Add component API and example.

component.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"flag"
+	"log"
+	"xmpp"
+)
+
+func main() {
+
+	jid := flag.String("jid", "", "JID")
+	secret := flag.String("secret", "", "Component secret")
+	flag.Parse()
+
+	jid2, err := xmpp.ParseJID(*jid)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	c, err := xmpp.NewComponent("localhost:5347", jid2, *secret)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	log.Println(c)
+	select {}
+}

src/xmpp/component.go

@@ -0,0 +1,86 @@
+package xmpp
+
+import (
+	"crypto/sha1"
+	"encoding/xml"
+	"errors"
+	"fmt"
+	"log"
+)
+
+type component struct {
+	jid JID
+	stream *Stream
+}
+
+func NewComponent(addr string, jid JID, secret string) (*component, error) {
+
+	stream, err := NewStream(addr)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := stream.Send("<?xml version='1.0'?>"); err != nil {
+		return nil, err
+	}
+
+	streamId, err := startComponent(stream, jid)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := handshake(stream, streamId, secret); err != nil {
+		return nil, err
+	}
+
+	return &component{jid, stream}, nil
+}
+
+func startComponent(stream *Stream, jid JID) (string, error) {
+
+	s := fmt.Sprintf(
+		"<stream:stream xmlns='jabber:component:accept' xmlns:stream='http://etherx.jabber.org/streams' to='%s'>",
+		jid)
+	if err := stream.Send(s); err != nil {
+		return "", err
+	}
+
+	streamId := ""
+	if e, err := stream.Next(&xml.Name{nsStream, "stream"}); err != nil {
+		return "", err
+	} else {
+		// Find the stream id.
+		for _, attr := range e.Attr {
+			if attr.Name.Local == "id" {
+				streamId = attr.Value
+				break
+			}
+		}
+		if streamId == "" {
+			return "", errors.New("Missing stream id")
+		}
+	}
+
+	return streamId, nil
+}
+
+func handshake(stream *Stream, streamId, secret string) error {
+
+	hash := sha1.New()
+	hash.Write([]byte(streamId))
+	hash.Write([]byte(secret))
+
+	// Send handshake.
+	s := fmt.Sprintf("<handshake>%x</handshake>", hash.Sum(nil))
+	log.Println(s)
+	if err := stream.Send(s); err != nil {
+		return err
+	}
+
+	// Get handshake response.
+	if _, err := stream.Next(&xml.Name{"jabber:component:accept", "handshake"}); err != nil {
+		return err
+	}
+
+	return nil
+}