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Commit d7eb72b9 authored by Sergey Nikolaienkov's avatar Sergey Nikolaienkov
Browse files

Permissions checks for CDM.associate() 

Bug: 209581046
Bug: 208307075
Test: atest CompanionDeviceManagerTest
Change-Id: Ieb3ae096ed6e87cabf5a86db4cf2b92308e50426
parent f7d3ea87

services/companion/java/com/android/server/companion/AssociationRequestsProcessor.java

+2 −2
Original line number Diff line number Diff line
@@ -20,7 +20,7 @@ import static com.android.internal.util.CollectionUtils.filter; 
import static com.android.internal.util.FunctionalUtils.uncheckExceptions;

import static com.android.server.companion.CompanionDeviceManagerService.DEBUG;

import static com.android.server.companion.CompanionDeviceManagerService.LOG_TAG;

import static com.android.server.companion.PermissionsUtils.enforceCallerPermissionsToRequest;

import static com.android.server.companion.PermissionsUtils.enforcePermissionsForAssociation;

import static com.android.server.companion.RolesUtils.isRoleHolder;



import static java.util.Objects.requireNonNull;
@@ -110,7 +110,7 @@ class AssociationRequestsProcessor { 
        }



        // 1. Enforce permissions and other requirements.

        enforceCallerPermissionsToRequest(mContext, request, packageName, userId);

        enforcePermissionsForAssociation(mContext, request, packageName, userId);

        mService.checkUsesFeature(packageName, userId);



        // 2. Check if association can be created without launching UI (i.e. CDM needs NEITHER

services/companion/java/com/android/server/companion/CompanionDeviceManagerService.java

+10 −8
Original line number Diff line number Diff line
@@ -39,7 +39,8 @@ import static com.android.internal.util.function.pooled.PooledLambda.obtainRunna 
import static com.android.server.companion.PermissionsUtils.checkCallerCanManageAssociationsForPackage;

import static com.android.server.companion.PermissionsUtils.checkCallerCanManageCompanionDevice;

import static com.android.server.companion.PermissionsUtils.enforceCallerCanInteractWithUserId;

import static com.android.server.companion.PermissionsUtils.enforceCallerCanManagerCompanionDevice;

import static com.android.server.companion.PermissionsUtils.enforceCallerCanManageAssociationsForPackage;

import static com.android.server.companion.PermissionsUtils.enforceCallerCanManageCompanionDevice;

import static com.android.server.companion.PermissionsUtils.enforceCallerIsSystemOr;

import static com.android.server.companion.RolesUtils.addRoleHolderForAssociation;

import static com.android.server.companion.RolesUtils.removeRoleHolderForAssociation;
@@ -401,15 +402,16 @@ public class CompanionDeviceManagerService extends SystemService { 
            Slog.i(LOG_TAG, "associate() "

                    + "request=" + request + ", "

                    + "package=u" + userId + "/" + packageName);

            enforceCallerCanManageAssociationsForPackage(getContext(), userId, packageName,

                    "create associations");



            mAssociationRequestsProcessor.process(request, packageName, userId, callback);

        }



        @Override

        public List<AssociationInfo> getAssociations(String packageName, int userId) {

            if (!checkCallerCanManageAssociationsForPackage(getContext(), userId, packageName)) {

                throw new SecurityException("Caller (uid=" + getCallingUid() + ") does not have "

                        + "permissions to get associations for u" + userId + "/" + packageName);

            }

            enforceCallerCanManageAssociationsForPackage(getContext(), userId, packageName,

                    "get associations");



            if (!checkCallerCanManageCompanionDevice(getContext())) {

                // If the caller neither is system nor holds MANAGE_COMPANION_DEVICES: it needs to
@@ -424,7 +426,7 @@ public class CompanionDeviceManagerService extends SystemService { 
        @Override

        public List<AssociationInfo> getAllAssociationsForUser(int userId) throws RemoteException {

            enforceCallerCanInteractWithUserId(getContext(), userId);

            enforceCallerCanManagerCompanionDevice(getContext(), "getAllAssociationsForUser");

            enforceCallerCanManageCompanionDevice(getContext(), "getAllAssociationsForUser");



            return new ArrayList<>(

                    CompanionDeviceManagerService.this.getAllAssociationsForUser(userId));
@@ -434,7 +436,7 @@ public class CompanionDeviceManagerService extends SystemService { 
        public void addOnAssociationsChangedListener(IOnAssociationsChangedListener listener,

                int userId) {

            enforceCallerCanInteractWithUserId(getContext(), userId);

            enforceCallerCanManagerCompanionDevice(getContext(),

            enforceCallerCanManageCompanionDevice(getContext(),

                    "addOnAssociationsChangedListener");



            //TODO: Implement.
@@ -621,7 +623,7 @@ public class CompanionDeviceManagerService extends SystemService { 
        public void onShellCommand(FileDescriptor in, FileDescriptor out, FileDescriptor err,

                String[] args, ShellCallback callback, ResultReceiver resultReceiver)

                throws RemoteException {

            enforceCallerCanManagerCompanionDevice(getContext(), "onShellCommand");

            enforceCallerCanManageCompanionDevice(getContext(), "onShellCommand");

            new CompanionDeviceShellCommand(CompanionDeviceManagerService.this)

                    .exec(this, in, out, err, args, callback, resultReceiver);

        }

services/companion/java/com/android/server/companion/PermissionsUtils.java

+39 −11
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ import static android.companion.AssociationRequest.DEVICE_PROFILE_APP_STREAMING; 
import static android.companion.AssociationRequest.DEVICE_PROFILE_AUTOMOTIVE_PROJECTION;

import static android.companion.AssociationRequest.DEVICE_PROFILE_WATCH;

import static android.content.pm.PackageManager.PERMISSION_GRANTED;

import static android.os.Binder.getCallingPid;

import static android.os.Binder.getCallingUid;

import static android.os.Process.SYSTEM_UID;

import static android.os.UserHandle.getCallingUserId;
@@ -37,11 +38,13 @@ import android.annotation.UserIdInt; 
import android.companion.AssociationRequest;

import android.companion.CompanionDeviceManager;

import android.content.Context;

import android.content.pm.PackageManagerInternal;

import android.os.RemoteException;

import android.os.ServiceManager;

import android.util.ArrayMap;



import com.android.internal.app.IAppOpsService;

import com.android.server.LocalServices;



import java.util.Map;
@@ -65,21 +68,19 @@ final class PermissionsUtils { 
        DEVICE_PROFILE_TO_PERMISSION = unmodifiableMap(map);

    }



    static void enforceCallerPermissionsToRequest(@NonNull Context context,

    static void enforcePermissionsForAssociation(@NonNull Context context,

            @NonNull AssociationRequest request, @NonNull String packageName,

            @UserIdInt int userId) {

        enforceCallerCanInteractWithUserId(context, userId);

        enforceCallerIsSystemOr(userId, packageName);



        enforceRequestDeviceProfilePermissions(context, request.getDeviceProfile());

        final int packageUid = getPackageUid(userId, packageName);

        enforceRequestDeviceProfilePermissions(context, request.getDeviceProfile(), packageUid);



        if (request.isSelfManaged()) {

            enforceRequestSelfManagedPermission(context);

            enforceRequestSelfManagedPermission(context, packageUid);

        }

    }



    static void enforceRequestDeviceProfilePermissions(

            @NonNull Context context, @Nullable String deviceProfile) {

            @NonNull Context context, @Nullable String deviceProfile, int packageUid) {

        // Device profile can be null.

        if (deviceProfile == null) return;
@@ -100,14 +101,15 @@ final class PermissionsUtils { 
        }



        final String permission = DEVICE_PROFILE_TO_PERMISSION.get(deviceProfile);

        if (context.checkCallingOrSelfPermission(permission) != PERMISSION_GRANTED) {

        if (context.checkPermission(permission, getCallingPid(), packageUid)

                != PERMISSION_GRANTED) {

            throw new SecurityException("Application must hold " + permission + " to associate "

                    + "with a device with " + deviceProfile + " profile.");

        }

    }



    static void enforceRequestSelfManagedPermission(@NonNull Context context) {

        if (context.checkCallingOrSelfPermission(REQUEST_COMPANION_SELF_MANAGED)

    static void enforceRequestSelfManagedPermission(@NonNull Context context, int packageUid) {

        if (context.checkPermission(REQUEST_COMPANION_SELF_MANAGED, getCallingPid(), packageUid)

                != PERMISSION_GRANTED) {

            throw new SecurityException("Application does not hold "

                    + REQUEST_COMPANION_SELF_MANAGED);
@@ -159,13 +161,34 @@ final class PermissionsUtils { 
        return context.checkCallingPermission(MANAGE_COMPANION_DEVICES) == PERMISSION_GRANTED;

    }



    static void enforceCallerCanManagerCompanionDevice(@NonNull Context context,

    static void enforceCallerCanManageCompanionDevice(@NonNull Context context,

            @Nullable String message) {

        if (getCallingUid() == SYSTEM_UID) return;



        context.enforceCallingPermission(MANAGE_COMPANION_DEVICES, message);

    }



    static void enforceCallerCanManageAssociationsForPackage(@NonNull Context context,

            @UserIdInt int userId, @NonNull String packageName,

            @Nullable String actionDescription) {

        if (checkCallerCanManageAssociationsForPackage(context, userId, packageName)) return;



        throw new SecurityException("Caller (uid=" + getCallingUid() + ") does not have "

                + "permissions to "

                + (actionDescription != null ? actionDescription : "manage associations")

                + " for u" + userId + "/" + packageName);

    }



    /**

     * Check if the caller is either:

     * <ul>

     * <li> the package itself

     * <li> the System ({@link android.os.Process#SYSTEM_UID})

     * <li> holds {@link Manifest.permission#MANAGE_COMPANION_DEVICES} and, if belongs to a

     * different user, also holds {@link Manifest.permission#INTERACT_ACROSS_USERS}.

     * </ul>

     * @return whether the caller is one of the above.

     */

    static boolean checkCallerCanManageAssociationsForPackage(@NonNull Context context,

            @UserIdInt int userId, @NonNull String packageName) {

        if (checkCallerIsSystemOr(userId, packageName)) return true;
@@ -184,6 +207,11 @@ final class PermissionsUtils { 
        }

    }



    private static int getPackageUid(@UserIdInt int userId, @NonNull String packageName) {

        return LocalServices.getService(PackageManagerInternal.class)

                .getPackageUid(packageName, 0, userId);

    }



    private static IAppOpsService getAppOpsService() {

        if (sAppOpsService == null) {

            synchronized (PermissionsUtils.class) {