diff --git a/LibMatrix.Federation/Utilities/JsonSigning.cs b/LibMatrix.Federation/Utilities/JsonSigning.cs
new file mode 100644
index 0000000..c727cde
--- /dev/null
+++ b/LibMatrix.Federation/Utilities/JsonSigning.cs
@@ -0,0 +1,108 @@
+using System.Globalization;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using System.Text.Json.Serialization;
+using ArcaneLibs.Extensions;
+using LibMatrix.Extensions;
+using LibMatrix.FederationTest.Utilities;
+using LibMatrix.Homeservers;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Math.EC.Rfc8032;
+
+namespace LibMatrix.Federation.Utilities;
+
+public static class JsonSigning { }
+
+[JsonConverter(typeof(SignedObjectConverterFactory))]
+public class SignedObject<T> {
+ [JsonPropertyName("signatures")]
+ public Dictionary<string, Dictionary<string, string>> Signatures { get; set; } = new();
+
+ [JsonIgnore]
+ public Dictionary<string, Dictionary<ServerKeysResponse.VersionedKeyId, string>> VerifyKeysById {
+ get => Signatures.ToDictionary(server => server.Key, server => server.Value.ToDictionary(key => (ServerKeysResponse.VersionedKeyId)key.Key, key => key.Value));
+ set => Signatures = value.ToDictionary(server => server.Key, server => server.Value.ToDictionary(key => (string)key.Key, key => key.Value));
+ }
+
+ [JsonExtensionData]
+ public required JsonObject Content { get; set; }
+
+ [JsonIgnore]
+ public T TypedContent {
+ get => Content.Deserialize<T>() ?? throw new JsonException("Failed to deserialize TypedContent from Content.");
+ set => Content = JsonSerializer.Deserialize<JsonObject>(JsonSerializer.Serialize(value)) ?? new JsonObject();
+ }
+}
+
+// Content needs to be merged at toplevel
+public class SignedObjectConverter<T> : JsonConverter<SignedObject<T>> {
+ public override SignedObject<T> Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
+ var jsonObject = JsonSerializer.Deserialize<JsonObject>(ref reader, options);
+ if (jsonObject == null) {
+ throw new JsonException("Failed to deserialize SignedObject, JSON object is null.");
+ }
+
+ var signatures = jsonObject["signatures"] ?? throw new JsonException("Failed to find 'signatures' property in JSON object.");
+ jsonObject.Remove("signatures");
+
+ var signedObject = new SignedObject<T> {
+ Content = jsonObject,
+ Signatures = signatures.Deserialize<Dictionary<string, Dictionary<string, string>>>()
+ ?? throw new JsonException("Failed to deserialize 'signatures' property into Dictionary<string, Dictionary<string, string>>.")
+ };
+
+ return signedObject;
+ }
+
+ public override void Write(Utf8JsonWriter writer, SignedObject<T> value, JsonSerializerOptions options) {
+ var targetObj = value.Content.DeepClone();
+ targetObj["signatures"] = value.Signatures.ToJsonNode();
+ JsonSerializer.Serialize(writer, targetObj, options);
+ }
+}
+
+internal class SignedObjectConverterFactory : JsonConverterFactory {
+ public override bool CanConvert(Type typeToConvert) {
+ if (!typeToConvert.IsGenericType) return false;
+ return typeToConvert.GetGenericTypeDefinition() == typeof(SignedObject<>);
+ }
+
+ public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options) {
+ var wrappedType = typeToConvert.GetGenericArguments()[0];
+ var converter = (JsonConverter)Activator.CreateInstance(typeof(SignedObjectConverter<>).MakeGenericType(wrappedType))!;
+ return converter;
+ }
+}
+
+public static class ObjectExtensions {
+ public static SignedObject<T> Sign<T>(this SignedObject<T> content, string serverName, string keyName, Ed25519PrivateKeyParameters key) {
+ var signResult = Sign(content.Content, serverName, keyName, key);
+ var signedObject = new SignedObject<T> {
+ Signatures = content.Signatures,
+ Content = signResult.Content
+ };
+
+ if (!signedObject.Signatures.ContainsKey(serverName))
+ signedObject.Signatures[serverName] = new Dictionary<string, string>();
+
+ signedObject.Signatures[serverName][keyName] = signResult.Signatures[serverName][keyName];
+ return signedObject;
+ }
+
+ public static SignedObject<T> Sign<T>(this T content, string serverName, string keyName, Ed25519PrivateKeyParameters key) {
+ SignedObject<T> signedObject = new() {
+ Signatures = [],
+ Content = JsonSerializer.Deserialize<JsonObject>(JsonSerializer.Serialize(content)) ?? new JsonObject(),
+ };
+
+ var contentBytes = CanonicalJsonSerializer.SerializeToUtf8Bytes(signedObject.Content);
+ var signature = new byte[Ed25519.SignatureSize];
+ key.Sign(Ed25519.Algorithm.Ed25519, null, contentBytes, 0, contentBytes.Length, signature, 0);
+
+ if (!signedObject.Signatures.ContainsKey(serverName))
+ signedObject.Signatures[serverName] = new Dictionary<string, string>();
+
+ signedObject.Signatures[serverName][keyName] = UnpaddedBase64.Encode(signature);
+ return signedObject;
+ }
+}
\ No newline at end of file
diff --git a/LibMatrix.Federation/Utilities/UnpaddedBase64.cs b/LibMatrix.Federation/Utilities/UnpaddedBase64.cs
new file mode 100644
index 0000000..06f84b2
--- /dev/null
+++ b/LibMatrix.Federation/Utilities/UnpaddedBase64.cs
@@ -0,0 +1,17 @@
+namespace LibMatrix.FederationTest.Utilities;
+
+public static class UnpaddedBase64 {
+ public static string Encode(byte[] data) {
+ return Convert.ToBase64String(data).TrimEnd('=');
+ }
+
+ public static byte[] Decode(string base64) {
+ string paddedBase64 = base64;
+ switch (paddedBase64.Length % 4) {
+ case 2: paddedBase64 += "=="; break;
+ case 3: paddedBase64 += "="; break;
+ }
+
+ return Convert.FromBase64String(paddedBase64);
+ }
+}
\ No newline at end of file
|
