[NC-1742] Added host whitelist for Json-RPC. (#295)

acceptance-tests/src/test/java/tech/pegasys/pantheon/tests/acceptance/dsl/node/PantheonNodeFactory.java

@@ -13,6 +13,7 @@
 package tech.pegasys.pantheon.tests.acceptance.dsl.node;
 
 import static java.util.Arrays.asList;
+import static java.util.Collections.singletonList;
 import static java.util.stream.Collectors.toList;
 import static tech.pegasys.pantheon.consensus.clique.jsonrpc.CliqueRpcApis.CLIQUE;
 
@@ -154,6 +155,7 @@ public class PantheonNodeFactory {
     final JsonRpcConfiguration config = JsonRpcConfiguration.createDefault();
     config.setEnabled(true);
     config.setPort(0);
+    config.setHostsWhitelist(singletonList("*"));
     return config;
   }
 

ethereum/jsonrpc/src/main/java/tech/pegasys/pantheon/ethereum/jsonrpc/JsonRpcConfiguration.java

@@ -20,7 +20,7 @@ import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 
 public class JsonRpcConfiguration {
-  public static final String DEFAULT_JSON_RPC_HOST = "127.0.0.1";
+  private static final String DEFAULT_JSON_RPC_HOST = "127.0.0.1";
   public static final int DEFAULT_JSON_RPC_PORT = 8545;
 
   private boolean enabled;
@@ -28,6 +28,7 @@ public class JsonRpcConfiguration {
   private String host;
   private Collection<String> corsAllowedDomains = Collections.emptyList();
   private Collection<RpcApi> rpcApis;
+  private Collection<String> hostsWhitelist = Collections.singletonList("localhost");
 
   public static JsonRpcConfiguration createDefault() {
     final JsonRpcConfiguration config = new JsonRpcConfiguration();
@@ -87,6 +88,14 @@ public class JsonRpcConfiguration {
     rpcApis.add(rpcApi);
   }
 
+  public Collection<String> getHostsWhitelist() {
+    return Collections.unmodifiableCollection(this.hostsWhitelist);
+  }
+
+  public void setHostsWhitelist(final Collection<String> hostsWhitelist) {
+    this.hostsWhitelist = hostsWhitelist;
+  }
+
   @Override
   public String toString() {
     return MoreObjects.toStringHelper(this)
@@ -94,6 +103,7 @@ public class JsonRpcConfiguration {
         .add("port", port)
         .add("host", host)
         .add("corsAllowedDomains", corsAllowedDomains)
+        .add("hostsWhitelist", hostsWhitelist)
         .add("rpcApis", rpcApis)
         .toString();
   }
@@ -111,11 +121,12 @@ public class JsonRpcConfiguration {
         && port == that.port
         && Objects.equal(host, that.host)
         && Objects.equal(corsAllowedDomains, that.corsAllowedDomains)
+        && Objects.equal(hostsWhitelist, that.hostsWhitelist)
         && Objects.equal(rpcApis, that.rpcApis);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(enabled, port, host, corsAllowedDomains, rpcApis);
+    return Objects.hashCode(enabled, port, host, corsAllowedDomains, hostsWhitelist, rpcApis);
   }
 }

ethereum/jsonrpc/src/main/java/tech/pegasys/pantheon/ethereum/jsonrpc/JsonRpcHttpService.java

@@ -13,6 +13,7 @@
 package tech.pegasys.pantheon.ethereum.jsonrpc;
 
 import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.collect.Streams.stream;
 import static java.util.stream.Collectors.toList;
 import static tech.pegasys.pantheon.util.NetworkUtility.urlForSocketAddress;
 
@@ -38,13 +39,17 @@ import java.net.SocketException;
 import java.nio.file.Path;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.StringJoiner;
 import java.util.concurrent.CompletableFuture;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Splitter;
+import com.google.common.collect.Iterables;
 import io.netty.handler.codec.http.HttpResponseStatus;
 import io.vertx.core.CompositeFuture;
 import io.vertx.core.Future;
+import io.vertx.core.Handler;
 import io.vertx.core.Vertx;
 import io.vertx.core.http.HttpMethod;
 import io.vertx.core.http.HttpServer;
@@ -113,6 +118,10 @@ public class JsonRpcHttpService {
 
     // Handle json rpc requests
     final Router router = Router.router(vertx);
+
+    // Verify Host header to avoid rebind attack.
+    router.route().handler(checkWhitelistHostHeader());
+
     router
         .route()
         .handler(
@@ -161,6 +170,42 @@ public class JsonRpcHttpService {
     return resultFuture;
   }
 
+  private Handler<RoutingContext> checkWhitelistHostHeader() {
+    return event -> {
+      Optional<String> hostHeader = getAndValidateHostHeader(event);
+      if (config.getHostsWhitelist().contains("*")
+          || (hostHeader.isPresent() && hostIsInWhitelist(hostHeader))) {
+        event.next();
+      } else {
+        event
+            .response()
+            .setStatusCode(403)
+            .putHeader("Content-Type", "application/json; charset=utf-8")
+            .end("{\"message\":\"Host not authorized.\"}");
+      }
+    };
+  }
+
+  private Optional<String> getAndValidateHostHeader(final RoutingContext event) {
+    Iterable<String> splitHostHeader = Splitter.on(':').split(event.request().host());
+    long hostPieces = stream(splitHostHeader).count();
+    if (hostPieces > 1) {
+      // If the host contains a colon, verify the host is correctly formed - host [ ":" port ]
+      if (hostPieces > 2 || !Iterables.get(splitHostHeader, 1).matches("\\d{1,5}+")) {
+        return Optional.empty();
+      }
+    }
+    return Optional.ofNullable(Iterables.get(splitHostHeader, 0));
+  }
+
+  private boolean hostIsInWhitelist(final Optional<String> hostHeader) {
+    return config
+        .getHostsWhitelist()
+        .stream()
+        .anyMatch(
+            whitelistEntry -> whitelistEntry.toLowerCase().equals(hostHeader.get().toLowerCase()));
+  }
+
   public CompletableFuture<?> stop() {
     if (httpServer == null) {
       return CompletableFuture.completedFuture(null);

ethereum/jsonrpc/src/test/java/tech/pegasys/pantheon/ethereum/jsonrpc/JsonRpcHttpServiceHostWhitelistTest.java

@@ -0,0 +1,169 @@
+/*
+ * Copyright 2018 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.pantheon.ethereum.jsonrpc;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+
+import tech.pegasys.pantheon.config.StubGenesisConfigOptions;
+import tech.pegasys.pantheon.ethereum.blockcreation.EthHashMiningCoordinator;
+import tech.pegasys.pantheon.ethereum.core.Synchronizer;
+import tech.pegasys.pantheon.ethereum.core.TransactionPool;
+import tech.pegasys.pantheon.ethereum.eth.EthProtocol;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.filter.FilterManager;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.methods.JsonRpcMethod;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.queries.BlockchainQueries;
+import tech.pegasys.pantheon.ethereum.mainnet.MainnetProtocolSchedule;
+import tech.pegasys.pantheon.ethereum.p2p.api.P2PNetwork;
+import tech.pegasys.pantheon.ethereum.p2p.wire.Capability;
+import tech.pegasys.pantheon.metrics.noop.NoOpMetricsSystem;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import io.vertx.core.Vertx;
+import io.vertx.core.json.Json;
+import okhttp3.MediaType;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+public class JsonRpcHttpServiceHostWhitelistTest {
+
+  @ClassRule public static final TemporaryFolder folder = new TemporaryFolder();
+
+  protected static final Vertx vertx = Vertx.vertx();
+
+  private static Map<String, JsonRpcMethod> rpcMethods;
+  private static JsonRpcHttpService service;
+  private static OkHttpClient client;
+  private static String baseUrl;
+  private static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
+  private static final String CLIENT_VERSION = "TestClientVersion/0.1.0";
+  private static final int CHAIN_ID = 123;
+  private static final Collection<RpcApi> JSON_RPC_APIS =
+      Arrays.asList(RpcApis.ETH, RpcApis.NET, RpcApis.WEB3);
+  private final JsonRpcConfiguration jsonRpcConfig = createJsonRpcConfig();
+  private final List<String> hostsWhitelist = Arrays.asList("ally", "friend");
+
+  @Before
+  public void initServerAndClient() throws Exception {
+    P2PNetwork peerDiscoveryMock = mock(P2PNetwork.class);
+    BlockchainQueries blockchainQueries = mock(BlockchainQueries.class);
+    Synchronizer synchronizer = mock(Synchronizer.class);
+
+    final Set<Capability> supportedCapabilities = new HashSet<>();
+    supportedCapabilities.add(EthProtocol.ETH62);
+    supportedCapabilities.add(EthProtocol.ETH63);
+
+    rpcMethods =
+        spy(
+            new JsonRpcMethodsFactory()
+                .methods(
+                    CLIENT_VERSION,
+                    peerDiscoveryMock,
+                    blockchainQueries,
+                    synchronizer,
+                    MainnetProtocolSchedule.fromConfig(
+                        new StubGenesisConfigOptions().constantinopleBlock(0).chainId(CHAIN_ID)),
+                    mock(FilterManager.class),
+                    mock(TransactionPool.class),
+                    mock(EthHashMiningCoordinator.class),
+                    new NoOpMetricsSystem(),
+                    supportedCapabilities,
+                    JSON_RPC_APIS));
+    service = createJsonRpcHttpService();
+    service.start().join();
+
+    client = new OkHttpClient();
+    baseUrl = service.url();
+  }
+
+  private JsonRpcHttpService createJsonRpcHttpService() throws Exception {
+    return new JsonRpcHttpService(
+        vertx, folder.newFolder().toPath(), jsonRpcConfig, new NoOpMetricsSystem(), rpcMethods);
+  }
+
+  private static JsonRpcConfiguration createJsonRpcConfig() {
+    final JsonRpcConfiguration config = JsonRpcConfiguration.createDefault();
+    config.setPort(0);
+    return config;
+  }
+
+  @After
+  public void shutdownServer() {
+    service.stop().join();
+  }
+
+  @Test
+  public void requestWithDefaultHeaderAndDefaultConfigIsAccepted() throws IOException {
+    assertThat(doRequest("localhost:50012")).isEqualTo(200);
+  }
+
+  @Test
+  public void requestWithEmptyHeaderAndDefaultConfigIsRejected() throws IOException {
+    assertThat(doRequest("")).isEqualTo(403);
+  }
+
+  @Test
+  public void requestWithAnyHostnameAndWildcardConfigIsAccepted() throws IOException {
+    jsonRpcConfig.setHostsWhitelist(Collections.singletonList("*"));
+    assertThat(doRequest("ally")).isEqualTo(200);
+    assertThat(doRequest("foe")).isEqualTo(200);
+  }
+
+  @Test
+  public void requestWithWhitelistedHostIsAccepted() throws IOException {
+    jsonRpcConfig.setHostsWhitelist(hostsWhitelist);
+    assertThat(doRequest("ally")).isEqualTo(200);
+    assertThat(doRequest("ally:12345")).isEqualTo(200);
+    assertThat(doRequest("friend")).isEqualTo(200);
+  }
+
+  @Test
+  public void requestWithUnknownHostIsRejected() throws IOException {
+    jsonRpcConfig.setHostsWhitelist(hostsWhitelist);
+    assertThat(doRequest("foe")).isEqualTo(403);
+  }
+
+  private int doRequest(final String hostname) throws IOException {
+    final RequestBody body =
+        RequestBody.create(
+            JSON,
+            "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode("123") + ",\"method\":\"net_version\"}");
+
+    Request build =
+        new Request.Builder().post(body).url(baseUrl).addHeader("Host", hostname).build();
+    return client.newCall(build).execute().code();
+  }
+
+  @Test
+  public void requestWithMalformedHostIsRejected() throws IOException {
+    jsonRpcConfig.setHostsWhitelist(hostsWhitelist);
+    assertThat(doRequest("ally:friend")).isEqualTo(403);
+    assertThat(doRequest("ally:123456")).isEqualTo(403);
+    assertThat(doRequest("ally:friend:1234")).isEqualTo(403);
+  }
+}

ethereum/jsonrpc/src/test/java/tech/pegasys/pantheon/ethereum/jsonrpc/JsonRpcHttpServiceRpcApisTest.java

@@ -87,9 +87,8 @@ public class JsonRpcHttpServiceRpcApisTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"net_version\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
     }
   }
@@ -102,9 +101,8 @@ public class JsonRpcHttpServiceRpcApisTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"net_version\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
     }
   }
@@ -117,9 +115,8 @@ public class JsonRpcHttpServiceRpcApisTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"net_version\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -137,9 +134,8 @@ public class JsonRpcHttpServiceRpcApisTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"net_version\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
     }
   }
@@ -188,4 +184,8 @@ public class JsonRpcHttpServiceRpcApisTest {
     baseUrl = jsonRpcHttpService.url();
     return jsonRpcHttpService;
   }
+
+  private Request buildRequest(final RequestBody body) {
+    return new Request.Builder().post(body).url(baseUrl).build();
+  }
 }

ethereum/jsonrpc/src/test/java/tech/pegasys/pantheon/ethereum/jsonrpc/JsonRpcHttpServiceTest.java

@@ -131,13 +131,13 @@ public class JsonRpcHttpServiceTest {
     baseUrl = service.url();
   }
 
-  protected static JsonRpcHttpService createJsonRpcHttpService(final JsonRpcConfiguration config)
+  private static JsonRpcHttpService createJsonRpcHttpService(final JsonRpcConfiguration config)
       throws Exception {
     return new JsonRpcHttpService(
         vertx, folder.newFolder().toPath(), config, new NoOpMetricsSystem(), rpcMethods);
   }
 
-  protected static JsonRpcHttpService createJsonRpcHttpService() throws Exception {
+  private static JsonRpcHttpService createJsonRpcHttpService() throws Exception {
     return new JsonRpcHttpService(
         vertx,
         folder.newFolder().toPath(),
@@ -146,9 +146,10 @@ public class JsonRpcHttpServiceTest {
         rpcMethods);
   }
 
-  protected static JsonRpcConfiguration createJsonRpcConfig() {
+  private static JsonRpcConfiguration createJsonRpcConfig() {
     final JsonRpcConfiguration config = JsonRpcConfiguration.createDefault();
     config.setPort(0);
+    config.setHostsWhitelist(Collections.singletonList("*"));
     return config;
   }
 
@@ -170,18 +171,14 @@ public class JsonRpcHttpServiceTest {
 
   @Test
   public void http404() throws Exception {
-    final Request request = new Request.Builder().get().url(baseUrl + "/foo").build();
-
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildGetRequest("/foo")).execute()) {
       assertThat(resp.code()).isEqualTo(404);
     }
   }
 
   @Test
   public void handleEmptyRequest() throws Exception {
-    final Request request = new Request.Builder().get().url(baseUrl).build();
-
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildGetRequest("")).execute()) {
       assertThat(resp.code()).isEqualTo(201);
     }
   }
@@ -229,9 +226,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.header("Content-Type")).isEqualTo("application/json");
     }
   }
@@ -245,9 +241,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -265,9 +260,8 @@ public class JsonRpcHttpServiceTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"net_version\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -285,9 +279,8 @@ public class JsonRpcHttpServiceTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"eth_accounts\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -307,9 +300,8 @@ public class JsonRpcHttpServiceTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"net_peerCount\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -336,9 +328,8 @@ public class JsonRpcHttpServiceTest {
                 + ","
                 + params
                 + ",\"method\":\"eth_getUncleCountByBlockHash\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String jsonStr = resp.body().string();
@@ -365,9 +356,8 @@ public class JsonRpcHttpServiceTest {
                 + ","
                 + params
                 + ",\"method\":\"eth_getUncleCountByBlockHash\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String jsonStr = resp.body().string();
@@ -395,9 +385,8 @@ public class JsonRpcHttpServiceTest {
                 + ","
                 + params
                 + ",\"method\":\"eth_getUncleCountByBlockNumber\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -424,9 +413,8 @@ public class JsonRpcHttpServiceTest {
                 + ","
                 + params
                 + ",\"method\":\"eth_getUncleCountByBlockNumber\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -452,9 +440,8 @@ public class JsonRpcHttpServiceTest {
                 + ","
                 + params
                 + ",\"method\":\"eth_getUncleCountByBlockNumber\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -481,9 +468,8 @@ public class JsonRpcHttpServiceTest {
                 + ","
                 + params
                 + ",\"method\":\"eth_getUncleCountByBlockNumber\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -506,9 +492,8 @@ public class JsonRpcHttpServiceTest {
                 + ","
                 + params
                 + ",\"method\":\"eth_getUncleCountByBlockNumber\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -530,9 +515,8 @@ public class JsonRpcHttpServiceTest {
                 + ","
                 + params
                 + ",\"method\":\"eth_getUncleCountByBlockNumber\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -551,9 +535,8 @@ public class JsonRpcHttpServiceTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"net_peerCount\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -583,9 +566,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBalance\", \"params\": [\""
                 + address
                 + "\",\"latest\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -616,9 +598,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBalance\", \"params\": [\""
                 + address
                 + "\",\"latest\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -648,9 +629,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBalance\", \"params\": [\""
                 + address
                 + "\",\"earliest\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -683,9 +663,8 @@ public class JsonRpcHttpServiceTest {
                 + "\",\"0x"
                 + Long.toString(blockNumber, 16)
                 + "\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -711,12 +690,11 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": [\""
                 + blockHashString
                 + "\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
     // Setup mocks
     when(blockchainQueries.blockByHash(eq(blockHash))).thenReturn(Optional.empty());
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -747,9 +725,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": [\""
                 + blockHash
                 + "\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -780,9 +757,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": [\""
                 + blockHash
                 + "\",false]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -803,13 +779,12 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": [true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
     // Setup mocks
     when(blockchainQueries.blockByHash(ArgumentMatchers.isA(Hash.class)))
         .thenReturn(Optional.empty());
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -832,9 +807,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": [\""
                 + blockHashString
                 + "\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -856,9 +830,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": [\""
                 + blockHashString
                 + "\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -880,9 +853,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": [\""
                 + blockHashString
                 + "\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -905,9 +877,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": [\""
                 + blockHashString
                 + "\",{}]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -926,9 +897,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"eth_getBlockByHash\", \"params\": []}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -947,9 +917,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"eth_getBlockByHash\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -978,9 +947,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByNumber\", \"params\": [\"0x"
                 + Long.toString(number, 16)
                 + "\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1011,9 +979,8 @@ public class JsonRpcHttpServiceTest {
                 + ",\"method\":\"eth_getBlockByNumber\", \"params\": [\"0x"
                 + Long.toString(number, 16)
                 + "\",false]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1035,9 +1002,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"eth_getBlockByNumber\", \"params\": [\"bla\",false]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1065,9 +1031,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"eth_getBlockByNumber\", \"params\": [\"earliest\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1088,7 +1053,6 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"eth_getBlockByNumber\", \"params\": [\"0x0\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
     // Setup mocks to return a block
     final BlockDataGenerator gen = new BlockDataGenerator();
@@ -1097,7 +1061,7 @@ public class JsonRpcHttpServiceTest {
         blockWithMetadata(block);
     when(blockchainQueries.blockByNumber(eq(0L))).thenReturn(Optional.of(blockWithMetadata));
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1118,7 +1082,6 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"eth_getBlockByNumber\", \"params\": [\"latest\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
     // Setup mocks to return a block
     final BlockDataGenerator gen = new BlockDataGenerator();
@@ -1128,7 +1091,7 @@ public class JsonRpcHttpServiceTest {
     when(blockchainQueries.headBlockNumber()).thenReturn(0L);
     when(blockchainQueries.blockByNumber(eq(0L))).thenReturn(Optional.of(blockWithMetadata));
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1149,9 +1112,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"eth_getBlockByNumber\", \"params\": [\"pending\",true]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1172,9 +1134,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\", \"params\": [1,2,3]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -1191,9 +1152,8 @@ public class JsonRpcHttpServiceTest {
     final RequestBody body =
         RequestBody.create(
             JSON, "{\"id\":" + Json.encode(id) + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       final JsonObject json = new JsonObject(resp.body().string());
       testHelper.assertValidJsonRpcResult(json, id);
@@ -1207,9 +1167,8 @@ public class JsonRpcHttpServiceTest {
     // No id field is present - marking this as a notification
     final RequestBody body =
         RequestBody.create(JSON, "{\"jsonrpc\":\"2.0\",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       // Notifications return an empty response
       assertThat(resp.code()).isEqualTo(200);
       final String resBody = resp.body().string();
@@ -1223,9 +1182,8 @@ public class JsonRpcHttpServiceTest {
     final RequestBody body =
         RequestBody.create(
             JSON, "{\"jsonrpc\":\"2.0\",\"id\":null,\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -1245,9 +1203,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       // An empty string is still a string, so should be a valid id
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
@@ -1268,9 +1225,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -1293,9 +1249,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -1320,9 +1275,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -1342,9 +1296,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -1360,9 +1313,8 @@ public class JsonRpcHttpServiceTest {
     final RequestBody body =
         RequestBody.create(
             JSON, "{\"jsonrpc\":\"2.0\",\"id\":{},\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       final JsonObject json = new JsonObject(resp.body().string());
       final JsonRpcError expectedError = JsonRpcError.INVALID_REQUEST;
@@ -1376,9 +1328,8 @@ public class JsonRpcHttpServiceTest {
     final RequestBody body =
         RequestBody.create(
             JSON, "{\"jsonrpc\":\"2.0\",\"id\":[],\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       final JsonObject json = new JsonObject(resp.body().string());
       final JsonRpcError expectedError = JsonRpcError.INVALID_REQUEST;
@@ -1392,9 +1343,8 @@ public class JsonRpcHttpServiceTest {
     final Integer id = 2;
     final RequestBody body =
         RequestBody.create(JSON, "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + "}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       final JsonObject json = new JsonObject(resp.body().string());
       final JsonRpcError expectedError = JsonRpcError.INVALID_REQUEST;
@@ -1406,9 +1356,8 @@ public class JsonRpcHttpServiceTest {
   @Test
   public void invalidJson() throws Exception {
     final RequestBody body = RequestBody.create(JSON, "{bla");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       final JsonObject json = new JsonObject(resp.body().string());
       final JsonRpcError expectedError = JsonRpcError.PARSE_ERROR;
@@ -1420,9 +1369,8 @@ public class JsonRpcHttpServiceTest {
   @Test
   public void wrongJsonType() throws Exception {
     final RequestBody body = RequestBody.create(JSON, "\"a string\"");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       final JsonObject json = new JsonObject(resp.body().string());
       final JsonRpcError expectedError = JsonRpcError.PARSE_ERROR;
@@ -1440,9 +1388,8 @@ public class JsonRpcHttpServiceTest {
             "{\"jsonrpc\":\"1.0\",\"id\":"
                 + Json.encode(id)
                 + ",\"method\":\"web3_clientVersion\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       final JsonObject json = new JsonObject(resp.body().string());
       testHelper.assertValidJsonRpcResult(json, id);
@@ -1457,9 +1404,8 @@ public class JsonRpcHttpServiceTest {
     final RequestBody body =
         RequestBody.create(
             JSON, "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"bla\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       final JsonObject json = new JsonObject(resp.body().string());
       final JsonRpcError expectedError = JsonRpcError.METHOD_NOT_FOUND;
@@ -1479,9 +1425,8 @@ public class JsonRpcHttpServiceTest {
 
     final RequestBody body =
         RequestBody.create(JSON, "{\"jsonrpc\":\"2.0\",\"id\":\"666\",\"method\":\"foo\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(500);
     }
   }
@@ -1500,9 +1445,8 @@ public class JsonRpcHttpServiceTest {
             "[{\"jsonrpc\":\"2.0\",\"id\":\"000\",\"method\":\"web3_clientVersion\"},"
                 + "{\"jsonrpc\":\"2.0\",\"id\":\"111\",\"method\":\"foo\"},"
                 + "{\"jsonrpc\":\"2.0\",\"id\":\"222\",\"method\":\"net_version\"}]");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(500);
     }
   }
@@ -1524,9 +1468,8 @@ public class JsonRpcHttpServiceTest {
                 + "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(netVersionRequestId)
                 + ",\"method\":\"net_version\"}]");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonArray json = new JsonArray(resp.body().string());
@@ -1573,9 +1516,8 @@ public class JsonRpcHttpServiceTest {
             + ",\"method\":\"net_version\"}";
     final String batchRequest = "[" + String.join(", ", reqs) + "]";
     final RequestBody body = RequestBody.create(JSON, batchRequest);
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String jsonStr = resp.body().string();
@@ -1621,9 +1563,8 @@ public class JsonRpcHttpServiceTest {
             + "]";
 
     final RequestBody body = RequestBody.create(JSON, req);
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       final JsonObject json = new JsonObject(resp.body().string());
       final JsonRpcError expectedError = JsonRpcError.PARSE_ERROR;
@@ -1646,9 +1587,8 @@ public class JsonRpcHttpServiceTest {
                 + "{\"jsonrpc\":\"2.0\",\"id\":"
                 + Json.encode(netVersionRequestId)
                 + ",\"method\":\"net_version\"}]");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final JsonArray json = new JsonArray(resp.body().string());
@@ -1680,9 +1620,8 @@ public class JsonRpcHttpServiceTest {
   @Test
   public void emptyBatchRequest() throws Exception {
     final RequestBody body = RequestBody.create(JSON, "[]");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       final JsonObject json = new JsonObject(resp.body().string());
       final JsonRpcError expectedError = JsonRpcError.INVALID_REQUEST;
@@ -1812,10 +1751,9 @@ public class JsonRpcHttpServiceTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"eth_syncing\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
     when(synchronizer.getSyncStatus()).thenReturn(Optional.empty());
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Verify general result format.
       final JsonObject json = new JsonObject(resp.body().string());
@@ -1834,9 +1772,8 @@ public class JsonRpcHttpServiceTest {
         RequestBody.create(
             JSON,
             "{\"jsonrpc\":\"2.0\",\"id\":" + Json.encode(id) + ",\"method\":\"eth_syncing\"}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       final String respBody = resp.body().string();
       final JsonObject json = new JsonObject(respBody);
       final JsonObject result = json.getJsonObject("result");
@@ -1902,9 +1839,8 @@ public class JsonRpcHttpServiceTest {
                 + "\",\""
                 + UInt256.ZERO
                 + "\",\"latest\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1938,9 +1874,8 @@ public class JsonRpcHttpServiceTest {
                 + "\",\""
                 + UInt256.ONE
                 + "\",\"latest\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -1973,9 +1908,8 @@ public class JsonRpcHttpServiceTest {
                 + "\",\""
                 + UInt256.ONE
                 + "\",\"earliest\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -2010,9 +1944,8 @@ public class JsonRpcHttpServiceTest {
                 + "\",\""
                 + 0L
                 + "\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(200);
       // Check general format of result
       final String respBody = resp.body().string();
@@ -2043,9 +1976,8 @@ public class JsonRpcHttpServiceTest {
                 + "\",\""
                 + "blah"
                 + "\",\"latest\"]}");
-    final Request request = new Request.Builder().post(body).url(baseUrl).build();
 
-    try (final Response resp = client.newCall(request).execute()) {
+    try (final Response resp = client.newCall(buildPostRequest(body)).execute()) {
       assertThat(resp.code()).isEqualTo(400);
       // Check general format of result
       final JsonObject json = new JsonObject(resp.body().string());
@@ -2054,4 +1986,12 @@ public class JsonRpcHttpServiceTest {
           json, id, expectedError.getCode(), expectedError.getMessage());
     }
   }
+
+  private Request buildPostRequest(final RequestBody body) {
+    return new Request.Builder().post(body).url(baseUrl).build();
+  }
+
+  private Request buildGetRequest(final String path) {
+    return new Request.Builder().get().url(baseUrl + path).build();
+  }
 }

pantheon/src/main/java/tech/pegasys/pantheon/cli/PantheonCommand.java

@@ -19,6 +19,7 @@ import static tech.pegasys.pantheon.cli.DefaultCommandValues.getDefaultPantheonD
 import tech.pegasys.pantheon.Runner;
 import tech.pegasys.pantheon.RunnerBuilder;
 import tech.pegasys.pantheon.cli.custom.CorsAllowedOriginsProperty;
+import tech.pegasys.pantheon.cli.custom.JsonRPCWhitelistHostsProperty;
 import tech.pegasys.pantheon.consensus.clique.jsonrpc.CliqueRpcApis;
 import tech.pegasys.pantheon.consensus.ibft.jsonrpc.IbftRpcApis;
 import tech.pegasys.pantheon.controller.KeyPairUtil;
@@ -311,6 +312,16 @@ public class PantheonCommand implements DefaultCommandValues, Runnable {
   )
   private final Collection<RpcApi> wsApis = null;
 
+  @Option(
+    names = {"--host-whitelist"},
+    paramLabel = "<hostname>",
+    description =
+        "Comma separated list of hostnames to whitelist for RPC access.  default: ${DEFAULT-VALUE}",
+    defaultValue = "localhost",
+    converter = JsonRPCWhitelistHostsProperty.JsonRPCWhitelistHostsConverter.class
+  )
+  private final JsonRPCWhitelistHostsProperty hostsWhitelist = new JsonRPCWhitelistHostsProperty();
+
   @Option(
     names = {"--dev-mode"},
     description =
@@ -483,6 +494,7 @@ public class PantheonCommand implements DefaultCommandValues, Runnable {
     jsonRpcConfiguration.setPort(rpcHostAndPort.getPort());
     jsonRpcConfiguration.setCorsAllowedDomains(rpcCorsAllowedOrigins.getDomains());
     jsonRpcConfiguration.setRpcApis(rpcApis);
+    jsonRpcConfiguration.setHostsWhitelist(hostsWhitelist.hostnamesWhitelist());
     return jsonRpcConfiguration;
   }
 

pantheon/src/main/java/tech/pegasys/pantheon/cli/custom/JsonRPCWhitelistHostsProperty.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2018 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.pantheon.cli.custom;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import picocli.CommandLine;
+
+public class JsonRPCWhitelistHostsProperty {
+  private List<String> hostnamesWhitelist = Collections.emptyList();
+
+  private JsonRPCWhitelistHostsProperty(final List<String> hostnamesWhitelist) {
+    this.hostnamesWhitelist = hostnamesWhitelist;
+  }
+
+  public JsonRPCWhitelistHostsProperty() {}
+
+  public List<String> hostnamesWhitelist() {
+    return hostnamesWhitelist;
+  }
+
+  public static class JsonRPCWhitelistHostsConverter
+      implements CommandLine.ITypeConverter<JsonRPCWhitelistHostsProperty> {
+
+    @Override
+    public JsonRPCWhitelistHostsProperty convert(final String value) {
+      final List<String> hostNames;
+      if (value != null && !value.isEmpty()) {
+        hostNames = new ArrayList<>(Arrays.asList(value.split("\\s*,\\s*")));
+      } else {
+        throw new IllegalArgumentException("Property can't be null/empty string");
+      }
+
+      if (hostNames.contains("all")) {
+        if (hostNames.size() > 1) {
+          throw new IllegalArgumentException("Value 'all' can't be used with other hostnames");
+        } else {
+          return new JsonRPCWhitelistHostsProperty(Collections.singletonList("*"));
+        }
+      }
+
+      if (hostNames.contains("*")) {
+        if (hostNames.size() > 1) {
+          throw new IllegalArgumentException("Value '*' can't be used with other hostnames");
+        } else {
+          return new JsonRPCWhitelistHostsProperty(Collections.singletonList("*"));
+        }
+      }
+
+      if (hostNames.size() > 0) {
+        return new JsonRPCWhitelistHostsProperty(hostNames);
+      } else {
+        return new JsonRPCWhitelistHostsProperty();
+      }
+    }
+  }
+}

pantheon/src/test/java/tech/pegasys/pantheon/RunnerTest.java

@@ -252,6 +252,7 @@ public final class RunnerTest {
     final JsonRpcConfiguration configuration = JsonRpcConfiguration.createDefault();
     configuration.setPort(0);
     configuration.setEnabled(true);
+    configuration.setHostsWhitelist(Collections.singletonList("*"));
     return configuration;
   }
 
@@ -263,8 +264,7 @@ public final class RunnerTest {
   }
 
   private PermissioningConfiguration permissioningConfiguration() {
-    final PermissioningConfiguration configuration = PermissioningConfiguration.createDefault();
-    return configuration;
+    return PermissioningConfiguration.createDefault();
   }
 
   private static void setupState(

pantheon/src/test/java/tech/pegasys/pantheon/cli/PantheonCommandTest.java

@@ -707,6 +707,62 @@ public class PantheonCommandTest extends CommandTestAbstract {
         .contains("Domain values result in invalid regex pattern");
   }
 
+  @Test
+  public void jsonRpcHostWhitelistAcceptsSingleArgument() {
+    parseCommand("--host-whitelist", "a");
+
+    verify(mockRunnerBuilder).jsonRpcConfiguration(jsonRpcConfigArgumentCaptor.capture());
+    verify(mockRunnerBuilder).build();
+
+    assertThat(jsonRpcConfigArgumentCaptor.getValue().getHostsWhitelist().size()).isEqualTo(1);
+    assertThat(jsonRpcConfigArgumentCaptor.getValue().getHostsWhitelist()).contains("a");
+    assertThat(jsonRpcConfigArgumentCaptor.getValue().getHostsWhitelist())
+        .doesNotContain("localhost");
+
+    assertThat(commandOutput.toString()).isEmpty();
+    assertThat(commandErrorOutput.toString()).isEmpty();
+  }
+
+  @Test
+  public void jsonRpcHostWhitelistAcceptsMultipleArguments() {
+    parseCommand("--host-whitelist", "a,b");
+
+    verify(mockRunnerBuilder).jsonRpcConfiguration(jsonRpcConfigArgumentCaptor.capture());
+    verify(mockRunnerBuilder).build();
+
+    assertThat(jsonRpcConfigArgumentCaptor.getValue().getHostsWhitelist().size()).isEqualTo(2);
+    assertThat(jsonRpcConfigArgumentCaptor.getValue().getHostsWhitelist()).contains("a", "b");
+    assertThat(jsonRpcConfigArgumentCaptor.getValue().getHostsWhitelist())
+        .doesNotContain("*", "localhost");
+
+    assertThat(commandOutput.toString()).isEmpty();
+    assertThat(commandErrorOutput.toString()).isEmpty();
+  }
+
+  @Test
+  public void jsonRpcHostWhitelistStarWithAnotherHostnameMustFail() {
+    final String[] origins = {"friend", "*"};
+    parseCommand("--host-whitelist", String.join(",", origins));
+
+    verifyZeroInteractions(mockRunnerBuilder);
+
+    assertThat(commandOutput.toString()).isEmpty();
+    assertThat(commandErrorOutput.toString())
+        .contains("Value '*' can't be used with other hostnames");
+  }
+
+  @Test
+  public void jsonRpcHostWhitelistAllWithAnotherHostnameMustFail() {
+    final String[] origins = {"friend", "all"};
+    parseCommand("--host-whitelist", String.join(",", origins));
+
+    verifyZeroInteractions(mockRunnerBuilder);
+
+    assertThat(commandOutput.toString()).isEmpty();
+    assertThat(commandErrorOutput.toString())
+        .contains("Value 'all' can't be used with other hostnames");
+  }
+
   @Test
   public void wsRpcEnabledPropertyDefaultIsFalse() {
     parseCommand();

quickstart/src/test/java/tech/pegasys/pantheon/tests/quickstart/DockerQuickstartTest.java

@@ -57,6 +57,7 @@ public class DockerQuickstartTest {
   private static final String DEFAULT_RPC_HOST =
       Optional.ofNullable(System.getenv("DOCKER_PORT_2375_TCP_ADDR")).orElse("localhost");
   private static final String DEFAULT_HTTP_RPC_HOST = "http://" + DEFAULT_RPC_HOST;
+  private static final String DEFAULT_HOST_HEADER = "localhost";
   private final Map<ServicesIdentifier, Service> services = new EnumMap<>(ServicesIdentifier.class);
   private final Map<EndpointsIdentifier, String> endpoints =
       new EnumMap<>(EndpointsIdentifier.class);
@@ -104,8 +105,7 @@ public class DockerQuickstartTest {
     assertThat(services).isNotNull().isNotEmpty();
     assertThat(endpoints).isNotNull().isNotEmpty();
 
-    web3HttpClient =
-        Web3j.build(
+    HttpService httpService =
         new HttpService(
             DEFAULT_HTTP_RPC_HOST
                 + ":"
@@ -113,10 +113,9 @@ public class DockerQuickstartTest {
                     .get(ServicesIdentifier.RPCNODE)
                     .exposedPorts
                     .get(DEFAULT_HTTP_RPC_PORT)
-                        .externalPort),
-            2000,
-            Async.defaultExecutorService());
-
+                    .externalPort);
+    httpService.addHeader("Host", DEFAULT_HOST_HEADER);
+    web3HttpClient = Web3j.build(httpService, 2000, Async.defaultExecutorService());
     assertThat(web3HttpClient).isNotNull();
   }