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|
package xmpp
import (
"encoding/xml"
"encoding/base64"
"errors"
"log"
)
type tokenRouter struct {
start xml.StartElement
end xml.EndElement
buffer []xml.Token
level uint16 // XML nesting level
enc *encoder
}
func newTokenRouter() tokenRouter {
return tokenRouter{
buffer: make([]xml.Token, 0),
level: 0,
}
}
func (r *tokenRouter) route(t xml.Token, c *Conn) error {
r.buffer = append(r.buffer, t)
switch unwrapped := t.(type) {
case xml.StartElement:
r.level += 1
if r.level == 1 {
r.start = unwrapped
r.buffer = r.buffer[:0]
// call start handler
}
case xml.EndElement:
if r.level == 0 {
log.Println("Ignoring XML end element on nesting level zero")
return nil
}
r.level -= 1
switch r.level {
case 0:
return errors.New("Stream was closed by server")
case 1:
err := routeElement(r.buffer, c)
if err != nil {
return err
}
r.buffer = r.buffer[:0]
}
case xml.ProcInst:
log.Println("Ignoring xml.ProcInst element")
r.buffer = r.buffer[:len(r.buffer)-1]
case xml.Directive:
log.Println("Ignoring xml.Directive element")
r.buffer = r.buffer[:len(r.buffer)-1]
case xml.Comment:
log.Println("Ignoring xml.Comment element")
r.buffer = r.buffer[:len(r.buffer)-1]
}
return nil
}
func routeElement(b []xml.Token, c *Conn) error {
tab := elementRoutingTable{
{xml.Name{"http://etherx.jabber.org/streams", "features"}, streamFeatures},
}
switch unwrapped := b[0].(type) {
case xml.StartElement:
for _, v := range(tab) {
if unwrapped.Name == v.name {
err := v.handler(b, c)
if err != nil {
return err
}
return nil
}
}
log.Printf("Ignoring XML element '%s' from namespace '%s'",
unwrapped.Name.Local, unwrapped.Name.Space)
default:
log.Println("Ignoring XML element which has no StartElement as first token")
}
return nil
}
type elementRoutingTable []struct {
name xml.Name
handler func(b []xml.Token, c *Conn) error
}
func streamFeatures(b []xml.Token, c *Conn) error {
err := sendSaslAuth(b, c)
if err != nil {
return err
}
return nil
}
func sendSaslAuth(b []xml.Token, c *Conn) error {
mechanisms := make([]string, 0)
for i, v := range(b) {
switch token := v.(type) {
case xml.StartElement:
expected := xml.Name{"urn:ietf:params:xml:ns:xmpp-sasl", "mechanism"}
if token.Name == expected {
if i >= (len(b)-1) { continue }
switch payload := b[i+1].(type) {
case xml.CharData:
mechanisms = append(mechanisms, string(payload))
}
}
}
}
for _, v := range(mechanisms) {
if v == "PLAIN" {
start := xml.StartElement{
xml.Name{"urn:ietf:params:xml:ns:xmpp-sasl", "auth"},
[]xml.Attr{
xml.Attr{xml.Name{"", "mechanism"}, "PLAIN"},
},
}
data := []byte("\x00" + username(c.jid) + "\x00" + c.pwd)
dst := make([]byte, base64.StdEncoding.EncodedLen(len(data)))
base64.StdEncoding.Encode(dst, data)
payload := xml.CharData(dst)
end := start.End()
c.enc.encodeNow(start)
c.enc.encode(payload)
c.enc.encodeNow(end)
return nil
}
}
return errors.New("No compatible SASL mechanism given")
}
|
