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Commit b763e342 authored by Dianne Hackborn's avatar Dianne Hackborn
Browse files

Improve protection against malicious admins. 

- 2 second timeout until we give up on displaying a message,
  keeping us within the 5 second activity launch block time.
- Restart the activity launch block when we show the dialog.
- Use app ops to prevent the app of the currently displayed
  admin from putting windows on top while the settings screen
  is running.

Change-Id: I631e8896ec7539c2de3ff36f183e67e36bcc37ca
parent 7e974f4c

src/com/android/settings/DeviceAdminAdd.java

+65 −15
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 


package com.android.settings;



import android.app.AppOpsManager;

import org.xmlpull.v1.XmlPullParserException;



import android.app.Activity;
@@ -51,7 +52,6 @@ import android.widget.TextView; 


import java.io.IOException;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.List;



public class DeviceAdminAdd extends Activity {
@@ -66,6 +66,7 @@ public class DeviceAdminAdd extends Activity { 
    Handler mHandler;



    DevicePolicyManager mDPM;

    AppOpsManager mAppOps;

    DeviceAdminInfo mDeviceAdmin;

    CharSequence mAddMsgText;
@@ -85,6 +86,9 @@ public class DeviceAdminAdd extends Activity { 


    boolean mAdding;

    boolean mRefreshing;

    boolean mWaitingForRemoveMsg;

    int mCurSysAppOpMode;

    int mCurToastAppOpMode;



    @Override

    protected void onCreate(Bundle icicle) {
@@ -93,6 +97,7 @@ public class DeviceAdminAdd extends Activity { 
        mHandler = new Handler(getMainLooper());



        mDPM = (DevicePolicyManager)getSystemService(Context.DEVICE_POLICY_SERVICE);

        mAppOps = (AppOpsManager)getSystemService(Context.APP_OPS_SERVICE);



        if ((getIntent().getFlags()&Intent.FLAG_ACTIVITY_NEW_TASK) != 0) {

            Log.w(TAG, "Cannot start ADD_DEVICE_ADMIN as a new task");
@@ -235,13 +240,14 @@ public class DeviceAdminAdd extends Activity { 
                        }

                    }

                    finish();

                } else {

                } else if (!mWaitingForRemoveMsg) {

                    try {

                        // Don't allow the admin to put a dialog up in front

                        // of us while we interact with the user.

                        ActivityManagerNative.getDefault().stopAppSwitches();

                    } catch (RemoteException e) {

                    }

                    mWaitingForRemoveMsg = true;

                    mDPM.getRemoveWarning(mDeviceAdmin.getComponent(),

                            new RemoteCallback(mHandler) {

                        @Override
@@ -250,6 +256,25 @@ public class DeviceAdminAdd extends Activity { 
                                    ? bundle.getCharSequence(

                                            DeviceAdminReceiver.EXTRA_DISABLE_WARNING)

                                    : null;

                            continueRemoveAction(msg);

                        }

                    });

                    // Don't want to wait too long.

                    getWindow().getDecorView().getHandler().postDelayed(new Runnable() {

                        @Override public void run() {

                            continueRemoveAction(null);

                        }

                    }, 2*1000);

                }

            }

        });

    }



    void continueRemoveAction(CharSequence msg) {

        if (!mWaitingForRemoveMsg) {

            return;

        }

        mWaitingForRemoveMsg = false;

        if (msg == null) {

            try {

                ActivityManagerNative.getDefault().resumeAppSwitches();
@@ -258,22 +283,43 @@ public class DeviceAdminAdd extends Activity { 
            mDPM.removeActiveAdmin(mDeviceAdmin.getComponent());

            finish();

        } else {

            try {

                // Continue preventing anything from coming in front.

                ActivityManagerNative.getDefault().stopAppSwitches();

            } catch (RemoteException e) {

            }

            Bundle args = new Bundle();

            args.putCharSequence(

                    DeviceAdminReceiver.EXTRA_DISABLE_WARNING, msg);

            showDialog(DIALOG_WARNING, args);

        }

    }

                    });

                }

            }

        });

    }



    @Override

    protected void onResume() {

        super.onResume();

        updateInterface();

        // As long as we are running, don't let this admin overlay stuff on top of the screen.

        final int uid = mDeviceAdmin.getActivityInfo().applicationInfo.uid;

        final String pkg = mDeviceAdmin.getActivityInfo().applicationInfo.packageName;

        mCurSysAppOpMode = mAppOps.checkOp(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, uid, pkg);

        mCurToastAppOpMode = mAppOps.checkOp(AppOpsManager.OP_TOAST_WINDOW, uid, pkg);

        mAppOps.setMode(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, uid, pkg, AppOpsManager.MODE_IGNORED);

        mAppOps.setMode(AppOpsManager.OP_TOAST_WINDOW, uid, pkg, AppOpsManager.MODE_IGNORED);

    }



    @Override

    protected void onPause() {

        super.onPause();

        // As long as we are running, don't let this admin overlay stuff on top of the screen.

        final int uid = mDeviceAdmin.getActivityInfo().applicationInfo.uid;

        final String pkg = mDeviceAdmin.getActivityInfo().applicationInfo.packageName;

        mAppOps.setMode(AppOpsManager.OP_SYSTEM_ALERT_WINDOW, uid, pkg, mCurSysAppOpMode);

        mAppOps.setMode(AppOpsManager.OP_TOAST_WINDOW, uid, pkg, mCurToastAppOpMode);

        try {

            ActivityManagerNative.getDefault().resumeAppSwitches();

        } catch (RemoteException e) {

        }

    }



    @Override
@@ -287,6 +333,10 @@ public class DeviceAdminAdd extends Activity { 
                builder.setPositiveButton(R.string.dlg_ok,

                        new DialogInterface.OnClickListener() {

                    public void onClick(DialogInterface dialog, int which) {

                        try {

                            ActivityManagerNative.getDefault().resumeAppSwitches();

                        } catch (RemoteException e) {

                        }

                        mDPM.removeActiveAdmin(mDeviceAdmin.getComponent());

                        finish();

                    }