Merge pull request #7673 from corda/shams-contracts-component-group

ENT-11355: Backwards compatibility with older nodes via new attachments component group

.ci/api-current.txt

@@ -7924,11 +7924,6 @@ public final class net.corda.core.transactions.WireTransaction extends net.corda
   public final net.corda.core.transactions.LedgerTransaction toLedgerTransaction(net.corda.core.node.ServicesForResolution)
   @NotNull
   public String toString()
-  @NotNull
-  public static final net.corda.core.transactions.WireTransaction$Companion Companion
-##
-public static final class net.corda.core.transactions.WireTransaction$Companion extends java.lang.Object
-  public <init>(kotlin.jvm.internal.DefaultConstructorMarker)
 ##
 public final class net.corda.core.utilities.ByteArrays extends java.lang.Object
   @NotNull

client/jackson/src/main/kotlin/net/corda/client/jackson/internal/CordaModule.kt

@@ -95,7 +95,8 @@ import java.math.BigDecimal
 import java.security.PublicKey
 import java.security.cert.CertPath
 import java.time.Instant
-import java.util.*
+import java.util.Currency
+import java.util.UUID
 
 class CordaModule : SimpleModule("corda-core") {
     override fun setupModule(context: SetupContext) {
@@ -256,6 +257,7 @@ private data class StxJson(
 private interface WireTransactionMixin
 
 private class WireTransactionSerializer : JsonSerializer<WireTransaction>() {
+    @Suppress("INVISIBLE_MEMBER")
     override fun serialize(value: WireTransaction, gen: JsonGenerator, serializers: SerializerProvider) {
         gen.writeObject(WireTransactionJson(
                 value.digestService,
@@ -265,7 +267,7 @@ private class WireTransactionSerializer : JsonSerializer<WireTransaction>() {
                 value.outputs,
                 value.commands,
                 value.timeWindow,
-                value.attachments,
+                value.legacyAttachments.map { "$it-legacy" } + value.nonLegacyAttachments.map { it.toString() },
                 value.references,
                 value.privacySalt,
                 value.networkParametersHash
@@ -276,15 +278,18 @@ private class WireTransactionSerializer : JsonSerializer<WireTransaction>() {
 private class WireTransactionDeserializer : JsonDeserializer<WireTransaction>() {
     override fun deserialize(parser: JsonParser, ctxt: DeserializationContext): WireTransaction {
         val wrapper = parser.readValueAs<WireTransactionJson>()
+        // We're not concerned with backwards compatibility for any JSON string that was created with 4.11 and being materialised in 4.12.
+        val (legacyAttachments, newerAttachments) = wrapper.attachments.partition { it.endsWith("-legacy") }
         val componentGroups = createComponentGroups(
                 wrapper.inputs,
                 wrapper.outputs,
                 wrapper.commands,
-                wrapper.attachments,
+                newerAttachments.map(SecureHash::parse),
                 wrapper.notary,
                 wrapper.timeWindow,
                 wrapper.references,
-                wrapper.networkParametersHash
+                wrapper.networkParametersHash,
+                legacyAttachments.map { SecureHash.parse(it.removeSuffix("-legacy")) }
         )
         return WireTransaction(componentGroups, wrapper.privacySalt, wrapper.digestService ?: DigestService.sha2_256)
     }
@@ -297,10 +302,11 @@ private class WireTransactionJson(@get:JsonInclude(Include.NON_NULL) val digestS
                                   val outputs: List<TransactionState<*>>,
                                   val commands: List<Command<*>>,
                                   val timeWindow: TimeWindow?,
-                                  val attachments: List<SecureHash>,
+                                  val attachments: List<String>,
                                   val references: List<StateRef>,
                                   val privacySalt: PrivacySalt,
-                                  val networkParametersHash: SecureHash?)
+                                  val networkParametersHash: SecureHash?
+)
 
 private interface TransactionStateMixin {
     @get:JsonTypeInfo(use = JsonTypeInfo.Id.CLASS)

core-tests/build.gradle

@@ -57,6 +57,10 @@ processSmokeTestResources {
     from(configurations.corda4_11)
 }
 
+processTestResources {
+    from(configurations.corda4_11)
+}
+
 dependencies {
     testImplementation "org.junit.jupiter:junit-jupiter-api:${junit_jupiter_version}"
     testImplementation "junit:junit:$junit_version"

core-tests/src/smoke-test/kotlin/net/corda/coretests/verification/ExternalVerificationTests.kt

@@ -1,6 +1,5 @@
 package net.corda.coretests.verification
 
-import co.paralleluniverse.strands.concurrent.CountDownLatch
 import net.corda.client.rpc.CordaRPCClientConfiguration
 import net.corda.client.rpc.notUsed
 import net.corda.core.contracts.Amount
@@ -13,12 +12,18 @@ import net.corda.core.internal.toPath
 import net.corda.core.messaging.CordaRPCOps
 import net.corda.core.messaging.startFlow
 import net.corda.core.node.NodeInfo
+import net.corda.core.transactions.SignedTransaction
 import net.corda.core.utilities.OpaqueBytes
 import net.corda.core.utilities.getOrThrow
+import net.corda.coretests.verification.VerificationType.BOTH
+import net.corda.coretests.verification.VerificationType.EXTERNAL
 import net.corda.finance.DOLLARS
+import net.corda.finance.USD
+import net.corda.finance.contracts.asset.Cash
 import net.corda.finance.flows.AbstractCashFlow
 import net.corda.finance.flows.CashIssueFlow
 import net.corda.finance.flows.CashPaymentFlow
+import net.corda.finance.workflows.getCashBalance
 import net.corda.nodeapi.internal.config.User
 import net.corda.smoketesting.NodeParams
 import net.corda.smoketesting.NodeProcess
@@ -31,15 +36,16 @@ import org.assertj.core.api.Assertions.assertThatExceptionOfType
 import org.junit.AfterClass
 import org.junit.BeforeClass
 import org.junit.Test
+import rx.Observable
 import java.net.InetAddress
 import java.nio.file.Path
 import java.util.Currency
+import java.util.concurrent.CompletableFuture
 import java.util.concurrent.atomic.AtomicInteger
 import kotlin.io.path.Path
 import kotlin.io.path.copyTo
 import kotlin.io.path.div
 import kotlin.io.path.listDirectoryEntries
-import kotlin.io.path.name
 import kotlin.io.path.readText
 
 class ExternalVerificationSignedCordappsTest {
@@ -48,27 +54,30 @@ class ExternalVerificationSignedCordappsTest {
 
         private lateinit var notaries: List<NodeProcess>
         private lateinit var oldNode: NodeProcess
-        private lateinit var newNode: NodeProcess
+        private lateinit var currentNode: NodeProcess
 
         @BeforeClass
         @JvmStatic
         fun startNodes() {
-            // The 4.11 finance CorDapp jars
+            val (legacyContractsCordapp, legacyWorkflowsCordapp) = listOf("contracts", "workflows").map { smokeTestResource("corda-finance-$it-4.11.jar") }
-            val oldCordapps = listOf("contracts", "workflows").map { smokeTestResource("corda-finance-$it-4.11.jar") }
             // The current version finance CorDapp jars
-            val newCordapps = listOf("contracts", "workflows").map { smokeTestResource("corda-finance-$it.jar") }
+            val currentCordapps = listOf("contracts", "workflows").map { smokeTestResource("corda-finance-$it.jar") }
 
             notaries = factory.createNotaries(
-                    nodeParams(DUMMY_NOTARY_NAME, oldCordapps),
+                    nodeParams(DUMMY_NOTARY_NAME, cordappJars = currentCordapps, legacyContractJars = listOf(legacyContractsCordapp)),
-                    nodeParams(CordaX500Name("Notary Service 2", "Zurich", "CH"), newCordapps)
+                    nodeParams(CordaX500Name("Notary Service 2", "Zurich", "CH"), currentCordapps)
             )
             oldNode = factory.createNode(nodeParams(
                     CordaX500Name("Old", "Delhi", "IN"),
-                    oldCordapps + listOf(smokeTestResource("4.11-workflows-cordapp.jar")),
+                    listOf(legacyContractsCordapp, legacyWorkflowsCordapp, smokeTestResource("4.11-workflows-cordapp.jar")),
-                    CordaRPCClientConfiguration(minimumServerProtocolVersion = 13),
+                    clientRpcConfig = CordaRPCClientConfiguration(minimumServerProtocolVersion = 13),
                     version = "4.11"
             ))
-            newNode = factory.createNode(nodeParams(CordaX500Name("New", "York", "US"), newCordapps))
+            currentNode = factory.createNode(nodeParams(
+                    CordaX500Name("New", "York", "US"),
+                    currentCordapps,
+                    listOf(legacyContractsCordapp)
+            ))
         }
 
         @AfterClass
@@ -79,8 +88,17 @@ class ExternalVerificationSignedCordappsTest {
     }
 
     @Test(timeout=300_000)
-    fun `transaction containing 4_11 contract sent to new node`() {
+    fun `transaction containing 4_11 contract attachment only sent to current node`() {
-        assertCashIssuanceAndPayment(issuer = oldNode, recipient = newNode)
+        val (issuanceTx, paymentTx) = cashIssuanceAndPayment(issuer = oldNode, recipient = currentNode)
+        notaries[0].assertTransactionsWereVerified(EXTERNAL, paymentTx.id)
+        currentNode.assertTransactionsWereVerified(EXTERNAL, issuanceTx.id, paymentTx.id)
+    }
+
+    @Test(timeout=300_000)
+    fun `transaction containing 4_11 and 4_12 contract attachments sent to old node`() {
+        val (issuanceTx, paymentTx) = cashIssuanceAndPayment(issuer = currentNode, recipient = oldNode)
+        notaries[0].assertTransactionsWereVerified(BOTH, paymentTx.id)
+        currentNode.assertTransactionsWereVerified(BOTH, issuanceTx.id, paymentTx.id)
     }
 
     @Test(timeout=300_000)
@@ -94,12 +112,14 @@ class ExternalVerificationSignedCordappsTest {
         oldRpc.startFlow(::IssueAndChangeNotaryFlow, notaryIdentities[0], notaryIdentities[1]).returnValue.getOrThrow()
     }
 
-    private fun assertCashIssuanceAndPayment(issuer: NodeProcess, recipient: NodeProcess) {
+    private fun cashIssuanceAndPayment(issuer: NodeProcess, recipient: NodeProcess): Pair<SignedTransaction, SignedTransaction> {
         val issuerRpc = issuer.connect(superUser).proxy
         val recipientRpc = recipient.connect(superUser).proxy
         val recipientNodeInfo = recipientRpc.nodeInfo()
         val notaryIdentity = issuerRpc.notaryIdentities()[0]
 
+        val beforeAmount = recipientRpc.getCashBalance(USD)
+
         val (issuanceTx) = issuerRpc.startFlow(
                 ::CashIssueFlow,
                 10.DOLLARS,
@@ -110,6 +130,9 @@ class ExternalVerificationSignedCordappsTest {
         issuerRpc.waitForVisibility(recipientNodeInfo)
         recipientRpc.waitForVisibility(issuerRpc.nodeInfo())
 
+        val (_, update) = recipientRpc.vaultTrack(Cash.State::class.java)
+        val cashArrived = update.waitForFirst { true }
+
         val (paymentTx) = issuerRpc.startFlow(
                 ::CashPaymentFlow,
                 10.DOLLARS,
@@ -117,8 +140,10 @@ class ExternalVerificationSignedCordappsTest {
                 false,
         ).returnValue.getOrThrow()
 
-        notaries[0].assertTransactionsWereVerifiedExternally(issuanceTx.id, paymentTx.id)
+        cashArrived.getOrThrow()
-        recipient.assertTransactionsWereVerifiedExternally(issuanceTx.id, paymentTx.id)
+        assertThat(recipientRpc.getCashBalance(USD) - beforeAmount).isEqualTo(10.DOLLARS)
+
+        return Pair(issuanceTx, paymentTx)
     }
 }
 
@@ -134,18 +159,18 @@ class ExternalVerificationUnsignedCordappsTest {
         @JvmStatic
         fun startNodes() {
             // The 4.11 finance CorDapp jars
-            val oldCordapps = listOf(unsignedResourceJar("corda-finance-contracts-4.11.jar"), smokeTestResource("corda-finance-workflows-4.11.jar"))
+            val legacyCordapps = listOf(unsignedResourceJar("corda-finance-contracts-4.11.jar"), smokeTestResource("corda-finance-workflows-4.11.jar"))
             // The current version finance CorDapp jars
-            val newCordapps = listOf(unsignedResourceJar("corda-finance-contracts.jar"), smokeTestResource("corda-finance-workflows.jar"))
+            val currentCordapps = listOf(unsignedResourceJar("corda-finance-contracts.jar"), smokeTestResource("corda-finance-workflows.jar"))
 
-            notary = factory.createNotaries(nodeParams(DUMMY_NOTARY_NAME, oldCordapps))[0]
+            notary = factory.createNotaries(nodeParams(DUMMY_NOTARY_NAME, currentCordapps))[0]
             oldNode = factory.createNode(nodeParams(
                     CordaX500Name("Old", "Delhi", "IN"),
-                    oldCordapps,
+                    legacyCordapps,
-                    CordaRPCClientConfiguration(minimumServerProtocolVersion = 13),
+                    clientRpcConfig = CordaRPCClientConfiguration(minimumServerProtocolVersion = 13),
                     version = "4.11"
             ))
-            newNode = factory.createNode(nodeParams(CordaX500Name("New", "York", "US"), newCordapps))
+            newNode = factory.createNode(nodeParams(CordaX500Name("New", "York", "US"), currentCordapps))
         }
 
         @AfterClass
@@ -200,6 +225,7 @@ private fun smokeTestResource(name: String): Path = ExternalVerificationSignedCo
 private fun nodeParams(
         legalName: CordaX500Name,
         cordappJars: List<Path> = emptyList(),
+        legacyContractJars: List<Path> = emptyList(),
         clientRpcConfig: CordaRPCClientConfiguration = CordaRPCClientConfiguration.DEFAULT,
         version: String? = null
 ): NodeParams {
@@ -210,6 +236,7 @@ private fun nodeParams(
             rpcAdminPort = portCounter.andIncrement,
             users = listOf(superUser),
             cordappJars = cordappJars,
+            legacyContractJars = legacyContractJars,
             clientRpcConfig = clientRpcConfig,
             version = version
     )
@@ -220,28 +247,41 @@ private fun CordaRPCOps.waitForVisibility(other: NodeInfo) {
     if (other in snapshot) {
         updates.notUsed()
     } else {
-        val found = CountDownLatch(1)
+        updates.waitForFirst { it.node == other }.getOrThrow()
-        val subscription = updates.subscribe {
+    }
-            if (it.node == other) {
+}
-                found.countDown()
+
-            }
+private fun <T> Observable<T>.waitForFirst(predicate: (T) -> Boolean): CompletableFuture<Unit> {
+    val found = CompletableFuture<Unit>()
+    val subscription = subscribe {
+        if (predicate(it)) {
+            found.complete(Unit)
         }
-        found.await()
-        subscription.unsubscribe()
     }
+    return found.whenComplete { _, _ -> subscription.unsubscribe() }
 }
 
-private fun NodeProcess.assertTransactionsWereVerifiedExternally(vararg txIds: SecureHash) {
+private fun NodeProcess.assertTransactionsWereVerified(verificationType: VerificationType, vararg txIds: SecureHash) {
-    val verifierLogContent = externalVerifierLogs()
+    val nodeLogs = logs("node")!!
+    val externalVerifierLogs = externalVerifierLogs()
     for (txId in txIds) {
-        assertThat(verifierLogContent).contains("SignedTransaction(id=$txId) verified")
+        assertThat(nodeLogs).contains("Transaction $txId has verification type $verificationType")
+        if (verificationType != VerificationType.IN_PROCESS) {
+            assertThat(externalVerifierLogs).describedAs("External verifier was not started").isNotNull()
+            assertThat(externalVerifierLogs).contains("SignedTransaction(id=$txId) verified")
+        }
     }
 }
 
-private fun NodeProcess.externalVerifierLogs(): String {
+private fun NodeProcess.externalVerifierLogs(): String? = logs("verifier")
-    val verifierLogs = (nodeDir / "logs")
+
-            .listDirectoryEntries()
+private fun NodeProcess.logs(name: String): String? {
-            .filter { it.name == "verifier-${InetAddress.getLocalHost().hostName}.log" }
+    return (nodeDir / "logs")
-    assertThat(verifierLogs).describedAs("External verifier was not started").hasSize(1)
+            .listDirectoryEntries("$name-${InetAddress.getLocalHost().hostName}.log")
-    return verifierLogs[0].readText()
+            .singleOrNull()
+            ?.readText()
+}
+
+private enum class VerificationType {
+    IN_PROCESS, EXTERNAL, BOTH
 }

core-tests/src/test/kotlin/net/corda/coretests/transactions/CompatibleTransactionTests.kt

@@ -1,23 +1,56 @@
 package net.corda.coretests.transactions
 
-import net.corda.core.contracts.*
+import net.corda.core.contracts.Command
-import net.corda.core.contracts.ComponentGroupEnum.*
+import net.corda.core.contracts.ComponentGroupEnum
-import net.corda.core.crypto.*
+import net.corda.core.contracts.ComponentGroupEnum.ATTACHMENTS_V2_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.COMMANDS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.INPUTS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.NOTARY_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.OUTPUTS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.PARAMETERS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.SIGNERS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.TIMEWINDOW_GROUP
+import net.corda.core.contracts.PrivacySalt
+import net.corda.core.contracts.StateRef
+import net.corda.core.contracts.TimeWindow
+import net.corda.core.contracts.TransactionState
+import net.corda.core.crypto.DigestService
+import net.corda.core.crypto.MerkleTree
+import net.corda.core.crypto.PartialMerkleTree
+import net.corda.core.crypto.SecureHash
+import net.corda.core.crypto.generateKeyPair
+import net.corda.core.crypto.secureRandomBytes
 import net.corda.core.internal.accessAvailableComponentHashes
 import net.corda.core.internal.accessGroupHashes
 import net.corda.core.internal.accessGroupMerkleRoots
 import net.corda.core.internal.createComponentGroups
+import net.corda.core.internal.getRequiredGroup
 import net.corda.core.serialization.serialize
-import net.corda.core.transactions.*
+import net.corda.core.transactions.ComponentGroup
+import net.corda.core.transactions.ComponentVisibilityException
+import net.corda.core.transactions.FilteredComponentGroup
+import net.corda.core.transactions.FilteredTransaction
+import net.corda.core.transactions.FilteredTransactionVerificationException
+import net.corda.core.transactions.NetworkParametersHash
+import net.corda.core.transactions.WireTransaction
 import net.corda.core.utilities.OpaqueBytes
 import net.corda.testing.contracts.DummyContract
 import net.corda.testing.contracts.DummyState
-import net.corda.testing.core.*
+import net.corda.testing.core.BOB_NAME
+import net.corda.testing.core.DUMMY_NOTARY_NAME
+import net.corda.testing.core.SerializationEnvironmentRule
+import net.corda.testing.core.TestIdentity
+import net.corda.testing.core.dummyCommand
 import org.junit.Rule
 import org.junit.Test
 import java.time.Instant
 import java.util.function.Predicate
-import kotlin.test.*
+import kotlin.test.assertEquals
+import kotlin.test.assertFails
+import kotlin.test.assertFailsWith
+import kotlin.test.assertNotEquals
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
 
 class CompatibleTransactionTests {
     private companion object {
@@ -47,7 +80,7 @@ class CompatibleTransactionTests {
     private val inputGroup by lazy { ComponentGroup(INPUTS_GROUP.ordinal, inputs.map { it.serialize() }) }
     private val outputGroup by lazy { ComponentGroup(OUTPUTS_GROUP.ordinal, outputs.map { it.serialize() }) }
     private val commandGroup by lazy { ComponentGroup(COMMANDS_GROUP.ordinal, commands.map { it.value.serialize() }) }
-    private val attachmentGroup by lazy { ComponentGroup(ATTACHMENTS_GROUP.ordinal, attachments.map { it.serialize() }) } // The list is empty.
+    private val attachmentGroup by lazy { ComponentGroup(ATTACHMENTS_V2_GROUP.ordinal, attachments.map { it.serialize() }) } // The list is empty.
     private val notaryGroup by lazy { ComponentGroup(NOTARY_GROUP.ordinal, listOf(notary.serialize())) }
     private val timeWindowGroup by lazy { ComponentGroup(TIMEWINDOW_GROUP.ordinal, listOf(timeWindow.serialize())) }
     private val signersGroup by lazy { ComponentGroup(SIGNERS_GROUP.ordinal, commands.map { it.signers.serialize() }) }
@@ -96,7 +129,7 @@ class CompatibleTransactionTests {
 
         // Ordering inside a component group matters.
         val inputsShuffled = listOf(stateRef2, stateRef1, stateRef3)
-        val inputShuffledGroup = ComponentGroup(INPUTS_GROUP.ordinal, inputsShuffled.map { it -> it.serialize() })
+        val inputShuffledGroup = ComponentGroup(INPUTS_GROUP.ordinal, inputsShuffled.map { it.serialize() })
         val componentGroupsB = listOf(
                 inputShuffledGroup,
                 outputGroup,
@@ -114,8 +147,8 @@ class CompatibleTransactionTests {
         // But outputs group Merkle leaf (and the rest) remained the same.
         assertEquals(wireTransactionA.accessGroupMerkleRoots()[OUTPUTS_GROUP.ordinal], wireTransaction1ShuffledInputs.accessGroupMerkleRoots()[OUTPUTS_GROUP.ordinal])
         assertEquals(wireTransactionA.accessGroupMerkleRoots()[NOTARY_GROUP.ordinal], wireTransaction1ShuffledInputs.accessGroupMerkleRoots()[NOTARY_GROUP.ordinal])
-        assertNull(wireTransactionA.accessGroupMerkleRoots()[ATTACHMENTS_GROUP.ordinal])
+        assertNull(wireTransactionA.accessGroupMerkleRoots()[ATTACHMENTS_V2_GROUP.ordinal])
-        assertNull(wireTransaction1ShuffledInputs.accessGroupMerkleRoots()[ATTACHMENTS_GROUP.ordinal])
+        assertNull(wireTransaction1ShuffledInputs.accessGroupMerkleRoots()[ATTACHMENTS_V2_GROUP.ordinal])
 
         // Group leaves (components) ordering does not affect the id. In this case, we added outputs group before inputs.
         val shuffledComponentGroupsA = listOf(
@@ -140,7 +173,7 @@ class CompatibleTransactionTests {
                 inputGroup,
                 outputGroup,
                 commandGroup,
-                ComponentGroup(ATTACHMENTS_GROUP.ordinal, inputGroup.components),
+                ComponentGroup(ATTACHMENTS_V2_GROUP.ordinal, inputGroup.components),
                 notaryGroup,
                 timeWindowGroup,
                 signersGroup
@@ -201,23 +234,16 @@ class CompatibleTransactionTests {
     @Test(timeout=300_000)
 	fun `FilteredTransaction constructors and compatibility`() {
         // Filter out all of the components.
-        val ftxNothing = wireTransactionA.buildFilteredTransaction(Predicate { false }) // Nothing filtered.
+        val ftxNothing = wireTransactionA.buildFilteredTransaction { false } // Nothing filtered.
         // Although nothing filtered, we still receive the group hashes for the top level Merkle tree.
         // Note that attachments are not sent, but group hashes include the allOnesHash flag for the attachment group hash; that's why we expect +1 group hashes.
         assertEquals(wireTransactionA.componentGroups.size + 1, ftxNothing.groupHashes.size)
         ftxNothing.verify()
 
         // Include all of the components.
-        val ftxAll = wireTransactionA.buildFilteredTransaction(Predicate { true }) // All filtered.
+        val ftxAll = wireTransactionA.buildFilteredTransaction { true } // All filtered.
         ftxAll.verify()
-        ftxAll.checkAllComponentsVisible(INPUTS_GROUP)
+        ComponentGroupEnum.entries.forEach(ftxAll::checkAllComponentsVisible)
-        ftxAll.checkAllComponentsVisible(OUTPUTS_GROUP)
-        ftxAll.checkAllComponentsVisible(COMMANDS_GROUP)
-        ftxAll.checkAllComponentsVisible(ATTACHMENTS_GROUP)
-        ftxAll.checkAllComponentsVisible(NOTARY_GROUP)
-        ftxAll.checkAllComponentsVisible(TIMEWINDOW_GROUP)
-        ftxAll.checkAllComponentsVisible(SIGNERS_GROUP)
-        ftxAll.checkAllComponentsVisible(PARAMETERS_GROUP)
 
         // Filter inputs only.
         fun filtering(elem: Any): Boolean {
@@ -232,9 +258,9 @@ class CompatibleTransactionTests {
         ftxInputs.checkAllComponentsVisible(INPUTS_GROUP)
 
         assertEquals(1, ftxInputs.filteredComponentGroups.size) // We only add component groups that are not empty, thus in this case: the inputs only.
-        assertEquals(3, ftxInputs.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.components.size) // All 3 inputs are present.
+        assertEquals(3, ftxInputs.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).components.size) // All 3 inputs are present.
-        assertEquals(3, ftxInputs.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.nonces.size) // And their corresponding nonces.
+        assertEquals(3, ftxInputs.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).nonces.size) // And their corresponding nonces.
-        assertNotNull(ftxInputs.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.partialMerkleTree) // And the Merkle tree.
+        assertNotNull(ftxInputs.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).partialMerkleTree) // And the Merkle tree.
 
         // Filter one input only.
         fun filteringOneInput(elem: Any) = elem == inputs[0]
@@ -244,9 +270,9 @@ class CompatibleTransactionTests {
         assertFailsWith<ComponentVisibilityException> { ftxOneInput.checkAllComponentsVisible(INPUTS_GROUP) }
 
         assertEquals(1, ftxOneInput.filteredComponentGroups.size) // We only add component groups that are not empty, thus in this case: the inputs only.
-        assertEquals(1, ftxOneInput.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.components.size) // 1 input is present.
+        assertEquals(1, ftxOneInput.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).components.size) // 1 input is present.
-        assertEquals(1, ftxOneInput.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.nonces.size) // And its corresponding nonce.
+        assertEquals(1, ftxOneInput.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).nonces.size) // And its corresponding nonce.
-        assertNotNull(ftxOneInput.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.partialMerkleTree) // And the Merkle tree.
+        assertNotNull(ftxOneInput.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).partialMerkleTree) // And the Merkle tree.
 
         // The old client (receiving more component types than expected) is still compatible.
         val componentGroupsCompatibleA = listOf(
@@ -265,14 +291,14 @@ class CompatibleTransactionTests {
         assertEquals(wireTransactionCompatibleA.id, ftxCompatible.id)
 
         assertEquals(1, ftxCompatible.filteredComponentGroups.size)
-        assertEquals(3, ftxCompatible.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.components.size)
+        assertEquals(3, ftxCompatible.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).components.size)
-        assertEquals(3, ftxCompatible.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.nonces.size)
+        assertEquals(3, ftxCompatible.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).nonces.size)
-        assertNotNull(ftxCompatible.filteredComponentGroups.firstOrNull { it.groupIndex == INPUTS_GROUP.ordinal }!!.partialMerkleTree)
+        assertNotNull(ftxCompatible.filteredComponentGroups.getRequiredGroup(INPUTS_GROUP).partialMerkleTree)
         assertNull(wireTransactionCompatibleA.networkParametersHash)
         assertNull(ftxCompatible.networkParametersHash)
 
         // Now, let's allow everything, including the new component type that we cannot process.
-        val ftxCompatibleAll = wireTransactionCompatibleA.buildFilteredTransaction(Predicate { true }) // All filtered, including the unknown component.
+        val ftxCompatibleAll = wireTransactionCompatibleA.buildFilteredTransaction { true } // All filtered, including the unknown component.
         ftxCompatibleAll.verify()
         assertEquals(wireTransactionCompatibleA.id, ftxCompatibleAll.id)
 
@@ -292,7 +318,7 @@ class CompatibleTransactionTests {
         ftxCompatibleNoInputs.verify()
         assertFailsWith<ComponentVisibilityException> { ftxCompatibleNoInputs.checkAllComponentsVisible(INPUTS_GROUP) }
         assertEquals(wireTransactionCompatibleA.componentGroups.size - 1, ftxCompatibleNoInputs.filteredComponentGroups.size)
-        assertEquals(wireTransactionCompatibleA.componentGroups.map { it.groupIndex }.max(), ftxCompatibleNoInputs.groupHashes.size - 1)
+        assertEquals(wireTransactionCompatibleA.componentGroups.maxOfOrNull { it.groupIndex }, ftxCompatibleNoInputs.groupHashes.size - 1)
     }
 
     @Test(timeout=300_000)
@@ -451,7 +477,7 @@ class CompatibleTransactionTests {
         val key2CommandsFtx = wtx.buildFilteredTransaction(Predicate(::filterKEY2Commands))
 
         // val commandDataComponents = key1CommandsFtx.filteredComponentGroups[0].components
-        val commandDataHashes = wtx.accessAvailableComponentHashes()[ComponentGroupEnum.COMMANDS_GROUP.ordinal]!!
+        val commandDataHashes = wtx.accessAvailableComponentHashes()[COMMANDS_GROUP.ordinal]!!
         val noLastCommandDataPMT = PartialMerkleTree.build(
                 MerkleTree.getMerkleTree(commandDataHashes, wtx.digestService),
                 commandDataHashes.subList(0, 1)
@@ -466,7 +492,7 @@ class CompatibleTransactionTests {
         )
 
         val signerComponents = key1CommandsFtx.filteredComponentGroups[1].components
-        val signerHashes = wtx.accessAvailableComponentHashes()[ComponentGroupEnum.SIGNERS_GROUP.ordinal]!!
+        val signerHashes = wtx.accessAvailableComponentHashes()[SIGNERS_GROUP.ordinal]!!
         val noLastSignerPMT = PartialMerkleTree.build(
                 MerkleTree.getMerkleTree(signerHashes, wtx.digestService),
                 signerHashes.subList(0, 2)
@@ -527,7 +553,7 @@ class CompatibleTransactionTests {
         // Modify last signer (we have a pointer from commandData).
         // Update partial Merkle tree for signers.
         val alterSignerComponents = signerComponents.subList(0, 2) + signerComponents[1] // Third one is removed and the 2nd command is added twice.
-        val alterSignersHashes = wtx.accessAvailableComponentHashes()[ComponentGroupEnum.SIGNERS_GROUP.ordinal]!!.subList(0, 2) + wtx.digestService.componentHash(key1CommandsFtx.filteredComponentGroups[1].nonces[2], alterSignerComponents[2])
+        val alterSignersHashes = wtx.accessAvailableComponentHashes()[SIGNERS_GROUP.ordinal]!!.subList(0, 2) + wtx.digestService.componentHash(key1CommandsFtx.filteredComponentGroups[1].nonces[2], alterSignerComponents[2])
         val alterMTree = MerkleTree.getMerkleTree(alterSignersHashes, wtx.digestService)
         val alterSignerPMTK = PartialMerkleTree.build(
                 alterMTree,
@@ -561,7 +587,7 @@ class CompatibleTransactionTests {
 	fun `parameters hash visibility`() {
         fun paramsFilter(elem: Any): Boolean = elem is NetworkParametersHash && elem.hash == paramsHash
         fun attachmentFilter(elem: Any): Boolean = elem is SecureHash && elem == paramsHash
-        val attachments = ComponentGroup(ATTACHMENTS_GROUP.ordinal, listOf(paramsHash.serialize())) // Same hash as network parameters
+        val attachments = ComponentGroup(ATTACHMENTS_V2_GROUP.ordinal, listOf(paramsHash.serialize())) // Same hash as network parameters
         val componentGroups = listOf(
                 inputGroup,
                 outputGroup,
@@ -577,12 +603,12 @@ class CompatibleTransactionTests {
         ftx1.verify()
         assertEquals(wtx.id, ftx1.id)
         ftx1.checkAllComponentsVisible(PARAMETERS_GROUP)
-        assertFailsWith<ComponentVisibilityException> { ftx1.checkAllComponentsVisible(ATTACHMENTS_GROUP) }
+        assertFailsWith<ComponentVisibilityException> { ftx1.checkAllComponentsVisible(ATTACHMENTS_V2_GROUP) }
         // Filter only attachment.
         val ftx2 = wtx.buildFilteredTransaction(Predicate(::attachmentFilter))
         ftx2.verify()
         assertEquals(wtx.id, ftx2.id)
-        ftx2.checkAllComponentsVisible(ATTACHMENTS_GROUP)
+        ftx2.checkAllComponentsVisible(ATTACHMENTS_V2_GROUP)
         assertFailsWith<ComponentVisibilityException> { ftx2.checkAllComponentsVisible(PARAMETERS_GROUP) }
     }
 }

core-tests/src/test/kotlin/net/corda/coretests/transactions/TransactionBuilderMockNetworkTest.kt

@@ -0,0 +1,166 @@
+package net.corda.coretests.transactions
+
+import net.corda.core.contracts.SignatureAttachmentConstraint
+import net.corda.core.contracts.TransactionState
+import net.corda.core.internal.PlatformVersionSwitches.MIGRATE_ATTACHMENT_TO_SIGNATURE_CONSTRAINTS
+import net.corda.core.internal.RPC_UPLOADER
+import net.corda.core.internal.copyToDirectory
+import net.corda.core.internal.hash
+import net.corda.core.internal.toPath
+import net.corda.core.transactions.TransactionBuilder
+import net.corda.coretesting.internal.useZipFile
+import net.corda.finance.DOLLARS
+import net.corda.finance.contracts.asset.Cash
+import net.corda.finance.issuedBy
+import net.corda.testing.common.internal.testNetworkParameters
+import net.corda.testing.contracts.DummyContract
+import net.corda.testing.contracts.DummyState
+import net.corda.testing.core.ALICE_NAME
+import net.corda.testing.core.DummyCommandData
+import net.corda.testing.core.internal.JarSignatureTestUtils.generateKey
+import net.corda.testing.core.internal.JarSignatureTestUtils.signJar
+import net.corda.testing.core.internal.JarSignatureTestUtils.unsignJar
+import net.corda.testing.core.singleIdentity
+import net.corda.testing.node.internal.FINANCE_CONTRACTS_CORDAPP
+import net.corda.testing.node.internal.InternalMockNetwork
+import net.corda.testing.node.internal.MockNodeArgs
+import net.corda.testing.node.internal.cordappWithPackages
+import org.assertj.core.api.Assertions.assertThat
+import org.assertj.core.api.Assertions.assertThatIllegalArgumentException
+import org.junit.After
+import org.junit.Ignore
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.TemporaryFolder
+import java.nio.file.Path
+import kotlin.io.path.absolutePathString
+import kotlin.io.path.copyTo
+import kotlin.io.path.createDirectories
+import kotlin.io.path.deleteExisting
+import kotlin.io.path.div
+import kotlin.io.path.inputStream
+import kotlin.io.path.listDirectoryEntries
+
+@Suppress("INVISIBLE_MEMBER")
+class TransactionBuilderMockNetworkTest {
+    companion object {
+        val legacyFinanceContractsJar = this::class.java.getResource("/corda-finance-contracts-4.11.jar")!!.toPath()
+    }
+
+    @Rule
+    @JvmField
+    val tempFolder = TemporaryFolder()
+
+    private val mockNetwork = InternalMockNetwork(
+            cordappsForAllNodes = setOf(
+                    FINANCE_CONTRACTS_CORDAPP,
+                    cordappWithPackages("net.corda.testing.contracts").signed()
+            ),
+            initialNetworkParameters = testNetworkParameters(minimumPlatformVersion = MIGRATE_ATTACHMENT_TO_SIGNATURE_CONSTRAINTS)
+    )
+
+    @After
+    fun close() {
+        mockNetwork.close()
+    }
+
+    @Test(timeout=300_000)
+    fun `automatic signature constraint`() {
+        val services = mockNetwork.notaryNodes[0].services
+
+        val attachment = services.attachments.openAttachment(services.attachments.getLatestContractAttachments(DummyContract.PROGRAM_ID)[0])
+        val attachmentSigner = attachment!!.signerKeys.single()
+
+        val expectedConstraint = SignatureAttachmentConstraint(attachmentSigner)
+        assertThat(expectedConstraint.isSatisfiedBy(attachment)).isTrue()
+
+        val outputState = TransactionState(data = DummyState(), contract = DummyContract.PROGRAM_ID, notary = mockNetwork.defaultNotaryIdentity)
+        val builder = TransactionBuilder()
+                .addOutputState(outputState)
+                .addCommand(DummyCommandData, mockNetwork.defaultNotaryIdentity.owningKey)
+        val wtx = builder.toWireTransaction(services)
+
+        assertThat(wtx.outputs).containsOnly(outputState.copy(constraint = expectedConstraint))
+    }
+
+    @Test(timeout=300_000)
+    fun `contract overlap in explicit attachments`() {
+        val duplicateJar = tempFolder.newFile("duplicate.jar").toPath()
+        FINANCE_CONTRACTS_CORDAPP.jarFile.copyTo(duplicateJar, overwrite = true)
+        duplicateJar.unsignJar()  // Change its hash
+
+        val node = mockNetwork.createNode()
+        val duplicateId = duplicateJar.inputStream().use {
+            node.services.attachments.privilegedImportAttachment(it, RPC_UPLOADER, null)
+        }
+        assertThat(FINANCE_CONTRACTS_CORDAPP.jarFile.hash).isNotEqualTo(duplicateId)
+
+        val builder = TransactionBuilder()
+        builder.addAttachment(FINANCE_CONTRACTS_CORDAPP.jarFile.hash)
+        builder.addAttachment(duplicateId)
+        val identity = node.info.singleIdentity()
+        Cash().generateIssue(builder, 10.DOLLARS.issuedBy(identity.ref(0x00)), identity, mockNetwork.defaultNotaryIdentity)
+        assertThatIllegalArgumentException()
+                .isThrownBy { builder.toWireTransaction(node.services) }
+                .withMessageContaining("Multiple attachments specified for the same contract")
+    }
+
+    @Test(timeout=300_000)
+    fun `populates legacy attachment group if legacy contract CorDapp is present`() {
+        val node = mockNetwork.createNode {
+            it.copyToLegacyContracts(legacyFinanceContractsJar)
+            InternalMockNetwork.MockNode(it)
+        }
+        val builder = TransactionBuilder()
+        val identity = node.info.singleIdentity()
+        Cash().generateIssue(builder, 10.DOLLARS.issuedBy(identity.ref(0x00)), identity, mockNetwork.defaultNotaryIdentity)
+        val stx = node.services.signInitialTransaction(builder)
+        assertThat(stx.tx.nonLegacyAttachments).contains(FINANCE_CONTRACTS_CORDAPP.jarFile.hash)
+        assertThat(stx.tx.legacyAttachments).contains(legacyFinanceContractsJar.hash)
+        stx.verify(node.services)
+    }
+
+    @Test(timeout=300_000)
+    @Ignore // https://r3-cev.atlassian.net/browse/ENT-11445
+    fun `adds legacy CorDapp dependencies`() {
+        val cordapp1 = tempFolder.newFile("cordapp1.jar").toPath()
+        val cordapp2 = tempFolder.newFile("cordapp2.jar").toPath()
+        // Split the contracts CorDapp into two
+        legacyFinanceContractsJar.copyTo(cordapp1, overwrite = true)
+        cordapp1.useZipFile { zipFs1 ->
+            cordapp2.useZipFile { zipFs2 ->
+                val destinationDir = zipFs2.getPath("net/corda/finance/contracts/asset").createDirectories()
+                zipFs1.getPath("net/corda/finance/contracts/asset")
+                        .listDirectoryEntries("OnLedgerAsset*")
+                        .forEach {
+                            it.copyToDirectory(destinationDir)
+                            it.deleteExisting()
+                        }
+            }
+        }
+        reSignJar(cordapp1)
+
+        val node = mockNetwork.createNode {
+            it.copyToLegacyContracts(cordapp1, cordapp2)
+            InternalMockNetwork.MockNode(it)
+        }
+        val builder = TransactionBuilder()
+        val identity = node.info.singleIdentity()
+        Cash().generateIssue(builder, 10.DOLLARS.issuedBy(identity.ref(0x00)), identity, mockNetwork.defaultNotaryIdentity)
+        val stx = node.services.signInitialTransaction(builder)
+        assertThat(stx.tx.nonLegacyAttachments).contains(FINANCE_CONTRACTS_CORDAPP.jarFile.hash)
+        assertThat(stx.tx.legacyAttachments).contains(cordapp1.hash, cordapp2.hash)
+        stx.verify(node.services)
+    }
+
+    private fun reSignJar(jar: Path) {
+        jar.unsignJar()
+        tempFolder.root.toPath().generateKey("testAlias", "testPassword", ALICE_NAME.toString())
+        tempFolder.root.toPath().signJar(jar.absolutePathString(), "testAlias", "testPassword")
+    }
+
+    private fun MockNodeArgs.copyToLegacyContracts(vararg jars: Path) {
+        val legacyContractsDir = (config.baseDirectory / "legacy-contracts").createDirectories()
+        jars.forEach { it.copyToDirectory(legacyContractsDir) }
+    }
+}

core-tests/src/test/kotlin/net/corda/coretests/transactions/TransactionBuilderTest.kt

@@ -3,7 +3,6 @@ package net.corda.coretests.transactions
 import net.corda.core.contracts.Command
 import net.corda.core.contracts.HashAttachmentConstraint
 import net.corda.core.contracts.PrivacySalt
-import net.corda.core.contracts.SignatureAttachmentConstraint
 import net.corda.core.contracts.StateAndRef
 import net.corda.core.contracts.StateRef
 import net.corda.core.contracts.TimeWindow
@@ -16,7 +15,6 @@ import net.corda.core.internal.PLATFORM_VERSION
 import net.corda.core.internal.RPC_UPLOADER
 import net.corda.core.internal.digestService
 import net.corda.core.node.ZoneVersionTooLowException
-import net.corda.core.serialization.internal._driverSerializationEnv
 import net.corda.core.transactions.TransactionBuilder
 import net.corda.testing.common.internal.testNetworkParameters
 import net.corda.testing.contracts.DummyContract
@@ -26,15 +24,12 @@ import net.corda.testing.core.DUMMY_NOTARY_NAME
 import net.corda.testing.core.DummyCommandData
 import net.corda.testing.core.SerializationEnvironmentRule
 import net.corda.testing.core.TestIdentity
-import net.corda.testing.node.MockNetwork
-import net.corda.testing.node.MockNetworkParameters
 import net.corda.testing.node.MockServices
 import net.corda.testing.node.internal.cordappWithPackages
 import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.Assertions.assertThatExceptionOfType
 import org.assertj.core.api.Assertions.assertThatIllegalArgumentException
 import org.assertj.core.api.Assertions.assertThatThrownBy
-import org.junit.Assert.assertTrue
 import org.junit.Ignore
 import org.junit.Rule
 import org.junit.Test
@@ -56,6 +51,7 @@ class TransactionBuilderTest {
     private val contractAttachmentId = services.attachments.getLatestContractAttachments(DummyContract.PROGRAM_ID)[0]
 
     @Test(timeout=300_000)
+    @Suppress("INVISIBLE_MEMBER")
 	fun `bare minimum issuance tx`() {
         val outputState = TransactionState(
                 data = DummyState(),
@@ -70,6 +66,9 @@ class TransactionBuilderTest {
         assertThat(wtx.outputs).containsOnly(outputState)
         assertThat(wtx.commands).containsOnly(Command(DummyCommandData, notary.owningKey))
         assertThat(wtx.networkParametersHash).isEqualTo(services.networkParametersService.currentHash)
+        // From 4.12 attachments are added to the new component group by default
+        assertThat(wtx.nonLegacyAttachments).isNotEmpty
+        assertThat(wtx.legacyAttachments).isEmpty()
     }
 
     @Test(timeout=300_000)
@@ -105,41 +104,6 @@ class TransactionBuilderTest {
         }
     }
 
-    @Test(timeout=300_000)
-	fun `automatic signature constraint`() {
-        // We need to use a MockNetwork so that we can create a signed attachment. However, SerializationEnvironmentRule and MockNetwork
-        // don't work well together, so we temporarily clear out the driverSerializationEnv for this test.
-        val driverSerializationEnv = _driverSerializationEnv.get()
-        _driverSerializationEnv.set(null)
-        val mockNetwork = MockNetwork(
-                MockNetworkParameters(
-                        networkParameters = testNetworkParameters(minimumPlatformVersion = PLATFORM_VERSION),
-                        cordappsForAllNodes = listOf(cordappWithPackages("net.corda.testing.contracts").signed())
-                )
-        )
-
-        try {
-            val services = mockNetwork.notaryNodes[0].services
-
-            val attachment = services.attachments.openAttachment(services.attachments.getLatestContractAttachments(DummyContract.PROGRAM_ID)[0])
-            val attachmentSigner = attachment!!.signerKeys.single()
-
-            val expectedConstraint = SignatureAttachmentConstraint(attachmentSigner)
-            assertTrue(expectedConstraint.isSatisfiedBy(attachment))
-
-            val outputState = TransactionState(data = DummyState(), contract = DummyContract.PROGRAM_ID, notary = notary)
-            val builder = TransactionBuilder()
-                    .addOutputState(outputState)
-                    .addCommand(DummyCommandData, notary.owningKey)
-            val wtx = builder.toWireTransaction(services)
-
-            assertThat(wtx.outputs).containsOnly(outputState.copy(constraint = expectedConstraint))
-        } finally {
-            mockNetwork.stopNodes()
-            _driverSerializationEnv.set(driverSerializationEnv)
-        }
-    }
-
     @Test(timeout=300_000)
     fun `list accessors are mutable copies`() {
         val inputState1 = TransactionState(DummyState(), DummyContract.PROGRAM_ID, notary)

core/src/main/kotlin/net/corda/core/contracts/ComponentGroupEnum.kt

@@ -8,10 +8,11 @@ enum class ComponentGroupEnum {
     INPUTS_GROUP, // ordinal = 0.
     OUTPUTS_GROUP, // ordinal = 1.
     COMMANDS_GROUP, // ordinal = 2.
-    ATTACHMENTS_GROUP, // ordinal = 3.
+    ATTACHMENTS_GROUP, // ordinal = 3. This is for legacy attachments. It's not been renamed for backwards compatibility.
     NOTARY_GROUP, // ordinal = 4.
     TIMEWINDOW_GROUP, // ordinal = 5.
     SIGNERS_GROUP, // ordinal = 6.
     REFERENCES_GROUP, // ordinal = 7.
-    PARAMETERS_GROUP // ordinal = 8.
+    PARAMETERS_GROUP, // ordinal = 8.
+    ATTACHMENTS_V2_GROUP // ordinal = 9. From 4.12+ this group is used for attachments.
 }

core/src/main/kotlin/net/corda/core/flows/CollectSignaturesFlow.kt

@@ -67,12 +67,12 @@ import java.security.PublicKey
 class CollectSignaturesFlow @JvmOverloads constructor(val partiallySignedTx: SignedTransaction,
                                                       val sessionsToCollectFrom: Collection<FlowSession>,
                                                       val myOptionalKeys: Iterable<PublicKey>?,
-                                                      override val progressTracker: ProgressTracker = CollectSignaturesFlow.tracker()) : FlowLogic<SignedTransaction>() {
+                                                      override val progressTracker: ProgressTracker = tracker()) : FlowLogic<SignedTransaction>() {
     @JvmOverloads
     constructor(
             partiallySignedTx: SignedTransaction,
             sessionsToCollectFrom: Collection<FlowSession>,
-            progressTracker: ProgressTracker = CollectSignaturesFlow.tracker()
+            progressTracker: ProgressTracker = tracker()
     ) : this(partiallySignedTx, sessionsToCollectFrom, null, progressTracker)
 
     companion object {
@@ -100,6 +100,7 @@ class CollectSignaturesFlow @JvmOverloads constructor(val partiallySignedTx: Sig
 
         // The signatures must be valid and the transaction must be valid.
         partiallySignedTx.verifySignaturesExcept(notSigned)
+        // TODO Should this be calling SignedTransaction.verify directly? https://r3-cev.atlassian.net/browse/ENT-11458
         partiallySignedTx.tx.toLedgerTransaction(serviceHub).verify()
 
         // Determine who still needs to sign.
@@ -235,7 +236,7 @@ class CollectSignatureFlow(val partiallySignedTx: SignedTransaction, val session
  * - Call the flow via [FlowLogic.subFlow]
  * - The flow returns the transaction signed with the additional signature.
  *
- * Example - checking and signing a transaction involving a [net.corda.core.contracts.DummyContract], see
+ * Example - checking and signing a transaction involving a `DummyContract`, see
  * CollectSignaturesFlowTests.kt for further examples:
  *
  *     class Responder(val otherPartySession: FlowSession): FlowLogic<SignedTransaction>() {
@@ -259,7 +260,7 @@ class CollectSignatureFlow(val partiallySignedTx: SignedTransaction, val session
  * @param otherSideSession The session which is providing you a transaction to sign.
  */
 abstract class SignTransactionFlow @JvmOverloads constructor(val otherSideSession: FlowSession,
-                                                             override val progressTracker: ProgressTracker = SignTransactionFlow.tracker()) : FlowLogic<SignedTransaction>() {
+                                                             override val progressTracker: ProgressTracker = tracker()) : FlowLogic<SignedTransaction>() {
 
     companion object {
         object RECEIVING : ProgressTracker.Step("Receiving transaction proposal for signing.")
@@ -287,6 +288,7 @@ abstract class SignTransactionFlow @JvmOverloads constructor(val otherSideSessio
         checkMySignaturesRequired(stx, signingKeys)
         // Check the signatures which have already been provided. Usually the Initiators and possibly an Oracle's.
         checkSignatures(stx)
+        // TODO Should this be calling SignedTransaction.verify directly? https://r3-cev.atlassian.net/browse/ENT-11458
         stx.tx.toLedgerTransaction(serviceHub).verify()
         // Perform some custom verification over the transaction.
         try {

core/src/main/kotlin/net/corda/core/flows/FinalityFlow.kt

@@ -11,12 +11,14 @@ import net.corda.core.internal.PlatformVersionSwitches
 import net.corda.core.internal.ServiceHubCoreInternal
 import net.corda.core.internal.pushToLoggingContext
 import net.corda.core.internal.telemetry.telemetryServiceInternal
+import net.corda.core.internal.verification.toVerifyingServiceHub
 import net.corda.core.internal.warnOnce
 import net.corda.core.node.StatesToRecord
 import net.corda.core.node.StatesToRecord.ONLY_RELEVANT
 import net.corda.core.serialization.DeprecatedConstructorForDeserialization
 import net.corda.core.transactions.LedgerTransaction
 import net.corda.core.transactions.SignedTransaction
+import net.corda.core.transactions.WireTransaction
 import net.corda.core.utilities.ProgressTracker
 import net.corda.core.utilities.Try
 import net.corda.core.utilities.debug
@@ -170,6 +172,7 @@ class FinalityFlow private constructor(val transaction: SignedTransaction,
     @Suppress("ComplexMethod", "NestedBlockDepth")
     @Throws(NotaryException::class)
     override fun call(): SignedTransaction {
+        require(transaction.coreTransaction is WireTransaction)  // Sanity check
         if (!newApi) {
             logger.warnOnce("The current usage of FinalityFlow is unsafe. Please consider upgrading your CorDapp to use " +
                     "FinalityFlow with FlowSessions. (${serviceHub.getAppContext().cordapp.info})")
@@ -447,9 +450,12 @@ class FinalityFlow private constructor(val transaction: SignedTransaction,
         // The notary signature(s) are allowed to be missing but no others.
         if (notary != null) transaction.verifySignaturesExcept(notary.owningKey) else transaction.verifyRequiredSignatures()
         // TODO= [CORDA-3267] Remove duplicate signature verification
-        val ltx = transaction.toLedgerTransaction(serviceHub, false)
+        val ltx = transaction.verifyInternal(serviceHub.toVerifyingServiceHub(), checkSufficientSignatures = false) as LedgerTransaction?
-        ltx.verify()
+        // verifyInternal returns null if the transaction was verified externally, which *could* happen on a very odd scenerio of a 4.11
-        return ltx
+        // node creating the transaction but a 4.12 kicking off finality. In that case, we still want a LedgerTransaction object for
+        // recording to the vault, etc. Note that calling verify() on this will fail as it doesn't have the necessary non-legacy attachments
+        // for verification by the node.
+        return ltx ?: transaction.toLedgerTransaction(serviceHub, checkSufficientSignatures = false)
     }
 }
 

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

@@ -1,28 +0,0 @@
-package net.corda.core.internal
-
-import net.corda.core.contracts.Attachment
-import net.corda.core.contracts.ContractAttachment
-
-interface InternalAttachment : Attachment {
-    /**
-     * The version of the Kotlin metadata, if this attachment has one. See `kotlinx.metadata.jvm.JvmMetadataVersion` for more information on
-     * how this maps to the Kotlin language version.
-     */
-    val kotlinMetadataVersion: String?
-}
-
-/**
- * Because [ContractAttachment] is public API, we can't make it implement [InternalAttachment] without also leaking it out.
- *
- * @see InternalAttachment.kotlinMetadataVersion
- */
-val Attachment.kotlinMetadataVersion: String? get() {
-    var attachment = this
-    while (true) {
-        when (attachment) {
-            is InternalAttachment -> return attachment.kotlinMetadataVersion
-            is ContractAttachment -> attachment = attachment.attachment
-            else -> return null
-        }
-    }
-}

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

@@ -79,7 +79,14 @@ import kotlin.math.roundToLong
 import kotlin.reflect.KClass
 import kotlin.reflect.full.createInstance
 
-val Throwable.rootCause: Throwable get() = cause?.rootCause ?: this
+val Throwable.rootCause: Throwable
+    get() {
+        var root = this
+        while (true) {
+            root = root.cause ?: return root
+        }
+    }
+
 val Throwable.rootMessage: String? get() {
     var message = this.message
     var throwable = cause
@@ -231,8 +238,6 @@ inline fun elapsedTime(block: () -> Unit): Duration {
 
 fun <T> Logger.logElapsedTime(label: String, body: () -> T): T = logElapsedTime(label, this, body)
 
-// TODO: Add inline back when a new Kotlin version is released and check if the java.lang.VerifyError
-// returns in the IRSSimulationTest. If not, commit the inline back.
 fun <T> logElapsedTime(label: String, logger: Logger? = null, body: () -> T): T {
     // Use nanoTime as it's monotonic.
     val now = System.nanoTime()
@@ -639,16 +644,10 @@ val Logger.level: Level
         else -> throw IllegalStateException("Unknown logging level")
     }
 
-const val JAVA_1_2_CLASS_FILE_FORMAT_MAJOR_VERSION = 46
+const val JAVA_1_2_CLASS_FILE_MAJOR_VERSION = 46
-const val JAVA_17_CLASS_FILE_FORMAT_MAJOR_VERSION = 61
+const val JAVA_8_CLASS_FILE_MAJOR_VERSION = 52
+const val JAVA_17_CLASS_FILE_MAJOR_VERSION = 61
 
-/**
+fun String.capitalize(): String = replaceFirstChar { it.titlecase(Locale.getDefault()) }
- * String extension functions - to keep calling code readable following upgrade to Kotlin 1.9
- */
-fun String.capitalize() : String {
-    return this.replaceFirstChar { it.titlecase(Locale.getDefault()) }
-}
-fun String.decapitalize() : String {
-    return this.replaceFirstChar { it.lowercase(Locale.getDefault()) }
-}
 
+fun String.decapitalize(): String = replaceFirstChar { it.lowercase(Locale.getDefault()) }

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

@@ -94,7 +94,7 @@ class ResolveTransactionsFlow private constructor(
     fun fetchMissingAttachments(transaction: SignedTransaction): Boolean {
         val tx = transaction.coreTransaction
         val attachmentIds = when (tx) {
-            is WireTransaction -> tx.attachments.toSet()
+            is WireTransaction -> tx.allAttachments
             is ContractUpgradeWireTransaction -> setOf(tx.legacyContractAttachmentId, tx.upgradedContractAttachmentId)
             else -> return false
         }

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

@@ -1,6 +1,27 @@
 package net.corda.core.internal
 
-import net.corda.core.contracts.*
+import net.corda.core.contracts.Command
+import net.corda.core.contracts.CommandData
+import net.corda.core.contracts.ComponentGroupEnum
+import net.corda.core.contracts.ComponentGroupEnum.ATTACHMENTS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.ATTACHMENTS_V2_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.COMMANDS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.INPUTS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.NOTARY_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.OUTPUTS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.PARAMETERS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.REFERENCES_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.SIGNERS_GROUP
+import net.corda.core.contracts.ComponentGroupEnum.TIMEWINDOW_GROUP
+import net.corda.core.contracts.ContractClassName
+import net.corda.core.contracts.ContractState
+import net.corda.core.contracts.NamedByHash
+import net.corda.core.contracts.PrivacySalt
+import net.corda.core.contracts.StateAndRef
+import net.corda.core.contracts.StateRef
+import net.corda.core.contracts.TimeWindow
+import net.corda.core.contracts.TransactionState
+import net.corda.core.contracts.TransactionVerificationException
 import net.corda.core.crypto.DigestService
 import net.corda.core.crypto.SecureHash
 import net.corda.core.crypto.algorithm
@@ -8,8 +29,20 @@ import net.corda.core.crypto.internal.DigestAlgorithmFactory
 import net.corda.core.flows.FlowLogic
 import net.corda.core.identity.Party
 import net.corda.core.node.ServicesForResolution
-import net.corda.core.serialization.*
+import net.corda.core.serialization.MissingAttachmentsException
-import net.corda.core.transactions.*
+import net.corda.core.serialization.MissingAttachmentsRuntimeException
+import net.corda.core.serialization.SerializationContext
+import net.corda.core.serialization.SerializationFactory
+import net.corda.core.serialization.SerializedBytes
+import net.corda.core.serialization.deserialize
+import net.corda.core.serialization.serialize
+import net.corda.core.transactions.BaseTransaction
+import net.corda.core.transactions.ComponentGroup
+import net.corda.core.transactions.ContractUpgradeWireTransaction
+import net.corda.core.transactions.FilteredComponentGroup
+import net.corda.core.transactions.FullTransaction
+import net.corda.core.transactions.NotaryChangeWireTransaction
+import net.corda.core.transactions.SignedTransaction
 import net.corda.core.utilities.OpaqueBytes
 import java.io.ByteArrayOutputStream
 import java.security.PublicKey
@@ -68,8 +101,7 @@ fun <T : Any> deserialiseComponentGroup(componentGroups: List<ComponentGroup>,
                                         forceDeserialize: Boolean = false,
                                         factory: SerializationFactory = SerializationFactory.defaultFactory,
                                         context: SerializationContext = factory.defaultContext): List<T> {
-    val group = componentGroups.firstOrNull { it.groupIndex == groupEnum.ordinal }
+    val group = componentGroups.getGroup(groupEnum)
-
     if (group == null || group.components.isEmpty()) {
         return emptyList()
     }
@@ -85,7 +117,7 @@ fun <T : Any> deserialiseComponentGroup(componentGroups: List<ComponentGroup>,
             factory.deserialize(component, clazz.java, context)
         } catch (e: MissingAttachmentsException) {
             /**
-             * [ServiceHub.signInitialTransaction] forgets to declare that
+             * `ServiceHub.signInitialTransaction` forgets to declare that
              * it may throw any checked exceptions. Wrap this one inside
              * an unchecked version to avoid breaking Java CorDapps.
              */
@@ -96,7 +128,13 @@ fun <T : Any> deserialiseComponentGroup(componentGroups: List<ComponentGroup>,
     }
 }
 
-/**
+fun <T : ComponentGroup> List<T>.getGroup(type: ComponentGroupEnum): T? = firstOrNull { it.groupIndex == type.ordinal }
+
+fun <T : ComponentGroup> List<T>.getRequiredGroup(type: ComponentGroupEnum): T {
+    return requireNotNull(getGroup(type)) { "Missing component group $type" }
+}
+
+/**x
  * Exception raised if an error was encountered while attempting to deserialise a component group in a transaction.
  */
 class TransactionDeserialisationException(groupEnum: ComponentGroupEnum, index: Int, cause: Exception):
@@ -119,9 +157,9 @@ fun deserialiseCommands(
     // TODO: we could avoid deserialising unrelated signers.
     //      However, current approach ensures the transaction is not malformed
     //      and it will throw if any of the signers objects is not List of public keys).
-    val signersList: List<List<PublicKey>> = uncheckedCast(deserialiseComponentGroup(componentGroups, List::class, ComponentGroupEnum.SIGNERS_GROUP, forceDeserialize, factory, context))
+    val signersList: List<List<PublicKey>> = uncheckedCast(deserialiseComponentGroup(componentGroups, List::class, SIGNERS_GROUP, forceDeserialize, factory, context))
-    val commandDataList: List<CommandData> = deserialiseComponentGroup(componentGroups, CommandData::class, ComponentGroupEnum.COMMANDS_GROUP, forceDeserialize, factory, context)
+    val commandDataList: List<CommandData> = deserialiseComponentGroup(componentGroups, CommandData::class, COMMANDS_GROUP, forceDeserialize, factory, context)
-    val group = componentGroups.firstOrNull { it.groupIndex == ComponentGroupEnum.COMMANDS_GROUP.ordinal }
+    val group = componentGroups.getGroup(COMMANDS_GROUP)
     return if (group is FilteredComponentGroup) {
         check(commandDataList.size <= signersList.size) {
             "Invalid Transaction. Less Signers (${signersList.size}) than CommandData (${commandDataList.size}) objects"
@@ -141,10 +179,7 @@ fun deserialiseCommands(
     }
 }
 
-/**
+@Suppress("LongParameterList")
- * Creating list of [ComponentGroup] used in one of the constructors of [WireTransaction] required
- * for backwards compatibility purposes.
- */
 fun createComponentGroups(inputs: List<StateRef>,
                           outputs: List<TransactionState<ContractState>>,
                           commands: List<Command<*>>,
@@ -152,26 +187,37 @@ fun createComponentGroups(inputs: List<StateRef>,
                           notary: Party?,
                           timeWindow: TimeWindow?,
                           references: List<StateRef>,
-                          networkParametersHash: SecureHash?): List<ComponentGroup> {
+                          networkParametersHash: SecureHash?,
+                          // The old attachments group is now only used to create transaction compatible with 4.11 (or earlier) nodes
+                          legacyAttachments: List<SecureHash> = emptyList()): List<ComponentGroup> {
     val serializationFactory = SerializationFactory.defaultFactory
     val serializationContext = serializationFactory.defaultContext
     val serialize = { value: Any, _: Int -> value.serialize(serializationFactory, serializationContext) }
     val componentGroupMap: MutableList<ComponentGroup> = mutableListOf()
-    if (inputs.isNotEmpty()) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.INPUTS_GROUP.ordinal, inputs.lazyMapped(serialize)))
+    componentGroupMap.addListGroup(INPUTS_GROUP, inputs, serialize)
-    if (references.isNotEmpty()) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.REFERENCES_GROUP.ordinal, references.lazyMapped(serialize)))
+    componentGroupMap.addListGroup(REFERENCES_GROUP, references, serialize)
-    if (outputs.isNotEmpty()) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.OUTPUTS_GROUP.ordinal, outputs.lazyMapped(serialize)))
+    componentGroupMap.addListGroup(OUTPUTS_GROUP, outputs, serialize)
     // Adding commandData only to the commands group. Signers are added in their own group.
-    if (commands.isNotEmpty()) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.COMMANDS_GROUP.ordinal, commands.map { it.value }.lazyMapped(serialize)))
+    componentGroupMap.addListGroup(COMMANDS_GROUP, commands.map { it.value }, serialize)
-    if (attachments.isNotEmpty()) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.ATTACHMENTS_GROUP.ordinal, attachments.lazyMapped(serialize)))
+    // Attachments which can only be processed by 4.12 and later.
-    if (notary != null) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.NOTARY_GROUP.ordinal, listOf(notary).lazyMapped(serialize)))
+    componentGroupMap.addListGroup(ATTACHMENTS_V2_GROUP, attachments, serialize)
-    if (timeWindow != null) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.TIMEWINDOW_GROUP.ordinal, listOf(timeWindow).lazyMapped(serialize)))
+    // The original attachments group now only contains attachments which can be processed by 4.11 and ealier (and the external verifier).
+    componentGroupMap.addListGroup(ATTACHMENTS_GROUP, legacyAttachments, serialize)
+    if (notary != null) componentGroupMap.add(ComponentGroup(NOTARY_GROUP.ordinal, listOf(notary).lazyMapped(serialize)))
+    if (timeWindow != null) componentGroupMap.add(ComponentGroup(TIMEWINDOW_GROUP.ordinal, listOf(timeWindow).lazyMapped(serialize)))
     // Adding signers to their own group. This is required for command visibility purposes: a party receiving
     // a FilteredTransaction can now verify it sees all the commands it should sign.
-    if (commands.isNotEmpty()) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.SIGNERS_GROUP.ordinal, commands.map { it.signers }.lazyMapped(serialize)))
+    componentGroupMap.addListGroup(SIGNERS_GROUP, commands.map { it.signers }, serialize)
-    if (networkParametersHash != null) componentGroupMap.add(ComponentGroup(ComponentGroupEnum.PARAMETERS_GROUP.ordinal, listOf(networkParametersHash.serialize())))
+    if (networkParametersHash != null) componentGroupMap.add(ComponentGroup(PARAMETERS_GROUP.ordinal, listOf(networkParametersHash.serialize())))
     return componentGroupMap
 }
 
+private fun MutableList<ComponentGroup>.addListGroup(type: ComponentGroupEnum, list: List<Any>, serialize: (Any, Int) -> SerializedBytes<Any>) {
+    if (list.isNotEmpty()) {
+        add(ComponentGroup(type.ordinal, list.lazyMapped(serialize)))
+    }
+}
+
 typealias SerializedTransactionState = SerializedBytes<TransactionState<ContractState>>
 
 /**
@@ -267,10 +313,3 @@ internal fun checkNotaryWhitelisted(ftx: FullTransaction) {
         }
     }
 }
-
-val CoreTransaction.attachmentIds: List<SecureHash>
-    get() = when (this) {
-        is WireTransaction -> attachments
-        is ContractUpgradeWireTransaction -> listOf(legacyContractAttachmentId, upgradedContractAttachmentId)
-        else -> emptyList()
-    }

core/src/main/kotlin/net/corda/core/internal/cordapp/CordappImpl.kt

@@ -36,6 +36,7 @@ data class CordappImpl(
         override val minimumPlatformVersion: Int,
         override val targetPlatformVersion: Int,
         override val jarHash: SecureHash.SHA256 = jarFile.hash,
+        val languageVersion: LanguageVersion = LanguageVersion.Data,
         val notaryService: Class<out NotaryService>? = null,
         /** Indicates whether the CorDapp is loaded from external sources, or generated on node startup (virtual). */
         val isLoaded: Boolean = true,

core/src/main/kotlin/net/corda/core/internal/cordapp/CordappProviderInternal.kt

@@ -14,7 +14,10 @@ interface CordappProviderInternal : CordappProvider {
     fun getCordappForFlow(flowLogic: FlowLogic<*>): Cordapp?
 
     /**
-     * Similar to [getContractAttachmentID] except it returns the [ContractAttachment] object.
+     * Similar to [getContractAttachmentID] except it returns the [ContractAttachment] object and also returns an optional second attachment
+     * representing the legacy version (4.11 or earlier) of the contract, if one exists.
      */
-    fun getContractAttachment(contractClassName: ContractClassName): ContractAttachment?
+    fun getContractAttachments(contractClassName: ContractClassName): ContractAttachmentWithLegacy?
 }
+
+data class ContractAttachmentWithLegacy(val currentAttachment: ContractAttachment, val legacyAttachment: ContractAttachment? = null)

core/src/main/kotlin/net/corda/core/internal/cordapp/KotlinMetadataVersion.kt

@@ -0,0 +1,32 @@
+package net.corda.core.internal.cordapp
+
+data class KotlinMetadataVersion(val major: Int, val minor: Int, val patch: Int = 0) : Comparable<KotlinMetadataVersion> {
+    companion object {
+        fun from(versionArray: IntArray): KotlinMetadataVersion {
+            val (major, minor, patch) = versionArray
+            return KotlinMetadataVersion(major, minor, patch)
+        }
+    }
+
+    init {
+        require(major >= 0) { "Major version should be not less than 0" }
+        require(minor >= 0) { "Minor version should be not less than 0" }
+        require(patch >= 0) { "Patch version should be not less than 0" }
+    }
+
+    /**
+     * Returns the equivalent [KotlinVersion] without the patch.
+     */
+    val languageMinorVersion: KotlinVersion
+        // See `kotlinx.metadata.jvm.JvmMetadataVersion`
+        get() = if (major == 1 && minor == 1) KotlinVersion(1, 2) else KotlinVersion(major, minor)
+
+    override fun compareTo(other: KotlinMetadataVersion): Int {
+        val majors = this.major.compareTo(other.major)
+        if (majors != 0) return majors
+        val minors = this.minor.compareTo(other.minor)
+        return if (minors != 0) minors else this.patch.compareTo(other.patch)
+    }
+
+    override fun toString(): String = "$major.$minor.$patch"
+}

core/src/main/kotlin/net/corda/core/internal/cordapp/LanguageVersion.kt

@@ -0,0 +1,56 @@
+package net.corda.core.internal.cordapp
+
+import net.corda.core.internal.JAVA_17_CLASS_FILE_MAJOR_VERSION
+import net.corda.core.internal.JAVA_1_2_CLASS_FILE_MAJOR_VERSION
+import net.corda.core.internal.JAVA_8_CLASS_FILE_MAJOR_VERSION
+
+sealed class LanguageVersion {
+    /**
+     * Returns true if this version is compatible with Corda 4.11 or earlier.
+     */
+    abstract val isLegacyCompatible: Boolean
+
+    /**
+     * Returns true if this version is compatible with Corda 4.12 or later.
+     */
+    abstract val isNonLegacyCompatible: Boolean
+
+    @Suppress("ConvertObjectToDataObject")  // External verifier uses Kotlin 1.2
+    object Data : LanguageVersion() {
+        override val isLegacyCompatible: Boolean
+            get() = true
+
+        override val isNonLegacyCompatible: Boolean
+            get() = true
+
+        override fun toString(): String = "Data"
+    }
+
+    data class Bytecode(val classFileMajorVersion: Int, val kotlinMetadataVersion: KotlinMetadataVersion?): LanguageVersion() {
+        companion object {
+            private val KOTLIN_1_2_VERSION = KotlinVersion(1, 2)
+            private val KOTLIN_1_9_VERSION = KotlinVersion(1, 9)
+        }
+
+        init {
+            require(classFileMajorVersion in JAVA_1_2_CLASS_FILE_MAJOR_VERSION..JAVA_17_CLASS_FILE_MAJOR_VERSION) {
+                "Unsupported class file major version $classFileMajorVersion"
+            }
+            val kotlinVersion = kotlinMetadataVersion?.languageMinorVersion
+            require(kotlinVersion == null || kotlinVersion == KOTLIN_1_2_VERSION || kotlinVersion == KOTLIN_1_9_VERSION) {
+                "Unsupported Kotlin metadata version $kotlinMetadataVersion"
+            }
+        }
+
+        override val isLegacyCompatible: Boolean
+            get() = when {
+                classFileMajorVersion > JAVA_8_CLASS_FILE_MAJOR_VERSION -> false
+                kotlinMetadataVersion == null -> true  // Java 8 CorDapp is fine
+                else -> kotlinMetadataVersion.languageMinorVersion == KOTLIN_1_2_VERSION
+            }
+
+        override val isNonLegacyCompatible: Boolean
+            // Java-only CorDapp will always be compatible on 4.12
+            get() = if (kotlinMetadataVersion == null) true else kotlinMetadataVersion.languageMinorVersion == KOTLIN_1_9_VERSION
+    }
+}

core/src/main/kotlin/net/corda/core/internal/verification/NodeVerificationSupport.kt

@@ -1,7 +1,7 @@
 package net.corda.core.internal.verification
 
 import net.corda.core.contracts.Attachment
-import net.corda.core.contracts.ComponentGroupEnum
+import net.corda.core.contracts.ComponentGroupEnum.OUTPUTS_GROUP
 import net.corda.core.contracts.StateRef
 import net.corda.core.contracts.TransactionResolutionException
 import net.corda.core.crypto.SecureHash
@@ -11,6 +11,7 @@ import net.corda.core.internal.SerializedTransactionState
 import net.corda.core.internal.TRUSTED_UPLOADERS
 import net.corda.core.internal.cordapp.CordappProviderInternal
 import net.corda.core.internal.entries
+import net.corda.core.internal.getRequiredGroup
 import net.corda.core.internal.getRequiredTransaction
 import net.corda.core.node.NetworkParameters
 import net.corda.core.node.services.AttachmentStorage
@@ -85,9 +86,7 @@ interface NodeVerificationSupport : VerificationSupport {
 
     private fun getRegularOutput(coreTransaction: WireTransaction, outputIndex: Int): SerializedTransactionState {
         @Suppress("UNCHECKED_CAST")
-        return coreTransaction.componentGroups
+        return coreTransaction.componentGroups.getRequiredGroup(OUTPUTS_GROUP).components[outputIndex] as SerializedTransactionState
-                .first { it.groupIndex == ComponentGroupEnum.OUTPUTS_GROUP.ordinal }
-                .components[outputIndex] as SerializedTransactionState
     }
 
     /**
@@ -137,6 +136,8 @@ interface NodeVerificationSupport : VerificationSupport {
     override fun getTrustedClassAttachment(className: String): Attachment? {
         val allTrusted = attachments.queryAttachments(
                 AttachmentsQueryCriteria().withUploader(Builder.`in`(TRUSTED_UPLOADERS)),
+                // JarScanningCordappLoader makes sure legacy contract CorDapps have a coresponding non-legacy CorDapp, and that the
+                // legacy CorDapp has a smaller version number. Thus sorting by the version here ensures we never return the legacy attachment.
                 AttachmentSort(listOf(AttachmentSortColumn(AttachmentSortAttribute.VERSION, Sort.Direction.DESC)))
         )
 

core/src/main/kotlin/net/corda/core/internal/verification/VerificationSupport.kt

@@ -18,7 +18,7 @@ import java.security.PublicKey
  * Represents the operations required to resolve and verify a transaction.
  */
 interface VerificationSupport {
-    val isResolutionLazy: Boolean get() = true
+    val isInProcess: Boolean get() = true
 
     val appClassLoader: ClassLoader
 

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

@@ -8,8 +8,8 @@ import net.corda.core.contracts.TransactionVerificationException
 import net.corda.core.contracts.TransactionVerificationException.OverlappingAttachmentsException
 import net.corda.core.contracts.TransactionVerificationException.PackageOwnershipException
 import net.corda.core.crypto.SecureHash
-import net.corda.core.internal.JAVA_17_CLASS_FILE_FORMAT_MAJOR_VERSION
+import net.corda.core.internal.JAVA_17_CLASS_FILE_MAJOR_VERSION
-import net.corda.core.internal.JAVA_1_2_CLASS_FILE_FORMAT_MAJOR_VERSION
+import net.corda.core.internal.JAVA_1_2_CLASS_FILE_MAJOR_VERSION
 import net.corda.core.internal.JarSignatureCollector
 import net.corda.core.internal.NamedCacheFactory
 import net.corda.core.internal.PlatformVersionSwitches
@@ -340,7 +340,7 @@ object AttachmentsClassLoaderBuilder {
             val transactionClassLoader = AttachmentsClassLoader(attachments, key.params, txId, isAttachmentTrusted, parent)
             val serializers = try {
                 createInstancesOfClassesImplementing(transactionClassLoader, SerializationCustomSerializer::class.java,
-                        JAVA_1_2_CLASS_FILE_FORMAT_MAJOR_VERSION..JAVA_17_CLASS_FILE_FORMAT_MAJOR_VERSION)
+                        JAVA_1_2_CLASS_FILE_MAJOR_VERSION..JAVA_17_CLASS_FILE_MAJOR_VERSION)
             } catch (ex: UnsupportedClassVersionError) {
                 throw TransactionVerificationException.UnsupportedClassVersionError(txId, ex.message!!, ex)
             }

core/src/main/kotlin/net/corda/core/transactions/MerkleTransaction.kt

@@ -1,12 +1,15 @@
 package net.corda.core.transactions
 
 import net.corda.core.CordaException
+import net.corda.core.CordaInternal
 import net.corda.core.contracts.*
 import net.corda.core.contracts.ComponentGroupEnum.*
 import net.corda.core.crypto.*
 import net.corda.core.identity.Party
 import net.corda.core.internal.deserialiseCommands
 import net.corda.core.internal.deserialiseComponentGroup
+import net.corda.core.internal.getGroup
+import net.corda.core.internal.getRequiredGroup
 import net.corda.core.serialization.CordaSerializable
 import net.corda.core.serialization.DeprecatedConstructorForDeserialization
 import net.corda.core.serialization.SerializedBytes
@@ -29,8 +32,34 @@ abstract class TraversableTransaction(open val componentGroups: List<ComponentGr
     @DeprecatedConstructorForDeserialization(1)
     constructor(componentGroups: List<ComponentGroup>) : this(componentGroups, DigestService.sha2_256)
 
+    /**
+     * Returns the attachments compatible with 4.11 and earlier. This may be empty, which means this transaction cannot be verified by a
+     * 4.11 node. On 4.12 and later these attachments are ignored.
+     */
+    val legacyAttachments: List<SecureHash> = deserialiseComponentGroup(componentGroups, SecureHash::class, ATTACHMENTS_GROUP)
+
+    /**
+     * Returns the attachments compatible with 4.12 and later. This will be empty for transactions created on 4.11 or earlier.
+     *
+     * [legacyAttachments] and [nonLegacyAttachments] are independent of each other and may contain the same attachments. This is to provide backwards
+     * compatiblity and enable both 4.11 and 4.12 nodes to verify the same transaction.
+     */
+    @CordaInternal
+    @JvmSynthetic
+    internal val nonLegacyAttachments: List<SecureHash> = deserialiseComponentGroup(componentGroups, SecureHash::class, ATTACHMENTS_V2_GROUP)
+
     /** Hashes of the ZIP/JAR files that are needed to interpret the contents of this wire transaction. */
-    val attachments: List<SecureHash> = deserialiseComponentGroup(componentGroups, SecureHash::class, ATTACHMENTS_GROUP)
+    val attachments: List<SecureHash>
+        get() = when {
+            legacyAttachments.isEmpty() -> nonLegacyAttachments  // 4.12+ only transaction
+            nonLegacyAttachments.isEmpty() -> legacyAttachments  // 4.11 or earlier transaction
+            else -> nonLegacyAttachments  // This is a backwards compatible transaction, but from an API PoV we're not concerned with the legacy attachments
+        }
+
+    @CordaInternal
+    internal val allAttachments: Set<SecureHash>
+        @JvmSynthetic
+        get() = legacyAttachments.toMutableSet().apply { addAll(nonLegacyAttachments) }
 
     /** Pointers to the input states on the ledger, identified by (tx identity hash, output index). */
     override val inputs: List<StateRef> = deserialiseComponentGroup(componentGroups, StateRef::class, INPUTS_GROUP)
@@ -67,18 +96,20 @@ abstract class TraversableTransaction(open val componentGroups: List<ComponentGr
      * - list of each input that is present
      * - list of each output that is present
      * - list of each command that is present
-     * - list of each attachment that is present
+     * - list of each legacy attachment that is present (only relevant if transaction is being verified on a legacy node)
      * - The notary [Party], if present (list with one element)
      * - The time-window of the transaction, if present (list with one element)
      * - list of each reference input that is present
      * - network parameters hash if present
+     * - list of each attachment that is present
      */
     val availableComponentGroups: List<List<Any>>
         get() {
-            val result = mutableListOf(inputs, outputs, commands, attachments, references)
+            val result = mutableListOf(inputs, outputs, commands, legacyAttachments, references)
             notary?.let { result += listOf(it) }
             timeWindow?.let { result += listOf(it) }
             networkParametersHash?.let { result += listOf(it) }
+            result += nonLegacyAttachments
             return result
         }
 }
@@ -153,12 +184,10 @@ class FilteredTransaction internal constructor(
                 // This is required for visibility purposes, see FilteredTransaction.checkAllCommandsVisible() for more details.
                 if (componentGroupIndex == COMMANDS_GROUP.ordinal && !signersIncluded) {
                     signersIncluded = true
-                    val signersGroupIndex = SIGNERS_GROUP.ordinal
                     // There exist commands, thus the signers group is not empty.
-                    val signersGroupComponents = wtx.componentGroups.first { it.groupIndex == signersGroupIndex }
+                    filteredSerialisedComponents[SIGNERS_GROUP.ordinal] = wtx.componentGroups.getRequiredGroup(SIGNERS_GROUP).components.toMutableList()
-                    filteredSerialisedComponents[signersGroupIndex] = signersGroupComponents.components.toMutableList()
+                    filteredComponentNonces[SIGNERS_GROUP.ordinal] = wtx.availableComponentNonces[SIGNERS_GROUP.ordinal]!!.toMutableList()
-                    filteredComponentNonces[signersGroupIndex] = wtx.availableComponentNonces[signersGroupIndex]!!.toMutableList()
+                    filteredComponentHashes[SIGNERS_GROUP.ordinal] = wtx.availableComponentHashes[SIGNERS_GROUP.ordinal]!!.toMutableList()
-                    filteredComponentHashes[signersGroupIndex] = wtx.availableComponentHashes[signersGroupIndex]!!.toMutableList()
                 }
             }
 
@@ -166,7 +195,8 @@ class FilteredTransaction internal constructor(
                 wtx.inputs.forEachIndexed { internalIndex, it -> filter(it, INPUTS_GROUP.ordinal, internalIndex) }
                 wtx.outputs.forEachIndexed { internalIndex, it -> filter(it, OUTPUTS_GROUP.ordinal, internalIndex) }
                 wtx.commands.forEachIndexed { internalIndex, it -> filter(it, COMMANDS_GROUP.ordinal, internalIndex) }
-                wtx.attachments.forEachIndexed { internalIndex, it -> filter(it, ATTACHMENTS_GROUP.ordinal, internalIndex) }
+                wtx.legacyAttachments.forEachIndexed { internalIndex, it -> filter(it, ATTACHMENTS_GROUP.ordinal, internalIndex) }
+                wtx.nonLegacyAttachments.forEachIndexed { internalIndex, it -> filter(it, ATTACHMENTS_V2_GROUP.ordinal, internalIndex) }
                 if (wtx.notary != null) filter(wtx.notary, NOTARY_GROUP.ordinal, 0)
                 if (wtx.timeWindow != null) filter(wtx.timeWindow, TIMEWINDOW_GROUP.ordinal, 0)
                 // Note that because [inputs] and [references] share the same type [StateRef], we use a wrapper for references [ReferenceStateRef],
@@ -269,7 +299,7 @@ class FilteredTransaction internal constructor(
      */
     @Throws(ComponentVisibilityException::class)
     fun checkAllComponentsVisible(componentGroupEnum: ComponentGroupEnum) {
-        val group = filteredComponentGroups.firstOrNull { it.groupIndex == componentGroupEnum.ordinal }
+        val group = filteredComponentGroups.getGroup(componentGroupEnum)
         if (group == null) {
             // If we don't receive elements of a particular component, check if its ordinal is bigger that the
             // groupHashes.size or if the group hash is allOnesHash,
@@ -300,7 +330,7 @@ class FilteredTransaction internal constructor(
      */
     @Throws(ComponentVisibilityException::class)
     fun checkCommandVisibility(publicKey: PublicKey) {
-        val commandSigners = componentGroups.firstOrNull { it.groupIndex == SIGNERS_GROUP.ordinal }
+        val commandSigners = componentGroups.getGroup(SIGNERS_GROUP)
         val expectedNumOfCommands = expectedNumOfCommands(publicKey, commandSigners)
         val receivedForThisKeyNumOfCommands = commands.filter { publicKey in it.signers }.size
         visibilityCheck(expectedNumOfCommands == receivedForThisKeyNumOfCommands) {

core/src/main/kotlin/net/corda/core/transactions/SignedTransaction.kt

@@ -18,10 +18,8 @@ import net.corda.core.crypto.toStringShort
 import net.corda.core.identity.Party
 import net.corda.core.internal.TransactionDeserialisationException
 import net.corda.core.internal.VisibleForTesting
-import net.corda.core.internal.attachmentIds
 import net.corda.core.internal.equivalent
 import net.corda.core.internal.isUploaderTrusted
-import net.corda.core.internal.kotlinMetadataVersion
 import net.corda.core.internal.verification.NodeVerificationSupport
 import net.corda.core.internal.verification.VerificationSupport
 import net.corda.core.internal.verification.toVerifyingServiceHub
@@ -33,6 +31,9 @@ import net.corda.core.serialization.SerializedBytes
 import net.corda.core.serialization.deserialize
 import net.corda.core.serialization.internal.MissingSerializerException
 import net.corda.core.serialization.serialize
+import net.corda.core.utilities.Try
+import net.corda.core.utilities.Try.Failure
+import net.corda.core.utilities.Try.Success
 import net.corda.core.utilities.contextLogger
 import net.corda.core.utilities.debug
 import java.io.NotSerializableException
@@ -204,37 +205,58 @@ data class SignedTransaction(val txBits: SerializedBytes<CoreTransaction>,
      *
      * Depending on the contract attachments, this method will either verify this transaction in-process or send it to the external verifier
      * for out-of-process verification.
+     *
+     * @return The [FullTransaction] that was successfully verified in-process. Returns null if the verification was successfully done externally.
      */
     @CordaInternal
     @JvmSynthetic
-    fun verifyInternal(verificationSupport: NodeVerificationSupport, checkSufficientSignatures: Boolean = true) {
+    internal fun verifyInternal(verificationSupport: NodeVerificationSupport, checkSufficientSignatures: Boolean = true): FullTransaction? {
         resolveAndCheckNetworkParameters(verificationSupport)
-        val verificationType = determineVerificationType(verificationSupport)
+        val verificationType = determineVerificationType()
         log.debug { "Transaction $id has verification type $verificationType" }
-        if (verificationType == VerificationType.IN_PROCESS || verificationType == VerificationType.BOTH) {
+        return when (verificationType) {
-            verifyInProcess(verificationSupport, checkSufficientSignatures)
+            VerificationType.IN_PROCESS -> verifyInProcess(verificationSupport, checkSufficientSignatures)
-        }
+            VerificationType.BOTH -> {
-        if (verificationType == VerificationType.EXTERNAL || verificationType == VerificationType.BOTH) {
+                val inProcessResult = Try.on { verifyInProcess(verificationSupport, checkSufficientSignatures) }
-            verificationSupport.externalVerifierHandle.verifyTransaction(this, checkSufficientSignatures)
+                val externalResult = Try.on { verificationSupport.externalVerifierHandle.verifyTransaction(this, checkSufficientSignatures) }
+                ensureSameResult(inProcessResult, externalResult)
+            }
+            VerificationType.EXTERNAL -> {
+                verificationSupport.externalVerifierHandle.verifyTransaction(this, checkSufficientSignatures)
+                // We could create a LedgerTransaction here, and except for calling `verify()`, it would be valid to use. However, it's best
+                // we let the caller deal with that, since we can't control what they will do with it.
+                null
+            }
         }
     }
 
-    private fun determineVerificationType(verificationSupport: VerificationSupport): VerificationType {
+    private fun determineVerificationType(): VerificationType {
-        var old = false
+        val ctx = coreTransaction
-        var new = false
+        return when (ctx) {
-        for (attachmentId in coreTransaction.attachmentIds) {
+            is WireTransaction -> {
-            val (major, minor) = verificationSupport.getAttachment(attachmentId)?.kotlinMetadataVersion?.split(".") ?: continue
+                when {
-            // Metadata version 1.1 maps to language versions 1.0 to 1.3
+                    ctx.legacyAttachments.isEmpty() -> VerificationType.IN_PROCESS
-            if (major == "1" && minor == "1") {
+                    ctx.nonLegacyAttachments.isEmpty() -> VerificationType.EXTERNAL
-                old = true
+                    else -> VerificationType.BOTH
-            } else {
+                }
-                new = true
             }
+            // Contract upgrades only work on 4.11 and earlier
+            is ContractUpgradeWireTransaction -> VerificationType.EXTERNAL
+            else -> VerificationType.IN_PROCESS  // The default is always in-process
         }
-        return when {
+    }
-            old && new -> VerificationType.BOTH
+
-            old -> VerificationType.EXTERNAL
+    private fun ensureSameResult(inProcessResult: Try<FullTransaction>, externalResult: Try<*>): FullTransaction {
-            else -> VerificationType.IN_PROCESS
+        return when (externalResult) {
+            is Success -> when (inProcessResult) {
+                is Success -> inProcessResult.value
+                is Failure -> throw IllegalStateException("In-process verification of $id failed, but it succeeded in external verifier")
+                        .apply { addSuppressed(inProcessResult.exception) }
+            }
+            is Failure -> throw when (inProcessResult) {
+                is Success -> IllegalStateException("In-process verification of $id succeeded, but it failed in external verifier")
+                is Failure -> inProcessResult.exception  // Throw the in-process exception, with the external exception suppressed
+            }.apply { addSuppressed(externalResult.exception) }
         }
     }
 
@@ -244,11 +266,13 @@ data class SignedTransaction(val txBits: SerializedBytes<CoreTransaction>,
 
     /**
      * Verifies this transaction in-process. This assumes the current process has the correct classpath for all the contracts.
+     *
+     * @return The [FullTransaction] that was successfully verified
      */
     @CordaInternal
     @JvmSynthetic
-    fun verifyInProcess(verificationSupport: VerificationSupport, checkSufficientSignatures: Boolean) {
+    internal fun verifyInProcess(verificationSupport: VerificationSupport, checkSufficientSignatures: Boolean): FullTransaction {
-        when (coreTransaction) {
+        return when (coreTransaction) {
             is NotaryChangeWireTransaction -> verifyNotaryChangeTransaction(verificationSupport, checkSufficientSignatures)
             is ContractUpgradeWireTransaction -> verifyContractUpgradeTransaction(verificationSupport, checkSufficientSignatures)
             else -> verifyRegularTransaction(verificationSupport, checkSufficientSignatures)
@@ -272,23 +296,25 @@ data class SignedTransaction(val txBits: SerializedBytes<CoreTransaction>,
     }
 
     /** No contract code is run when verifying notary change transactions, it is sufficient to check invariants during initialisation. */
-    private fun verifyNotaryChangeTransaction(verificationSupport: VerificationSupport, checkSufficientSignatures: Boolean) {
+    private fun verifyNotaryChangeTransaction(verificationSupport: VerificationSupport, checkSufficientSignatures: Boolean): NotaryChangeLedgerTransaction {
         val ntx = NotaryChangeLedgerTransaction.resolve(verificationSupport, coreTransaction as NotaryChangeWireTransaction, sigs)
         if (checkSufficientSignatures) ntx.verifyRequiredSignatures()
         else checkSignaturesAreValid()
+        return ntx
     }
 
     /** No contract code is run when verifying contract upgrade transactions, it is sufficient to check invariants during initialisation. */
-    private fun verifyContractUpgradeTransaction(verificationSupport: VerificationSupport, checkSufficientSignatures: Boolean) {
+    private fun verifyContractUpgradeTransaction(verificationSupport: VerificationSupport, checkSufficientSignatures: Boolean): ContractUpgradeLedgerTransaction {
         val ctx = ContractUpgradeLedgerTransaction.resolve(verificationSupport, coreTransaction as ContractUpgradeWireTransaction, sigs)
         if (checkSufficientSignatures) ctx.verifyRequiredSignatures()
         else checkSignaturesAreValid()
+        return ctx
     }
 
     // TODO: Verify contract constraints here as well as in LedgerTransaction to ensure that anything being deserialised
     // from the attachment is trusted. This will require some partial serialisation work to not load the ContractState
     // objects from the TransactionState.
-    private fun verifyRegularTransaction(verificationSupport: VerificationSupport, checkSufficientSignatures: Boolean) {
+    private fun verifyRegularTransaction(verificationSupport: VerificationSupport, checkSufficientSignatures: Boolean): LedgerTransaction {
         val ltx = toLedgerTransactionInternal(verificationSupport, checkSufficientSignatures)
         try {
             ltx.verify()
@@ -304,6 +330,7 @@ data class SignedTransaction(val txBits: SerializedBytes<CoreTransaction>,
             checkReverifyAllowed(e)
             retryVerification(e.cause, e, ltx, verificationSupport)
         }
+        return ltx
     }
 
     private fun checkReverifyAllowed(ex: Throwable) {

core/src/main/kotlin/net/corda/core/transactions/TransactionBuilder.kt

@@ -9,6 +9,7 @@ import net.corda.core.crypto.SignatureMetadata
 import net.corda.core.identity.Party
 import net.corda.core.internal.*
 import net.corda.core.internal.PlatformVersionSwitches.MIGRATE_ATTACHMENT_TO_SIGNATURE_CONSTRAINTS
+import net.corda.core.internal.cordapp.ContractAttachmentWithLegacy
 import net.corda.core.internal.verification.VerifyingServiceHub
 import net.corda.core.internal.verification.toVerifyingServiceHub
 import net.corda.core.node.NetworkParameters
@@ -152,7 +153,7 @@ open class TransactionBuilder(
      */
     @Throws(MissingContractAttachments::class)
     fun toWireTransaction(services: ServicesForResolution, schemeId: Int): WireTransaction {
-        return toWireTransaction(services, schemeId, emptyMap()).apply { checkSupportedHashType() }
+        return toWireTransaction(services, schemeId, emptyMap())
     }
 
     /**
@@ -195,7 +196,7 @@ open class TransactionBuilder(
 
         val wireTx = SerializationFactory.defaultFactory.withCurrentContext(serializationContext) {
             // Sort the attachments to ensure transaction builds are stable.
-            val attachmentsBuilder = allContractAttachments.mapTo(TreeSet()) { it.id }
+            val attachmentsBuilder = allContractAttachments.mapTo(TreeSet()) { it.currentAttachment.id }
             attachmentsBuilder.addAll(attachments)
             attachmentsBuilder.removeAll(excludedAttachments)
             WireTransaction(
@@ -207,7 +208,8 @@ open class TransactionBuilder(
                             notary,
                             window,
                             referenceStates,
-                            serviceHub.networkParametersService.currentHash
+                            serviceHub.networkParametersService.currentHash,
+                            allContractAttachments.mapNotNullTo(TreeSet()) { it.legacyAttachment?.id }.toList()
                     ),
                     privacySalt,
                     serviceHub.digestService
@@ -237,6 +239,7 @@ open class TransactionBuilder(
     /**
      * @return true if a new dependency was successfully added.
      */
+    // TODO This entire code path needs to be updated to work with legacy attachments and automically adding their dependencies. ENT-11445
     private fun addMissingDependency(serviceHub: VerifyingServiceHub, wireTx: WireTransaction, tryCount: Int): Boolean {
         return try {
             wireTx.toLedgerTransactionInternal(serviceHub).verify()
@@ -249,11 +252,14 @@ open class TransactionBuilder(
                 // Handle various exceptions that can be thrown during verification and drill down the wrappings.
                 // Note: this is a best effort to preserve backwards compatibility.
                 rootError is ClassNotFoundException -> {
-                    ((tryCount == 0) && fixupAttachments(wireTx.attachments, serviceHub, e))
+                    // Using nonLegacyAttachments here as the verification above was done in-process and thus only the nonLegacyAttachments
+                    // are used.
+                    // TODO This might change with ENT-11445 where we add support for legacy contract dependencies.
+                    ((tryCount == 0) && fixupAttachments(wireTx.nonLegacyAttachments, serviceHub, e))
                         || addMissingAttachment((rootError.message ?: throw e).replace('.', '/'), serviceHub, e)
                 }
                 rootError is NoClassDefFoundError -> {
-                    ((tryCount == 0) && fixupAttachments(wireTx.attachments, serviceHub, e))
+                    ((tryCount == 0) && fixupAttachments(wireTx.nonLegacyAttachments, serviceHub, e))
                         || addMissingAttachment(rootError.message ?: throw e, serviceHub, e)
                 }
 
@@ -347,7 +353,7 @@ open class TransactionBuilder(
      */
     private fun selectContractAttachmentsAndOutputStateConstraints(
             serviceHub: VerifyingServiceHub
-    ): Pair<List<ContractAttachment>, List<TransactionState<*>>> {
+    ): Pair<List<ContractAttachmentWithLegacy>, List<TransactionState<*>>> {
         // Determine the explicitly set contract attachments.
         val explicitContractToAttachments = attachments
                 .mapNotNull { serviceHub.attachments.openAttachment(it) as? ContractAttachment }
@@ -367,7 +373,7 @@ open class TransactionBuilder(
                 = referencesWithTransactionState.groupBy { it.contract }
         val refStateContractAttachments = referenceStateGroups
                 .filterNot { it.key in allContracts }
-                .map { refStateEntry -> serviceHub.getInstalledContractAttachment(refStateEntry.key, refStateEntry::value) }
+                .map { refStateEntry -> serviceHub.getInstalledContractAttachments(refStateEntry.key, refStateEntry::value) }
 
         // For each contract, resolve the AutomaticPlaceholderConstraint, and select the attachment.
         val contractAttachmentsAndResolvedOutputStates = allContracts.map { contract ->
@@ -413,10 +419,10 @@ open class TransactionBuilder(
             outputStates: List<TransactionState<ContractState>>?,
             explicitContractAttachment: ContractAttachment?,
             serviceHub: VerifyingServiceHub
-    ): Pair<ContractAttachment, List<TransactionState<*>>> {
+    ): Pair<ContractAttachmentWithLegacy, List<TransactionState<*>>> {
         val inputsAndOutputs = (inputStates ?: emptyList()) + (outputStates ?: emptyList())
 
-        fun selectAttachmentForContract() = serviceHub.getInstalledContractAttachment(contractClassName) {
+        fun selectAttachmentForContract() = serviceHub.getInstalledContractAttachments(contractClassName) {
             inputsAndOutputs.filterNot { it.constraint in automaticConstraints }
         }
 
@@ -429,14 +435,15 @@ open class TransactionBuilder(
         a system parameter that disables the hash constraint check.
         */
         if (canMigrateFromHashToSignatureConstraint(inputStates, outputStates, serviceHub)) {
-            val attachment = selectAttachmentForContract()
+            val attachmentWithLegacy = selectAttachmentForContract()
+            val (attachment) = attachmentWithLegacy
             if (attachment.isSigned && (explicitContractAttachment == null || explicitContractAttachment.id == attachment.id)) {
                 val signatureConstraint = makeSignatureAttachmentConstraint(attachment.signerKeys)
                 require(signatureConstraint.isSatisfiedBy(attachment)) { "Selected output constraint: $signatureConstraint not satisfying ${attachment.id}" }
                 val resolvedOutputStates = outputStates?.map {
                     if (it.constraint in automaticConstraints) it.copy(constraint = signatureConstraint) else it
                 } ?: emptyList()
-                return attachment to resolvedOutputStates
+                return attachmentWithLegacy to resolvedOutputStates
             }
         }
 
@@ -467,9 +474,9 @@ open class TransactionBuilder(
                 }
             }
             // This *has* to be used by this transaction as it is explicit
-            explicitContractAttachment
+            ContractAttachmentWithLegacy(explicitContractAttachment, null)  // By definition there can be no legacy version
         } else {
-            hashAttachment ?: selectAttachmentForContract()
+            hashAttachment?.let { ContractAttachmentWithLegacy(it, null) } ?: selectAttachmentForContract()
         }
 
         // For Exit transactions (no output states) there is no need to resolve the output constraints.
@@ -491,10 +498,10 @@ open class TransactionBuilder(
         }
 
         // This is the logic to determine the constraint which will replace the AutomaticPlaceholderConstraint.
-        val defaultOutputConstraint = selectAttachmentConstraint(contractClassName, inputStates, selectedAttachment, serviceHub)
+        val defaultOutputConstraint = selectAttachmentConstraint(contractClassName, inputStates, selectedAttachment.currentAttachment, serviceHub)
 
         // Sanity check that the selected attachment actually passes.
-        val constraintAttachment = AttachmentWithContext(selectedAttachment, contractClassName, serviceHub.networkParameters.whitelistedContractImplementations)
+        val constraintAttachment = AttachmentWithContext(selectedAttachment.currentAttachment, contractClassName, serviceHub.networkParameters.whitelistedContractImplementations)
         require(defaultOutputConstraint.isSatisfiedBy(constraintAttachment)) {
             "Selected output constraint: $defaultOutputConstraint not satisfying $selectedAttachment"
         }
@@ -506,7 +513,7 @@ open class TransactionBuilder(
             } else {
                 // If the constraint on the output state is already set, and is not a valid transition or can't be transitioned, then fail early.
                 inputStates?.forEach { input ->
-                    require(outputConstraint.canBeTransitionedFrom(input.constraint, selectedAttachment)) {
+                    require(outputConstraint.canBeTransitionedFrom(input.constraint, selectedAttachment.currentAttachment)) {
                         "Output state constraint $outputConstraint cannot be transitioned from ${input.constraint}"
                     }
                 }
@@ -629,12 +636,18 @@ open class TransactionBuilder(
             SignatureAttachmentConstraint.create(CompositeKey.Builder().addKeys(attachmentSigners)
                     .build())
 
-    private inline fun VerifyingServiceHub.getInstalledContractAttachment(
+    private inline fun VerifyingServiceHub.getInstalledContractAttachments(
             contractClassName: String,
             statesForException: () -> List<TransactionState<*>>
-    ): ContractAttachment {
+    ): ContractAttachmentWithLegacy {
-        return cordappProvider.getContractAttachment(contractClassName)
+        // TODO Stop using legacy attachments when the 4.12 min platform version is reached https://r3-cev.atlassian.net/browse/ENT-11479
+        val attachmentWithLegacy = cordappProvider.getContractAttachments(contractClassName)
                 ?: throw MissingContractAttachments(statesForException(), contractClassName)
+        if (attachmentWithLegacy.legacyAttachment == null) {
+            log.warnOnce("Contract $contractClassName does not have a legacy (4.11 or earlier) version installed. This means the " +
+                    "transaction will not be compatible with older nodes.")
+        }
+        return attachmentWithLegacy
     }
 
     private fun useWhitelistedByZoneAttachmentConstraint(contractClassName: ContractClassName, networkParameters: NetworkParameters): Boolean {
@@ -646,6 +659,7 @@ open class TransactionBuilder(
 
     @Throws(AttachmentResolutionException::class, TransactionResolutionException::class, TransactionVerificationException::class)
     fun verify(services: ServiceHub) {
+        // TODO ENT-11445: Need to verify via SignedTransaction to ensure legacy components also work
         toLedgerTransaction(services).verify()
     }
 

core/src/main/kotlin/net/corda/core/transactions/WireTransaction.kt

@@ -25,6 +25,7 @@ import net.corda.core.internal.SerializedStateAndRef
 import net.corda.core.internal.SerializedTransactionState
 import net.corda.core.internal.createComponentGroups
 import net.corda.core.internal.flatMapToSet
+import net.corda.core.internal.getGroup
 import net.corda.core.internal.isUploaderTrusted
 import net.corda.core.internal.lazyMapped
 import net.corda.core.internal.mapToSet
@@ -162,7 +163,7 @@ class WireTransaction(componentGroups: List<ComponentGroup>, val privacySalt: Pr
     @JvmSynthetic
     fun toLedgerTransactionInternal(verificationSupport: VerificationSupport): LedgerTransaction {
         // Look up public keys to authenticated identities.
-        val authenticatedCommands = if (verificationSupport.isResolutionLazy) {
+        val authenticatedCommands = if (verificationSupport.isInProcess) {
             commands.lazyMapped { cmd, _ ->
                 val parties = verificationSupport.getParties(cmd.signers).filterNotNull()
                 CommandWithParties(cmd.signers, parties, cmd.value)
@@ -193,13 +194,15 @@ class WireTransaction(componentGroups: List<ComponentGroup>, val privacySalt: Pr
         }
         val resolvedReferences = serializedResolvedReferences.lazyMapped(toStateAndRef)
 
-        val resolvedAttachments = if (verificationSupport.isResolutionLazy) {
+        val resolvedAttachments = if (verificationSupport.isInProcess) {
-            attachments.lazyMapped { id, _ ->
+            // The 4.12+ node only looks at the new attachments group
+            nonLegacyAttachments.lazyMapped { id, _ ->
                 verificationSupport.getAttachment(id) ?: throw AttachmentResolutionException(id)
             }
         } else {
-            verificationSupport.getAttachments(attachments).mapIndexed { index, attachment ->
+            // The 4.11 external verifier only looks at the legacy attachments group since it will only contain attachments compatible with 4.11
-                attachment ?: throw AttachmentResolutionException(attachments[index])
+            verificationSupport.getAttachments(legacyAttachments).mapIndexed { index, attachment ->
+                attachment ?: throw AttachmentResolutionException(legacyAttachments[index])
             }
         }
 
@@ -248,7 +251,7 @@ class WireTransaction(componentGroups: List<ComponentGroup>, val privacySalt: Pr
 
         // This calculates a value that is slightly lower than the actual re-serialized version. But it is stable and does not depend on the classloader.
         fun componentGroupSize(componentGroup: ComponentGroupEnum): Int {
-            return this.componentGroups.firstOrNull { it.groupIndex == componentGroup.ordinal }?.let { cg -> cg.components.sumOf { it.size } + 4 } ?: 0
+            return componentGroups.getGroup(componentGroup)?.let { cg -> cg.components.sumOf { it.size } + 4 } ?: 0
         }
 
         // Check attachments size first as they are most likely to go over the limit. With ContractAttachment instances
@@ -320,10 +323,10 @@ class WireTransaction(componentGroups: List<ComponentGroup>, val privacySalt: Pr
      * nothing about the rest.
      */
     internal val availableComponentNonces: Map<Int, List<SecureHash>> by lazy {
-        if(digestService.hashAlgorithm == SecureHash.SHA2_256) {
+        if (digestService.hashAlgorithm == SecureHash.SHA2_256) {
             componentGroups.associate { it.groupIndex to it.components.mapIndexed { internalIndex, internalIt -> digestService.componentHash(internalIt, privacySalt, it.groupIndex, internalIndex) } }
         } else {
-            componentGroups.associate { it.groupIndex to it.components.mapIndexed { internalIndex, _ -> digestService.computeNonce(privacySalt, it.groupIndex, internalIndex) } }
+            componentGroups.associate { it.groupIndex to List(it.components.size) { internalIndex -> digestService.computeNonce(privacySalt, it.groupIndex, internalIndex) } }
         }
     }
 
@@ -343,23 +346,10 @@ class WireTransaction(componentGroups: List<ComponentGroup>, val privacySalt: Pr
      * @throws IllegalArgumentException if the signature key doesn't appear in any command.
      */
     fun checkSignature(sig: TransactionSignature) {
-        require(commands.any { it.signers.any { sig.by in it.keys } }) { "Signature key doesn't match any command" }
+        require(commands.any { it.signers.any { signer -> sig.by in signer.keys } }) { "Signature key doesn't match any command" }
         sig.verify(id)
     }
 
-    companion object {
-        @CordaInternal
-        @Deprecated("Do not use, this is internal API")
-        fun createComponentGroups(inputs: List<StateRef>,
-                                  outputs: List<TransactionState<ContractState>>,
-                                  commands: List<Command<*>>,
-                                  attachments: List<SecureHash>,
-                                  notary: Party?,
-                                  timeWindow: TimeWindow?): List<ComponentGroup> {
-            return createComponentGroups(inputs, outputs, commands, attachments, notary, timeWindow, emptyList(), null)
-        }
-    }
-
     override fun toString(): String {
         val buf = StringBuilder()
         buf.appendLine("Transaction:")

finance/contracts/build.gradle

@@ -51,7 +51,7 @@ cordapp {
     minimumPlatformVersion 1
     contract {
         name "Corda Finance Demo"
-        versionId 1
+        versionId 2
         vendor "R3"
         licence "Open Source (Apache 2)"
     }

node-api/src/main/kotlin/net/corda/nodeapi/internal/cordapp/CordappLoader.kt

@@ -14,6 +14,11 @@ interface CordappLoader : AutoCloseable {
      */
     val cordapps: List<CordappImpl>
 
+    /**
+     * Returns all legacy (4.11 or older) contract CorDapps. These are used to form backward compatible transactions.
+     */
+    val legacyContractCordapps: List<CordappImpl>
+
     /**
      * Returns a [ClassLoader] containing all types from all [Cordapp]s.
      */

node/build.gradle

@@ -23,8 +23,10 @@ configurations {
     integrationTestImplementation.extendsFrom testImplementation
     integrationTestRuntimeOnly.extendsFrom testRuntimeOnly
     
-    slowIntegrationTestCompile.extendsFrom testImplementation
+    slowIntegrationTestImplementation.extendsFrom testImplementation
     slowIntegrationTestRuntimeOnly.extendsFrom testRuntimeOnly
+
+    corda4_11
 }
 
 sourceSets {
@@ -89,6 +91,7 @@ processTestResources {
     from(tasks.getByPath(":testing:cordapps:cashobservers:jar")) {
         rename 'testing-cashobservers-cordapp-.*.jar', 'testing-cashobservers-cordapp.jar'
     }
+    from(configurations.corda4_11)
 }
 
 // To find potential version conflicts, run "gradle htmlDependencyReport" and then look in
@@ -104,30 +107,22 @@ dependencies {
     implementation project(':common-configuration-parsing')
     implementation project(':common-logging')
     implementation project(':serialization')
-
-    implementation "io.opentelemetry:opentelemetry-api:${open_telemetry_version}"
     // Backwards compatibility goo: Apps expect confidential-identities to be loaded by default.
     // We could eventually gate this on a target-version check.
     implementation project(':confidential-identities')
-
+    implementation "io.opentelemetry:opentelemetry-api:${open_telemetry_version}"
     // Log4J: logging framework (with SLF4J bindings)
     implementation "org.apache.logging.log4j:log4j-slf4j-impl:${log4j_version}"
     implementation "org.apache.logging.log4j:log4j-web:${log4j_version}"
     implementation "org.slf4j:jul-to-slf4j:$slf4j_version"
-
     implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
-    testImplementation "org.jetbrains.kotlin:kotlin-test:$kotlin_version"
-
     implementation "org.fusesource.jansi:jansi:$jansi_version"
     implementation "com.google.guava:guava:$guava_version"
     implementation "commons-io:commons-io:$commons_io_version"
-
     // For caches rather than guava
     implementation "com.github.ben-manes.caffeine:caffeine:$caffeine_version"
-
     // For async logging
     implementation "com.lmax:disruptor:$disruptor_version"
-
     // Artemis: for reliable p2p message queues.
     // TODO: remove the forced update of commons-collections and beanutils when artemis updates them
     implementation "org.apache.commons:commons-collections4:${commons_collections_version}"
@@ -142,92 +137,66 @@ dependencies {
     // Bouncy castle support needed for X509 certificate manipulation
     implementation "org.bouncycastle:bcprov-jdk18on:${bouncycastle_version}"
     implementation "org.bouncycastle:bcpkix-jdk18on:${bouncycastle_version}"
-
     implementation "com.esotericsoftware:kryo:$kryo_version"
-
     implementation "com.fasterxml.jackson.core:jackson-annotations:${jackson_version}"
     implementation "com.fasterxml.jackson.core:jackson-databind:$jackson_version"
-
-    runtimeOnly("org.apache.activemq:artemis-amqp-protocol:${artemis_version}") {
-        // Gains our proton-j version from core module.
-        exclude group: 'org.apache.qpid', module: 'proton-j'
-        exclude group: 'org.jgroups', module: 'jgroups'
-    }
-
     // Manifests: for reading stuff from the manifest file
     implementation "com.jcabi:jcabi-manifests:$jcabi_manifests_version"
-
     // Coda Hale's Metrics: for monitoring of key statistics
     implementation "io.dropwizard.metrics:metrics-jmx:$metrics_version"
     implementation "io.github.classgraph:classgraph:$class_graph_version"
     implementation "org.liquibase:liquibase-core:$liquibase_version"
-
     // TypeSafe Config: for simple and human friendly config files.
     implementation "com.typesafe:config:$typesafe_config_version"
-
     implementation "io.reactivex:rxjava:$rxjava_version"
-
     implementation("org.apache.activemq:artemis-amqp-protocol:${artemis_version}") {
         // Gains our proton-j version from core module.
         exclude group: 'org.apache.qpid', module: 'proton-j'
         exclude group: 'org.jgroups', module: 'jgroups'
     }
+    // For H2 database support in persistence
+    implementation "com.h2database:h2:$h2_version"
+    // SQL connection pooling library
+    implementation "com.zaxxer:HikariCP:${hikari_version}"
+    // Hibernate: an object relational mapper for writing state objects to the database automatically.
+    implementation "org.hibernate:hibernate-core:$hibernate_version"
+    implementation "org.hibernate:hibernate-java8:$hibernate_version"
+    // OkHTTP: Simple HTTP library.
+    implementation "com.squareup.okhttp3:okhttp:$okhttp_version"
+    // Apache Shiro: authentication, authorization and session management.
+    implementation "org.apache.shiro:shiro-core:${shiro_version}"
+    //Picocli for command line interface
+    implementation "info.picocli:picocli:$picocli_version"
+    // BFT-Smart dependencies
+    implementation 'com.github.bft-smart:library:master-v1.1-beta-g6215ec8-87'
+    // Java Atomix: RAFT library
+    implementation 'io.atomix.copycat:copycat-client:1.2.3'
+    implementation 'io.atomix.copycat:copycat-server:1.2.3'
+    implementation 'io.atomix.catalyst:catalyst-netty:1.1.2'
+    // Jolokia JVM monitoring agent, required to push logs through slf4j
+    implementation "org.jolokia:jolokia-jvm:${jolokia_version}:agent"
+    // Optional New Relic JVM reporter, used to push metrics to the configured account associated with a newrelic.yml configuration. See https://mvnrepository.com/artifact/com.palominolabs.metrics/metrics-new-relic
+    implementation "com.palominolabs.metrics:metrics-new-relic:${metrics_new_relic_version}"
+    // Adding native SSL library to allow using native SSL with Artemis and AMQP
+    implementation "io.netty:netty-tcnative-boringssl-static:$tcnative_version"
+    implementation 'org.jetbrains.kotlinx:kotlinx-metadata-jvm:0.8.0'
 
-    testImplementation "org.junit.jupiter:junit-jupiter-api:${junit_jupiter_version}"
+    testImplementation(project(':test-cli'))
-    testImplementation "junit:junit:$junit_version"
+    testImplementation(project(':test-utils'))
-
-    testRuntimeOnly "org.junit.vintage:junit-vintage-engine:${junit_vintage_version}"
-    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:${junit_jupiter_version}"
-    testRuntimeOnly "org.junit.platform:junit-platform-launcher:${junit_platform_version}"
-
     // Unit testing helpers.
-    testImplementation "org.assertj:assertj-core:${assertj_version}"
     testImplementation project(':node-driver')
     testImplementation project(':core-test-utils')
     testImplementation project(':test-utils')
     testImplementation project(':client:jfx')
     testImplementation project(':finance:contracts')
     testImplementation project(':finance:workflows')
-
     // sample test schemas
     testImplementation project(path: ':finance:contracts', configuration: 'testArtifacts')
-
+    testImplementation project(':testing:cordapps:dbfailure:dbfworkflows')
-    // For H2 database support in persistence
+    testImplementation "org.assertj:assertj-core:${assertj_version}"
-    implementation "com.h2database:h2:$h2_version"
+    testImplementation "org.jetbrains.kotlin:kotlin-test:$kotlin_version"
-
+    testImplementation "org.junit.jupiter:junit-jupiter-api:${junit_jupiter_version}"
-    // SQL connection pooling library
+    testImplementation "junit:junit:$junit_version"
-    implementation "com.zaxxer:HikariCP:${hikari_version}"
-
-    // Hibernate: an object relational mapper for writing state objects to the database automatically.
-    implementation "org.hibernate:hibernate-core:$hibernate_version"
-    implementation "org.hibernate:hibernate-java8:$hibernate_version"
-
-    // OkHTTP: Simple HTTP library.
-    implementation "com.squareup.okhttp3:okhttp:$okhttp_version"
-
-    // Apache Shiro: authentication, authorization and session management.
-    implementation "org.apache.shiro:shiro-core:${shiro_version}"
-
-    //Picocli for command line interface
-    implementation "info.picocli:picocli:$picocli_version"
-
-    integrationTestImplementation project(":testing:cordapps:dbfailure:dbfcontracts")
-
-    // Integration test helpers
-    integrationTestImplementation "de.javakaffee:kryo-serializers:$kryo_serializer_version"
-    integrationTestImplementation "junit:junit:$junit_version"
-    integrationTestImplementation "org.assertj:assertj-core:${assertj_version}"
-    integrationTestImplementation "org.apache.qpid:qpid-jms-client:${protonj_version}"
-    integrationTestImplementation "net.i2p.crypto:eddsa:$eddsa_version"
-
-    // BFT-Smart dependencies
-    implementation 'com.github.bft-smart:library:master-v1.1-beta-g6215ec8-87'
-
-    // Java Atomix: RAFT library
-    implementation 'io.atomix.copycat:copycat-client:1.2.3'
-    implementation 'io.atomix.copycat:copycat-server:1.2.3'
-    implementation 'io.atomix.catalyst:catalyst-netty:1.1.2'
-
     // Jetty dependencies for NetworkMapClient test.
     // Web stuff: for HTTP[S] servlets
     testImplementation "org.hamcrest:hamcrest-library:2.1"
@@ -238,43 +207,33 @@ dependencies {
     testImplementation "com.google.jimfs:jimfs:1.1"
     testImplementation "co.paralleluniverse:quasar-core:$quasar_version"
     testImplementation "com.natpryce:hamkrest:$hamkrest_version"
-
     // Jersey for JAX-RS implementation for use in Jetty
     testImplementation "org.glassfish.jersey.core:jersey-server:${jersey_version}"
     testImplementation "org.glassfish.jersey.containers:jersey-container-servlet-core:${jersey_version}"
     testImplementation "org.glassfish.jersey.containers:jersey-container-jetty-http:${jersey_version}"
 
-    // Jolokia JVM monitoring agent, required to push logs through slf4j
+    testRuntimeOnly "org.junit.vintage:junit-vintage-engine:${junit_vintage_version}"
-    implementation "org.jolokia:jolokia-jvm:${jolokia_version}:agent"
+    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:${junit_jupiter_version}"
-    // Optional New Relic JVM reporter, used to push metrics to the configured account associated with a newrelic.yml configuration. See https://mvnrepository.com/artifact/com.palominolabs.metrics/metrics-new-relic
+    testRuntimeOnly "org.junit.platform:junit-platform-launcher:${junit_platform_version}"
-    implementation "com.palominolabs.metrics:metrics-new-relic:${metrics_new_relic_version}"
-
-    // Adding native SSL library to allow using native SSL with Artemis and AMQP
-    implementation "io.netty:netty-tcnative-boringssl-static:$tcnative_version"
-    implementation 'org.jetbrains.kotlinx:kotlinx-metadata-jvm:0.8.0'
-
-    // Byteman for runtime (termination) rules injection on the running node
-    // Submission tool allowing to install rules on running nodes
-    slowIntegrationTestCompile "org.jboss.byteman:byteman-submit:4.0.22"
-    // The actual Byteman agent which should only be in the classpath of the out of process nodes
-    slowIntegrationTestCompile "org.jboss.byteman:byteman:4.0.22"
-
-    testImplementation(project(':test-cli'))
-    testImplementation(project(':test-utils'))
-
-    slowIntegrationTestCompile sourceSets.main.output
-    slowIntegrationTestCompile sourceSets.test.output
-    slowIntegrationTestCompile configurations.implementation
-    slowIntegrationTestCompile configurations.testImplementation
-    slowIntegrationTestRuntimeOnly configurations.runtimeOnly
-    slowIntegrationTestRuntimeOnly configurations.testRuntimeOnly
 
+    integrationTestImplementation project(":testing:cordapps:dbfailure:dbfcontracts")
     integrationTestImplementation project(":testing:cordapps:missingmigration")
-
+    // Integration test helpers
-    testImplementation project(':testing:cordapps:dbfailure:dbfworkflows')
+    integrationTestImplementation "de.javakaffee:kryo-serializers:$kryo_serializer_version"
+    integrationTestImplementation "junit:junit:$junit_version"
+    integrationTestImplementation "org.assertj:assertj-core:${assertj_version}"
+    integrationTestImplementation "org.apache.qpid:qpid-jms-client:${protonj_version}"
+    integrationTestImplementation "net.i2p.crypto:eddsa:$eddsa_version"
 
     // used by FinalityFlowErrorHandlingTest
     slowIntegrationTestImplementation project(':testing:cordapps:cashobservers')
+    // Byteman for runtime (termination) rules injection on the running node
+    // Submission tool allowing to install rules on running nodes
+    slowIntegrationTestImplementation "org.jboss.byteman:byteman-submit:4.0.22"
+    // The actual Byteman agent which should only be in the classpath of the out of process nodes
+    slowIntegrationTestImplementation "org.jboss.byteman:byteman:4.0.22"
+
+    corda4_11 "net.corda:corda-finance-contracts:4.11"
 }
 
 tasks.withType(JavaCompile).configureEach {

node/src/integration-test/kotlin/net/corda/node/services/AttachmentLoadingTests.kt

@@ -1,51 +1,42 @@
 package net.corda.node.services
 
 import co.paralleluniverse.fibers.Suspendable
-import net.corda.core.contracts.*
+import net.corda.core.contracts.Amount
-import net.corda.core.flows.*
+import net.corda.core.contracts.TransactionVerificationException
-import net.corda.core.identity.AbstractParty
+import net.corda.core.flows.FinalityFlow
-import net.corda.core.identity.CordaX500Name
+import net.corda.core.flows.FlowException
+import net.corda.core.flows.FlowLogic
+import net.corda.core.flows.FlowSession
+import net.corda.core.flows.InitiatedBy
+import net.corda.core.flows.InitiatingFlow
+import net.corda.core.flows.ReceiveFinalityFlow
+import net.corda.core.flows.StartableByRPC
 import net.corda.core.identity.Party
-import net.corda.core.internal.*
 import net.corda.core.internal.concurrent.transpose
 import net.corda.core.messaging.startFlow
-import net.corda.core.transactions.LedgerTransaction
 import net.corda.core.transactions.TransactionBuilder
+import net.corda.core.utilities.OpaqueBytes
 import net.corda.core.utilities.getOrThrow
 import net.corda.core.utilities.unwrap
-import net.corda.testing.common.internal.checkNotOnClasspath
+import net.corda.finance.DOLLARS
+import net.corda.finance.flows.CashIssueFlow
+import net.corda.finance.workflows.asset.CashUtils
 import net.corda.testing.core.ALICE_NAME
 import net.corda.testing.core.BOB_NAME
 import net.corda.testing.core.DUMMY_NOTARY_NAME
 import net.corda.testing.core.singleIdentity
-import net.corda.testing.driver.DriverDSL
 import net.corda.testing.driver.DriverParameters
+import net.corda.testing.driver.NodeParameters
 import net.corda.testing.driver.driver
 import net.corda.testing.node.NotarySpec
+import net.corda.testing.node.internal.FINANCE_CORDAPPS
+import net.corda.testing.node.internal.FINANCE_WORKFLOWS_CORDAPP
 import net.corda.testing.node.internal.enclosedCordapp
 import org.assertj.core.api.Assertions.assertThatThrownBy
 import org.junit.Test
-import java.net.URL
+import java.util.Currency
-import java.net.URLClassLoader
-import kotlin.io.path.createDirectories
-import kotlin.io.path.div
 
 class AttachmentLoadingTests {
-    private companion object {
-        val isolatedJar: URL = AttachmentLoadingTests::class.java.getResource("/isolated.jar")!!
-        val isolatedClassLoader = URLClassLoader(arrayOf(isolatedJar))
-        val issuanceFlowClass: Class<FlowLogic<StateRef>> = uncheckedCast(loadFromIsolated("net.corda.isolated.workflows.IsolatedIssuanceFlow"))
-
-        init {
-            checkNotOnClasspath("net.corda.isolated.contracts.AnotherDummyContract") {
-                "isolated module cannot be on the classpath as otherwise it will be pulled into the nodes the driver creates and " +
-                        "contaminate the tests. This is a known issue with the driver and we must work around it until it's fixed."
-            }
-        }
-
-        fun loadFromIsolated(className: String): Class<*> = Class.forName(className, false, isolatedClassLoader)
-    }
-
     @Test(timeout=300_000)
 	fun `contracts downloaded from the network are not executed`() {
         driver(DriverParameters(
@@ -53,61 +44,36 @@ class AttachmentLoadingTests {
                 notarySpecs = listOf(NotarySpec(DUMMY_NOTARY_NAME, validating = false)),
                 cordappsForAllNodes = listOf(enclosedCordapp())
         )) {
-            installIsolatedCordapp(ALICE_NAME)
-
             val (alice, bob) = listOf(
-                    startNode(providedName = ALICE_NAME),
+                    startNode(NodeParameters(ALICE_NAME, additionalCordapps = FINANCE_CORDAPPS)),
-                    startNode(providedName = BOB_NAME)
+                    startNode(NodeParameters(BOB_NAME, additionalCordapps = listOf(FINANCE_WORKFLOWS_CORDAPP)))
             ).transpose().getOrThrow()
 
-            val stateRef = alice.rpc.startFlowDynamic(issuanceFlowClass, 1234).returnValue.getOrThrow()
+            alice.rpc.startFlow(::CashIssueFlow, 10.DOLLARS, OpaqueBytes.of(0x00), defaultNotaryIdentity).returnValue.getOrThrow()
 
-            assertThatThrownBy { alice.rpc.startFlow(::ConsumeAndBroadcastFlow, stateRef, bob.nodeInfo.singleIdentity()).returnValue.getOrThrow() }
+            assertThatThrownBy { alice.rpc.startFlow(::ConsumeAndBroadcastFlow, 10.DOLLARS, bob.nodeInfo.singleIdentity()).returnValue.getOrThrow() }
                     // ConsumeAndBroadcastResponderFlow re-throws any non-FlowExceptions with just their class name in the message so that
                     // we can verify here Bob threw the correct exception
                     .hasMessage(TransactionVerificationException.UntrustedAttachmentsException::class.java.name)
         }
     }
 
-    @Test(timeout=300_000)
-	fun `contract is executed if installed locally`() {
-        driver(DriverParameters(
-                startNodesInProcess = false,
-                notarySpecs = listOf(NotarySpec(DUMMY_NOTARY_NAME, validating = false)),
-                cordappsForAllNodes = listOf(enclosedCordapp())
-        )) {
-            installIsolatedCordapp(ALICE_NAME)
-            installIsolatedCordapp(BOB_NAME)
-
-            val (alice, bob) = listOf(
-                    startNode(providedName = ALICE_NAME),
-                    startNode(providedName = BOB_NAME)
-            ).transpose().getOrThrow()
-
-            val stateRef = alice.rpc.startFlowDynamic(issuanceFlowClass, 1234).returnValue.getOrThrow()
-            alice.rpc.startFlow(::ConsumeAndBroadcastFlow, stateRef, bob.nodeInfo.singleIdentity()).returnValue.getOrThrow()
-        }
-    }
-
-    private fun DriverDSL.installIsolatedCordapp(name: CordaX500Name) {
-        val cordappsDir = (baseDirectory(name) / "cordapps").createDirectories()
-        isolatedJar.toPath().copyToDirectory(cordappsDir)
-    }
-
     @InitiatingFlow
     @StartableByRPC
-    class ConsumeAndBroadcastFlow(private val stateRef: StateRef, private val otherSide: Party) : FlowLogic<Unit>() {
+    class ConsumeAndBroadcastFlow(private val amount: Amount<Currency>, private val otherSide: Party) : FlowLogic<Unit>() {
         @Suspendable
         override fun call() {
             val notary = serviceHub.networkMapCache.notaryIdentities[0]
-            val stateAndRef = serviceHub.toStateAndRef<ContractState>(stateRef)
+            val builder = TransactionBuilder(notary)
-            val stx = serviceHub.signInitialTransaction(
+            val (_, keysForSigning) = CashUtils.generateSpend(
-                    TransactionBuilder(notary)
+                    serviceHub,
-                            .addInputState(stateAndRef)
+                    builder,
-                            .addOutputState(ConsumeContract.State())
+                    amount,
-                            .addCommand(Command(ConsumeContract.Cmd, ourIdentity.owningKey))
+                    ourIdentityAndCert,
+                    otherSide,
+                    anonymous = false
             )
-            stx.verify(serviceHub, checkSufficientSignatures = false)
+            val stx = serviceHub.signInitialTransaction(builder, keysForSigning)
             val session = initiateFlow(otherSide)
             subFlow(FinalityFlow(stx, session))
             // It's important we wait on this dummy receive, as otherwise it's possible we miss any errors the other side throws
@@ -129,16 +95,4 @@ class AttachmentLoadingTests {
             otherSide.send("OK")
         }
     }
-
-    class ConsumeContract : Contract {
-        override fun verify(tx: LedgerTransaction) {
-            // Accept everything
-        }
-
-        class State : ContractState {
-            override val participants: List<AbstractParty> get() = emptyList()
-        }
-
-        object Cmd : TypeOnlyCommandData()
-    }
 }

node/src/main/kotlin/net/corda/node/internal/AbstractNode.kt

@@ -79,6 +79,7 @@ import net.corda.node.internal.classloading.requireAnnotation
 import net.corda.node.internal.cordapp.CordappConfigFileProvider
 import net.corda.node.internal.cordapp.CordappProviderImpl
 import net.corda.node.internal.cordapp.JarScanningCordappLoader
+import net.corda.node.internal.cordapp.JarScanningCordappLoader.Companion.LEGACY_CONTRACTS_DIR_NAME
 import net.corda.node.internal.cordapp.VirtualCordapp
 import net.corda.node.internal.rpc.proxies.AuthenticatedRpcOpsProxy
 import net.corda.node.internal.rpc.proxies.ThreadContextAdjustingRpcOpsProxy
@@ -187,6 +188,7 @@ import java.util.function.Consumer
 import javax.persistence.EntityManager
 import javax.sql.DataSource
 import kotlin.io.path.div
+import kotlin.io.path.exists
 
 /**
  * A base node implementation that can be customised either for production (with real implementations that do real
@@ -853,6 +855,7 @@ abstract class AbstractNode<S>(val configuration: NodeConfiguration,
         }
         return JarScanningCordappLoader.fromDirectories(
                 configuration.cordappDirectories,
+                (configuration.baseDirectory / LEGACY_CONTRACTS_DIR_NAME).takeIf { it.exists() },
                 versionInfo,
                 extraCordapps = generatedCordapps,
                 signerKeyFingerprintBlacklist = blacklistedKeys

node/src/main/kotlin/net/corda/node/internal/cordapp/CordappProviderImpl.kt

@@ -6,6 +6,7 @@ import net.corda.core.cordapp.Cordapp
 import net.corda.core.cordapp.CordappContext
 import net.corda.core.flows.FlowLogic
 import net.corda.core.internal.DEPLOYED_CORDAPP_UPLOADER
+import net.corda.core.internal.cordapp.ContractAttachmentWithLegacy
 import net.corda.core.internal.cordapp.CordappImpl
 import net.corda.core.internal.cordapp.CordappProviderInternal
 import net.corda.core.internal.groupByMultipleKeys
@@ -38,6 +39,7 @@ open class CordappProviderImpl(private val cordappLoader: CordappLoader,
 
     fun start() {
         loadContractsIntoAttachmentStore(cordappLoader.cordapps)
+        loadContractsIntoAttachmentStore(cordappLoader.legacyContractCordapps)
         flowToCordapp = makeFlowToCordapp()
         // Load the fix-ups after uploading any new contracts into attachment storage.
         attachmentFixups.load(cordappLoader.appClassLoader)
@@ -56,12 +58,18 @@ open class CordappProviderImpl(private val cordappLoader: CordappLoader,
     }
 
     override fun getContractAttachmentID(contractClassName: ContractClassName): AttachmentId? {
-        // loadContractsIntoAttachmentStore makes sure the jarHash is the attachment ID
+        return cordappLoader.cordapps.findCordapp(contractClassName)
-        return cordappLoader.cordapps.find { contractClassName in it.contractClassNames }?.jarHash
     }
 
-    override fun getContractAttachment(contractClassName: ContractClassName): ContractAttachment? {
+    override fun getContractAttachments(contractClassName: ContractClassName): ContractAttachmentWithLegacy? {
-        return getContractAttachmentID(contractClassName)?.let(::getContractAttachment)
+        val currentAttachmentId = getContractAttachmentID(contractClassName) ?: return null
+        val legacyAttachmentId = cordappLoader.legacyContractCordapps.findCordapp(contractClassName)
+        return ContractAttachmentWithLegacy(getContractAttachment(currentAttachmentId), legacyAttachmentId?.let(::getContractAttachment))
+    }
+
+    private fun List<CordappImpl>.findCordapp(contractClassName: ContractClassName): AttachmentId? {
+        // loadContractsIntoAttachmentStore makes sure the jarHash is the attachment ID
+        return find { contractClassName in it.contractClassNames }?.jarHash
     }
 
     private fun loadContractsIntoAttachmentStore(cordapps: List<CordappImpl>) {

node/src/main/kotlin/net/corda/node/internal/cordapp/JarScanningCordappLoader.kt

@@ -1,6 +1,7 @@
 package net.corda.node.internal.cordapp
 
 import io.github.classgraph.ClassGraph
+import io.github.classgraph.ClassInfo
 import io.github.classgraph.ClassInfoList
 import io.github.classgraph.ScanResult
 import net.corda.common.logging.errorReporting.CordappErrors
@@ -18,13 +19,15 @@ import net.corda.core.internal.JarSignatureCollector
 import net.corda.core.internal.PlatformVersionSwitches
 import net.corda.core.internal.cordapp.CordappImpl
 import net.corda.core.internal.cordapp.CordappImpl.Companion.UNKNOWN_INFO
+import net.corda.core.internal.cordapp.KotlinMetadataVersion
+import net.corda.core.internal.cordapp.LanguageVersion
 import net.corda.core.internal.cordapp.get
 import net.corda.core.internal.flatMapToSet
+import net.corda.core.internal.groupByMultipleKeys
 import net.corda.core.internal.hash
 import net.corda.core.internal.isAbstractClass
 import net.corda.core.internal.loadClassOfType
 import net.corda.core.internal.location
-import net.corda.core.internal.groupByMultipleKeys
 import net.corda.core.internal.mapToSet
 import net.corda.core.internal.notary.NotaryService
 import net.corda.core.internal.notary.SinglePartyNotaryService
@@ -42,6 +45,7 @@ import net.corda.core.serialization.SerializationWhitelist
 import net.corda.core.serialization.SerializeAsToken
 import net.corda.core.utilities.contextLogger
 import net.corda.core.utilities.debug
+import net.corda.core.utilities.trace
 import net.corda.node.VersionInfo
 import net.corda.nodeapi.internal.cordapp.CordappLoader
 import net.corda.nodeapi.internal.coreContractClasses
@@ -50,6 +54,7 @@ import java.lang.reflect.Modifier
 import java.net.URLClassLoader
 import java.nio.file.Path
 import java.util.ServiceLoader
+import java.util.TreeSet
 import java.util.jar.JarInputStream
 import java.util.jar.Manifest
 import kotlin.io.path.absolutePathString
@@ -57,27 +62,35 @@ import kotlin.io.path.exists
 import kotlin.io.path.inputStream
 import kotlin.io.path.isSameFileAs
 import kotlin.io.path.listDirectoryEntries
+import kotlin.io.path.useDirectoryEntries
 import kotlin.reflect.KClass
+import kotlin.reflect.KProperty1
 
 /**
  * Handles CorDapp loading and classpath scanning of CorDapp JARs
  *
  * @property cordappJars The classpath of cordapp JARs
+ * @property legacyContractJars Legacy contract CorDapps (4.11 or earlier) needed for backwards compatibility with 4.11 nodes.
  */
 @Suppress("TooManyFunctions")
 class JarScanningCordappLoader(private val cordappJars: Set<Path>,
+                               private val legacyContractJars: Set<Path> = emptySet(),
                                private val versionInfo: VersionInfo = VersionInfo.UNKNOWN,
                                private val extraCordapps: List<CordappImpl> = emptyList(),
                                private val signerKeyFingerprintBlacklist: List<SecureHash> = emptyList()) : CordappLoader {
     companion object {
         private val logger = contextLogger()
 
+        const val LEGACY_CONTRACTS_DIR_NAME = "legacy-contracts"
+
         /**
          * Creates a CordappLoader from multiple directories.
          *
          * @param cordappDirs Directories used to scan for CorDapp JARs.
+         * @param legacyContractsDir Directory containing legacy contract CorDapps (4.11 or earlier).
          */
         fun fromDirectories(cordappDirs: Collection<Path>,
+                            legacyContractsDir: Path? = null,
                             versionInfo: VersionInfo = VersionInfo.UNKNOWN,
                             extraCordapps: List<CordappImpl> = emptyList(),
                             signerKeyFingerprintBlacklist: List<SecureHash> = emptyList()): JarScanningCordappLoader {
@@ -86,12 +99,14 @@ class JarScanningCordappLoader(private val cordappJars: Set<Path>,
                     .asSequence()
                     .flatMap { if (it.exists()) it.listDirectoryEntries("*.jar") else emptyList() }
                     .toSet()
-            return JarScanningCordappLoader(cordappJars, versionInfo, extraCordapps, signerKeyFingerprintBlacklist)
+            val legacyContractJars = legacyContractsDir?.useDirectoryEntries("*.jar") { it.toSet() } ?: emptySet()
+            return JarScanningCordappLoader(cordappJars, legacyContractJars, versionInfo, extraCordapps, signerKeyFingerprintBlacklist)
         }
     }
 
     init {
         logger.debug { "cordappJars: $cordappJars" }
+        logger.debug { "legacyContractJars: $legacyContractJars" }
     }
 
     override val appClassLoader = URLClassLoader(cordappJars.stream().map { it.toUri().toURL() }.toTypedArray(), javaClass.classLoader)
@@ -99,21 +114,46 @@ class JarScanningCordappLoader(private val cordappJars: Set<Path>,
     private val internal by lazy(::InternalHolder)
 
     override val cordapps: List<CordappImpl>
-        get() = internal.cordapps
+        get() = internal.nonLegacyCordapps
+
+    override val legacyContractCordapps: List<CordappImpl>
+        get() = internal.legacyContractCordapps
 
     override fun close() = appClassLoader.close()
 
     private inner class InternalHolder {
-        val cordapps = cordappJars.mapTo(ArrayList(), ::scanCordapp)
+        val nonLegacyCordapps = cordappJars.mapTo(ArrayList(), ::scanCordapp)
+        val legacyContractCordapps = legacyContractJars.map(::scanCordapp)
 
         init {
-            checkInvalidCordapps()
+            commonChecks(nonLegacyCordapps, LanguageVersion::isNonLegacyCompatible)
-            checkDuplicateCordapps()
+            nonLegacyCordapps += extraCordapps
-            checkContractOverlap()
+            if (legacyContractCordapps.isNotEmpty()) {
-            cordapps += extraCordapps
+                commonChecks(legacyContractCordapps, LanguageVersion::isLegacyCompatible)
+                checkLegacyContracts()
+            }
         }
 
-        private fun checkInvalidCordapps() {
+        private fun commonChecks(cordapps: List<CordappImpl>, compatibilityProperty: KProperty1<LanguageVersion, Boolean>) {
+            for (cordapp in cordapps) {
+                check(compatibilityProperty(cordapp.languageVersion)) {
+                    val isLegacyCompatibleCheck = compatibilityProperty == LanguageVersion::isLegacyCompatible
+                    val msg = when {
+                        isLegacyCompatibleCheck -> "not legacy; please remove or place it in the node's CorDapps directory."
+                        cordapp.contractClassNames.isEmpty() -> "legacy (should be 4.12 or later)"
+                        else -> "legacy contracts; please place it in the node's '$LEGACY_CONTRACTS_DIR_NAME' directory."
+                    }
+                    "CorDapp ${cordapp.jarFile} is $msg"
+                }
+            }
+            checkInvalidCordapps(cordapps)
+            checkDuplicateCordapps(cordapps)
+            // The same contract may occur in both 4.11 and 4.12 CorDapps for ledger compatibility, so we only check for overlap within each
+            // compatibility group
+            checkContractOverlap(cordapps)
+        }
+
+        private fun checkInvalidCordapps(cordapps: List<CordappImpl>) {
             val invalidCordapps = LinkedHashMap<String, CordappImpl>()
 
             for (cordapp in cordapps) {
@@ -139,7 +179,7 @@ class JarScanningCordappLoader(private val cordappJars: Set<Path>,
             }
         }
 
-        private fun checkDuplicateCordapps() {
+        private fun checkDuplicateCordapps(cordapps: List<CordappImpl>) {
             for (group in cordapps.groupBy { it.jarHash }.values) {
                 if (group.size > 1) {
                     throw DuplicateCordappsInstalledException(group[0], group.drop(1))
@@ -147,12 +187,38 @@ class JarScanningCordappLoader(private val cordappJars: Set<Path>,
             }
         }
 
-        private fun checkContractOverlap() {
+        private fun checkContractOverlap(cordapps: List<CordappImpl>) {
             cordapps.groupByMultipleKeys(CordappImpl::contractClassNames) { contract, cordapp1, cordapp2 ->
                 throw IllegalStateException("Contract $contract occuring in multiple CorDapps (${cordapp1.name}, ${cordapp2.name}). " +
                         "Please remove the previous version when upgrading to a new version.")
             }
         }
+
+        private fun checkLegacyContracts() {
+            for (legacyCordapp in legacyContractCordapps) {
+                if (legacyCordapp.contractClassNames.isEmpty()) continue
+                logger.debug { "Contracts CorDapp ${legacyCordapp.name} is legacy (4.11 or older), searching for corresponding 4.12+ contracts" }
+                for (legacyContract in legacyCordapp.contractClassNames) {
+                    val newerCordapp = nonLegacyCordapps.find { legacyContract in it.contractClassNames }
+                    checkNotNull(newerCordapp) {
+                        "Contract $legacyContract in legacy CorDapp (4.11 or older) '${legacyCordapp.jarFile}' does not have a " +
+                                "corresponding newer version (4.12 or later). Please add this corresponding CorDapp or remove the legacy one."
+                    }
+                    check(newerCordapp.contractVersionId > legacyCordapp.contractVersionId) {
+                        "Newer contract CorDapp '${newerCordapp.jarFile}' does not have a higher version number " +
+                                "(${newerCordapp.contractVersionId}) compared to corresponding legacy contract CorDapp " +
+                                "'${legacyCordapp.jarFile}' (${legacyCordapp.contractVersionId})"
+                    }
+                }
+            }
+        }
+
+        private val CordappImpl.contractVersionId: Int
+            get() = when (val info = info) {
+                is Cordapp.Info.Contract -> info.versionId
+                is Cordapp.Info.ContractAndWorkflow -> info.contract.versionId
+                else -> 1
+            }
     }
 
     private fun ScanResult.toCordapp(path: Path): CordappImpl {
@@ -160,6 +226,8 @@ class JarScanningCordappLoader(private val cordappJars: Set<Path>,
         val info = parseCordappInfo(manifest, CordappImpl.jarName(path))
         val minPlatformVersion = manifest?.get(CordappImpl.MIN_PLATFORM_VERSION)?.toIntOrNull() ?: 1
         val targetPlatformVersion = manifest?.get(CordappImpl.TARGET_PLATFORM_VERSION)?.toIntOrNull() ?: minPlatformVersion
+        val languageVersion = determineLanguageVersion(path)
+        logger.debug { "$path: $languageVersion" }
         return CordappImpl(
                 path,
                 findContractClassNames(this),
@@ -177,6 +245,7 @@ class JarScanningCordappLoader(private val cordappJars: Set<Path>,
                 info,
                 minPlatformVersion,
                 targetPlatformVersion,
+                languageVersion = languageVersion,
                 notaryService = findNotaryService(this),
                 explicitCordappClasses = findAllCordappClasses(this)
         )
@@ -360,6 +429,36 @@ class JarScanningCordappLoader(private val cordappJars: Set<Path>,
     private fun <T : Any> ClassInfoList.getAllConcreteClasses(type: KClass<T>): List<Class<out T>> {
         return mapNotNull { loadClass(it.name, type)?.takeUnless(Class<*>::isAbstractClass) }
     }
+
+    private fun ScanResult.determineLanguageVersion(cordappJar: Path): LanguageVersion {
+        val allClasses = allClassesAsMap.values
+        if (allClasses.isEmpty()) {
+            return LanguageVersion.Data
+        }
+        val classFileMajorVersion = allClasses.maxOf { it.classfileMajorVersion }
+        val kotlinMetadataVersion = allClasses
+                .mapNotNullTo(TreeSet()) { it.kotlinMetadataVersion() }
+                .let { kotlinMetadataVersions ->
+                    // If there's more than one minor version of Kotlin
+                    if (kotlinMetadataVersions.size > 1 && kotlinMetadataVersions.mapToSet { it.copy(patch = 0) }.size > 1) {
+                        logger.warn("CorDapp $cordappJar comprised of multiple Kotlin versions (kotlinMetadataVersions=$kotlinMetadataVersions). " +
+                                "This may cause compatibility issues.")
+                    }
+                    kotlinMetadataVersions.takeIf { it.isNotEmpty() }?.last()
+                }
+        try {
+            return LanguageVersion.Bytecode(classFileMajorVersion, kotlinMetadataVersion)
+        } catch (e: IllegalArgumentException) {
+            throw IllegalStateException("Unable to load CorDapp $cordappJar: ${e.message}")
+        }
+    }
+
+    private fun ClassInfo.kotlinMetadataVersion(): KotlinMetadataVersion? {
+        val kotlinMetadata = getAnnotationInfo(Metadata::class.java) ?: return null
+        val kotlinMetadataVersion = KotlinMetadataVersion.from(kotlinMetadata.parameterValues.get("mv").value as IntArray)
+        logger.trace { "$name: $kotlinMetadataVersion" }
+        return kotlinMetadataVersion
+    }
 }
 
 /**

node/src/main/kotlin/net/corda/node/services/persistence/NodeAttachmentService.kt

@@ -6,8 +6,6 @@ import com.google.common.hash.HashCode
 import com.google.common.hash.Hashing
 import com.google.common.hash.HashingInputStream
 import com.google.common.io.CountingInputStream
-import kotlinx.metadata.jvm.KotlinModuleMetadata
-import kotlinx.metadata.jvm.UnstableMetadataApi
 import net.corda.core.CordaRuntimeException
 import net.corda.core.contracts.Attachment
 import net.corda.core.contracts.ContractAttachment
@@ -18,7 +16,6 @@ import net.corda.core.internal.AbstractAttachment
 import net.corda.core.internal.DEPLOYED_CORDAPP_UPLOADER
 import net.corda.core.internal.FetchAttachmentsFlow
 import net.corda.core.internal.JarSignatureCollector
-import net.corda.core.internal.InternalAttachment
 import net.corda.core.internal.NamedCacheFactory
 import net.corda.core.internal.P2P_UPLOADER
 import net.corda.core.internal.RPC_UPLOADER
@@ -28,7 +25,6 @@ import net.corda.core.internal.Version
 import net.corda.core.internal.VisibleForTesting
 import net.corda.core.internal.cordapp.CordappImpl.Companion.CORDAPP_CONTRACT_VERSION
 import net.corda.core.internal.cordapp.CordappImpl.Companion.DEFAULT_CORDAPP_VERSION
-import net.corda.core.internal.entries
 import net.corda.core.internal.isUploaderTrusted
 import net.corda.core.internal.readFully
 import net.corda.core.internal.utilities.ZipBombDetector
@@ -266,8 +262,7 @@ class NodeAttachmentService @JvmOverloads constructor(
             private val checkOnLoad: Boolean,
             uploader: String?,
             override val signerKeys: List<PublicKey>,
-            override val kotlinMetadataVersion: String?
+    ) : AbstractAttachment(dataLoader, uploader), SerializeAsToken {
-    ) : AbstractAttachment(dataLoader, uploader), InternalAttachment, SerializeAsToken {
 
         override fun open(): InputStream {
             val stream = super.open()
@@ -280,7 +275,6 @@ class NodeAttachmentService @JvmOverloads constructor(
                 private val checkOnLoad: Boolean,
                 private val uploader: String?,
                 private val signerKeys: List<PublicKey>,
-                private val kotlinMetadataVersion: String?
         ) : SerializationToken {
             override fun fromToken(context: SerializeAsTokenContext) = AttachmentImpl(
                     id,
@@ -288,12 +282,10 @@ class NodeAttachmentService @JvmOverloads constructor(
                     checkOnLoad,
                     uploader,
                     signerKeys,
-                    kotlinMetadataVersion
             )
         }
 
-        override fun toToken(context: SerializeAsTokenContext) =
+        override fun toToken(context: SerializeAsTokenContext) = Token(id, checkOnLoad, uploader, signerKeys)
-            Token(id, checkOnLoad, uploader, signerKeys, kotlinMetadataVersion)
     }
 
     private val attachmentContentCache = NonInvalidatingWeightBasedCache(
@@ -311,24 +303,13 @@ class NodeAttachmentService @JvmOverloads constructor(
         }
     }
 
-    @OptIn(UnstableMetadataApi::class)
     private fun createAttachmentFromDatabase(attachment: DBAttachment): Attachment {
-        // TODO Cache this as a column in the database
-        val jis = JarInputStream(attachment.content.inputStream())
-        val kotlinMetadataVersions = jis.entries()
-                .filter { it.name.endsWith(".kotlin_module") }
-                .map { KotlinModuleMetadata.read(jis.readAllBytes()).version }
-                .toSortedSet()
-        if (kotlinMetadataVersions.size > 1) {
-            log.warn("Attachment ${attachment.attId} seems to be comprised of multiple Kotlin versions: $kotlinMetadataVersions")
-        }
         val attachmentImpl = AttachmentImpl(
                 id = SecureHash.create(attachment.attId),
                 dataLoader = { attachment.content },
                 checkOnLoad = checkAttachmentsOnLoad,
                 uploader = attachment.uploader,
-                signerKeys = attachment.signers?.toList() ?: emptyList(),
+                signerKeys = attachment.signers?.toList() ?: emptyList()
-                kotlinMetadataVersion = kotlinMetadataVersions.takeIf { it.isNotEmpty() }?.last()?.toString()
         )
         val contracts = attachment.contractClassNames
         return if (!contracts.isNullOrEmpty()) {
@@ -376,14 +357,6 @@ class NodeAttachmentService @JvmOverloads constructor(
         return import(jar, uploader, filename)
     }
 
-    override fun privilegedImportOrGetAttachment(jar: InputStream, uploader: String, filename: String?): AttachmentId {
-        return try {
-            import(jar, uploader, filename)
-        } catch (faee: FileAlreadyExistsException) {
-            AttachmentId.create(faee.message!!)
-        }
-    }
-
     override fun hasAttachment(attachmentId: AttachmentId): Boolean = database.transaction {
         currentDBSession().find(DBAttachment::class.java, attachmentId.toString()) != null
     }

node/src/main/kotlin/net/corda/node/verification/ExternalVerifierHandleImpl.kt

@@ -195,7 +195,7 @@ class ExternalVerifierHandleImpl(
                     "${server.localPort}",
                     log.level.name.lowercase()
             )
-            log.debug { "Verifier command: $command" }
+            log.debug { "External verifier command: $command" }
             val logsDirectory = (baseDirectory / "logs").createDirectories()
             verifierProcess = ProcessBuilder(command)
                     .redirectOutput(Redirect.appendTo((logsDirectory / "verifier-stdout.log").toFile()))

node/src/test/kotlin/net/corda/node/internal/NodeH2SecurityTests.kt

@@ -1,9 +1,5 @@
 package net.corda.node.internal
 
-import org.mockito.kotlin.atLeast
-import org.mockito.kotlin.mock
-import org.mockito.kotlin.verify
-import org.mockito.kotlin.whenever
 import net.corda.core.identity.CordaX500Name
 import net.corda.core.serialization.SerializeAsToken
 import net.corda.core.utilities.NetworkHostAndPort
@@ -20,12 +16,17 @@ import net.corda.nodeapi.internal.persistence.DatabaseConfig
 import org.assertj.core.api.Assertions.assertThat
 import org.h2.tools.Server
 import org.junit.Test
+import org.mockito.kotlin.atLeast
+import org.mockito.kotlin.mock
+import org.mockito.kotlin.verify
+import org.mockito.kotlin.whenever
 import java.net.InetAddress
 import java.sql.Connection
 import java.sql.DatabaseMetaData
-import java.util.*
+import java.util.Properties
 import java.util.concurrent.ExecutorService
 import javax.sql.DataSource
+import kotlin.io.path.Path
 import kotlin.test.assertFailsWith
 
 class NodeH2SecurityTests {
@@ -133,13 +134,13 @@ class NodeH2SecurityTests {
     init {
         whenever(config.database).thenReturn(database)
         whenever(config.dataSourceProperties).thenReturn(hikaryProperties)
-        whenever(config.baseDirectory).thenReturn(mock())
+        whenever(config.baseDirectory).thenReturn(Path("."))
         whenever(config.effectiveH2Settings).thenAnswer { NodeH2Settings(address) }
         whenever(config.telemetry).thenReturn(mock())
         whenever(config.myLegalName).thenReturn(CordaX500Name(null, "client-${address.toString()}", "Corda", "London", null, "GB"))
     }
 
-    private inner class MockNode: Node(config, VersionInfo.UNKNOWN, false) {
+    private inner class MockNode : Node(config, VersionInfo.UNKNOWN, false) {
         fun startDb() = startDatabase()
 
         override fun makeMessagingService(): MessagingService {

node/src/test/kotlin/net/corda/node/internal/cordapp/CordappProviderImplTests.kt

@@ -36,8 +36,9 @@ import kotlin.test.assertFailsWith
 
 class CordappProviderImplTests {
     private companion object {
-        val financeContractsJar = this::class.java.getResource("/corda-finance-contracts.jar")!!.toPath()
+        val currentFinanceContractsJar = this::class.java.getResource("/corda-finance-contracts.jar")!!.toPath()
-        val financeWorkflowsJar = this::class.java.getResource("/corda-finance-workflows.jar")!!.toPath()
+        val currentFinanceWorkflowsJar = this::class.java.getResource("/corda-finance-workflows.jar")!!.toPath()
+        val legacyFinanceContractsJar = this::class.java.getResource("/corda-finance-contracts-4.11.jar")!!.toPath()
 
         @JvmField
         val ID1 = AttachmentId.randomSHA256()
@@ -83,7 +84,7 @@ class CordappProviderImplTests {
 
     @Test(timeout=300_000)
 	fun `test that we find a cordapp class that is loaded into the store`() {
-        val provider = newCordappProvider(setOf(financeContractsJar))
+        val provider = newCordappProvider(setOf(currentFinanceContractsJar))
 
         val expected = provider.cordapps.first()
         val actual = provider.getCordappForClass(Cash::class.java.name)
@@ -94,7 +95,7 @@ class CordappProviderImplTests {
 
     @Test(timeout=300_000)
 	fun `test that we find an attachment for a cordapp contract class`() {
-        val provider = newCordappProvider(setOf(financeContractsJar))
+        val provider = newCordappProvider(setOf(currentFinanceContractsJar))
         val expected = provider.getAppContext(provider.cordapps.first()).attachmentId
         val actual = provider.getContractAttachmentID(Cash::class.java.name)
 
@@ -106,7 +107,7 @@ class CordappProviderImplTests {
     fun `test cordapp configuration`() {
         val configProvider = MockCordappConfigProvider()
         configProvider.cordappConfigs["corda-finance-contracts"] = ConfigFactory.parseString("key=value")
-        val provider = newCordappProvider(setOf(financeContractsJar), cordappConfigProvider = configProvider)
+        val provider = newCordappProvider(setOf(currentFinanceContractsJar), cordappConfigProvider = configProvider)
 
         val expected = provider.getAppContext(provider.cordapps.first()).config
 
@@ -115,23 +116,33 @@ class CordappProviderImplTests {
 
     @Test(timeout=300_000)
     fun getCordappForFlow() {
-        val provider = newCordappProvider(setOf(financeWorkflowsJar))
+        val provider = newCordappProvider(setOf(currentFinanceWorkflowsJar))
         val cashIssueFlow = CashIssueFlow(10.DOLLARS, OpaqueBytes.of(0x00), TestIdentity(ALICE_NAME).party)
-        assertThat(provider.getCordappForFlow(cashIssueFlow)?.jarPath?.toPath()).isEqualTo(financeWorkflowsJar)
+        assertThat(provider.getCordappForFlow(cashIssueFlow)?.jarPath?.toPath()).isEqualTo(currentFinanceWorkflowsJar)
     }
 
     @Test(timeout=300_000)
     fun `does not load the same flow across different CorDapps`() {
         val unsignedJar = tempFolder.newFile("duplicate.jar").toPath()
-        financeWorkflowsJar.copyTo(unsignedJar, overwrite = true)
+        currentFinanceWorkflowsJar.copyTo(unsignedJar, overwrite = true)
         // We just need to change the file's hash and thus avoid the duplicate CorDapp check
         unsignedJar.unsignJar()
-        assertThat(unsignedJar.hash).isNotEqualTo(financeWorkflowsJar.hash)
+        assertThat(unsignedJar.hash).isNotEqualTo(currentFinanceWorkflowsJar.hash)
         assertFailsWith<MultipleCordappsForFlowException> {
-            newCordappProvider(setOf(financeWorkflowsJar, unsignedJar))
+            newCordappProvider(setOf(currentFinanceWorkflowsJar, unsignedJar))
         }
     }
 
+    @Test(timeout=300_000)
+    fun `retrieving legacy attachment for contract`() {
+        val provider = newCordappProvider(setOf(currentFinanceContractsJar), setOf(legacyFinanceContractsJar))
+        val (current, legacy) = provider.getContractAttachments(Cash::class.java.name)!!
+        assertThat(current.id).isEqualTo(currentFinanceContractsJar.hash)
+        assertThat(legacy?.id).isEqualTo(legacyFinanceContractsJar.hash)
+        // getContractAttachmentID should always return the non-legacy attachment ID
+        assertThat(provider.getContractAttachmentID(Cash::class.java.name)).isEqualTo(currentFinanceContractsJar.hash)
+    }
+
     @Test(timeout=300_000)
 	fun `test fixup rule that adds attachment`() {
         val fixupJar = File.createTempFile("fixup", ".jar")
@@ -220,8 +231,10 @@ class CordappProviderImplTests {
         return this
     }
 
-    private fun newCordappProvider(cordappJars: Set<Path>, cordappConfigProvider: CordappConfigProvider = stubConfigProvider): CordappProviderImpl {
+    private fun newCordappProvider(cordappJars: Set<Path>,
-        val loader = JarScanningCordappLoader(cordappJars)
+                                   legacyContractJars: Set<Path> = emptySet(),
+                                   cordappConfigProvider: CordappConfigProvider = stubConfigProvider): CordappProviderImpl {
+        val loader = JarScanningCordappLoader(cordappJars, legacyContractJars)
         return CordappProviderImpl(loader, cordappConfigProvider, attachmentStore).apply { start() }
     }
 }

node/src/test/kotlin/net/corda/node/internal/cordapp/JarScanningCordappLoaderTest.kt

@@ -27,6 +27,7 @@ import net.corda.testing.core.internal.ContractJarTestUtils.makeTestContractJar
 import net.corda.testing.core.internal.JarSignatureTestUtils.generateKey
 import net.corda.testing.core.internal.JarSignatureTestUtils.getJarSigners
 import net.corda.testing.core.internal.JarSignatureTestUtils.signJar
+import net.corda.testing.core.internal.JarSignatureTestUtils.unsignJar
 import net.corda.testing.internal.LogHelper
 import net.corda.testing.node.internal.cordappWithPackages
 import org.assertj.core.api.Assertions.assertThat
@@ -69,8 +70,9 @@ class DummyRPCFlow : FlowLogic<Unit>() {
 
 class JarScanningCordappLoaderTest {
     private companion object {
-        val financeContractsJar = this::class.java.getResource("/corda-finance-contracts.jar")!!.toPath()
+        val legacyFinanceContractsJar = this::class.java.getResource("/corda-finance-contracts-4.11.jar")!!.toPath()
-        val financeWorkflowsJar = this::class.java.getResource("/corda-finance-workflows.jar")!!.toPath()
+        val currentFinanceContractsJar = this::class.java.getResource("/corda-finance-contracts.jar")!!.toPath()
+        val currentFinanceWorkflowsJar = this::class.java.getResource("/corda-finance-workflows.jar")!!.toPath()
 
         init {
             LogHelper.setLevel(JarScanningCordappLoaderTest::class)
@@ -90,20 +92,20 @@ class JarScanningCordappLoaderTest {
 
     @Test(timeout=300_000)
     fun `constructed CordappImpls contains the right classes`() {
-        val loader = JarScanningCordappLoader(setOf(financeContractsJar, financeWorkflowsJar))
+        val loader = JarScanningCordappLoader(setOf(currentFinanceContractsJar, currentFinanceWorkflowsJar))
         val (contractsCordapp, workflowsCordapp) = loader.cordapps
 
         assertThat(contractsCordapp.contractClassNames).contains(Cash::class.java.name, CommercialPaper::class.java.name)
         assertThat(contractsCordapp.customSchemas).contains(CashSchemaV1, CommercialPaperSchemaV1)
         assertThat(contractsCordapp.info).isInstanceOf(Cordapp.Info.Contract::class.java)
         assertThat(contractsCordapp.allFlows).isEmpty()
-        assertThat(contractsCordapp.jarFile).isEqualTo(financeContractsJar)
+        assertThat(contractsCordapp.jarFile).isEqualTo(currentFinanceContractsJar)
 
         assertThat(workflowsCordapp.allFlows).contains(CashIssueFlow::class.java, CashPaymentFlow::class.java)
         assertThat(workflowsCordapp.services).contains(ConfigHolder::class.java)
         assertThat(workflowsCordapp.info).isInstanceOf(Cordapp.Info.Workflow::class.java)
         assertThat(workflowsCordapp.contractClassNames).isEmpty()
-        assertThat(workflowsCordapp.jarFile).isEqualTo(financeWorkflowsJar)
+        assertThat(workflowsCordapp.jarFile).isEqualTo(currentFinanceWorkflowsJar)
 
         for (actualCordapp in loader.cordapps) {
             assertThat(actualCordapp.cordappClasses)
@@ -196,22 +198,32 @@ class JarScanningCordappLoaderTest {
 
     @Test(timeout=300_000)
     fun `loads app signed by allowed certificate`() {
-        val loader = JarScanningCordappLoader(setOf(financeContractsJar), signerKeyFingerprintBlacklist = emptyList())
+        val loader = JarScanningCordappLoader(setOf(currentFinanceContractsJar), signerKeyFingerprintBlacklist = emptyList())
         assertThat(loader.cordapps).hasSize(1)
     }
 
     @Test(timeout = 300_000)
 	fun `does not load app signed by blacklisted certificate`() {
-        val cordappLoader = JarScanningCordappLoader(setOf(financeContractsJar), signerKeyFingerprintBlacklist = DEV_PUB_KEY_HASHES)
+        val cordappLoader = JarScanningCordappLoader(setOf(currentFinanceContractsJar), signerKeyFingerprintBlacklist = DEV_PUB_KEY_HASHES)
         assertThatExceptionOfType(InvalidCordappException::class.java).isThrownBy {
             cordappLoader.cordapps
         }
     }
 
+    @Test(timeout=300_000)
+    fun `does not load legacy contract CorDapp signed by blacklisted certificate`() {
+        val unsignedJar = currentFinanceContractsJar.duplicate { unsignJar() }
+        val loader = JarScanningCordappLoader(setOf(unsignedJar), setOf(legacyFinanceContractsJar), signerKeyFingerprintBlacklist = DEV_PUB_KEY_HASHES)
+        assertThatExceptionOfType(InvalidCordappException::class.java)
+                .isThrownBy { loader.cordapps }
+                .withMessageContaining("Corresponding contracts are signed by blacklisted key(s)")
+                .withMessageContaining(legacyFinanceContractsJar.name)
+    }
+
     @Test(timeout=300_000)
     fun `does not load duplicate CorDapps`() {
-        val duplicateJar = financeWorkflowsJar.duplicate()
+        val duplicateJar = currentFinanceWorkflowsJar.duplicate()
-        val loader = JarScanningCordappLoader(setOf(financeWorkflowsJar, duplicateJar))
+        val loader = JarScanningCordappLoader(setOf(currentFinanceWorkflowsJar, duplicateJar))
         assertFailsWith<DuplicateCordappsInstalledException> {
             loader.cordapps
         }
@@ -235,7 +247,7 @@ class JarScanningCordappLoaderTest {
 
     @Test(timeout=300_000)
     fun `loads app signed by both allowed and non-blacklisted certificate`() {
-        val jar = financeWorkflowsJar.duplicate {
+        val jar = currentFinanceWorkflowsJar.duplicate {
             tempFolder.root.toPath().generateKey("testAlias", "testPassword", ALICE_NAME.toString())
             tempFolder.root.toPath().signJar(absolutePathString(), "testAlias", "testPassword")
         }
@@ -244,6 +256,38 @@ class JarScanningCordappLoaderTest {
         assertThat(loader.cordapps).hasSize(1)
     }
 
+    @Test(timeout=300_000)
+    fun `loads both legacy and current versions of the same contracts CorDapp`() {
+        val loader = JarScanningCordappLoader(setOf(currentFinanceContractsJar), setOf(legacyFinanceContractsJar))
+        assertThat(loader.cordapps).hasSize(1)  // Legacy contract CorDapps are not part of the main list
+        assertThat(loader.legacyContractCordapps).hasSize(1)
+        assertThat(loader.legacyContractCordapps.single().jarFile).isEqualTo(legacyFinanceContractsJar)
+    }
+
+    @Test(timeout=300_000)
+    fun `does not load legacy contracts CorDapp without the corresponding current version`() {
+        val loader = JarScanningCordappLoader(setOf(currentFinanceWorkflowsJar), setOf(legacyFinanceContractsJar))
+        assertThatIllegalStateException()
+                .isThrownBy { loader.legacyContractCordapps }
+                .withMessageContaining("does not have a corresponding newer version (4.12 or later). Please add this corresponding CorDapp or remove the legacy one.")
+    }
+
+    @Test(timeout=300_000)
+    fun `checks if legacy contract CorDapp is actually legacy`() {
+        val loader = JarScanningCordappLoader(setOf(currentFinanceContractsJar), setOf(currentFinanceContractsJar))
+        assertThatIllegalStateException()
+                .isThrownBy { loader.legacyContractCordapps }
+                .withMessageContaining("${currentFinanceContractsJar.name} is not legacy; please remove or place it in the node's CorDapps directory.")
+    }
+
+    @Test(timeout=300_000)
+    fun `does not load if legacy CorDapp present in general list`() {
+        val loader = JarScanningCordappLoader(setOf(legacyFinanceContractsJar))
+        assertThatIllegalStateException()
+                .isThrownBy { loader.cordapps }
+                .withMessageContaining("${legacyFinanceContractsJar.name} is legacy contracts; please place it in the node's 'legacy-contracts' directory.")
+    }
+
     private inline fun Path.duplicate(name: String = "duplicate.jar", modify: Path.() -> Unit = { }): Path {
         val copy = tempFolder.newFile(name).toPath()
         copyTo(copy, overwrite = true)
@@ -252,7 +296,7 @@ class JarScanningCordappLoaderTest {
     }
 
     private fun minAndTargetCordapp(minVersion: Int?, targetVersion: Int?): Path {
-        return financeWorkflowsJar.duplicate {
+        return currentFinanceWorkflowsJar.duplicate {
             modifyJarManifest { manifest ->
                 manifest.setOrDeleteAttribute("Min-Platform-Version", minVersion?.toString())
                 manifest.setOrDeleteAttribute("Target-Platform-Version", targetVersion?.toString())

testing/smoke-test-utils/src/main/kotlin/net/corda/smoketesting/NodeParams.kt

@@ -18,6 +18,7 @@ class NodeParams @JvmOverloads constructor(
         val rpcAdminPort: Int,
         val users: List<User>,
         val cordappJars: List<Path> = emptyList(),
+        val legacyContractJars: List<Path> = emptyList(),
         val jarDirs: List<Path> = emptyList(),
         val clientRpcConfig: CordaRPCClientConfiguration = CordaRPCClientConfiguration.DEFAULT,
         val devMode: Boolean = true,

testing/smoke-test-utils/src/main/kotlin/net/corda/smoketesting/NodeProcess.kt

@@ -138,6 +138,10 @@ class NodeProcess(
             log.info("Node directory: {}", nodeDir)
             val cordappsDir = (nodeDir / CORDAPPS_DIR_NAME).createDirectory()
             params.cordappJars.forEach { it.copyToDirectory(cordappsDir) }
+            if (params.legacyContractJars.isNotEmpty()) {
+                val legacyContractsDir = (nodeDir / "legacy-contracts").createDirectories()
+                params.legacyContractJars.forEach { it.copyToDirectory(legacyContractsDir) }
+            }
             (nodeDir / "node.conf").writeText(params.createNodeConfig(isNotary))
             networkParametersCopier.install(nodeDir)
             nodeInfoFilesCopier.addConfig(nodeDir)

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

@@ -7,7 +7,6 @@ import net.corda.core.contracts.StateRef
 import net.corda.core.contracts.TimeWindow
 import net.corda.core.contracts.TransactionState
 import net.corda.core.crypto.Crypto
-import net.corda.core.crypto.Crypto.generateKeyPair
 import net.corda.core.crypto.DigestService
 import net.corda.core.crypto.SecureHash
 import net.corda.core.identity.AbstractParty
@@ -49,13 +48,11 @@ import net.corda.testing.core.ALICE_NAME
 import net.corda.testing.core.SerializationEnvironmentRule
 import net.corda.testing.core.TestIdentity
 import java.io.ByteArrayOutputStream
-import java.io.IOException
-import java.net.ServerSocket
 import java.nio.file.Path
 import java.security.KeyPair
 import java.security.cert.X509CRL
 import java.security.cert.X509Certificate
-import java.util.*
+import java.util.Properties
 import java.util.jar.JarOutputStream
 import java.util.jar.Manifest
 import java.util.zip.ZipEntry
@@ -111,7 +108,7 @@ fun createDevIntermediateCaCertPath(
  */
 fun createDevNodeCaCertPath(
         legalName: CordaX500Name,
-        nodeKeyPair: KeyPair = generateKeyPair(X509Utilities.DEFAULT_TLS_SIGNATURE_SCHEME),
+        nodeKeyPair: KeyPair = Crypto.generateKeyPair(X509Utilities.DEFAULT_TLS_SIGNATURE_SCHEME),
         rootCaName: X500Principal = defaultRootCaName,
         intermediateCaName: X500Principal = defaultIntermediateCaName
 ): Triple<CertificateAndKeyPair, CertificateAndKeyPair, CertificateAndKeyPair> {
@@ -156,7 +153,6 @@ fun fixedCrlSource(crls: Set<X509CRL>): CrlSource {
     }
 }
 
-/** This is the same as the deprecated [WireTransaction] c'tor but avoids the deprecation warning. */
 @SuppressWarnings("LongParameterList")
 fun createWireTransaction(inputs: List<StateRef>,
                           attachments: List<SecureHash>,
@@ -164,9 +160,10 @@ fun createWireTransaction(inputs: List<StateRef>,
                           commands: List<Command<*>>,
                           notary: Party?,
                           timeWindow: TimeWindow?,
+                          legacyAttachments: List<SecureHash> = emptyList(),
                           privacySalt: PrivacySalt = PrivacySalt(),
                           digestService: DigestService = DigestService.default): WireTransaction {
-    val componentGroups = createComponentGroups(inputs, outputs, commands, attachments, notary, timeWindow, emptyList(), null)
+    val componentGroups = createComponentGroups(inputs, outputs, commands, attachments, notary, timeWindow, emptyList(), null, legacyAttachments)
     return WireTransaction(componentGroups, privacySalt, digestService)
 }
 
@@ -251,20 +248,5 @@ fun <R> withTestSerializationEnvIfNotSet(block: () -> R): R {
     }
 }
 
-/**
- * Used to check if particular port is already bound i.e. not vacant
- */
-fun isLocalPortBound(port: Int): Boolean {
-    return try {
-        ServerSocket(port).use {
-            // Successful means that the port was vacant
-            false
-        }
-    } catch (e: IOException) {
-        // Failed to open server socket means that it is already bound by someone
-        true
-    }
-}
-
 @JvmField
 val IS_S390X = System.getProperty("os.arch") == "s390x"

verifier/src/main/kotlin/net/corda/verifier/ExternalVerificationContext.kt

@@ -16,7 +16,7 @@ class ExternalVerificationContext(
         private val externalVerifier: ExternalVerifier,
         private val transactionInputsAndReferences: Map<StateRef, SerializedTransactionState>
 ) : VerificationSupport {
-    override val isResolutionLazy: Boolean get() = false
+    override val isInProcess: Boolean get() = false
 
     override fun getParties(keys: Collection<PublicKey>): List<Party?> = externalVerifier.getParties(keys)
 

verifier/src/main/kotlin/net/corda/verifier/ExternalVerifier.kt

@@ -132,6 +132,7 @@ class ExternalVerifier(
         return URLClassLoader(cordappJarUrls, javaClass.classLoader)
     }
 
+    @Suppress("INVISIBLE_MEMBER")
     private fun verifyTransaction(request: VerificationRequest) {
         val verificationContext = ExternalVerificationContext(appClassLoader, attachmentsClassLoaderCache, this, request.stxInputsAndReferences)
         val result: Try<Unit> = try {