Add support for local (PLAINTEXT!) encryption key storage. Future commits will expand on this by allowing encrypted-at-rest storage of key material.

configs/codeplug.example.yml

@@ -1,7 +1,8 @@
 #
 # Digital Voice Modem - Desktop Dispatch Console
 #
-
+# Full path to local key YAML file (see keys.example.clear for formatting)
+#keyFile: "Full/Path/To/Keyfile.clear"
 #
 # FNE Masters
 #

configs/keys.example.clear

@@ -0,0 +1,15 @@
+keys:
+  -
+    # The key ID, in hex, for this key
+    keyId: 0x1
+    # The algorithm ID, in hex, for this key
+    algId: 0x84
+    # The key material, as a hex string representation, for this key
+    key: "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890ABCDEFGHIJKLMNOPQR"
+  -
+    # The key ID, in hex, for this key
+    keyId: 0x2
+    # The algorithm ID, in hex, for this key
+    algId: 0xAA
+    # The key material, as a hex string representation, for this key
+    key: "1234567890"

dvmconsole/Codeplug.cs

@@ -25,6 +25,10 @@ namespace dvmconsole
         ** Properties
         */
 
+        /// <summary>
+        /// The location of the YAML keyfile
+        /// </summary>
+        public string KeyFile { get; set; } = null;
         /// <summary>
         /// 
         /// </summary>

dvmconsole/KeyContainer.cs

@@ -0,0 +1,28 @@
+namespace dvmconsole;
+
+/// <summary>
+/// POCO which is used to decode a YML keyfile
+/// </summary>
+public class KeyContainer
+{
+    public List<KeyEntry> Keys { get; set; } = [];
+}
+
+public class KeyEntry
+{
+    public ushort KeyId { get; set; }
+    public int AlgId { get; set; }
+    public string Key { get; set; }
+
+    /// <summary>
+    /// Gets the contents of the Key property as a byte[]
+    /// </summary>
+    public byte[] KeyBytes => string.IsNullOrEmpty(Key) ? [] : StringToByteArray(Key);
+    
+    private static byte[] StringToByteArray(string hex) {
+        return Enumerable.Range(0, hex.Length)
+            .Where(x => x % 2 == 0)
+            .Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
+            .ToArray();
+    }
+}

dvmconsole/MainWindow.xaml.cs

@@ -559,7 +559,52 @@ namespace dvmconsole
                     // if the channel is configured for encryption request the key from the FNE
                     uint newTgid = uint.Parse(cpgChannel.Tgid);
                     if (cpgChannel.GetAlgoId() != 0 && cpgChannel.GetKeyId() != 0)
+                    {
                         fne.peer.SendMasterKeyRequest(cpgChannel.GetAlgoId(), cpgChannel.GetKeyId());
+                        if (Codeplug.KeyFile != null)
+                        {
+                            if (!File.Exists(Codeplug.KeyFile))
+                            {
+                                MessageBox.Show($"Key file {Codeplug.KeyFile} not found. {PLEASE_CHECK_CODEPLUG}", "Error", MessageBoxButton.OK, MessageBoxImage.Error);
+                            }
+                            else
+                            {
+                                var deserializer = new DeserializerBuilder()
+                                    .WithNamingConvention(CamelCaseNamingConvention.Instance)
+                                    .IgnoreUnmatchedProperties()
+                                    .Build();
+                                var keys = deserializer.Deserialize<KeyContainer>(File.ReadAllText(Codeplug.KeyFile));
+                                var KeysetItems = new Dictionary<int, KeysetItem>();
+
+                                foreach (var keyEntry in keys.Keys)
+                                {
+                                    var keyItem = new KeyItem();
+                                    keyItem.KeyId = keyEntry.KeyId;
+                                    var keyBytes = keyEntry.KeyBytes;
+                                    keyItem.SetKey(keyBytes,(uint)keyBytes.Length);
+                                    if (!KeysetItems.ContainsKey(keyEntry.AlgId))
+                                    {
+                                        var asByte = (byte)keyEntry.AlgId;
+                                        KeysetItems.Add(keyEntry.AlgId, new KeysetItem() { AlgId = asByte });
+                                    }
+
+
+                                    KeysetItems[keyEntry.AlgId].AddKey(keyItem);
+                                }
+                                foreach (var eventData in KeysetItems.Select(keyValuePair => keyValuePair.Value).Select(keysetItem => new KeyResponseEvent(0, new KmmModifyKey
+                                         {
+                                             AlgId = 0,
+                                             KeyId = 0,
+                                             MessageId = 0,
+                                             MessageLength = 0,
+                                             KeysetItem = keysetItem
+                                         }, [])))
+                                {
+                                    KeyResponseReceived(eventData);
+                                }
+                            }
+                        }
+                    }
                 }
             }
         }