WIP

Signed-off-by: Nguyen Van Nguyen <[email protected]>
web-of-trust · Dec 10, 2024 · 0f6c902 · 0f6c902
1 parent 49e8fad
commit 0f6c902
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Showing 4 changed files with 55 additions and 9 deletions.
diff --git a/lib/src/key/base_key.dart b/lib/src/key/base_key.dart
@@ -145,6 +145,20 @@ abstract class BaseKey implements KeyInterface {
     return [];
   }
 
+  @override
+  preferredAeads([
+    final SymmetricAlgorithm symmetric = SymmetricAlgorithm.aes128,
+  ]) {
+    for (final signature in directSignatures) {
+      final subpacket = signature.getSubpacket<PreferredAeadCiphers>();
+      final aeads = subpacket?.preferredAeads(symmetric) ?? [];
+      if (aeads.isNotEmpty) {
+        return aeads;
+      }
+    }
+    return [];
+  }
+
   @override
   isPreferredAeadCiphers([
     final SymmetricAlgorithm symmetric = SymmetricAlgorithm.aes128,

diff --git a/lib/src/message/literal_message.dart b/lib/src/message/literal_message.dart
@@ -63,18 +63,18 @@ final class LiteralMessage extends BaseMessage implements LiteralMessageInterfac
     var aeadProtect = Config.aeadProtect;
     final aead = Config.preferredAead;
     for (final key in encryptionKeys) {
+      final symmetrics = key.preferredSymmetrics;
+      if (symmetrics.isNotEmpty && !symmetrics.contains(symmetric)) {
+        throw AssertionError(
+          'Symmetric not compatible with the given `encryptionKeys`',
+        );
+      }
       if (key.aeadSupported) {
-        if (!key.isPreferredAeadCiphers(symmetric, aead)) {
-          throw AssertionError(
-            'Aead ciphers not compatible with the given `encryptionKeys`',
-          );
+        final aeads = key.preferredAeads(symmetric);
+        if (!aeads.contains(aead)) {
+          aeadProtect = false;
         }
       } else {
-        if (key.preferredSymmetrics.isNotEmpty && !key.preferredSymmetrics.contains(symmetric)) {
-          throw AssertionError(
-            'Symmetric not compatible with the given `encryptionKeys`',
-          );
-        }
         aeadProtect = false;
       }
     }
@@ -203,6 +203,7 @@ final class LiteralMessage extends BaseMessage implements LiteralMessageInterfac
       ).packets,
     ];
     var index = 0;
+
     /// innermost OPS refers to the first signature packet
     final opsPackets = signaturePackets
         .map((packet) {

diff --git a/lib/src/packet/signature/preferred_aead_ciphers.dart b/lib/src/packet/signature/preferred_aead_ciphers.dart
@@ -23,6 +23,32 @@ class PreferredAeadCiphers extends SignatureSubpacket {
           data,
         );
 
+  List<AeadAlgorithm> preferredAeads(
+    final SymmetricAlgorithm symmetric,
+  ) {
+    final aeads = <AeadAlgorithm>[];
+    if (data.isNotEmpty) {
+      const chunkSize = 2;
+      var data = this.data;
+      while (data.isNotEmpty) {
+        final size = chunkSize < data.length ? chunkSize : data.length;
+        final ciphers = data.sublist(0, size);
+        if (ciphers.elementAtOrNull(1) != null) {
+          final preferredSymmetric = SymmetricAlgorithm.values.firstWhere(
+            (alg) => alg.value == ciphers.elementAt(0),
+          );
+          if (symmetric == preferredSymmetric) {
+            aeads.add(AeadAlgorithm.values.firstWhere(
+              (alg) => alg.value == ciphers.elementAt(1),
+            ));
+          }
+        }
+        data = data.sublist(size);
+      }
+    }
+    return aeads;
+  }
+
   bool isPreferred(
     final SymmetricAlgorithm symmetric,
     final AeadAlgorithm aead,

diff --git a/lib/src/type/key.dart b/lib/src/type/key.dart
@@ -69,6 +69,11 @@ abstract interface class KeyInterface implements ArmorableInterface, PacketConta
   /// Get subkeys
   List<SubkeyInterface> get subkeys;
 
+  /// Return preferred aead algorithms
+  List<AeadAlgorithm> preferredAeads([
+    final SymmetricAlgorithm symmetric = SymmetricAlgorithm.aes128,
+  ]);
+
   /// Return aead ciphers is preferred
   bool isPreferredAeadCiphers([
     final SymmetricAlgorithm symmetric = SymmetricAlgorithm.aes128,