fix(Parcel collection): Convert handshake messages to ASN.1 DER (#65)

Because ProtoBuf was a royal pain in the neck.

build.gradle

@@ -2,8 +2,6 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 buildscript {
     ext.kotlinVersion = '1.4.10'
-    ext.protobufVersion = '3.13.0'
-    ext.protobufGradleVersion = '0.8.13'
     ext.kotlinCoroutinesVersion = '1.3.8'
     ext.ktorVersion = '1.4.1'
     ext.okhttpVersion = '4.9.0'
@@ -16,7 +14,6 @@ plugins {
     id('maven-publish')
     id("com.diffplug.gradle.spotless") version "3.27.1"
     id('jacoco')
-    id("com.google.protobuf") version "$protobufGradleVersion"
     id('idea')
 }
 
@@ -33,7 +30,7 @@ dependencies {
 
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlinVersion")
 
-    api('tech.relaycorp:relaynet:1.36.5')
+    api('tech.relaycorp:relaynet:1.37.0')
     implementation('tech.relaycorp:relaynet-testing:1.0.0')
 
     // Handshake nonce signatures
@@ -48,11 +45,6 @@ dependencies {
     testImplementation("com.squareup.okio:okio:2.9.0")
     testImplementation("org.awaitility:awaitility:4.0.3")
 
-    // Protobuf
-    implementation("com.google.protobuf:protobuf-gradle-plugin:$protobufGradleVersion")
-    implementation("com.google.protobuf:protobuf-java:$protobufVersion")
-    implementation("com.google.protobuf:protobuf-java-util:$protobufVersion")
-
     testImplementation("org.jetbrains.kotlin:kotlin-test")
     testImplementation("org.junit.jupiter:junit-jupiter:5.7.0")
     testImplementation("org.junit.jupiter:junit-jupiter-params:5.7.0")
@@ -80,10 +72,6 @@ tasks.withType(KotlinCompile).all {
     }
 }
 
-protobuf {
-    protoc { artifact = "com.google.protobuf:protoc:$protobufVersion" }
-}
-
 tasks.dokka {
     outputFormat = "html"
     outputDirectory = "$buildDir/docs/api"
@@ -147,20 +135,6 @@ spotless {
     }
 }
 
-// Workaround for https://github.com/google/protobuf-gradle-plugin/issues/391
-configurations {
-    "compileProtoPath" {
-        attributes {
-            attribute(Usage.USAGE_ATTRIBUTE, objects.named(Usage, "java-runtime"))
-        }
-    }
-    "testCompileProtoPath" {
-        attributes {
-            attribute(Usage.USAGE_ATTRIBUTE, objects.named(Usage, "java-runtime"))
-        }
-    }
-}
-
 gradleEnterprise {
     buildScan {
         termsOfServiceUrl = "https://gradle.com/terms-of-service"

settings.gradle.kts

@@ -1,14 +1,5 @@
-/*
- * This file was generated by the Gradle 'init' task.
- *
- * The settings file is used to specify which projects to include in your build.
- *
- * Detailed information about configuring a multi-project build in Gradle can be found
- * in the user manual at https://docs.gradle.org/6.1.1/userguide/multi_project_builds.html
- */
-
-rootProject.name = "poweb"
-
 plugins {
     id("com.gradle.enterprise").version("3.3.4")
 }
+
+rootProject.name = "poweb"

src/main/kotlin/tech/relaycorp/poweb/PoWebClient.kt

@@ -25,13 +25,12 @@ import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.FlowCollector
 import kotlinx.coroutines.flow.flow
 import okhttp3.OkHttpClient
-import tech.relaycorp.poweb.handshake.Challenge
-import tech.relaycorp.poweb.handshake.InvalidChallengeException
-import tech.relaycorp.poweb.handshake.Response
 import tech.relaycorp.relaynet.bindings.pdc.NonceSigner
 import tech.relaycorp.relaynet.bindings.pdc.ParcelCollection
 import tech.relaycorp.relaynet.bindings.pdc.StreamingMode
 import tech.relaycorp.relaynet.messages.InvalidMessageException
+import tech.relaycorp.relaynet.messages.control.HandshakeChallenge
+import tech.relaycorp.relaynet.messages.control.HandshakeResponse
 import tech.relaycorp.relaynet.messages.control.ParcelDelivery
 import tech.relaycorp.relaynet.messages.control.PrivateNodeRegistration
 import tech.relaycorp.relaynet.wrappers.x509.Certificate
@@ -313,12 +312,12 @@ public class PoWebClient internal constructor(
 private suspend fun DefaultClientWebSocketSession.handshake(nonceSigners: Array<NonceSigner>) {
     val challengeRaw = incoming.receive()
     val challenge = try {
-        Challenge.deserialize(challengeRaw.readBytes())
-    } catch (exc: InvalidChallengeException) {
+        HandshakeChallenge.deserialize(challengeRaw.readBytes())
+    } catch (exc: InvalidMessageException) {
         close(CloseReason(CloseReason.Codes.VIOLATED_POLICY, ""))
         throw ServerBindingException("Server sent an invalid handshake challenge", exc)
     }
-    val nonceSignatures = nonceSigners.map { it.sign(challenge.nonce) }.toTypedArray()
-    val response = Response(nonceSignatures)
+    val nonceSignatures = nonceSigners.map { it.sign(challenge.nonce) }.toList()
+    val response = HandshakeResponse(nonceSignatures)
     outgoing.send(Frame.Binary(true, response.serialize()))
 }

src/test/kotlin/tech/relaycorp/poweb/ParcelCollectionTest.kt

@@ -12,7 +12,6 @@ import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertThrows
-import tech.relaycorp.poweb.handshake.InvalidChallengeException
 import tech.relaycorp.poweb.websocket.ActionSequence
 import tech.relaycorp.poweb.websocket.ChallengeAction
 import tech.relaycorp.poweb.websocket.CloseConnectionAction
@@ -24,6 +23,7 @@ import tech.relaycorp.relaynet.bindings.pdc.NonceSigner
 import tech.relaycorp.relaynet.bindings.pdc.StreamingMode
 import tech.relaycorp.relaynet.issueEndpointCertificate
 import tech.relaycorp.relaynet.messages.InvalidMessageException
+import tech.relaycorp.relaynet.messages.control.HandshakeResponse
 import tech.relaycorp.relaynet.messages.control.NonceSignature
 import tech.relaycorp.relaynet.wrappers.generateRSAKeyPair
 import java.nio.charset.Charset
@@ -95,7 +95,7 @@ class ParcelCollectionTest : WebSocketTestCase() {
                 }
 
                 assertEquals("Server sent an invalid handshake challenge", exception.message)
-                assertTrue(exception.cause is InvalidChallengeException)
+                assertTrue(exception.cause is InvalidMessageException)
             }
 
             awaitForConnectionClosure()
@@ -130,9 +130,7 @@ class ParcelCollectionTest : WebSocketTestCase() {
             awaitForConnectionClosure()
 
             assertEquals(1, listener!!.receivedMessages.size)
-            val response = tech.relaycorp.poweb.handshake.Response.deserialize(
-                listener!!.receivedMessages.first()
-            )
+            val response = HandshakeResponse.deserialize(listener!!.receivedMessages.first())
             val nonceSignatures = response.nonceSignatures
             val signature1 = NonceSignature.deserialize(nonceSignatures[0])
             assertEquals(nonce.asList(), signature1.nonce.asList())
@@ -401,7 +399,8 @@ class ParcelCollectionTest : WebSocketTestCase() {
         val certificate = issueEndpointCertificate(
             keyPair.public,
             keyPair.private,
-            ZonedDateTime.now().plusDays(1))
+            ZonedDateTime.now().plusDays(1)
+        )
         return NonceSigner(certificate, keyPair.private)
     }
 }