feat: Commit boost API - Generate Proxy Key

 -- Added routes and handler

core/src/main/java/tech/pegasys/web3signer/core/routes/eth2/CommitBoostGenerateProxyKeyRoute.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2024 ConsenSys AG.
+ *
+ * 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 tech.pegasys.web3signer.core.routes.eth2;
+
+import static tech.pegasys.web3signer.signing.KeyType.BLS;
+
+import tech.pegasys.web3signer.core.Context;
+import tech.pegasys.web3signer.core.routes.Web3SignerRoute;
+import tech.pegasys.web3signer.core.service.http.handlers.commitboost.CommitBoostGenerateProxyKeyHandler;
+import tech.pegasys.web3signer.core.service.http.handlers.signing.SignerForIdentifier;
+import tech.pegasys.web3signer.signing.ArtifactSignerProvider;
+import tech.pegasys.web3signer.signing.BlsArtifactSignature;
+import tech.pegasys.web3signer.signing.config.DefaultArtifactSignerProvider;
+
+import io.vertx.core.http.HttpMethod;
+import io.vertx.core.json.JsonObject;
+
+public class CommitBoostGenerateProxyKeyRoute implements Web3SignerRoute {
+  private static final String PATH = "/signer/v1/generate_proxy_key";
+  private final Context context;
+  private final SignerForIdentifier<BlsArtifactSignature> blsSigner;
+
+  public CommitBoostGenerateProxyKeyRoute(final Context context) {
+    this.context = context;
+
+    // there should be only one DefaultArtifactSignerProvider in eth2 mode
+    final ArtifactSignerProvider artifactSignerProvider =
+        context.getArtifactSignerProviders().stream()
+            .filter(p -> p instanceof DefaultArtifactSignerProvider)
+            .findFirst()
+            .orElseThrow();
+
+    blsSigner =
+        new SignerForIdentifier<>(
+            artifactSignerProvider, sig -> sig.getSignatureData().toString(), BLS);
+  }
+
+  @Override
+  public void register() {
+    context
+        .getRouter()
+        .route(HttpMethod.POST, PATH)
+        .blockingHandler(new CommitBoostGenerateProxyKeyHandler(blsSigner), false)
+        .failureHandler(context.getErrorHandler())
+        .failureHandler(
+            ctx -> {
+              final int statusCode = ctx.statusCode();
+              if (statusCode == 400) {
+                ctx.response()
+                    .setStatusCode(statusCode)
+                    .end(
+                        new JsonObject()
+                            .put("code", statusCode)
+                            .put("message", "Bad Request")
+                            .encode());
+              } else if (statusCode == 404) {
+                ctx.response()
+                    .setStatusCode(statusCode)
+                    .end(
+                        new JsonObject()
+                            .put("code", statusCode)
+                            .put("message", "Identifier not found.")
+                            .encode());
+              } else if (statusCode == 500) {
+                ctx.response()
+                    .setStatusCode(statusCode)
+                    .end(
+                        new JsonObject()
+                            .put("code", statusCode)
+                            .put("message", "Internal Server Error")
+                            .encode());
+              } else {
+                ctx.next(); // go to global failure handler
+              }
+            });
+  }
+}

core/src/main/java/tech/pegasys/web3signer/core/routes/eth2/CommitBoostPublicKeysRoute.java

@@ -44,7 +44,11 @@ public void register() {
               if (statusCode == 500) {
                 ctx.response()
                     .setStatusCode(statusCode)
-                    .end(new JsonObject().put("error", "Internal Server Error").encode());
+                    .end(
+                        new JsonObject()
+                            .put("code", statusCode)
+                            .put("message", "Internal Server Error")
+                            .encode());
               } else {
                 ctx.next(); // go to global failure handler
               }

core/src/main/java/tech/pegasys/web3signer/core/service/http/handlers/commitboost/CommitBoostGenerateProxyKeyHandler.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2024 ConsenSys AG.
+ *
+ * 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 tech.pegasys.web3signer.core.service.http.handlers.commitboost;
+
+import static io.vertx.core.http.HttpHeaders.CONTENT_TYPE;
+import static tech.pegasys.web3signer.core.service.http.handlers.ContentTypes.JSON_UTF_8;
+import static tech.pegasys.web3signer.signing.util.IdentifierUtils.normaliseIdentifier;
+
+import tech.pegasys.web3signer.core.service.http.SigningObjectMapperFactory;
+import tech.pegasys.web3signer.core.service.http.handlers.commitboost.json.GenerateProxyKeyBody;
+import tech.pegasys.web3signer.core.service.http.handlers.commitboost.json.GenerateProxyKeyResponse;
+import tech.pegasys.web3signer.core.service.http.handlers.commitboost.json.ProxyKeyMessage;
+import tech.pegasys.web3signer.core.service.http.handlers.signing.SignerForIdentifier;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.vertx.core.Handler;
+import io.vertx.ext.web.RoutingContext;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public class CommitBoostGenerateProxyKeyHandler implements Handler<RoutingContext> {
+  private static final Logger LOG = LogManager.getLogger();
+
+  private static final ObjectMapper JSON_MAPPER = SigningObjectMapperFactory.createObjectMapper();
+  public static final int NOT_FOUND = 404;
+  public static final int BAD_REQUEST = 400;
+  private static final int INTERNAL_ERROR = 500;
+  private final SignerForIdentifier<?> signerForIdentifier;
+
+  public CommitBoostGenerateProxyKeyHandler(final SignerForIdentifier<?> signerForIdentifier) {
+    this.signerForIdentifier = signerForIdentifier;
+  }
+
+  @Override
+  public void handle(final RoutingContext context) {
+    final String body = context.body().asString();
+
+    // read and validate incoming json body
+    final GenerateProxyKeyBody proxyKeyBody;
+    try {
+      proxyKeyBody = JSON_MAPPER.readValue(body, GenerateProxyKeyBody.class);
+    } catch (final JsonProcessingException | IllegalArgumentException e) {
+      context.fail(BAD_REQUEST);
+      return;
+    }
+
+    // Check for identifier, if not exist, fail with 404
+    final String identifier = normaliseIdentifier(proxyKeyBody.blsPublicKey());
+    if (!signerForIdentifier.isSignerAvailable(identifier)) {
+      context.fail(NOT_FOUND);
+      return;
+    }
+
+    // TODO: Generate actual proxy key based on signature scheme
+    // TODO: Add generated proxy key to DefaultArtifactSignerProvider
+
+    final ProxyKeyMessage proxyKeyMessage = new ProxyKeyMessage(identifier, "");
+
+    // TODO: Generate actual signature. This involves custom domain and zzs classes
+    final String signature = ""; // need tree-hash-root of ProxyKeyMessage
+
+    final GenerateProxyKeyResponse generateProxyKeyResponse =
+        new GenerateProxyKeyResponse(proxyKeyMessage, signature);
+
+    try {
+      final String jsonEncoded = JSON_MAPPER.writeValueAsString(generateProxyKeyResponse);
+      context.response().putHeader(CONTENT_TYPE, JSON_UTF_8).end(jsonEncoded);
+    } catch (final JsonProcessingException e) {
+      // this is not meant to happen
+      LOG.error("Failed to encode GenerateProxyKeyResponse to JSON", e);
+      context.fail(INTERNAL_ERROR);
+    }
+  }
+}

core/src/main/java/tech/pegasys/web3signer/core/service/http/handlers/commitboost/json/GenerateProxyKeyBody.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2024 ConsenSys AG.
+ *
+ * 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 tech.pegasys.web3signer.core.service.http.handlers.commitboost.json;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public record GenerateProxyKeyBody(
+    @JsonProperty(value = "pubkey", required = true) String blsPublicKey,
+    @JsonProperty(value = "scheme", required = true) String ProxyKeySignatureScheme) {}

core/src/main/java/tech/pegasys/web3signer/core/service/http/handlers/commitboost/json/GenerateProxyKeyResponse.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2024 ConsenSys AG.
+ *
+ * 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 tech.pegasys.web3signer.core.service.http.handlers.commitboost.json;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public record GenerateProxyKeyResponse(
+    @JsonProperty(value = "message") ProxyKeyMessage proxyKeyMessage,
+    @JsonProperty(value = "signature") String signature) {}

core/src/main/java/tech/pegasys/web3signer/core/service/http/handlers/commitboost/json/ProxyKeyMessage.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2024 ConsenSys AG.
+ *
+ * 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 tech.pegasys.web3signer.core.service.http.handlers.commitboost.json;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public record ProxyKeyMessage(
+    @JsonProperty(value = "delegator", required = true) String blsPublicKey,
+    @JsonProperty(value = "proxy", required = true) String proxyPublicKey) {}

core/src/main/java/tech/pegasys/web3signer/core/service/http/handlers/commitboost/json/ProxyKeySignatureScheme.java

@@ -0,0 +1,18 @@
+/*
+ * Copyright 2024 ConsenSys AG.
+ *
+ * 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 tech.pegasys.web3signer.core.service.http.handlers.commitboost.json;
+
+public enum ProxyKeySignatureScheme {
+  BLS,
+  ECDSA
+}