allow to export imported keyfiles, closes https://github.com/PhilippC/keepass2android/issues/599

src/java/JavaFileStorage/app/src/main/AndroidManifest.xml

@@ -6,7 +6,7 @@
     android:versionName="1.0">
 
     <uses-sdk
-        android:minSdkVersion="8"
+        android:minSdkVersion="14"
         android:targetSdkVersion="14" />
 
     <uses-permission android:name="android.permission.GET_ACCOUNTS" />

src/keepass2android/Resources/values/strings.xml

@@ -56,6 +56,7 @@
   <string name="fingerprint_prefs">Biometric unlock</string>
 	<string name="import_db_prefs">Import database to internal folder</string>
 	<string name="import_keyfile_prefs">Import key file to internal folder</string>
+  <string name="export_keyfile_prefs">Export key file from internal folder</string>
 	<string name="keyboardswitch_prefs">Keyboard switching</string>
 	<string name="OnlyAvailableForLocalFiles">Only available for local files.</string>
 	<string name="FileIsInInternalDirectory">File is stored in internal directory.</string>
@@ -248,8 +249,10 @@
   <string name="saving_database">Saving database…</string>
 	<string name="exporting_database">Exporting database…</string>
 	<string name="export_database_successful">Database exported successfully!</string>
+  <string name="export_keyfile_successful">Key file exported successfully!</string>
   
-	<string name="space">Space</string>
+
+  <string name="space">Space</string>
   <string name="search_label">Search</string>
   <string name="show_password">Show password</string>
 	<string name="sort_menu">Sort by...</string>
@@ -784,6 +787,7 @@
 
 
   <string-array name="ChangeLog_1_08c">
+    <item>Updated Jsch to version 0.1.55</item>
     <item>No longer storing package names of Android apps in the URL field</item>
     <item>Improve locking behavior - no longer displaying biometric prompt immediately after unlocking</item>
     <item>Update OkHttp to support HTTP/2</item>

src/keepass2android/Resources/xml/preferences.xml

@@ -129,9 +129,15 @@
 			  android:title="@string/import_keyfile_prefs"
 	  />
 
+    <Preference
+      android:key="export_keyfile_prefs"
+      android:title="@string/export_keyfile_prefs"
+    />
 
 
-	</PreferenceScreen>
+
+
+  </PreferenceScreen>
 	
 
 	<PreferenceScreen

src/keepass2android/settings/DatabaseSettingsActivity.cs

@@ -17,6 +17,7 @@ This file is part of Keepass2Android, Copyright 2013 Philipp Crocoll. This file
 
 using System;
 using System.Globalization;
+using System.IO;
 using System.Linq;
 using System.Threading;
 using Android.App;
@@ -28,6 +29,7 @@ using Android.Preferences;
 using Android.Provider;
 using Android.Views.Autofill;
 using Java.IO;
+using KeePass.DataExchange;
 using KeePassLib.Cryptography.Cipher;
 using KeePassLib.Keys;
 using KeePassLib.Serialization;
@@ -36,11 +38,12 @@ using keepass2android.Io;
 using keepass2android.Utils;
 using KeePassLib;
 using KeePassLib.Cryptography.KeyDerivation;
+using KeePassLib.Interfaces;
 
 namespace keepass2android
 {
     //http://stackoverflow.com/a/27422401/292233
-    public class SettingsFragment : PreferenceFragment
+        public class SettingsFragment : PreferenceFragment
     {
 
 
@@ -131,7 +134,8 @@ namespace keepass2android
         private KeyboardSwitchPrefManager _switchPrefManager;
 		private Preference aesRounds, argon2parallelism, argon2rounds, argon2memory;
         
-	    void OnRememberKeyFileHistoryChanged(object sender, Preference.PreferenceChangeEventArgs eventArgs)
+
+        void OnRememberKeyFileHistoryChanged(object sender, Preference.PreferenceChangeEventArgs eventArgs)
         {
             if (!(bool)eventArgs.NewValue)
             {
@@ -631,13 +635,15 @@ namespace keepass2android
             var prefs = PreferenceManager.GetDefaultSharedPreferences(Activity);
             var rememberKeyfile = prefs.GetBoolean(GetString(Resource.String.keyfile_key), Resources.GetBoolean(Resource.Boolean.keyfile_default));
 
-            Preference importDb = FindPreference("import_keyfile_prefs");
+            Preference importKeyfile = FindPreference("import_keyfile_prefs");
-            importDb.Summary = "";
+            Preference exportKeyfile = FindPreference("export_keyfile_prefs");
+            importKeyfile.Summary = "";
 
             if (!rememberKeyfile)
             {
-                importDb.Summary = GetString(Resource.String.KeyfileMoveRequiresRememberKeyfile);
+                importKeyfile.Summary = GetString(Resource.String.KeyfileMoveRequiresRememberKeyfile);
-                importDb.Enabled = false;
+                importKeyfile.Enabled = false;
+                exportKeyfile.Enabled = false;
                 return;
             }
             CompositeKey masterKey = App.Kp2a.CurrentDb.KpDatabase.MasterKey;
@@ -646,23 +652,35 @@ namespace keepass2android
                 IOConnectionInfo iocKeyfile = ((KcpKeyFile)masterKey.GetUserKey(typeof(KcpKeyFile))).Ioc;
                 if (iocKeyfile.IsLocalFile() && IoUtil.IsInInternalDirectory(iocKeyfile.Path, Activity))
                 {
-                    importDb.Enabled = false;
+                    importKeyfile.Enabled = false;
-                    importDb.Summary = GetString(Resource.String.FileIsInInternalDirectory);
+                    exportKeyfile.Enabled = true;
+                    exportKeyfile.PreferenceClick += (sender, args) => { ExportKeyfileFromInternalFolder(); };
+                    importKeyfile.Summary = GetString(Resource.String.FileIsInInternalDirectory);
                 }
                 else
                 {
-                    importDb.Enabled = true;
+                    exportKeyfile.Enabled = false;
-                    importDb.PreferenceClick += (sender, args) => { MoveKeyfileToInternalFolder(); };
+                    importKeyfile.Enabled = true;
+                    importKeyfile.PreferenceClick += (sender, args) => { MoveKeyfileToInternalFolder(); };
                 }
 
 
             }
             else
             {
-                importDb.Enabled = false;
+                exportKeyfile.Enabled = false;
+                importKeyfile.Enabled = false;
             }
         }
 
+
+
+        private void ExportKeyfileFromInternalFolder()
+        {
+            StartActivity(new Intent(Activity.ApplicationContext, typeof(ExportKeyfileActivity)));
+            
+        }
+
         private void MoveKeyfileToInternalFolder()
         {
             Func<Action> copyAndReturnPostExecute = () =>

src/keepass2android/settings/ExportKeyfileActivity.cs

@@ -0,0 +1,113 @@
+using System;
+using Android.App;
+using Android.Content;
+using Android.Widget;
+using keepass2android.Io;
+using KeePassLib.Keys;
+using KeePassLib.Serialization;
+
+namespace keepass2android
+{
+    [Activity]
+    public class ExportKeyfileActivity : LockCloseActivity
+    {
+
+        public class ExportKeyfile : RunnableOnFinish
+        {
+            private readonly IKp2aApp _app;
+            private IOConnectionInfo _targetIoc;
+
+            public ExportKeyfile(Activity activity, IKp2aApp app, OnFinish onFinish, IOConnectionInfo targetIoc) : base(
+                activity, onFinish)
+            {
+                _app = app;
+                _targetIoc = targetIoc;
+            }
+
+            public override void Run()
+            {
+                StatusLogger.UpdateMessage(UiStringKey.exporting_database);
+
+                try
+                {
+                    var fileStorage = _app.GetFileStorage(_targetIoc);
+                    if (fileStorage is IOfflineSwitchable)
+                    {
+                        ((IOfflineSwitchable) fileStorage).IsOffline = false;
+                    }
+
+                    CompositeKey masterKey = App.Kp2a.CurrentDb.KpDatabase.MasterKey;
+                    var sourceIoc = ((KcpKeyFile) masterKey.GetUserKey(typeof(KcpKeyFile))).Ioc;
+
+                    IoUtil.Copy(_targetIoc, sourceIoc, App.Kp2a);
+
+                    if (fileStorage is IOfflineSwitchable)
+                    {
+                        ((IOfflineSwitchable) fileStorage).IsOffline = App.Kp2a.OfflineMode;
+                    }
+
+                    Finish(true);
+
+
+                }
+                catch (Exception ex)
+                {
+                    Finish(false, ex.Message);
+                }
+
+
+            }
+        }
+
+
+        public class ExportKeyfileProcessManager : FileSaveProcessManager
+        {
+            public ExportKeyfileProcessManager(int requestCode, Activity activity) : base(requestCode, activity)
+            {
+
+            }
+
+            protected override void SaveFile(IOConnectionInfo ioc)
+            {
+                var exportKeyfile = new ExportKeyfile(_activity, App.Kp2a, new ActionOnFinish(_activity,
+                    (success, message, activity) =>
+                    {
+                        if (!success)
+                            Toast.MakeText(activity, message, ToastLength.Long).Show();
+                        else
+                            Toast.MakeText(activity, _activity.GetString(Resource.String.export_keyfile_successful),
+                                ToastLength.Long).Show();
+                        activity.Finish();
+                    }
+                ), ioc);
+                ProgressTask pt = new ProgressTask(App.Kp2a, _activity, exportKeyfile);
+                pt.Run();
+
+            }
+        }
+
+        private ExportKeyfileProcessManager _exportKeyfileProcessManager;
+
+
+        protected override void OnCreate(Android.OS.Bundle savedInstanceState)
+        {
+            base.OnCreate(savedInstanceState);
+            _exportKeyfileProcessManager = new ExportKeyfileProcessManager(0, this);
+            _exportKeyfileProcessManager.StartProcess();
+
+        }
+
+        protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
+        {
+            base.OnActivityResult(requestCode, resultCode, data);
+
+            if (_exportKeyfileProcessManager?.OnActivityResult(requestCode, resultCode, data) == true)
+                return;
+
+            Finish();
+
+        }
+
+
+    }
+}