implement editor for TOTP settings in EntryEditActivity, closes https://github.com/PhilippC/keepass2android/issues/770

src/keepass2android/EntryEditActivity.cs

@@ -33,12 +33,17 @@ using KeePassLib.Security;
 using Android.Content.PM;
 using System.IO;
 using System.Globalization;
+using System.Net;
+using System.Text;
+using Android.Content.Res;
 using Android.Database;
 using Android.Graphics;
 using Android.Graphics.Drawables;
 using Android.Util;
 using keepass2android.Io;
 using KeePassLib.Serialization;
+using KeeTrayTOTP.Libraries;
+using PluginTOTP;
 using Debug = System.Diagnostics.Debug;
 using File = System.IO.File;
 using Object = Java.Lang.Object;
@@ -287,7 +292,31 @@ namespace keepass2android
 				EditAdvancedString(ees.FindViewById(Resource.Id.edit_extra));
 			};
 			SetAddExtraStringEnabled();
-		    FindViewById(Resource.Id.entry_extras_container).Visibility =
+			
+
+            Button configureTotpButton = (Button)FindViewById(Resource.Id.configure_totp);
+
+            configureTotpButton.Visibility = CanConfigureOtpSettings() ? ViewStates.Gone : ViewStates.Visible;
+			configureTotpButton.Click += (sender, e) =>
+            {
+                bool added = false;
+                View ees = FindExtraEditSection("otp");
+				if (ees == null)
+                {
+                    LinearLayout container = (LinearLayout) FindViewById(Resource.Id.advanced_container);
+
+                    KeyValuePair<string, ProtectedString> pair =
+                        new KeyValuePair<string, ProtectedString>("otp", new ProtectedString(true, ""));
+                    ees = CreateExtraStringView(pair);
+                    container.AddView(ees);
+                    added = true;
+                }
+                
+
+				EditTotpString(ees.FindViewById(Resource.Id.edit_extra));
+            };
+
+			FindViewById(Resource.Id.entry_extras_container).Visibility =
 		        State.EditMode.ShowAddExtras || State.Entry.Strings.Any(s => !PwDefs.IsStandardField(s.Key)) ? ViewStates.Visible : ViewStates.Gone;
 		    FindViewById(Resource.Id.entry_binaries_container).Visibility =
 		        State.EditMode.ShowAddAttachments || State.Entry.Binaries.Any() ? ViewStates.Visible : ViewStates.Gone;
@@ -402,9 +431,17 @@ namespace keepass2android
 		private void SetAddExtraStringEnabled()
 		{
 			((Button)FindViewById(Resource.Id.add_advanced)).Visibility = (!App.Kp2a.CurrentDb.DatabaseFormat.CanHaveCustomFields || !State.EditMode.ShowAddExtras) ? ViewStates.Gone : ViewStates.Visible;
+            ((Button)FindViewById(Resource.Id.configure_totp)).Visibility = CanConfigureOtpSettings() ? ViewStates.Gone : ViewStates.Visible;
 		}
 
-		private void MakePasswordVisibleOrHidden()
+        private bool CanConfigureOtpSettings()
+        {
+            return (!App.Kp2a.CurrentDb.DatabaseFormat.CanHaveCustomFields || !State.EditMode.ShowAddExtras) 
+                && (new Kp2aTotp().TryGetAdapter(new PwEntryOutput(State.Entry, App.Kp2a.CurrentDb)) == null || (State.Entry.Strings.GetKeys().Contains("otp"))) //only allow to edit KeeWeb/KeepassXC style otps
+                ;
+        }
+
+        private void MakePasswordVisibleOrHidden()
 		{
 		    EditText password = (EditText) FindViewById(Resource.Id.entry_password);
 			TextView confpassword = (TextView) FindViewById(Resource.Id.entry_confpassword);
@@ -942,7 +979,8 @@ namespace keepass2android
                     binariesGroup.Visibility = ViewStates.Visible;
                     FindViewById(Resource.Id.entry_binaries_container).Visibility = ViewStates.Visible;
                     ((Button)FindViewById(Resource.Id.add_advanced)).Visibility = ViewStates.Visible;
-                    FindViewById(Resource.Id.entry_extras_container).Visibility = ViewStates.Visible;
+                    ((Button)FindViewById(Resource.Id.configure_totp)).Visibility = ViewStates.Visible;
+					FindViewById(Resource.Id.entry_extras_container).Visibility = ViewStates.Visible;
 
                     return true;
                 case Android.Resource.Id.Home:
@@ -1020,6 +1058,7 @@ namespace keepass2android
 			if (type == "bool")
 			{
 				RelativeLayout ees = (RelativeLayout)LayoutInflater.Inflate(Resource.Layout.entry_edit_section_bool, null);
+                ees.Tag = pair.Key;
 				var keyView = ((TextView)ees.FindViewById(Resource.Id.extrakey));
 				var checkbox = ((CheckBox)ees.FindViewById(Resource.Id.checkbox));
 			    var valueView = ((TextView)ees.FindViewById(Resource.Id.value));
@@ -1037,6 +1076,7 @@ namespace keepass2android
 			else if (type == "file")
 			{
 				RelativeLayout ees = (RelativeLayout)LayoutInflater.Inflate(Resource.Layout.entry_edit_section_file, null);
+                ees.Tag = pair.Key;
 				var keyView = ((TextView)ees.FindViewById(Resource.Id.extrakey));
 				var titleView = ((TextView)ees.FindViewById(Resource.Id.title));
 				keyView.Text = pair.Key;
@@ -1054,6 +1094,7 @@ namespace keepass2android
 			else
 			{
 				RelativeLayout ees = (RelativeLayout)LayoutInflater.Inflate(Resource.Layout.entry_edit_section, null);
+                ees.Tag = pair.Key;
 				var keyView = ((TextView)ees.FindViewById(Resource.Id.extrakey));
 				var titleView = ((TextView)ees.FindViewById(Resource.Id.title));
 				keyView.Text = pair.Key;
@@ -1090,8 +1131,184 @@ namespace keepass2android
 		    }
 		    
 	    }
+		
+        private void EditTotpString(View sender)
+        {
+            AlertDialog.Builder builder = new AlertDialog.Builder(this);
+            View dlgView = LayoutInflater.Inflate(Resource.Layout.
+                configure_totp_dialog, null);
 
-	    private void EditAdvancedString(View sender)
+
+
+            builder.SetView(dlgView);
+            builder.SetNegativeButton(Android.Resource.String.Cancel, (o, args) => { });
+            builder.SetPositiveButton(Android.Resource.String.Ok, (o, args) =>
+            {
+                
+                var targetField = ((TextView)((View)sender.Parent).FindViewById(Resource.Id.value));
+                if (targetField != null)
+                {
+                    string entryTitle = Util.GetEditText(this, Resource.Id.entry_title);
+                    string username = Util.GetEditText(this, Resource.Id.entry_user_name);
+                    string secret = dlgView.FindViewById<TextView>(Resource.Id.totp_secret_key).Text;
+                    string totpLength = dlgView.FindViewById<EditText>(Resource.Id.totp_length).Text;
+                    string timeStep = dlgView.FindViewById<EditText>(Resource.Id.totp_time_step).Text;
+                    var checkedTotpId = (int)dlgView.FindViewById<RadioGroup>(Resource.Id.totp_encoding).CheckedRadioButtonId;
+                    TotpEncoding encoding = (checkedTotpId == Resource.Id.totp_encoding_steam)
+                        ? TotpEncoding.Steam : (checkedTotpId == Resource.Id.totp_encoding_rfc6238 ? TotpEncoding.Default : TotpEncoding.Custom);
+                    var algorithm = (int)dlgView.FindViewById<Spinner>(Resource.Id.totp_algorithm).SelectedItemPosition;
+
+                    targetField.Text = BuildOtpString(entryTitle, username, secret, totpLength, timeStep, encoding, algorithm);
+				}
+                else
+                {
+					Toast.MakeText(this, "did not find target field", ToastLength.Long).Show();
+                }
+                
+				
+				//not calling State.Entry.Strings.Set(...). We only do this when the user saves the changes.
+				State.EntryModified = true;
+
+			});
+            Dialog dialog = builder.Create();
+
+            dlgView.FindViewById<RadioButton>(Resource.Id.totp_encoding_custom).CheckedChange += (o, args) =>
+            {
+                dlgView.FindViewById(Resource.Id.totp_custom_settings_group).Visibility = args.IsChecked ? ViewStates.Visible : ViewStates.Gone;
+            };
+
+
+			//copy values from entry into dialog
+			View ees = (View)sender.Parent;
+            TotpData totpData = new Kp2aTotp().TryGetTotpData(new PwEntryOutput(State.Entry, App.Kp2a.CurrentDb));
+            if (totpData != null)
+            {
+                dlgView.FindViewById<TextView>(Resource.Id.totp_secret_key).Text = totpData.TotpSeed;
+                if (totpData.Encoder == TotpData.EncoderSteam)
+                {
+                    dlgView.FindViewById<RadioButton>(Resource.Id.totp_encoding_steam).Checked = true;
+                } 
+                else if ((totpData.Encoder == TotpData.EncoderRfc6238) && (totpData.IsDefaultRfc6238))
+				{
+                    dlgView.FindViewById<RadioButton>(Resource.Id.totp_encoding_rfc6238).Checked = true;
+				}
+				else
+                {
+                    dlgView.FindViewById<RadioButton>(Resource.Id.totp_encoding_custom).Checked = true;
+				}
+
+                dlgView.FindViewById<EditText>(Resource.Id.totp_length).Text = totpData.Length;
+                dlgView.FindViewById<EditText>(Resource.Id.totp_time_step).Text = totpData.Duration;
+                dlgView.FindViewById <Spinner>(Resource.Id.totp_algorithm).SetSelection(totpData.HashAlgorithm == TotpData.HashSha1 ? 0 : (
+                        totpData.HashAlgorithm == TotpData.HashSha256 ? 1:
+                            (totpData.HashAlgorithm == TotpData.HashSha256 ? 2 : 0)));
+
+                dlgView.FindViewById(Resource.Id.totp_custom_settings_group).Visibility = dlgView.FindViewById<RadioButton>(Resource.Id.totp_encoding_custom).Checked ? ViewStates.Visible : ViewStates.Gone;
+			}
+            
+            _passwordFont.ApplyTo(dlgView.FindViewById<EditText>(Resource.Id.totp_secret_key));
+            Util.SetNoPersonalizedLearning(dlgView);
+            
+
+
+            dialog.Show();
+
+        }
+
+        string SanitizeInput(string encodedData)
+        {
+            if (encodedData.Length <= 0)
+            {
+                return encodedData;
+            }
+
+			StringBuilder newEncodedDataBuilder = new StringBuilder(encodedData);
+            int i = 0;
+            foreach (var ch in encodedData)
+            {
+                switch (ch)
+                {
+                    case '0':
+                        newEncodedDataBuilder[i++] = 'O';
+                        break;
+                    case '1':
+                        newEncodedDataBuilder[i++] = 'L';
+                        break;
+                    case '8':
+                        newEncodedDataBuilder[i++] = 'B';
+                        break;
+                    default:
+                        if (('A' <= ch && ch <= 'Z') || ('a' <= ch && ch <= 'z') || ('2' <= ch && ch <= '7'))
+                        {
+                            newEncodedDataBuilder[i++] = ch;
+                        }
+
+                        break;
+                }
+            }
+
+            string newEncodedData = newEncodedDataBuilder.ToString().Substring(0, i);
+
+            return AddPadding(newEncodedData);
+        
+		}
+
+
+        string AddPadding(string encodedData)
+        {
+            if (encodedData.Length <= 0 || encodedData.Length % 8 == 0) {
+                return encodedData;
+            }
+
+            int rBytes = encodedData.Length % 8;
+            // rBytes must be a member of {2, 4, 5, 7}
+            if (1 == rBytes || 3 == rBytes || 6 == rBytes) {
+                return encodedData;
+            }
+
+            string newEncodedData = encodedData;
+            for (int nPads = 8 - rBytes; nPads > 0; --nPads)
+            {
+                newEncodedData += "=";
+            }
+
+            return newEncodedData;
+        }
+
+        enum TotpEncoding
+        {
+			Default, Steam, Custom
+        }
+
+		private string BuildOtpString(string entryTitle, string userName, string secret, string totpLength, string timeStep, TotpEncoding encoding, int algorithm)
+        {
+            string entryEncoded = string.IsNullOrWhiteSpace(entryTitle)
+                ? "Keepass2Android"
+                : System.Uri.EscapeUriString(entryTitle);
+			return $"otpauth://totp/{entryEncoded}:{System.Uri.EscapeUriString(userName)}?" +
+                   $"secret={SanitizeInput(secret)}" +
+				   $"&issuer={ entryEncoded}"
+					   + (encoding != TotpEncoding.Custom? "" : $"&period={timeStep}&digits={totpLength}&algorithm={AlgorithmIndexToString(algorithm)}") +
+                   (encoding  == TotpEncoding.Steam ? "&encoder=steam" : "");
+
+		}
+
+        private string AlgorithmIndexToString(in int algorithm)
+        {
+            switch (algorithm)
+            {
+				case 0:
+                    return "SHA1";
+				case 1:
+                    return "SHA256";
+                case 2:
+                    return "SHA512";
+				default:
+                    return "";
+			}
+        }
+
+        private void EditAdvancedString(View sender)
 		{
 			AlertDialog.Builder builder = new AlertDialog.Builder(this);
 			View dlgView = LayoutInflater.Inflate(Resource.Layout.

src/keepass2android/Resources/drawable/baseline_schedule_24.xml

@@ -0,0 +1,13 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M11.99,2C6.47,2 2,6.48 2,12s4.47,10 9.99,10C17.52,22 22,17.52 22,12S17.52,2 11.99,2zM12,20c-4.42,0 -8,-3.58 -8,-8s3.58,-8 8,-8 8,3.58 8,8 -3.58,8 -8,8z"/>
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M12.5,7H11v6l5.25,3.15 0.75,-1.23 -4.5,-2.67z"/>
+</vector>

src/keepass2android/Resources/layout/configure_totp_dialog.xml

@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:layout_width="fill_parent"
+    android:layout_height="wrap_content">
+
+    <EditText
+        android:id="@+id/totp_secret_key"
+        android:singleLine="true"
+        android:inputType="text"
+        android:hint="@string/totp_secret_key"
+        android:dropDownWidth="match_parent"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        />
+
+    <RadioGroup
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:id="@+id/totp_encoding">
+        <RadioButton
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:checked="true"
+            android:text="@string/totp_encoding_rfc6238"
+            android:id="@+id/totp_encoding_rfc6238" />
+        <RadioButton
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/totp_encoding_steam"
+            android:id="@+id/totp_encoding_steam" />
+        <RadioButton
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/totp_encoding_custom"
+            android:id="@+id/totp_encoding_custom" />
+    </RadioGroup>
+    <LinearLayout
+        android:orientation="vertical"
+        android:minWidth="25px"
+        android:minHeight="25px"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:id="@+id/totp_custom_settings_group">
+        <Spinner
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:entries="@array/totp_algorithms"
+            android:prompt="@string/algorithm"
+            android:id="@+id/totp_algorithm" />
+        <EditText
+            android:inputType="numberDecimal"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:hint="@string/totp_time_step"
+            android:id="@+id/totp_time_step" />
+
+        <EditText
+            android:inputType="numberDecimal"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:hint="@string/totp_length"
+            android:id="@+id/totp_length" />
+
+    </LinearLayout>
+
+
+</LinearLayout>

src/keepass2android/Resources/layout/entry_edit.xml

@@ -177,6 +177,19 @@
     android:layout_weight="1"
     android:layout_height="wrap_content"
     android:text="@string/add_extra_string"/>
+
+            <Button
+              android:id="@+id/configure_totp"
+              android:background="?android:selectableItemBackground"
+              android:textColor="?android:attr/textColorPrimary"
+              android:textAppearance="?android:attr/textAppearanceSmall"
+              android:textAllCaps="true"
+              android:paddingLeft="8dp"
+              android:layout_width="match_parent"
+              android:layout_weight="1"
+              android:layout_height="wrap_content"
+              android:drawableLeft="@drawable/baseline_schedule_white_24"
+              android:text="@string/configure_totp"/>
                 
             </LinearLayout>
         </LinearLayout>

src/keepass2android/Resources/values/config.xml

@@ -177,6 +177,12 @@
     	<item>28</item>
     </string-array>
 
+  <string-array name="totp_algorithms">
+    <item>SHA-1</item>
+    <item>SHA-256</item>
+    <item>SHA-512</item>
+  </string-array>
+
 	<string name="design_default">System</string>
 	<string-array name="design_values">
 		<item>Light</item>

src/keepass2android/Resources/values/strings.xml

@@ -346,7 +346,15 @@
   <string name="protection">Protected field</string>
   <string name="add_binary">Add file attachment</string>
   <string name="add_extra_string">Add additional string</string>
-	<string name="delete_extra_string">Delete additional string</string>
+  <string name="configure_totp">Configure TOTP</string>
+  <string name="totp_secret_key">Secret key</string>
+  <string name="totp_encoding_rfc6238">Default RFC6238 token settings</string>
+  <string name="totp_encoding_steam">Steam token settings</string>
+  <string name="totp_encoding_custom">Custom token settings</string>
+  <string name="totp_time_step">Time step</string>
+  <string name="totp_length">Code length</string>
+  
+  <string name="delete_extra_string">Delete additional string</string>
 	<string name="database_loaded_quickunlock_enabled">%1$s: Locked. QuickUnlock enabled.</string>
 	<string name="database_loaded_unlocked">%1$s: Unlocked.</string>
   <string name="credentials_dialog_title">Enter server credentials</string>

src/keepass2android/Totp/KeeWebOtpPluginAdapter.cs

@@ -33,9 +33,9 @@ namespace keepass2android
                 res.Encoder = parsedQuery.Get("encoder");
                 string algo = parsedQuery.Get("algorithm");
                 if (algo == "SHA512")
-                    res.HashAlgorithm = "HMAC-SHA-512";
+                    res.HashAlgorithm = TotpData.HashSha512;
                 if (algo == "SHA256")
-                    res.HashAlgorithm = "HMAC-SHA-256";
+                    res.HashAlgorithm = TotpData.HashSha256;
 
 
                 //set defaults according to https://github.com/google/google-authenticator/wiki/Key-Uri-Format

src/keepass2android/Totp/Keepass2TotpPluginAdapter.cs

@@ -42,7 +42,7 @@ namespace PluginTOTP
             string strAlg;
             entryFields.TryGetValue("TimeOtp-Algorithm", out strAlg);
 
-
+            res.HashAlgorithm = strAlg;
             res.TotpSecret = pbSecret;
             res.Length = uLength.ToString();
             res.Duration = uPeriod.ToString();

src/keepass2android/Totp/Kp2aTotp.cs

@@ -19,6 +19,23 @@ namespace keepass2android
             new Keepass2TotpPluginAdapter(),
         };
 
+
+        public TotpData TryGetTotpData(PwEntryOutput entry)
+        {
+            if (entry == null)
+                return null;
+            foreach (ITotpPluginAdapter adapter in _pluginAdapters)
+            {
+                TotpData totpData = adapter.GetTotpData(entry.OutputStrings.ToDictionary(pair => StrUtil.SafeXmlString(pair.Key), pair => pair.Value.ReadString()), Application.Context, false);
+                if (totpData.IsTotpEntry)
+                {
+                    return totpData;
+                }
+            }
+
+            return null;
+        }
+
         public ITotpPluginAdapter TryGetAdapter(PwEntryOutput entry)
         {
             if (entry == null)

src/keepass2android/Totp/TOTPProvider.cs

@@ -127,7 +127,7 @@ namespace KeeTrayTOTP.Libraries
                 this.encoder = TOTPEncoder.rfc6238;
             }
 
-            if(data.Url != null)
+            if(data.TimeCorrectionUrl != null)
             {
                 {
                     this.TimeCorrection = TimeSpan.Zero;

src/keepass2android/Totp/TotpData.cs

@@ -7,11 +7,14 @@ namespace PluginTOTP
     {
         public TotpData()
         {
-            HashAlgorithm = "HMAC-SHA-1";
+            HashAlgorithm = HashSha1;
         }
 
         public const string EncoderSteam = "steam";
         public const string EncoderRfc6238 = "rfc6238";
+        public const string HashSha1 = "HMAC-SHA-1";
+        public const string HashSha256 = "HMAC-SHA-256";
+        public const string HashSha512 = "HMAC-SHA-512";
 
 
         public bool IsTotpEntry { get; set; }
@@ -20,12 +23,28 @@ namespace PluginTOTP
 		public string TotpSeed
         {
             set { TotpSecret = Base32.Decode(value.Trim()); }
+            get { return Base32.Encode(TotpSecret); }
         }
 		public string Duration { get; set; }
         public string Encoder { get; set; }
         public string Length { get; set; }
-		public string Url { get; set; }
+		public string TimeCorrectionUrl { get; set; }
 
         public string HashAlgorithm { get; set; }
+
+        public bool IsDefaultRfc6238
+        {
+            get { return Length == "6" && Duration == "30" && (HashAlgorithm == null || HashAlgorithm == HashSha1); }
+        }
+
+        public static TotpData MakeDefaultRfc6238()
+        {
+            return new TotpData()
+            {
+                Duration = "30",
+                Length = "6",
+                HashAlgorithm = HashSha1
+            };
+        }
     }
 }

src/keepass2android/Totp/TrayTotpPluginAdapter.cs

@@ -122,7 +122,7 @@ namespace PluginTOTP
 						if (ValidUrl)
 						{
 							NoTimeCorrection = true;
-							res.Url = Settings[2];
+							res.TimeCorrectionUrl = Settings[2];
 							/*var CurrentTimeCorrection = TimeCorrections[Settings[2]];
 							if (CurrentTimeCorrection != null)
 							{

src/keepass2android/keepass2android.csproj

@@ -314,9 +314,6 @@
     <None Include="Resources\drawable-xhdpi\2_action_about.png">
       <Visible>False</Visible>
     </None>
-    <AndroidResource Include="Resources\layout\edit_extra_string_dialog.xml">
-      <SubType>AndroidResource</SubType>
-    </AndroidResource>
     <AndroidResource Include="Resources\layout\file_storage_setup.xml">
       <SubType>AndroidResource</SubType>
     </AndroidResource>
@@ -2070,6 +2067,21 @@
   <ItemGroup>
     <AndroidResource Include="Resources\menu\menu_selectdb.xml" />
   </ItemGroup>
+  <ItemGroup>
+    <AndroidResource Include="Resources\layout\configure_totp_dialog.xml">
+      <SubType>AndroidResource</SubType>
+      <Generator>MSBuild:UpdateGeneratedFiles</Generator>
+    </AndroidResource>
+  </ItemGroup>
+  <ItemGroup>
+    <AndroidResource Include="Resources\layout\edit_extra_string_dialog.xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <AndroidResource Include="Resources\drawable\baseline_schedule_24.xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <AndroidResource Include="Resources\drawable-xhdpi\baseline_schedule_white_24.png" />
+  </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>