Grant only the requested permissions

If an app requests a permission in a group we were auto granting it all
permissions from the group declared as used by the app. The intended
behavior is that we grant only the requested permission and requesting
a permission from a group where a permission is already granted results
in an auto-grant. The intended behavior was to prevent coding around
permission groups which a volatile by design. Now if apps target SDK
above M we provide the intended behavior, otherwise for apps targeting
M we provide an unchenged behavior.

bug:28347872

Change-Id: I493714b2c2581340b01b12ce6fedf80f9d3deec5

2 files changed, 59 insertions, 9 deletions

diff --git a/src/com/android/packageinstaller/permission/ui/GrantPermissionsActivity.java b/src/com/android/packageinstaller/permission/ui/GrantPermissionsActivity.java
index 78d33d23..807d3a3b 100644
--- a/src/com/android/packageinstaller/permission/ui/GrantPermissionsActivity.java
+++ b/src/com/android/packageinstaller/permission/ui/GrantPermissionsActivity.java
@@ -29,7 +29,6 @@ import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.graphics.Typeface;
 import android.graphics.drawable.Icon;
-import android.hardware.camera2.utils.ArrayUtils;
 import android.os.Build;
 import android.os.Bundle;
 import android.text.SpannableString;
@@ -47,6 +46,7 @@ import com.android.packageinstaller.permission.model.AppPermissionGroup;
 import com.android.packageinstaller.permission.model.AppPermissions;
 import com.android.packageinstaller.permission.model.Permission;
 import com.android.packageinstaller.permission.ui.handheld.GrantPermissionsViewHandlerImpl;
+import com.android.packageinstaller.permission.utils.ArrayUtils;
 import com.android.packageinstaller.permission.utils.SafetyNetLogger;
 
 import java.util.ArrayList;
@@ -147,24 +147,36 @@ public class GrantPermissionsActivity extends OverlayTouchActivity
                 switch (permissionPolicy) {
                     case DevicePolicyManager.PERMISSION_POLICY_AUTO_GRANT: {
                         if (!group.areRuntimePermissionsGranted()) {
-                            group.grantRuntimePermissions(false);
+                            group.grantRuntimePermissions(false, computeAffectedPermissions(
+                                    callingPackageInfo, requestedPermission));
                         }
                         group.setPolicyFixed();
                     } break;
 
                     case DevicePolicyManager.PERMISSION_POLICY_AUTO_DENY: {
                         if (group.areRuntimePermissionsGranted()) {
-                            group.revokeRuntimePermissions(false);
+                            group.revokeRuntimePermissions(false, computeAffectedPermissions(
+                                    callingPackageInfo, requestedPermission));
                         }
                         group.setPolicyFixed();
                     } break;
 
                     default: {
                         if (!group.areRuntimePermissionsGranted()) {
-                            mRequestGrantPermissionGroups.put(group.getName(),
-                                    new GroupState(group));
+                            GroupState state = mRequestGrantPermissionGroups.get(group.getName());
+                            if (state == null) {
+                                state = new GroupState(group);
+                                mRequestGrantPermissionGroups.put(group.getName(), state);
+                            }
+                            String affectedPermission = computeAffectedPermission(
+                                    callingPackageInfo, requestedPermission);
+                            if (affectedPermission != null) {
+                                state.affectedPermissions = ArrayUtils.appendString(
+                                        state.affectedPermissions, affectedPermission);
+                            }
                         } else {
-                            group.grantRuntimePermissions(false);
+                            group.grantRuntimePermissions(false, computeAffectedPermissions(
+                                    callingPackageInfo, requestedPermission));
                             updateGrantResults(group);
                         }
                     } break;
@@ -271,10 +283,12 @@ public class GrantPermissionsActivity extends OverlayTouchActivity
         GroupState groupState = mRequestGrantPermissionGroups.get(name);
         if (groupState.mGroup != null) {
             if (granted) {
-                groupState.mGroup.grantRuntimePermissions(doNotAskAgain);
+                groupState.mGroup.grantRuntimePermissions(doNotAskAgain,
+                        groupState.affectedPermissions);
                 groupState.mState = GroupState.STATE_ALLOWED;
             } else {
-                groupState.mGroup.revokeRuntimePermissions(doNotAskAgain);
+                groupState.mGroup.revokeRuntimePermissions(doNotAskAgain,
+                        groupState.affectedPermissions);
                 groupState.mState = GroupState.STATE_DENIED;
             }
             updateGrantResults(groupState.mGroup);
@@ -286,7 +300,7 @@ public class GrantPermissionsActivity extends OverlayTouchActivity
 
     private void updateGrantResults(AppPermissionGroup group) {
         for (Permission permission : group.getPermissions()) {
-            final int index = ArrayUtils.getArrayIndex(
+            final int index = ArrayUtils.indexOf(
                     mRequestedPermissions, permission.getName());
             if (index >= 0) {
                 mGrantResults[index] = permission.isGranted() ? PackageManager.PERMISSION_GRANTED
@@ -402,6 +416,23 @@ public class GrantPermissionsActivity extends OverlayTouchActivity
         SafetyNetLogger.logPermissionsRequested(mAppPermissions.getPackageInfo(), groups);
     }
 
+    private static String[] computeAffectedPermissions(PackageInfo callingPackageInfo,
+            String permission) {
+        String affectedPermission = computeAffectedPermission(callingPackageInfo, permission);
+        if (affectedPermission != null) {
+            return new String[] {permission};
+        }
+        return null;
+    }
+
+    private static String computeAffectedPermission(PackageInfo callingPackageInfo,
+            String permission) {
+        if (callingPackageInfo.applicationInfo.targetSdkVersion > Build.VERSION_CODES.M) {
+            return permission;
+        }
+        return null;
+    }
+
     private static final class GroupState {
         static final int STATE_UNKNOWN = 0;
         static final int STATE_ALLOWED = 1;
@@ -409,6 +440,7 @@ public class GrantPermissionsActivity extends OverlayTouchActivity
 
         final AppPermissionGroup mGroup;
         int mState = STATE_UNKNOWN;
+        String[] affectedPermissions;
 
         GroupState(AppPermissionGroup group) {
             mGroup = group;
diff --git a/src/com/android/packageinstaller/permission/utils/ArrayUtils.java b/src/com/android/packageinstaller/permission/utils/ArrayUtils.java
index 4b7a3947..2af641bc 100644
--- a/src/com/android/packageinstaller/permission/utils/ArrayUtils.java
+++ b/src/com/android/packageinstaller/permission/utils/ArrayUtils.java
@@ -16,6 +16,8 @@
 
 package com.android.packageinstaller.permission.utils;
 
+import android.text.TextUtils;
+
 import java.util.Objects;
 
 public final class ArrayUtils {
@@ -42,4 +44,20 @@ public final class ArrayUtils {
         }
         return -1;
     }
+
+    public static String[] appendString(String[] cur, String val) {
+        if (cur == null) {
+            return new String[] { val };
+        }
+        final int N = cur.length;
+        for (int i = 0; i < N; i++) {
+            if (TextUtils.equals(cur[i], val)) {
+                return cur;
+            }
+        }
+        String[] ret = new String[N + 1];
+        System.arraycopy(cur, 0, ret, 0, N);
+        ret[N] = val;
+        return ret;
+    }
 }