func (this *Server) handleConnection(out net.Conn, ip net.IP, port int) {
req, err := msg.DecodeMessage(out)
if err != nil {
log.Println(err)
return
}
conn := &Connection{Req: req, Out: out, Realm: Realm}
switch req.Type() {
case msg.Binding | msg.Request:
if this.auth == nil {
log.Println("Binding to address:", ip, port)
res := msg.NewResponse(msg.Success, req)
xorAddr := msg.NewXORAddress(ip, port, res.Header())
res.AddAttribute(xorAddr)
out.Write(res.EncodeMessage())
this.conns <- conn
return
}
if this.Validate(conn) {
conn.Write(msg.NewResponse(msg.Success, req))
this.conns <- conn
}
default: // Unrecognized messages
this.conns <- conn
}
}
// If the request is not valid this function sends a proper message back to the
// client. Updates user, passwd, and realm fields in conn. Not all fields are
// guaranteed to be correct unless Validate() return true
func (this *Server) Validate(conn *Connection) bool {
req := conn.Req
// Request attributes
integrity, iErr := req.Attribute(msg.MessageIntegrity)
user, uErr := req.Attribute(msg.Username)
_, rErr := req.Attribute(msg.Realm)
nonce, nErr := req.Attribute(msg.Nonce)
ok := false
// Response attributes
res := msg.NewResponse(msg.Error, req)
n := msg.NewNonce()
if uErr == nil {
conn.User = user.(*msg.UserAttr).String()
conn.Passwd, ok = this.auth.Password(conn.User)
if ok {
conn.HasAuth = true
}
}
if iErr != nil {
// Reject request
e, _ := msg.NewErrorAttr(msg.Unauthorized, "Unauthorized")
res.AddAttribute(e)
res.AddAttribute(this.realm)
res.AddAttribute(n)
log.Println("No Integrity")
conn.Write(res)
return false
} else if uErr != nil || rErr != nil || nErr != nil {
// Reject request
e, _ := msg.NewErrorAttr(msg.BadRequest, "Bad Request")
res.AddAttribute(e)
log.Println("Missing user, nonce, or realm")
conn.Write(res)
return false
} else if !ok {
// Reject request
res := msg.NewResponse(msg.Error, req)
e, _ := msg.NewErrorAttr(msg.Unauthorized, "User Not Found")
res.AddAttribute(e)
res.AddAttribute(this.realm)
res.AddAttribute(n)
log.Println("User Not Found")
conn.Write(res)
return false
} else if !msg.ValidNonce(nonce) {
// Reject request
e, _ := msg.NewErrorAttr(msg.StaleNonce, "Stale Nonce")
res.AddAttribute(e)
res.AddAttribute(this.realm)
res.AddAttribute(n)
log.Println("Invalid Nonce")
conn.Write(res)
return false
} else if !msg.ToIntegrity(integrity).Valid(conn.User, conn.Passwd, Realm, req) {
e, _ := msg.NewErrorAttr(msg.Unauthorized, "Unauthorized")
res.AddAttribute(e)
res.AddAttribute(this.realm)
res.AddAttribute(n)
log.Println("Invalid integrity")
conn.Write(res)
return false
}
return true
}