go-xmpp/auth.go

54 lines
1.5 KiB
Go

package xmpp
import (
"encoding/base64"
"encoding/xml"
"errors"
"fmt"
"io"
"gosrc.io/xmpp/stanza"
)
func authSASL(socket io.ReadWriter, decoder *xml.Decoder, f stanza.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 {
err := fmt.Errorf("PLAIN authentication is not supported by server: %v", f.Mechanisms.Mechanism)
return NewConnError(err, true)
}
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>", stanza.NSSASL, enc)
// Next message should be either success or failure.
val, err := stanza.NextPacket(decoder)
if err != nil {
return err
}
switch v := val.(type) {
case stanza.SASLSuccess:
case stanza.SASLFailure:
// v.Any is type of sub-element in failure, which gives a description of what failed.
err := errors.New("auth failure: " + v.Any.Local)
return NewConnError(err, true)
default:
return errors.New("expected SASL success or failure, got " + v.Name())
}
return err
}