reorganize code

core/model/keypad_size.go

@@ -0,0 +1,19 @@
+package model
+
+type KeypadSize struct {
+	AttrsPerKey int `json:"attrs_per_key"`
+	NumbOfKeys  int `json:"numb_of_keys"`
+}
+
+func (kp *KeypadSize) TotalAttrs() int {
+	return kp.AttrsPerKey * kp.NumbOfKeys
+}
+
+func (kp *KeypadSize) IsDispersable() bool {
+	return kp.AttrsPerKey <= kp.NumbOfKeys
+}
+
+type EncipheredNKode struct {
+	Code string
+	Mask string
+}