update Secrets

app/src/main/java/im/status/applet_installer_test/appletinstaller/Secrets.java

@@ -0,0 +1,90 @@
+package im.status.applet_installer_test.appletinstaller;
+
+import android.support.annotation.NonNull;
+import android.util.Base64;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.security.spec.InvalidKeySpecException;
+
+import javax.crypto.SecretKey;
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+import static android.util.Base64.NO_PADDING;
+
+public class Secrets {
+    private String pin;
+    private String puk;
+    private String pairingPassword;
+    private byte[] pairingToken;
+
+    private static long PIN_BOUND = 999999L;
+    private static long PUK_BOUND = 999999999999L;
+
+    public Secrets(String pin, String puk, String pairingPassword, byte[] pairingToken) {
+        this.pin = pin;
+        this.puk = puk;
+        this.pairingPassword = pairingPassword;
+        this.pairingToken = pairingToken;
+    }
+
+    @NonNull
+    public static Secrets generate() throws NoSuchAlgorithmException, InvalidKeySpecException {
+        String pairingPassword = randomToken(12);
+        byte[] pairingToken = generatePairingKey(pairingPassword.toCharArray());
+        long pinNumber = randomLong(PIN_BOUND);
+        long pukNumber = randomLong(PUK_BOUND);
+        String pin = String.format("%06d", pinNumber);
+        String puk = String.format("%012d", pukNumber);
+
+        return new Secrets(pin, puk, pairingPassword, pairingToken);
+    }
+
+    public static Secrets testSecrets() throws NoSuchAlgorithmException, InvalidKeySpecException {
+        String pairingPassword = "WalletAppletTest";
+        byte[] pairingToken = generatePairingKey(pairingPassword.toCharArray());
+        return new Secrets("000000", "123456789012", pairingPassword, pairingToken);
+    }
+
+    public String getPin() {
+        return pin;
+    }
+
+    public String getPuk() {
+        return puk;
+    }
+
+    public String getPairingPassword() {
+        return pairingPassword;
+    }
+
+    public byte[] getPairingToken() {
+        return pairingToken;
+    }
+
+    public static byte[] randomBytes(int length) {
+        SecureRandom random = new SecureRandom();
+        byte data[] = new byte[length];
+        random.nextBytes(data);
+
+        return data;
+    }
+
+    public static String randomToken(int length) {
+        return Base64.encodeToString(randomBytes(length), NO_PADDING);
+    }
+
+    public static long randomLong(long bound) {
+        SecureRandom random = new SecureRandom();
+        return Math.abs(random.nextLong()) % bound;
+    }
+
+    public static byte[] generatePairingKey(char[] pairing) throws NoSuchAlgorithmException, InvalidKeySpecException {
+        SecretKeyFactory skf = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
+        String salt = "Status Hardware Wallet Lite";
+        PBEKeySpec spec = new PBEKeySpec(pairing, salt.getBytes(), 50000, 32*8);
+        SecretKey key = skf.generateSecret(spec);
+
+        return key.getEncoded();
+    }
+}