feat(RAMF): Implement payload wrapping (#71)

src/main/kotlin/tech/relaycorp/relaynet/messages/Cargo.kt

@@ -1,8 +1,8 @@
 package tech.relaycorp.relaynet.messages
 
 import tech.relaycorp.relaynet.messages.payloads.CargoMessageSet
+import tech.relaycorp.relaynet.ramf.EncryptedRAMFMessage
 import tech.relaycorp.relaynet.ramf.RAMFException
-import tech.relaycorp.relaynet.ramf.RAMFMessage
 import tech.relaycorp.relaynet.ramf.RAMFMessageCompanion
 import tech.relaycorp.relaynet.ramf.RAMFSerializer
 import tech.relaycorp.relaynet.wrappers.x509.Certificate
@@ -22,7 +22,7 @@ class Cargo(
     creationDate: ZonedDateTime? = null,
     ttl: Int? = null,
     senderCertificateChain: Set<Certificate>? = null
-) : RAMFMessage<CargoMessageSet>(
+) : EncryptedRAMFMessage<CargoMessageSet>(
     SERIALIZER,
     recipientAddress,
     payload,

src/main/kotlin/tech/relaycorp/relaynet/messages/CargoCollectionAuthorization.kt

@@ -1,10 +1,10 @@
 package tech.relaycorp.relaynet.messages
 
-import tech.relaycorp.relaynet.messages.payloads.EmptyPayloadPlaintext
+import tech.relaycorp.relaynet.messages.payloads.EmptyPayload
 import tech.relaycorp.relaynet.ramf.RAMFException
-import tech.relaycorp.relaynet.ramf.RAMFMessage
 import tech.relaycorp.relaynet.ramf.RAMFMessageCompanion
 import tech.relaycorp.relaynet.ramf.RAMFSerializer
+import tech.relaycorp.relaynet.ramf.UnencryptedRAMFMessage
 import tech.relaycorp.relaynet.wrappers.x509.Certificate
 import java.io.InputStream
 import java.time.ZonedDateTime
@@ -22,7 +22,7 @@ class CargoCollectionAuthorization(
     creationDate: ZonedDateTime? = null,
     ttl: Int? = null,
     senderCertificateChain: Set<Certificate>? = null
-) : RAMFMessage<EmptyPayloadPlaintext>(
+) : UnencryptedRAMFMessage<EmptyPayload>(
     SERIALIZER,
     recipientAddress,
     payload,
@@ -32,8 +32,7 @@ class CargoCollectionAuthorization(
     ttl,
     senderCertificateChain
 ) {
-    override fun deserializePayload(payloadPlaintext: ByteArray) =
-        EmptyPayloadPlaintext.deserialize(payloadPlaintext)
+    override fun deserializePayload() = EmptyPayload.deserialize(payload)
 
     companion object : RAMFMessageCompanion<CargoCollectionAuthorization> {
         /**

src/main/kotlin/tech/relaycorp/relaynet/messages/Parcel.kt

@@ -1,8 +1,8 @@
 package tech.relaycorp.relaynet.messages
 
 import tech.relaycorp.relaynet.messages.payloads.ServiceMessage
+import tech.relaycorp.relaynet.ramf.EncryptedRAMFMessage
 import tech.relaycorp.relaynet.ramf.RAMFException
-import tech.relaycorp.relaynet.ramf.RAMFMessage
 import tech.relaycorp.relaynet.ramf.RAMFMessageCompanion
 import tech.relaycorp.relaynet.ramf.RAMFSerializer
 import tech.relaycorp.relaynet.wrappers.x509.Certificate
@@ -22,7 +22,7 @@ class Parcel(
     creationDate: ZonedDateTime? = null,
     ttl: Int? = null,
     senderCertificateChain: Set<Certificate>? = null
-) : RAMFMessage<ServiceMessage>(
+) : EncryptedRAMFMessage<ServiceMessage>(
     SERIALIZER,
     recipientAddress,
     payload,

src/main/kotlin/tech/relaycorp/relaynet/messages/payloads/CargoMessageSet.kt

@@ -10,11 +10,11 @@ import tech.relaycorp.relaynet.wrappers.asn1.ASN1Utils
 /**
  * Cargo message set.
  */
-class CargoMessageSet(val messages: Array<ByteArray>) : PayloadPlaintext {
+class CargoMessageSet(val messages: Array<ByteArray>) : EncryptedPayload() {
     /**
      * Serialize cargo message set.
      */
-    override fun serialize(): ByteArray {
+    override fun serializePlaintext(): ByteArray {
         val messagesVector = ASN1EncodableVector(messages.size)
         messages.forEach { messagesVector.add(DEROctetString(it)) }
         val sequence = DERSequence(messagesVector)

src/main/kotlin/tech/relaycorp/relaynet/messages/payloads/EmptyPayloadPlaintext.kt → src/main/kotlin/tech/relaycorp/relaynet/messages/payloads/EmptyPayload.kt

@@ -5,11 +5,11 @@ import tech.relaycorp.relaynet.ramf.RAMFException
 /**
  * Empty payload plaintext.
  */
-class EmptyPayloadPlaintext : PayloadPlaintext {
+class EmptyPayload : UnencryptedPayload() {
     /**
      * Serialize empty payload plaintext.
      */
-    override fun serialize() = ByteArray(0)
+    override fun serializePlaintext() = ByteArray(0)
 
     companion object {
         /**
@@ -18,11 +18,11 @@ class EmptyPayloadPlaintext : PayloadPlaintext {
          * @throws RAMFException if `serialization` is not empty
          */
         @Throws(RAMFException::class)
-        fun deserialize(serialization: ByteArray): EmptyPayloadPlaintext {
+        fun deserialize(serialization: ByteArray): EmptyPayload {
             if (serialization.isNotEmpty()) {
                 throw RAMFException("Payload is not empty")
             }
-            return EmptyPayloadPlaintext()
+            return EmptyPayload()
         }
     }
 }

src/main/kotlin/tech/relaycorp/relaynet/messages/payloads/EncryptedPayload.kt

@@ -0,0 +1,19 @@
+package tech.relaycorp.relaynet.messages.payloads
+
+import tech.relaycorp.relaynet.SymmetricEncryption
+import tech.relaycorp.relaynet.wrappers.cms.SessionlessEnvelopedData
+import tech.relaycorp.relaynet.wrappers.x509.Certificate
+
+abstract class EncryptedPayload : Payload {
+    fun encrypt(
+        recipientCertificate: Certificate,
+        symmetricEncryptionAlgorithm: SymmetricEncryption = SymmetricEncryption.AES_128
+    ): ByteArray {
+        val envelopedData = SessionlessEnvelopedData.encrypt(
+            this.serializePlaintext(),
+            recipientCertificate,
+            symmetricEncryptionAlgorithm
+        )
+        return envelopedData.serialize()
+    }
+}

src/main/kotlin/tech/relaycorp/relaynet/messages/payloads/PayloadPlaintext.kt → src/main/kotlin/tech/relaycorp/relaynet/messages/payloads/Payload.kt

@@ -3,6 +3,6 @@ package tech.relaycorp.relaynet.messages.payloads
 /**
  * RAMF payload in plaintext form.
  */
-interface PayloadPlaintext {
-    fun serialize(): ByteArray
+interface Payload {
+    fun serializePlaintext(): ByteArray
 }

src/main/kotlin/tech/relaycorp/relaynet/messages/payloads/ServiceMessage.kt

@@ -1,7 +1,7 @@
 package tech.relaycorp.relaynet.messages.payloads
 
-class ServiceMessage : PayloadPlaintext {
-    override fun serialize(): ByteArray {
+class ServiceMessage : EncryptedPayload() {
+    override fun serializePlaintext(): ByteArray {
         TODO("Not yet implemented")
     }
 }

src/main/kotlin/tech/relaycorp/relaynet/messages/payloads/UnencryptedPayload.kt

@@ -0,0 +1,3 @@
+package tech.relaycorp.relaynet.messages.payloads
+
+abstract class UnencryptedPayload : Payload

src/main/kotlin/tech/relaycorp/relaynet/ramf/EncryptedRAMFMessage.kt

@@ -0,0 +1,46 @@
+package tech.relaycorp.relaynet.ramf
+
+import tech.relaycorp.relaynet.messages.payloads.EncryptedPayload
+import tech.relaycorp.relaynet.wrappers.cms.EnvelopedData
+import tech.relaycorp.relaynet.wrappers.cms.EnvelopedDataException
+import tech.relaycorp.relaynet.wrappers.cms.SessionlessEnvelopedData
+import tech.relaycorp.relaynet.wrappers.x509.Certificate
+import java.security.PrivateKey
+import java.time.ZonedDateTime
+
+abstract class EncryptedRAMFMessage<P : EncryptedPayload> internal constructor(
+    serializer: RAMFSerializer,
+    recipientAddress: String,
+    payload: ByteArray,
+    senderCertificate: Certificate,
+    messageId: String?,
+    creationDate: ZonedDateTime?,
+    ttl: Int?,
+    senderCertificateChain: Set<Certificate>?
+) : RAMFMessage<P>(
+    serializer,
+    recipientAddress,
+    payload,
+    senderCertificate,
+    messageId,
+    creationDate,
+    ttl,
+    senderCertificateChain
+) {
+    /**
+     * Decrypt and deserialize payload.
+     *
+     * @throws EnvelopedDataException if the CMS EnvelopedData value is invalid or the
+     *      `privateKey` is invalid.
+     * @throws RAMFException if the plaintext is invalid.
+     */
+    @Throws(RAMFException::class, EnvelopedDataException::class)
+    fun unwrapPayload(privateKey: PrivateKey): P {
+        val envelopedData = EnvelopedData.deserialize(payload) as SessionlessEnvelopedData
+        val plaintext = envelopedData.decrypt(privateKey)
+        return deserializePayload(plaintext)
+    }
+
+    @Throws(RAMFException::class)
+    internal abstract fun deserializePayload(payloadPlaintext: ByteArray): P
+}

src/main/kotlin/tech/relaycorp/relaynet/ramf/RAMFMessage.kt

@@ -2,10 +2,7 @@ package tech.relaycorp.relaynet.ramf
 
 import tech.relaycorp.relaynet.HashingAlgorithm
 import tech.relaycorp.relaynet.dateToZonedDateTime
-import tech.relaycorp.relaynet.messages.payloads.PayloadPlaintext
-import tech.relaycorp.relaynet.wrappers.cms.EnvelopedData
-import tech.relaycorp.relaynet.wrappers.cms.EnvelopedDataException
-import tech.relaycorp.relaynet.wrappers.cms.SessionlessEnvelopedData
+import tech.relaycorp.relaynet.messages.payloads.Payload
 import tech.relaycorp.relaynet.wrappers.x509.Certificate
 import tech.relaycorp.relaynet.wrappers.x509.CertificateException
 import java.net.MalformedURLException
@@ -36,7 +33,7 @@ private val PRIVATE_ADDRESS_REGEX = "^0[a-f0-9]+$".toRegex()
  * @property payload The payload
  * @property senderCertificate The sender's Relaynet PKI certificate
  */
-abstract class RAMFMessage<Payload : PayloadPlaintext> internal constructor(
+abstract class RAMFMessage<P : Payload> internal constructor(
     private val serializer: RAMFSerializer,
     val recipientAddress: String,
     val payload: ByteArray,
@@ -135,23 +132,6 @@ abstract class RAMFMessage<Payload : PayloadPlaintext> internal constructor(
         validateRecipientAddress()
     }
 
-    /**
-     * Decrypt and deserialize payload.
-     *
-     * @throws EnvelopedDataException if the CMS EnvelopedData value is invalid or the
-     *      `privateKey` is invalid.
-     * @throws RAMFException if the plaintext is invalid.
-     */
-    @Throws(RAMFException::class, EnvelopedDataException::class)
-    fun unwrapPayload(privateKey: PrivateKey): Payload {
-        val envelopedData = EnvelopedData.deserialize(payload) as SessionlessEnvelopedData
-        val plaintext = envelopedData.decrypt(privateKey)
-        return deserializePayload(plaintext)
-    }
-
-    @Throws(RAMFException::class)
-    internal abstract fun deserializePayload(payloadPlaintext: ByteArray): Payload
-
     private fun validateTiming() {
         val now = ZonedDateTime.now(UTC)
         if (now < creationDate) {

src/main/kotlin/tech/relaycorp/relaynet/ramf/UnencryptedRAMFMessage.kt

@@ -0,0 +1,28 @@
+package tech.relaycorp.relaynet.ramf
+
+import tech.relaycorp.relaynet.messages.payloads.UnencryptedPayload
+import tech.relaycorp.relaynet.wrappers.x509.Certificate
+import java.time.ZonedDateTime
+
+abstract class UnencryptedRAMFMessage<P : UnencryptedPayload> internal constructor(
+    serializer: RAMFSerializer,
+    recipientAddress: String,
+    payload: ByteArray,
+    senderCertificate: Certificate,
+    messageId: String?,
+    creationDate: ZonedDateTime?,
+    ttl: Int?,
+    senderCertificateChain: Set<Certificate>?
+) : RAMFMessage<P>(
+    serializer,
+    recipientAddress,
+    payload,
+    senderCertificate,
+    messageId,
+    creationDate,
+    ttl,
+    senderCertificateChain
+) {
+    @Throws(RAMFException::class)
+    abstract fun deserializePayload(): P
+}

src/test/kotlin/tech/relaycorp/relaynet/messages/CargoCollectionAuthorizationTest.kt

@@ -1,24 +1,24 @@
 package tech.relaycorp.relaynet.messages
 
 import tech.relaycorp.relaynet.CERTIFICATE
-import tech.relaycorp.relaynet.ramf.RAMFSerializationTestCase
+import tech.relaycorp.relaynet.ramf.RAMFSpecializationTestCase
 import tech.relaycorp.relaynet.wrappers.x509.Certificate
 import kotlin.test.Test
 
 internal class CargoCollectionAuthorizationTest :
-    RAMFSerializationTestCase<CargoCollectionAuthorization>(
+    RAMFSpecializationTestCase<CargoCollectionAuthorization>(
         ::CargoCollectionAuthorization,
         { r: String, p: ByteArray, s: Certificate -> CargoCollectionAuthorization(r, p, s) },
         0x44,
         0x00,
         CargoCollectionAuthorization.Companion
     ) {
     @Test
-    fun `Payload deserialization should be delegated to EmptyPayloadPlaintext`() {
+    fun `Payload deserialization should be delegated to EmptyPayload`() {
         val cca = CargoCollectionAuthorization(
             "https://gb.relaycorp.tech", "".toByteArray(), CERTIFICATE
         )
 
-        cca.deserializePayload("".toByteArray())
+        cca.deserializePayload()
     }
 }

src/test/kotlin/tech/relaycorp/relaynet/messages/CargoTest.kt

@@ -2,12 +2,12 @@ package tech.relaycorp.relaynet.messages
 
 import tech.relaycorp.relaynet.CERTIFICATE
 import tech.relaycorp.relaynet.messages.payloads.CargoMessageSet
-import tech.relaycorp.relaynet.ramf.RAMFSerializationTestCase
+import tech.relaycorp.relaynet.ramf.RAMFSpecializationTestCase
 import tech.relaycorp.relaynet.wrappers.x509.Certificate
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
-internal class CargoTest : RAMFSerializationTestCase<Cargo>(
+internal class CargoTest : RAMFSpecializationTestCase<Cargo>(
     ::Cargo,
     { r: String, p: ByteArray, s: Certificate -> Cargo(r, p, s) },
     0x43,
@@ -19,7 +19,7 @@ internal class CargoTest : RAMFSerializationTestCase<Cargo>(
         val cargoMessageSet = CargoMessageSet(arrayOf("msg1".toByteArray(), "msg2".toByteArray()))
         val cargo = Cargo("https://gb.relaycorp.tech", "".toByteArray(), CERTIFICATE)
 
-        val payloadDeserialized = cargo.deserializePayload(cargoMessageSet.serialize())
+        val payloadDeserialized = cargo.deserializePayload(cargoMessageSet.serializePlaintext())
 
         assertEquals(
             cargoMessageSet.messages.map { it.asList() },

src/test/kotlin/tech/relaycorp/relaynet/messages/ParcelTest.kt

@@ -2,11 +2,11 @@ package tech.relaycorp.relaynet.messages
 
 import org.junit.jupiter.api.assertThrows
 import tech.relaycorp.relaynet.CERTIFICATE
-import tech.relaycorp.relaynet.ramf.RAMFSerializationTestCase
+import tech.relaycorp.relaynet.ramf.RAMFSpecializationTestCase
 import tech.relaycorp.relaynet.wrappers.x509.Certificate
 import kotlin.test.Test
 
-internal class ParcelTest : RAMFSerializationTestCase<Parcel>(
+internal class ParcelTest : RAMFSpecializationTestCase<Parcel>(
     ::Parcel,
     { r: String, p: ByteArray, s: Certificate -> Parcel(r, p, s) },
     0x50,

src/test/kotlin/tech/relaycorp/relaynet/messages/payloads/CargoMessageSetTest.kt

@@ -32,7 +32,7 @@ internal class CargoMessageSetTest {
         fun `An empty array should be serialized as such`() {
             val cargoMessageSet = CargoMessageSet(emptyArray())
 
-            val serialization = cargoMessageSet.serialize()
+            val serialization = cargoMessageSet.serializePlaintext()
 
             val messages = deserializeDERSequence(serialization)
             assertEquals(0, messages.size)
@@ -43,7 +43,7 @@ internal class CargoMessageSetTest {
             val message = "the message".toByteArray()
             val cargoMessageSet = CargoMessageSet(arrayOf(message))
 
-            val serialization = cargoMessageSet.serialize()
+            val serialization = cargoMessageSet.serializePlaintext()
 
             val messages = deserializeDERSequence(serialization)
             assertEquals(1, messages.size)
@@ -57,7 +57,7 @@ internal class CargoMessageSetTest {
             val message2 = "message 1".toByteArray()
             val cargoMessageSet = CargoMessageSet(arrayOf(message1, message2))
 
-            val serialization = cargoMessageSet.serialize()
+            val serialization = cargoMessageSet.serializePlaintext()
 
             val messages = deserializeDERSequence(serialization)
             assertEquals(2, messages.size)