clear settings for prefix when key is generated

bitwarden-mobile.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.25420.1
+# Visual Studio 15
+VisualStudioVersion = 15.0.26430.13
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Android", "src\Android\Android.csproj", "{04B18ED2-B76D-4947-8474-191F8FD2B5E0}"
 EndProject

src/Android/Services/AndroidKeyStoreStorageService.cs

@@ -11,6 +11,7 @@ using Android.App;
 using Plugin.Settings.Abstractions;
 using Java.Util;
 using Javax.Crypto.Spec;
+using Android.Preferences;
 
 namespace Bit.Android.Services
 {
@@ -22,6 +23,7 @@ namespace Bit.Android.Services
         private const string KeyAlias = "bitwardenKey2";
         private const string KeyAliasV1 = "bitwardenKey";
 
+        private const string SettingsPrefix = "ksSecured2";
         private const string SettingsFormat = "ksSecured2:{0}";
         private const string SettingsFormatV1 = "ksSecured:{0}";
 
@@ -91,7 +93,7 @@ namespace Bit.Android.Services
             {
                 return App.Utilities.Crypto.AesCbcDecrypt(new App.Models.CipherString(cs), aesKey);
             }
-            catch(Exception)
+            catch
             {
                 Console.WriteLine("Failed to decrypt from secure storage.");
                 _settings.Remove(formattedKey);
@@ -121,7 +123,7 @@ namespace Bit.Android.Services
                 var cipherString = App.Utilities.Crypto.AesCbcEncrypt(dataBytes, aesKey);
                 _settings.AddOrUpdateValue(formattedKey, cipherString.EncryptedString);
             }
-            catch(Exception)
+            catch
             {
                 Console.WriteLine("Failed to encrypt to secure storage.");
                 //Utilities.SendCrashEmail(e);
@@ -135,6 +137,8 @@ namespace Bit.Android.Services
                 return;
             }
 
+            ClearSettings();
+
             var end = Calendar.Instance;
             end.Add(CalendarField.Year, 99);
 
@@ -222,7 +226,7 @@ namespace Bit.Android.Services
                     return new App.Models.SymmetricCryptoKey(key);
                 }
             }
-            catch(Exception)
+            catch
             {
                 Console.WriteLine("Cannot get AesKey.");
                 _keyStore.DeleteEntry(KeyAlias);
@@ -336,5 +340,27 @@ namespace Bit.Android.Services
                 _settings.Remove(formattedKeyV1);
             }
         }
+
+        private void ClearSettings(string prefix = SettingsPrefix)
+        {
+            using(var sharedPreferences = PreferenceManager.GetDefaultSharedPreferences(Application.Context))
+            using(var sharedPreferencesEditor = sharedPreferences.Edit())
+            {
+                var removed = false;
+                foreach(var pref in sharedPreferences.All)
+                {
+                    if(pref.Key.StartsWith(prefix))
+                    {
+                        removed = true;
+                        sharedPreferencesEditor.Remove(pref.Key);
+                    }
+                }
+
+                if(removed)
+                {
+                    sharedPreferencesEditor.Commit();
+                }
+            }
+        }
     }
 }