release: Bump version to 0.2.0

This reverts commit fafc4f2320.

.gitignore

@@ -12,3 +12,6 @@ pubspec.lock
 # NixOS
 .direnv
 .envrc
+
+# Protobuf build artifacts
+lib/protobuf/*.dart

.gitlint

@@ -5,6 +5,6 @@ line-length=72
 [title-trailing-punctuation]
 [title-hard-tab]
 [title-match-regex]
-regex=^(feat|fix|test|release|chore|security|docs|refactor):.*$
+regex=^(feat|fix|test|release|chore|security|docs|refactor|style):.*$
 [body-trailing-whitespace]
 [body-first-line-empty]

CHANGELOG.md

@@ -1,3 +1,17 @@
-## 1.0.0
+## 0.1.0
 
-- Initial version.
+- Initial version
+- Implement the Double Ratchet, X3DH and OMEMO specific bits
+- Add a Blind-Trust-Before-Verification TrustManager
+- Supported OMEMO version: 0.8.3
+
+## 0.1.3
+
+- Fix bug with the Double Ratchet causing only the initial message to be decryptable
+- Expose `getDeviceMap` as a developer usable function
+
+## 0.2.0
+
+- Add convenience functions `getDeviceId` and `getDeviceBundle`
+- Creating a new ratchet with an id for which we already have a ratchet will now overwrite the old ratchet
+- Ratchet now carry an "acknowledged" attribute

README.md

@@ -18,11 +18,32 @@ the stanza format of your preferred XMPP library yourself.
 - **Please note that this library has not been audited for its security! Use at your own risk!**
 - This library is not tested with other implementations of OMEMO 0.8.3 as I do not know of any client implementing spec compliant OMEMO 0.8.3. It does, however, work with itself.
 
+## Usage
+
+Include `omemo_dart` in your `pubspec.yaml` like this:
+
+```yaml
+# [...]
+
+dependencies:
+  omemo_dart:
+    hosted: https://git.polynom.me/api/packages/PapaTutuWawa/pub
+    version: ^0.1.0
+  # [...]
+
+# [...]
+```
+
 ## Contributing
 
 Due to issues with `protobuf`, `omemo_dart` reimplements the Protobuf encoding for the required
 OMEMO messages. As such, `protobuf` is only a dependency for testing that the serialisation and
-deserialisation of the custom implementation.
+deserialisation of the custom implementation. In order to run tests, you need the Protbuf
+compiler. After that, making sure that
+the [Dart Protobuf compiler addon](https://pub.dev/packages/protoc_plugin) and the
+Protobuf compiler itself is in your PATH,
+run `protoc -I=./protobuf/ --dart_out=lib/protobuf/ ./protobuf/schema.proto` in the
+repository's root to generate the real Protobuf bindings.
 
 When submitting a PR, please run the linter using `dart analyze` and make sure that all
 tests still pass using `dart test`.

example/omemo_dart_example.dart

@@ -1,5 +1,155 @@
-//import 'package:omemo_dart/omemo_dart.dart';
+import 'dart:convert';
+import 'package:omemo_dart/omemo_dart.dart';
 
-void main() {
-  // TODO(PapaTutuWawa): Currently NOOP
+/// This example aims to demonstrate how omemo_dart is used. Since omemo_dart is not
+/// dependent on any XMPP library, you need to convert stanzas to the appropriate
+/// intermediary format and back.
+void main() async {
+  const aliceJid = 'alice@some.server';
+  const bobJid = 'bob@other.serve';
+
+  // You are Alice and want to begin using OMEMO, so you first create a SessionManager
+  final aliceSession = await OmemoSessionManager.generateNewIdentity(
+    // The bare Jid of Alice as a String
+    aliceJid,
+    // The trust manager we want to use. In this case, we use the provided one that
+    // implements "Blind Trust Before Verification". To make things simpler, we keep
+    // no persistent data and can thus use the MemoryBTBVTrustManager. If we wanted to keep
+    // the state, we would have to override BlindTrustBeforeVerificationTrustManager.
+    MemoryBTBVTrustManager(),
+    // Here we specify how many Onetime Prekeys we want to have. XEP-0384 recommends around
+    // 100 OPKs, so let's generate 100. The parameter defaults to 100.
+    //opkAmount: 100,
+  );
+
+  // Alice now wants to chat with Bob at his bare Jid "bob@other.server". To make things
+  // simple, we just generate the identity bundle ourselves. In the real world, we would
+  // request it using PEP and then convert the device bundle into a OmemoBundle object.
+  final bobSession = await OmemoSessionManager.generateNewIdentity(
+    bobJid,
+    MemoryBTBVTrustManager(),
+    // Just for illustrative purposes
+    opkAmount: 1,
+  );
+
+  // Alice prepares to send the message to Bob, so she builds the message stanza and
+  // collects all the children of the stanza that should be encrypted into a string.
+  const aliceMessageStanzaBody = '''
+  <body>Hello Bob, it's me, Alice!</body>
+  <super-secret-element xmlns='super-secret-element' />
+  ''';
+
+  // Since OMEMO 0.8.3 mandates usage of XEP-0420: Stanza Content Encryption, we have to
+  // wrap our acual payload - aliceMessageStanzaBody - into an SCE envelope. Note that
+  // the rpad element must contain a random string. See XEP-0420 for recommendations.
+  // OMEMO makes the <time /> element optional, but let's use for this example.
+  const envelope = '''
+<envelope xmlns='urn:xmpp:sce:1'>
+  <content>
+    $aliceMessageStanzaBody
+  </content>
+  <rpad>s0m3-r4nd0m-b9t3s</rpad>
+  <from jid='$aliceJid' />
+  <time stamp='1969-07-20T21:56:15-05:00' />
+</envelope>
+''';
+ 
+  // Since Alice has no open session with Bob, we need to tell the session manager to build
+  // it when sending the message.
+  final message = await aliceSession.encryptToJid(
+    // The bare receiver Jid
+    bobJid,
+    // The envelope we want to encrypt
+    envelope,
+    // Since this is the first time Alice contacts Bob from this device, we need to create
+    // a new session. Let's also assume that Bob only has one device. We may, however,
+    // add more bundles to newSessions, if we know of more.
+    newSessions: [
+      await bobSession.getDeviceBundle(),
+    ],
+  );
+
+  // Alice now builds the actual message stanza for Bob
+  final payload = base64.encode(message.ciphertext!);
+  final aliceDevice = await aliceSession.getDevice();
+  // ignore: unused_local_variable
+  final bobDevice = await bobSession.getDevice();
+  // Since we know we have just one key for Bob, we take a shortcut. However, in the real
+  // world, we have to serialise every EncryptedKey to a <key /> element and group them
+  // per Jid.
+  final key = message.encryptedKeys[0];
+
+  // Note that the key's "kex" attribute refers to key.kex. It just means that the
+  // encrypted key also contains the required data for Bob to build a session with Alice.
+  // ignore: unused_local_variable
+  final aliceStanza = '''
+<message from='$aliceJid/device1' to='$bobJid/device2'>
+  <encrypted xmlns='urn:xmpp:omemo:2'>
+    <header sid='${aliceDevice.id}'>
+      <keys jid='$bobJid'>
+        <key rid='${key.rid} kex='true'>
+          ${key.value}
+        </key>
+      </keys>
+    </header>
+    <payload>
+      $payload
+    </payload>
+  </encrypted>
+</message>
+''';
+
+  // Alice can now send this message to Bob using our preferred XMPP library.
+  // ...
+
+  // Bob now receives an OMEMO encrypted message from Alice and wants to decrypt it.
+  // Since we have just one key, let's just deserialise the one key by hand.
+  final keys = [
+    EncryptedKey(bobJid, key.rid, key.value, true),
+  ];
+
+  // Bob extracts the payload and attempts to decrypt it.
+  // ignore: unused_local_variable
+  final bobMessage = await bobSession.decryptMessage(
+    // base64 decode the payload
+    base64.decode(payload),
+    // Specify the Jid of the sender
+    aliceJid,
+    // Specify the device identifier of the sender (the "sid" attribute of <header />)
+    aliceDevice.id,
+    // The deserialised keys
+    keys,
+  );
+
+  // All Bob has to do now is replace the OMEMO wrapper element 
+  // <encrypted xmlns='urn:xmpp:omemo:2' />) with the content of the <content /> element
+  // of the envelope we just decrypted.
+
+  // Bob now has a session with Alice and can send encrypted message to her.
+  // Since they both used the BlindTrustBeforeVerificationTrustManager, they currently
+  // use blind trust, meaning that both Alice and Bob accept new devices without any
+  // hesitation. If Alice, however, decides to verify one of Bob's devices and sets
+  // it as verified using
+  // ```
+  // await aliceSession.trustManager.setDeviceTrust(bobJid, bobDevice.id, BTBVTrustState.verified)
+  // ```
+  // then Alice's OmemoSessionManager won't encrypt to new devices unless they are also
+  // verified. To prevent user confusion, you should check if every device is trusted
+  // before sending the message and ask the user for a trust decision.
+  // If you want to make the BlindTrustBeforeVerificationTrustManager persistent, then
+  // you need to subclass it and override the `Future<void> commitState()` and
+  // `Future<void> loadState()` functions. commitState is called everytime the internal
+  // state gets changed. loadState never gets automatically called but is more of a
+  // function for the user to restore the trust manager. In those functions you have
+  // access to `ratchetMap`, which maps a `RatchetMapKey` - essentially a tuple consisting
+  // of a bare Jid and the device identifier - to the trust state, and `devices` which
+  // maps a bare Jid to its device identifiers.
+  // To make the entire OmemoSessionManager persistent, you have two options:
+  // - use the provided `toJson()` and `fromJson()` functions. They, however, serialise
+  //   and deserialise *ALL* known sessions, so it might be slow.
+  // - subscribe to the session manager's `eventStream`. There, events get triggered
+  //   everytime a ratchet changes, our own device changes or the internal ratchet map
+  //   gets changed. This give finer control over the the serialisation. The session
+  //   manager can then be restored using its constructor. For a list of events, see
+  //   lib/src/omemo/events.dart.
 }

lib/omemo_dart.dart

@@ -2,14 +2,15 @@ library omemo_dart;
 
 export 'src/double_ratchet/double_ratchet.dart';
 export 'src/errors.dart';
-export 'src/events.dart';
 export 'src/helpers.dart';
 export 'src/keys.dart';
 export 'src/omemo/bundle.dart';
 export 'src/omemo/device.dart';
 export 'src/omemo/encrypted_key.dart';
 export 'src/omemo/encryption_result.dart';
+export 'src/omemo/events.dart';
 export 'src/omemo/fingerprint.dart';
+export 'src/omemo/ratchet_map_key.dart';
 export 'src/omemo/sessionmanager.dart';
 export 'src/trust/base.dart';
 export 'src/trust/btbv.dart';

lib/protobuf/schema.pb.dart

@@ -1,263 +0,0 @@
-///
-//  Generated code. Do not modify.
-//  source: schema.proto
-//
-// @dart = 2.12
-// ignore_for_file: annotate_overrides,camel_case_types,constant_identifier_names,directives_ordering,library_prefixes,non_constant_identifier_names,prefer_final_fields,return_of_invalid_type,unnecessary_const,unnecessary_import,unnecessary_this,unused_import,unused_shown_name
-
-import 'dart:core' as $core;
-
-import 'package:protobuf/protobuf.dart' as $pb;
-
-class OMEMOMessage extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i = $pb.BuilderInfo(const $core.bool.fromEnvironment('protobuf.omit_message_names') ? '' : 'OMEMOMessage', createEmptyInstance: create)
-    ..a<$core.int>(1, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'n', $pb.PbFieldType.QU3)
-    ..a<$core.int>(2, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'pn', $pb.PbFieldType.QU3)
-    ..a<$core.List<$core.int>>(3, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'dhPub', $pb.PbFieldType.QY)
-    ..a<$core.List<$core.int>>(4, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'ciphertext', $pb.PbFieldType.OY)
-  ;
-
-  OMEMOMessage._() : super();
-  factory OMEMOMessage({
-    $core.int? n,
-    $core.int? pn,
-    $core.List<$core.int>? dhPub,
-    $core.List<$core.int>? ciphertext,
-  }) {
-    final _result = create();
-    if (n != null) {
-      _result.n = n;
-    }
-    if (pn != null) {
-      _result.pn = pn;
-    }
-    if (dhPub != null) {
-      _result.dhPub = dhPub;
-    }
-    if (ciphertext != null) {
-      _result.ciphertext = ciphertext;
-    }
-    return _result;
-  }
-  factory OMEMOMessage.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
-  factory OMEMOMessage.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
-  @$core.Deprecated(
-  'Using this can add significant overhead to your binary. '
-  'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
-  'Will be removed in next major version')
-  OMEMOMessage clone() => OMEMOMessage()..mergeFromMessage(this);
-  @$core.Deprecated(
-  'Using this can add significant overhead to your binary. '
-  'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
-  'Will be removed in next major version')
-  OMEMOMessage copyWith(void Function(OMEMOMessage) updates) => super.copyWith((message) => updates(message as OMEMOMessage)) as OMEMOMessage; // ignore: deprecated_member_use
-  $pb.BuilderInfo get info_ => _i;
-  @$core.pragma('dart2js:noInline')
-  static OMEMOMessage create() => OMEMOMessage._();
-  OMEMOMessage createEmptyInstance() => create();
-  static $pb.PbList<OMEMOMessage> createRepeated() => $pb.PbList<OMEMOMessage>();
-  @$core.pragma('dart2js:noInline')
-  static OMEMOMessage getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<OMEMOMessage>(create);
-  static OMEMOMessage? _defaultInstance;
-
-  @$pb.TagNumber(1)
-  $core.int get n => $_getIZ(0);
-  @$pb.TagNumber(1)
-  set n($core.int v) { $_setUnsignedInt32(0, v); }
-  @$pb.TagNumber(1)
-  $core.bool hasN() => $_has(0);
-  @$pb.TagNumber(1)
-  void clearN() => clearField(1);
-
-  @$pb.TagNumber(2)
-  $core.int get pn => $_getIZ(1);
-  @$pb.TagNumber(2)
-  set pn($core.int v) { $_setUnsignedInt32(1, v); }
-  @$pb.TagNumber(2)
-  $core.bool hasPn() => $_has(1);
-  @$pb.TagNumber(2)
-  void clearPn() => clearField(2);
-
-  @$pb.TagNumber(3)
-  $core.List<$core.int> get dhPub => $_getN(2);
-  @$pb.TagNumber(3)
-  set dhPub($core.List<$core.int> v) { $_setBytes(2, v); }
-  @$pb.TagNumber(3)
-  $core.bool hasDhPub() => $_has(2);
-  @$pb.TagNumber(3)
-  void clearDhPub() => clearField(3);
-
-  @$pb.TagNumber(4)
-  $core.List<$core.int> get ciphertext => $_getN(3);
-  @$pb.TagNumber(4)
-  set ciphertext($core.List<$core.int> v) { $_setBytes(3, v); }
-  @$pb.TagNumber(4)
-  $core.bool hasCiphertext() => $_has(3);
-  @$pb.TagNumber(4)
-  void clearCiphertext() => clearField(4);
-}
-
-class OMEMOAuthenticatedMessage extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i = $pb.BuilderInfo(const $core.bool.fromEnvironment('protobuf.omit_message_names') ? '' : 'OMEMOAuthenticatedMessage', createEmptyInstance: create)
-    ..a<$core.List<$core.int>>(1, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'mac', $pb.PbFieldType.QY)
-    ..a<$core.List<$core.int>>(2, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'message', $pb.PbFieldType.QY)
-  ;
-
-  OMEMOAuthenticatedMessage._() : super();
-  factory OMEMOAuthenticatedMessage({
-    $core.List<$core.int>? mac,
-    $core.List<$core.int>? message,
-  }) {
-    final _result = create();
-    if (mac != null) {
-      _result.mac = mac;
-    }
-    if (message != null) {
-      _result.message = message;
-    }
-    return _result;
-  }
-  factory OMEMOAuthenticatedMessage.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
-  factory OMEMOAuthenticatedMessage.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
-  @$core.Deprecated(
-  'Using this can add significant overhead to your binary. '
-  'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
-  'Will be removed in next major version')
-  OMEMOAuthenticatedMessage clone() => OMEMOAuthenticatedMessage()..mergeFromMessage(this);
-  @$core.Deprecated(
-  'Using this can add significant overhead to your binary. '
-  'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
-  'Will be removed in next major version')
-  OMEMOAuthenticatedMessage copyWith(void Function(OMEMOAuthenticatedMessage) updates) => super.copyWith((message) => updates(message as OMEMOAuthenticatedMessage)) as OMEMOAuthenticatedMessage; // ignore: deprecated_member_use
-  $pb.BuilderInfo get info_ => _i;
-  @$core.pragma('dart2js:noInline')
-  static OMEMOAuthenticatedMessage create() => OMEMOAuthenticatedMessage._();
-  OMEMOAuthenticatedMessage createEmptyInstance() => create();
-  static $pb.PbList<OMEMOAuthenticatedMessage> createRepeated() => $pb.PbList<OMEMOAuthenticatedMessage>();
-  @$core.pragma('dart2js:noInline')
-  static OMEMOAuthenticatedMessage getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<OMEMOAuthenticatedMessage>(create);
-  static OMEMOAuthenticatedMessage? _defaultInstance;
-
-  @$pb.TagNumber(1)
-  $core.List<$core.int> get mac => $_getN(0);
-  @$pb.TagNumber(1)
-  set mac($core.List<$core.int> v) { $_setBytes(0, v); }
-  @$pb.TagNumber(1)
-  $core.bool hasMac() => $_has(0);
-  @$pb.TagNumber(1)
-  void clearMac() => clearField(1);
-
-  @$pb.TagNumber(2)
-  $core.List<$core.int> get message => $_getN(1);
-  @$pb.TagNumber(2)
-  set message($core.List<$core.int> v) { $_setBytes(1, v); }
-  @$pb.TagNumber(2)
-  $core.bool hasMessage() => $_has(1);
-  @$pb.TagNumber(2)
-  void clearMessage() => clearField(2);
-}
-
-class OMEMOKeyExchange extends $pb.GeneratedMessage {
-  static final $pb.BuilderInfo _i = $pb.BuilderInfo(const $core.bool.fromEnvironment('protobuf.omit_message_names') ? '' : 'OMEMOKeyExchange', createEmptyInstance: create)
-    ..a<$core.int>(1, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'pkId', $pb.PbFieldType.QU3)
-    ..a<$core.int>(2, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'spkId', $pb.PbFieldType.QU3)
-    ..a<$core.List<$core.int>>(3, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'ik', $pb.PbFieldType.QY)
-    ..a<$core.List<$core.int>>(4, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'ek', $pb.PbFieldType.QY)
-    ..aQM<OMEMOAuthenticatedMessage>(5, const $core.bool.fromEnvironment('protobuf.omit_field_names') ? '' : 'message', subBuilder: OMEMOAuthenticatedMessage.create)
-  ;
-
-  OMEMOKeyExchange._() : super();
-  factory OMEMOKeyExchange({
-    $core.int? pkId,
-    $core.int? spkId,
-    $core.List<$core.int>? ik,
-    $core.List<$core.int>? ek,
-    OMEMOAuthenticatedMessage? message,
-  }) {
-    final _result = create();
-    if (pkId != null) {
-      _result.pkId = pkId;
-    }
-    if (spkId != null) {
-      _result.spkId = spkId;
-    }
-    if (ik != null) {
-      _result.ik = ik;
-    }
-    if (ek != null) {
-      _result.ek = ek;
-    }
-    if (message != null) {
-      _result.message = message;
-    }
-    return _result;
-  }
-  factory OMEMOKeyExchange.fromBuffer($core.List<$core.int> i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromBuffer(i, r);
-  factory OMEMOKeyExchange.fromJson($core.String i, [$pb.ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY]) => create()..mergeFromJson(i, r);
-  @$core.Deprecated(
-  'Using this can add significant overhead to your binary. '
-  'Use [GeneratedMessageGenericExtensions.deepCopy] instead. '
-  'Will be removed in next major version')
-  OMEMOKeyExchange clone() => OMEMOKeyExchange()..mergeFromMessage(this);
-  @$core.Deprecated(
-  'Using this can add significant overhead to your binary. '
-  'Use [GeneratedMessageGenericExtensions.rebuild] instead. '
-  'Will be removed in next major version')
-  OMEMOKeyExchange copyWith(void Function(OMEMOKeyExchange) updates) => super.copyWith((message) => updates(message as OMEMOKeyExchange)) as OMEMOKeyExchange; // ignore: deprecated_member_use
-  $pb.BuilderInfo get info_ => _i;
-  @$core.pragma('dart2js:noInline')
-  static OMEMOKeyExchange create() => OMEMOKeyExchange._();
-  OMEMOKeyExchange createEmptyInstance() => create();
-  static $pb.PbList<OMEMOKeyExchange> createRepeated() => $pb.PbList<OMEMOKeyExchange>();
-  @$core.pragma('dart2js:noInline')
-  static OMEMOKeyExchange getDefault() => _defaultInstance ??= $pb.GeneratedMessage.$_defaultFor<OMEMOKeyExchange>(create);
-  static OMEMOKeyExchange? _defaultInstance;
-
-  @$pb.TagNumber(1)
-  $core.int get pkId => $_getIZ(0);
-  @$pb.TagNumber(1)
-  set pkId($core.int v) { $_setUnsignedInt32(0, v); }
-  @$pb.TagNumber(1)
-  $core.bool hasPkId() => $_has(0);
-  @$pb.TagNumber(1)
-  void clearPkId() => clearField(1);
-
-  @$pb.TagNumber(2)
-  $core.int get spkId => $_getIZ(1);
-  @$pb.TagNumber(2)
-  set spkId($core.int v) { $_setUnsignedInt32(1, v); }
-  @$pb.TagNumber(2)
-  $core.bool hasSpkId() => $_has(1);
-  @$pb.TagNumber(2)
-  void clearSpkId() => clearField(2);
-
-  @$pb.TagNumber(3)
-  $core.List<$core.int> get ik => $_getN(2);
-  @$pb.TagNumber(3)
-  set ik($core.List<$core.int> v) { $_setBytes(2, v); }
-  @$pb.TagNumber(3)
-  $core.bool hasIk() => $_has(2);
-  @$pb.TagNumber(3)
-  void clearIk() => clearField(3);
-
-  @$pb.TagNumber(4)
-  $core.List<$core.int> get ek => $_getN(3);
-  @$pb.TagNumber(4)
-  set ek($core.List<$core.int> v) { $_setBytes(3, v); }
-  @$pb.TagNumber(4)
-  $core.bool hasEk() => $_has(3);
-  @$pb.TagNumber(4)
-  void clearEk() => clearField(4);
-
-  @$pb.TagNumber(5)
-  OMEMOAuthenticatedMessage get message => $_getN(4);
-  @$pb.TagNumber(5)
-  set message(OMEMOAuthenticatedMessage v) { setField(5, v); }
-  @$pb.TagNumber(5)
-  $core.bool hasMessage() => $_has(4);
-  @$pb.TagNumber(5)
-  void clearMessage() => clearField(5);
-  @$pb.TagNumber(5)
-  OMEMOAuthenticatedMessage ensureMessage() => $_ensure(4);
-}
-

lib/protobuf/schema.pbenum.dart

@@ -1,7 +0,0 @@
-///
-//  Generated code. Do not modify.
-//  source: schema.proto
-//
-// @dart = 2.12
-// ignore_for_file: annotate_overrides,camel_case_types,constant_identifier_names,directives_ordering,library_prefixes,non_constant_identifier_names,prefer_final_fields,return_of_invalid_type,unnecessary_const,unnecessary_import,unnecessary_this,unused_import,unused_shown_name
-

lib/protobuf/schema.pbjson.dart

@@ -1,48 +0,0 @@
-///
-//  Generated code. Do not modify.
-//  source: schema.proto
-//
-// @dart = 2.12
-// ignore_for_file: annotate_overrides,camel_case_types,constant_identifier_names,deprecated_member_use_from_same_package,directives_ordering,library_prefixes,non_constant_identifier_names,prefer_final_fields,return_of_invalid_type,unnecessary_const,unnecessary_import,unnecessary_this,unused_import,unused_shown_name
-
-import 'dart:core' as $core;
-import 'dart:convert' as $convert;
-import 'dart:typed_data' as $typed_data;
-@$core.Deprecated('Use oMEMOMessageDescriptor instead')
-const OMEMOMessage$json = const {
-  '1': 'OMEMOMessage',
-  '2': const [
-    const {'1': 'n', '3': 1, '4': 2, '5': 13, '10': 'n'},
-    const {'1': 'pn', '3': 2, '4': 2, '5': 13, '10': 'pn'},
-    const {'1': 'dh_pub', '3': 3, '4': 2, '5': 12, '10': 'dhPub'},
-    const {'1': 'ciphertext', '3': 4, '4': 1, '5': 12, '10': 'ciphertext'},
-  ],
-};
-
-/// Descriptor for `OMEMOMessage`. Decode as a `google.protobuf.DescriptorProto`.
-final $typed_data.Uint8List oMEMOMessageDescriptor = $convert.base64Decode('CgxPTUVNT01lc3NhZ2USDAoBbhgBIAIoDVIBbhIOCgJwbhgCIAIoDVICcG4SFQoGZGhfcHViGAMgAigMUgVkaFB1YhIeCgpjaXBoZXJ0ZXh0GAQgASgMUgpjaXBoZXJ0ZXh0');
-@$core.Deprecated('Use oMEMOAuthenticatedMessageDescriptor instead')
-const OMEMOAuthenticatedMessage$json = const {
-  '1': 'OMEMOAuthenticatedMessage',
-  '2': const [
-    const {'1': 'mac', '3': 1, '4': 2, '5': 12, '10': 'mac'},
-    const {'1': 'message', '3': 2, '4': 2, '5': 12, '10': 'message'},
-  ],
-};
-
-/// Descriptor for `OMEMOAuthenticatedMessage`. Decode as a `google.protobuf.DescriptorProto`.
-final $typed_data.Uint8List oMEMOAuthenticatedMessageDescriptor = $convert.base64Decode('ChlPTUVNT0F1dGhlbnRpY2F0ZWRNZXNzYWdlEhAKA21hYxgBIAIoDFIDbWFjEhgKB21lc3NhZ2UYAiACKAxSB21lc3NhZ2U=');
-@$core.Deprecated('Use oMEMOKeyExchangeDescriptor instead')
-const OMEMOKeyExchange$json = const {
-  '1': 'OMEMOKeyExchange',
-  '2': const [
-    const {'1': 'pk_id', '3': 1, '4': 2, '5': 13, '10': 'pkId'},
-    const {'1': 'spk_id', '3': 2, '4': 2, '5': 13, '10': 'spkId'},
-    const {'1': 'ik', '3': 3, '4': 2, '5': 12, '10': 'ik'},
-    const {'1': 'ek', '3': 4, '4': 2, '5': 12, '10': 'ek'},
-    const {'1': 'message', '3': 5, '4': 2, '5': 11, '6': '.OMEMOAuthenticatedMessage', '10': 'message'},
-  ],
-};
-
-/// Descriptor for `OMEMOKeyExchange`. Decode as a `google.protobuf.DescriptorProto`.
-final $typed_data.Uint8List oMEMOKeyExchangeDescriptor = $convert.base64Decode('ChBPTUVNT0tleUV4Y2hhbmdlEhMKBXBrX2lkGAEgAigNUgRwa0lkEhUKBnNwa19pZBgCIAIoDVIFc3BrSWQSDgoCaWsYAyACKAxSAmlrEg4KAmVrGAQgAigMUgJlaxI0CgdtZXNzYWdlGAUgAigLMhouT01FTU9BdXRoZW50aWNhdGVkTWVzc2FnZVIHbWVzc2FnZQ==');

lib/protobuf/schema.pbserver.dart

@@ -1,9 +0,0 @@
-///
-//  Generated code. Do not modify.
-//  source: schema.proto
-//
-// @dart = 2.12
-// ignore_for_file: annotate_overrides,camel_case_types,constant_identifier_names,deprecated_member_use_from_same_package,directives_ordering,library_prefixes,non_constant_identifier_names,prefer_final_fields,return_of_invalid_type,unnecessary_const,unnecessary_import,unnecessary_this,unused_import,unused_shown_name
-
-export 'schema.pb.dart';
-

lib/src/double_ratchet/double_ratchet.dart

@@ -67,6 +67,7 @@ class OmemoDoubleRatchet {
     this.ik,
     this.sessionAd,
     this.mkSkipped, // MKSKIPPED
+    this.acknowledged,
   );
 
   factory OmemoDoubleRatchet.fromJson(Map<String, dynamic> data) {
@@ -83,6 +84,7 @@ class OmemoDoubleRatchet {
       'pn': 0,
       'ik_pub': 'base/64/encoded',
       'session_ad': 'base/64/encoded',
+      'acknowledged': true | false,
       'mkskipped': [
         {
           'key': 'base/64/encoded',
@@ -117,6 +119,7 @@ class OmemoDoubleRatchet {
       ),
       base64.decode(data['session_ad']! as String),
       mkSkipped,
+      data['acknowledged']! as bool,
     );
   }
   
@@ -148,6 +151,10 @@ class OmemoDoubleRatchet {
 
   final Map<SkippedKey, List<int>> mkSkipped;
 
+  /// Indicates whether we received an empty OMEMO message after building a session with
+  /// the device.
+  bool acknowledged;
+
   /// Create an OMEMO session using the Signed Pre Key [spk], the shared secret [sk] that
   /// was obtained using a X3DH and the associated data [ad] that was also obtained through
   /// a X3DH. [ik] refers to Bob's (the receiver's) IK public key.
@@ -169,6 +176,7 @@ class OmemoDoubleRatchet {
       ik,
       ad,
       {},
+      false,
     );
   }
 
@@ -189,6 +197,7 @@ class OmemoDoubleRatchet {
       ik,
       ad,
       {},
+      true,
     );
   }
 
@@ -214,6 +223,7 @@ class OmemoDoubleRatchet {
       'ik_pub': base64.encode(await ik.getBytes()),
       'session_ad': base64.encode(sessionAd),
       'mkskipped': mkSkippedSerialised,
+      'acknowledged': acknowledged,
     };
   }
   
@@ -293,7 +303,11 @@ class OmemoDoubleRatchet {
       return plaintext;
     }
 
-    if (header.dhPub != await dhr?.getBytes()) {
+    final dhPubMatches = listsEqual(
+      header.dhPub ?? <int>[],
+      await dhr?.getBytes() ?? <int>[],
+    );
+    if (!dhPubMatches) {
       await _skipMessageKeys(header.pn!);
       await _dhRatchet(header);
     }

lib/src/omemo/device.dart

@@ -163,6 +163,23 @@ class Device {
     );
   }
 
+  /// Returns a new device that is equal to this one with the exception that the new
+  /// device's id is a new number between 0 and 2**32 - 1.
+  @internal
+  Device withNewId() {
+    return Device(
+      jid,
+      generateRandom32BitNumber(),
+      ik,
+      spk,
+      spkId,
+      spkSignature,
+      oldSpk,
+      oldSpkId,
+      opks,
+    );
+  }
+  
   /// Converts this device into an OmemoBundle that could be used for publishing.
   Future<OmemoBundle> toBundle() async {
     final encodedOpks = <int, String>{};

lib/src/omemo/events.dart

@@ -12,6 +12,14 @@ class RatchetModifiedEvent extends OmemoEvent {
   final OmemoDoubleRatchet ratchet;
 }
 
+/// Triggered when a ratchet has been removed and should be removed from storage.
+class RatchetRemovedEvent extends OmemoEvent {
+
+  RatchetRemovedEvent(this.jid, this.deviceId);
+  final String jid;
+  final int deviceId;
+}
+
 /// Triggered when the device map has been modified
 class DeviceMapModifiedEvent extends OmemoEvent {
 

lib/src/omemo/ratchet_map_key.dart

@@ -1,6 +1,5 @@
 import 'package:meta/meta.dart';
 
-@internal
 @immutable
 class RatchetMapKey {
 

lib/src/omemo/sessionmanager.dart

@@ -7,13 +7,13 @@ import 'package:meta/meta.dart';
 import 'package:omemo_dart/src/crypto.dart';
 import 'package:omemo_dart/src/double_ratchet/double_ratchet.dart';
 import 'package:omemo_dart/src/errors.dart';
-import 'package:omemo_dart/src/events.dart';
 import 'package:omemo_dart/src/helpers.dart';
 import 'package:omemo_dart/src/keys.dart';
 import 'package:omemo_dart/src/omemo/bundle.dart';
 import 'package:omemo_dart/src/omemo/device.dart';
 import 'package:omemo_dart/src/omemo/encrypted_key.dart';
 import 'package:omemo_dart/src/omemo/encryption_result.dart';
+import 'package:omemo_dart/src/omemo/events.dart';
 import 'package:omemo_dart/src/omemo/fingerprint.dart';
 import 'package:omemo_dart/src/omemo/ratchet_map_key.dart';
 import 'package:omemo_dart/src/protobuf/omemo_authenticated_message.dart';
@@ -50,6 +50,17 @@ class OmemoSessionManager {
     );
   }
 
+  /// Deserialise the OmemoSessionManager from JSON data [data] that does not contain
+  /// the ratchet sessions.
+  factory OmemoSessionManager.fromJsonWithoutSessions(Map<String, dynamic> data, Map<RatchetMapKey, OmemoDoubleRatchet> ratchetMap, TrustManager trustManager) {
+    return OmemoSessionManager(
+      Device.fromJson(data['device']! as Map<String, dynamic>),
+      data['devices']! as Map<String, List<int>>,
+      ratchetMap,
+      trustManager,
+    );
+  }
+  
   /// Generate a new cryptographic identity.
   static Future<OmemoSessionManager> generateNewIdentity(String jid, TrustManager trustManager, { int opkAmount = 100 }) async {
     assert(opkAmount > 0, 'opkAmount must be bigger than 0.');
@@ -78,10 +89,12 @@ class OmemoSessionManager {
 
   /// The trust manager
   final TrustManager _trustManager;
+  TrustManager get trustManager => _trustManager;
   
   /// A stream that receives events regarding the session
   Stream<OmemoEvent> get eventStream => _eventStreamController.stream;
 
+  /// Returns our own device.
   Future<Device> getDevice() async {
     Device? dev;
     await _deviceLock.synchronized(() async {
@@ -91,27 +104,40 @@ class OmemoSessionManager {
     return dev!;
   }
 
+  /// Returns the id attribute of our own device. This is just a short-hand for
+  /// ```await (session.getDevice()).id```.
+  Future<int> getDeviceId() async {
+    return _deviceLock.synchronized(() => _device.id);
+  }
+
+  /// Returns the device as an OmemoBundle. This is just a short-hand for
+  /// ```await (await session.getDevice()).toBundle()```.
+  Future<OmemoBundle> getDeviceBundle() async {
+    return _deviceLock.synchronized(() async => _device.toBundle());
+  }
+  
   /// Add a session [ratchet] with the [deviceId] to the internal tracking state.
   Future<void> _addSession(String jid, int deviceId, OmemoDoubleRatchet ratchet) async {
     await _lock.synchronized(() async {
       // Add the bundle Id
       if (!_deviceMap.containsKey(jid)) {
         _deviceMap[jid] = [deviceId];
-      } else {
-        _deviceMap[jid]!.add(deviceId);
-      }
 
-      // Commit the device map
-      _eventStreamController.add(DeviceMapModifiedEvent(_deviceMap));
+        // Commit the device map
+        _eventStreamController.add(DeviceMapModifiedEvent(_deviceMap));
+      } else {
+        // Prevent having the same device multiple times in the list
+        if (!_deviceMap[jid]!.contains(deviceId)) {
+          _deviceMap[jid]!.add(deviceId);
+
+          // Commit the device map
+          _eventStreamController.add(DeviceMapModifiedEvent(_deviceMap));
+        }
+      }
 
       // Add the ratchet session
       final key = RatchetMapKey(jid, deviceId);
-      if (!_ratchetMap.containsKey(key)) {
-        _ratchetMap[key] = ratchet;
-      } else {
-        // TODO(PapaTutuWawa): What do we do now?
-        throw Exception();
-      }
+      _ratchetMap[key] = ratchet;
 
       // Commit the ratchet
       _eventStreamController.add(RatchetModifiedEvent(jid, deviceId, ratchet));
@@ -224,8 +250,11 @@ class OmemoSessionManager {
       // We assume that the user already checked if the session exists
       for (final jid in jids) {
         for (final deviceId in _deviceMap[jid]!) {
-          // Only encrypt to devices that are trusted
-          if (!(await _trustManager.isTrusted(jid, deviceId))) continue;
+          // Empty OMEMO messages are allowed to bypass trust
+          if (plaintext != null) {
+            // Only encrypt to devices that are trusted
+            if (!(await _trustManager.isTrusted(jid, deviceId))) continue;
+          }
 
           final ratchetKey = RatchetMapKey(jid, deviceId);
           final ratchet = _ratchetMap[ratchetKey]!;
@@ -383,11 +412,89 @@ class OmemoSessionManager {
     });
   }
 
-  @visibleForTesting
-  OmemoDoubleRatchet getRatchet(String jid, int deviceId) => _ratchetMap[RatchetMapKey(jid, deviceId)]!;
+  /// Returns the device map, i.e. the mapping of bare Jid to its device identifiers
+  /// we have built sessions with.
+  Future<Map<String, List<int>>> getDeviceMap() async {
+    Map<String, List<int>>? map;
+
+    await _lock.synchronized(() async {
+      map = _deviceMap;
+    });
+
+    return map!;
+  }
+
+  /// Removes the ratchet identified by [jid] and [deviceId] from the session manager.
+  /// Also triggers events for commiting the new device map to storage and removing
+  /// the old ratchet.
+  Future<void> removeRatchet(String jid, int deviceId) async {
+    await _lock.synchronized(() async {
+      // Remove the ratchet
+      _ratchetMap.remove(RatchetMapKey(jid, deviceId));
+      // Commit it
+      _eventStreamController.add(RatchetRemovedEvent(jid, deviceId));
+
+      // Remove the device from jid
+      _deviceMap[jid]!.remove(deviceId);
+      if (_deviceMap[jid]!.isEmpty) {
+        _deviceMap.remove(jid);
+      }
+      // Commit it
+      _eventStreamController.add(DeviceMapModifiedEvent(_deviceMap));
+    });
+  }
+
+  /// Returns the list of device identifiers belonging to [jid] that are yet unacked, i.e.
+  /// we have not yet received an empty OMEMO message from.
+  Future<List<int>> getUnacknowledgedRatchets(String jid) async {
+    final ret = List<int>.empty(growable: true);
+
+    await _lock.synchronized(() async {
+      final devices = _deviceMap[jid]!;
+      for (final device in devices) {
+        final ratchet = _ratchetMap[RatchetMapKey(jid, device)]!;
+        if (!ratchet.acknowledged) ret.add(device);
+      }
+    });
+
+    return ret;
+  }
+
+  /// Mark the ratchet for device [deviceId] from [jid] as acked.
+  Future<void> ratchetAcknowledged(String jid, int deviceId) async {
+    await _lock.synchronized(() async {
+      final ratchet = _ratchetMap[RatchetMapKey(jid, deviceId)]!
+        ..acknowledged = true;
+
+      // Commit it
+      _eventStreamController.add(RatchetModifiedEvent(jid, deviceId, ratchet));
+    });
+  }
+
+  /// Generates an entirely new device. May be useful when the user wants to reset their cryptographic
+  /// identity. Triggers an event to commit it to storage.
+  Future<void> regenerateDevice({ int opkAmount = 100 }) async {
+    await _deviceLock.synchronized(() async {
+      _device = await Device.generateNewDevice(_device.jid, opkAmount: opkAmount);
+
+      // Commit it
+      _eventStreamController.add(DeviceModifiedEvent(_device));
+    });
+  }
+
+  /// Make our device have a new identifier. Only useful before publishing it as a bundle
+  /// to make sure that our device has a id that is account unique.
+  Future<void> regenerateDeviceId() async {
+    await _deviceLock.synchronized(() async {
+      _device = _device.withNewId();
+
+      // Commit it
+      _eventStreamController.add(DeviceModifiedEvent(_device));
+    });
+  }
   
   @visibleForTesting
-  Map<String, List<int>> getDeviceMap() => _deviceMap;
+  OmemoDoubleRatchet getRatchet(String jid, int deviceId) => _ratchetMap[RatchetMapKey(jid, deviceId)]!;
 
   @visibleForTesting
   Map<RatchetMapKey, OmemoDoubleRatchet> getRatchetMap() => _ratchetMap;
@@ -410,7 +517,6 @@ class OmemoSessionManager {
         },
         ...
       ],
-      'trust': { ... }
     }
     */
 
@@ -426,8 +532,25 @@ class OmemoSessionManager {
       'devices': _deviceMap,
       'device': await (await getDevice()).toJson(),
       'sessions': sessions,
-      // TODO(PapaTutuWawa): Implement
-      'trust': <String, dynamic>{},
+    };
+  }
+
+  /// Serialise the entire session manager into a JSON object.
+  Future<Map<String, dynamic>> toJsonWithoutSessions() async {
+    /*
+    {
+      'devices': {
+        'alice@...': [1, 2, ...],
+        'bob@...': [1],
+        ...
+      },
+      'device': { ... },
+    }
+    */
+
+    return {
+      'devices': _deviceMap,
+      'device': await (await getDevice()).toJson(),
     };
   }
 }

lib/src/trust/btbv.dart

@@ -13,29 +13,33 @@ enum BTBVTrustState {
   verified,
 }
 
-class BlindTrustBeforeVerificationTrustManager extends TrustManager {
+/// A TrustManager that implements the idea of Blind Trust Before Verification.
+/// See https://gultsch.de/trust.html for more details.
+abstract class BlindTrustBeforeVerificationTrustManager extends TrustManager {
   BlindTrustBeforeVerificationTrustManager()
-    : _trustCache = {},
-      _devices = {},
+    : trustCache = {},
+      devices = {},
       _lock = Lock();
 
   /// The cache for Mapping a RatchetMapKey to its trust state
-  final Map<RatchetMapKey, BTBVTrustState> _trustCache;
+  @protected
+  final Map<RatchetMapKey, BTBVTrustState> trustCache;
 
   /// Mapping of Jids to their device identifiers
-  final Map<String, List<int>> _devices;
+  @protected
+  final Map<String, List<int>> devices;
 
-  /// The lock for _devices and _trustCache
+  /// The lock for devices and trustCache
   final Lock _lock;
 
   /// Returns true if [jid] has at least one device that is verified. If not, returns false.
-  /// Note that this function accesses _devices and _trustCache, which requires that the
+  /// Note that this function accesses devices and trustCache, which requires that the
   /// lock for those two maps (_lock) has been aquired before calling.
   bool _hasAtLeastOneVerifiedDevice(String jid) {
-    if (!_devices.containsKey(jid)) return false;
+    if (!devices.containsKey(jid)) return false;
 
-    return _devices[jid]!.any((id) {
-      return _trustCache[RatchetMapKey(jid, id)]! == BTBVTrustState.verified;
+    return devices[jid]!.any((id) {
+      return trustCache[RatchetMapKey(jid, id)]! == BTBVTrustState.verified;
     });
   }
   
@@ -43,7 +47,7 @@ class BlindTrustBeforeVerificationTrustManager extends TrustManager {
   Future<bool> isTrusted(String jid, int deviceId) async {
     var returnValue = false;
     await _lock.synchronized(() async {
-      final trustCacheValue = _trustCache[RatchetMapKey(jid, deviceId)];
+      final trustCacheValue = trustCache[RatchetMapKey(jid, deviceId)];
       if (trustCacheValue == BTBVTrustState.notTrusted) {
         returnValue = false;
         return;
@@ -71,16 +75,19 @@ class BlindTrustBeforeVerificationTrustManager extends TrustManager {
   Future<void> onNewSession(String jid, int deviceId) async {
     await _lock.synchronized(() async {
       if (_hasAtLeastOneVerifiedDevice(jid)) {
-        _trustCache[RatchetMapKey(jid, deviceId)] = BTBVTrustState.notTrusted;
+        trustCache[RatchetMapKey(jid, deviceId)] = BTBVTrustState.notTrusted;
       } else {
-        _trustCache[RatchetMapKey(jid, deviceId)] = BTBVTrustState.blindTrust;
+        trustCache[RatchetMapKey(jid, deviceId)] = BTBVTrustState.blindTrust;
       }
 
-      if (_devices.containsKey(jid)) {
-        _devices[jid]!.add(deviceId);
+      if (devices.containsKey(jid)) {
+        devices[jid]!.add(deviceId);
       } else {
-        _devices[jid] = List<int>.from([deviceId]);
+        devices[jid] = List<int>.from([deviceId]);
       }
+
+      // Commit the state
+      await commitState();
     });
   }
   
@@ -89,8 +96,8 @@ class BlindTrustBeforeVerificationTrustManager extends TrustManager {
     final map = <int, BTBVTrustState>{};
 
     await _lock.synchronized(() async {
-      for (final deviceId in _devices[jid]!) {
-        map[deviceId] = _trustCache[RatchetMapKey(jid, deviceId)]!;
+      for (final deviceId in devices[jid]!) {
+        map[deviceId] = trustCache[RatchetMapKey(jid, deviceId)]!;
       }
     });
 
@@ -100,10 +107,33 @@ class BlindTrustBeforeVerificationTrustManager extends TrustManager {
   /// Sets the trust of [jid]'s device with identifier [deviceId] to [state].
   Future<void> setDeviceTrust(String jid, int deviceId, BTBVTrustState state) async {
     await _lock.synchronized(() async {
-      _trustCache[RatchetMapKey(jid, deviceId)] = state;
+      trustCache[RatchetMapKey(jid, deviceId)] = state;
+
+      // Commit the state
+      await commitState();
     });
   }
 
+  /// Called when the state of the trust manager has been changed. Allows the user to
+  /// commit the trust state to persistent storage.
+  @visibleForOverriding
+  Future<void> commitState();
+
+  /// Called when the user wants to restore the state of the trust manager. The format
+  /// and actual storage mechanism is left to the user.
+  @visibleForOverriding
+  Future<void> loadState();
+  
   @visibleForTesting
-  BTBVTrustState getDeviceTrust(String jid, int deviceId) => _trustCache[RatchetMapKey(jid, deviceId)]!;
+  BTBVTrustState getDeviceTrust(String jid, int deviceId) => trustCache[RatchetMapKey(jid, deviceId)]!;
+}
+
+/// A BTBV TrustManager that does not commit its state to persistent storage. Well suited
+/// for testing.
+class MemoryBTBVTrustManager extends BlindTrustBeforeVerificationTrustManager {
+  @override
+  Future<void> commitState() async {}
+
+  @override
+  Future<void> loadState() async {}
 }

lib/src/trust/never.dart

@@ -0,0 +1,14 @@
+import 'package:meta/meta.dart';
+import 'package:omemo_dart/src/trust/base.dart';
+
+/// Only use for testing!
+/// An implementation of TrustManager that never trusts any device and thus
+/// has no internal state.
+@visibleForTesting
+class NeverTrustingTrustManager extends TrustManager {
+  @override
+  Future<bool> isTrusted(String jid, int deviceId) async => false;
+
+  @override
+  Future<void> onNewSession(String jid, int deviceId) async {}
+}

pubspec.yaml

@@ -1,6 +1,8 @@
 name: omemo_dart
 description: An XMPP library independent OMEMO library
-version: 0.1.0
+version: 0.2.0
+homepage: https://github.com/PapaTutuWawa/omemo_dart
+publish_to: https://git.polynom.me/api/packages/PapaTutuWawa/pub
 
 environment:
   sdk: '>=2.17.0 <3.0.0'
@@ -9,6 +11,7 @@ dependencies:
   collection: ^1.16.0
   cryptography: ^2.0.5
   hex: ^0.2.0
+  meta: ^1.8.0
   pinenacl: ^0.5.1
   synchronized: ^3.0.0+2
 

test/omemo_test.dart

@@ -1,12 +1,12 @@
 import 'package:omemo_dart/omemo_dart.dart';
 import 'package:omemo_dart/src/trust/always.dart';
+import 'package:omemo_dart/src/trust/never.dart';
 import 'package:test/test.dart';
 
 void main() {
   test('Test using OMEMO sessions with only one device per user', () async {
     const aliceJid = 'alice@server.example';
     const bobJid = 'bob@other.server.example';
-      
     // Alice and Bob generate their sessions
     var deviceModified = false;
     var ratchetModified = 0;
@@ -38,7 +38,7 @@ void main() {
       bobJid,
       messagePlaintext,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 1);
@@ -50,7 +50,7 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, bobMessage);
@@ -81,7 +81,7 @@ void main() {
     final aliceReceivedMessage = await aliceSession.decryptMessage(
       bobResponseMessage.ciphertext,
       bobJid,
-      (await bobSession.getDevice()).id,
+      await bobSession.getDeviceId(),
       bobResponseMessage.encryptedKeys,
     );
     expect(bobResponseText, aliceReceivedMessage);
@@ -115,8 +115,8 @@ void main() {
       bobJid,
       messagePlaintext,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
-        await (await bobSession2.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
+        await bobSession2.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 2);
@@ -130,7 +130,7 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, bobMessage);
@@ -149,7 +149,7 @@ void main() {
     final aliceReceivedMessage = await aliceSession.decryptMessage(
       bobResponseMessage.ciphertext,
       bobJid,
-      (await bobSession.getDevice()).id,
+      await bobSession.getDeviceId(),
       bobResponseMessage.encryptedKeys,
     );
     expect(bobResponseText, aliceReceivedMessage);
@@ -192,8 +192,8 @@ void main() {
       [bobJid, aliceJid],
       messagePlaintext,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
-        await (await aliceSession2.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
+        await aliceSession2.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 2);
@@ -205,7 +205,7 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession1.getDevice()).id,
+      await aliceSession1.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, bobMessage);
@@ -214,7 +214,7 @@ void main() {
     final aliceMessage2 = await aliceSession2.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession1.getDevice()).id,
+      await aliceSession1.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, aliceMessage2);
@@ -241,7 +241,7 @@ void main() {
       bobJid,
       null,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 1);
@@ -254,13 +254,13 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(bobMessage, null);
 
     // This call must not cause an exception
-    bobSession.getRatchet(aliceJid, (await aliceSession.getDevice()).id);
+    bobSession.getRatchet(aliceJid, await aliceSession.getDeviceId());
   });
 
   test('Test rotating the Signed Prekey', () async {
@@ -316,7 +316,7 @@ void main() {
       bobJid,
       messagePlaintext,
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     expect(aliceMessage.encryptedKeys.length, 1);
@@ -331,9 +331,287 @@ void main() {
     final bobMessage = await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
     expect(messagePlaintext, bobMessage);
   });
+
+  test('Test trust bypassing with empty OMEMO messages', () async {
+    const aliceJid = 'alice@server.example';
+    const bobJid = 'bob@other.server.example';
+      
+    // Alice and Bob generate their sessions
+    final aliceSession = await OmemoSessionManager.generateNewIdentity(
+      aliceJid,
+      NeverTrustingTrustManager(),
+      opkAmount: 1,
+    );
+    final bobSession = await OmemoSessionManager.generateNewIdentity(
+      bobJid,
+      NeverTrustingTrustManager(),
+      opkAmount: 1,
+    );
+
+    // Alice encrypts an empty message for Bob
+    final aliceMessage = await aliceSession.encryptToJid(
+      bobJid,
+      null,
+      newSessions: [
+        await bobSession.getDeviceBundle(),
+      ],
+    );
+
+    // Despite Alice not trusting Bob's device, we should have encrypted it for his
+    // untrusted device.
+    expect(aliceMessage.encryptedKeys.length, 1);
+  });
+
+  test('Test by sending multiple messages back and forth', () async {
+    const aliceJid = 'alice@server.example';
+    const bobJid = 'bob@other.server.example';
+    // Alice and Bob generate their sessions
+    final aliceSession = await OmemoSessionManager.generateNewIdentity(
+      aliceJid,
+      AlwaysTrustingTrustManager(),
+      opkAmount: 1,
+    );
+    final bobSession = await OmemoSessionManager.generateNewIdentity(
+      bobJid,
+      AlwaysTrustingTrustManager(),
+      opkAmount: 1,
+    );
+
+    // Alice encrypts a message for Bob
+    final aliceMessage = await aliceSession.encryptToJid(
+      bobJid,
+      'Hello Bob!',
+      newSessions: [
+        await bobSession.getDeviceBundle(),
+      ],
+    );
+
+    // Alice sends the message to Bob
+    // ...
+
+    await bobSession.decryptMessage(
+      aliceMessage.ciphertext,
+      aliceJid,
+      await aliceSession.getDeviceId(),
+      aliceMessage.encryptedKeys,
+    );
+
+    for (var i = 0; i < 100; i++) {
+      final messageText = 'Test Message #$i';
+      // Bob responds to Alice
+      final bobResponseMessage = await bobSession.encryptToJid(
+        aliceJid,
+        messageText,
+      );
+
+      // Bob sends the message to Alice
+      // ...
+
+      // Alice decrypts it
+      final aliceReceivedMessage = await aliceSession.decryptMessage(
+        bobResponseMessage.ciphertext,
+        bobJid,
+        await bobSession.getDeviceId(),
+        bobResponseMessage.encryptedKeys,
+      );
+      expect(messageText, aliceReceivedMessage);
+    }
+  });
+
+  group('Test removing a ratchet', () {
+    test('Test removing a ratchet when the user has multiple', () async {
+      const aliceJid = 'alice@server.local';
+      const bobJid = 'bob@some.server.local';
+      final aliceSession = await OmemoSessionManager.generateNewIdentity(
+        aliceJid,
+        AlwaysTrustingTrustManager(),
+        opkAmount: 1,
+      );
+      final bobSession1 = await OmemoSessionManager.generateNewIdentity(
+        bobJid,
+        AlwaysTrustingTrustManager(),
+        opkAmount: 1,
+      );
+      final bobSession2 = await OmemoSessionManager.generateNewIdentity(
+        bobJid,
+        AlwaysTrustingTrustManager(),
+        opkAmount: 1,
+      );
+
+      // Alice sends a message to those two Bobs
+      await aliceSession.encryptToJid(
+        bobJid,
+        'Hallo Welt',
+        newSessions: [
+          await bobSession1.getDeviceBundle(),
+          await bobSession2.getDeviceBundle(),
+        ],
+      );
+
+      // One of those two sessions is broken, so Alice removes the session2 ratchet
+      final id1 = await bobSession1.getDeviceId();
+      final id2 = await bobSession2.getDeviceId();
+      await aliceSession.removeRatchet(bobJid, id1);
+
+      final map = aliceSession.getRatchetMap();
+      expect(map.containsKey(RatchetMapKey(bobJid, id1)), false);
+      expect(map.containsKey(RatchetMapKey(bobJid, id2)), true);
+      final deviceMap = await aliceSession.getDeviceMap();
+      expect(deviceMap.containsKey(bobJid), true);
+      expect(deviceMap[bobJid], [id2]);
+    });
+
+    test('Test removing a ratchet when the user has only one', () async {
+      const aliceJid = 'alice@server.local';
+      const bobJid = 'bob@some.server.local';
+      final aliceSession = await OmemoSessionManager.generateNewIdentity(
+        aliceJid,
+        AlwaysTrustingTrustManager(),
+        opkAmount: 1,
+      );
+      final bobSession = await OmemoSessionManager.generateNewIdentity(
+        bobJid,
+        AlwaysTrustingTrustManager(),
+        opkAmount: 1,
+      );
+
+      // Alice sends a message to those two Bobs
+      await aliceSession.encryptToJid(
+        bobJid,
+        'Hallo Welt',
+        newSessions: [
+          await bobSession.getDeviceBundle(),
+        ],
+      );
+
+      // One of those two sessions is broken, so Alice removes the session2 ratchet
+      final id = await bobSession.getDeviceId();
+      await aliceSession.removeRatchet(bobJid, id);
+
+      final map = aliceSession.getRatchetMap();
+      expect(map.containsKey(RatchetMapKey(bobJid, id)), false);
+      final deviceMap = await aliceSession.getDeviceMap();
+      expect(deviceMap.containsKey(bobJid), false);
+    });
+  });
+
+  test('Test acknowledging a ratchet', () async {
+    const aliceJid = 'alice@server.example';
+    const bobJid = 'bob@other.server.example';
+    // Alice and Bob generate their sessions
+    final aliceSession = await OmemoSessionManager.generateNewIdentity(
+      aliceJid,
+      AlwaysTrustingTrustManager(),
+      opkAmount: 1,
+    );
+    final bobSession = await OmemoSessionManager.generateNewIdentity(
+      bobJid,
+      AlwaysTrustingTrustManager(),
+      opkAmount: 1,
+    );
+
+    // Alice sends Bob a message
+    await aliceSession.encryptToJid(
+      bobJid,
+      'Hallo Welt',
+      newSessions: [
+        await bobSession.getDeviceBundle(),
+      ],
+    );
+    expect(
+      await aliceSession.getUnacknowledgedRatchets(bobJid),
+      [
+        await bobSession.getDeviceId(),
+      ],
+    );
+
+    // Bob sends alice an empty message
+    // ...
+
+    // Alice decrypts it
+    // ...
+
+    // Alice marks the ratchet as acknowledged
+    await aliceSession.ratchetAcknowledged(bobJid, await bobSession.getDeviceId());
+    expect(
+      (await aliceSession.getUnacknowledgedRatchets(bobJid)).isEmpty,
+      true,
+    );
+  });
+
+  test('Test overwriting sessions', () async {
+    const aliceJid = 'alice@server.example';
+    const bobJid = 'bob@other.server.example';
+    // Alice and Bob generate their sessions
+    final aliceSession = await OmemoSessionManager.generateNewIdentity(
+      aliceJid,
+      AlwaysTrustingTrustManager(),
+      opkAmount: 1,
+    );
+    final bobSession = await OmemoSessionManager.generateNewIdentity(
+      bobJid,
+      AlwaysTrustingTrustManager(),
+      opkAmount: 2,
+    );
+
+    // Alice sends Bob a message
+    final msg1 = await aliceSession.encryptToJid(
+      bobJid,
+      'Hallo Welt',
+      newSessions: [
+        await bobSession.getDeviceBundle(),
+      ],
+    );
+    await bobSession.decryptMessage(
+      msg1.ciphertext,
+      aliceJid,
+      await aliceSession.getDeviceId(),
+      msg1.encryptedKeys,
+    );
+    final aliceRatchet1 = aliceSession.getRatchet(
+      bobJid,
+      await bobSession.getDeviceId(),
+    );
+    final bobRatchet1 = bobSession.getRatchet(
+      aliceJid,
+      await aliceSession.getDeviceId(),
+    );
+
+    // Alice is impatient and immediately sends another message before the original one
+    // can be acknowledged by Bob
+    final msg2 = await aliceSession.encryptToJid(
+      bobJid,
+      "Why don't you answer?",
+      newSessions: [
+        await bobSession.getDeviceBundle(),
+      ],
+    );
+    await bobSession.decryptMessage(
+      msg2.ciphertext,
+      aliceJid,
+      await aliceSession.getDeviceId(),
+      msg2.encryptedKeys,
+    );
+    final aliceRatchet2 = aliceSession.getRatchet(
+      bobJid,
+      await bobSession.getDeviceId(),
+    );
+    final bobRatchet2 = bobSession.getRatchet(
+      aliceJid,
+      await aliceSession.getDeviceId(),
+    );
+
+    // Both should only have one ratchet
+    expect(aliceSession.getRatchetMap().length, 1);
+    expect(bobSession.getRatchetMap().length, 1);
+    
+    // The ratchets should both be different
+    expect(await aliceRatchet1.equals(aliceRatchet2), false);
+    expect(await bobRatchet1.equals(bobRatchet2), false);
+  });
 }

test/serialisation_test.dart

@@ -49,16 +49,16 @@ void main() {
       bobJid,
       'Hello Bob!',
       newSessions: [
-        await (await bobSession.getDevice()).toBundle(),
+        await bobSession.getDeviceBundle(),
       ],
     );
     await bobSession.decryptMessage(
       aliceMessage.ciphertext,
       aliceJid,
-      (await aliceSession.getDevice()).id,
+      await aliceSession.getDeviceId(),
       aliceMessage.encryptedKeys,
     );
-    final aliceOld = aliceSession.getRatchet(bobJid, (await bobSession.getDevice()).id);
+    final aliceOld = aliceSession.getRatchet(bobJid, await bobSession.getDeviceId());
     final aliceSerialised = await aliceOld.toJson();
     final aliceNew = OmemoDoubleRatchet.fromJson(aliceSerialised);
 
@@ -79,8 +79,8 @@ void main() {
     );
     await oldSession.addSessionFromBundle(
       'bob@localhost',
-      (await bobSession.getDevice()).id,
-      await (await bobSession.getDevice()).toBundle(),
+      await bobSession.getDeviceId(),
+      await bobSession.getDeviceBundle(),
     );
 
     // Serialise and deserialise
@@ -93,7 +93,7 @@ void main() {
     final oldDevice = await oldSession.getDevice();
     final newDevice = await newSession.getDevice();
     expect(await oldDevice.equals(newDevice), true);
-    expect(oldSession.getDeviceMap(), newSession.getDeviceMap());
+    expect(await oldSession.getDeviceMap(), await newSession.getDeviceMap());
 
     expect(oldSession.getRatchetMap().length, newSession.getRatchetMap().length);
     for (final session in oldSession.getRatchetMap().entries) {

test/trust_test.dart

@@ -4,7 +4,7 @@ import 'package:test/test.dart';
 void main() {
   test('Test the Blind Trust Before Verification TrustManager', () async {
     // Caroline's BTBV manager
-    final btbv = BlindTrustBeforeVerificationTrustManager();
+    final btbv = MemoryBTBVTrustManager();
     // Example data
     const aliceJid = 'alice@some.server';
     const bobJid = 'bob@other.server';