Add ECCompressedPublicKey class

coinlib/lib/src/coinlib_base.dart

@@ -4,6 +4,7 @@ export 'package:coinlib/src/common/bytes.dart';
 export 'package:coinlib/src/common/hex.dart';
 export 'package:coinlib/src/common/serial.dart';
 
+export 'package:coinlib/src/crypto/ec_compressed_public_key.dart';
 export 'package:coinlib/src/crypto/ec_private_key.dart';
 export 'package:coinlib/src/crypto/ec_public_key.dart';
 export 'package:coinlib/src/crypto/ecdsa_signature.dart';

coinlib/lib/src/crypto/ec_compressed_public_key.dart

@@ -0,0 +1,31 @@
+import 'dart:typed_data';
+
+import 'package:coinlib/src/common/hex.dart';
+import 'ec_public_key.dart';
+
+/// Represents an [ECPublicKey] that must be in a compressed format, or else a
+/// [InvalidPublicKey] will be thrown.
+class ECCompressedPublicKey extends ECPublicKey {
+
+ ECCompressedPublicKey(super.data) {
+ if (data.length != 33) throw InvalidPublicKey();
+ }
+ ECCompressedPublicKey.fromHex(String hex) : this(hexToBytes(hex));
+ ECCompressedPublicKey.fromXOnly(super.xcoord) : super.fromXOnly();
+ ECCompressedPublicKey.fromXOnlyHex(super.hex) : super.fromXOnlyHex();
+ ECCompressedPublicKey.fromPubkey(ECPublicKey key) : this(
+ key.compressed
+ ? key.data
+ : Uint8List.fromList([key.yIsEven ? 2 : 3, ...key.x]),
+ );
+
+ @override
+ ECCompressedPublicKey? tweak(Uint8List scalar) {
+ final tweaked = super.tweak(scalar);
+ return tweaked == null ? null : ECCompressedPublicKey.fromPubkey(tweaked);
+ }
+
+ @override
+ ECCompressedPublicKey get xonly => ECCompressedPublicKey.fromXOnly(x);
+
+}

coinlib/test/crypto/ec_compressed_public_key_test.dart

@@ -0,0 +1,65 @@
+import 'package:coinlib/coinlib.dart';
+import 'package:test/test.dart';
+import '../vectors/keys.dart';
+
+void main() {
+
+ group("ECCompressedPublicKey", () {
+
+ setUpAll(loadCoinlib);
+
+ test("requires 33 bytes", () {
+
+ for (final failing in [
+ // Too small
+ pubkeyVec.substring(0, 32*2),
+ // Too large
+ longPubkeyVec,
+ "${pubkeyVec}ff",
+ ]) {
+ expect(
+ () => ECCompressedPublicKey.fromHex(failing),
+ throwsA(isA<InvalidPublicKey>()),
+ );
+ }
+
+ });
+
+ test("accepts compressed types", () {
+ for (final vec in validPubKeys) {
+ if (!vec.compressed) continue;
+ final pk = ECCompressedPublicKey.fromHex(vec.hex);
+ expect(pk.hex, vec.hex);
+ expect(pk.compressed, true);
+ expect(pk.yIsEven, vec.evenY);
+ }
+ });
+
+ test(".fromXOnly", () => expect(
+ ECCompressedPublicKey.fromXOnlyHex(xOnlyPubkeyVec).hex,
+ "02$xOnlyPubkeyVec",
+ ),);
+
+ test(".fromPubkey", () {
+
+ void expectCompressedKey(String pubkey, String compressed) => expect(
+ ECCompressedPublicKey.fromPubkey(ECPublicKey.fromHex(pubkey)).hex,
+ compressed,
+ );
+
+ expectCompressedKey(longPubkeyVec, pubkeyVec);
+ expectCompressedKey(pubkeyVec, pubkeyVec);
+ expectCompressedKey(
+ "06ef164284e2c3abc32b310eb62904af0d49196c51087bdf4038998f8818787c882433ae83422904f48ad36dcf351ac9a37e6b00e57cf40b469b650ec850640efe",
+ "02ef164284e2c3abc32b310eb62904af0d49196c51087bdf4038998f8818787c88",
+ );
+ expectCompressedKey(
+ "07576168b540f6f80e4d2a325f8cbd420ceb170ff42cd07e96bffc5e6a4a4ea04b1208f618306fd629cd2972cea45aa81ae7b24a64bf2e86704d7a63d82fd97a8f",
+ "03576168b540f6f80e4d2a325f8cbd420ceb170ff42cd07e96bffc5e6a4a4ea04b",
+ );
+
+ });
+
+ });
+
+}

coinlib/test/crypto/ec_public_key_test.dart

@@ -14,11 +14,11 @@ void main() {
 
  for (final failing in [
  // Too small
- "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f",
- "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f",
+ pubkeyVec.substring(0, 32*2),
+ longPubkeyVec.substring(0, 32*2),
  // Too large
- "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f2021",
- "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f2021",
+ "${pubkeyVec}ff",
+ "${longPubkeyVec}ff",
  ]) {
  expect(
  () => ECPublicKey.fromHex(failing),
@@ -46,10 +46,8 @@ void main() {
  test(".fromXOnly", () {
 
  expect(
- ECPublicKey.fromXOnlyHex(
- "d69c3509bb99e412e68b0fe8544e72837dfa30746d8be2aa65975f29d22dc7b9",
- ).hex,
- "02d69c3509bb99e412e68b0fe8544e72837dfa30746d8be2aa65975f29d22dc7b9",
+ ECCompressedPublicKey.fromXOnlyHex(xOnlyPubkeyVec).hex,
+ "02$xOnlyPubkeyVec",
  );
 
  for (final invalid in [

coinlib/test/vectors/keys.dart

@@ -20,6 +20,7 @@ class KeyTestVector {
 final pubkeyVec = "0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798";
 final longPubkeyVec = "0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8";
 final pubkeyhashVec = "751e76e8199196d454941c45d1b3a323f1433bd6";
+final xOnlyPubkeyVec = "d69c3509bb99e412e68b0fe8544e72837dfa30746d8be2aa65975f29d22dc7b9";
 
 final keyPairVectors = [
  KeyTestVector(