KeyguardSecurityModel.java revision 9ded0e1d48c016883858dd2dc574787524c6df84 
1/*
2 * Copyright (C) 2012 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 */
16package com.android.internal.policy.impl.keyguard;
17
18import android.app.admin.DevicePolicyManager;
19import android.content.Context;
20
21import com.android.internal.telephony.IccCardConstants;
22import com.android.internal.widget.LockPatternUtils;
23
24public class KeyguardSecurityModel {
25    /**
26     * The different types of security available for {@link Mode#UnlockScreen}.
27     * @see com.android.internal.policy.impl.LockPatternKeyguardView#getUnlockMode()
28     */
29    enum SecurityMode {
30        None, // No security enabled
31        Pattern, // Unlock by drawing a pattern.
32        Password, // Unlock by entering a password or PIN
33        Biometric, // Unlock with a biometric key (e.g. finger print or face unlock)
34        Account, // Unlock by entering an account's login and password.
35        SimPin, // Unlock by entering a sim pin.
36        SimPuk // Unlock by entering a sim puk
37    }
38
39    private Context mContext;
40    private LockPatternUtils mLockPatternUtils;
41
42    KeyguardSecurityModel(Context context) {
43        mContext = context;
44        mLockPatternUtils = new LockPatternUtils(context);
45    }
46
47    void setLockPatternUtils(LockPatternUtils utils) {
48        mLockPatternUtils = utils;
49    }
50
51    /**
52     * Returns true if biometric unlock is installed and selected.  If this returns false there is
53     * no need to even construct the biometric unlock.
54     */
55    private boolean isBiometricUnlockEnabled() {
56        return mLockPatternUtils.usingBiometricWeak()
57                && mLockPatternUtils.isBiometricWeakInstalled();
58    }
59
60    /**
61     * Returns true if a condition is currently suppressing the biometric unlock.  If this returns
62     * true there is no need to even construct the biometric unlock.
63     */
64    private boolean isBiometricUnlockSuppressed() {
65        KeyguardUpdateMonitor monitor = KeyguardUpdateMonitor.getInstance(mContext);
66        final boolean backupIsTimedOut = monitor.getFailedUnlockAttempts() >=
67                LockPatternUtils.FAILED_ATTEMPTS_BEFORE_TIMEOUT;
68        return monitor.getMaxBiometricUnlockAttemptsReached() || backupIsTimedOut;
69    }
70
71    SecurityMode getSecurityMode() {
72        KeyguardUpdateMonitor updateMonitor = KeyguardUpdateMonitor.getInstance(mContext);
73        final IccCardConstants.State simState = updateMonitor.getSimState();
74        SecurityMode mode = SecurityMode.None;
75        if (simState == IccCardConstants.State.PIN_REQUIRED) {
76            mode = SecurityMode.SimPin;
77        } else if (simState == IccCardConstants.State.PUK_REQUIRED
78                && mLockPatternUtils.isPukUnlockScreenEnable()) {
79            mode = SecurityMode.SimPuk;
80        } else {
81            final int security = mLockPatternUtils.getKeyguardStoredPasswordQuality();
82            switch (security) {
83                case DevicePolicyManager.PASSWORD_QUALITY_NUMERIC:
84                case DevicePolicyManager.PASSWORD_QUALITY_ALPHABETIC:
85                case DevicePolicyManager.PASSWORD_QUALITY_ALPHANUMERIC:
86                case DevicePolicyManager.PASSWORD_QUALITY_COMPLEX:
87                    mode = mLockPatternUtils.isLockPasswordEnabled() ?
88                            SecurityMode.Password : SecurityMode.None;
89                    break;
90
91                case DevicePolicyManager.PASSWORD_QUALITY_SOMETHING:
92                case DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED:
93                    if (mLockPatternUtils.isLockPatternEnabled()) {
94                        mode = mLockPatternUtils.isPermanentlyLocked() ?
95                            SecurityMode.Account : SecurityMode.Pattern;
96                    }
97                    break;
98
99                default:
100                    throw new IllegalStateException("Unknown unlock mode:" + mode);
101            }
102        }
103        return mode;
104    }
105
106    /**
107     * Some unlock methods can have an alternate, such as biometric unlocks (e.g. face unlock).
108     * This function decides if an alternate unlock is available and returns it. Otherwise,
109     * returns @param mode.
110     *
111     * @param mode the mode we want the alternate for
112     * @return alternate or the given mode
113     */
114    SecurityMode getAlternateFor(SecurityMode mode) {
115        if (isBiometricUnlockEnabled() && !isBiometricUnlockSuppressed()
116                && (mode == SecurityMode.Password || mode == SecurityMode.Pattern)) {
117            return SecurityMode.Biometric;
118        }
119        return mode; // no alternate, return what was given
120    }
121
122    /**
123     * Some unlock methods can have a backup which gives the user another way to get into
124     * the device. This is currently only supported for Biometric and Pattern unlock.
125     *
126     * @return backup method or current security mode
127     */
128    SecurityMode getBackupSecurityMode() {
129        SecurityMode mode = getSecurityMode();
130
131        // Note that getAlternateFor() cannot be called here because we want to get the backup for
132        // biometric unlock even if it's suppressed; it just has to be enabled.
133        if (isBiometricUnlockEnabled()
134                && (mode == SecurityMode.Password || mode == SecurityMode.Pattern)) {
135            mode = SecurityMode.Biometric;
136        }
137        switch(mode) {
138            case Biometric:
139                return getSecurityMode();
140            case Pattern:
141                return SecurityMode.Account;
142        }
143        return mode; // no backup, return current security mode
144    }
145}
146