error checks

client/TGSExchange.go

@@ -68,6 +68,9 @@ func (cl *Client) GetServiceTicket(spn string) (messages.Ticket, types.Encryptio
 	realm := cl.Config.ResolveRealm(princ.NameString[len(princ.NameString)-1])
 
 	tgt, skey, err := cl.sessionTGT(realm)
+	if err != nil {
+		return tkt, skey, err
+	}
 
 	_, tgsRep, err := cl.TGSExchange(princ, realm, tgt, skey, false, 0)
 	if err != nil {

client/client.go

@@ -229,6 +229,9 @@ func (cl *Client) realmLogin(realm string) error {
 		}
 	}
 	tgt, skey, err := cl.sessionTGT(cl.Credentials.Realm)
+	if err != nil {
+		return err
+	}
 
 	spn := types.PrincipalName{
 		NameType:   nametype.KRB_NT_SRV_INST,