V4.0.1

Fix schnorr vrf verification.

Author: mrtnetwork

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 4.0.1
+  
+  - Fix schnorr vrf verification.
+
 ## 4.0.0
 
 - Minimum required Dart SDK version updated to 3.3.

lib/crypto/crypto/schnorrkel/keys/keys.dart

@@ -606,10 +606,7 @@ class SchnorrkelSecretKey {
       {GenerateRandom? nonceGenerator,
       bool kusamaVRF = true,
       MerlinTranscript? verifyScript}) {
-    final publicHashPoint = publicKey().vrfHash(script);
-    final keyBig = BigintUtils.fromBytes(key(), byteOrder: Endian.little);
-    final mul = publicHashPoint * keyBig;
-    final vrf = VRFInOut._(publicHashPoint.toBytes(), mul.toBytes());
+    final vrf = vrfInOut(script);
     return Tuple(
         vrf,
         dleqProve(vrf,
@@ -618,6 +615,19 @@ class SchnorrkelSecretKey {
             verifyScript: verifyScript));
   }
 
+  /// This function computes the VRF (Verifiable Random Function) input and output
+  /// using the provided `MerlinTranscript` as the cryptographic context.
+  ///
+  /// The process involves hashing a transcript with the public key to generate
+  /// a curve point, multiplying this point with the private key, and returning
+  /// the corresponding VRF input and output.
+  VRFInOut vrfInOut(MerlinTranscript script) {
+    final publicHashPoint = publicKey().vrfHash(script);
+    final keyBig = BigintUtils.fromBytes(key(), byteOrder: Endian.little);
+    final mul = publicHashPoint * keyBig;
+    return VRFInOut._(publicHashPoint.toBytes(), mul.toBytes());
+  }
+
   /// Generates a Discrete Logarithm Equality Proof (DLEQ) for a Verifiable Random Function (VRF) output.
   ///
   /// This method generates a DLEQ proof for a given VRF output, ensuring the equality of discrete logarithms of

lib/layout/utils/utils.dart

@@ -16,23 +16,26 @@ class LayoutSerializationUtils {
     return const SubstrateScaleCUintEncoder().encode(value.toString());
   }
 
-  static Tuple<int, BigInt> decodeLength(List<int> bytes, {bool sign = false}) {
-    switch (bytes[0] & 0x03) {
+  static Tuple<int, BigInt> decodeLength(List<int> bytes,
+      {bool sign = false, int offset = 0}) {
+    final byte = bytes[offset];
+
+    switch (byte & 0x03) {
       case 0x00:
-        return Tuple(1, BigInt.from(bytes[0]) >> 2);
+        return Tuple(1, BigInt.from(byte) >> 2);
       case 0x01:
-        final val = BigintUtils.fromBytes(bytes.sublist(0, 2),
+        final val = BigintUtils.fromBytes(bytes.sublist(offset, offset + 2),
             sign: sign, byteOrder: Endian.little);
         return Tuple(2, val >> 2);
       case 0x02:
-        final val = BigintUtils.fromBytes(bytes.sublist(0, 4),
+        final val = BigintUtils.fromBytes(bytes.sublist(offset, offset + 4),
             sign: sign, byteOrder: Endian.little);
         return Tuple(4, val >> 2);
       default:
-        final int offset = (bytes[0] >> 2) + 5;
-        final val = BigintUtils.fromBytes(bytes.sublist(1, offset),
+        final int o = (byte >> 2) + 5;
+        final val = BigintUtils.fromBytes(bytes.sublist(offset + 1, offset + o),
             sign: sign, byteOrder: Endian.little);
-        return Tuple(offset, val);
+        return Tuple(o, val);
     }
   }
 

lib/signer/substrate/core/verifier.dart

@@ -25,13 +25,14 @@ abstract class BaseSubstrateVerifier {
     }
   }
   factory BaseSubstrateVerifier.fromSubstrate(Substrate substrate) {
+    final publicKey = substrate.publicKey.compressed;
     switch (substrate.coinConf.type) {
       case EllipticCurveTypes.ed25519:
-        return SubstrateED25519Verifier.fromKeyBytes(substrate.priveKey.raw);
+        return SubstrateED25519Verifier.fromKeyBytes(publicKey);
       case EllipticCurveTypes.secp256k1:
-        return SubstrateEcdsaVerifier.fromKeyBytes(substrate.priveKey.raw);
+        return SubstrateEcdsaVerifier.fromKeyBytes(publicKey);
       default:
-        return SubstrateSr25519Verifier.fromKeyBytes(substrate.priveKey.raw);
+        return SubstrateSr25519Verifier.fromKeyBytes(publicKey);
     }
   }
 }

lib/signer/substrate/signers/substrate_sr25519.dart

@@ -88,6 +88,32 @@ class SubstrateSr25519Signer implements BaseSubstrateSigner {
     }
     return vrfResult;
   }
+
+  bool vrfVerify(List<int> message, List<int> vrfSign,
+      {List<int>? context, List<int>? extra}) {
+    if (vrfSign.length != _SubstrateSr25519SignerConst.vrfResultLength &&
+        vrfSign.length != SchnorrkelKeyCost.vrfProofLength) {
+      throw ArgumentException(
+          "Invalid VrfSign bytes length. excepted: ${_SubstrateSr25519SignerConst.vrfResultLength}, ${SchnorrkelKeyCost.vrfProofLength} got: ${vrfSign.length} ");
+    }
+    final MerlinTranscript script =
+        _SubstrateSr25519SignerUtils.substrateVrfSignScript(message, context);
+    VRFPreOut output;
+    VRFProof proof;
+    if (vrfSign.length == SchnorrkelKeyCost.vrfProofLength) {
+      output = _signer.vrfInOut(script).toVRFPreOut();
+      proof = VRFProof.fromBytes(vrfSign);
+    } else {
+      output = VRFPreOut(vrfSign.sublist(0, SchnorrkelKeyCost.vrfPreOutLength));
+      proof = VRFProof.fromBytes(
+          vrfSign.sublist(SchnorrkelKeyCost.vrfPreOutLength));
+    }
+    return _signer.publicKey().vrfVerify(
+        _SubstrateSr25519SignerUtils.substrateVrfSignScript(message, context),
+        output,
+        proof,
+        verifyScript: _SubstrateSr25519SignerUtils.vrfScript(extra: extra));
+  }
 }
 
 /// Class representing an Substrate SR25519 Verifier for signature verification.

lib/utils/string/string.dart

@@ -62,6 +62,14 @@ class StringUtils {
     return value;
   }
 
+  /// add the '0x' prefix to a hexadecimal string if it exists.
+  static String add0x(String value) {
+    if (value.toLowerCase().startsWith("0x")) {
+      return value;
+    }
+    return "0x$value";
+  }
+
   /// Encodes the given [value] string into a list of bytes using the specified [type].
   ///
   /// The [type] parameter determines the encoding type to use, with UTF-8 being the default.

pubspec.yaml

@@ -1,6 +1,6 @@
 name: blockchain_utils
 description: Comprehensive Crypto & Blockchain Toolkit, Pure Dart, Cross-Platform, Encoding, Cryptography, Addresses, Mnemonics, & More.
-version: 4.0.0
+version: 4.0.1
 homepage: "https://github.com/mrtnetwork/blockchain_utils"
 repository: "https://github.com/mrtnetwork/blockchain_utils"
 Author: mrhaydari.t@gmail.com