Feat: rust event verifier using native assets

.gitignore

@@ -35,4 +35,5 @@ build/
 .flutter-plugins-dependencies
 /packages/ndk/coverage/*
 /packages/ndk/coverage.lcov
-pubspec_overrides.yaml
+pubspec_overrides.yaml
+/packages/ndk/rust/target/

packages/ndk/hook/build.dart

@@ -0,0 +1,10 @@
+import 'package:hooks/hooks.dart';
+import 'package:native_toolchain_rust/native_toolchain_rust.dart';
+
+void main(List<String> args) async {
+  await build(args, (input, output) async {
+    await RustBuilder(
+      assetName: 'src/rust_lib.dart',
+    ).run(input: input, output: output);
+  });
+}

packages/ndk/lib/data_layer/repositories/verifiers/rust_event_verifier.dart

@@ -0,0 +1,11 @@
+/// Rust-based event verifier with platform-specific implementations.
+///
+/// On native platforms (Android, iOS, Linux, macOS, Windows), this uses FFI
+/// to call Rust code for high-performance event verification.
+///
+/// On web platforms, this exports a stub that throws [UnsupportedError].
+/// Use [Bip340EventVerifier] instead for web platforms.
+library;
+
+export 'rust_event_verifier_stub.dart'
+    if (dart.library.ffi) 'rust_event_verifier_native.dart';

packages/ndk/lib/data_layer/repositories/verifiers/rust_event_verifier_native.dart

@@ -0,0 +1,80 @@
+import 'dart:ffi';
+
+import 'package:ffi/ffi.dart';
+
+import '../../../domain_layer/entities/nip_01_event.dart';
+import '../../../domain_layer/repositories/event_verifier.dart';
+import '../../../src/rust_lib.dart' as rust_lib;
+
+/// An implementation of [EventVerifier] that uses native Rust for event verification.
+///
+/// This class provides a bridge between Dart and Rust via FFI using native assets,
+/// allowing for efficient verification of Nostr events using Rust's performance capabilities.
+class RustEventVerifier implements EventVerifier {
+  /// Creates a new instance of [RustEventVerifier].
+  RustEventVerifier();
+
+  @override
+  Future<bool> verify(Nip01Event event) async {
+    // Convert strings to native pointers
+    final eventIdPtr = event.id.toNativeUtf8();
+    final pubKeyPtr = event.pubKey.toNativeUtf8();
+    final contentPtr = event.content.toNativeUtf8();
+    final signaturePtr = event.sig.toNativeUtf8();
+
+    // Prepare tags data
+    final tags = event.tags;
+    final tagsCount = tags.length;
+
+    // Calculate total number of strings across all tags
+    int totalStrings = 0;
+    for (final tag in tags) {
+      totalStrings += tag.length;
+    }
+
+    // Allocate arrays for tags
+    final tagsLengths = calloc<Uint32>(tagsCount == 0 ? 1 : tagsCount);
+    final tagsData =
+        calloc<Pointer<Utf8>>(totalStrings == 0 ? 1 : totalStrings);
+
+    try {
+      // Fill tag data
+      int stringIndex = 0;
+      for (int i = 0; i < tagsCount; i++) {
+        tagsLengths[i] = tags[i].length;
+        for (final element in tags[i]) {
+          tagsData[stringIndex] = element.toNativeUtf8();
+          stringIndex++;
+        }
+      }
+
+      // Call the native function
+      final result = rust_lib.verifyNostrEventNative(
+        eventIdPtr,
+        pubKeyPtr,
+        event.createdAt,
+        event.kind,
+        tagsData,
+        tagsLengths,
+        tagsCount,
+        contentPtr,
+        signaturePtr,
+      );
+
+      return result == 1;
+    } finally {
+      // Free all allocated memory
+      calloc.free(eventIdPtr);
+      calloc.free(pubKeyPtr);
+      calloc.free(contentPtr);
+      calloc.free(signaturePtr);
+
+      // Free tag string pointers
+      for (int i = 0; i < totalStrings; i++) {
+        calloc.free(tagsData[i]);
+      }
+      calloc.free(tagsData);
+      calloc.free(tagsLengths);
+    }
+  }
+}

packages/ndk/lib/data_layer/repositories/verifiers/rust_event_verifier_stub.dart

@@ -0,0 +1,22 @@
+import '../../../domain_layer/entities/nip_01_event.dart';
+import '../../../domain_layer/repositories/event_verifier.dart';
+
+/// Stub implementation of [RustEventVerifier] for platforms that don't support FFI (e.g., web).
+///
+/// This class throws [UnsupportedError] for all operations since Rust FFI
+/// is not available on web platforms.
+class RustEventVerifier implements EventVerifier {
+  /// Creates a new instance of [RustEventVerifier].
+  ///
+  /// Note: On web platforms, this verifier is not functional and will throw
+  /// [UnsupportedError] when [verify] is called.
+  RustEventVerifier();
+
+  @override
+  Future<bool> verify(Nip01Event event) async {
+    throw UnsupportedError(
+      'RustEventVerifier is not available on this platform. '
+      'Use Bip340EventVerifier instead for web platforms.',
+    );
+  }
+}

packages/ndk/lib/ndk.dart

@@ -47,6 +47,7 @@ export 'domain_layer/entities/account.dart';
 export 'domain_layer/repositories/event_verifier.dart';
 export 'domain_layer/repositories/event_signer.dart';
 export 'data_layer/repositories/verifiers/bip340_event_verifier.dart';
+export 'data_layer/repositories/verifiers/rust_event_verifier.dart';
 export 'data_layer/repositories/signers/bip340_event_signer.dart';
 
 /// cache

packages/ndk/lib/src/rust_lib.dart

@@ -0,0 +1,48 @@
+import 'dart:ffi';
+
+import 'package:ffi/ffi.dart';
+
+/// FFI bindings to the native Rust library.
+/// This file is referenced by the native assets build hook.
+
+/// Verifies a Nostr event signature.
+///
+/// Returns 1 if valid, 0 if invalid.
+@Native<
+    Int32 Function(
+      Pointer<Utf8>, // eventIdHex
+      Pointer<Utf8>, // pubKeyHex
+      Uint64, // createdAt
+      Uint32, // kind
+      Pointer<Pointer<Utf8>>, // tagsData
+      Pointer<Uint32>, // tagsLengths
+      Uint32, // tagsCount
+      Pointer<Utf8>, // content
+      Pointer<Utf8>, // signatureHex
+    )>(symbol: 'verify_nostr_event')
+external int verifyNostrEventNative(
+  Pointer<Utf8> eventIdHex,
+  Pointer<Utf8> pubKeyHex,
+  int createdAt,
+  int kind,
+  Pointer<Pointer<Utf8>> tagsData,
+  Pointer<Uint32> tagsLengths,
+  int tagsCount,
+  Pointer<Utf8> content,
+  Pointer<Utf8> signatureHex,
+);
+
+/// Verifies a Schnorr signature.
+///
+/// Returns 1 if valid, 0 if invalid.
+@Native<
+    Int32 Function(
+      Pointer<Utf8>, // pubKeyHex
+      Pointer<Utf8>, // eventIdHex
+      Pointer<Utf8>, // signatureHex
+    )>(symbol: 'verify_schnorr_signature')
+external int verifySchnorrSignatureNative(
+  Pointer<Utf8> pubKeyHex,
+  Pointer<Utf8> eventIdHex,
+  Pointer<Utf8> signatureHex,
+);

packages/ndk/pubspec.lock

@@ -129,6 +129,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.2.0"
+  cli_util:
+    dependency: transitive
+    description:
+      name: cli_util
+      sha256: ff6785f7e9e3c38ac98b2fb035701789de90154024a75b6cb926445e83197d1c
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.4.2"
+  code_assets:
+    dependency: transitive
+    description:
+      name: code_assets
+      sha256: "83ccdaa064c980b5596c35dd64a8d3ecc68620174ab9b90b6343b753aa721687"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.0"
   code_builder:
     dependency: transitive
     description:
@@ -202,13 +218,21 @@ packages:
     source: hosted
     version: "2.0.7"
   ffi:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: ffi
       sha256: "289279317b4b16eb2bb7e271abccd4bf84ec9bdcbe999e278a94b804f5630418"
       url: "https://pub.dev"
     source: hosted
     version: "2.1.4"
+  ffigen:
+    dependency: "direct dev"
+    description:
+      name: ffigen
+      sha256: b7803707faeec4ce3c1b0c2274906504b796e3b70ad573577e72333bd1c9b3ba
+      url: "https://pub.dev"
+    source: hosted
+    version: "20.1.1"
   file:
     dependency: transitive
     description:
@@ -257,6 +281,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.3.2"
+  hooks:
+    dependency: "direct main"
+    description:
+      name: hooks
+      sha256: "5d309c86e7ce34cd8e37aa71cb30cb652d3829b900ab145e4d9da564b31d59f7"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.0"
   http:
     dependency: "direct main"
     description:
@@ -361,6 +393,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "5.5.1"
+  native_toolchain_rust:
+    dependency: "direct main"
+    description:
+      name: native_toolchain_rust
+      sha256: b0e0a60c847db5ebc20939b78df5f17bcb63b2ff7fe75f437affeeab3dfed09d
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.1"
   node_preamble:
     dependency: transitive
     description:
@@ -385,6 +425,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.9.1"
+  petitparser:
+    dependency: transitive
+    description:
+      name: petitparser
+      sha256: "1a97266a94f7350d30ae522c0af07890c70b8e62c71e8e3920d1db4d23c057d1"
+      url: "https://pub.dev"
+    source: hosted
+    version: "7.0.1"
   pointycastle:
     dependency: "direct main"
     description:
@@ -417,6 +465,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.5.0"
+  quiver:
+    dependency: transitive
+    description:
+      name: quiver
+      sha256: ea0b925899e64ecdfbf9c7becb60d5b50e706ade44a85b2363be2a22d88117d2
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.2"
   rxdart:
     dependency: "direct main"
     description:
@@ -561,6 +617,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.6.12"
+  toml:
+    dependency: transitive
+    description:
+      name: toml
+      sha256: "35cd2a1351c14bd213f130f8efcbd3e0c18181bff0c8ca7a08f6822a2bede786"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.17.0"
   typed_data:
     dependency: transitive
     description:
@@ -641,5 +705,13 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.1.3"
+  yaml_edit:
+    dependency: transitive
+    description:
+      name: yaml_edit
+      sha256: ec709065bb2c911b336853b67f3732dd13e0336bd065cc2f1061d7610ddf45e3
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.3"
 sdks:
   dart: ">=3.9.0 <4.0.0"

packages/ndk/pubspec.yaml

@@ -34,6 +34,10 @@ dependencies:
   cryptography: ^2.7.0
   meta: ">=1.10.0 <2.0.0"
   xxh3: ^1.2.0
+  hooks: ^1.0.0
+  native_toolchain_rust: ^1.0.1
+  ffi: ^2.1.4
+
 
 dev_dependencies:
   build_runner: ^2.10.0
@@ -44,3 +48,4 @@ dev_dependencies:
   # shelf used for blossom mock server
   shelf: ^1.4.2
   shelf_router: ^1.1.4
+  ffigen: ^20.1.1