feat: apply EIP-712 new implementation to Challenge class (#154)

Author: jbern0rd

release-please-config.json

@@ -1,5 +1,6 @@
 {
   "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
+  "always-update": true,
   "draft-pull-request": true,
   "include-component-in-tag": false,
   "include-v-in-tag": true,

src/main/java/com/iexec/commons/poco/eip712/entity/Challenge.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022-2023 IEXEC BLOCKCHAIN TECH
+ * Copyright 2022-2025 IEXEC BLOCKCHAIN TECH
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,18 +16,43 @@
 
 package com.iexec.commons.poco.eip712.entity;
 
-import lombok.AllArgsConstructor;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonPOJOBuilder;
+import com.iexec.commons.poco.eip712.EIP712TypedData;
+import com.iexec.commons.poco.eip712.EIP712Utils;
+import com.iexec.commons.poco.utils.HashUtils;
 import lombok.Builder;
-import lombok.Data;
-import lombok.NoArgsConstructor;
+import lombok.Value;
+import lombok.extern.slf4j.Slf4j;
+
+import java.util.stream.Stream;
 
 /**
  * Represents the Challenge type in an EIP-712 compliant challenge.
  */
-@Data
+@Slf4j
+@Value
 @Builder
-@AllArgsConstructor
-@NoArgsConstructor
-public class Challenge {
-    private String challenge;
+@JsonDeserialize(builder = Challenge.ChallengeBuilder.class)
+public class Challenge implements EIP712TypedData {
+    private static final String EIP712_TYPE = "Challenge(string challenge)";
+
+    String challenge;
+
+    public String computeMessageHash() {
+        final String[] encodedValues = Stream.of(EIP712_TYPE, challenge)
+                .map(EIP712Utils::encodeData)
+                .toArray(String[]::new);
+        if (log.isDebugEnabled()) {
+            log.debug("{}", EIP712_TYPE);
+            for (String value : encodedValues) {
+                log.debug("{}", value);
+            }
+        }
+        return HashUtils.concatenateAndHash(encodedValues);
+    }
+
+    @JsonPOJOBuilder(withPrefix = "")
+    public static class ChallengeBuilder {
+    }
 }

src/test/java/com/iexec/commons/poco/eip712/entity/ChallengeTests.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2025 IEXEC BLOCKCHAIN TECH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.iexec.commons.poco.eip712.entity;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.iexec.commons.poco.eip712.EIP712Domain;
+import com.iexec.commons.poco.utils.HashUtils;
+import org.apache.commons.lang3.RandomStringUtils;
+import org.junit.jupiter.api.Test;
+import org.web3j.crypto.Hash;
+import org.web3j.utils.Numeric;
+
+import java.math.BigInteger;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ChallengeTests {
+
+    private static final ObjectMapper mapper = new ObjectMapper();
+
+    @Test
+    void shouldSerializeAndDeserialize() throws JsonProcessingException {
+        final String payload = RandomStringUtils.randomAlphanumeric(20);
+        final Challenge challenge = Challenge.builder()
+                .challenge(payload)
+                .build();
+        String jsonString = mapper.writeValueAsString(challenge);
+        assertThat(jsonString).isEqualTo("{\"challenge\":\"" + payload + "\"}");
+        final Challenge parsedChallenge = mapper.readValue(jsonString, Challenge.class);
+        assertThat(parsedChallenge).usingRecursiveComparison().isEqualTo(challenge);
+        assertThat(challenge).hasToString("Challenge(challenge=" + payload + ")");
+    }
+
+    @Test
+    void shouldComputeHashForChallenge() {
+        final Challenge challenge = Challenge.builder()
+                .challenge("challenge")
+                .build();
+        final EIP712Domain domain = new EIP712Domain("COMMON", "1", 15L, null);
+        final String domainType = "EIP712Domain(string name,string version,uint256 chainId)";
+        final String domainSeparator = HashUtils.concatenateAndHash(
+                Numeric.toHexString(Hash.sha3(domainType.getBytes())),
+                Numeric.toHexString(Hash.sha3(domain.getName().getBytes())),
+                Numeric.toHexString(Hash.sha3(domain.getVersion().getBytes())),
+                Numeric.toHexString(Numeric.toBytesPadded(BigInteger.valueOf(domain.getChainId()), 32)));
+        final String messageType = "Challenge(string challenge)";
+        final String messageHash = HashUtils.concatenateAndHash(
+                Numeric.toHexString(Hash.sha3(messageType.getBytes())),
+                Numeric.toHexString(Hash.sha3("challenge".getBytes())));
+        assertThat(challenge.computeMessageHash()).isEqualTo(messageHash);
+        final String hash = HashUtils.concatenateAndHash(
+                "0x1901",
+                domainSeparator,
+                messageHash);
+        assertThat(challenge.computeHash(domain))
+                .isEqualTo(hash)
+                .isEqualTo("0xea5ec041da81859f2c04a4876d5999ed8e66ad221b5b8699ca91f6814693a80e");
+    }
+
+}