DO NOT MERGE Redact Account info from getCurrentSyncs

BUG:26094635
If the caller to ContentResolver#getCurrentSyncs does not hold the
GET_ACCOUNTS permission, return a SyncInfo object that does not
contain any Account information.

Change-Id: I5628ebe1f56c8e3f784aaf1b3281e6b829d19314
(cherry picked from commit b63057e698)

core/java/android/content/SyncInfo.java

@@ -25,6 +25,13 @@ import android.os.Parcelable.Creator;
  * Information about the sync operation that is currently underway.
  */
 public class SyncInfo implements Parcelable {
+    /**
+     * Used when the caller receiving this object doesn't have permission to access the accounts
+     * on device.
+     * @See Manifest.permission.GET_ACCOUNTS
+     */
+    private static final Account REDACTED_ACCOUNT = new Account("*****", "*****");
+
     /** @hide */
     public final int authorityId;
 
@@ -45,6 +52,17 @@ public class SyncInfo implements Parcelable {
      */
     public final long startTime;
 
+    /**
+     * Creates a SyncInfo object with an unusable Account. Used when the caller receiving this
+     * object doesn't have access to the accounts on the device.
+     * @See Manifest.permission.GET_ACCOUNTS
+     * @hide
+     */
+    public static SyncInfo createAccountRedacted(
+        int authorityId, String authority, long startTime) {
+            return new SyncInfo(authorityId, REDACTED_ACCOUNT, authority, startTime);
+    }
+
     /** @hide */
     public SyncInfo(int authorityId, Account account, String authority,
             long startTime) {

services/java/com/android/server/content/ContentService.java

@@ -28,6 +28,7 @@ import android.content.SyncAdapterType;
 import android.content.SyncInfo;
 import android.content.SyncRequest;
 import android.content.SyncStatusInfo;
+import android.content.pm.PackageManager;
 import android.database.IContentObserver;
 import android.database.sqlite.SQLiteException;
 import android.net.Uri;
@@ -654,13 +655,26 @@ public final class ContentService extends IContentService.Stub {
     }
 
     public List<SyncInfo> getCurrentSyncs() {
+        return getCurrentSyncsAsUser(UserHandle.getCallingUserId());
+    }
+
+    /**
+     * If the user id supplied is different to the calling user, the caller must hold the
+     * INTERACT_ACROSS_USERS_FULL permission.
+     */
+    public List<SyncInfo> getCurrentSyncsAsUser(int userId) {
+        enforceCrossUserPermission(userId,
+                "no permission to read the sync settings for user " + userId);
         mContext.enforceCallingOrSelfPermission(Manifest.permission.READ_SYNC_STATS,
                 "no permission to read the sync stats");
 
-        int userId = UserHandle.getCallingUserId();
+        final boolean canAccessAccounts =
+            mContext.checkCallingOrSelfPermission(Manifest.permission.GET_ACCOUNTS)
+                == PackageManager.PERMISSION_GRANTED;
         long identityToken = clearCallingIdentity();
         try {
-            return getSyncManager().getSyncStorageEngine().getCurrentSyncsCopy(userId);
+            return getSyncManager().getSyncStorageEngine()
+                .getCurrentSyncsCopy(userId, canAccessAccounts);
         } finally {
             restoreCallingIdentity(identityToken);
         }
@@ -734,6 +748,21 @@ public final class ContentService extends IContentService.Stub {
         return service;
     }
 
+    /**
+     * Checks if the request is from the system or an app that has INTERACT_ACROSS_USERS_FULL
+     * permission, if the userHandle is not for the caller.
+     *
+     * @param userHandle the user handle of the user we want to act on behalf of.
+     * @param message the message to log on security exception.
+     */
+    private void enforceCrossUserPermission(int userHandle, String message) {
+        final int callingUser = UserHandle.getCallingUserId();
+        if (callingUser != userHandle) {
+            mContext.enforceCallingOrSelfPermission(
+                    Manifest.permission.INTERACT_ACROSS_USERS_FULL, message);
+        }
+    }
+
     /**
      * Hide this class since it is not part of api,
      * but current unittest framework requires it to be public

services/java/com/android/server/content/SyncStorageEngine.java

@@ -1306,15 +1306,23 @@ public class SyncStorageEngine extends Handler {
     }
 
     /**
-     * @return a copy of the current syncs data structure. Will not return
-     * null.
+     * @param userId Id of user to return current sync info.
+     * @param canAccessAccounts Determines whether to redact Account information from the result.
+     * @return a copy of the current syncs data structure. Will not return null.
      */
-    public List<SyncInfo> getCurrentSyncsCopy(int userId) {
+    public List<SyncInfo> getCurrentSyncsCopy(int userId, boolean canAccessAccounts) {
         synchronized (mAuthorities) {
             final List<SyncInfo> syncs = getCurrentSyncsLocked(userId);
             final List<SyncInfo> syncsCopy = new ArrayList<SyncInfo>();
             for (SyncInfo sync : syncs) {
-                syncsCopy.add(new SyncInfo(sync));
+                SyncInfo copy;
+                if (!canAccessAccounts) {
+                    copy = SyncInfo.createAccountRedacted(
+                        sync.authorityId, sync.authority, sync.startTime);
+                } else {
+                    copy = new SyncInfo(sync);
+                }
+                syncsCopy.add(copy);
             }
             return syncsCopy;
         }