CORDA-3464: Also scan attachment:// URLs for custom serializers. (#5771)

* CORDA-3464: Also scan attachment:// URLs for custom serializers.

* Only scan the given classloader - ignore this classloader's parents.

* Upgrade to ClassGraph 4.8.58 - for "robustness fxes".

* Update how we scan for test CorDapps with latest ClassGraph.

* Register the attachment:// URL scheme using AttachmentsClassLoader.

* Add integration test for custom serializer in contract state.

* Rename Currancy -> Currantsy, just to make the point.

build.gradle

@@ -70,7 +70,7 @@ buildscript {
     ext.commons_cli_version = '1.4'
     ext.protonj_version = '0.33.0' // Overide Artemis version
     ext.snappy_version = '0.4'
-    ext.class_graph_version = '4.6.12'
+    ext.class_graph_version = constants.getProperty('classgraphVersion')
     ext.jcabi_manifests_version = '1.1'
     ext.picocli_version = '3.8.0'
     ext.commons_io_version = '2.6'

client/rpc/src/main/kotlin/net/corda/client/rpc/internal/serialization/amqp/AMQPClientSerializationScheme.kt

@@ -21,11 +21,16 @@ class AMQPClientSerializationScheme(
         cordappSerializationWhitelists: Set<SerializationWhitelist>,
         serializerFactoriesForContexts: MutableMap<SerializationFactoryCacheKey, SerializerFactory>
     ) : AbstractAMQPSerializationScheme(cordappCustomSerializers, cordappSerializationWhitelists, serializerFactoriesForContexts) {
-    constructor(cordapps: List<Cordapp>) : this(cordapps.customSerializers, cordapps.serializationWhitelists, AccessOrderLinkedHashMap<SerializationFactoryCacheKey, SerializerFactory>(128).toSynchronised())
-    constructor(cordapps: List<Cordapp>, serializerFactoriesForContexts: MutableMap<SerializationFactoryCacheKey, SerializerFactory>) : this(cordapps.customSerializers, cordapps.serializationWhitelists, serializerFactoriesForContexts)
+    constructor(cordapps: List<Cordapp>) : this(cordapps.customSerializers, cordapps.serializationWhitelists)
+    constructor(cordapps: List<Cordapp>, serializerFactoriesForContexts: MutableMap<SerializationFactoryCacheKey, SerializerFactory>)
+        : this(cordapps.customSerializers, cordapps.serializationWhitelists, serializerFactoriesForContexts)
+    constructor(
+        cordappCustomSerializers: Set<SerializationCustomSerializer<*,*>>,
+        cordappSerializationWhitelists: Set<SerializationWhitelist>
+    ) : this(cordappCustomSerializers, cordappSerializationWhitelists, createDefaultSerializerFactoryCache())
 
     @Suppress("UNUSED")
-    constructor() : this(emptySet(), emptySet(), AccessOrderLinkedHashMap<SerializationFactoryCacheKey, SerializerFactory>(128).toSynchronised())
+    constructor() : this(emptySet(), emptySet())
 
     companion object {
         /** Call from main only. */
@@ -44,6 +49,10 @@ class AMQPClientSerializationScheme(
                     rpcServerContext = AMQP_RPC_SERVER_CONTEXT
             )
         }
+
+        private fun createDefaultSerializerFactoryCache(): MutableMap<SerializationFactoryCacheKey, SerializerFactory> {
+            return AccessOrderLinkedHashMap<SerializationFactoryCacheKey, SerializerFactory>(128).toSynchronised()
+        }
     }
 
     override fun canDeserializeVersion(magic: CordaSerializationMagic, target: SerializationContext.UseCase): Boolean {

constants.properties

@@ -15,6 +15,7 @@ guavaVersion=25.1-jre
 quasarVersion=0.7.10
 proguardVersion=6.0.3
 bouncycastleVersion=1.60
+classgraphVersion=4.8.58
 disruptorVersion=3.4.2
 typesafeConfigVersion=1.3.3
 jsr305Version=3.0.2

core/build.gradle

@@ -113,6 +113,8 @@ dependencies {
     compile "org.hibernate:hibernate-core:$hibernate_version"
 
     compile group: "io.github.classgraph", name: "classgraph", version: class_graph_version
+
+    testCompile "org.ow2.asm:asm:$asm_version"
 }
 
 // TODO Consider moving it to quasar-utils in the future (introduced with PR-1388)

core/src/main/kotlin/net/corda/core/internal/ClassLoadingUtils.kt

@@ -1,7 +1,9 @@
 package net.corda.core.internal
 
 import io.github.classgraph.ClassGraph
+import io.github.classgraph.ClassInfo
 import net.corda.core.StubOutForDJVM
+import net.corda.core.serialization.internal.AttachmentURLStreamHandlerFactory.attachmentScheme
 
 /**
  * Creates instances of all the classes in the classpath of the provided classloader, which implement the interface of the provided class.
@@ -17,16 +19,17 @@ import net.corda.core.StubOutForDJVM
  */
 @StubOutForDJVM
 fun <T: Any> createInstancesOfClassesImplementing(classloader: ClassLoader, clazz: Class<T>): Set<T> {
-    return ClassGraph().addClassLoader(classloader)
-            .enableClassInfo()
-            .pooledScan()
-            .use {
-                it.getClassesImplementing(clazz.name)
-                        .filterNot { it.isAbstract }
-                        .map { classloader.loadClass(it.name).asSubclass(clazz) }
-                        .map { it.kotlin.objectOrNewInstance() }
-                        .toSet()
-            }
+    return ClassGraph().overrideClassLoaders(classloader)
+        .enableURLScheme(attachmentScheme)
+        .ignoreParentClassLoaders()
+        .enableClassInfo()
+        .pooledScan()
+        .use { result ->
+            result.getClassesImplementing(clazz.name)
+                .filterNot(ClassInfo::isAbstract)
+                .map { classloader.loadClass(it.name).asSubclass(clazz) }
+                .mapTo(LinkedHashSet()) { it.kotlin.objectOrNewInstance() }
+        }
 }
 
 fun <T: Any?> executeWithThreadContextClassLoader(classloader: ClassLoader, fn: () -> T): T {

core/src/main/kotlin/net/corda/core/serialization/internal/AttachmentsClassLoader.kt

@@ -346,7 +346,7 @@ object AttachmentsClassLoaderBuilder {
  * This will not be exposed as an API.
  */
 object AttachmentURLStreamHandlerFactory : URLStreamHandlerFactory {
-    private const val attachmentScheme = "attachment"
+    internal const val attachmentScheme = "attachment"
 
     // TODO - what happens if this grows too large?
     private val loadedAttachments = mutableMapOf<String, Attachment>().toSynchronised()

core/src/test/kotlin/net/corda/core/internal/AsmTools.kt

@@ -0,0 +1,31 @@
+@file:JvmName("AsmTools")
+package net.corda.core.internal
+
+import org.objectweb.asm.ClassReader
+import org.objectweb.asm.ClassVisitor
+import org.objectweb.asm.ClassWriter
+import org.objectweb.asm.ClassWriter.COMPUTE_MAXS
+import org.objectweb.asm.Opcodes.ASM5
+
+val String.asInternalName: String get() = replace('.', '/')
+val Class<*>.resourceName: String get() = "${name.asInternalName}.class"
+val Class<*>.byteCode: ByteArray get() = classLoader.getResourceAsStream(resourceName)!!.use {
+    it.readBytes()
+}
+
+fun Class<*>.renameTo(newName: String): ByteArray {
+    return byteCode.accept { w -> RenamingWriter(newName, w) }
+}
+
+fun ByteArray.accept(visitor: (ClassVisitor) -> ClassVisitor): ByteArray {
+    return ClassWriter(COMPUTE_MAXS).let { writer ->
+        ClassReader(this).accept(visitor(writer), 0)
+        writer.toByteArray()
+    }
+}
+
+private class RenamingWriter(private val newName: String, visitor: ClassVisitor) : ClassVisitor(ASM5, visitor) {
+    override fun visit(version: Int, access: Int, name: String, signature: String?, superName: String?, interfaces: Array<out String>?) {
+        super.visit(version, access, newName, signature, superName, interfaces)
+    }
+}

core/src/test/kotlin/net/corda/core/internal/ClassLoadingUtilsTest.kt

@@ -1,25 +1,62 @@
 package net.corda.core.internal
 
 import com.nhaarman.mockito_kotlin.mock
+import net.corda.core.contracts.ContractAttachment
+import net.corda.core.contracts.ContractClassName
+import net.corda.core.crypto.SecureHash
+import net.corda.core.identity.Party
+import net.corda.core.serialization.internal.AttachmentURLStreamHandlerFactory
+import net.corda.core.serialization.internal.AttachmentsClassLoader
 import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.Assertions.assertThatThrownBy
+import org.junit.Assert.assertEquals
 import org.junit.Test
-import java.lang.IllegalArgumentException
-import java.lang.RuntimeException
+import java.io.ByteArrayOutputStream
+import java.net.URLClassLoader
+import java.security.PublicKey
+import java.util.jar.JarOutputStream
+import java.util.jar.Manifest
+import java.util.zip.Deflater.NO_COMPRESSION
+import java.util.zip.ZipEntry
+import java.util.zip.ZipEntry.DEFLATED
+import java.util.zip.ZipEntry.STORED
 
 class ClassLoadingUtilsTest {
+    companion object {
+        const val STANDALONE_CLASS_NAME = "com.example.StandaloneClassWithEmptyConstructor"
+        const val PROGRAM_ID: ContractClassName = "net.corda.core.internal.DummyContract"
+        val contractAttachmentId = SecureHash.randomSHA256()
+
+        fun directoryEntry(internalName: String) = ZipEntry("$internalName/").apply {
+            method = STORED
+            compressedSize = 0
+            size = 0
+            crc = 0
+        }
+
+        fun classEntry(internalName: String) = ZipEntry("$internalName.class").apply {
+            method = DEFLATED
+        }
+
+        init {
+            // Register the "attachment://" URL scheme.
+            // You may only register new schemes ONCE per JVM!
+            AttachmentsClassLoader
+        }
+    }
 
     private val temporaryClassLoader = mock<ClassLoader>()
 
-    interface BaseInterface {}
+    interface BaseInterface
 
-    interface BaseInterface2 {}
+    interface BaseInterface2
 
-    class ConcreteClassWithEmptyConstructor: BaseInterface {}
+    class ConcreteClassWithEmptyConstructor: BaseInterface
 
     abstract class AbstractClass: BaseInterface
 
-    class ConcreteClassWithNonEmptyConstructor(private val someData: Int): BaseInterface2 {}
+    @Suppress("unused")
+    class ConcreteClassWithNonEmptyConstructor(private val someData: Int): BaseInterface2
 
     @Test
     fun predicateClassAreLoadedSuccessfully() {
@@ -27,8 +64,9 @@ class ClassLoadingUtilsTest {
 
         val classNames = classes.map { it.javaClass.name }
 
-        assertThat(classNames).contains(ConcreteClassWithEmptyConstructor::class.java.name)
-        assertThat(classNames).doesNotContain(AbstractClass::class.java.name)
+        assertThat(classNames)
+            .contains(ConcreteClassWithEmptyConstructor::class.java.name)
+            .doesNotContain(AbstractClass::class.java.name)
     }
 
     @Test(expected = IllegalArgumentException::class)
@@ -56,4 +94,42 @@ class ClassLoadingUtilsTest {
         assertThat(Thread.currentThread().contextClassLoader).isNotEqualTo(temporaryClassLoader)
     }
 
-}
+    @Test
+    fun `test locating classes inside attachment`() {
+        val jarData = with(ByteArrayOutputStream()) {
+            val internalName = STANDALONE_CLASS_NAME.asInternalName
+            JarOutputStream(this, Manifest()).use {
+                it.setLevel(NO_COMPRESSION)
+                it.setMethod(DEFLATED)
+                it.putNextEntry(directoryEntry("com"))
+                it.putNextEntry(directoryEntry("com/example"))
+                it.putNextEntry(classEntry(internalName))
+                it.write(TemplateClassWithEmptyConstructor::class.java.renameTo(internalName))
+            }
+            toByteArray()
+        }
+        val attachment = signedAttachment(jarData)
+        val url = AttachmentURLStreamHandlerFactory.toUrl(attachment)
+
+        URLClassLoader(arrayOf(url)).use { cordappClassLoader ->
+            val standaloneClass = createInstancesOfClassesImplementing(cordappClassLoader, BaseInterface::class.java)
+                .map(Any::javaClass)
+                .single()
+            assertEquals(STANDALONE_CLASS_NAME, standaloneClass.name)
+            assertEquals(cordappClassLoader, standaloneClass.classLoader)
+        }
+    }
+
+    private fun signedAttachment(data: ByteArray, vararg parties: Party) = ContractAttachment.create(
+        object : AbstractAttachment({ data }, "test") {
+            override val id: SecureHash get() = contractAttachmentId
+
+            override val signerKeys: List<PublicKey> get() = parties.map(Party::owningKey)
+        }, PROGRAM_ID, signerKeys = parties.map(Party::owningKey)
+    )
+}
+
+// Our dummy attachment will contain a class that is created from this one.
+// This is because our attachment must contain a class that DOES NOT exist
+// inside the application classloader.
+class TemplateClassWithEmptyConstructor : ClassLoadingUtilsTest.BaseInterface

node/src/integration-test/kotlin/net/corda/contracts/serialization/custom/CurrantsySerializer.kt

@@ -0,0 +1,21 @@
+package net.corda.contracts.serialization.custom
+
+import net.corda.core.serialization.SerializationCustomSerializer
+
+@Suppress("unused")
+class CurrantsySerializer : SerializationCustomSerializer<Currantsy, CurrantsySerializer.Proxy> {
+    data class Proxy(val currants: Long)
+
+    override fun fromProxy(proxy: Proxy): Currantsy = Currantsy(proxy.currants)
+    override fun toProxy(obj: Currantsy) = Proxy(obj.currants)
+}
+
+data class Currantsy(val currants: Long) : Comparable<Currantsy> {
+    override fun toString(): String {
+        return "$currants juicy currants"
+    }
+
+    override fun compareTo(other: Currantsy): Int {
+        return currants.compareTo(other.currants)
+    }
+}

node/src/integration-test/kotlin/net/corda/contracts/serialization/custom/CustomSerializerContract.kt

@@ -0,0 +1,39 @@
+package net.corda.contracts.serialization.custom
+
+import net.corda.core.contracts.CommandData
+import net.corda.core.contracts.Contract
+import net.corda.core.contracts.ContractState
+import net.corda.core.identity.AbstractParty
+import net.corda.core.transactions.LedgerTransaction
+
+@Suppress("unused")
+class CustomSerializerContract : Contract {
+    companion object {
+        const val MAX_CURRANT = 2000
+    }
+
+    override fun verify(tx: LedgerTransaction) {
+        val currantsyData = tx.outputsOfType(CurrantsyState::class.java)
+        require(currantsyData.isNotEmpty()) {
+            "Requires at least one currantsy state"
+        }
+
+        currantsyData.forEach {
+            require(it.currantsy.currants in 0..MAX_CURRANT) {
+                "Too many currants! ${it.currantsy.currants} is unraisinable!"
+            }
+        }
+    }
+
+    @Suppress("CanBeParameter", "MemberVisibilityCanBePrivate")
+    class CurrantsyState(val owner: AbstractParty, val currantsy: Currantsy) : ContractState {
+        override val participants: List<AbstractParty> = listOf(owner)
+
+        @Override
+        override fun toString(): String {
+            return currantsy.toString()
+        }
+    }
+
+    class Purchase : CommandData
+}

node/src/integration-test/kotlin/net/corda/contracts/serialization/custom/CustomSerializerRegistry.kt

@@ -0,0 +1,7 @@
+package net.corda.contracts.serialization.custom
+
+import net.corda.core.serialization.SerializationWhitelist
+
+class CustomSerializerRegistry : SerializationWhitelist {
+    override val whitelist: List<Class<*>> = listOf(Currantsy::class.java)
+}

node/src/integration-test/kotlin/net/corda/flows/serialization/custom/CustomSerializerFlow.kt

@@ -0,0 +1,30 @@
+package net.corda.flows.serialization.custom
+
+import co.paralleluniverse.fibers.Suspendable
+import net.corda.contracts.serialization.custom.Currantsy
+import net.corda.contracts.serialization.custom.CustomSerializerContract.CurrantsyState
+import net.corda.contracts.serialization.custom.CustomSerializerContract.Purchase
+import net.corda.core.contracts.Command
+import net.corda.core.crypto.SecureHash
+import net.corda.core.flows.FlowLogic
+import net.corda.core.flows.InitiatingFlow
+import net.corda.core.flows.StartableByRPC
+import net.corda.core.transactions.TransactionBuilder
+
+@InitiatingFlow
+@StartableByRPC
+class CustomSerializerFlow(
+    private val purchase: Currantsy
+) : FlowLogic<SecureHash>() {
+    @Suspendable
+    override fun call(): SecureHash {
+        val notary = serviceHub.networkMapCache.notaryIdentities[0]
+        val stx = serviceHub.signInitialTransaction(
+            TransactionBuilder(notary)
+                .addOutputState(CurrantsyState(ourIdentity, purchase))
+                .addCommand(Command(Purchase(), ourIdentity.owningKey))
+        )
+        stx.verify(serviceHub, checkSufficientSignatures = false)
+        return stx.id
+    }
+}

node/src/integration-test/kotlin/net/corda/node/ContractWithCustomSerializerTest.kt

@@ -0,0 +1,57 @@
+package net.corda.node
+
+import net.corda.client.rpc.CordaRPCClient
+import net.corda.contracts.serialization.custom.Currantsy
+import net.corda.core.contracts.TransactionVerificationException
+import net.corda.core.messaging.startFlow
+import net.corda.core.utilities.getOrThrow
+import net.corda.flows.serialization.custom.CustomSerializerFlow
+import net.corda.node.services.Permissions
+import net.corda.testing.core.ALICE_NAME
+import net.corda.testing.core.DUMMY_NOTARY_NAME
+import net.corda.testing.driver.DriverParameters
+import net.corda.testing.driver.driver
+import net.corda.testing.driver.internal.incrementalPortAllocation
+import net.corda.testing.node.NotarySpec
+import net.corda.testing.node.User
+import net.corda.testing.node.internal.CustomCordapp
+import net.corda.testing.node.internal.cordappWithPackages
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+import kotlin.test.assertFailsWith
+
+@Suppress("FunctionName")
+class ContractWithCustomSerializerTest {
+    companion object {
+        const val CURRANTS = 5000L
+        const val DEFAULT_STARTING_PORT = 10000
+    }
+
+    @Test
+    fun `flow with custom serializer by rpc`() {
+        val user = User("u", "p", setOf(Permissions.all()))
+        driver(DriverParameters(
+            portAllocation = incrementalPortAllocation(DEFAULT_STARTING_PORT),
+            startNodesInProcess = false,
+            notarySpecs = listOf(NotarySpec(DUMMY_NOTARY_NAME, validating = true)),
+            cordappsForAllNodes = listOf(
+                cordappWithPackages("net.corda.flows.serialization.custom"),
+                CustomCordapp(
+                    packages = setOf("net.corda.contracts.serialization.custom"),
+                    name = "has-custom-serializer"
+                ).signed()
+            )
+        )) {
+            val alice = startNode(providedName = ALICE_NAME, rpcUsers = listOf(user)).getOrThrow()
+            val ex = assertFailsWith<TransactionVerificationException> {
+                CordaRPCClient(hostAndPort = alice.rpcAddress)
+                    .start(user.username, user.password)
+                    .proxy
+                    .startFlow(::CustomSerializerFlow, Currantsy(CURRANTS))
+                    .returnValue
+                    .getOrThrow()
+            }
+            assertThat(ex).hasMessageContaining("Too many currants! $CURRANTS is unraisinable!")
+        }
+    }
+}

testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/CustomCordapp.kt

@@ -4,6 +4,7 @@ import io.github.classgraph.ClassGraph
 import net.corda.core.internal.*
 import net.corda.core.internal.cordapp.CordappImpl
 import net.corda.core.internal.cordapp.set
+import net.corda.core.serialization.SerializationWhitelist
 import net.corda.core.utilities.contextLogger
 import net.corda.core.utilities.debug
 import net.corda.testing.core.internal.JarSignatureTestUtils.generateKey
@@ -55,10 +56,19 @@ data class CustomCordapp(
                 .pooledScan()
 
         scanResult.use {
+            val whitelistService = SerializationWhitelist::class.java.name
+            val whitelists = it.getClassesImplementing(whitelistService)
+
             JarOutputStream(file.outputStream()).use { jos ->
                 jos.addEntry(testEntry(JarFile.MANIFEST_NAME)) {
                     createTestManifest(name, versionId, targetPlatformVersion).write(jos)
                 }
+                if (whitelists.isNotEmpty()) {
+                    jos.addEntry(directoryEntry("META-INF/services"))
+                    jos.addEntry(testEntry("META-INF/services/$whitelistService")) {
+                        jos.write(whitelists.names.joinToString(separator = "\r\n").toByteArray())
+                    }
+                }
 
                 // The same resource may be found in different locations (this will happen when running from gradle) so just
                 // pick the first one found.
@@ -109,6 +119,16 @@ data class CustomCordapp(
         return ZipEntry(name).setCreationTime(epochFileTime).setLastAccessTime(epochFileTime).setLastModifiedTime(epochFileTime)
     }
 
+    private fun directoryEntry(name: String): ZipEntry {
+        val directoryName = if (name.endsWith('/')) name else "$name/"
+        return testEntry(directoryName).apply {
+            method = ZipEntry.STORED
+            compressedSize = 0
+            size = 0
+            crc = 0
+        }
+    }
+
     data class SigningInfo(val keyStorePath: Path? = null)
 
     companion object {

testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/DriverDSLImpl.kt

@@ -111,6 +111,12 @@ class DriverDSLImpl(
     private lateinit var _notaries: CordaFuture<List<NotaryHandle>>
     override val notaryHandles: List<NotaryHandle> get() = _notaries.getOrThrow()
 
+    override val cordappsClassLoader: ClassLoader? = if (!startNodesInProcess) {
+        createCordappsClassLoader(cordappsForAllNodes)
+    } else {
+        null
+    }
+
     // While starting with inProcess mode, we need to have different names to avoid clashes
     private val inMemoryCounter = AtomicInteger()
 
@@ -159,6 +165,7 @@ class DriverDSLImpl(
         }
         _shutdownManager?.shutdown()
         _executorService?.shutdownNow()
+        (cordappsClassLoader as? AutoCloseable)?.close()
     }
 
     private fun establishRpc(config: NodeConfig, processDeathFuture: CordaFuture<out Process>): CordaFuture<CordaRPCOps> {
@@ -834,6 +841,13 @@ class DriverDSLImpl(
             return config
         }
 
+        private fun createCordappsClassLoader(cordapps: Collection<TestCordappInternal>?): ClassLoader? {
+            if (cordapps == null || cordapps.isEmpty()) {
+                return null
+            }
+            return URLClassLoader(cordapps.map { it.jarFile.toUri().toURL() }.toTypedArray())
+        }
+
         private operator fun Config.plus(property: Pair<String, Any>) = withValue(property.first, ConfigValueFactory.fromAnyRef(property.second))
 
         /**
@@ -921,6 +935,8 @@ interface InternalDriverDSL : DriverDSL {
 
     val shutdownManager: ShutdownManager
 
+    val cordappsClassLoader: ClassLoader?
+
     fun baseDirectory(nodeName: String): Path = baseDirectory(CordaX500Name.parse(nodeName))
 
     /**
@@ -960,7 +976,7 @@ fun <DI : DriverDSL, D : InternalDriverDSL, A> genericDriver(
         coerce: (D) -> DI,
         dsl: DI.() -> A
 ): A {
-    val serializationEnv = setDriverSerialization()
+    val serializationEnv = setDriverSerialization(driverDsl.cordappsClassLoader)
     val shutdownHook = addShutdownHook(driverDsl::shutdown)
     try {
         driverDsl.start()

testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/InternalTestUtils.kt

@@ -255,15 +255,18 @@ fun DriverDSL.assertCheckpoints(name: CordaX500Name, expected: Long) {
 /**
  * Should only be used by Driver and MockNode.
  */
-fun setDriverSerialization(): AutoCloseable? {
+fun setDriverSerialization(classLoader: ClassLoader?): AutoCloseable? {
     return if (_allEnabledSerializationEnvs.isEmpty()) {
-        DriverSerializationEnvironment().enable()
+        DriverSerializationEnvironment(classLoader).enable()
     } else {
         null
     }
 }
 
-private class DriverSerializationEnvironment : SerializationEnvironment by createTestSerializationEnv(), AutoCloseable {
+fun setDriverSerialization(): AutoCloseable? = setDriverSerialization(null)
+
+private class DriverSerializationEnvironment(classLoader: ClassLoader?)
+                  : SerializationEnvironment by createTestSerializationEnv(classLoader), AutoCloseable {
     fun enable() = apply { _driverSerializationEnv.set(this) }
     override fun close() {
         _driverSerializationEnv.set(null)
@@ -276,6 +279,8 @@ fun JarOutputStream.addEntry(entry: ZipEntry, input: InputStream) {
     addEntry(entry) { input.use { it.copyTo(this) } }
 }
 
+fun JarOutputStream.addEntry(entry: ZipEntry) = addEntry(entry) {}
+
 inline fun JarOutputStream.addEntry(entry: ZipEntry, write: () -> Unit) {
     putNextEntry(entry)
     write()

testing/node-driver/src/main/kotlin/net/corda/testing/node/internal/TestCordappImpl.kt

@@ -54,15 +54,14 @@ data class TestCordappImpl(val scanPackage: String, override val config: Map<Str
 
         private fun findRootPaths(scanPackage: String): Set<Path> {
             return packageToRootPaths.computeIfAbsent(scanPackage) {
-                ClassGraph()
-                        .whitelistPackages(scanPackage)
-                        .pooledScan()
-                        .use { it.allResources }
+                ClassGraph().whitelistPackages(scanPackage).pooledScan().use { result ->
+                    result.allResources
                         .asSequence()
                         .map { it.classpathElementFile.toPath() }
                         .filterNot { it.toString().endsWith("-tests.jar") }
                         .map { if (it.toString().endsWith(".jar")) it else findProjectRoot(it) }
                         .toSet()
+                }
             }
         }
 

testing/test-utils/src/main/kotlin/net/corda/testing/internal/InternalSerializationTestHelpers.kt

@@ -1,20 +1,35 @@
 package net.corda.testing.internal
 
 import net.corda.client.rpc.internal.serialization.amqp.AMQPClientSerializationScheme
+import net.corda.core.internal.createInstancesOfClassesImplementing
+import net.corda.core.serialization.SerializationCustomSerializer
+import net.corda.core.serialization.SerializationWhitelist
 import net.corda.core.serialization.internal.SerializationEnvironment
 import net.corda.node.serialization.amqp.AMQPServerSerializationScheme
 import net.corda.node.serialization.kryo.KRYO_CHECKPOINT_CONTEXT
 import net.corda.node.serialization.kryo.KryoCheckpointSerializer
 import net.corda.serialization.internal.*
 import net.corda.testing.common.internal.asContextEnv
+import java.util.ServiceLoader
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.ExecutorService
 
 val inVMExecutors = ConcurrentHashMap<SerializationEnvironment, ExecutorService>()
 
 fun createTestSerializationEnv(): SerializationEnvironment {
+    return createTestSerializationEnv(null)
+}
+
+fun createTestSerializationEnv(classLoader: ClassLoader?): SerializationEnvironment {
+    val clientSerializationScheme = if (classLoader != null) {
+        val customSerializers = createInstancesOfClassesImplementing(classLoader, SerializationCustomSerializer::class.java)
+        val serializationWhitelists = ServiceLoader.load(SerializationWhitelist::class.java, classLoader).toSet()
+        AMQPClientSerializationScheme(customSerializers, serializationWhitelists)
+    } else {
+        AMQPClientSerializationScheme(emptyList())
+    }
     val factory = SerializationFactoryImpl().apply {
-        registerScheme(AMQPClientSerializationScheme(emptyList()))
+        registerScheme(clientSerializationScheme)
         registerScheme(AMQPServerSerializationScheme(emptyList()))
     }
     return SerializationEnvironment.with(