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|
package main
import (
"crypto/tls"
"crypto/x509"
"encoding/xml"
"log"
"os"
)
type XmppEvent uint8
const (
XmppDisconnect XmppEvent = iota
XmppConnect
)
func xmpp(rxChan chan GuiEvent, txChan chan any, jid string, pwd string) {
conn, err := setupConn(jid)
if err != nil {
log.Print(err)
return
}
defer conn.Close()
receiver := newXmppReceiver(conn)
go receiver.run()
defer receiver.stop()
enc := xml.NewEncoder(conn)
defer enc.Close()
dbg := xml.NewEncoder(os.Stdout)
defer dbg.Close()
end := sendStreamStart(enc, dbg, jid)
defer sendStreamEnd(enc, dbg, end)
txChan <- XmppConnect
defer func() { txChan <- XmppDisconnect }()
for {
select {
case ev := <-rxChan:
switch ev {
case Disconnect:
return
default:
log.Printf("Unknown GuiEvent '%d'!\n", ev)
}
case rx := <-receiver.data:
dbg.Indent("S: ", " ")
dbg.EncodeToken(rx)
dbg.Flush()
}
}
}
type xmppReceiver struct {
terminator chan bool
data chan xml.Token
decoder *xml.Decoder
}
func newXmppReceiver(conn *tls.Conn) xmppReceiver {
return xmppReceiver{
make(chan bool),
make(chan xml.Token),
xml.NewDecoder(conn),
}
}
func (r *xmppReceiver) run() {
for {
select {
case <-r.terminator:
return
default:
t, err := r.decoder.Token()
if err != nil {
log.Print(err)
}
if t != nil {
c := xml.CopyToken(t)
r.data <- c
}
}
}
}
func (r *xmppReceiver) stop() {
r.terminator <- true
}
func setupConn(jid string) (*tls.Conn, error) {
domain := domainpart(jid)
roots, err := x509.SystemCertPool()
if err != nil {
return nil, err
}
return tls.Dial("tcp", domain+":"+"5223", &tls.Config{RootCAs: roots})
}
func sendStreamStart(enc *xml.Encoder, dbg *xml.Encoder, jid string) xml.EndElement {
start := xml.StartElement{
xml.Name{"jabber:client", "stream:stream"},
[]xml.Attr{
xml.Attr{xml.Name{"", "from"}, jid},
xml.Attr{xml.Name{"", "to"}, domainpart(jid)},
xml.Attr{xml.Name{"", "version"}, "1.0"},
xml.Attr{xml.Name{"", "xml:lang"}, "en"},
xml.Attr{xml.Name{"", "xmlns:stream"}, "http://etherx.jabber.org/streams"},
},
}
err := enc.EncodeToken(start)
if err != nil {
log.Println("Could not encode stream start to TCP channel!")
}
err = enc.Flush()
if err != nil {
log.Println("Could not flush TCP channel XML encoder!")
}
dbg.Indent("C: ", " ")
err = dbg.EncodeToken(start)
if err != nil {
log.Println("Could not encode stream start to debug output!")
}
err = dbg.Flush()
if err != nil {
log.Println("Could not flush debug XML encoder!")
}
return start.End()
}
func sendStreamEnd(enc *xml.Encoder, dbg *xml.Encoder, end xml.EndElement) {
err := enc.EncodeToken(end)
if err != nil {
log.Println("Could not encode stream end to TCP channel!")
}
err = enc.Flush()
if err != nil {
log.Println("Could not flush TCP channel XML encoder!")
}
dbg.Indent("C: ", " ")
err = dbg.EncodeToken(end)
if err != nil {
log.Println("Could not encode stream end to debug output!")
}
err = dbg.Flush()
if err != nil {
log.Println("Could not flush debug XML encoder!")
}
}
// domainpart extracts the domain name from a JID / XMPP address. See
// https://datatracker.ietf.org/doc/html/rfc7622#section-3.2 for details.
func domainpart(jid string) string {
list := []rune(jid)
for i, v := range list {
if v == '/' {
list = list[:i]
break
}
}
for i, v := range list {
if v == '@' {
list = list[i+1:]
break
}
}
return string(list)
}
|
