Checkpoint 2

wiegand.go

@@ -12,7 +12,12 @@ import (
 	"github.com/warthog618/gpiod"
 )
 
-type Wiegand struct {
+type Wiegand interface {
+	GetCardUid() (uint64, error)
+	OpenDoor()
+}
+
+type WiegandHW struct {
 	aLine           *gpiod.Line
 	bLine           *gpiod.Line
 	bits            [64]bool
@@ -23,7 +28,7 @@ type Wiegand struct {
 	solenoidLine *gpiod.Line
 }
 
-func (w *Wiegand) OpenDoor() {
+func (w *WiegandHW) OpenDoor() {
 	fmt.Println("Open")
 	w.solenoidLine.SetValue(1)
 	d, _ := time.ParseDuration("500ms")
@@ -39,65 +44,58 @@ func printCardId(card uint64) {
 	fmt.Printf("\n")
 }
 
-func (w *Wiegand) cardRunner(validUids ValidUids) {
-	for {
-		// Wait for bit timeout
-		fmt.Printf("Waiting for bit timeout\n")
-		<-w.bitTimeoutTimer.C
-		fmt.Printf("\n")
-
-		if w.bitNr != 64 {
-			fmt.Printf("We got less than 64 bits: %d\n", w.bitNr)
-		}
-
-		var card uint64 = 0
-		for i := 63; i != 0; i-- {
-			if w.bits[i] == true {
-				card |= 1 << (63 - i)
-			}
-		}
-
-		printCardId(card)
-
-		b := make([]byte, 8)
-		binary.LittleEndian.PutUint64(b, card)
-		hashed, err := scrypt.Key(b, []byte("hashsah"), 16384, 8, 1, 64)
-		if err != nil {
-			panic(err)
-		}
-
-		hashedHex := hex.EncodeToString(hashed)
-		fmt.Println(hashedHex)
-
-		_, ok := validUids[hashedHex]
-		if ok {
-			fmt.Println("Opening door")
-			w.OpenDoor()
-		} else {
-			fmt.Println("Unknown card")
-		}
-
-		w.bitNr = 0
+func hashCardUid(card uint64) string {
+	b := make([]byte, 8)
+	binary.LittleEndian.PutUint64(b, card)
+	hashed, err := scrypt.Key(b, []byte(config.uid_salt), 16384, 8, 1, 64)
+	if err != nil {
+		panic(err) // can only happen when scrypt params are garbage
 	}
+
+	hashedHex := hex.EncodeToString(hashed)
+	return hashedHex
 }
 
-func (w *Wiegand) wiegandAEvent(evt gpiod.LineEvent) {
+func (w *WiegandHW) GetCardUid() (uint64, error) {
+	// Wait for bit timeout
+	fmt.Printf("Waiting for bit timeout\n")
+
+	<-w.bitTimeoutTimer.C
+	fmt.Printf("\n")
+
+	defer func() { w.bitNr = 0 }()
+
+	if w.bitNr != 64 {
+		return 0, fmt.Errorf("We got less than 64 bits: %d\n", w.bitNr)
+	}
+
+	var card uint64 = 0
+	for i := 63; i != 0; i-- {
+		if w.bits[i] == true {
+			card |= 1 << (63 - i)
+		}
+	}
+
+	return card, nil
+}
+
+func (w *WiegandHW) wiegandAEvent(evt gpiod.LineEvent) {
 	w.bitTimeoutTimer.Reset(w.bitTimeout)
 	w.bits[w.bitNr] = false
 	fmt.Printf("0")
 	w.bitNr += 1
 }
 
-func (w *Wiegand) wiegandBEvent(evt gpiod.LineEvent) {
+func (w *WiegandHW) wiegandBEvent(evt gpiod.LineEvent) {
 	w.bitTimeoutTimer.Reset(w.bitTimeout)
 	w.bits[w.bitNr] = true
 	fmt.Printf("1")
 	w.bitNr += 1
 }
 
-func WiegandSetup(a int, b int, bitTimeout time.Duration, solenoid int) *Wiegand {
+func WiegandSetup(a int, b int, bitTimeout time.Duration, solenoid int) *WiegandHW {
 
-	var wiegand Wiegand
+	var wiegand WiegandHW
 	wiegand.bitTimeout = bitTimeout
 
 	wiegand.bitTimeoutTimer = time.NewTimer(wiegand.bitTimeout)
@@ -128,7 +126,7 @@ func WiegandSetup(a int, b int, bitTimeout time.Duration, solenoid int) *Wiegand
 	return &wiegand
 }
 
-func (w *Wiegand) WiegandClose() {
+func (w *WiegandHW) WiegandClose() {
 	w.aLine.Close()
 	w.bLine.Close()
 	w.solenoidLine.Close()