// SASL negotiation. RFC 6120, section 6
func (d *dialer) negotiateSASL(c interfaces.Conn) error {
user := d.getJIDLocalpart()
password := d.password
if err := c.Authenticate(user, password); err != nil {
return xe.ErrAuthenticationFailed
}
// RFC 6120, section 6.3.2. Restart the stream
err := c.SendInitialStreamHeader()
if err != nil {
return err
}
return c.BindResource()
}
// RFC 6120, section 5.4
func (d *dialer) negotiateSTARTTLS(c interfaces.Conn, conn net.Conn) error {
// RFC 6120, section 5.3
mandatoryToNegotiate := c.Features().StartTLS.Required.Local == "required"
if c.Config().SkipTLS && !mandatoryToNegotiate {
return nil
}
// Section 5.2 states:
// "Support for STARTTLS is REQUIRED in XMPP client and server implementations"
if c.Features().StartTLS.XMLName.Local == "" {
return errors.New("xmpp: server doesn't support TLS")
}
if err := d.startTLS(c, conn); err != nil {
return err
}
return c.SendInitialStreamHeader()
}
// RFC 6120, section 4.3.2
func (d *dialer) negotiateStreamFeatures(c interfaces.Conn, conn net.Conn) error {
if err := c.SendInitialStreamHeader(); err != nil {
return err
}
// STARTTLS MUST be the first feature to be negotiated
if err := d.negotiateSTARTTLS(c, conn); err != nil {
return err
}
if registered, err := d.negotiateInBandRegistration(c); err != nil || registered {
return err
}
// SASL negotiation. RFC 6120, section 6
if err := d.negotiateSASL(c); err != nil {
return err
}
//TODO: negotiate other features
return nil
}