Create Event Signature

Author: hendrikebbers

abi-parser/pom.xml

@@ -24,8 +24,13 @@
       <scope>compile</scope>
     </dependency>
     <dependency>
-      <groupId>com.github.aelstad</groupId>
-      <artifactId>keccakj</artifactId>
+      <groupId>org.bouncycastle</groupId>
+      <artifactId>bcprov-jdk15to18</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <scope>test</scope>
     </dependency>
   </dependencies>
 

abi-parser/src/main/java/com/openelements/hiero/smartcontract/abi/model/AbiEvent.java

@@ -1,10 +1,10 @@
 package com.openelements.hiero.smartcontract.abi.model;
 
 import com.openelements.hiero.smartcontract.abi.util.HexConverter;
-import com.openelements.hiero.smartcontract.abi.util.KeccakSupport;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Objects;
+import org.bouncycastle.jcajce.provider.digest.Keccak;
 import org.jspecify.annotations.NonNull;
 
 public record AbiEvent(@NonNull String name, @NonNull List<AbiParameter> inputs, boolean anonymous) implements AbiEntry{
@@ -21,22 +21,21 @@ public AbiEntryType type() {
 
     @NonNull
     public String createEventSignature() {
-        if(!anonymous) {
-            throw new IllegalStateException("Cannot create anonymous topic for named event");
-        }
         final List<String> canonicalParameterTypes = inputs.stream().map(AbiParameter::getCanonicalType).toList();
         return name + "(" + String.join(",", canonicalParameterTypes) + ")";
     }
 
     @NonNull
     public byte[] createEventSignatureHash() {
         final String eventSignature = createEventSignature();
-        return KeccakSupport.keccak256(eventSignature.getBytes(StandardCharsets.UTF_8));
+        Keccak.DigestKeccak kecc = new Keccak.Digest256();
+        kecc.update(eventSignature.getBytes(StandardCharsets.UTF_8));
+        return kecc.digest();
     }
 
     @NonNull
     public String createEventSignatureHashAsHex() {
         final byte[] eventSignatureHash = createEventSignatureHash();
-        return HexConverter.bytesToHex(eventSignatureHash);
+        return "0x" + HexConverter.bytesToHex(eventSignatureHash);
     }
 }

abi-parser/src/main/java/com/openelements/hiero/smartcontract/abi/model/AbiParameterType.java

@@ -6,6 +6,7 @@ public enum AbiParameterType {
     BYTE32,
     BOOL,
     UINT256,
+    UINT,
     TUPLE;
 
     public static AbiParameterType of(final String name) {
@@ -15,6 +16,7 @@ public static AbiParameterType of(final String name) {
             case "bytes32" -> BYTE32;
             case "bool" -> BOOL;
             case "uint256" -> UINT256;
+            case "uint" -> UINT;
             default -> throw new IllegalArgumentException("Unknown value type: " + name);
         };
     }
@@ -27,6 +29,7 @@ public String getCanonicalType() {
             case BOOL -> "bool";
             case UINT256 -> "uint256";
             case TUPLE -> "tuple";
+            case UINT -> "uint256";
         };
     }
 

abi-parser/src/main/java/com/openelements/hiero/smartcontract/abi/util/HexConverter.java

@@ -18,6 +18,6 @@ public static String bytesToHex(@NonNull final byte[] bytes) {
             hexChars[j * 2] = HEX_ARRAY[v >>> 4];
             hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];
         }
-        return new String(hexChars, StandardCharsets.UTF_8);
+        return new String(hexChars, StandardCharsets.UTF_8).toLowerCase();
     }
 }

abi-parser/src/main/java/com/openelements/hiero/smartcontract/abi/util/KeccakSupport.java

@@ -3,5 +3,5 @@
     exports com.openelements.hiero.smartcontract.abi.model;
     exports com.openelements.hiero.smartcontract.abi.util;
     requires org.jspecify;
-    requires keccakj;
+    requires org.bouncycastle.provider;
 }

abi-parser/src/main/java/module-info.java

@@ -0,0 +1,52 @@
+package com.openelements.hiero.smartcontract.abi.test;
+
+import com.openelements.hiero.smartcontract.abi.model.AbiEvent;
+import com.openelements.hiero.smartcontract.abi.model.AbiParameter;
+import com.openelements.hiero.smartcontract.abi.model.AbiParameterType;
+import com.openelements.hiero.smartcontract.abi.util.HexConverter;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
+import java.util.List;
+import org.bouncycastle.jcajce.provider.digest.Keccak;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class AbiEventTests {
+
+    @Test
+    void testEventSignatureCreation() {
+        // Given
+        final List<AbiParameter> inputs = List.of(
+                new AbiParameter("identifier_", AbiParameterType.STRING, List.of(), false)
+        );
+        final AbiEvent event = new AbiEvent("HashAdded", inputs, false);
+
+
+        // When
+        String signature = event.createEventSignature();
+        String hashAsHex = event.createEventSignatureHashAsHex();
+
+        // Then
+        Assertions.assertEquals("HashAdded(string)", signature);
+        Assertions.assertEquals("0xe0c9f5e6f5abddac86dac0e02afc9f3fda7b7fc6d9454a13c51fcb28621e1e5f", hashAsHex);
+    }
+
+    @Test
+    void testEventSignatureCreation2() {
+        // Given
+        final List<AbiParameter> inputs = List.of(
+                new AbiParameter("count", AbiParameterType.UINT, List.of(), false)
+        );
+        final AbiEvent event = new AbiEvent("MissingVerificationCountUpdated", inputs, false);
+
+
+        // When
+        String signature = event.createEventSignature();
+        String hashAsHex = event.createEventSignatureHashAsHex();
+
+        // Then
+        Assertions.assertEquals("MissingVerificationCountUpdated(uint256)", signature);
+        Assertions.assertEquals("0x271219bdbb9b91472a5df68ef7a9d3f8de02f3c27b93a35306f888acf081ea60", hashAsHex);
+    }
+
+}

abi-parser/src/test/java/com/openelements/hiero/smartcontract/abi/test/AbiEventTests.java

@@ -0,0 +1,5 @@
+open module com.openelements.hiero.smartcontract.abi.test {
+    requires com.openelements.hiero.smartcontract.abi;
+    requires org.junit.jupiter.api;
+    requires org.bouncycastle.provider;
+}

abi-parser/src/test/java/module-info.java

@@ -66,6 +66,7 @@
     <jreleaser-maven-plugin.version>1.9.0</jreleaser-maven-plugin.version>
     <versions-maven-plugin.version>2.17.1</versions-maven-plugin.version>
     <keccakj.version>1.1.0</keccakj.version>
+    <bouncycastle.version>1.76</bouncycastle.version>
   </properties>
 
   <dependencyManagement>
@@ -197,6 +198,11 @@
         <artifactId>keccakj</artifactId>
         <version>${keccakj.version}</version>
       </dependency>
+      <dependency>
+        <groupId>org.bouncycastle</groupId>
+        <artifactId>bcprov-jdk15to18</artifactId>
+        <version>${bouncycastle.version}</version>
+      </dependency>
     </dependencies>
   </dependencyManagement>