add support for adding binaries, and correctly serialize them for kdbx 3 and 4.

example/pubspec.lock

@@ -132,6 +132,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.2.2"
+  matcher:
+    dependency: transitive
+    description:
+      name: matcher
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.12.6"
   meta:
     dependency: transitive
     description:
@@ -167,6 +174,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.3.1"
+  quiver:
+    dependency: transitive
+    description:
+      name: quiver
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.3"
   rxdart:
     dependency: transitive
     description:
@@ -186,6 +200,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.5.5"
+  stack_trace:
+    dependency: transitive
+    description:
+      name: stack_trace
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.9.3"
   string_scanner:
     dependency: transitive
     description:

lib/src/kdbx_binary.dart

@@ -2,6 +2,7 @@ import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
 
+import 'package:kdbx/src/internal/byte_utils.dart';
 import 'package:kdbx/src/kdbx_header.dart';
 import 'package:kdbx/src/kdbx_xml.dart';
 import 'package:meta/meta.dart';
@@ -24,6 +25,15 @@ class KdbxBinary {
     );
   }
 
+  InnerHeaderField writeToInnerHeader() {
+    final writer = WriterHelper();
+    final flags = isProtected ? 0x01 : 0x00;
+    writer.writeUint8(flags);
+    writer.writeBytes(value);
+    return InnerHeaderField(
+        InnerHeaderFields.Binary, writer.output.takeBytes());
+  }
+
   static KdbxBinary readBinaryXml(XmlElement valueNode,
       {@required bool isInline}) {
     assert(isInline != null);
@@ -39,4 +49,11 @@ class KdbxBinary {
       value: value,
     );
   }
+
+  void saveToXml(XmlElement valueNode) {
+    final content = base64.encode(gzip.encode(value));
+    valueNode.addAttributeBool(KdbxXml.ATTR_PROTECTED, isProtected);
+    valueNode.addAttributeBool(KdbxXml.ATTR_COMPRESSED, true);
+    valueNode.children.add(XmlText(content));
+  }
 }

lib/src/kdbx_entry.dart

@@ -1,3 +1,5 @@
+import 'dart:typed_data';
+
 import 'package:kdbx/kdbx.dart';
 import 'package:kdbx/src/crypto/protected_value.dart';
 import 'package:kdbx/src/kdbx_binary.dart';
@@ -8,6 +10,8 @@ import 'package:kdbx/src/kdbx_header.dart';
 import 'package:kdbx/src/kdbx_object.dart';
 import 'package:kdbx/src/kdbx_xml.dart';
 import 'package:logging/logging.dart';
+import 'package:meta/meta.dart';
+import 'package:path/path.dart' as path;
 import 'package:xml/xml.dart';
 
 final _logger = Logger('kdbx.kdbx_entry');
@@ -103,13 +107,12 @@ class KdbxEntry extends KdbxObject {
     final el = super.toXml();
     XmlUtils.removeChildrenByName(el, KdbxXml.NODE_STRING);
     XmlUtils.removeChildrenByName(el, KdbxXml.NODE_HISTORY);
-    el.children.removeWhere(
+    XmlUtils.removeChildrenByName(el, KdbxXml.NODE_BINARY);
-        (e) => e is XmlElement && e.name.local == KdbxXml.NODE_STRING);
     el.children.addAll(stringEntries.map((stringEntry) {
       final value = XmlElement(XmlName(KdbxXml.NODE_VALUE));
       if (stringEntry.value is ProtectedValue) {
-        value.attributes
+        value.attributes.add(
-            .add(XmlAttribute(XmlName(KdbxXml.ATTR_PROTECTED), 'True'));
+            XmlAttribute(XmlName(KdbxXml.ATTR_PROTECTED), KdbxXml.VALUE_TRUE));
         KdbxFile.setProtectedValueForNode(
             value, stringEntry.value as ProtectedValue);
       } else if (stringEntry.value is StringValue) {
@@ -122,6 +125,22 @@ class KdbxEntry extends KdbxObject {
           value,
         ]);
     }));
+    el.children.addAll(binaryEntries.map((binaryEntry) {
+      final key = binaryEntry.key;
+      final binary = binaryEntry.value;
+      final value = XmlElement(XmlName(KdbxXml.NODE_VALUE));
+      if (binary.isInline) {
+        binary.saveToXml(value);
+      } else {
+        final binaryIndex = file.ctx.findBinaryId(binary);
+        value.addAttribute(KdbxXml.ATTR_REF, binaryIndex.toString());
+      }
+      return XmlElement(XmlName(KdbxXml.NODE_BINARY))
+        ..children.addAll([
+          XmlElement(XmlName(KdbxXml.NODE_KEY))..children.add(XmlText(key.key)),
+          value,
+        ]);
+    }));
     if (!isHistoryEntry) {
       el.children.add(
         XmlElement(XmlName(KdbxXml.NODE_HISTORY))
@@ -177,6 +196,43 @@ class KdbxEntry extends KdbxObject {
 
   String get label => _plainValue(KdbxKey('Title'));
 
+  set label(String label) => setString(KdbxKey('Title'), PlainValue(label));
+
+  KdbxBinary createBinary({
+    @required bool isProtected,
+    @required String name,
+    @required Uint8List bytes,
+  }) {
+    assert(isProtected != null);
+    assert(bytes != null);
+    assert(name != null);
+    // make sure we don't have a path, just the file name.
+    final key = _uniqueBinaryName(path.basename(name));
+    final binary = KdbxBinary(
+      isInline: false,
+      isProtected: isProtected,
+      value: bytes,
+    );
+    file.ctx.addBinary(binary);
+    _binaries[key] = binary;
+    isDirty = true;
+    return binary;
+  }
+
+  KdbxKey _uniqueBinaryName(String fileName) {
+    final lastIndex = fileName.lastIndexOf('.');
+    final baseName =
+        lastIndex > -1 ? fileName.substring(0, lastIndex) : fileName;
+    final ext = lastIndex > -1 ? fileName.substring(lastIndex + 1) : 'ext';
+    for (var i = 0; i < 1000; i++) {
+      final k = i == 0 ? KdbxKey(fileName) : KdbxKey('$baseName$i.$ext');
+      if (!_binaries.containsKey(k)) {
+        return k;
+      }
+    }
+    throw StateError('Unable to find unique name for $fileName');
+  }
+
   @override
   String toString() {
     return 'KdbxGroup{uuid=$uuid,name=$label}';

lib/src/kdbx_format.dart

@@ -64,11 +64,15 @@ class KeyFileComposite implements Credentials {
 
 /// Context used during reading and writing.
 class KdbxReadWriteContext {
-  KdbxReadWriteContext({@required this.binaries, @required this.header})
+  KdbxReadWriteContext({
-      : assert(binaries != null),
+    @required List<KdbxBinary> binaries,
-        assert(header != null);
+    @required this.header,
+  })  : assert(binaries != null),
+        assert(header != null),
+        _binaries = binaries;
 
   static final kdbxContext = Expando<KdbxReadWriteContext>();
+
   static KdbxReadWriteContext kdbxContextForNode(xml.XmlParent node) {
     final ret = kdbxContext[node.document];
     if (ret == null) {
@@ -83,17 +87,36 @@ class KdbxReadWriteContext {
   }
 
   @protected
-  final List<KdbxBinary> binaries;
+  final List<KdbxBinary> _binaries;
+
+  Iterable<KdbxBinary> get binariesIterable => _binaries;
 
   final KdbxHeader header;
 
   int get versionMajor => header.versionMajor;
 
   KdbxBinary binaryById(int id) {
-    if (id >= binaries.length) {
+    if (id >= _binaries.length) {
       return null;
     }
-    return binaries[id];
+    return _binaries[id];
+  }
+
+  void addBinary(KdbxBinary binary) {
+    _binaries.add(binary);
+  }
+
+  /// finds the ID of the given binary.
+  /// if it can't be found, [KdbxCorruptedFileException] is thrown.
+  int findBinaryId(KdbxBinary binary) {
+    assert(binary != null);
+    assert(!binary.isInline);
+    final id = _binaries.indexOf(binary);
+    if (id < 0) {
+      throw KdbxCorruptedFileException('Unable to find binary.'
+          ' (${binary.value.length},${binary.isInline})');
+    }
+    return id;
   }
 }
 
@@ -191,6 +214,7 @@ class KdbxBody extends KdbxNode {
       ProtectedSaltGenerator saltGenerator, _KeysV4 keys) {
     final bodyWriter = WriterHelper();
     final xml = generateXml(saltGenerator);
+    kdbxFile.header.innerHeader.updateBinaries(kdbxFile.ctx.binariesIterable);
     kdbxFile.header.writeInnerHeader(bodyWriter);
     bodyWriter.writeBytes(utf8.encode(xml.toXmlString()) as Uint8List);
     final compressedBytes = (kdbxFile.header.compression == Compression.gzip
@@ -590,9 +614,9 @@ class KdbxFormat {
 
     final kdbxMeta = KdbxMeta.read(meta, ctx);
     if (kdbxMeta.binaries?.isNotEmpty == true) {
-      ctx.binaries.addAll(kdbxMeta.binaries);
+      ctx._binaries.addAll(kdbxMeta.binaries);
     } else if (header.innerHeader.binaries.isNotEmpty) {
-      ctx.binaries.addAll(header.innerHeader.binaries
+      ctx._binaries.addAll(header.innerHeader.binaries
           .map((e) => KdbxBinary.readBinaryInnerHeader(e)));
     }
 

lib/src/kdbx_header.dart

@@ -5,10 +5,11 @@ import 'package:crypto/crypto.dart' as crypto;
 import 'package:kdbx/src/crypto/key_encrypter_kdf.dart';
 import 'package:kdbx/src/internal/byte_utils.dart';
 import 'package:kdbx/src/internal/consts.dart';
+import 'package:kdbx/src/kdbx_binary.dart';
 import 'package:kdbx/src/kdbx_var_dictionary.dart';
+import 'package:kdbx/src/utils/scope_functions.dart';
 import 'package:logging/logging.dart';
 import 'package:meta/meta.dart';
-import 'package:kdbx/src/utils/scope_functions.dart';
 
 final _logger = Logger('kdbx.header');
 
@@ -224,6 +225,7 @@ class KdbxHeader {
   }
 
   void writeInnerHeader(WriterHelper writer) {
+    assert(versionMajor >= 4);
     _validateInner();
     for (final field in InnerHeaderFields.values
         .where((f) => f != InnerHeaderFields.EndOfHeader)) {
@@ -541,4 +543,9 @@ class InnerHeader {
     binaries.clear();
     binaries.addAll(other.binaries);
   }
+
+  void updateBinaries(Iterable<KdbxBinary> newBinaries) {
+    binaries.clear();
+    binaries.addAll(newBinaries.map((binary) => binary.writeToInnerHeader()));
+  }
 }

lib/src/kdbx_meta.dart

@@ -6,7 +6,9 @@ import 'package:kdbx/src/kdbx_header.dart';
 import 'package:kdbx/src/kdbx_object.dart';
 import 'package:kdbx/src/kdbx_xml.dart';
 import 'package:meta/meta.dart';
+import 'package:quiver/iterables.dart';
 import 'package:xml/xml.dart' as xml;
+import 'package:xml/xml.dart';
 
 class KdbxMeta extends KdbxNode implements KdbxNodeContext {
   KdbxMeta.create({
@@ -61,5 +63,23 @@ class KdbxMeta extends KdbxNode implements KdbxNodeContext {
       DateTimeUtcNode(this, 'RecycleBinChanged');
 
   @override
-  xml.XmlElement toXml() => super.toXml()..replaceSingle(customData.toXml());
+  xml.XmlElement toXml() {
+    final ret = super.toXml()..replaceSingle(customData.toXml());
+    XmlUtils.removeChildrenByName(ret, KdbxXml.NODE_BINARIES);
+    // with kdbx >= 4 we assume the binaries were already written in the header.
+    if (ctx.versionMajor < 4) {
+      ret.children.add(
+        XmlElement(XmlName(KdbxXml.NODE_BINARIES))
+          ..children.addAll(
+            enumerate(ctx.binariesIterable).map((indexed) {
+              final xmlBinary = XmlUtils.createNode(KdbxXml.NODE_BINARY)
+                ..addAttribute(KdbxXml.ATTR_ID, indexed.index.toString());
+              indexed.value.saveToXml(xmlBinary);
+              return xmlBinary;
+            }),
+          ),
+      );
+    }
+    return ret;
+  }
 }

lib/src/kdbx_xml.dart

@@ -21,11 +21,20 @@ class KdbxXml {
   static const ATTR_REF = 'Ref';
 
   static const NODE_CUSTOM_DATA_ITEM = 'Item';
+
+  static const String VALUE_TRUE = 'True';
+  static const String VALUE_FALSE = 'False';
 }
 
 extension XmlElementKdbx on XmlElement {
   bool getAttributeBool(String name) =>
       getAttribute(name)?.toLowerCase() == 'true';
+
+  void addAttribute(String name, String value) =>
+      attributes.add(XmlAttribute(XmlName(name), value));
+
+  void addAttributeBool(String name, bool value) =>
+      addAttribute(name, value ? KdbxXml.VALUE_TRUE : KdbxXml.VALUE_FALSE);
 }
 
 abstract class KdbxSubNode<T> {

pubspec.yaml

@@ -20,6 +20,8 @@ dependencies:
   clock: '>=1.0.0 <2.0.0'
   convert: '>=2.0.0 <3.0.0'
   isolate: '>=2.0.3 <3.0.0'
+  path: '>=1.6.0 <2.0.0'
+  quiver: '>=2.1.0 <3.0.0'
 
   collection: '>=1.14.0 <2.0.0'
 

test/kdbx_binaries_test.dart

@@ -16,6 +16,37 @@ void expectBinary(KdbxEntry entry, String key, dynamic matcher) {
   expect(binary.value.value, matcher);
 }
 
+Future<void> _testAddNewAttachment(String filePath) async {
+  final saved = await (() async {
+    final f = await TestUtil.readKdbxFile(filePath);
+    final entry = KdbxEntry.create(f, f.body.rootGroup);
+    entry.label = 'addattachment';
+    f.body.rootGroup.addEntry(entry);
+    expect(entry.binaryEntries, hasLength(0));
+    entry.createBinary(
+        isProtected: false,
+        name: 'test.txt',
+        bytes: utf8.encode('Content1') as Uint8List);
+    entry.createBinary(
+        isProtected: false,
+        name: 'test.txt',
+        bytes: utf8.encode('Content2') as Uint8List);
+    return await f.save();
+  })();
+  {
+    final file = await TestUtil.readKdbxFileBytes(saved);
+    final entry = file.body.rootGroup.entries
+        .firstWhere((e) => e.label == 'addattachment');
+    final binaries = entry.binaryEntries.toList();
+    expect(entry.binaryEntries, hasLength(2));
+    expect(binaries[0].key.key, 'test.txt');
+    expect(binaries[0].value.value, IsUtf8String('Content1'));
+    // must have been renamed.
+    expect(binaries[1].key.key, 'test1.txt');
+    expect(binaries[1].value.value, IsUtf8String('Content2'));
+  }
+}
+
 void main() {
   Logger.root.level = Level.ALL;
   PrintAppender().attachToLogger(Logger.root);
@@ -54,6 +85,9 @@ void main() {
       final entry = file.body.rootGroup.entries.first;
       expectKeepass2binariesContents(entry);
     });
+    test('Add new attachment', () async {
+      await _testAddNewAttachment('test/keepass2binaries.kdbx');
+    });
   });
   group('kdbx4 attachment', () {
     test('read binary', () async {
@@ -66,8 +100,7 @@ void main() {
       expectBinary(file.body.rootGroup.entries.last, 'keepasslogo.jpeg',
           hasLength(7092));
     });
-  });
+    test('read, write, read kdbx4', () async {
-  test('read, write, read', () async {
       final fileRead =
           await TestUtil.readKdbxFile('test/keepass2kdbx4binaries.kdbx');
       final saved = await fileRead.save();
@@ -75,8 +108,12 @@ void main() {
       expect(file.body.rootGroup.entries, hasLength(2));
       expectBinary(file.body.rootGroup.entries.first, 'example2.txt',
           IsUtf8String('content2 example\n\n'));
-    expectBinary(
+      expectBinary(file.body.rootGroup.entries.last, 'keepasslogo.jpeg',
-        file.body.rootGroup.entries.last, 'keepasslogo.jpeg', hasLength(7092));
+          hasLength(7092));
+    });
+    test('Add new attachment kdbx4', () async {
+      await _testAddNewAttachment('test/keepass2kdbx4binaries.kdbx');
+    });
   });
 }