Fix rest json de/serialization backwards compatibility

src/fiskaltrust.Launcher/Helpers/CustomDateTimeConverter.cs

@@ -0,0 +1,69 @@
+using System.Globalization;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Text.RegularExpressions;
+
+namespace fiskaltrust.Launcher.Helpers
+{
+    sealed class CustomDateTimeConverter : JsonConverter<DateTime>
+    {
+        private readonly static JsonConverter<DateTime> DEFAULT_CONVERTER = (JsonConverter<DateTime>)JsonSerializerOptions.Default.GetConverter(typeof(DateTime));
+        static readonly DateTime EPOCH = new DateTime(1970, 1, 1, 0, 0, 0);
+        static readonly DateTimeOffset EPOCH_OFFSET = new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero);
+
+        static readonly Regex REGEX = new Regex("^\\\\?/Date\\(([+-]*\\d+)\\)\\\\?/$", RegexOptions.CultureInvariant);
+
+        static readonly Regex REGEX_OFFSET = new Regex("^\\\\?/Date\\(([+-]*\\d+)([+-])(\\d{2})(\\d{2})\\)\\\\?/$", RegexOptions.CultureInvariant);
+
+        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            string formatted = reader.GetString()!;
+
+            {
+                Match match = REGEX_OFFSET.Match(formatted);
+
+                if (match.Success)
+                {
+                    return ReadDateTimeOffset(match).DateTime;
+                }
+            }
+
+            {
+                Match match = REGEX.Match(formatted);
+
+                if (match.Success)
+                {
+                    return ReadDateTime(match);
+                }
+            }
+
+            return DEFAULT_CONVERTER.Read(ref reader, typeToConvert, options);
+        }
+
+        private DateTime ReadDateTime(Match date)
+        {
+            if (!long.TryParse(date.Groups[1].Value, NumberStyles.Integer, CultureInfo.InvariantCulture, out long unixTime))
+            {
+                throw new JsonException();
+            }
+
+            return EPOCH.AddMilliseconds(unixTime);
+        }
+
+        private DateTimeOffset ReadDateTimeOffset(Match date)
+        {
+            if (!long.TryParse(date.Groups[1].Value, NumberStyles.Integer, CultureInfo.InvariantCulture, out long unixTime)
+                || !int.TryParse(date.Groups[3].Value, NumberStyles.Integer, CultureInfo.InvariantCulture, out int hours)
+                || !int.TryParse(date.Groups[4].Value, NumberStyles.Integer, CultureInfo.InvariantCulture, out int minutes))
+            {
+                throw new JsonException();
+            }
+
+            int sign = date.Groups[2].Value[0] == '+' ? 1 : -1;
+            TimeSpan utcOffset = new TimeSpan(hours * sign, minutes * sign, 0);
+            return EPOCH_OFFSET.AddMilliseconds(unixTime).ToOffset(utcOffset);
+        }
+
+        public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options) => DEFAULT_CONVERTER.Write(writer, value, options);
+    }
+}

src/fiskaltrust.Launcher/Helpers/NumberToStringConverter.cs

@@ -6,6 +6,8 @@ namespace fiskaltrust.Launcher.Helpers
 {
     public class NumberToStringConverter : JsonConverter<string>
     {
+        private readonly static JsonConverter<string> DEFAULT_CONVERTER = (JsonConverter<string>)JsonSerializerOptions.Default.GetConverter(typeof(string));
+
         public override string? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
         {
             if (reader.TokenType == JsonTokenType.Number)
@@ -15,7 +17,7 @@ public class NumberToStringConverter : JsonConverter<string>
                     return number.ToString(CultureInfo.InvariantCulture);
                 }
 
-                if (reader.TryGetDouble(out var doubleNumber))
+                if (reader.TryGetDecimal(out var doubleNumber))
                 {
                     return doubleNumber.ToString(CultureInfo.InvariantCulture);
                 }
@@ -29,9 +31,6 @@ public class NumberToStringConverter : JsonConverter<string>
             return null;
         }
 
-        public override void Write(Utf8JsonWriter writer, string value, JsonSerializerOptions options)
-        {
-            writer.WriteStringValue(value.ToString());
-        }
+        public override void Write(Utf8JsonWriter writer, string value, JsonSerializerOptions options) => DEFAULT_CONVERTER.Write(writer, value, options);
     }
 }

src/fiskaltrust.Launcher/Services/HostingService.cs

@@ -18,6 +18,7 @@
 using System.Security.Cryptography.X509Certificates;
 using System.Runtime.Versioning;
 using Microsoft.AspNetCore.Server.HttpSys;
+using System.Text.Json;
 
 namespace fiskaltrust.Launcher.Services
 {
@@ -133,6 +134,10 @@ private WebApplication CreateRestHost<T>(WebApplicationBuilder builder, Uri uri,
             {
                 options.SerializerOptions.NumberHandling = System.Text.Json.Serialization.JsonNumberHandling.AllowReadingFromString;
                 options.SerializerOptions.Converters.Add(new NumberToStringConverter());
+                options.SerializerOptions.Converters.Add(new CustomDateTimeConverter());
+                options.SerializerOptions.Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping;
+                options.SerializerOptions.PropertyNamingPolicy = null;
+                options.SerializerOptions.DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull;
             });
 
             builder.WebHost.ConfigureBinding(uri, listenOptions => ConfigureTls(listenOptions), isHttps: !string.IsNullOrEmpty(_launcherConfiguration.TlsCertificatePath) || !string.IsNullOrEmpty(_launcherConfiguration.TlsCertificateBase64), allowSynchronousIO: true, useHttpSys: _launcherConfiguration.UseHttpSysBinding!.Value);

version.json

@@ -1,5 +1,5 @@
 {
-  "version": "2.0.0-rc.9",
+  "version": "2.0.0-rc.10",
   "releaseBranches": [
     "^refs/tags/v\\d+(?:\\.\\d+)*(?:-.*)?$"
   ]