Merge pull request #2 from corda/feature/CORDA-1947/package_ownership

CORDA-1947 added packageOwnership

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

@@ -2,6 +2,7 @@ package net.corda.core.contracts
 
 import net.corda.core.KeepForDJVM
 import net.corda.core.serialization.CordaSerializable
+import java.security.PublicKey
 
 /**
  * Wrap an attachment in this if it is to be used as an executable contract attachment
@@ -12,7 +13,12 @@ import net.corda.core.serialization.CordaSerializable
  */
 @KeepForDJVM
 @CordaSerializable
-class ContractAttachment @JvmOverloads constructor(val attachment: Attachment, val contract: ContractClassName, val additionalContracts: Set<ContractClassName> = emptySet(), val uploader: String? = null) : Attachment by attachment {
+class ContractAttachment @JvmOverloads constructor(
+        val attachment: Attachment,
+        val contract: ContractClassName,
+        val additionalContracts: Set<ContractClassName> = emptySet(),
+        val uploader: String? = null,
+        override val signers: List<PublicKey> = emptyList()) : Attachment by attachment {
 
     val allContracts: Set<ContractClassName> get() = additionalContracts + contract
 

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

@@ -5,6 +5,7 @@ import net.corda.core.KeepForDJVM
 import net.corda.core.crypto.SecureHash
 import net.corda.core.flows.FlowException
 import net.corda.core.identity.Party
+import net.corda.core.node.services.AttachmentId
 import net.corda.core.serialization.CordaSerializable
 import net.corda.core.utilities.NonEmptySet
 import java.security.PublicKey
@@ -163,4 +164,12 @@ abstract class TransactionVerificationException(val txId: SecureHash, message: S
     @DeleteForDJVM
     class InvalidNotaryChange(txId: SecureHash)
         : TransactionVerificationException(txId, "Detected a notary change. Outputs must use the same notary as inputs", null)
+
+    /**
+     * Thrown to indicate that a contract attachment is not signed by the network-wide package owner.
+     */
+    class ContractAttachmentNotSignedByPackageOwnerException(txId: SecureHash, val attachmentHash: AttachmentId, val contractClass: String) : TransactionVerificationException(txId,
+            """The Contract attachment JAR: $attachmentHash containing the contract: $contractClass is not signed by the owner specified in the network parameters.
+           Please check the source of this attachment and if it is malicious contact your zone operator to report this incident.
+           For details see: https://docs.corda.net/network-map.html#network-parameters""".trimIndent(), null)
 }

core/src/main/kotlin/net/corda/core/node/NetworkParameters.kt

@@ -7,6 +7,7 @@ import net.corda.core.node.services.AttachmentId
 import net.corda.core.serialization.CordaSerializable
 import net.corda.core.serialization.DeprecatedConstructorForDeserialization
 import net.corda.core.utilities.days
+import java.security.PublicKey
 import java.time.Duration
 import java.time.Instant
 
@@ -22,6 +23,7 @@ import java.time.Instant
  * of parameters.
  * @property whitelistedContractImplementations List of whitelisted jars containing contract code for each contract class.
  *  This will be used by [net.corda.core.contracts.WhitelistedByZoneAttachmentConstraint]. [You can learn more about contract constraints here](https://docs.corda.net/api-contract-constraints.html).
+ * @property packageOwnership List of the network-wide java packages that were successfully claimed by their owners. Any CorDapp JAR that offers contracts and states in any of these packages must be signed by the owner.
  * @property eventHorizon Time after which nodes will be removed from the network map if they have not been seen
  * during this period
  */
@@ -35,7 +37,8 @@ data class NetworkParameters(
         val modifiedTime: Instant,
         val epoch: Int,
         val whitelistedContractImplementations: Map<String, List<AttachmentId>>,
-        val eventHorizon: Duration
+        val eventHorizon: Duration,
+        val packageOwnership: Map<JavaPackageName, PublicKey>
 ) {
     @DeprecatedConstructorForDeserialization(1)
     constructor (minimumPlatformVersion: Int,
@@ -52,7 +55,28 @@ data class NetworkParameters(
             modifiedTime,
             epoch,
             whitelistedContractImplementations,
-            Int.MAX_VALUE.days
+            Int.MAX_VALUE.days,
+            emptyMap()
+    )
+
+    @DeprecatedConstructorForDeserialization(2)
+    constructor (minimumPlatformVersion: Int,
+                 notaries: List<NotaryInfo>,
+                 maxMessageSize: Int,
+                 maxTransactionSize: Int,
+                 modifiedTime: Instant,
+                 epoch: Int,
+                 whitelistedContractImplementations: Map<String, List<AttachmentId>>,
+                 eventHorizon: Duration
+    ) : this(minimumPlatformVersion,
+            notaries,
+            maxMessageSize,
+            maxTransactionSize,
+            modifiedTime,
+            epoch,
+            whitelistedContractImplementations,
+            eventHorizon,
+            emptyMap()
     )
 
     init {
@@ -63,6 +87,7 @@ data class NetworkParameters(
         require(maxTransactionSize > 0) { "maxTransactionSize must be at least 1" }
         require(maxTransactionSize <= maxMessageSize) { "maxTransactionSize cannot be bigger than maxMessageSize" }
         require(!eventHorizon.isNegative) { "eventHorizon must be positive value" }
+        require(noOverlap(packageOwnership.keys)) { "multiple packages added to the packageOwnership overlap." }
     }
 
     fun copy(minimumPlatformVersion: Int,
@@ -83,6 +108,25 @@ data class NetworkParameters(
                 eventHorizon = eventHorizon)
     }
 
+    fun copy(minimumPlatformVersion: Int,
+             notaries: List<NotaryInfo>,
+             maxMessageSize: Int,
+             maxTransactionSize: Int,
+             modifiedTime: Instant,
+             epoch: Int,
+             whitelistedContractImplementations: Map<String, List<AttachmentId>>,
+             eventHorizon: Duration
+    ): NetworkParameters {
+        return copy(minimumPlatformVersion = minimumPlatformVersion,
+                notaries = notaries,
+                maxMessageSize = maxMessageSize,
+                maxTransactionSize = maxTransactionSize,
+                modifiedTime = modifiedTime,
+                epoch = epoch,
+                whitelistedContractImplementations = whitelistedContractImplementations,
+                eventHorizon = eventHorizon)
+    }
+
     override fun toString(): String {
         return """NetworkParameters {
       minimumPlatformVersion=$minimumPlatformVersion
@@ -94,9 +138,17 @@ data class NetworkParameters(
       }
       eventHorizon=$eventHorizon
       modifiedTime=$modifiedTime
-  epoch=$epoch
+      epoch=$epoch,
+      packageOwnership= {
+        ${packageOwnership.keys.joinToString()}}
+      }
   }"""
     }
+
+    /**
+     * Returns the public key of the package owner of the [contractClassName], or null if not owned.
+     */
+    fun getOwnerOf(contractClassName: String): PublicKey? = this.packageOwnership.filterKeys { it.owns(contractClassName) }.values.singleOrNull()
 }
 
 /**
@@ -113,3 +165,32 @@ data class NotaryInfo(val identity: Party, val validating: Boolean)
  * version.
  */
 class ZoneVersionTooLowException(message: String) : CordaRuntimeException(message)
+
+/**
+ * A wrapper for a legal java package. Used by the network parameters to store package ownership.
+ */
+@CordaSerializable
+data class JavaPackageName(val name: String) {
+    init {
+        require(isPackageValid(name)) { "Attempting to whitelist illegal java package: $name" }
+    }
+
+    /**
+     * Returns true if the [fullClassName] is in a subpackage of the current package.
+     * E.g.: "com.megacorp" owns "com.megacorp.tokens.MegaToken"
+     *
+     * Note: The ownership check is ignoring case to prevent people from just releasing a jar with: "com.megaCorp.megatoken" and pretend they are MegaCorp.
+     * By making the check case insensitive, the node will require that the jar is signed by MegaCorp, so the attack fails.
+     */
+    fun owns(fullClassName: String) = fullClassName.startsWith("${name}.", ignoreCase = true)
+}
+
+// Check if a string is a legal Java package name.
+private fun isPackageValid(packageName: String): Boolean = packageName.isNotEmpty() && !packageName.endsWith(".") && packageName.split(".").all { token ->
+    Character.isJavaIdentifierStart(token[0]) && token.toCharArray().drop(1).all { Character.isJavaIdentifierPart(it) }
+}
+
+// Make sure that packages don't overlap so that ownership is clear.
+private fun noOverlap(packages: Collection<JavaPackageName>) = packages.all { currentPackage ->
+    packages.none { otherPackage -> otherPackage != currentPackage && otherPackage.name.startsWith("${currentPackage.name}.") }
+}

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

@@ -197,7 +197,7 @@ data class ContractUpgradeLedgerTransaction(
     private fun verifyConstraints() {
         val attachmentForConstraintVerification = AttachmentWithContext(
                 legacyContractAttachment as? ContractAttachment
-                        ?: ContractAttachment(legacyContractAttachment, legacyContractClassName),
+                        ?: ContractAttachment(legacyContractAttachment, legacyContractClassName, signers = legacyContractAttachment.signers),
                 upgradedContract.legacyContract,
                 networkParameters.whitelistedContractImplementations
         )

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

@@ -3,6 +3,7 @@ package net.corda.core.transactions
 import net.corda.core.KeepForDJVM
 import net.corda.core.contracts.*
 import net.corda.core.crypto.SecureHash
+import net.corda.core.crypto.isFulfilledBy
 import net.corda.core.identity.Party
 import net.corda.core.internal.AttachmentWithContext
 import net.corda.core.internal.castIfPossible
@@ -81,6 +82,7 @@ data class LedgerTransaction @JvmOverloads constructor(
         val contractAttachmentsByContract: Map<ContractClassName, ContractAttachment> = getUniqueContractAttachmentsByContract()
 
         // TODO - verify for version downgrade
+        validatePackageOwnership(contractAttachmentsByContract)
         validateStatesAgainstContract()
         verifyConstraintsValidity(contractAttachmentsByContract)
         verifyConstraints(contractAttachmentsByContract)
@@ -105,6 +107,30 @@ data class LedgerTransaction @JvmOverloads constructor(
         }
     }
 
+    /**
+     * Verify that for each contract the network wide package owner is respected.
+     *
+     * TODO - revisit once transaction contains network parameters.
+     */
+    private fun validatePackageOwnership(contractAttachmentsByContract: Map<ContractClassName, ContractAttachment>) {
+        // This should never happen once we have network parameters in the transaction.
+        if (networkParameters == null) {
+            return
+        }
+
+        val contractsAndOwners = allStates.mapNotNull { transactionState ->
+            val contractClassName = transactionState.contract
+            networkParameters.getOwnerOf(contractClassName)?.let { contractClassName to it }
+        }.toMap()
+
+        contractsAndOwners.forEach { contract, owner ->
+            val attachment = contractAttachmentsByContract[contract]!!
+            if (!owner.isFulfilledBy(attachment.signers)) {
+                throw TransactionVerificationException.ContractAttachmentNotSignedByPackageOwnerException(this.id, id, contract)
+            }
+        }
+    }
+
     /**
      * Enforces the validity of the actual constraints.
      * * Constraints should be one of the valid supported ones.

core/src/test/kotlin/net/corda/core/JarSignatureTestUtils.kt

@@ -0,0 +1,45 @@
+package net.corda.core
+
+import net.corda.core.internal.JarSignatureCollector
+import net.corda.core.internal.div
+import net.corda.nodeapi.internal.crypto.loadKeyStore
+import java.io.FileInputStream
+import java.nio.file.Path
+import java.nio.file.Paths
+import java.security.PublicKey
+import java.util.jar.JarInputStream
+import kotlin.test.assertEquals
+
+object JarSignatureTestUtils {
+    val bin = Paths.get(System.getProperty("java.home")).let { if (it.endsWith("jre")) it.parent else it } / "bin"
+
+    fun Path.executeProcess(vararg command: String) {
+        val shredder = (this / "_shredder").toFile() // No need to delete after each test.
+        assertEquals(0, ProcessBuilder()
+                .inheritIO()
+                .redirectOutput(shredder)
+                .redirectError(shredder)
+                .directory(this.toFile())
+                .command((bin / command[0]).toString(), *command.sliceArray(1 until command.size))
+                .start()
+                .waitFor())
+    }
+
+    fun Path.generateKey(alias: String, password: String, name: String) =
+            executeProcess("keytool", "-genkey", "-keystore", "_teststore", "-storepass", "storepass", "-keyalg", "RSA", "-alias", alias, "-keypass", password, "-dname", name)
+
+    fun Path.createJar(fileName: String, vararg contents: String) =
+            executeProcess(*(arrayOf("jar", "cvf", fileName) + contents))
+
+    fun Path.updateJar(fileName: String, vararg contents: String) =
+            executeProcess(*(arrayOf("jar", "uvf", fileName) + contents))
+
+    fun Path.signJar(fileName: String, alias: String, password: String): PublicKey {
+        executeProcess("jarsigner", "-keystore", "_teststore", "-storepass", "storepass", "-keypass", password, fileName, alias)
+        val ks = loadKeyStore(this.resolve("_teststore"), "storepass")
+        return ks.getCertificate(alias).publicKey
+    }
+
+    fun Path.getJarSigners(fileName: String) =
+            JarInputStream(FileInputStream((this / fileName).toFile())).use(JarSignatureCollector::collectSigners)
+}

core/src/test/kotlin/net/corda/core/contracts/PackageOwnershipVerificationTests.kt

@@ -0,0 +1,95 @@
+package net.corda.core.contracts
+
+import com.nhaarman.mockito_kotlin.doReturn
+import com.nhaarman.mockito_kotlin.whenever
+import net.corda.core.crypto.Crypto
+import net.corda.core.crypto.SecureHash
+import net.corda.core.identity.AbstractParty
+import net.corda.core.identity.CordaX500Name
+import net.corda.core.node.JavaPackageName
+import net.corda.core.transactions.LedgerTransaction
+import net.corda.finance.POUNDS
+import net.corda.finance.`issued by`
+import net.corda.finance.contracts.asset.Cash
+import net.corda.node.services.api.IdentityServiceInternal
+import net.corda.testing.common.internal.testNetworkParameters
+import net.corda.testing.core.DUMMY_NOTARY_NAME
+import net.corda.testing.core.SerializationEnvironmentRule
+import net.corda.testing.core.TestIdentity
+import net.corda.testing.internal.rigorousMock
+import net.corda.testing.node.MockServices
+import net.corda.testing.node.ledger
+import org.junit.Rule
+import org.junit.Test
+
+class PackageOwnershipVerificationTests {
+
+    private companion object {
+        val DUMMY_NOTARY = TestIdentity(DUMMY_NOTARY_NAME, 20).party
+        val ALICE = TestIdentity(CordaX500Name("ALICE", "London", "GB"))
+        val ALICE_PARTY get() = ALICE.party
+        val ALICE_PUBKEY get() = ALICE.publicKey
+        val BOB = TestIdentity(CordaX500Name("BOB", "London", "GB"))
+        val BOB_PARTY get() = BOB.party
+        val BOB_PUBKEY get() = BOB.publicKey
+        val dummyContract = "net.corda.core.contracts.DummyContract"
+        val OWNER_KEY_PAIR = Crypto.generateKeyPair()
+    }
+
+    @Rule
+    @JvmField
+    val testSerialization = SerializationEnvironmentRule()
+
+    private val ledgerServices = MockServices(
+            cordappPackages = listOf("net.corda.finance.contracts.asset"),
+            initialIdentity = ALICE,
+            identityService = rigorousMock<IdentityServiceInternal>().also {
+                doReturn(ALICE_PARTY).whenever(it).partyFromKey(ALICE_PUBKEY)
+                doReturn(BOB_PARTY).whenever(it).partyFromKey(BOB_PUBKEY)
+            },
+            networkParameters = testNetworkParameters()
+                    .copy(packageOwnership = mapOf(JavaPackageName("net.corda.core.contracts") to OWNER_KEY_PAIR.public))
+    )
+
+    @Test
+    fun `Happy path - Transaction validates when package signed by owner`() {
+        ledgerServices.ledger(DUMMY_NOTARY) {
+            transaction {
+                attachment(dummyContract, SecureHash.allOnesHash, listOf(OWNER_KEY_PAIR.public))
+                output(dummyContract, "c1", DUMMY_NOTARY, null, HashAttachmentConstraint(SecureHash.allOnesHash), DummyContractState())
+                command(ALICE_PUBKEY, DummyIssue())
+                verifies()
+            }
+        }
+    }
+
+    @Test
+    fun `Transaction validation fails when the selected attachment is not signed by the owner`() {
+        ledgerServices.ledger(DUMMY_NOTARY) {
+            transaction {
+                attachment(dummyContract, SecureHash.allOnesHash, listOf(ALICE_PUBKEY))
+                output(dummyContract, "c1", DUMMY_NOTARY, null, HashAttachmentConstraint(SecureHash.allOnesHash), DummyContractState())
+                command(ALICE_PUBKEY, DummyIssue())
+                failsWith("is not signed by the owner specified in the network parameters")
+            }
+        }
+    }
+
+}
+
+@BelongsToContract(DummyContract::class)
+class DummyContractState : ContractState {
+    override val participants: List<AbstractParty>
+        get() = emptyList()
+}
+
+class DummyContract : Contract {
+    interface Commands : CommandData
+    class Create : Commands
+
+    override fun verify(tx: LedgerTransaction) {
+        //do nothing
+    }
+}
+
+class DummyIssue : TypeOnlyCommandData()

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

@@ -1,8 +1,11 @@
 package net.corda.core.internal
 
-import net.corda.core.identity.CordaX500Name
+import net.corda.core.JarSignatureTestUtils.createJar
+import net.corda.core.JarSignatureTestUtils.generateKey
+import net.corda.core.JarSignatureTestUtils.getJarSigners
+import net.corda.core.JarSignatureTestUtils.signJar
+import net.corda.core.JarSignatureTestUtils.updateJar
 import net.corda.core.identity.Party
-import net.corda.nodeapi.internal.crypto.loadKeyStore
 import net.corda.testing.core.ALICE_NAME
 import net.corda.testing.core.BOB_NAME
 import org.assertj.core.api.Assertions.assertThat
@@ -10,30 +13,14 @@ import org.junit.After
 import org.junit.AfterClass
 import org.junit.BeforeClass
 import org.junit.Test
-import java.io.FileInputStream
 import java.nio.file.Files
 import java.nio.file.Path
-import java.nio.file.Paths
-import java.security.PublicKey
-import java.util.jar.JarInputStream
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
 
 class JarSignatureCollectorTest {
     companion object {
         private val dir = Files.createTempDirectory(JarSignatureCollectorTest::class.simpleName)
-        private val bin = Paths.get(System.getProperty("java.home")).let { if (it.endsWith("jre")) it.parent else it } / "bin"
-        private val shredder = (dir / "_shredder").toFile() // No need to delete after each test.
-
-        fun execute(vararg command: String) {
-            assertEquals(0, ProcessBuilder()
-                    .inheritIO()
-                    .redirectOutput(shredder)
-                    .directory(dir.toFile())
-                    .command((bin / command[0]).toString(), *command.sliceArray(1 until command.size))
-                    .start()
-                    .waitFor())
-        }
 
         private const val FILENAME = "attachment.jar"
         private const val ALICE = "alice"
@@ -41,14 +28,11 @@ class JarSignatureCollectorTest {
         private const val BOB = "bob"
         private const val BOB_PASS = "bobpass"
 
-        private fun generateKey(alias: String, password: String, name: CordaX500Name) =
-                execute("keytool", "-genkey", "-keystore", "_teststore", "-storepass", "storepass", "-keyalg", "RSA", "-alias", alias, "-keypass", password, "-dname", name.toString())
-
         @BeforeClass
         @JvmStatic
         fun beforeClass() {
-            generateKey(ALICE, ALICE_PASS, ALICE_NAME)
-            generateKey(BOB, BOB_PASS, BOB_NAME)
+            dir.generateKey(ALICE, ALICE_PASS, ALICE_NAME.toString())
+            dir.generateKey(BOB, BOB_PASS, BOB_NAME.toString())
 
             (dir / "_signable1").writeLines(listOf("signable1"))
             (dir / "_signable2").writeLines(listOf("signable2"))
@@ -75,49 +59,49 @@ class JarSignatureCollectorTest {
     @Test
     fun `empty jar has no signers`() {
         (dir / "META-INF").createDirectory() // At least one arg is required, and jar cvf conveniently ignores this.
-        createJar("META-INF")
-        assertEquals(emptyList(), getJarSigners())
+        dir.createJar(FILENAME, "META-INF")
+        assertEquals(emptyList(), dir.getJarSigners(FILENAME))
 
         signAsAlice()
-        assertEquals(emptyList(), getJarSigners()) // There needs to have been a file for ALICE to sign.
+        assertEquals(emptyList(), dir.getJarSigners(FILENAME)) // There needs to have been a file for ALICE to sign.
     }
 
     @Test
     fun `unsigned jar has no signers`() {
-        createJar("_signable1")
-        assertEquals(emptyList(), getJarSigners())
+        dir.createJar(FILENAME, "_signable1")
+        assertEquals(emptyList(), dir.getJarSigners(FILENAME))
 
-        updateJar("_signable2")
-        assertEquals(emptyList(), getJarSigners())
+        dir.updateJar(FILENAME, "_signable2")
+        assertEquals(emptyList(), dir.getJarSigners(FILENAME))
     }
 
     @Test
     fun `one signer`() {
-        createJar("_signable1", "_signable2")
+        dir.createJar(FILENAME, "_signable1", "_signable2")
         val key = signAsAlice()
-        assertEquals(listOf(key), getJarSigners())
+        assertEquals(listOf(key), dir.getJarSigners(FILENAME))
 
         (dir / "my-dir").createDirectory()
-        updateJar("my-dir")
-        assertEquals(listOf(key), getJarSigners()) // Unsigned directory is irrelevant.
+        dir.updateJar(FILENAME, "my-dir")
+        assertEquals(listOf(key), dir.getJarSigners(FILENAME)) // Unsigned directory is irrelevant.
     }
 
     @Test
     fun `two signers`() {
-        createJar("_signable1", "_signable2")
+        dir.createJar(FILENAME, "_signable1", "_signable2")
         val key1 = signAsAlice()
         val key2 = signAsBob()
 
-        assertEquals(setOf(key1, key2), getJarSigners().toSet())
+        assertEquals(setOf(key1, key2), dir.getJarSigners(FILENAME).toSet())
     }
 
     @Test
     fun `all files must be signed by the same set of signers`() {
-        createJar("_signable1")
+        dir.createJar(FILENAME, "_signable1")
         val key1 = signAsAlice()
-        assertEquals(listOf(key1), getJarSigners())
+        assertEquals(listOf(key1), dir.getJarSigners(FILENAME))
 
-        updateJar("_signable2")
+        dir.updateJar(FILENAME, "_signable2")
         signAsBob()
         assertFailsWith<InvalidJarSignersException>(
                 """
@@ -126,41 +110,23 @@ class JarSignatureCollectorTest {
             See https://docs.corda.net/design/data-model-upgrades/signature-constraints.html for details of the
             constraints applied to attachment signatures.
             """.trimIndent().replace('\n', ' ')
-        ) { getJarSigners() }
+        ) { dir.getJarSigners(FILENAME) }
     }
 
     @Test
     fun `bad signature is caught even if the party would not qualify as a signer`() {
         (dir / "volatile").writeLines(listOf("volatile"))
-        createJar("volatile")
+        dir.createJar(FILENAME, "volatile")
         val key1 = signAsAlice()
-        assertEquals(listOf(key1), getJarSigners())
+        assertEquals(listOf(key1), dir.getJarSigners(FILENAME))
 
         (dir / "volatile").writeLines(listOf("garbage"))
-        updateJar("volatile", "_signable1") // ALICE's signature on volatile is now bad.
+        dir.updateJar(FILENAME, "volatile", "_signable1") // ALICE's signature on volatile is now bad.
         signAsBob()
         // The JDK doesn't care that BOB has correctly signed the whole thing, it won't let us process the entry with ALICE's bad signature:
-        assertFailsWith<SecurityException> { getJarSigners() }
+        assertFailsWith<SecurityException> { dir.getJarSigners(FILENAME) }
     }
 
-    //region Helper functions
-    private fun createJar(vararg contents: String) =
-            execute(*(arrayOf("jar", "cvf", FILENAME) + contents))
-
-    private fun updateJar(vararg contents: String) =
-            execute(*(arrayOf("jar", "uvf", FILENAME) + contents))
-
-    private fun signJar(alias: String, password: String): PublicKey {
-        execute("jarsigner", "-keystore", "_teststore", "-storepass", "storepass", "-keypass", password, FILENAME, alias)
-        val ks = loadKeyStore(dir.resolve("_teststore"), "storepass")
-        return ks.getCertificate(alias).publicKey
-    }
-
-    private fun signAsAlice() = signJar(ALICE, ALICE_PASS)
-    private fun signAsBob() = signJar(BOB, BOB_PASS)
-
-    private fun getJarSigners() =
-            JarInputStream(FileInputStream((dir / FILENAME).toFile())).use(JarSignatureCollector::collectSigners)
-    //endregion
-
+    private fun signAsAlice() = dir.signJar(FILENAME, ALICE, ALICE_PASS)
+    private fun signAsBob() = dir.signJar(FILENAME, BOB, BOB_PASS)
 }

core/src/test/kotlin/net/corda/core/transactions/TransactionBuilderTest.kt

@@ -134,5 +134,5 @@ class TransactionBuilderTest {
         override val id: SecureHash get() = throw UnsupportedOperationException()
 
         override val signers: List<PublicKey> get() = parties.map { it.owningKey }
-    }, DummyContract.PROGRAM_ID)
+    }, DummyContract.PROGRAM_ID, signers = parties.map { it.owningKey })
 }

core/src/test/kotlin/net/corda/core/transactions/TransactionTests.kt

@@ -6,6 +6,7 @@ import net.corda.core.contracts.*
 import net.corda.core.crypto.*
 import net.corda.core.crypto.CompositeKey
 import net.corda.core.identity.Party
+import net.corda.testing.common.internal.testNetworkParameters
 import net.corda.testing.contracts.DummyContract
 import net.corda.testing.core.*
 import net.corda.testing.internal.createWireTransaction
@@ -129,7 +130,8 @@ class TransactionTests {
                 id,
                 null,
                 timeWindow,
-                privacySalt
+                privacySalt,
+                testNetworkParameters()
         )
 
         transaction.verify()

docs/source/network-map.rst

@@ -125,6 +125,13 @@ The current set of network parameters:
 :eventHorizon: Time after which nodes are considered to be unresponsive and removed from network map. Nodes republish their
         ``NodeInfo`` on a regular interval. Network map treats that as a heartbeat from the node.
 
+:packageOwnership: List of the network-wide java packages that were successfully claimed by their owners.
+    Any CorDapp JAR that offers contracts and states in any of these packages must be signed by the owner.
+    This ensures that when a node encounters an owned contract it can uniquely identify it and knows that all other nodes can do the same.
+    Encountering an owned contract in a JAR that is not signed by the rightful owner is most likely a sign of malicious behaviour, and should be reported.
+    The transaction verification logic will throw an exception when this happens.
+    Read more about *Package ownership* here :doc:`design/data-model-upgrades/package-namespace-ownership`.
+
 More parameters will be added in future releases to regulate things like allowed port numbers, whether or not IPv6
 connectivity is required for zone members, required cryptographic algorithms and roll-out schedules (e.g. for moving to post quantum cryptography), parameters related to SGX and so on.
 

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

@@ -164,7 +164,9 @@ abstract class AbstractNode<S>(val configuration: NodeConfiguration,
     val cordappProvider = CordappProviderImpl(cordappLoader, CordappConfigFileProvider(), attachments).tokenize()
     @Suppress("LeakingThis")
     val keyManagementService = makeKeyManagementService(identityService).tokenize()
-    val servicesForResolution = ServicesForResolutionImpl(identityService, attachments, cordappProvider, transactionStorage)
+    val servicesForResolution = ServicesForResolutionImpl(identityService, attachments, cordappProvider, transactionStorage).also {
+        attachments.servicesForResolution = it
+    }
     @Suppress("LeakingThis")
     val vaultService = makeVaultService(keyManagementService, servicesForResolution, database).tokenize()
     val nodeProperties = NodePropertiesPersistentStore(StubbedNodeUniqueIdProvider::value, database)
@@ -1052,7 +1054,7 @@ fun createCordaPersistence(databaseConfig: DatabaseConfig,
     // so we end up providing both descriptor and converter. We should re-examine this in later versions to see if
     // either Hibernate can be convinced to stop warning, use the descriptor by default, or something else.
     JavaTypeDescriptorRegistry.INSTANCE.addDescriptor(AbstractPartyDescriptor(wellKnownPartyFromX500Name, wellKnownPartyFromAnonymous))
-    val attributeConverters = listOf(AbstractPartyToX500NameAsStringConverter(wellKnownPartyFromX500Name, wellKnownPartyFromAnonymous))
+    val attributeConverters = listOf(PublicKeyToTextConverter(), AbstractPartyToX500NameAsStringConverter(wellKnownPartyFromX500Name, wellKnownPartyFromAnonymous))
     val jdbcUrl = hikariProperties.getProperty("dataSource.url", "")
     return CordaPersistence(databaseConfig, schemaService.schemaOptions.keys, jdbcUrl, attributeConverters)
 }

node/src/main/kotlin/net/corda/node/serialization/kryo/DefaultKryoCustomizer.kt

@@ -209,15 +209,17 @@ object DefaultKryoCustomizer {
             output.writeString(obj.contract)
             kryo.writeClassAndObject(output, obj.additionalContracts)
             output.writeString(obj.uploader)
+            kryo.writeClassAndObject(output, obj.signers)
         }
 
+        @Suppress("UNCHECKED_CAST")
         override fun read(kryo: Kryo, input: Input, type: Class<ContractAttachment>): ContractAttachment {
             if (kryo.serializationContext() != null) {
                 val attachmentHash = SecureHash.SHA256(input.readBytes(32))
                 val contract = input.readString()
-                @Suppress("UNCHECKED_CAST")
                 val additionalContracts = kryo.readClassAndObject(input) as Set<ContractClassName>
                 val uploader = input.readString()
+                val signers = kryo.readClassAndObject(input) as List<PublicKey>
                 val context = kryo.serializationContext()!!
                 val attachmentStorage = context.serviceHub.attachments
 
@@ -229,14 +231,14 @@ object DefaultKryoCustomizer {
                     override val id = attachmentHash
                 }
 
-                return ContractAttachment(lazyAttachment, contract, additionalContracts, uploader)
+                return ContractAttachment(lazyAttachment, contract, additionalContracts, uploader, signers)
             } else {
                 val attachment = GeneratedAttachment(input.readBytesWithLength())
                 val contract = input.readString()
-                @Suppress("UNCHECKED_CAST")
                 val additionalContracts = kryo.readClassAndObject(input) as Set<ContractClassName>
                 val uploader = input.readString()
-                return ContractAttachment(attachment, contract, additionalContracts, uploader)
+                val signers = kryo.readClassAndObject(input) as List<PublicKey>
+                return ContractAttachment(attachment, contract, additionalContracts, uploader, signers)
             }
         }
     }

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

@@ -6,13 +6,16 @@ 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 net.corda.core.ClientRelevantError
 import net.corda.core.CordaRuntimeException
 import net.corda.core.contracts.Attachment
 import net.corda.core.contracts.ContractAttachment
 import net.corda.core.contracts.ContractClassName
 import net.corda.core.crypto.SecureHash
+import net.corda.core.crypto.isFulfilledBy
 import net.corda.core.crypto.sha256
 import net.corda.core.internal.*
+import net.corda.core.node.ServicesForResolution
 import net.corda.core.node.services.AttachmentId
 import net.corda.core.node.services.vault.AttachmentQueryCriteria
 import net.corda.core.node.services.vault.AttachmentSort
@@ -31,6 +34,7 @@ import java.io.FilterInputStream
 import java.io.IOException
 import java.io.InputStream
 import java.nio.file.Paths
+import java.security.PublicKey
 import java.time.Instant
 import java.util.*
 import java.util.jar.JarInputStream
@@ -46,6 +50,10 @@ class NodeAttachmentService(
         cacheFactory: NamedCacheFactory,
         private val database: CordaPersistence
 ) : AttachmentStorageInternal, SingletonSerializeAsToken() {
+
+    // This is to break the circular dependency.
+    lateinit var servicesForResolution: ServicesForResolution
+
     companion object {
         private val log = contextLogger()
 
@@ -95,7 +103,13 @@ class NodeAttachmentService(
             @Column(name = "contract_class_name", nullable = false)
             @CollectionTable(name = "${NODE_DATABASE_PREFIX}attachments_contracts", joinColumns = [(JoinColumn(name = "att_id", referencedColumnName = "att_id"))],
                     foreignKey = ForeignKey(name = "FK__ctr_class__attachments"))
-            var contractClassNames: List<ContractClassName>? = null
+            var contractClassNames: List<ContractClassName>? = null,
+
+            @ElementCollection(targetClass = PublicKey::class, fetch = FetchType.EAGER)
+            @Column(name = "signer", nullable = false)
+            @CollectionTable(name = "${NODE_DATABASE_PREFIX}attachments_signers", joinColumns = [(JoinColumn(name = "att_id", referencedColumnName = "att_id"))],
+                    foreignKey = ForeignKey(name = "FK__signers__attachments"))
+            var signers: List<PublicKey>? = null
     )
 
     @VisibleForTesting
@@ -213,11 +227,13 @@ class NodeAttachmentService(
 
     private fun loadAttachmentContent(id: SecureHash): Pair<Attachment, ByteArray>? {
         return database.transaction {
-            val attachment = currentDBSession().get(NodeAttachmentService.DBAttachment::class.java, id.toString()) ?: return@transaction null
+            val attachment = currentDBSession().get(NodeAttachmentService.DBAttachment::class.java, id.toString())
+                    ?: return@transaction null
             val attachmentImpl = AttachmentImpl(id, { attachment.content }, checkAttachmentsOnLoad).let {
                 val contracts = attachment.contractClassNames
                 if (contracts != null && contracts.isNotEmpty()) {
-                    ContractAttachment(it, contracts.first(), contracts.drop(1).toSet(), attachment.uploader)
+                    ContractAttachment(it, contracts.first(), contracts.drop(1).toSet(), attachment.uploader, attachment.signers
+                            ?: emptyList())
                 } else {
                     it
                 }
@@ -291,14 +307,19 @@ class NodeAttachmentService(
                 val id = bytes.sha256()
                 if (!hasAttachment(id)) {
                     checkIsAValidJAR(bytes.inputStream())
+
+                    val jarSigners = getSigners(bytes)
+
                     val session = currentDBSession()
                     val attachment = NodeAttachmentService.DBAttachment(
                             attId = id.toString(),
                             content = bytes,
                             uploader = uploader,
                             filename = filename,
-                            contractClassNames = contractClassNames
+                            contractClassNames = contractClassNames,
+                            signers = jarSigners
                     )
+
                     session.save(attachment)
                     attachmentCount.inc()
                     log.info("Stored new attachment $id")
@@ -310,6 +331,9 @@ class NodeAttachmentService(
         }
     }
 
+    private fun getSigners(attachmentBytes: ByteArray) =
+        JarSignatureCollector.collectSigners(JarInputStream(attachmentBytes.inputStream()))
+
     @Suppress("OverridingDeprecatedMember")
     override fun importOrGetAttachment(jar: InputStream): AttachmentId {
         return try {

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

@@ -0,0 +1,18 @@
+package net.corda.node.services.persistence
+
+import net.corda.core.crypto.Crypto
+import net.corda.core.utilities.hexToByteArray
+import net.corda.core.utilities.toHex
+import java.security.PublicKey
+import javax.persistence.AttributeConverter
+import javax.persistence.Converter
+
+/**
+ * Converts to and from a Public key into a hex encoded string.
+ * Used by JPA to automatically map a [PublicKey] to a text column
+ */
+@Converter(autoApply = true)
+class PublicKeyToTextConverter : AttributeConverter<PublicKey, String> {
+    override fun convertToDatabaseColumn(key: PublicKey?): String? = key?.encoded?.toHex()
+    override fun convertToEntityAttribute(text: String?): PublicKey? = text?.let { Crypto.decodePublicKey(it.hexToByteArray()) }
+}

node/src/main/resources/migration/node-core.changelog-v8.xml

@@ -14,4 +14,17 @@
         <renameTable oldTableName="NODE_ATTACHMENTS_CONTRACT_CLASS_NAME" newTableName="NODE_ATTACHMENTS_CONTRACTS" />
     </changeSet>
 
+    <changeSet author="R3.Corda" id="add_signers">
+        <createTable tableName="node_attachments_signers">
+            <column name="att_id" type="NVARCHAR(255)">
+                <constraints nullable="false"/>
+            </column>
+            <column name="signer" type="NVARCHAR(1024)"/>
+        </createTable>
+
+        <addForeignKeyConstraint baseColumnNames="att_id" baseTableName="node_attachments_signers"
+                                 constraintName="FK__signers__attachments"
+                                 referencedColumnNames="att_id" referencedTableName="node_attachments"/>
+    </changeSet>
+
 </databaseChangeLog>

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

@@ -2,6 +2,8 @@ package net.corda.node.internal
 
 import com.nhaarman.mockito_kotlin.doReturn
 import com.nhaarman.mockito_kotlin.whenever
+import net.corda.core.crypto.generateKeyPair
+import net.corda.core.node.JavaPackageName
 import net.corda.core.utilities.OpaqueBytes
 import net.corda.core.utilities.getOrThrow
 import net.corda.finance.DOLLARS
@@ -10,6 +12,7 @@ import net.corda.node.services.config.NotaryConfig
 import net.corda.core.node.NetworkParameters
 import net.corda.nodeapi.internal.network.NetworkParametersCopier
 import net.corda.core.node.NotaryInfo
+import net.corda.core.utilities.days
 import net.corda.testing.core.ALICE_NAME
 import net.corda.testing.core.BOB_NAME
 import net.corda.testing.core.DUMMY_NOTARY_NAME
@@ -65,7 +68,8 @@ class NetworkParametersTest {
     fun `choosing notary not specified in network parameters will fail`() {
         val fakeNotary = mockNet.createNode(InternalMockNodeParameters(legalName = BOB_NAME, configOverrides = {
             val notary = NotaryConfig(false)
-            doReturn(notary).whenever(it).notary}))
+            doReturn(notary).whenever(it).notary
+        }))
         val fakeNotaryId = fakeNotary.info.singleIdentity()
         val alice = mockNet.createPartyNode(ALICE_NAME)
         assertThat(alice.services.networkMapCache.notaryIdentities).doesNotContain(fakeNotaryId)
@@ -87,6 +91,62 @@ class NetworkParametersTest {
         }.withMessage("maxTransactionSize cannot be bigger than maxMessageSize")
     }
 
+    @Test
+    fun `package ownership checks are correct`() {
+        val key1 = generateKeyPair().public
+        val key2 = generateKeyPair().public
+
+        assertThatExceptionOfType(IllegalArgumentException::class.java).isThrownBy {
+            NetworkParameters(1,
+                    emptyList(),
+                    2001,
+                    2000,
+                    Instant.now(),
+                    1,
+                    emptyMap(),
+                    Int.MAX_VALUE.days,
+                    mapOf(
+                            JavaPackageName("com.!example.stuff") to key2
+                    )
+            )
+        }.withMessageContaining("Attempting to whitelist illegal java package")
+
+        assertThatExceptionOfType(IllegalArgumentException::class.java).isThrownBy {
+            NetworkParameters(1,
+                    emptyList(),
+                    2001,
+                    2000,
+                    Instant.now(),
+                    1,
+                    emptyMap(),
+                    Int.MAX_VALUE.days,
+                    mapOf(
+                            JavaPackageName("com.example") to key1,
+                            JavaPackageName("com.example.stuff") to key2
+                    )
+            )
+        }.withMessage("multiple packages added to the packageOwnership overlap.")
+
+        NetworkParameters(1,
+                emptyList(),
+                2001,
+                2000,
+                Instant.now(),
+                1,
+                emptyMap(),
+                Int.MAX_VALUE.days,
+                mapOf(
+                        JavaPackageName("com.example") to key1,
+                        JavaPackageName("com.examplestuff") to key2
+                )
+        )
+
+        assert(JavaPackageName("com.example").owns("com.example.something.MyClass"))
+        assert(!JavaPackageName("com.example").owns("com.examplesomething.MyClass"))
+        assert(!JavaPackageName("com.exam").owns("com.example.something.MyClass"))
+
+    }
+
     // Helpers
     private fun dropParametersToDir(dir: Path, params: NetworkParameters) {
         NetworkParametersCopier(params).install(dir)

node/src/test/kotlin/net/corda/node/services/persistence/NodeAttachmentServiceTest.kt

@@ -4,10 +4,16 @@ import co.paralleluniverse.fibers.Suspendable
 import com.codahale.metrics.MetricRegistry
 import com.google.common.jimfs.Configuration
 import com.google.common.jimfs.Jimfs
+import com.nhaarman.mockito_kotlin.doReturn
+import com.nhaarman.mockito_kotlin.whenever
+import net.corda.core.JarSignatureTestUtils.createJar
+import net.corda.core.JarSignatureTestUtils.generateKey
+import net.corda.core.JarSignatureTestUtils.signJar
 import net.corda.core.crypto.SecureHash
 import net.corda.core.crypto.sha256
 import net.corda.core.flows.FlowLogic
 import net.corda.core.internal.*
+import net.corda.core.node.ServicesForResolution
 import net.corda.core.node.services.vault.AttachmentQueryCriteria
 import net.corda.core.node.services.vault.AttachmentSort
 import net.corda.core.node.services.vault.Builder
@@ -18,32 +24,39 @@ import net.corda.node.services.transactions.PersistentUniquenessProvider
 import net.corda.node.utilities.TestingNamedCacheFactory
 import net.corda.nodeapi.internal.persistence.CordaPersistence
 import net.corda.nodeapi.internal.persistence.DatabaseConfig
+import net.corda.testing.common.internal.testNetworkParameters
+import net.corda.testing.core.ALICE_NAME
 import net.corda.testing.internal.LogHelper
+import net.corda.testing.internal.rigorousMock
 import net.corda.testing.node.MockServices.Companion.makeTestDataSourceProperties
 import net.corda.testing.node.internal.InternalMockNetwork
 import net.corda.testing.node.internal.startFlow
 import org.assertj.core.api.Assertions.assertThatIllegalArgumentException
-import org.junit.After
-import org.junit.Before
-import org.junit.Ignore
-import org.junit.Test
+import org.junit.*
 import java.io.ByteArrayOutputStream
 import java.io.OutputStream
+import java.net.URI
 import java.nio.charset.StandardCharsets
-import java.nio.file.FileAlreadyExistsException
-import java.nio.file.FileSystem
-import java.nio.file.Path
+import java.nio.file.*
+import java.security.PublicKey
 import java.util.jar.JarEntry
 import java.util.jar.JarOutputStream
+import javax.tools.JavaFileObject
+import javax.tools.SimpleJavaFileObject
+import javax.tools.StandardLocation
+import javax.tools.ToolProvider
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
 import kotlin.test.assertNull
 
+
 class NodeAttachmentServiceTest {
+
     // Use an in memory file system for testing attachment storage.
     private lateinit var fs: FileSystem
     private lateinit var database: CordaPersistence
     private lateinit var storage: NodeAttachmentService
+    private val services = rigorousMock<ServicesForResolution>()
 
     @Before
     fun setUp() {
@@ -52,18 +65,40 @@ class NodeAttachmentServiceTest {
         val dataSourceProperties = makeTestDataSourceProperties()
         database = configureDatabase(dataSourceProperties, DatabaseConfig(), { null }, { null })
         fs = Jimfs.newFileSystem(Configuration.unix())
+
+        doReturn(testNetworkParameters()).whenever(services).networkParameters
+
         storage = NodeAttachmentService(MetricRegistry(), TestingNamedCacheFactory(), database).also {
             database.transaction {
                 it.start()
             }
         }
+        storage.servicesForResolution = services
     }
 
     @After
     fun tearDown() {
+        dir.list { subdir ->
+            subdir.forEach(Path::deleteRecursively)
+        }
         database.close()
     }
 
+    @Test
+    fun `importing a signed jar saves the signers to the storage`() {
+        val jarAndSigner = makeTestSignedContractJar("com.example.MyContract")
+        val signedJar = jarAndSigner.first
+        val attachmentId = storage.importAttachment(signedJar.inputStream(), "test", null)
+        assertEquals(listOf(jarAndSigner.second.hash), storage.openAttachment(attachmentId)!!.signers.map { it.hash })
+    }
+
+    @Test
+    fun `importing a non-signed jar will save no signers`() {
+        val jarName = makeTestContractJar("com.example.MyContract")
+        val attachmentId = storage.importAttachment(dir.resolve(jarName).inputStream(), "test", null)
+        assertEquals(0, storage.openAttachment(attachmentId)!!.signers.size)
+    }
+
     @Test
     fun `insert and retrieve`() {
         val (testJar, expectedHash) = makeTestJar()
@@ -289,7 +324,20 @@ class NodeAttachmentServiceTest {
         return Pair(file, file.readAll().sha256())
     }
 
-    private companion object {
+    companion object {
+        private val dir = Files.createTempDirectory(NodeAttachmentServiceTest::class.simpleName)
+
+        @BeforeClass
+        @JvmStatic
+        fun beforeClass() {
+        }
+
+        @AfterClass
+        @JvmStatic
+        fun afterClass() {
+            dir.deleteRecursively()
+        }
+
         private fun makeTestJar(output: OutputStream, extraEntries: List<Pair<String, String>> = emptyList()) {
             output.use {
                 val jar = JarOutputStream(it)
@@ -305,5 +353,48 @@ class NodeAttachmentServiceTest {
                 jar.closeEntry()
             }
         }
+
+        private fun makeTestSignedContractJar(contractName: String): Pair<Path, PublicKey> {
+            val alias = "testAlias"
+            val pwd = "testPassword"
+            dir.generateKey(alias, pwd, ALICE_NAME.toString())
+            val jarName = makeTestContractJar(contractName)
+            val signer = dir.signJar(jarName, alias, pwd)
+            return dir.resolve(jarName) to signer
+        }
+
+        private fun makeTestContractJar(contractName: String): String {
+            val packages = contractName.split(".")
+            val jarName = "testattachment.jar"
+            val className = packages.last()
+            createTestClass(className, packages.subList(0, packages.size - 1))
+            dir.createJar(jarName, "${contractName.replace(".", "/")}.class")
+            return jarName
+        }
+
+        private fun createTestClass(className: String, packages: List<String>): Path {
+            val newClass = """package ${packages.joinToString(".")};
+                import net.corda.core.contracts.*;
+                import net.corda.core.transactions.*;
+
+                public class $className implements Contract {
+                    @Override
+                    public void verify(LedgerTransaction tx) throws IllegalArgumentException {
                     }
                 }
+            """.trimIndent()
+            val compiler = ToolProvider.getSystemJavaCompiler()
+            val source = object : SimpleJavaFileObject(URI.create("string:///${packages.joinToString("/")}/${className}.java"), JavaFileObject.Kind.SOURCE) {
+                override fun getCharContent(ignoreEncodingErrors: Boolean): CharSequence {
+                    return newClass
+                }
+            }
+            val fileManager = compiler.getStandardFileManager(null, null, null)
+            fileManager.setLocation(StandardLocation.CLASS_OUTPUT, listOf(dir.toFile()))
+
+            val compile = compiler.getTask(System.out.writer(), fileManager, null, null, null, listOf(source)).call()
+            return Paths.get(fileManager.list(StandardLocation.CLASS_OUTPUT, "", setOf(JavaFileObject.Kind.CLASS), true).single().name)
+        }
+    }
+
+}

serialization/src/main/kotlin/net/corda/serialization/internal/amqp/custom/ContractAttachmentSerializer.kt

@@ -9,6 +9,7 @@ import net.corda.core.serialization.MissingAttachmentsException
 import net.corda.serialization.internal.GeneratedAttachment
 import net.corda.serialization.internal.amqp.CustomSerializer
 import net.corda.serialization.internal.amqp.SerializerFactory
+import java.security.PublicKey
 
 /**
  * A serializer for [ContractAttachment] that uses a proxy object to write out the full attachment eagerly.
@@ -23,13 +24,13 @@ class ContractAttachmentSerializer(factory: SerializerFactory) : CustomSerialize
         } catch (e: Exception) {
             throw MissingAttachmentsException(listOf(obj.id))
         }
-        return ContractAttachmentProxy(GeneratedAttachment(bytes), obj.contract, obj.additionalContracts, obj.uploader)
+        return ContractAttachmentProxy(GeneratedAttachment(bytes), obj.contract, obj.additionalContracts, obj.uploader, obj.signers)
     }
 
     override fun fromProxy(proxy: ContractAttachmentProxy): ContractAttachment {
-        return ContractAttachment(proxy.attachment, proxy.contract, proxy.contracts, proxy.uploader)
+        return ContractAttachment(proxy.attachment, proxy.contract, proxy.contracts, proxy.uploader, proxy.signers)
     }
 
     @KeepForDJVM
-    data class ContractAttachmentProxy(val attachment: Attachment, val contract: ContractClassName, val contracts: Set<ContractClassName>, val uploader: String?)
+    data class ContractAttachmentProxy(val attachment: Attachment, val contract: ContractClassName, val contracts: Set<ContractClassName>, val uploader: String?, val signers: List<PublicKey>)
 }

testing/test-utils/src/main/kotlin/net/corda/testing/contracts/DummyState.kt

@@ -1,11 +1,13 @@
 package net.corda.testing.contracts
 
+import net.corda.core.contracts.BelongsToContract
 import net.corda.core.contracts.ContractState
 import net.corda.core.identity.AbstractParty
 
 /**
  * Dummy state for use in testing. Not part of any contract, not even the [DummyContract].
  */
+@BelongsToContract(DummyContract::class)
 data class DummyState @JvmOverloads constructor (
         /** Some information that the state represents for test purposes. **/
         val magicNumber: Int = 0,

testing/test-utils/src/main/kotlin/net/corda/testing/services/MockAttachmentStorage.kt

@@ -7,6 +7,7 @@ import net.corda.core.crypto.SecureHash
 import net.corda.core.crypto.sha256
 import net.corda.core.identity.Party
 import net.corda.core.internal.AbstractAttachment
+import net.corda.core.internal.JarSignatureCollector
 import net.corda.core.internal.UNKNOWN_UPLOADER
 import net.corda.core.internal.readFully
 import net.corda.core.node.services.AttachmentId
@@ -71,7 +72,7 @@ class MockAttachmentStorage : AttachmentStorage, SingletonSerializeAsToken() {
         val sha256 = attachmentId ?: bytes.sha256()
         if (sha256 !in files.keys) {
             val baseAttachment = MockAttachment({ bytes }, sha256, signers)
-            val attachment = if (contractClassNames == null || contractClassNames.isEmpty()) baseAttachment else ContractAttachment(baseAttachment, contractClassNames.first(), contractClassNames.toSet(), uploader)
+            val attachment = if (contractClassNames == null || contractClassNames.isEmpty()) baseAttachment else ContractAttachment(baseAttachment, contractClassNames.first(), contractClassNames.toSet(), uploader, signers)
             _files[sha256] = Pair(attachment, bytes)
         }
         return sha256