Implement IKeyManager

Akari.Prototype.Server/Services/KeyManager.cs

@@ -1,11 +1,117 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
+using System.Security.Cryptography;
 using System.Threading.Tasks;
+using Akari.Prototype.Server.Utils;
+using Microsoft.Extensions.Logging;
 
 namespace Akari.Prototype.Server.Services
 {
-    public class KeyManager : IKeyManager
+    public sealed class KeyManager : IKeyManager
     {
+        public const string KeysPath = "Keys";
+        public const int KeyLength = 256 / 8;
+
+        private readonly ILogger<KeyManager> _logger;
+        private readonly IMasterKeyService _masterKeyService;
+        private readonly AkariPath _akariPath;
+
+        public KeyManager(ILogger<KeyManager> logger, IMasterKeyService masterKeyService, AkariPath akariPath)
+        {
+            _logger = logger;
+            _masterKeyService = masterKeyService;
+            _akariPath = akariPath;
+
+            CheckConfig();
+        }
+
+        private void CheckConfig()
+        {
+            string path = _akariPath.GetPath(KeysPath);
+
+            if (!Directory.Exists(path))
+            {
+                Directory.CreateDirectory(path);
+            }
+        }
+
+        public bool AddFingerprint(string applicationName, string fingerprintName, AesGcm fingerprintKey)
+        {
+            if (!Directory.Exists(GetKeyDirectoryPath(applicationName)) || !_masterKeyService.TryGetKey(out var masterKey))
+            {
+                return false;
+            }
+
+            // Read key
+            var encryptedKeyBytes = File.ReadAllBytes(GetMasterKeyPath(applicationName));
+
+            var decryptedKeyBytes = Security.AesGcmDecrypt(masterKey, encryptedKeyBytes);
+
+            var newEncryptedKeyBytes = Security.AesGcmEncrypt(fingerprintKey, decryptedKeyBytes);
+
+            File.WriteAllBytes(GetKeyPath(applicationName, fingerprintName), newEncryptedKeyBytes);
+
+            _logger.LogDebug($"Fingerprint '{fingerprintName}' added for {applicationName}");
+
+            return true;
+        }
+
+        public void Clear(string applicationName)
+        {
+            _logger.LogDebug($"Deleted keys for {applicationName}");
+
+            _logger.LogDebug($"Going to delete {GetKeyDirectoryPath(applicationName)}");
+            //Directory.Delete(GetKeyDirectoryPath(applicationName));
+        }
+
+        public bool Create(string applicationName)
+        {
+            if (!_masterKeyService.TryGetKey(out var masterKey))
+            {
+                _logger.LogDebug("Can't create key if master not logged in");
+
+                return false;
+            }
+
+            Directory.CreateDirectory(GetKeyDirectoryPath(applicationName));
+
+            Span<byte> keyBytes = KeyLength <= 1024 ? stackalloc byte[KeyLength]
+                                                                 : new byte[KeyLength];
+
+            RandomNumberGenerator.Fill(keyBytes);
+
+            var encryptedKeyBytes = Security.AesGcmEncrypt(masterKey, keyBytes);
+
+            File.WriteAllBytes(GetMasterKeyPath(applicationName), encryptedKeyBytes);
+
+            _logger.LogDebug($"Key created for {applicationName}");
+
+            return true;
+        }
+
+        public AesGcm RetrieveKey(string applicationName, string fingerprintName, AesGcm fingerprintKey)
+        {
+            if (!Directory.Exists(GetKeyDirectoryPath(applicationName)))
+            {
+                throw new IOException($"Can't find key files for {applicationName}");
+            }
+
+            // Read key
+            var encryptedKeyBytes = File.ReadAllBytes(GetKeyPath(applicationName, fingerprintName));
+
+            var decryptedKeyBytes = Security.AesGcmDecrypt(fingerprintKey, encryptedKeyBytes);
+
+            _logger.LogDebug($"Key retrieved for {applicationName} using {fingerprintName}");
+
+            return new AesGcm(decryptedKeyBytes);
+        }
+
+        private string GetKeyDirectoryPath(string applicationName) => Path.Combine(_akariPath.GetPath(KeysPath), applicationName);
+
+        private string GetMasterKeyPath(string applicationName) => Path.Combine(GetKeyDirectoryPath(applicationName), "key");
+
+        private string GetKeyPath(string applicationName, string fingerprintName) => $"{GetMasterKeyPath(applicationName)}-{fingerprintName}";
     }
 }