Update: Added RelayServer Logic

RelayServer/Services/ChannelCryptoService.cs

@@ -0,0 +1,44 @@
+using System.Security.Cryptography;
+using System.Text;
+
+namespace RelayServer.Services;
+
+public sealed class ChannelCryptoService
+{
+    public string GenerateKey()
+    {
+        return Convert.ToBase64String(RandomNumberGenerator.GetBytes(32));
+    }
+
+    public (string cipherText, string nonce, string tag) Encrypt(string plainText, string keyBase64)
+    {
+        var key = Convert.FromBase64String(keyBase64);
+        var nonce = RandomNumberGenerator.GetBytes(12);
+        var plainBytes = Encoding.UTF8.GetBytes(plainText);
+        var cipherBytes = new byte[plainBytes.Length];
+        var tag = new byte[16];
+
+        using var aes = new AesGcm(key, 16);
+        aes.Encrypt(nonce, plainBytes, cipherBytes, tag);
+
+        return (
+            Convert.ToBase64String(cipherBytes),
+            Convert.ToBase64String(nonce),
+            Convert.ToBase64String(tag)
+        );
+    }
+
+    public string Decrypt(string cipherTextBase64, string nonceBase64, string tagBase64, string keyBase64)
+    {
+        var key = Convert.FromBase64String(keyBase64);
+        var nonce = Convert.FromBase64String(nonceBase64);
+        var tag = Convert.FromBase64String(tagBase64);
+        var cipherBytes = Convert.FromBase64String(cipherTextBase64);
+        var plainBytes = new byte[cipherBytes.Length];
+
+        using var aes = new AesGcm(key, 16);
+        aes.Decrypt(nonce, cipherBytes, tag, plainBytes);
+
+        return Encoding.UTF8.GetString(plainBytes);
+    }
+}

RelayServer/Services/ChannelMessageService.cs

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+namespace RelayServer.Services;
+
+public class ChannelMessageService
+{
+    
+}

RelayServer/Services/CoreClientService.cs

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+namespace RelayServer.Services;
+
+public sealed class CoreClientService
+{
+    public Task<CoreUser?> GetUserByUsernameAsync(string username)
+    {
+        return Task.FromResult<CoreUser?>(username switch
+        {
+            "Keeper317" => new CoreUser("users:keeper317", "Keeper317", true),
+            "Ru_Kira" => new CoreUser("users:ru_kira", "Ru_Kira", true),
+            _ => null
+        });
+    }
+}
+
+public sealed record CoreUser(string Id, string Username, bool Licensed);

RelayServer/Services/ServerBootstrapService.cs

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+namespace RelayServer.Services;
+
+public class ServerBootstrapService
+{
+    
+}

RelayServer/Services/SurrealService.cs

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+using SurrealDb.Net;
+using SurrealDb.Net.Models.Auth;
+
+namespace RelayServer.Services;
+
+public sealed class SurrealService
+{
+    public async Task<SurrealDbClient> ConnectAsync()
+    {
+        var db = new SurrealDbClient("ws://127.0.0.1:8000/rpc");
+
+        await db.SignIn(new RootAuth
+        {
+            Username = "root",
+            Password = "secret"
+        });
+
+        await db.Use("test", "test");
+        return db;
+    }
+}