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fix: Migrate to custom protobuf

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This commit is contained in:
PapaTutuWawa 2022-08-05 12:59:10 +02:00
parent 5c3cc424de
commit 9ed94c8f3a
6 changed files with 93 additions and 83 deletions
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24
lib/src/double_ratchet/double_ratchet.dart
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@ -1,12 +1,12 @@
import 'package:cryptography/cryptography.dart';
import 'package:meta/meta.dart';
import 'package:omemo_dart/protobuf/schema.pb.dart';
import 'package:omemo_dart/src/crypto.dart';
import 'package:omemo_dart/src/double_ratchet/crypto.dart';
import 'package:omemo_dart/src/double_ratchet/kdf.dart';
import 'package:omemo_dart/src/errors.dart';
import 'package:omemo_dart/src/helpers.dart';
import 'package:omemo_dart/src/keys.dart';
import 'package:omemo_dart/src/protobuf/omemo_message.dart';
/// Amount of messages we may skip per session
const maxSkip = 1000;
@ -14,7 +14,7 @@ const maxSkip = 1000;
class RatchetStep {
const RatchetStep(this.header, this.ciphertext);
final OMEMOMessage header;
final OmemoMessage header;
final List<int> ciphertext;
}
@ -111,10 +111,10 @@ class OmemoDoubleRatchet {
);
}
Future<List<int>?> _trySkippedMessageKeys(OMEMOMessage header, List<int> ciphertext) async {
Future<List<int>?> _trySkippedMessageKeys(OmemoMessage header, List<int> ciphertext) async {
final key = SkippedKey(
OmemoPublicKey.fromBytes(header.dhPub, KeyPairType.x25519),
header.n,
OmemoPublicKey.fromBytes(header.dhPub!, KeyPairType.x25519),
header.n!,
);
if (mkSkipped.containsKey(key)) {
final mk = mkSkipped[key]!;
@ -142,11 +142,11 @@ class OmemoDoubleRatchet {
}
}
Future<void> _dhRatchet(OMEMOMessage header) async {
pn = header.n;
Future<void> _dhRatchet(OmemoMessage header) async {
pn = header.n!;
ns = 0;
nr = 0;
dhr = OmemoPublicKey.fromBytes(header.dhPub, KeyPairType.x25519);
dhr = OmemoPublicKey.fromBytes(header.dhPub!, KeyPairType.x25519);
final newRk = await kdfRk(rk, await omemoDH(dhs, dhr!, 0));
rk = newRk;
@ -163,7 +163,7 @@ class OmemoDoubleRatchet {
final mk = await kdfCk(cks!, kdfCkNextMessageKey);
cks = newCks;
final header = OMEMOMessage()
final header = OmemoMessage()
..dhPub = await dhs.pk.getBytes()
..pn = pn
..n = ns;
@ -180,7 +180,7 @@ class OmemoDoubleRatchet {
/// Ratchet. Returns the decrypted (raw) plaintext.
///
/// Throws an SkippingTooManyMessagesException if too many messages were to be skipped.
Future<List<int>> ratchetDecrypt(OMEMOMessage header, List<int> ciphertext) async {
Future<List<int>> ratchetDecrypt(OmemoMessage header, List<int> ciphertext) async {
// Check if we skipped too many messages
final plaintext = await _trySkippedMessageKeys(header, ciphertext);
if (plaintext != null) {
@ -188,11 +188,11 @@ class OmemoDoubleRatchet {
}
if (header.dhPub != await dhr?.getBytes()) {
await _skipMessageKeys(header.pn);
await _skipMessageKeys(header.pn!);
await _dhRatchet(header);
}
await _skipMessageKeys(header.n);
await _skipMessageKeys(header.n!);
final newCkr = await kdfCk(ckr!, kdfCkNextChainKey);
final mk = await kdfCk(ckr!, kdfCkNextMessageKey);
ckr = newCkr;

23
lib/src/omemo/sessionmanager.dart
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@ -1,7 +1,6 @@
import 'dart:convert';
import 'package:collection/collection.dart';
import 'package:cryptography/cryptography.dart';
import 'package:omemo_dart/protobuf/schema.pb.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';
@ -9,6 +8,9 @@ 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/protobuf/omemo_authenticated_message.dart';
import 'package:omemo_dart/src/protobuf/omemo_key_exchange.dart';
import 'package:omemo_dart/src/protobuf/omemo_message.dart';
import 'package:omemo_dart/src/x3dh/x3dh.dart';
import 'package:synchronized/synchronized.dart';
@ -80,7 +82,7 @@ class OmemoSessionManager {
/// Create a ratchet session initiated by Alice to the user with Jid [jid] and the device
/// [deviceId] from the bundle [bundle].
Future<OMEMOKeyExchange> addSessionFromBundle(String jid, int deviceId, OmemoBundle bundle) async {
Future<OmemoKeyExchange> addSessionFromBundle(String jid, int deviceId, OmemoBundle bundle) async {
final kexResult = await x3dhFromBundle(
bundle,
device.ik,
@ -93,9 +95,8 @@ class OmemoSessionManager {
await addSession(jid, deviceId, ratchet);
return OMEMOKeyExchange()
return OmemoKeyExchange()
..pkId = kexResult.opkId
// TODO(PapaTutuWawa): Fix
..spkId = 0
..ik = await device.ik.pk.getBytes()
..ek = await kexResult.ek.pk.getBytes();
@ -104,15 +105,15 @@ class OmemoSessionManager {
/// Build a new session with the user at [jid] with the device [deviceId] using data
/// from the key exchange [kex].
// TODO(PapaTutuWawa): Replace the OPK
Future<void> addSessionFromKeyExchange(String jid, int deviceId, OMEMOKeyExchange kex) async {
Future<void> addSessionFromKeyExchange(String jid, int deviceId, OmemoKeyExchange kex) async {
final kexResult = await x3dhFromInitialMessage(
X3DHMessage(
OmemoPublicKey.fromBytes(kex.ik, KeyPairType.ed25519),
OmemoPublicKey.fromBytes(kex.ek, KeyPairType.x25519),
kex.pkId,
OmemoPublicKey.fromBytes(kex.ik!, KeyPairType.ed25519),
OmemoPublicKey.fromBytes(kex.ek!, KeyPairType.x25519),
kex.pkId!,
),
device.spk,
device.opks.values.elementAt(kex.pkId),
device.opks.values.elementAt(kex.pkId!),
device.ik,
);
final ratchet = await OmemoDoubleRatchet.acceptNewSession(
@ -174,8 +175,8 @@ class OmemoSessionManager {
}
final decodedRawKey = base64.decode(rawKey.value);
final authMessage = OMEMOAuthenticatedMessage.fromBuffer(decodedRawKey);
final message = OMEMOMessage.fromBuffer(authMessage.message);
final authMessage = OmemoAuthenticatedMessage.fromBuffer(decodedRawKey);
final message = OmemoMessage.fromBuffer(authMessage.message!);
final ratchet = _ratchetMap[senderDeviceId]!;
final keyAndHmac = await ratchet.ratchetDecrypt(message, decodedRawKey);

18
lib/src/protobuf/omemo_authenticated_message.dart
View File

@ -3,7 +3,7 @@ import 'package:omemo_dart/src/protobuf/protobuf.dart';
class OmemoAuthenticatedMessage {
const OmemoAuthenticatedMessage(this.mac, this.message);
OmemoAuthenticatedMessage();
factory OmemoAuthenticatedMessage.fromBuffer(List<int> data) {
var i = 0;
@ -20,18 +20,20 @@ class OmemoAuthenticatedMessage {
}
final message = data.sublist(i + 2, i + 2 + data[i + 1]);
return OmemoAuthenticatedMessage(mac, message);
return OmemoAuthenticatedMessage()
..mac = mac
..message = message;
}
final List<int> mac;
final List<int> message;
List<int>? mac;
List<int>? message;
List<int> writeToBuffer() {
return concat([
[fieldId(1, fieldTypeByteArray), mac.length],
mac,
[fieldId(2, fieldTypeByteArray), message.length],
message,
[fieldId(1, fieldTypeByteArray), mac!.length],
mac!,
[fieldId(2, fieldTypeByteArray), message!.length],
message!,
]);
}
}

33
lib/src/protobuf/omemo_key_exchange.dart
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@ -4,7 +4,7 @@ import 'package:omemo_dart/src/protobuf/protobuf.dart';
class OmemoKeyExchange {
const OmemoKeyExchange(this.pkId, this.spkId, this.ik, this.ek, this.message);
OmemoKeyExchange();
factory OmemoKeyExchange.fromBuffer(List<int> data) {
var i = 0;
@ -40,26 +40,31 @@ class OmemoKeyExchange {
}
final message = OmemoAuthenticatedMessage.fromBuffer(data.sublist(i + 2));
return OmemoKeyExchange(pkId, spkId, ik, ek, message);
return OmemoKeyExchange()
..pkId = pkId
..spkId = spkId
..ik = ik
..ek = ek
..message = message;
}
final int pkId;
final int spkId;
final List<int> ik;
final List<int> ek;
final OmemoAuthenticatedMessage message;
int? pkId;
int? spkId;
List<int>? ik;
List<int>? ek;
OmemoAuthenticatedMessage? message;
List<int> writeToBuffer() {
final msg = message.writeToBuffer();
final msg = message!.writeToBuffer();
return concat([
[fieldId(1, fieldTypeUint32)],
encodeVarint(pkId),
encodeVarint(pkId!),
[fieldId(2, fieldTypeUint32)],
encodeVarint(spkId),
[fieldId(3, fieldTypeByteArray), ik.length],
ik,
[fieldId(4, fieldTypeByteArray), ek.length],
ek,
encodeVarint(spkId!),
[fieldId(3, fieldTypeByteArray), ik!.length],
ik!,
[fieldId(4, fieldTypeByteArray), ek!.length],
ek!,
[fieldId(5, fieldTypeByteArray), msg.length],
msg,
]);

30
lib/src/protobuf/omemo_message.dart
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@ -3,7 +3,7 @@ import 'package:omemo_dart/src/protobuf/protobuf.dart';
class OmemoMessage {
const OmemoMessage(this.n, this.pn, this.dhPub, this.ciphertext);
OmemoMessage();
factory OmemoMessage.fromBuffer(List<int> data) {
var i = 0;
@ -41,28 +41,32 @@ class OmemoMessage {
ciphertext = data.sublist(i + 2, i + 2 + data[i + 1]);
}
return OmemoMessage(n, pn, dhPub, ciphertext);
return OmemoMessage()
..n = n
..pn = pn
..dhPub = dhPub
..ciphertext = ciphertext;
}
final int n;
final int pn;
final List<int> dhPub;
final List<int>? ciphertext;
int? n;
int? pn;
List<int>? dhPub;
List<int>? ciphertext;
List<int> writeToBuffer() {
final data = concat([
[8],
encodeVarint(n),
[16],
encodeVarint(pn),
[((3 << 3) | 2), dhPub.length],
dhPub,
[fieldId(1, fieldTypeUint32)],
encodeVarint(n!),
[fieldId(2, fieldTypeUint32)],
encodeVarint(pn!),
[fieldId(3, fieldTypeByteArray), dhPub!.length],
dhPub!,
]);
if (ciphertext != null) {
return concat([
data,
[((4 << 3) | 2), ciphertext!.length],
[fieldId(4, fieldTypeByteArray), ciphertext!.length],
ciphertext!,
]);
}

48
test/protobuf_test.dart
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@ -79,12 +79,11 @@ void main() {
expect(msg.ciphertext, null);
});
test('Encode a OMEMOMessage', () {
const m = OmemoMessage(
1,
5,
<int>[1, 2, 3],
<int>[4, 5, 6],
);
final m = OmemoMessage()
..n = 1
..pn = 5
..dhPub = <int>[1, 2, 3]
..ciphertext = <int>[4, 5, 6];
final serial = m.writeToBuffer();
final msg = OMEMOMessage.fromBuffer(serial);
@ -94,12 +93,10 @@ void main() {
expect(msg.ciphertext, <int>[4, 5, 6]);
});
test('Encode a OMEMOMessage without ciphertext', () {
const m = OmemoMessage(
1,
5,
<int>[1, 2, 3],
null,
);
final m = OmemoMessage()
..n = 1
..pn = 5
..dhPub = <int>[1, 2, 3];
final serial = m.writeToBuffer();
final msg = OMEMOMessage.fromBuffer(serial);
@ -112,7 +109,9 @@ void main() {
group('OMEMOAuthenticatedMessage', () {
test('Test encoding a message', () {
const msg = OmemoAuthenticatedMessage(<int>[1, 2, 3], <int>[4, 5, 6]);
final msg = OmemoAuthenticatedMessage()
..mac = <int>[1, 2, 3]
..message = <int>[4, 5, 6];
final decoded = OMEMOAuthenticatedMessage.fromBuffer(msg.writeToBuffer());
expect(decoded.mac, <int>[1, 2, 3]);
@ -132,16 +131,15 @@ void main() {
group('OMEMOKeyExchange', () {
test('Test encoding a message', () {
const message = OmemoKeyExchange(
698,
245,
<int>[1, 4, 6],
<int>[4, 6, 7, 80],
OmemoAuthenticatedMessage(
<int>[5, 6, 8, 0],
<int>[4, 5, 7, 3, 2],
),
);
final authMessage = OmemoAuthenticatedMessage()
..mac = <int>[5, 6, 8, 0]
..message = <int>[4, 5, 7, 3, 2];
final message = OmemoKeyExchange()
..pkId = 698
..spkId = 245
..ik = <int>[1, 4, 6]
..ek = <int>[4, 6, 7, 80]
..message = authMessage;
final kex = OMEMOKeyExchange.fromBuffer(message.writeToBuffer());
expect(kex.pkId, 698);
@ -169,8 +167,8 @@ void main() {
expect(decoded.ik, <int>[1, 4, 6]);
expect(decoded.ek, <int>[4 ,6 ,7 , 80]);
expect(decoded.message.mac, <int>[5, 6, 8, 0]);
expect(decoded.message.message, <int>[4, 5, 7, 3, 2]);
expect(decoded.message!.mac, <int>[5, 6, 8, 0]);
expect(decoded.message!.message, <int>[4, 5, 7, 3, 2]);
});
});
}