Java tutorial
/* * Copyright (C) 2015 Dominik Schrmann <dominik@dominikschuermann.de> * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.sufficientlysecure.keychain.ui; import android.app.Activity; import android.content.Context; import android.os.AsyncTask; import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.inputmethod.InputMethodManager; import android.widget.EditText; import android.widget.TextView; import org.sufficientlysecure.keychain.R; import org.sufficientlysecure.keychain.securitytoken.SecurityTokenHelper; import org.sufficientlysecure.keychain.ui.CreateKeyActivity.FragAction; import org.sufficientlysecure.keychain.util.Passphrase; import java.security.SecureRandom; import java.util.Arrays; import java.util.HashSet; public class CreateSecurityTokenPinFragment extends Fragment { // view CreateKeyActivity mCreateKeyActivity; EditText mPin; EditText mPinRepeat; TextView mAdminPin; View mBackButton; View mNextButton; // top 20 according to http://datagenetics.com/blog/september32012/index.html // extended from 4 digits to 6 for our use case private static HashSet<String> sPinBlacklist = new HashSet<>( Arrays.asList("123456", "111111", "000000", "121212", "777777", // "1004", makes no sense as "100004", see blog post "200000", "444444", "222222", "696969", "999999", "333333", "555555", "666666", "111222", "131313", "888888", "654321", "200001", "101010", "XXXXXX" // additional: should not be used, as this PIN is entered for resetting the card )); /** * Creates new instance of this fragment */ public static CreateSecurityTokenPinFragment newInstance() { CreateSecurityTokenPinFragment frag = new CreateSecurityTokenPinFragment(); Bundle args = new Bundle(); frag.setArguments(args); return frag; } /** * Checks if text of given EditText is not empty. If it is empty an error is * set and the EditText gets the focus. * * @return true if EditText is not empty */ private static boolean isEditTextNotEmpty(Context context, EditText editText) { boolean output = true; if (editText.getText().length() == 0) { editText.setError(context.getString(R.string.create_key_empty)); editText.requestFocus(); output = false; } else { editText.setError(null); } return output; } private static boolean areEditTextsEqual(EditText editText1, EditText editText2) { Passphrase p1 = new Passphrase(editText1); Passphrase p2 = new Passphrase(editText2); return (p1.equals(p2)); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.create_yubi_key_pin_fragment, container, false); mPin = (EditText) view.findViewById(R.id.create_yubi_key_pin); mPinRepeat = (EditText) view.findViewById(R.id.create_yubi_key_pin_repeat); mAdminPin = (TextView) view.findViewById(R.id.create_yubi_key_admin_pin); mBackButton = view.findViewById(R.id.create_key_back_button); mNextButton = view.findViewById(R.id.create_key_next_button); if (mCreateKeyActivity.mSecurityTokenPin == null) { new AsyncTask<Void, Void, Passphrase>() { @Override protected Passphrase doInBackground(Void... unused) { SecureRandom secureRandom = new SecureRandom(); // min = 8, we choose 8 String adminPin = "" + secureRandom.nextInt(9) + secureRandom.nextInt(9) + secureRandom.nextInt(9) + secureRandom.nextInt(9) + secureRandom.nextInt(9) + secureRandom.nextInt(9) + secureRandom.nextInt(9) + secureRandom.nextInt(9); return new Passphrase(adminPin); } @Override protected void onPostExecute(Passphrase adminPin) { mCreateKeyActivity.mSecurityTokenAdminPin = adminPin; mAdminPin.setText(mCreateKeyActivity.mSecurityTokenAdminPin.toStringUnsafe()); } }.execute(); } else { mAdminPin.setText(mCreateKeyActivity.mSecurityTokenAdminPin.toStringUnsafe()); } mPin.requestFocus(); mBackButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { back(); } }); mNextButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { nextClicked(); } }); return view; } @Override public void onAttach(Context context) { super.onAttach(context); mCreateKeyActivity = (CreateKeyActivity) getActivity(); } private void back() { hideKeyboard(); mCreateKeyActivity.loadFragment(null, FragAction.TO_LEFT); } private void nextClicked() { if (isEditTextNotEmpty(getActivity(), mPin)) { if (!areEditTextsEqual(mPin, mPinRepeat)) { mPinRepeat.setError(getString(R.string.create_key_passphrases_not_equal)); mPinRepeat.requestFocus(); return; } if (mPin.getText().toString().length() < 6) { mPin.setError(getString(R.string.create_key_yubi_key_pin_too_short)); mPin.requestFocus(); return; } if (sPinBlacklist.contains(mPin.getText().toString())) { mPin.setError(getString(R.string.create_key_yubi_key_pin_insecure)); mPin.requestFocus(); return; } mCreateKeyActivity.mSecurityTokenPin = new Passphrase(mPin.getText().toString()); final double version = SecurityTokenHelper.parseOpenPgpVersion(mCreateKeyActivity.mSecurityTokenAid); Fragment frag; if (version >= 3.0) { frag = CreateSecurityTokenAlgorithmFragment.newInstance(); } else { frag = CreateKeyFinalFragment.newInstance(); } hideKeyboard(); mCreateKeyActivity.loadFragment(frag, FragAction.TO_RIGHT); } } private void hideKeyboard() { if (getActivity() == null) { return; } InputMethodManager inputManager = (InputMethodManager) getActivity() .getSystemService(Context.INPUT_METHOD_SERVICE); // check if no view has focus View v = getActivity().getCurrentFocus(); if (v == null) return; inputManager.hideSoftInputFromWindow(v.getWindowToken(), 0); } }