CORDA-946 - Correct backward compatibility issue with fingerprinting

Backport from Corda master

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/EvolutionSerializer.kt

@@ -177,11 +177,23 @@ class EvolutionSerializerGetter : EvolutionSerializerGetterBase() {
     override fun getEvolutionSerializer(factory: SerializerFactory,
                                         typeNotation: TypeNotation,
                                         newSerializer: AMQPSerializer<Any>,
-                                        schemas: SerializationSchemas): AMQPSerializer<Any> =
-            factory.getSerializersByDescriptor().computeIfAbsent(typeNotation.descriptor.name!!) {
+                                        schemas: SerializationSchemas): AMQPSerializer<Any> {
+        return factory.getSerializersByDescriptor().computeIfAbsent(typeNotation.descriptor.name!!) {
             when (typeNotation) {
                 is CompositeType -> EvolutionSerializer.make(typeNotation, newSerializer as ObjectSerializer, factory)
-                    is RestrictedType -> EnumEvolutionSerializer.make(typeNotation, newSerializer, factory, schemas)
+                is RestrictedType -> {
+                    // The fingerprint of a generic collection can be changed through bug fixes to the
+                    // fingerprinting function making it appear as if the class has altered whereas it hasn't.
+                    // Given we don't support the evolution of these generic containers, if it appears
+                    // one has been changed, simply return the original serializer and associate it with
+                    // both the new and old fingerprint
+                    if (newSerializer is CollectionSerializer || newSerializer is MapSerializer) {
+                        newSerializer
+                    } else {
+                        EnumEvolutionSerializer.make(typeNotation, newSerializer, factory, schemas)
+                    }
+                }
+            }
         }
     }
 }

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/Schema.kt

@@ -460,6 +460,6 @@ private fun fingerprintForObject(
                         .putUnencodedChars(prop.getter.name)
                         .putUnencodedChars(if (prop.getter.mandatory) NOT_NULLABLE_HASH else NULLABLE_HASH)
             }
-    interfacesForSerialization(type, factory).map { fingerprintForType(it, type, alreadySeen, hasher, factory, debugIndent+4) }
+    interfacesForSerialization(type, factory).map { fingerprintForType(it, type, alreadySeen, hasher, factory, debugIndent+1) }
     return hasher
 }

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/carpenter/AMQPSchemaExtensions.kt

@@ -120,16 +120,17 @@ val typeStrToType: Map<Pair<String, Boolean>, Class<out Any?>> = mapOf(
         Pair("byte", false) to Byte::class.javaObjectType
 )
 
+fun String.stripGenerics() : String = if(this.endsWith('>')) {
+    this.substring(0, this.indexOf('<'))
+} else this
+
 fun AMQPField.getTypeAsClass(classloader: ClassLoader) = typeStrToType[Pair(type, mandatory)] ?: when (type) {
     "string" -> String::class.java
     "binary" -> ByteArray::class.java
-    "*" -> if (requires.isEmpty()) Any::class.java else classloader.loadClass(requires[0])
-    else -> {
-        classloader.loadClass(
-        if (type.endsWith("?>")) {
-            type.substring(0, type.indexOf('<'))
-        } else type)
+    "*" -> if (requires.isEmpty()) Any::class.java else {
+        classloader.loadClass(requires[0].stripGenerics())
     }
+    else -> classloader.loadClass(type.stripGenerics())
 }
 
 fun AMQPField.validateType(classloader: ClassLoader) = when (type) {

node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/EvolvabilityTests.kt

@@ -1,12 +1,21 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
+import net.corda.core.crypto.Crypto.generateKeyPair
+import net.corda.core.crypto.SignedData
+import net.corda.core.crypto.sign
 import net.corda.core.serialization.DeprecatedConstructorForDeserialization
 import net.corda.core.serialization.SerializedBytes
+import net.corda.nodeapi.internal.network.NetworkParameters
+import net.corda.nodeapi.internal.network.NotaryInfo
 import net.corda.testing.common.internal.ProjectStructure.projectRootDir
+import net.corda.testing.core.DUMMY_NOTARY_NAME
+import net.corda.testing.core.TestIdentity
+import org.junit.Ignore
 import org.junit.Test
 import java.io.File
 import java.io.NotSerializableException
 import java.net.URI
+import java.time.Instant
 import kotlin.test.assertEquals
 
 // To regenerate any of the binary test files do the following
@@ -462,4 +471,71 @@ class EvolvabilityTests {
         assertEquals(f, db3.f)
         assertEquals(-1, db3.g)
     }
+
+    //
+    // This test uses a NetworkParameters signed set of bytes generated by R3 Corda and
+    // is here to ensure we can still read them. This test exists because of the break in
+    // being able to deserialize an object serialized prior to some fixes to the fingerprinter.
+    //
+    // The file itself was generated from R3 Corda at commit
+    //      6a6b6f256 Skip cache invalidation during init() - caches are still null.
+    //
+    // To regenerate the file un-ignore the test below this one (regenerate broken network parameters),
+    // to regenerate at a specific version add that test to a checkout at the desired sha then take
+    // the resulting file and add to the repo, changing the filename as appropriate
+    //
+    @Test
+    fun readBrokenNetworkParameters(){
+        val sf = testDefaultFactory()
+        sf.register(net.corda.nodeapi.internal.serialization.amqp.custom.InstantSerializer(sf))
+        sf.register(net.corda.nodeapi.internal.serialization.amqp.custom.PublicKeySerializer)
+
+        //
+        // filename breakdown
+        // networkParams - because this is a serialised set of network parameters
+        // r3corda - generated by R3 Corda instead of Corda
+        // 6a6b6f256 - Commit sha of the build that generated the file we're testing against
+        //
+        val resource = "networkParams.r3corda.6a6b6f256"
+
+        val path = EvolvabilityTests::class.java.getResource(resource)
+        val f = File(path.toURI())
+        val sc2 = f.readBytes()
+        val deserializedC = DeserializationInput(sf).deserialize(SerializedBytes<SignedData<NetworkParameters>>(sc2))
+        val networkParams = DeserializationInput(sf).deserialize(deserializedC.raw)
+
+        assertEquals(1000, networkParams.maxMessageSize)
+        assertEquals(1000, networkParams.maxTransactionSize)
+        assertEquals(3, networkParams.minimumPlatformVersion)
+        assertEquals(1, networkParams.notaries.size)
+        assertEquals(TestIdentity(DUMMY_NOTARY_NAME, 20).party, networkParams.notaries.firstOrNull()?.identity)
+    }
+
+    //
+    // This test created a serialized and signed set of Network Parameters to test whether we
+    // can still deserialize them
+    //
+    @Test
+    @Ignore("This test simply regenerates the test file used for readBrokenNetworkParameters")
+    fun `regenerate broken network parameters`() {
+        // note: 6a6b6f256 is the sha that generates the file
+        val resource = "networkParams.<corda version>.<commit sha>"
+        val DUMMY_NOTARY = TestIdentity(DUMMY_NOTARY_NAME, 20).party
+        val networkParameters = NetworkParameters(
+                3, listOf(NotaryInfo(DUMMY_NOTARY, false)),1000, 1000, Instant.EPOCH, 1 )
+
+        val sf = testDefaultFactory()
+        sf.register(net.corda.nodeapi.internal.serialization.amqp.custom.InstantSerializer(sf))
+        sf.register(net.corda.nodeapi.internal.serialization.amqp.custom.PublicKeySerializer)
+
+        val testOutput = TestSerializationOutput(true, sf)
+        val serialized = testOutput.serialize(networkParameters)
+        val keyPair = generateKeyPair()
+        val sig = keyPair.private.sign(serialized.bytes, keyPair.public)
+        val signed = SignedData(serialized, sig)
+        val signedAndSerialized = testOutput.serialize(signed)
+
+        File(URI("$localPath/$resource")).writeBytes( signedAndSerialized.bytes)
+    }
+
 }