Checkpoint 5

hash/godoor_test.go

@@ -0,0 +1,40 @@
+package hash
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestHash(t *testing.T) {
+	hash := HashCardUid(0x000000000F0AD2301)
+	if hash != "a6d9ba36ecb5f8e6312f40ee260ad59e9cca3c6ce073bf072df3324c0072886196e6823a7c758ab567fc53e91fbbda297a4efe0072e41316c56446ef126a5180" {
+		t.Errorf("WRONG Key generated: %q", hash)
+	}
+
+	hash = HashCardUid(0x3CBB5AAD)
+	if hash != "1e7bbc1aeeff4bfe58ea8d97df7cd0f97599fa31633d3a1f57d138549b3968c20affb186fe0b85570d34718b273d269bcd28b2be59faf8122451d91a2cdc5f18" {
+		t.Errorf("WRONG Key generated: %q", hash)
+	}
+}
+
+func TestBits(t *testing.T) {
+
+	bits := make([]bool, 64)
+	trueBits := []int{0, 1, 2, 3, 8, 10, 12, 13, 15, 18, 22, 23, 31}
+	for _, i := range trueBits {
+		bits[i] = true
+	}
+
+	var card uint64 = 0
+	for i := 63; i >= 0; i-- {
+		if bits[i] == true {
+			card |= 1 << (63 - i)
+		}
+	}
+
+	cardId := fmt.Sprintf("%x", card)
+	fmt.Println(cardId)
+	if card != 0xF0AD230100000000 {
+		panic(fmt.Errorf("WROOONG: %x", card))
+	}
+}

hash/hash.go

@@ -0,0 +1,21 @@
+package hash
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+
+	"golang.org/x/crypto/scrypt"
+)
+
+func HashCardUid(card uint64) string {
+	b := make([]byte, 8)
+	binary.LittleEndian.PutUint64(b, card)
+
+	hashed, err := scrypt.Key(b, []byte("hkRXwLlQKmCJoy5qaahp"), 16384, 8, 1, 64)
+	if err != nil {
+		panic(err) // can only happen when scrypt params are garbage
+	}
+
+	hashedHex := hex.EncodeToString(hashed)
+	return hashedHex
+}