diff options
Diffstat (limited to 'OpenKeychain/src/main/java/org')
| -rw-r--r-- | OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/TemporaryStorageProvider.java | 61 |
1 files changed, 46 insertions, 15 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/TemporaryStorageProvider.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/TemporaryStorageProvider.java index cbb243fad..7e9b24989 100644 --- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/TemporaryStorageProvider.java +++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/TemporaryStorageProvider.java @@ -19,23 +19,15 @@ package org.sufficientlysecure.keychain.provider; -import java.io.File; -import java.io.FileNotFoundException; -import java.io.IOException; -import java.util.UUID; - import android.content.ClipDescription; import android.content.ContentProvider; import android.content.ContentValues; import android.content.Context; -import android.content.res.AssetFileDescriptor; import android.database.Cursor; import android.database.MatrixCursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.net.Uri; -import android.os.Bundle; -import android.os.CancellationSignal; import android.os.ParcelFileDescriptor; import android.provider.OpenableColumns; @@ -43,6 +35,30 @@ import org.sufficientlysecure.keychain.Constants; import org.sufficientlysecure.keychain.util.DatabaseUtil; import org.sufficientlysecure.keychain.util.Log; +import java.io.File; +import java.io.FileNotFoundException; +import java.io.IOException; +import java.util.UUID; + +/** + * TemporaryStorageProvider stores decrypted files inside the app's cache directory previously to + * sharing them with other applications. + * + * Security: + * - It is writable by OpenKeychain only (see Manifest), but exported for reading files + * - It uses UUIDs as identifiers which makes predicting files from outside impossible + * - Querying a number of files is not allowed, only querying single files + * -> You can only open a file if you know the Uri containing the precise UUID, this Uri is only + * revealed when the user shares a decrypted file with another app. + * + * Why is support lib's FileProvider not used? + * Because granting Uri permissions temporarily does not work correctly. See + * - https://code.google.com/p/android/issues/detail?id=76683 + * - https://github.com/nmr8acme/FileProvider-permission-bug + * - http://stackoverflow.com/q/24467696 + * - http://stackoverflow.com/q/18249007 + * - Comments at http://www.blogc.at/2014/03/23/share-private-files-with-other-apps-fileprovider/ + */ public class TemporaryStorageProvider extends ContentProvider { private static final String DB_NAME = "tempstorage.db"; @@ -143,6 +159,10 @@ public class TemporaryStorageProvider extends ContentProvider { @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { + if (uri.getLastPathSegment() == null) { + throw new SecurityException("Listing temporary files is not allowed, only querying single files."); + } + File file; try { file = getFile(uri); @@ -153,9 +173,15 @@ public class TemporaryStorageProvider extends ContentProvider { new String[]{uri.getLastPathSegment()}, null, null, null); if (fileName != null) { if (fileName.moveToNext()) { - MatrixCursor cursor = - new MatrixCursor(new String[]{OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE, "_data"}); - cursor.newRow().add(fileName.getString(0)).add(file.length()).add(file.getAbsolutePath()); + MatrixCursor cursor = new MatrixCursor(new String[]{ + OpenableColumns.DISPLAY_NAME, + OpenableColumns.SIZE, + "_data" + }); + cursor.newRow() + .add(fileName.getString(0)) + .add(file.length()) + .add(file.getAbsolutePath()); fileName.close(); return cursor; } @@ -167,8 +193,8 @@ public class TemporaryStorageProvider extends ContentProvider { @Override public String getType(Uri uri) { Cursor cursor = db.getReadableDatabase().query(TABLE_FILES, - new String[]{ COLUMN_TYPE }, COLUMN_ID + "=?", - new String[]{ uri.getLastPathSegment() }, null, null, null); + new String[]{COLUMN_TYPE}, COLUMN_ID + "=?", + new String[]{uri.getLastPathSegment()}, null, null, null); if (cursor != null) { try { if (cursor.moveToNext()) { @@ -187,7 +213,7 @@ public class TemporaryStorageProvider extends ContentProvider { public String[] getStreamTypes(Uri uri, String mimeTypeFilter) { String type = getType(uri); if (ClipDescription.compareMimeTypes(type, mimeTypeFilter)) { - return new String[] { type }; + return new String[]{type}; } return null; } @@ -200,9 +226,14 @@ public class TemporaryStorageProvider extends ContentProvider { String uuid = UUID.randomUUID().toString(); values.put(COLUMN_ID, uuid); int insert = (int) db.getWritableDatabase().insert(TABLE_FILES, null, values); + if (insert == -1) { + Log.e(Constants.TAG, "Insert failed!"); + return null; + } try { getFile(uuid).createNewFile(); } catch (IOException e) { + Log.e(Constants.TAG, "File creation failed!"); return null; } return Uri.withAppendedPath(BASE_URI, uuid); @@ -238,7 +269,7 @@ public class TemporaryStorageProvider extends ContentProvider { throw new UnsupportedOperationException("Update supported only for plain uri!"); } return db.getWritableDatabase().update(TABLE_FILES, values, - COLUMN_ID + " = ?", new String[]{ uri.getLastPathSegment() }); + COLUMN_ID + " = ?", new String[]{uri.getLastPathSegment()}); } @Override |