(domain string) (f streamFeatures) {
+	// Send stream open tag
+	if _, s.err = fmt.Fprintf(s.socketProxy, xmppStreamOpen, domain, nsClient, nsStream); s.err != nil {
+		return
+	}
+
+	// Set xml decoder and extract streamID from reply
+	s.StreamId, s.err = initDecoder(s.decoder) // TODO refactor / rename
+	if s.err != nil {
+		return
+	}
+
+	// extract stream features
+	if s.err = s.decoder.Decode(&f); s.err != nil {
+		s.err = errors.New("stream open decode features: " + s.err.Error())
+	}
+	return
+}
+
+func (s *Session) startTlsIfSupported(conn net.Conn, domain string) net.Conn {
+	if s.err != nil {
+		return conn
+	}
+
+	if s.Features.StartTLS.XMLName.Space+" "+s.Features.StartTLS.XMLName.Local == nsTLS+" starttls" {
+		fmt.Fprintf(s.socketProxy, "<starttls xmlns='urn:ietf:params:xml:ns:xmpp-tls'/>")
+
+		var k tlsProceed
+		if s.err = s.decoder.DecodeElement(&k, nil); s.err != nil {
+			s.err = errors.New("expecting starttls proceed: " + s.err.Error())
+			return conn
+		}
+		s.TlsEnabled = true
+
+		// TODO: add option to accept all TLS certificates: insecureSkipTlsVerify (DefaultTlsConfig.InsecureSkipVerify)
+		DefaultTlsConfig.ServerName = domain
+		var tlsConn *tls.Conn = tls.Client(conn, &DefaultTlsConfig)
+		// We convert existing connection to TLS
+		if s.err = tlsConn.Handshake(); s.err != nil {
+			return tlsConn
+		}
+
+		// We check that cert matches hostname
+		s.err = tlsConn.VerifyHostname(domain)
+		return tlsConn
+	}
+
+	// starttls is not supported => we do not upgrade the connection:
+	return conn
+}
+
+func (s *Session) auth(o Options) {
+	if s.err != nil {
+		return
+	}
+
+	s.err = authSASL(s.socketProxy, s.decoder, s.Features, o.parsedJid.username, o.Password)
+}
+
+func (s *Session) bind(o Options) {
+	if s.err != nil {
+		return
+	}
+
+	// Send IQ message asking to bind to the local user name.
+	var resource = o.parsedJid.resource
+	if resource != "" {
+		fmt.Fprintf(s.socketProxy, "<iq type='set' id='%s'><bind xmlns='%s'><resource>%s</resource></bind></iq>",
+			s.PacketId(), nsBind, resource)
+	} else {
+		fmt.Fprintf(s.socketProxy, "<iq type='set' id='%s'><bind xmlns='%s'/></iq>", s.PacketId(), nsBind)
+	}
+
+	var iq clientIQ
+	if s.err = s.decoder.Decode(&iq); s.err != nil || &iq.Bind == nil {
+		s.err = errors.New("iq bind result missing: " + s.err.Error())
+		return
+	}
+	s.BindJid = iq.Bind.Jid // our local id (with possibly randomly generated resource
+	return
+}
+
+// TODO: remove when ejabberd is fixed: https://github.com/processone/ejabberd/issues/869
+// After the bind, if the session is required (as per old RFC 3921), we send the session open iq
+func (s *Session) rfc3921Session(o Options) {
+	if s.err != nil {
+		return
+	}
+
+	var iq clientIQ
+
+	// TODO: Do no send unconditionally, check if session is optional and omit it
+	fmt.Fprintf(s.socketProxy, "<iq type='set' id='%s'><session xmlns='%s'/></iq>", s.PacketId(), nsSession)
+	if s.err = s.decoder.Decode(&iq); s.err != nil {
+		s.err = errors.New("expecting iq result after session open: " + s.err.Error())
+		return
+	}
+}

xmpp/socket_proxy.go

@@ -0,0 +1,49 @@
+package xmpp
+
+import (
+	"io"
+	"os"
+)
+
+// Mediated Read / Write on socket
+// Used if logFile from Options is not nil
+type socketProxy struct {
+	socket  io.ReadWriter // Actual connection
+	logFile *os.File
+}
+
+func newSocketProxy(conn io.ReadWriter, logFile *os.File) io.ReadWriter {
+	if logFile == nil {
+		return conn
+	} else {
+		return &socketProxy{conn, logFile}
+	}
+}
+
+func (pl *socketProxy) Read(p []byte) (n int, err error) {
+	n, err = pl.socket.Read(p)
+	if n > 0 {
+		pl.logFile.Write([]byte("RECV:\n")) // Prefix
+		if n, err := pl.logFile.Write(p[:n]); err != nil {
+			return n, err
+		}
+		pl.logFile.Write([]byte("\n\n")) // Separator
+	}
+	return
+}
+
+func (pl *socketProxy) Write(p []byte) (n int, err error) {
+	pl.logFile.Write([]byte("SEND:\n")) // Prefix
+	for _, w := range []io.Writer{pl.socket, pl.logFile} {
+		n, err = w.Write(p)
+		if err != nil {
+			return
+		}
+		if n != len(p) {
+			err = io.ErrShortWrite
+			return
+		}
+	}
+	pl.logFile.Write([]byte("\n\n")) // Separator
+	return len(p), nil
+}

xmpp/starttls.go

@@ -0,0 +1,22 @@
+package xmpp
+
+import (
+	"crypto/tls"
+	"encoding/xml"
+)
+
+var DefaultTlsConfig tls.Config
+
+// XMPP Packet Parsing
+type tlsStartTLS struct {
+	XMLName  xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-tls starttls"`
+	Required bool
+}
+
+type tlsProceed struct {
+	XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-tls proceed"`
+}
+
+type tlsFailure struct {
+	XMLName xml.Name `xml:"urn:ietf:params:xml:ns:xmpp-tls failure"`
+}

xmpp/stream.go

@@ -0,0 +1,22 @@
+package xmpp
+
+import "encoding/xml"
+
+// XMPP Packet Parsing
+type streamFeatures struct {
+	XMLName    xml.Name `xml:"http://etherx.jabber.org/streams features"`
+	StartTLS   tlsStartTLS
+	Caps       Caps
+	Mechanisms saslMechanisms
+	Bind       bindBind
+	Session    sessionSession
+	Any        []xml.Name `xml:",any"`
+}
+
+type Caps struct {
+	XMLName xml.Name `xml:"http://jabber.org/protocol/caps c"`
+	Hash    string   `xml:"hash,attr"`
+	Node    string   `xml:"node,attr"`
+	Ver     string   `xml:"ver,attr"`
+	Ext     string   `xml:"ext,attr,omitempty"`
+}