diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java
index fbda90775..016651c3b 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpHelper.java
@@ -18,23 +18,15 @@
package org.sufficientlysecure.keychain.pgp;
-import android.content.Context;
-import android.content.pm.PackageInfo;
-import android.content.pm.PackageManager.NameNotFoundException;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
import android.support.annotation.NonNull;
import android.text.TextUtils;
import org.sufficientlysecure.keychain.Constants;
-import org.sufficientlysecure.keychain.R;
import org.sufficientlysecure.keychain.util.Log;
-import org.sufficientlysecure.keychain.util.Preferences;
-
-import java.io.File;
-import java.io.IOException;
-import java.io.RandomAccessFile;
-import java.security.SecureRandom;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
public class PgpHelper {
@@ -50,35 +42,6 @@ public class PgpHelper {
".*?(-----BEGIN PGP PUBLIC KEY BLOCK-----.*?-----END PGP PUBLIC KEY BLOCK-----).*",
Pattern.DOTALL);
- /**
- * Deletes file securely by overwriting it with random data before deleting it.
- *
- * TODO: Does this really help on flash storage?
- *
- * @throws IOException
- */
- public static void deleteFileSecurely(Context context, Progressable progressable, File file)
- throws IOException {
- long length = file.length();
- SecureRandom random = new SecureRandom();
- RandomAccessFile raf = new RandomAccessFile(file, "rws");
- raf.seek(0);
- raf.getFilePointer();
- byte[] data = new byte[1 << 16];
- int pos = 0;
- String msg = context.getString(R.string.progress_deleting_securely, file.getName());
- while (pos < length) {
- if (progressable != null) {
- progressable.setProgress(msg, (int) (100 * pos / length), 100);
- }
- random.nextBytes(data);
- raf.write(data);
- pos += data.length;
- }
- raf.close();
- file.delete();
- }
-
/**
* Fixing broken PGP MESSAGE Strings coming from GMail/AOSP Mail
*/
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptListFragment.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptListFragment.java
index c45a641e0..000de6e40 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptListFragment.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/DecryptListFragment.java
@@ -800,33 +800,18 @@ public class DecryptListFragment
// we can only ever delete a file once, if we got this far either it's gone or it will never work
mCanDelete = false;
- if ("file".equals(uri.getScheme())) {
- File file = new File(uri.getPath());
- if (file.delete()) {
+ try {
+ int deleted = FileHelper.deleteFileSecurely(activity, uri);
+ if (deleted > 0) {
Notify.create(activity, R.string.file_delete_ok, Style.OK).show();
} else {
Notify.create(activity, R.string.file_delete_none, Style.WARN).show();
}
- return;
+ } catch (Exception e) {
+ Log.e(Constants.TAG, "exception deleting file", e);
+ Notify.create(activity, R.string.file_delete_exception, Style.ERROR).show();
}
- if ("content".equals(uri.getScheme())) {
- try {
- int deleted = activity.getContentResolver().delete(uri, null, null);
- if (deleted > 0) {
- Notify.create(activity, R.string.file_delete_ok, Style.OK).show();
- } else {
- Notify.create(activity, R.string.file_delete_none, Style.WARN).show();
- }
- } catch (Exception e) {
- Log.e(Constants.TAG, "exception deleting file", e);
- Notify.create(activity, R.string.file_delete_exception, Style.ERROR).show();
- }
- return;
- }
-
- Notify.create(activity, R.string.file_delete_exception, Style.ERROR).show();
-
}
public class DecryptFilesAdapter extends RecyclerView.Adapter {
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/FileHelper.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/FileHelper.java
index 7345faad9..bae119700 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/FileHelper.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/FileHelper.java
@@ -25,7 +25,9 @@ import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
+import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
+import java.security.SecureRandom;
import java.text.DecimalFormat;
import android.annotation.TargetApi;
@@ -33,7 +35,6 @@ import android.content.ActivityNotFoundException;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
-import android.content.res.AssetFileDescriptor;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.Point;
@@ -41,20 +42,13 @@ import android.net.Uri;
import android.os.Build;
import android.os.Build.VERSION_CODES;
import android.os.Environment;
-import android.os.ParcelFileDescriptor;
import android.provider.DocumentsContract;
import android.provider.OpenableColumns;
import android.support.v4.app.Fragment;
-import android.system.ErrnoException;
-import android.system.Os;
-import android.system.StructStat;
import android.widget.Toast;
-import org.sufficientlysecure.keychain.Constants;
import org.sufficientlysecure.keychain.R;
-import static android.system.OsConstants.S_IROTH;
-
/** This class offers a number of helper functions for saving documents.
*
* There are three entry points here: openDocument, saveDocument and
@@ -167,6 +161,14 @@ public class FileHelper {
}
public static long getFileSize(Context context, Uri uri, long def) {
+ if ("file".equals(uri.getScheme())) {
+ long size = new File(uri.getPath()).length();
+ if (size == 0) {
+ size = def;
+ }
+ return size;
+ }
+
long size = def;
try {
Cursor cursor = context.getContentResolver().query(uri, new String[]{OpenableColumns.SIZE}, null, null, null);
@@ -261,6 +263,44 @@ public class FileHelper {
}
}
+ /**
+ * Deletes data at a URI securely by overwriting it with random data
+ * before deleting it. This method is fail-fast - if we can't securely
+ * delete the file, we don't delete it at all.
+ */
+ public static int deleteFileSecurely(Context context, Uri uri)
+ throws IOException {
+
+ ContentResolver resolver = context.getContentResolver();
+ long lengthLeft = FileHelper.getFileSize(context, uri);
+
+ if (lengthLeft == -1) {
+ throw new IOException("Error opening file!");
+ }
+
+ SecureRandom random = new SecureRandom();
+ byte[] randomData = new byte[1024];
+
+ OutputStream out = resolver.openOutputStream(uri, "w");
+ if (out == null) {
+ throw new IOException("Error opening file!");
+ }
+ out = new BufferedOutputStream(out);
+ while (lengthLeft > 0) {
+ random.nextBytes(randomData);
+ out.write(randomData, 0, lengthLeft > randomData.length ? randomData.length : (int) lengthLeft);
+ lengthLeft -= randomData.length;
+ }
+ out.close();
+
+ if ("file".equals(uri.getScheme())) {
+ return new File(uri.getPath()).delete() ? 1 : 0;
+ } else {
+ return resolver.delete(uri, null, null);
+ }
+
+ }
+
/** Checks if external storage is mounted if file is located on external storage. */
public static boolean isStorageMounted(String file) {
if (file.startsWith(Environment.getExternalStorageDirectory().getAbsolutePath())) {