Add FingerprintManager

Akari.Prototype.Server/Services/FingerprintManager.cs

@@ -0,0 +1,71 @@
+using Akari.Prototype.Server.Options;
+using Akari.Prototype.Server.Utils;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.Json;
+using System.Threading.Tasks;
+
+namespace Akari.Prototype.Server.Services
+{
+    public class FingerprintManager : IFingerprintManager
+    {
+        public const string FingerprintsPath = "fingerprints.json";
+
+        private readonly ILogger<FingerprintManager> _logger;
+        private readonly IOptions<AkariOptions> _akariOptions;
+        private readonly IAuthManager _authManager;
+
+        /// <summary>
+        /// Map token hash to user-friendly name
+        /// </summary>
+        private IDictionary<string, string> _fingerprintNames;
+
+        public FingerprintManager(ILogger<FingerprintManager> logger, IOptions<AkariOptions> akariOptions,
+                                    IAuthManager authManager)
+        {
+            _logger = logger;
+            _akariOptions = akariOptions;
+            _authManager = authManager;
+
+            LoadFingerprints();
+        }
+
+        private void LoadFingerprints()
+        {
+            var path = AkariPath.GetPath(FingerprintsPath);
+
+            // Create new
+            if (!File.Exists(path))
+            {
+                _fingerprintNames = new Dictionary<string, string>();
+
+                File.WriteAllText(path, JsonSerializer.Serialize(_fingerprintNames));
+            }
+            // Load
+            else
+            {
+                _fingerprintNames = JsonSerializer.Deserialize<IDictionary<string, string>>(File.ReadAllText(path));
+            }
+        }
+
+        public async Task VerifyToken(byte[] token)
+        {
+            var hash = Security.Argon2idHash(token);
+
+            _logger.LogDebug($"Verifying hash: {hash}");
+
+            if (!_fingerprintNames.TryGetValue(hash, out var name))
+            {
+                _logger.LogDebug($"Unknown hash, aborting: {hash}");
+
+                return;
+            }
+
+            _authManager.Auth(token, name);
+        }
+    }
+}