ChooseLockGeneric.java revision 6465054995f8470e52ecaf68ea9508a28f8a5363 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.settings;
18
19import android.app.Activity;
20import android.app.admin.DevicePolicyManager;
21import android.content.Context;
22import android.content.Intent;
23import android.os.Bundle;
24import android.preference.Preference;
25import android.preference.PreferenceActivity;
26import android.preference.PreferenceCategory;
27import android.preference.PreferenceScreen;
28import android.security.KeyStore;
29
30import com.android.internal.widget.LockPatternUtils;
31
32public class ChooseLockGeneric extends PreferenceActivity {
33
34    @Override
35    public Intent getIntent() {
36        Intent modIntent = new Intent(super.getIntent());
37        modIntent.putExtra(EXTRA_SHOW_FRAGMENT, ChooseLockGenericFragment.class.getName());
38        modIntent.putExtra(EXTRA_NO_HEADERS, true);
39        return modIntent;
40    }
41
42    public static class ChooseLockGenericFragment extends SettingsPreferenceFragment {
43        private static final int MIN_PASSWORD_LENGTH = 4;
44        private static final String KEY_UNLOCK_SET_OFF = "unlock_set_off";
45        private static final String KEY_UNLOCK_SET_NONE = "unlock_set_none";
46        private static final String KEY_UNLOCK_SET_PIN = "unlock_set_pin";
47        private static final String KEY_UNLOCK_SET_PASSWORD = "unlock_set_password";
48        private static final String KEY_UNLOCK_SET_PATTERN = "unlock_set_pattern";
49        private static final int CONFIRM_EXISTING_REQUEST = 100;
50        private static final String PASSWORD_CONFIRMED = "password_confirmed";
51        private static final String CONFIRM_CREDENTIALS = "confirm_credentials";
52        public static final String MINIMUM_QUALITY_KEY = "minimum_quality";
53
54        private ChooseLockSettingsHelper mChooseLockSettingsHelper;
55        private DevicePolicyManager mDPM;
56        private KeyStore mKeyStore;
57        private boolean mPasswordConfirmed = false;
58
59        @Override
60        public void onCreate(Bundle savedInstanceState) {
61            super.onCreate(savedInstanceState);
62
63            mDPM = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);
64            mKeyStore = KeyStore.getInstance();
65            mChooseLockSettingsHelper = new ChooseLockSettingsHelper(this.getActivity());
66
67            if (savedInstanceState != null) {
68                mPasswordConfirmed = savedInstanceState.getBoolean(PASSWORD_CONFIRMED);
69            }
70
71            if (!mPasswordConfirmed) {
72                ChooseLockSettingsHelper helper =
73                        new ChooseLockSettingsHelper(this.getActivity(), this);
74                if (!helper.launchConfirmationActivity(CONFIRM_EXISTING_REQUEST, null, null)) {
75                    mPasswordConfirmed = true; // no password set, so no need to confirm
76                    updatePreferencesOrFinish();
77                }
78            } else {
79                updatePreferencesOrFinish();
80            }
81        }
82
83        @Override
84        public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen,
85                Preference preference) {
86            final String key = preference.getKey();
87            boolean handled = true;
88            if (KEY_UNLOCK_SET_OFF.equals(key)) {
89                updateUnlockMethodAndFinish(
90                        DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED, true);
91            } else if (KEY_UNLOCK_SET_NONE.equals(key)) {
92                updateUnlockMethodAndFinish(
93                        DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED, false);
94            } else if (KEY_UNLOCK_SET_PATTERN.equals(key)) {
95                updateUnlockMethodAndFinish(
96                        DevicePolicyManager.PASSWORD_QUALITY_SOMETHING, false);
97            } else if (KEY_UNLOCK_SET_PIN.equals(key)) {
98                updateUnlockMethodAndFinish(
99                        DevicePolicyManager.PASSWORD_QUALITY_NUMERIC, false);
100            } else if (KEY_UNLOCK_SET_PASSWORD.equals(key)) {
101                updateUnlockMethodAndFinish(
102                        DevicePolicyManager.PASSWORD_QUALITY_ALPHABETIC, false);
103            } else {
104                handled = false;
105            }
106            return handled;
107        }
108
109        @Override
110        public void onActivityResult(int requestCode, int resultCode, Intent data) {
111            super.onActivityResult(requestCode, resultCode, data);
112            if (requestCode == CONFIRM_EXISTING_REQUEST && resultCode == Activity.RESULT_OK) {
113                mPasswordConfirmed = true;
114                updatePreferencesOrFinish();
115            } else {
116                getActivity().setResult(Activity.RESULT_CANCELED);
117                finish();
118            }
119        }
120
121        @Override
122        public void onSaveInstanceState(Bundle outState) {
123            super.onSaveInstanceState(outState);
124            // Saved so we don't force user to re-enter their password if configuration changes
125            outState.putBoolean(PASSWORD_CONFIRMED, mPasswordConfirmed);
126        }
127
128        private void updatePreferencesOrFinish() {
129            int quality = getActivity().getIntent()
130                    .getIntExtra(LockPatternUtils.PASSWORD_TYPE_KEY, -1);
131            if (quality == -1) {
132                // If caller didn't specify password quality, show UI and allow the user to choose.
133                quality = getActivity().getIntent().getIntExtra(MINIMUM_QUALITY_KEY, -1);
134                quality = upgradeQuality(quality);
135                final PreferenceScreen prefScreen = getPreferenceScreen();
136                if (prefScreen != null) {
137                    prefScreen.removeAll();
138                }
139                addPreferencesFromResource(R.xml.security_settings_picker);
140                disableUnusablePreferences(quality);
141            } else {
142                updateUnlockMethodAndFinish(quality, false);
143            }
144        }
145
146        private int upgradeQuality(int quality) {
147            quality = upgradeQualityForDPM(quality);
148            quality = upgradeQualityForEncryption(quality);
149            quality = upgradeQualityForKeyStore(quality);
150            return quality;
151        }
152
153        private int upgradeQualityForDPM(int quality) {
154            // Compare min allowed password quality
155            int minQuality = mDPM.getPasswordQuality(null);
156            if (quality < minQuality) {
157                quality = minQuality;
158            }
159            return quality;
160        }
161
162        /**
163         * Mix in "encryption minimums" to any given quality value.  This prevents users
164         * from downgrading the pattern/pin/password to a level below the minimums.
165         *
166         * ASSUMPTION:  Setting quality is sufficient (e.g. minimum lengths will be set
167         * appropriately.)
168         */
169        private int upgradeQualityForEncryption(int quality) {
170            int encryptionStatus = mDPM.getStorageEncryptionStatus();
171            boolean encrypted = (encryptionStatus == DevicePolicyManager.ENCRYPTION_STATUS_ACTIVE)
172                    || (encryptionStatus == DevicePolicyManager.ENCRYPTION_STATUS_ACTIVATING);
173            if (encrypted) {
174                if (quality < CryptKeeperSettings.MIN_PASSWORD_QUALITY) {
175                    quality = CryptKeeperSettings.MIN_PASSWORD_QUALITY;
176                }
177            }
178            return quality;
179        }
180
181        private int upgradeQualityForKeyStore(int quality) {
182            if (!mKeyStore.isEmpty()) {
183                if (quality < CredentialStorage.MIN_PASSWORD_QUALITY) {
184                    quality = CredentialStorage.MIN_PASSWORD_QUALITY;
185                }
186            }
187            return quality;
188        }
189
190        /***
191         * Disables preferences that are less secure than required quality.
192         *
193         * @param quality the requested quality.
194         */
195        private void disableUnusablePreferences(final int quality) {
196            final Preference picker =
197                    getPreferenceScreen().findPreference("security_picker_category");
198            final PreferenceCategory cat = (PreferenceCategory) picker;
199            final int preferenceCount = cat.getPreferenceCount();
200            for (int i = 0; i < preferenceCount; i++) {
201                Preference pref = cat.getPreference(i);
202                if (pref instanceof PreferenceScreen) {
203                    final String key = ((PreferenceScreen) pref).getKey();
204                    boolean enabled = true;
205                    if (KEY_UNLOCK_SET_OFF.equals(key)) {
206                        enabled = quality <= DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED;
207                    } else if (KEY_UNLOCK_SET_NONE.equals(key)) {
208                        enabled = quality <= DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED;
209                    } else if (KEY_UNLOCK_SET_PATTERN.equals(key)) {
210                        enabled = quality <= DevicePolicyManager.PASSWORD_QUALITY_SOMETHING;
211                    } else if (KEY_UNLOCK_SET_PIN.equals(key)) {
212                        enabled = quality <= DevicePolicyManager.PASSWORD_QUALITY_NUMERIC;
213                    } else if (KEY_UNLOCK_SET_PASSWORD.equals(key)) {
214                        enabled = quality <= DevicePolicyManager.PASSWORD_QUALITY_COMPLEX;
215                    }
216                    if (!enabled) {
217                        pref.setSummary(R.string.unlock_set_unlock_disabled_summary);
218                        pref.setEnabled(false);
219                    }
220                }
221            }
222        }
223
224        /**
225         * Invokes an activity to change the user's pattern, password or PIN based on given quality
226         * and minimum quality specified by DevicePolicyManager. If quality is
227         * {@link DevicePolicyManager#PASSWORD_QUALITY_UNSPECIFIED}, password is cleared.
228         *
229         * @param quality the desired quality. Ignored if DevicePolicyManager requires more security
230         * @param disabled whether or not to show LockScreen at all. Only meaningful when quality is
231         * {@link DevicePolicyManager#PASSWORD_QUALITY_UNSPECIFIED}
232         */
233        void updateUnlockMethodAndFinish(int quality, boolean disabled) {
234            // Sanity check. We should never get here without confirming user's existing password.
235            if (!mPasswordConfirmed) {
236                throw new IllegalStateException("Tried to update password without confirming it");
237            }
238
239            quality = upgradeQuality(quality);
240            if (quality >= DevicePolicyManager.PASSWORD_QUALITY_NUMERIC) {
241                int minLength = mDPM.getPasswordMinimumLength(null);
242                if (minLength < MIN_PASSWORD_LENGTH) {
243                    minLength = MIN_PASSWORD_LENGTH;
244                }
245                final int maxLength = mDPM.getPasswordMaximumLength(quality);
246                Intent intent = new Intent().setClass(getActivity(), ChooseLockPassword.class);
247                intent.putExtra(LockPatternUtils.PASSWORD_TYPE_KEY, quality);
248                intent.putExtra(ChooseLockPassword.PASSWORD_MIN_KEY, minLength);
249                intent.putExtra(ChooseLockPassword.PASSWORD_MAX_KEY, maxLength);
250                intent.putExtra(CONFIRM_CREDENTIALS, false);
251                intent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
252                startActivity(intent);
253            } else if (quality == DevicePolicyManager.PASSWORD_QUALITY_SOMETHING) {
254                boolean showTutorial = !mChooseLockSettingsHelper.utils().isPatternEverChosen();
255                Intent intent = new Intent();
256                intent.setClass(getActivity(), showTutorial
257                        ? ChooseLockPatternTutorial.class
258                        : ChooseLockPattern.class);
259                intent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
260                intent.putExtra("key_lock_method", "pattern");
261                intent.putExtra(CONFIRM_CREDENTIALS, false);
262                startActivity(intent);
263            } else if (quality == DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED) {
264                mChooseLockSettingsHelper.utils().clearLock();
265                mChooseLockSettingsHelper.utils().setLockScreenDisabled(disabled);
266                getActivity().setResult(Activity.RESULT_OK);
267            }
268            finish();
269        }
270    }
271}
272