Add NXT cache downloader

I'm still not particularly happy with this: if the JS5 download
finishes before HTTP, it'll time out and kill the whole process.
Similarly, because it takes so long to import the indexes and as we
can't fetch groups in parallel with that, it can often time out early
during the process.

In the long term, I think I am going to try and move most of the logic
outside of the Netty threads and communicate between threads with queues
or channels. This would also allow us to run multiple JS5 clients in
parallel.

The code also needs some tidying up, particularly constants in the
Js5ChannelHandler constructors.

Signed-off-by: Graham <gpe@openrs2.org>

archive/src/main/kotlin/org/openrs2/archive/cache/CacheDownloader.kt

@@ -1,7 +1,9 @@
 package org.openrs2.archive.cache
 
+import org.openrs2.archive.cache.nxt.MusicStreamClient
 import org.openrs2.archive.game.GameDatabase
 import org.openrs2.archive.jav.JavConfig
+import org.openrs2.buffer.ByteBufBodyHandler
 import org.openrs2.net.BootstrapFactory
 import org.openrs2.net.awaitSuspend
 import java.net.URI
@@ -13,6 +15,7 @@ import kotlin.coroutines.suspendCoroutine
 @Singleton
 public class CacheDownloader @Inject constructor(
     private val client: HttpClient,
+    private val byteBufBodyHandler: ByteBufBodyHandler,
     private val bootstrapFactory: BootstrapFactory,
     private val gameDatabase: GameDatabase,
     private val importer: CacheImporter
@@ -21,28 +24,67 @@ public class CacheDownloader @Inject constructor(
         val game = gameDatabase.getGame(gameName) ?: throw Exception("Game not found")
 
         val url = game.url ?: throw Exception("URL not set")
-        val build = game.build ?: throw Exception("Current build not set")
+        val buildMajor = game.buildMajor ?: throw Exception("Current major build not set")
 
         val config = JavConfig.download(client, url)
-        val codebase = config.config[CODEBASE] ?: throw Exception("Codebase missing")
-        val hostname = URI(codebase).host ?: throw Exception("Hostname missing")
 
         val group = bootstrapFactory.createEventLoopGroup()
         try {
             suspendCoroutine<Unit> { continuation ->
                 val bootstrap = bootstrapFactory.createBootstrap(group)
-                val handler = Js5ChannelHandler(
-                    bootstrap,
-                    game.id,
-                    hostname,
-                    PORT,
-                    build,
-                    game.lastMasterIndexId,
-                    continuation,
-                    importer
-                )
-
-                bootstrap.handler(Js5ChannelInitializer(handler))
+
+                val hostname: String
+
+                val initializer = when (gameName) {
+                    "oldschool" -> {
+                        val codebase = config.config[CODEBASE] ?: throw Exception("Codebase missing")
+                        hostname = URI(codebase).host ?: throw Exception("Hostname missing")
+
+                        OsrsJs5ChannelInitializer(
+                            OsrsJs5ChannelHandler(
+                                bootstrap,
+                                game.id,
+                                hostname,
+                                PORT,
+                                buildMajor,
+                                game.lastMasterIndexId,
+                                continuation,
+                                importer,
+                                game.key
+                            )
+                        )
+                    }
+                    "runescape" -> {
+                        val buildMinor = game.buildMinor ?: throw Exception("Current minor build not set")
+
+                        val tokens = config.params.values.filter { TOKEN_REGEX.matches(it) }
+                        val token = tokens.singleOrNull() ?: throw Exception("Multiple candidate tokens: $tokens")
+
+                        hostname = NXT_HOSTNAME
+
+                        val musicStreamClient = MusicStreamClient(client, byteBufBodyHandler, "http://$hostname")
+
+                        NxtJs5ChannelInitializer(
+                            NxtJs5ChannelHandler(
+                                bootstrap,
+                                game.id,
+                                hostname,
+                                PORT,
+                                buildMajor,
+                                buildMinor,
+                                game.lastMasterIndexId,
+                                continuation,
+                                importer,
+                                game.key,
+                                token,
+                                musicStreamClient
+                            )
+                        )
+                    }
+                    else -> throw UnsupportedOperationException()
+                }
+
+                bootstrap.handler(initializer)
                     .connect(hostname, PORT)
             }
         } finally {
@@ -52,6 +94,8 @@ public class CacheDownloader @Inject constructor(
 
     private companion object {
         private const val CODEBASE = "codebase"
+        private const val NXT_HOSTNAME = "content.runescape.com"
         private const val PORT = 443
+        private val TOKEN_REGEX = Regex("[A-Za-z0-9*-]{32}")
     }
 }

archive/src/main/kotlin/org/openrs2/archive/cache/CacheExporter.kt

@@ -11,6 +11,7 @@ import org.openrs2.cache.MasterIndexFormat
 import org.openrs2.cache.Store
 import org.openrs2.crypto.XteaKey
 import org.openrs2.db.Database
+import org.postgresql.util.PGobject
 import java.time.Instant
 import java.util.SortedSet
 import javax.inject.Inject
@@ -52,10 +53,43 @@ public class CacheExporter @Inject constructor(
         }
     }
 
+    public data class Build(val major: Int, val minor: Int?) : Comparable<Build> {
+        override fun compareTo(other: Build): Int {
+            return compareValuesBy(this, other, Build::major, Build::minor)
+        }
+
+        override fun toString(): String {
+            return if (minor != null) {
+                "$major.$minor"
+            } else {
+                major.toString()
+            }
+        }
+
+        internal companion object {
+            internal fun fromPgObject(o: PGobject): Build? {
+                val value = o.value!!
+                require(value.length >= 2)
+
+                val parts = value.substring(1, value.length - 1).split(",")
+                require(parts.size == 2)
+
+                val major = parts[0]
+                val minor = parts[1]
+
+                if (major.isEmpty()) {
+                    return null
+                }
+
+                return Build(major.toInt(), if (minor.isEmpty()) null else minor.toInt())
+            }
+        }
+    }
+
     public data class CacheSummary(
         val id: Int,
         val game: String,
-        val builds: SortedSet<Int>,
+        val builds: SortedSet<Build>,
         val timestamp: Instant?,
         val names: SortedSet<String>,
         val stats: Stats?
@@ -70,7 +104,7 @@ public class CacheExporter @Inject constructor(
 
     public data class Source(
         val game: String,
-        val build: Int?,
+        val build: Build?,
         val timestamp: Instant?,
         val name: String?,
         val description: String?,
@@ -90,26 +124,29 @@ public class CacheExporter @Inject constructor(
         return database.execute { connection ->
             connection.prepareStatement(
                 """
-                SELECT
-                    m.id,
-                    g.name,
-                    array_remove(array_agg(DISTINCT s.build ORDER BY s.build ASC), NULL),
-                    MIN(s.timestamp),
-                    array_remove(array_agg(DISTINCT s.name ORDER BY s.name ASC), NULL),
-                    ms.valid_indexes,
-                    ms.indexes,
-                    ms.valid_groups,
-                    ms.groups,
-                    ms.valid_keys,
-                    ms.keys,
-                    ms.size
-                FROM master_indexes m
-                JOIN sources s ON s.master_index_id = m.id
-                JOIN games g ON g.id = s.game_id
-                LEFT JOIN master_index_stats ms ON ms.master_index_id = m.id
-                GROUP BY m.id, g.name, ms.valid_indexes, ms.indexes, ms.valid_groups, ms.groups, ms.valid_keys, ms.keys,
-                    ms.size
-                ORDER BY g.name ASC, MIN(s.build) ASC, MIN(s.timestamp) ASC
+                SELECT *
+                FROM (
+                    SELECT
+                        m.id,
+                        g.name,
+                        array_remove(array_agg(DISTINCT ROW(s.build_major, s.build_minor)::build ORDER BY ROW(s.build_major, s.build_minor)::build ASC), NULL) builds,
+                        MIN(s.timestamp) AS timestamp,
+                        array_remove(array_agg(DISTINCT s.name ORDER BY s.name ASC), NULL) sources,
+                        ms.valid_indexes,
+                        ms.indexes,
+                        ms.valid_groups,
+                        ms.groups,
+                        ms.valid_keys,
+                        ms.keys,
+                        ms.size
+                    FROM master_indexes m
+                    JOIN sources s ON s.master_index_id = m.id
+                    JOIN games g ON g.id = s.game_id
+                    LEFT JOIN master_index_stats ms ON ms.master_index_id = m.id
+                    GROUP BY m.id, g.name, ms.valid_indexes, ms.indexes, ms.valid_groups, ms.groups, ms.valid_keys, ms.keys,
+                        ms.size
+                ) t
+                ORDER BY t.name ASC, t.builds[1] ASC, t.timestamp ASC
             """.trimIndent()
             ).use { stmt ->
                 stmt.executeQuery().use { rows ->
@@ -118,7 +155,7 @@ public class CacheExporter @Inject constructor(
                     while (rows.next()) {
                         val id = rows.getInt(1)
                         val game = rows.getString(2)
-                        val builds = rows.getArray(3).array as Array<Int>
+                        val builds = rows.getArray(3).array as Array<Any>
                         val timestamp = rows.getTimestamp(4)?.toInstant()
                         val names = rows.getArray(5).array as Array<String>
 
@@ -138,7 +175,7 @@ public class CacheExporter @Inject constructor(
                         caches += CacheSummary(
                             id,
                             game,
-                            builds.toSortedSet(),
+                            builds.mapNotNull { o -> Build.fromPgObject(o as PGobject) }.toSortedSet(),
                             timestamp,
                             names.toSortedSet(),
                             stats
@@ -185,7 +222,7 @@ public class CacheExporter @Inject constructor(
 
                     masterIndex = Unpooled.wrappedBuffer(rows.getBytes(2)).use { compressed ->
                         Js5Compression.uncompress(compressed).use { uncompressed ->
-                            Js5MasterIndex.read(uncompressed, format)
+                            Js5MasterIndex.readUnverified(uncompressed, format)
                         }
                     }
 
@@ -208,7 +245,7 @@ public class CacheExporter @Inject constructor(
 
             connection.prepareStatement(
                 """
-                SELECT g.name, s.build, s.timestamp, s.name, s.description, s.url
+                SELECT g.name, s.build_major, s.build_minor, s.timestamp, s.name, s.description, s.url
                 FROM sources s
                 JOIN games g ON g.id = s.game_id
                 WHERE s.master_index_id = ?
@@ -221,15 +258,26 @@ public class CacheExporter @Inject constructor(
                     while (rows.next()) {
                         val game = rows.getString(1)
 
-                        var build: Int? = rows.getInt(2)
+                        var buildMajor: Int? = rows.getInt(2)
                         if (rows.wasNull()) {
-                            build = null
+                            buildMajor = null
                         }
 
-                        val timestamp = rows.getTimestamp(3)?.toInstant()
-                        val name = rows.getString(4)
-                        val description = rows.getString(5)
-                        val url = rows.getString(6)
+                        var buildMinor: Int? = rows.getInt(3)
+                        if (rows.wasNull()) {
+                            buildMinor = null
+                        }
+
+                        val build = if (buildMajor != null) {
+                            Build(buildMajor, buildMinor)
+                        } else {
+                            null
+                        }
+
+                        val timestamp = rows.getTimestamp(4)?.toInstant()
+                        val name = rows.getString(5)
+                        val description = rows.getString(6)
+                        val url = rows.getString(7)
 
                         sources += Source(game, build, timestamp, name, description, url)
                     }

archive/src/main/kotlin/org/openrs2/archive/cache/CacheImporter.kt

@@ -88,7 +88,8 @@ public class CacheImporter @Inject constructor(
     public suspend fun import(
         store: Store,
         game: String,
-        build: Int?,
+        buildMajor: Int?,
+        buildMinor: Int?,
         timestamp: Instant?,
         name: String?,
         description: String?,
@@ -117,7 +118,8 @@ public class CacheImporter @Inject constructor(
                 SourceType.DISK,
                 masterIndexId,
                 gameId,
-                build,
+                buildMajor,
+                buildMinor,
                 timestamp,
                 name,
                 description,
@@ -182,21 +184,38 @@ public class CacheImporter @Inject constructor(
         buf: ByteBuf,
         format: MasterIndexFormat,
         game: String,
-        build: Int?,
+        buildMajor: Int?,
+        buildMinor: Int?,
         timestamp: Instant?,
         name: String?,
         description: String?,
         url: String?
     ) {
         Js5Compression.uncompress(buf.slice()).use { uncompressed ->
-            val masterIndex = MasterIndex(Js5MasterIndex.read(uncompressed.slice(), format), buf, uncompressed)
+            val masterIndex = MasterIndex(
+                Js5MasterIndex.readUnverified(uncompressed.slice(), format),
+                buf,
+                uncompressed
+            )
 
             database.execute { connection ->
                 prepare(connection)
 
                 val gameId = getGameId(connection, game)
                 val masterIndexId = addMasterIndex(connection, masterIndex)
-                addSource(connection, SourceType.DISK, masterIndexId, gameId, build, timestamp, name, description, url)
+
+                addSource(
+                    connection,
+                    SourceType.DISK,
+                    masterIndexId,
+                    gameId,
+                    buildMajor,
+                    buildMinor,
+                    timestamp,
+                    name,
+                    description,
+                    url
+                )
             }
         }
     }
@@ -206,7 +225,8 @@ public class CacheImporter @Inject constructor(
         buf: ByteBuf,
         uncompressed: ByteBuf,
         gameId: Int,
-        build: Int,
+        buildMajor: Int,
+        buildMinor: Int?,
         lastId: Int?,
         timestamp: Instant
     ): MasterIndexResult {
@@ -216,12 +236,13 @@ public class CacheImporter @Inject constructor(
             connection.prepareStatement(
                 """
                 UPDATE games
-                SET build = ?
+                SET build_major = ?, build_minor = ?
                 WHERE id = ?
             """.trimIndent()
             ).use { stmt ->
-                stmt.setInt(1, build)
-                stmt.setInt(2, gameId)
+                stmt.setInt(1, buildMajor)
+                stmt.setObject(2, buildMinor, Types.INTEGER)
+                stmt.setInt(3, gameId)
 
                 stmt.execute()
             }
@@ -236,7 +257,8 @@ public class CacheImporter @Inject constructor(
                 SourceType.JS5REMOTE,
                 masterIndexId,
                 gameId,
-                build,
+                buildMajor,
+                buildMinor,
                 timestamp,
                 name = "Jagex",
                 description = null,
@@ -451,23 +473,25 @@ public class CacheImporter @Inject constructor(
         type: SourceType,
         masterIndexId: Int,
         gameId: Int,
-        build: Int?,
+        buildMajor: Int?,
+        buildMinor: Int?,
         timestamp: Instant?,
         name: String?,
         description: String?,
         url: String?
     ): Int {
-        if (type == SourceType.JS5REMOTE && build != null) {
+        if (type == SourceType.JS5REMOTE && buildMajor != null) {
             connection.prepareStatement(
                 """
                 SELECT id
                 FROM sources
-                WHERE type = 'js5remote' AND master_index_id = ? AND game_id = ? AND build = ?
+                WHERE type = 'js5remote' AND master_index_id = ? AND game_id = ? AND build_major = ? AND build_minor IS NOT DISTINCT FROM ?
             """.trimIndent()
             ).use { stmt ->
                 stmt.setInt(1, masterIndexId)
                 stmt.setInt(2, gameId)
-                stmt.setInt(3, build)
+                stmt.setInt(3, buildMajor)
+                stmt.setObject(4, buildMinor, Types.INTEGER)
 
                 stmt.executeQuery().use { rows ->
                     if (rows.next()) {
@@ -479,25 +503,26 @@ public class CacheImporter @Inject constructor(
 
         connection.prepareStatement(
             """
-            INSERT INTO sources (type, master_index_id, game_id, build, timestamp, name, description, url)
-            VALUES (?::source_type, ?, ?, ?, ?, ?, ?, ?)
+            INSERT INTO sources (type, master_index_id, game_id, build_major, build_minor, timestamp, name, description, url)
+            VALUES (?::source_type, ?, ?, ?, ?, ?, ?, ?, ?)
             RETURNING id
         """.trimIndent()
         ).use { stmt ->
             stmt.setString(1, type.toString().lowercase())
             stmt.setInt(2, masterIndexId)
             stmt.setInt(3, gameId)
-            stmt.setObject(4, build, Types.INTEGER)
+            stmt.setObject(4, buildMajor, Types.INTEGER)
+            stmt.setObject(5, buildMinor, Types.INTEGER)
 
             if (timestamp != null) {
-                stmt.setObject(5, timestamp.atOffset(ZoneOffset.UTC), Types.TIMESTAMP_WITH_TIMEZONE)
+                stmt.setObject(6, timestamp.atOffset(ZoneOffset.UTC), Types.TIMESTAMP_WITH_TIMEZONE)
             } else {
-                stmt.setNull(5, Types.TIMESTAMP_WITH_TIMEZONE)
+                stmt.setNull(6, Types.TIMESTAMP_WITH_TIMEZONE)
             }
 
-            stmt.setString(6, name)
-            stmt.setString(7, description)
-            stmt.setString(8, url)
+            stmt.setString(7, name)
+            stmt.setString(8, description)
+            stmt.setString(9, url)
 
             stmt.executeQuery().use { rows ->
                 check(rows.next())

archive/src/main/kotlin/org/openrs2/archive/cache/ImportCommand.kt

@@ -13,7 +13,8 @@ import org.openrs2.cli.instant
 import org.openrs2.inject.CloseableInjector
 
 public class ImportCommand : CliktCommand(name = "import") {
-    private val build by option().int()
+    private val buildMajor by option().int()
+    private val buildMinor by option().int()
     private val timestamp by option().instant()
     private val name by option()
     private val description by option()
@@ -31,7 +32,7 @@ public class ImportCommand : CliktCommand(name = "import") {
             val importer = injector.getInstance(CacheImporter::class.java)
 
             Store.open(input).use { store ->
-                importer.import(store, game, build, timestamp, name, description, url)
+                importer.import(store, game, buildMajor, buildMinor, timestamp, name, description, url)
             }
         }
     }

archive/src/main/kotlin/org/openrs2/archive/cache/ImportMasterIndexCommand.kt

@@ -17,7 +17,8 @@ import org.openrs2.inject.CloseableInjector
 import java.nio.file.Files
 
 public class ImportMasterIndexCommand : CliktCommand(name = "import-master-index") {
-    private val build by option().int()
+    private val buildMajor by option().int()
+    private val buildMinor by option().int()
     private val timestamp by option().instant()
     private val name by option()
     private val description by option()
@@ -36,7 +37,7 @@ public class ImportMasterIndexCommand : CliktCommand(name = "import-master-index
             val importer = injector.getInstance(CacheImporter::class.java)
 
             Unpooled.wrappedBuffer(Files.readAllBytes(input)).use { buf ->
-                importer.importMasterIndex(buf, format, game, build, timestamp, name, description, url)
+                importer.importMasterIndex(buf, format, game, buildMajor, buildMinor, timestamp, name, description, url)
             }
         }
     }

archive/src/main/kotlin/org/openrs2/archive/cache/Js5ChannelHandler.kt

@@ -5,8 +5,10 @@ import io.netty.bootstrap.Bootstrap
 import io.netty.buffer.ByteBuf
 import io.netty.channel.ChannelHandler
 import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.ChannelPipeline
 import io.netty.channel.SimpleChannelInboundHandler
 import kotlinx.coroutines.runBlocking
+import org.bouncycastle.crypto.params.RSAKeyParameters
 import org.openrs2.buffer.crc32
 import org.openrs2.buffer.use
 import org.openrs2.cache.Js5Archive
@@ -14,34 +16,36 @@ import org.openrs2.cache.Js5Compression
 import org.openrs2.cache.Js5Index
 import org.openrs2.cache.Js5MasterIndex
 import org.openrs2.cache.MasterIndexFormat
-import org.openrs2.protocol.Rs2Decoder
-import org.openrs2.protocol.Rs2Encoder
-import org.openrs2.protocol.js5.Js5Request
-import org.openrs2.protocol.js5.Js5RequestEncoder
-import org.openrs2.protocol.js5.Js5Response
-import org.openrs2.protocol.js5.Js5ResponseDecoder
-import org.openrs2.protocol.js5.XorDecoder
-import org.openrs2.protocol.login.LoginRequest
-import org.openrs2.protocol.login.LoginResponse
 import java.time.Instant
 import kotlin.coroutines.Continuation
 import kotlin.coroutines.resume
 import kotlin.coroutines.resumeWithException
 
 @ChannelHandler.Sharable
-public class Js5ChannelHandler(
+public abstract class Js5ChannelHandler(
     private val bootstrap: Bootstrap,
     private val gameId: Int,
     private val hostname: String,
     private val port: Int,
-    private var build: Int,
+    protected var buildMajor: Int,
+    protected var buildMinor: Int?,
     private val lastMasterIndexId: Int?,
     private val continuation: Continuation<Unit>,
     private val importer: CacheImporter,
-    private val masterIndexFormat: MasterIndexFormat = MasterIndexFormat.VERSIONED,
-    private val maxInFlightRequests: Int = 200,
-    maxBuildAttempts: Int = 10
+    private val key: RSAKeyParameters?,
+    private val masterIndexFormat: MasterIndexFormat,
+    private val maxInFlightRequests: Int,
+    private val maxBuildAttempts: Int = 10
 ) : SimpleChannelInboundHandler<Any>(Object::class.java) {
+    protected data class InFlightRequest(val prefetch: Boolean, val archive: Int, val group: Int)
+    protected data class PendingRequest(
+        val prefetch: Boolean,
+        val archive: Int,
+        val group: Int,
+        val version: Int,
+        val checksum: Int
+    )
+
     private enum class State {
         ACTIVE,
         CLIENT_OUT_OF_DATE,
@@ -49,39 +53,35 @@ public class Js5ChannelHandler(
     }
 
     private var state = State.ACTIVE
-    private val maxBuild = build + maxBuildAttempts
-    private val inFlightRequests = mutableSetOf<Js5Request.Group>()
-    private val pendingRequests = ArrayDeque<Js5Request.Group>()
+    private var buildAttempts = 0
+    private val inFlightRequests = mutableSetOf<InFlightRequest>()
+    private val pendingRequests = ArrayDeque<PendingRequest>()
     private var masterIndexId: Int = 0
     private var sourceId: Int = 0
     private var masterIndex: Js5MasterIndex? = null
     private lateinit var indexes: Array<Js5Index?>
     private val groups = mutableListOf<CacheImporter.Group>()
 
+    protected abstract fun createInitMessage(): Any
+    protected abstract fun createRequestMessage(prefetch: Boolean, archive: Int, group: Int): Any
+    protected abstract fun createConnectedMessage(): Any?
+    protected abstract fun configurePipeline(pipeline: ChannelPipeline)
+    protected abstract fun incrementVersion()
+
     override fun channelActive(ctx: ChannelHandlerContext) {
-        ctx.writeAndFlush(LoginRequest.InitJs5RemoteConnection(build), ctx.voidPromise())
+        ctx.writeAndFlush(createInitMessage(), ctx.voidPromise())
         ctx.read()
     }
 
-    override fun channelRead0(ctx: ChannelHandlerContext, msg: Any) {
-        when (msg) {
-            is LoginResponse.Js5Ok -> handleOk(ctx)
-            is LoginResponse.ClientOutOfDate -> handleClientOutOfDate(ctx)
-            is LoginResponse -> throw Exception("Invalid response: $msg")
-            is Js5Response -> handleResponse(ctx, msg)
-            else -> throw Exception("Unknown message type: ${msg.javaClass.name}")
-        }
-    }
-
     override fun channelReadComplete(ctx: ChannelHandlerContext) {
         var flush = false
 
         while (inFlightRequests.size < maxInFlightRequests) {
             val request = pendingRequests.removeFirstOrNull() ?: break
-            inFlightRequests += request
+            inFlightRequests += InFlightRequest(request.prefetch, request.archive, request.group)
 
             logger.info { "Requesting archive ${request.archive} group ${request.group}" }
-            ctx.write(request, ctx.voidPromise())
+            ctx.write(createRequestMessage(request.prefetch, request.archive, request.group), ctx.voidPromise())
 
             flush = true
         }
@@ -112,53 +112,60 @@ public class Js5ChannelHandler(
         continuation.resumeWithException(cause)
     }
 
-    private fun handleOk(ctx: ChannelHandlerContext) {
-        val pipeline = ctx.pipeline()
+    protected fun handleOk(ctx: ChannelHandlerContext) {
+        configurePipeline(ctx.pipeline())
 
-        pipeline.remove(Rs2Encoder::class.java)
-        pipeline.remove(Rs2Decoder::class.java)
-        pipeline.addFirst(
-            Js5RequestEncoder,
-            XorDecoder(),
-            Js5ResponseDecoder()
-        )
+        val msg = createConnectedMessage()
+        if (msg != null) {
+            ctx.write(msg, ctx.voidPromise())
+        }
 
-        request(Js5Archive.ARCHIVESET, Js5Archive.ARCHIVESET)
+        request(ctx, Js5Archive.ARCHIVESET, Js5Archive.ARCHIVESET, 0, 0)
     }
 
-    private fun handleClientOutOfDate(ctx: ChannelHandlerContext) {
-        if (++build > maxBuild) {
+    protected fun handleClientOutOfDate(ctx: ChannelHandlerContext) {
+        if (++buildAttempts > maxBuildAttempts) {
             throw Exception("Failed to identify current version")
         }
 
         state = State.CLIENT_OUT_OF_DATE
+        incrementVersion()
+
         ctx.close()
     }
 
-    private fun handleResponse(ctx: ChannelHandlerContext, response: Js5Response) {
-        val request = Js5Request.Group(response.prefetch, response.archive, response.group)
+    protected fun handleResponse(
+        ctx: ChannelHandlerContext,
+        prefetch: Boolean,
+        archive: Int,
+        group: Int,
+        data: ByteBuf
+    ) {
+        val request = InFlightRequest(prefetch, archive, group)
 
         val removed = inFlightRequests.remove(request)
         if (!removed) {
-            val type = if (response.prefetch) {
+            val type = if (prefetch) {
                 "prefetch"
             } else {
                 "urgent"
             }
-            val archive = response.archive
-            val group = response.group
             throw Exception("Received response for $type request (archive $archive group $group) not in-flight")
         }
 
-        if (response.archive == Js5Archive.ARCHIVESET && response.group == Js5Archive.ARCHIVESET) {
-            processMasterIndex(response.data)
-        } else if (response.archive == Js5Archive.ARCHIVESET) {
-            processIndex(response.group, response.data)
+        processResponse(ctx, archive, group, data)
+    }
+
+    protected fun processResponse(ctx: ChannelHandlerContext, archive: Int, group: Int, data: ByteBuf) {
+        if (archive == Js5Archive.ARCHIVESET && group == Js5Archive.ARCHIVESET) {
+            processMasterIndex(ctx, data)
+        } else if (archive == Js5Archive.ARCHIVESET) {
+            processIndex(ctx, group, data)
         } else {
-            processGroup(response.archive, response.group, response.data)
+            processGroup(archive, group, data)
         }
 
-        val complete = pendingRequests.isEmpty() && inFlightRequests.isEmpty()
+        val complete = isComplete()
 
         if (groups.size >= CacheImporter.BATCH_SIZE || complete) {
             runBlocking {
@@ -179,9 +186,13 @@ public class Js5ChannelHandler(
         }
     }
 
-    private fun processMasterIndex(buf: ByteBuf) {
+    protected open fun isComplete(): Boolean {
+        return pendingRequests.isEmpty() && inFlightRequests.isEmpty()
+    }
+
+    private fun processMasterIndex(ctx: ChannelHandlerContext, buf: ByteBuf) {
         Js5Compression.uncompress(buf.slice()).use { uncompressed ->
-            masterIndex = Js5MasterIndex.read(uncompressed.slice(), masterIndexFormat)
+            masterIndex = Js5MasterIndex.read(uncompressed.slice(), masterIndexFormat, key)
 
             val (masterIndexId, sourceId, rawIndexes) = runBlocking {
                 importer.importMasterIndexAndGetIndexes(
@@ -189,7 +200,8 @@ public class Js5ChannelHandler(
                     buf,
                     uncompressed,
                     gameId,
-                    build,
+                    buildMajor,
+                    buildMinor,
                     lastMasterIndexId,
                     timestamp = Instant.now()
                 )
@@ -202,10 +214,15 @@ public class Js5ChannelHandler(
                 indexes = arrayOfNulls(rawIndexes.size)
 
                 for ((archive, index) in rawIndexes.withIndex()) {
+                    val entry = masterIndex!!.entries[archive]
+                    if (entry.version == 0 && entry.checksum == 0) {
+                        continue
+                    }
+
                     if (index != null) {
-                        processIndex(archive, index)
+                        processIndex(ctx, archive, index)
                     } else {
-                        request(Js5Archive.ARCHIVESET, archive)
+                        request(ctx, Js5Archive.ARCHIVESET, archive, entry.version, entry.checksum)
                     }
                 }
             } finally {
@@ -214,7 +231,7 @@ public class Js5ChannelHandler(
         }
     }
 
-    private fun processIndex(archive: Int, buf: ByteBuf) {
+    private fun processIndex(ctx: ChannelHandlerContext, archive: Int, buf: ByteBuf) {
         val checksum = buf.crc32()
         val entry = masterIndex!!.entries[archive]
         if (checksum != entry.checksum) {
@@ -233,7 +250,8 @@ public class Js5ChannelHandler(
                 importer.importIndexAndGetMissingGroups(sourceId, archive, index, buf, uncompressed, lastMasterIndexId)
             }
             for (group in groups) {
-                request(archive, group)
+                val groupEntry = index[group]!!
+                request(ctx, archive, group, groupEntry.version, groupEntry.checksum)
             }
         }
     }
@@ -257,8 +275,8 @@ public class Js5ChannelHandler(
         )
     }
 
-    private fun request(archive: Int, group: Int) {
-        pendingRequests += Js5Request.Group(false, archive, group)
+    protected open fun request(ctx: ChannelHandlerContext, archive: Int, group: Int, version: Int, checksum: Int) {
+        pendingRequests += PendingRequest(false, archive, group, version, checksum)
     }
 
     private fun releaseGroups() {

archive/src/main/kotlin/org/openrs2/archive/cache/NxtJs5ChannelHandler.kt

@@ -0,0 +1,158 @@
+package org.openrs2.archive.cache
+
+import com.github.michaelbull.logging.InlineLogger
+import io.netty.bootstrap.Bootstrap
+import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.ChannelPipeline
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.asCoroutineDispatcher
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.launch
+import org.bouncycastle.crypto.params.RSAKeyParameters
+import org.openrs2.archive.cache.nxt.InitJs5RemoteConnection
+import org.openrs2.archive.cache.nxt.Js5Request
+import org.openrs2.archive.cache.nxt.Js5RequestEncoder
+import org.openrs2.archive.cache.nxt.Js5Response
+import org.openrs2.archive.cache.nxt.Js5ResponseDecoder
+import org.openrs2.archive.cache.nxt.LoginResponse
+import org.openrs2.archive.cache.nxt.MusicStreamClient
+import org.openrs2.buffer.use
+import org.openrs2.cache.MasterIndexFormat
+import org.openrs2.protocol.Rs2Decoder
+import org.openrs2.protocol.Rs2Encoder
+import org.openrs2.protocol.js5.XorDecoder
+import kotlin.coroutines.Continuation
+
+public class NxtJs5ChannelHandler(
+    bootstrap: Bootstrap,
+    gameId: Int,
+    hostname: String,
+    port: Int,
+    buildMajor: Int,
+    buildMinor: Int,
+    lastMasterIndexId: Int?,
+    continuation: Continuation<Unit>,
+    importer: CacheImporter,
+    key: RSAKeyParameters?,
+    private val token: String,
+    private val musicStreamClient: MusicStreamClient,
+    private val maxMinorBuildAttempts: Int = 5
+) : Js5ChannelHandler(
+    bootstrap,
+    gameId,
+    hostname,
+    port,
+    buildMajor,
+    buildMinor,
+    lastMasterIndexId,
+    continuation,
+    importer,
+    key,
+    MasterIndexFormat.LENGTHS,
+    maxInFlightRequests = 500
+) {
+    private data class MusicRequest(val archive: Int, val group: Int, val version: Int, val checksum: Int)
+
+    private var inFlightRequests = 0
+    private val pendingRequests = ArrayDeque<MusicRequest>()
+    private var scope: CoroutineScope? = null
+    private var minorBuildAttempts = 0
+
+    override fun createInitMessage(): Any {
+        return InitJs5RemoteConnection(buildMajor, buildMinor!!, token, 0)
+    }
+
+    override fun createRequestMessage(prefetch: Boolean, archive: Int, group: Int): Any {
+        return Js5Request.Group(prefetch, archive, group, buildMajor)
+    }
+
+    override fun createConnectedMessage(): Any? {
+        return Js5Request.Connected(buildMajor)
+    }
+
+    override fun configurePipeline(pipeline: ChannelPipeline) {
+        pipeline.addBefore("handler", null, Js5RequestEncoder)
+        pipeline.addBefore("handler", null, XorDecoder())
+        pipeline.addBefore("handler", null, Js5ResponseDecoder())
+
+        pipeline.remove(Rs2Encoder::class.java)
+        pipeline.remove(Rs2Decoder::class.java)
+    }
+
+    override fun incrementVersion() {
+        buildMinor = buildMinor!! + 1
+
+        if (++minorBuildAttempts >= maxMinorBuildAttempts) {
+            buildMajor++
+            buildMinor = 1
+        }
+    }
+
+    override fun channelActive(ctx: ChannelHandlerContext) {
+        super.channelActive(ctx)
+        scope = CoroutineScope(ctx.channel().eventLoop().asCoroutineDispatcher())
+    }
+
+    override fun channelInactive(ctx: ChannelHandlerContext) {
+        super.channelInactive(ctx)
+        scope!!.cancel()
+    }
+
+    override fun channelRead0(ctx: ChannelHandlerContext, msg: Any) {
+        when (msg) {
+            is LoginResponse.Js5Ok -> handleOk(ctx)
+            is LoginResponse.ClientOutOfDate -> handleClientOutOfDate(ctx)
+            is LoginResponse -> throw Exception("Invalid response: $msg")
+            is Js5Response -> handleResponse(ctx, msg.prefetch, msg.archive, msg.group, msg.data)
+            else -> throw Exception("Unknown message type: ${msg.javaClass.name}")
+        }
+    }
+
+    override fun channelReadComplete(ctx: ChannelHandlerContext) {
+        super.channelReadComplete(ctx)
+
+        while (inFlightRequests < 6) {
+            val request = pendingRequests.removeFirstOrNull() ?: break
+            inFlightRequests++
+
+            logger.info { "Requesting archive ${request.archive} group ${request.group}" }
+
+            scope!!.launch {
+                val archive = request.archive
+                val group = request.group
+                val version = request.version
+                val checksum = request.checksum
+
+                musicStreamClient.request(archive, group, version, checksum, buildMajor).use { buf ->
+                    inFlightRequests--
+
+                    processResponse(ctx, archive, group, buf)
+
+                    /*
+                     * Inject a fake channelReadComplete event to ensure we
+                     * don't time out and to send any new music requests.
+                     */
+                    ctx.channel().pipeline().fireChannelReadComplete()
+                }
+            }
+        }
+    }
+
+    override fun isComplete(): Boolean {
+        return super.isComplete() && pendingRequests.isEmpty() && inFlightRequests == 0
+    }
+
+    override fun request(ctx: ChannelHandlerContext, archive: Int, group: Int, version: Int, checksum: Int) {
+        if (archive == MUSIC_ARCHIVE) {
+            pendingRequests += MusicRequest(archive, group, version, checksum)
+        } else {
+            super.request(ctx, archive, group, version, checksum)
+        }
+    }
+
+    private companion object {
+        private val logger = InlineLogger()
+
+        private const val MUSIC_ARCHIVE = 40
+    }
+}

archive/src/main/kotlin/org/openrs2/archive/cache/NxtJs5ChannelInitializer.kt

@@ -0,0 +1,22 @@
+package org.openrs2.archive.cache
+
+import io.netty.channel.Channel
+import io.netty.channel.ChannelInitializer
+import io.netty.handler.timeout.ReadTimeoutHandler
+import org.openrs2.archive.cache.nxt.ClientOutOfDateCodec
+import org.openrs2.archive.cache.nxt.InitJs5RemoteConnectionCodec
+import org.openrs2.archive.cache.nxt.Js5OkCodec
+import org.openrs2.protocol.Protocol
+import org.openrs2.protocol.Rs2Decoder
+import org.openrs2.protocol.Rs2Encoder
+
+public class NxtJs5ChannelInitializer(private val handler: NxtJs5ChannelHandler) : ChannelInitializer<Channel>() {
+    override fun initChannel(ch: Channel) {
+        ch.pipeline().addLast(
+            ReadTimeoutHandler(30),
+            Rs2Encoder(Protocol(InitJs5RemoteConnectionCodec)),
+            Rs2Decoder(Protocol(Js5OkCodec, ClientOutOfDateCodec))
+        )
+        ch.pipeline().addLast("handler", handler)
+    }
+}

archive/src/main/kotlin/org/openrs2/archive/cache/OsrsJs5ChannelHandler.kt

@@ -0,0 +1,77 @@
+package org.openrs2.archive.cache
+
+import io.netty.bootstrap.Bootstrap
+import io.netty.channel.ChannelHandlerContext
+import io.netty.channel.ChannelPipeline
+import org.bouncycastle.crypto.params.RSAKeyParameters
+import org.openrs2.cache.MasterIndexFormat
+import org.openrs2.protocol.Rs2Decoder
+import org.openrs2.protocol.Rs2Encoder
+import org.openrs2.protocol.js5.Js5Request
+import org.openrs2.protocol.js5.Js5RequestEncoder
+import org.openrs2.protocol.js5.Js5Response
+import org.openrs2.protocol.js5.Js5ResponseDecoder
+import org.openrs2.protocol.js5.XorDecoder
+import org.openrs2.protocol.login.LoginRequest
+import org.openrs2.protocol.login.LoginResponse
+import kotlin.coroutines.Continuation
+
+public class OsrsJs5ChannelHandler(
+    bootstrap: Bootstrap,
+    gameId: Int,
+    hostname: String,
+    port: Int,
+    build: Int,
+    lastMasterIndexId: Int?,
+    continuation: Continuation<Unit>,
+    importer: CacheImporter,
+    key: RSAKeyParameters?
+) : Js5ChannelHandler(
+    bootstrap,
+    gameId,
+    hostname,
+    port,
+    build,
+    null,
+    lastMasterIndexId,
+    continuation,
+    importer,
+    key,
+    MasterIndexFormat.VERSIONED,
+    maxInFlightRequests = 200
+) {
+    override fun createInitMessage(): Any {
+        return LoginRequest.InitJs5RemoteConnection(buildMajor)
+    }
+
+    override fun createRequestMessage(prefetch: Boolean, archive: Int, group: Int): Any {
+        return Js5Request.Group(prefetch, archive, group)
+    }
+
+    override fun createConnectedMessage(): Any? {
+        return null
+    }
+
+    override fun configurePipeline(pipeline: ChannelPipeline) {
+        pipeline.addBefore("handler", null, Js5RequestEncoder)
+        pipeline.addBefore("handler", null, XorDecoder())
+        pipeline.addBefore("handler", null, Js5ResponseDecoder())
+
+        pipeline.remove(Rs2Encoder::class.java)
+        pipeline.remove(Rs2Decoder::class.java)
+    }
+
+    override fun incrementVersion() {
+        buildMajor++
+    }
+
+    override fun channelRead0(ctx: ChannelHandlerContext, msg: Any) {
+        when (msg) {
+            is LoginResponse.Js5Ok -> handleOk(ctx)
+            is LoginResponse.ClientOutOfDate -> handleClientOutOfDate(ctx)
+            is LoginResponse -> throw Exception("Invalid response: $msg")
+            is Js5Response -> handleResponse(ctx, msg.prefetch, msg.archive, msg.group, msg.data)
+            else -> throw Exception("Unknown message type: ${msg.javaClass.name}")
+        }
+    }
+}

archive/src/main/kotlin/org/openrs2/archive/cache/OsrsJs5ChannelInitializer.kt

@@ -7,13 +7,13 @@ import org.openrs2.protocol.Protocol
 import org.openrs2.protocol.Rs2Decoder
 import org.openrs2.protocol.Rs2Encoder
 
-public class Js5ChannelInitializer(private val handler: Js5ChannelHandler) : ChannelInitializer<Channel>() {
+public class OsrsJs5ChannelInitializer(private val handler: OsrsJs5ChannelHandler) : ChannelInitializer<Channel>() {
     override fun initChannel(ch: Channel) {
         ch.pipeline().addLast(
             ReadTimeoutHandler(30),
             Rs2Encoder(Protocol.LOGIN_UPSTREAM),
-            Rs2Decoder(Protocol.LOGIN_DOWNSTREAM),
-            handler
+            Rs2Decoder(Protocol.LOGIN_DOWNSTREAM)
         )
+        ch.pipeline().addLast("handler", handler)
     }
 }

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/ClientOutOfDateCodec.kt

@@ -0,0 +1,8 @@
+package org.openrs2.archive.cache.nxt
+
+import org.openrs2.protocol.EmptyPacketCodec
+
+public object ClientOutOfDateCodec : EmptyPacketCodec<LoginResponse.ClientOutOfDate>(
+    opcode = 6,
+    packet = LoginResponse.ClientOutOfDate
+)

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/InitJs5RemoteConnection.kt

@@ -0,0 +1,10 @@
+package org.openrs2.archive.cache.nxt
+
+import org.openrs2.protocol.Packet
+
+public data class InitJs5RemoteConnection(
+    public val buildMajor: Int,
+    public val buildMinor: Int,
+    public val token: String,
+    public val language: Int
+) : Packet

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/InitJs5RemoteConnectionCodec.kt

@@ -0,0 +1,29 @@
+package org.openrs2.archive.cache.nxt
+
+import io.netty.buffer.ByteBuf
+import org.openrs2.buffer.readString
+import org.openrs2.buffer.writeString
+import org.openrs2.crypto.StreamCipher
+import org.openrs2.protocol.PacketCodec
+import org.openrs2.protocol.PacketLength
+
+public object InitJs5RemoteConnectionCodec : PacketCodec<InitJs5RemoteConnection>(
+    length = PacketLength.VARIABLE_BYTE,
+    opcode = 15,
+    type = InitJs5RemoteConnection::class.java
+) {
+    override fun decode(input: ByteBuf, cipher: StreamCipher): InitJs5RemoteConnection {
+        val buildMajor = input.readInt()
+        val buildMinor = input.readInt()
+        val token = input.readString()
+        val language = input.readUnsignedByte().toInt()
+        return InitJs5RemoteConnection(buildMajor, buildMinor, token, language)
+    }
+
+    override fun encode(input: InitJs5RemoteConnection, output: ByteBuf, cipher: StreamCipher) {
+        output.writeInt(input.buildMajor)
+        output.writeInt(input.buildMinor)
+        output.writeString(input.token)
+        output.writeByte(input.language)
+    }
+}

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/Js5OkCodec.kt

@@ -0,0 +1,25 @@
+package org.openrs2.archive.cache.nxt
+
+import io.netty.buffer.ByteBuf
+import org.openrs2.crypto.StreamCipher
+import org.openrs2.protocol.PacketCodec
+
+public object Js5OkCodec : PacketCodec<LoginResponse.Js5Ok>(
+    opcode = 0,
+    length = LoginResponse.Js5Ok.LOADING_REQUIREMENTS * 4,
+    type = LoginResponse.Js5Ok::class.java
+) {
+    override fun decode(input: ByteBuf, cipher: StreamCipher): LoginResponse.Js5Ok {
+        val loadingRequirements = mutableListOf<Int>()
+        for (i in 0 until LoginResponse.Js5Ok.LOADING_REQUIREMENTS) {
+            loadingRequirements += input.readInt()
+        }
+        return LoginResponse.Js5Ok(loadingRequirements)
+    }
+
+    override fun encode(input: LoginResponse.Js5Ok, output: ByteBuf, cipher: StreamCipher) {
+        for (requirement in input.loadingRequirements) {
+            output.writeInt(requirement)
+        }
+    }
+}

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/Js5Request.kt

@@ -0,0 +1,14 @@
+package org.openrs2.archive.cache.nxt
+
+public sealed class Js5Request {
+    public data class Group(
+        public val prefetch: Boolean,
+        public val archive: Int,
+        public val group: Int,
+        public val build: Int
+    ) : Js5Request()
+
+    public data class Connected(
+        public val build: Int
+    ) : Js5Request()
+}

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/Js5RequestEncoder.kt

@@ -0,0 +1,36 @@
+package org.openrs2.archive.cache.nxt
+
+import io.netty.buffer.ByteBuf
+import io.netty.channel.ChannelHandler
+import io.netty.channel.ChannelHandlerContext
+import io.netty.handler.codec.MessageToByteEncoder
+
+@ChannelHandler.Sharable
+public object Js5RequestEncoder : MessageToByteEncoder<Js5Request>(Js5Request::class.java) {
+    override fun encode(ctx: ChannelHandlerContext, msg: Js5Request, out: ByteBuf) {
+        when (msg) {
+            is Js5Request.Group -> {
+                out.writeByte(if (msg.prefetch) 32 else 33)
+                out.writeByte(msg.archive)
+                out.writeInt(msg.group)
+                out.writeShort(msg.build)
+                out.writeShort(0)
+            }
+            is Js5Request.Connected -> {
+                out.writeByte(6)
+                out.writeMedium(5)
+                out.writeShort(0)
+                out.writeShort(msg.build)
+                out.writeShort(0)
+            }
+        }
+    }
+
+    override fun allocateBuffer(ctx: ChannelHandlerContext, msg: Js5Request, preferDirect: Boolean): ByteBuf {
+        return if (preferDirect) {
+            ctx.alloc().ioBuffer(10, 10)
+        } else {
+            ctx.alloc().heapBuffer(10, 10)
+        }
+    }
+}

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/Js5Response.kt

@@ -0,0 +1,11 @@
+package org.openrs2.archive.cache.nxt
+
+import io.netty.buffer.ByteBuf
+import io.netty.buffer.DefaultByteBufHolder
+
+public data class Js5Response(
+    public val prefetch: Boolean,
+    public val archive: Int,
+    public val group: Int,
+    public val data: ByteBuf
+) : DefaultByteBufHolder(data)

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/Js5ResponseDecoder.kt

@@ -0,0 +1,121 @@
+package org.openrs2.archive.cache.nxt
+
+import io.netty.buffer.ByteBuf
+import io.netty.channel.ChannelHandlerContext
+import io.netty.handler.codec.ByteToMessageDecoder
+import io.netty.handler.codec.DecoderException
+import kotlin.math.min
+
+public class Js5ResponseDecoder : ByteToMessageDecoder() {
+    private data class Request(val prefetch: Boolean, val archive: Int, val group: Int)
+
+    private enum class State {
+        READ_HEADER,
+        READ_LEN,
+        READ_DATA
+    }
+
+    private var state = State.READ_HEADER
+    private val buffers = mutableMapOf<Request, ByteBuf>()
+    private var request: Request? = null
+
+    override fun decode(ctx: ChannelHandlerContext, input: ByteBuf, out: MutableList<Any>) {
+        if (state == State.READ_HEADER) {
+            if (input.readableBytes() < 5) {
+                return
+            }
+
+            val prefetch: Boolean
+            val archive = input.readUnsignedByte().toInt()
+            var group = input.readInt()
+
+            if (group and 0x80000000.toInt() != 0) {
+                prefetch = true
+                group = group and 0x7FFFFFFF
+            } else {
+                prefetch = false
+            }
+
+            request = Request(prefetch, archive, group)
+
+            if (buffers.containsKey(request)) {
+                state = State.READ_DATA
+            } else {
+                state = State.READ_LEN
+            }
+        }
+
+        if (state == State.READ_LEN) {
+            if (input.readableBytes() < 5) {
+                return
+            }
+
+            val type = input.readUnsignedByte().toInt()
+
+            val len = input.readInt()
+            if (len < 0) {
+                throw DecoderException("Length is negative: $len")
+            }
+
+            val totalLen = if (type == 0) {
+                len + 5
+            } else {
+                len + 9
+            }
+
+            if (totalLen < 0) {
+                throw DecoderException("Total length exceeds maximum ByteBuf size")
+            }
+
+            val data = ctx.alloc().buffer(totalLen, totalLen)
+            data.writeByte(type)
+            data.writeInt(len)
+
+            buffers[request!!] = data
+
+            state = State.READ_DATA
+        }
+
+        if (state == State.READ_DATA) {
+            val data = buffers[request!!]!!
+
+            var blockLen = if (data.writerIndex() == 5) {
+                102400 - 10
+            } else {
+                102400 - 5
+            }
+
+            blockLen = min(blockLen, data.writableBytes())
+
+            if (input.readableBytes() < blockLen) {
+                return
+            }
+
+            data.writeBytes(input, blockLen)
+
+            if (!data.isWritable) {
+                out += Js5Response(request!!.prefetch, request!!.archive, request!!.group, data)
+                buffers.remove(request!!)
+                request = null
+            }
+
+            state = State.READ_HEADER
+        }
+    }
+
+    override fun channelInactive(ctx: ChannelHandlerContext) {
+        super.channelInactive(ctx)
+        reset()
+    }
+
+    override fun handlerRemoved0(ctx: ChannelHandlerContext?) {
+        reset()
+    }
+
+    private fun reset() {
+        buffers.values.forEach(ByteBuf::release)
+        buffers.clear()
+
+        state = State.READ_HEADER
+    }
+}

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/LoginResponse.kt

@@ -0,0 +1,13 @@
+package org.openrs2.archive.cache.nxt
+
+import org.openrs2.protocol.Packet
+
+public sealed class LoginResponse : Packet {
+    public data class Js5Ok(val loadingRequirements: List<Int>) : LoginResponse() {
+        public companion object {
+            public const val LOADING_REQUIREMENTS: Int = 31
+        }
+    }
+
+    public object ClientOutOfDate : LoginResponse()
+}

archive/src/main/kotlin/org/openrs2/archive/cache/nxt/MusicStreamClient.kt

@@ -0,0 +1,30 @@
+package org.openrs2.archive.cache.nxt
+
+import io.netty.buffer.ByteBuf
+import kotlinx.coroutines.future.await
+import org.openrs2.buffer.ByteBufBodyHandler
+import org.openrs2.buffer.use
+import org.openrs2.http.checkStatusCode
+import java.net.URI
+import java.net.http.HttpClient
+import java.net.http.HttpRequest
+
+public class MusicStreamClient(
+    private val client: HttpClient,
+    private val byteBufBodyHandler: ByteBufBodyHandler,
+    private val origin: String
+) {
+    public suspend fun request(archive: Int, group: Int, version: Int, checksum: Int, build: Int): ByteBuf {
+        val uri = URI("$origin/ms?m=0&a=$archive&k=$build&g=$group&c=$checksum&v=$version")
+
+        val request = HttpRequest.newBuilder(uri)
+            .GET()
+            .build()
+
+        val response = client.sendAsync(request, byteBufBodyHandler).await()
+        response.body().use { buf ->
+            response.checkStatusCode()
+            return buf.retain()
+        }
+    }
+}

archive/src/main/kotlin/org/openrs2/archive/game/Game.kt

@@ -1,8 +1,12 @@
 package org.openrs2.archive.game
 
+import org.bouncycastle.crypto.params.RSAKeyParameters
+
 public data class Game(
     public val id: Int,
     public val url: String?,
-    public val build: Int?,
-    public val lastMasterIndexId: Int?
+    public val buildMajor: Int?,
+    public val buildMinor: Int?,
+    public val lastMasterIndexId: Int?,
+    public val key: RSAKeyParameters?
 )

archive/src/main/kotlin/org/openrs2/archive/game/GameDatabase.kt

@@ -1,6 +1,8 @@
 package org.openrs2.archive.game
 
+import org.openrs2.crypto.Rsa
 import org.openrs2.db.Database
+import java.io.StringReader
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -12,7 +14,7 @@ public class GameDatabase @Inject constructor(
         return database.execute { connection ->
             connection.prepareStatement(
                 """
-                SELECT id, url, build, last_master_index_id
+                SELECT id, url, build_major, build_minor, last_master_index_id, key
                 FROM games
                 WHERE name = ?
             """.trimIndent()
@@ -27,17 +29,31 @@ public class GameDatabase @Inject constructor(
                     val id = rows.getInt(1)
                     val url: String? = rows.getString(2)
 
-                    var build: Int? = rows.getInt(3)
+                    var buildMajor: Int? = rows.getInt(3)
                     if (rows.wasNull()) {
-                        build = null
+                        buildMajor = null
                     }
 
-                    var lastMasterIndexId: Int? = rows.getInt(4)
+                    var buildMinor: Int? = rows.getInt(4)
+                    if (rows.wasNull()) {
+                        buildMinor = null
+                    }
+
+                    var lastMasterIndexId: Int? = rows.getInt(5)
                     if (rows.wasNull()) {
                         lastMasterIndexId = null
                     }
 
-                    return@execute Game(id, url, build, lastMasterIndexId)
+                    val pem = rows.getString(6)
+                    val key = if (rows.wasNull()) {
+                        null
+                    } else {
+                        StringReader(pem).use { reader ->
+                            Rsa.readPublicKey(reader)
+                        }
+                    }
+
+                    return@execute Game(id, url, buildMajor, buildMinor, lastMasterIndexId, key)
                 }
             }
         }

archive/src/main/resources/org/openrs2/archive/migrations/V3__nxt.sql

@@ -0,0 +1,49 @@
+-- @formatter:off
+CREATE TYPE build AS (
+    major INTEGER,
+    minor INTEGER
+);
+
+ALTER TABLE games
+    ADD COLUMN key TEXT NULL,
+    ADD COLUMN build_minor INTEGER NULL;
+
+ALTER TABLE games
+    RENAME COLUMN build TO build_major;
+
+ALTER TABLE sources
+    ADD COLUMN build_minor INTEGER NULL;
+
+ALTER TABLE sources
+    RENAME COLUMN build TO build_major;
+
+DROP INDEX sources_master_index_id_game_id_build_idx;
+
+CREATE UNIQUE INDEX ON sources (master_index_id, game_id, build_major)
+    WHERE type = 'js5remote' AND build_minor IS NULL;
+
+CREATE UNIQUE INDEX ON sources (master_index_id, game_id, build_major, build_minor)
+    WHERE type = 'js5remote' AND build_minor IS NOT NULL;
+
+UPDATE games
+SET
+    url = 'https://www.runescape.com/k=5/l=0/jav_config.ws?binaryType=2',
+    build_major = 919,
+    build_minor = 1,
+    key = $$-----BEGIN PUBLIC KEY-----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+-----END PUBLIC KEY-----
+$$
+WHERE name = 'runescape';
+-- @formatter:on

cache/src/main/kotlin/org/openrs2/cache/Js5MasterIndex.kt

@@ -180,6 +180,19 @@ public data class Js5MasterIndex(
         }
 
         public fun read(buf: ByteBuf, format: MasterIndexFormat, key: RSAKeyParameters? = null): Js5MasterIndex {
+            return read(buf, format, key, true)
+        }
+
+        public fun readUnverified(buf: ByteBuf, format: MasterIndexFormat): Js5MasterIndex {
+            return read(buf, format, null, false)
+        }
+
+        private fun read(
+            buf: ByteBuf,
+            format: MasterIndexFormat,
+            key: RSAKeyParameters?,
+            verify: Boolean
+        ): Js5MasterIndex {
             val index = Js5MasterIndex(format)
 
             val start = buf.readerIndex()
@@ -233,24 +246,26 @@ public data class Js5MasterIndex(
                 index.entries += Entry(version, checksum, groups, totalUncompressedLength, digest)
             }
 
-            val end = buf.readerIndex()
+            if (verify) {
+                val end = buf.readerIndex()
 
-            if (format >= MasterIndexFormat.DIGESTS) {
-                val ciphertext = buf.readSlice(buf.readableBytes())
-                decrypt(ciphertext, key).use { plaintext ->
-                    require(plaintext.readableBytes() == SIGNATURE_LENGTH) {
-                        "Invalid signature length"
-                    }
+                if (format >= MasterIndexFormat.DIGESTS) {
+                    val ciphertext = buf.readSlice(buf.readableBytes())
+                    decrypt(ciphertext, key).use { plaintext ->
+                        require(plaintext.readableBytes() == SIGNATURE_LENGTH) {
+                            "Invalid signature length"
+                        }
 
-                    // the client doesn't verify what I presume is the RSA magic byte
-                    plaintext.skipBytes(1)
+                        // the client doesn't verify what I presume is the RSA magic byte
+                        plaintext.skipBytes(1)
 
-                    val expected = ByteArray(Whirlpool.DIGESTBYTES)
-                    plaintext.readBytes(expected)
+                        val expected = ByteArray(Whirlpool.DIGESTBYTES)
+                        plaintext.readBytes(expected)
 
-                    val actual = buf.whirlpool(start, end - start)
-                    require(expected.contentEquals(actual)) {
-                        "Invalid signature"
+                        val actual = buf.whirlpool(start, end - start)
+                        require(expected.contentEquals(actual)) {
+                            "Invalid signature"
+                        }
                     }
                 }
             }

cache/src/test/kotlin/org/openrs2/cache/Js5MasterIndexTest.kt

@@ -206,8 +206,11 @@ class Js5MasterIndexTest {
     @Test
     fun testReadWhirlpool() {
         Unpooled.wrappedBuffer(encodedWhirlpool).use { buf ->
-            val index = Js5MasterIndex.read(buf, MasterIndexFormat.DIGESTS)
+            val index = Js5MasterIndex.read(buf.slice(), MasterIndexFormat.DIGESTS)
             assertEquals(decodedWhirlpool, index)
+
+            val indexUnverified = Js5MasterIndex.readUnverified(buf, MasterIndexFormat.DIGESTS)
+            assertEquals(decodedWhirlpool, indexUnverified)
         }
     }
 
@@ -218,8 +221,11 @@ class Js5MasterIndexTest {
             buf.setByte(lastIndex, buf.getByte(lastIndex).toInt().inv())
 
             assertFailsWith<IllegalArgumentException> {
-                Js5MasterIndex.read(buf, MasterIndexFormat.DIGESTS)
+                Js5MasterIndex.read(buf.slice(), MasterIndexFormat.DIGESTS)
             }
+
+            val index = Js5MasterIndex.readUnverified(buf, MasterIndexFormat.DIGESTS)
+            assertEquals(decodedWhirlpool, index)
         }
     }
 
@@ -227,8 +233,11 @@ class Js5MasterIndexTest {
     fun testReadWhirlpoolInvalidSignatureLength() {
         Unpooled.wrappedBuffer(encodedWhirlpool, 0, encodedWhirlpool.size - 1).use { buf ->
             assertFailsWith<IllegalArgumentException> {
-                Js5MasterIndex.read(buf, MasterIndexFormat.DIGESTS)
+                Js5MasterIndex.read(buf.slice(), MasterIndexFormat.DIGESTS)
             }
+
+            val index = Js5MasterIndex.readUnverified(buf, MasterIndexFormat.DIGESTS)
+            assertEquals(decodedWhirlpool, index)
         }
     }
 
@@ -257,8 +266,11 @@ class Js5MasterIndexTest {
     @Test
     fun testReadSigned() {
         Unpooled.wrappedBuffer(encodedSigned).use { buf ->
-            val index = Js5MasterIndex.read(buf, MasterIndexFormat.DIGESTS, PUBLIC_KEY)
+            val index = Js5MasterIndex.read(buf.slice(), MasterIndexFormat.DIGESTS, PUBLIC_KEY)
             assertEquals(decodedWhirlpool, index)
+
+            val indexUnverified = Js5MasterIndex.readUnverified(buf, MasterIndexFormat.DIGESTS)
+            assertEquals(decodedWhirlpool, indexUnverified)
         }
     }
 
@@ -269,8 +281,11 @@ class Js5MasterIndexTest {
             buf.setByte(lastIndex, buf.getByte(lastIndex).toInt().inv())
 
             assertFailsWith<IllegalArgumentException> {
-                Js5MasterIndex.read(buf, MasterIndexFormat.DIGESTS, PUBLIC_KEY)
+                Js5MasterIndex.read(buf.slice(), MasterIndexFormat.DIGESTS, PUBLIC_KEY)
             }
+
+            val index = Js5MasterIndex.readUnverified(buf, MasterIndexFormat.DIGESTS)
+            assertEquals(decodedWhirlpool, index)
         }
     }
 
@@ -278,8 +293,11 @@ class Js5MasterIndexTest {
     fun testReadSignedInvalidSignatureLength() {
         Unpooled.wrappedBuffer(encodedSigned, 0, encodedSigned.size - 1).use { buf ->
             assertFailsWith<IllegalArgumentException> {
-                Js5MasterIndex.read(buf, MasterIndexFormat.DIGESTS, PUBLIC_KEY)
+                Js5MasterIndex.read(buf.slice(), MasterIndexFormat.DIGESTS, PUBLIC_KEY)
             }
+
+            val index = Js5MasterIndex.readUnverified(buf, MasterIndexFormat.DIGESTS)
+            assertEquals(decodedWhirlpool, index)
         }
     }