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author | Jeff Sharkey <jsharkey@android.com> | 2016-10-07 14:00:46 -0700 |
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committer | Jessica Wagantall <jwagantall@cyngn.com> | 2016-11-10 12:29:00 -0800 |
commit | b9f6359f0a771f01ccfdbfa0c7efc1622db041c5 (patch) | |
tree | b3c187c9cc599d22e77bcb14e37ecc25c9843707 /src/com/android | |
parent | 8901501239ce7d7f9409d9910ecd40aa78770b62 (diff) | |
download | android_packages_providers_DownloadProvider-stable/cm-13.0-ZNH2K.tar.gz android_packages_providers_DownloadProvider-stable/cm-13.0-ZNH2K.tar.bz2 android_packages_providers_DownloadProvider-stable/cm-13.0-ZNH2K.zip |
Enforce calling identity before clearing.stable/cm-13.0-ZNH2K
When opening a downloaded file, enforce that the caller can actually
see the requested download before clearing their identity to read
internal columns.
However, this means that we can no longer return the "my_downloads"
paths: if those Uris were shared beyond the app that requested the
download, access would be denied. Instead, we need to switch to
using "all_downloads" Uris so that permission grants can be issued
to third-party viewer apps.
Since an app requesting a download doesn't normally have permission
to "all_downloads" paths, we issue narrow grants toward the owner of
each download, both at device boot and when new downloads are
started.
CYNGNOS-3303
Bug: 30537115, 30945409
Change-Id: If944aada020878a91c363963728d0da9f6fae3ea
(cherry picked from commit 7c1af8c62c8bdf6e8de5a00c1927daf9fd9c03d1)
Diffstat (limited to 'src/com/android')
-rw-r--r-- | src/com/android/providers/downloads/DownloadProvider.java | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/src/com/android/providers/downloads/DownloadProvider.java b/src/com/android/providers/downloads/DownloadProvider.java index d9acc789..ef64e5e9 100644 --- a/src/com/android/providers/downloads/DownloadProvider.java +++ b/src/com/android/providers/downloads/DownloadProvider.java @@ -462,6 +462,19 @@ public final class DownloadProvider extends ContentProvider { if (appInfo != null) { mDefContainerUid = appInfo.uid; } + + // Grant access permissions for all known downloads to the owning apps + final SQLiteDatabase db = mOpenHelper.getReadableDatabase(); + final Cursor cursor = db.query(DB_TABLE, new String[] { + Downloads.Impl._ID, Constants.UID }, null, null, null, null, null); + try { + while (cursor.moveToNext()) { + grantAllDownloadsPermission(cursor.getLong(0), cursor.getInt(1)); + } + } finally { + cursor.close(); + } + // start the DownloadService class. don't wait for the 1st download to be issued. // saves us by getting some initialization code in DownloadService out of the way. Context context = getContext(); @@ -687,6 +700,7 @@ public final class DownloadProvider extends ContentProvider { } insertRequestHeaders(db, rowID, values); + grantAllDownloadsPermission(rowID, Binder.getCallingUid()); notifyContentChanged(uri, match); // Always start service to handle notifications and/or scanning @@ -1193,6 +1207,7 @@ public final class DownloadProvider extends ContentProvider { try { while (cursor.moveToNext()) { final long id = cursor.getLong(0); + revokeAllDownloadsPermission(id); DownloadStorageProvider.onDownloadProviderDelete(getContext(), id); final String path = cursor.getString(1); @@ -1413,4 +1428,20 @@ public final class DownloadProvider extends ContentProvider { to.put(key, defaultValue); } } + + private void grantAllDownloadsPermission(long id, int uid) { + final String[] packageNames = getContext().getPackageManager().getPackagesForUid(uid); + if (packageNames == null || packageNames.length == 0) return; + + // We only need to grant to the first package, since the + // platform internally tracks based on UIDs + final Uri uri = ContentUris.withAppendedId(Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, id); + getContext().grantUriPermission(packageNames[0], uri, + Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION); + } + + private void revokeAllDownloadsPermission(long id) { + final Uri uri = ContentUris.withAppendedId(Downloads.Impl.ALL_DOWNLOADS_CONTENT_URI, id); + getContext().revokeUriPermission(uri, ~0); + } } |