1.4.0 (#30)

* feat: Add NIP04 support (#25)

* add encrypted direct messages (NIP04) support, with
code from https://github.com/vishalxl/nostr_console.git

* formatting + ok

* clean up comments

* add couple testcases

* remove couple dependencies

kepler: removed by adding Kepler class locally since the
github repo is archived
crypto: replace sha 256 hash with pointycastle equivalent

* re-org

* more re-org

* remove `encrypt` dependency

* message changes belong in separate PR

* comment fix

* leave comment on where kepler came from

* fix: #25 warnings

* refactor: PR #25

* fix: decipher bug, add Event.quick (#26)

* fix encrypt bug, add Event.quick

* a send and a receive unit test

* refactor: PR #26

* chore: rename/reorganize files from #25 & #26

* feat: NIPS 1, 5, 10, 19, 20, 28, 51

* refactor: nip20

* fix: useless import

* chore: format

* refactor: PR #29

* runtime data errors are exceptions not asserts

* refactor: PR #28

* chore: update documentation

* refactor: mark NIP04 as deprecated to warn users about controversial discussions about its harmfullness

* refactor: remove utility functions setMetadata, textNote and recommendServer

---------

Co-authored-by: no-prob <113266379+no-prob@users.noreply.github.com>
Co-authored-by: water <130329555+water783@users.noreply.github.com>
Co-authored-by: hazeycode <22148308+hazeycode@users.noreply.github.com>

.gitignore

@@ -1,6 +1,9 @@
 # Files and directories created by pub.
 .dart_tool/
 .packages
+*.swp
+x
+tags
 
 # Conventional directory for build outputs.
 build/

README.md

@@ -16,8 +16,15 @@ flutter pub add nostr
 ## [NIPS](https://github.com/nostr-protocol/nips)
 - [x] [NIP 01 Basic protocol flow description](https://github.com/nostr-protocol/nips/blob/master/01.md)
 - [x] [NIP 02 Contact List and Petnames](https://github.com/nostr-protocol/nips/blob/master/02.md)
+- [x] [NIP 04 Encrypted Direct Message](https://github.com/nostr-protocol/nips/blob/master/04.md)
+- [x] [NIP 05 Mapping Nostr keys to DNS-based internet identifiers](https://github.com/nostr-protocol/nips/blob/master/05.md)
+- [x] [NIP 10 Conventions for clients' use of e and p tags in text events](https://github.com/nostr-protocol/nips/blob/master/10.md)
 - [x] [NIP 15 End of Stored Events Notice](https://github.com/nostr-protocol/nips/blob/master/15.md)
+- [x] [NIP 19 bech32-encoded entities](https://github.com/nostr-protocol/nips/blob/master/19.md)
 - [x] [NIP 20 Command Results](https://github.com/nostr-protocol/nips/blob/master/20.md)
+- [x] [NIP 28 Public Chat](https://github.com/nostr-protocol/nips/blob/master/28.md)
+- [x] [NIP 51 Lists](https://github.com/nostr-protocol/nips/blob/master/51.md)
+
 
 ## Usage
 ### Events messages

example/message_example.dart

@@ -2,7 +2,7 @@ import 'package:nostr/nostr.dart';
 
 void main() async {
   var eventPayload =
-      '["EVENT","3979053091133091",{"id":"a60679692533b308f1d862c2a5ca5c08a304e5157b1df5cde0ff0454b9920605","pubkey":"7c579328cf9028a4548d5117afa4f8448fb510ca9023f576b7bc90fc5be6ce7e","created_at":1674405882,"kind":1,"tags":[],"content":"GM gm gm! Currently bathing my brain in coffee ☕️  hahaha. How many other nostrinos love coffee? 🤪🤙","sig":"10262aa6a83e0b744cda2097f06f7354357512b82846f6ef23ef7d997136b64815c343b613a0635a27da7e628c96ac2475f66dd72513c1fb8ce6560824eb25b8"}]';
+      '["EVENT","5ce1758166673a70e391303fb7cfeb0f5d47ec38a9342a27858950d13424d59b",{"content":"No quotes from the Bible? My global feed is full of religious nutcases","created_at":1685026912,"id":"e695c81fa5099b9f3ef0d868d8143eae481954114681bbe4432b50e44e199927","kind":1,"pubkey":"ab4103fc8cd4e1d8d31a99d079ed8293bdc26b11ec1ec61d95c13e43d7e048ff","sig":"0d17d6197ad12ab5ad77eb51231ae12c2ce1e639218bb6e3a01cce78aa092f3e77fb1f914b690675a425dcfd5b4dfa7be72c2cb608568798361781d75e354b32","tags":[["e","7804acd35bb9727d0374545a99bb4f30f901289aebaf3cf330dda28c235cd7ad"],["p","1bc70a0148b3f316da33fe3c89f23e3e71ac4ff998027ec712b905cd24f6a411"]]}]';
   var event = Message.deserialize(eventPayload);
   assert(event.type == "EVENT");
   assert(event.message.id ==

lib/nostr.dart

@@ -11,3 +11,10 @@ export 'src/close.dart';
 export 'src/message.dart';
 export 'src/utils.dart';
 export 'src/nips/nip_002.dart';
+export 'src/nips/nip_004.dart';
+export 'src/nips/nip_005.dart';
+export 'src/nips/nip_010.dart';
+export 'src/nips/nip_019.dart';
+export 'src/nips/nip_020.dart';
+export 'src/nips/nip_028.dart';
+export 'src/nips/nip_051.dart';

lib/src/close.dart

@@ -17,7 +17,7 @@ class Close {
   /// Deserialize a nostr close message
   /// - ["CLOSE", subscription_id]
   Close.deserialize(input) {
-    assert(input.length == 2);
+    if (input.length != 2) throw 'Invalid length for CLOSE message';
     subscriptionId = input[1];
   }
 }

lib/src/crypto/kepler.dart

@@ -0,0 +1,63 @@
+// credit: https://github.com/tjcampanella/kepler/blob/master/lib/src/kepler.dart
+
+import 'package:convert/convert.dart';
+import 'dart:typed_data';
+import 'package:pointycastle/export.dart';
+import 'operator.dart';
+
+class Kepler {
+  /// return a Bytes data secret
+  static List<List<int>> byteSecret(String privateString, String publicString) {
+    final secret = rawSecret(privateString, publicString);
+    assert(secret.x != null && secret.y != null);
+    final xs = secret.x!.toBigInteger()!.toRadixString(16);
+    final ys = secret.y!.toBigInteger()!.toRadixString(16);
+    final hexX = leftPadding(xs, 64);
+    final hexY = leftPadding(ys, 64);
+    final secretBytes = Uint8List.fromList(hex.decode('$hexX$hexY'));
+    return [secretBytes.sublist(0, 32), secretBytes.sublist(32, 40)];
+  }
+
+  /// return a ECPoint data secret
+  static ECPoint rawSecret(String privateString, String publicString) {
+    final privateKey = loadPrivateKey(privateString);
+    final publicKey = loadPublicKey(publicString);
+    assert(privateKey.d != null && publicKey.Q != null);
+    return scalarMultiple(privateKey.d!, publicKey.Q!);
+  }
+
+  static String leftPadding(String s, int width) {
+    const paddingData = '000000000000000';
+    final paddingWidth = width - s.length;
+    if (paddingWidth < 1) {
+      return s;
+    }
+    return "${paddingData.substring(0, paddingWidth)}$s";
+  }
+
+  /// return a privateKey from hex string
+  static ECPrivateKey loadPrivateKey(String storedkey) {
+    final d = BigInt.parse(storedkey, radix: 16);
+    final param = ECCurve_secp256k1();
+    return ECPrivateKey(d, param);
+  }
+
+  /// return a publicKey from hex string
+  static ECPublicKey loadPublicKey(String storedkey) {
+    final param = ECCurve_secp256k1();
+    if (storedkey.length < 120) {
+      List<int> codeList = [];
+      for (var idx = 0; idx < storedkey.length - 1; idx += 2) {
+        final hexStr = storedkey.substring(idx, idx + 2);
+        codeList.add(int.parse(hexStr, radix: 16));
+      }
+      final Q = param.curve.decodePoint(codeList);
+      return ECPublicKey(Q, param);
+    } else {
+      final x = BigInt.parse(storedkey.substring(0, 64), radix: 16);
+      final y = BigInt.parse(storedkey.substring(64), radix: 16);
+      final Q = param.curve.createPoint(x, y);
+      return ECPublicKey(Q, param);
+    }
+  }
+}

lib/src/crypto/nip_004.dart

@@ -0,0 +1,58 @@
+import 'dart:convert';
+import 'dart:typed_data';
+import 'package:nostr/nostr.dart';
+import 'package:nostr/src/crypto/kepler.dart';
+import 'package:pointycastle/export.dart';
+
+/// NIP4 cipher
+String nip4cipher(
+  String privkey,
+  String pubkey,
+  String payload,
+  bool cipher, {
+  String? nonce,
+}) {
+  // if cipher=false –> decipher –> nonce needed
+  if (!cipher && nonce == null) throw Exception("missing nonce");
+
+  // init variables
+  Uint8List input, output, iv;
+  if (!cipher && nonce != null) {
+    input = base64.decode(payload);
+    output = Uint8List(input.length);
+    iv = base64.decode(nonce);
+  } else {
+    input = Utf8Encoder().convert(payload);
+    output = Uint8List(input.length + 16);
+    iv = Uint8List.fromList(generateRandomBytes(16));
+  }
+
+  // params
+  List<List<int>> keplerSecret = Kepler.byteSecret(privkey, pubkey);
+  var key = Uint8List.fromList(keplerSecret[0]);
+  var params = PaddedBlockCipherParameters(
+    ParametersWithIV(KeyParameter(key), iv),
+    null,
+  );
+  var algo = PaddedBlockCipherImpl(
+    PKCS7Padding(),
+    CBCBlockCipher(AESEngine()),
+  );
+
+  // processing
+  algo.init(cipher, params);
+  var offset = 0;
+  while (offset < input.length - 16) {
+    offset += algo.processBlock(input, offset, output, offset);
+  }
+  offset += algo.doFinal(input, offset, output, offset);
+  Uint8List result = output.sublist(0, offset);
+
+  if (cipher) {
+    String stringIv = base64.encode(iv);
+    String plaintext = base64.encode(result);
+    return "$plaintext?iv=$stringIv";
+  } else {
+    return Utf8Decoder().convert(result);
+  }
+}

lib/src/crypto/operator.dart

@@ -0,0 +1,113 @@
+// credit: https://github.com/tjcampanella/kepler/blob/master/lib/src/operator.dart
+
+import 'package:pointycastle/export.dart';
+
+BigInt theP = BigInt.parse(
+    "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
+    radix: 16);
+BigInt theN = BigInt.parse(
+    "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141",
+    radix: 16);
+
+bool isOnCurve(ECPoint point) {
+  assert(point.x != null &&
+      point.y != null &&
+      point.curve.a != null &&
+      point.curve.b != null);
+  final x = point.x!.toBigInteger();
+  final y = point.y!.toBigInteger();
+  final rs = (y! * y -
+          x! * x * x -
+          point.curve.a!.toBigInteger()! * x -
+          point.curve.b!.toBigInteger()!) %
+      theP;
+  return rs == BigInt.from(0);
+}
+
+BigInt inverseMod(BigInt k, BigInt p) {
+  if (k.compareTo(BigInt.zero) == 0) {
+    throw Exception("Cannot Divide By 0");
+  }
+  if (k < BigInt.from(0)) {
+    return p - inverseMod(-k, p);
+  }
+  var s = [BigInt.from(0), BigInt.from(1), BigInt.from(1)];
+  var t = [BigInt.from(1), BigInt.from(0), BigInt.from(0)];
+  var r = [p, k, k];
+  while (r[0] != BigInt.from(0)) {
+    var quotient = r[2] ~/ r[0];
+    r[1] = r[2] - quotient * r[0];
+    r[2] = r[0];
+    r[0] = r[1];
+    s[1] = s[2] - quotient * s[0];
+    s[2] = s[0];
+    s[0] = s[1];
+    t[1] = t[2] - quotient * t[0];
+    t[2] = t[0];
+    t[0] = t[1];
+  }
+  final gcd = r[2];
+  final x = s[2];
+  // final y = t[2];
+  assert(gcd == BigInt.from(1));
+  assert((k * x) % p == BigInt.from(1));
+  return x % p;
+}
+
+ECPoint pointNeg(ECPoint point) {
+  assert(isOnCurve(point));
+  assert(point.x != null || point.y != null);
+  final x = point.x!.toBigInteger();
+  final y = point.y!.toBigInteger();
+  final result = point.curve.createPoint(x!, -y! % theP);
+  assert(isOnCurve(result));
+  return result;
+}
+
+ECPoint pointAdd(ECPoint? point1, ECPoint? point2) {
+  if (point1 == null) {
+    return point2!;
+  }
+  if (point2 == null) {
+    return point1;
+  }
+  assert(isOnCurve(point1));
+  assert(isOnCurve(point2));
+  final x1 = point1.x!.toBigInteger();
+  final y1 = point1.y!.toBigInteger();
+  final x2 = point2.x!.toBigInteger();
+  final y2 = point2.y!.toBigInteger();
+
+  BigInt m;
+  if (x1 == x2) {
+    m = (BigInt.from(3) * x1! * x1 + point1.curve.a!.toBigInteger()!) *
+        inverseMod(BigInt.from(2) * y1!, theP);
+  } else {
+    m = (y1! - y2!) * inverseMod(x1! - x2!, theP);
+  }
+  final x3 = m * m - x1 - x2!;
+  final y3 = y1 + m * (x3 - x1);
+  ECPoint result = point1.curve.createPoint(x3 % theP, -y3 % theP);
+  assert(isOnCurve(result));
+  return result;
+}
+
+ECPoint scalarMultiple(BigInt k, ECPoint point) {
+  assert(isOnCurve(point));
+  assert((k % theN).compareTo(BigInt.zero) != 0);
+  assert(point.x != null && point.y != null);
+  if (k < BigInt.from(0)) {
+    return scalarMultiple(-k, pointNeg(point));
+  }
+  ECPoint? result;
+  ECPoint addend = point;
+  while (k > BigInt.from(0)) {
+    if (k & BigInt.from(1) > BigInt.from(0)) {
+      result = pointAdd(result, addend);
+    }
+    addend = pointAdd(addend, addend);
+    k >>= 1;
+  }
+  assert(isOnCurve(result!));
+  return result!;
+}

lib/src/event.dart

@@ -1,6 +1,7 @@
 import 'dart:convert';
+import 'dart:typed_data';
 import 'package:convert/convert.dart';
-import 'package:crypto/crypto.dart';
+import 'package:pointycastle/export.dart';
 import 'package:bip340/bip340.dart' as bip340;
 import 'package:nostr/src/utils.dart';
 
@@ -85,7 +86,7 @@ class Event {
     bool verify = true,
   }) {
     pubkey = pubkey.toLowerCase();
-    if (verify) assert(isValid() == true);
+    if (verify && isValid() == false) throw 'Invalid event';
   }
 
   /// Partial constructor, you have to fill the fields yourself
@@ -127,27 +128,26 @@ class Event {
     );
   }
 
-  /// Instantiate Event object from the minimum available data
+  /// Instantiate Event object from the minimum needed data
   ///
   /// ```dart
   ///Event event = Event.from(
   ///  kind: 1,
-  ///  tags: [],
   ///  content: "",
   ///  privkey:
   ///      "5ee1c8000ab28edd64d74a7d951ac2dd559814887b1b9e1ac7c5f89e96125c12",
   ///);
   ///```
   factory Event.from({
-    int createdAt = 0,
+    int? createdAt,
     required int kind,
-    required List<List<String>> tags,
+    List<List<String>> tags = const [],
     required String content,
     required String privkey,
     String? subscriptionId,
     bool verify = false,
   }) {
-    if (createdAt == 0) createdAt = currentUnixTimestampSeconds();
+    createdAt ??= currentUnixTimestampSeconds();
     final pubkey = bip340.getPublicKey(privkey).toLowerCase();
 
     final id = _processEventId(
@@ -253,7 +253,7 @@ class Event {
       throw Exception('invalid input');
     }
 
-    var tags = (json['tags'] as List<dynamic>)
+    List<List<String>> tags = (json['tags'] as List<dynamic>)
         .map((e) => (e as List<dynamic>).map((e) => e as String).toList())
         .toList();
 
@@ -302,7 +302,8 @@ class Event {
   ) {
     List data = [0, pubkey.toLowerCase(), createdAt, kind, tags, content];
     String serializedEvent = json.encode(data);
-    List<int> hash = sha256.convert(utf8.encode(serializedEvent)).bytes;
+    Uint8List hash = SHA256Digest()
+        .process(Uint8List.fromList(utf8.encode(serializedEvent)));
     return hex.encode(hash);
   }
 

lib/src/message.dart

@@ -11,12 +11,19 @@ class Message {
   Message.deserialize(String payload) {
     dynamic data = jsonDecode(payload);
     var messages = ["EVENT", "REQ", "CLOSE", "NOTICE", "EOSE", "OK", "AUTH"];
-    assert(messages.contains(data[0]), "Unsupported payload (or NIP)");
+    if (messages.contains(data[0]) == false) {
+      throw 'Unsupported payload (or NIP)';
+    }
 
     type = data[0];
     switch (type) {
       case "EVENT":
         message = Event.deserialize(data);
+        // ignore: deprecated_member_use_from_same_package
+        if (message.kind == 4) message = EncryptedDirectMessage(message);
+        break;
+      case "OK":
+        message = Nip20.deserialize(data);
         break;
       case "REQ":
         message = Request.deserialize(data);