Fix #534 by setting default language to english before creating keyge… (#536)

* Fix #534 by setting default language to english before creating keygenerator.

* Fix build!

DeviceTests/DeviceTests.Shared/SecureStorage_Tests.cs

@@ -7,13 +7,13 @@ namespace DeviceTests
     public class SecureStorage_Tests
     {
         [Theory]
-        [InlineData("test.txt", "data", true)]
-        [InlineData("noextension", "data2", true)]
-        [InlineData("funny*&$%@!._/\\chars", "data3", true)]
-        [InlineData("test.txt2", "data2", false)]
-        [InlineData("noextension2", "data22", false)]
-        [InlineData("funny*&$%@!._/\\chars2", "data32", false)]
-        public async Task Saves_And_Loads(string key, string data, bool emulatePreApi23)
+        [InlineData("test.txt", "data", true, true)]
+        [InlineData("noextension", "data2", true, false)]
+        [InlineData("funny*&$%@!._/\\chars", "data3", true, false)]
+        [InlineData("test.txt2", "data2", false, true)]
+        [InlineData("noextension2", "data22", false, false)]
+        [InlineData("funny*&$%@!._/\\chars2", "data32", false, false)]
+        public async Task Saves_And_Loads(string key, string data, bool emulatePreApi23, bool emulateNonEnglishLocale)
         {
 #if __IOS__
             // Try the new platform specific api
@@ -26,6 +26,11 @@ namespace DeviceTests
 
 #if __ANDROID__
             SecureStorage.AlwaysUseAsymmetricKeyStorage = emulatePreApi23;
+
+            if (emulateNonEnglishLocale)
+            {
+                Platform.SetLocale(new Java.Util.Locale("ar"));
+            }
 #endif
 
             await SecureStorage.SetAsync(key, data);

Xamarin.Essentials/Platform/Platform.android.cs

@@ -87,6 +87,31 @@ namespace Xamarin.Essentials
 
         internal static PowerManager PowerManager =>
             AppContext.GetSystemService(Context.PowerService) as PowerManager;
+
+        internal static Java.Util.Locale GetLocale()
+        {
+            var resources = AppContext.Resources;
+            var config = resources.Configuration;
+            if (HasApiLevel(BuildVersionCodes.N))
+                return config.Locales.Get(0);
+
+            return config.Locale;
+        }
+
+        internal static void SetLocale(Java.Util.Locale locale)
+        {
+            Java.Util.Locale.Default = locale;
+            var resources = AppContext.Resources;
+            var config = resources.Configuration;
+            if (HasApiLevel(BuildVersionCodes.N))
+                config.SetLocale(locale);
+            else
+                config.Locale = locale;
+
+#pragma warning disable CS0618 // Type or member is obsolete
+            resources.UpdateConfiguration(config, resources.DisplayMetrics);
+#pragma warning restore CS0618 // Type or member is obsolete
+        }
     }
 
     class ActivityLifecycleContextListener : Java.Lang.Object, Application.IActivityLifecycleCallbacks

Xamarin.Essentials/SecureStorage/SecureStorage.android.cs

@@ -172,27 +172,39 @@ namespace Xamarin.Essentials
             if (privateKey != null && publicKey != null)
                 return new KeyPair(publicKey, privateKey);
 
-            // Otherwise we create a new key
-            var generator = KeyPairGenerator.GetInstance(KeyProperties.KeyAlgorithmRsa, androidKeyStore);
+            var originalLocale = Platform.GetLocale();
+            try
+            {
+                // Force to english for known bug in date parsing:
+                // https://issuetracker.google.com/issues/37095309
+                Platform.SetLocale(Java.Util.Locale.English);
 
-            var end = DateTime.UtcNow.AddYears(20);
-            var startDate = new Java.Util.Date();
+                // Otherwise we create a new key
+                var generator = KeyPairGenerator.GetInstance(KeyProperties.KeyAlgorithmRsa, androidKeyStore);
+
+                var end = DateTime.UtcNow.AddYears(20);
+                var startDate = new Java.Util.Date();
 #pragma warning disable CS0618 // Type or member is obsolete
-            var endDate = new Java.Util.Date(end.Year, end.Month, end.Day);
+                var endDate = new Java.Util.Date(end.Year, end.Month, end.Day);
 #pragma warning restore CS0618 // Type or member is obsolete
 
 #pragma warning disable CS0618
-            var builder = new KeyPairGeneratorSpec.Builder(Platform.AppContext)
-                .SetAlias(asymmetricAlias)
-                .SetSerialNumber(Java.Math.BigInteger.One)
-                .SetSubject(new Javax.Security.Auth.X500.X500Principal($"CN={asymmetricAlias} CA Certificate"))
-                .SetStartDate(startDate)
-                .SetEndDate(endDate);
+                var builder = new KeyPairGeneratorSpec.Builder(Platform.AppContext)
+                    .SetAlias(asymmetricAlias)
+                    .SetSerialNumber(Java.Math.BigInteger.One)
+                    .SetSubject(new Javax.Security.Auth.X500.X500Principal($"CN={asymmetricAlias} CA Certificate"))
+                    .SetStartDate(startDate)
+                    .SetEndDate(endDate);
 
-            generator.Initialize(builder.Build());
+                generator.Initialize(builder.Build());
 #pragma warning restore CS0618
 
-            return generator.GenerateKeyPair();
+                return generator.GenerateKeyPair();
+            }
+            finally
+            {
+                Platform.SetLocale(originalLocale);
+            }
         }
 
         byte[] WrapKey(IKey keyToWrap, IKey withKey)