Initial commit

bl-core/build.gradle.kts

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+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+
+plugins {
+    kotlin("multiplatform")
+    kotlin("plugin.serialization")
+}
+
+kotlin {
+    explicitApi()
+
+    linuxX64()
+    linuxArm64()
+    macosArm64()
+    mingwX64()
+    jvm { compilerOptions.jvmTarget = JvmTarget.JVM_11 }
+
+    sourceSets {
+        commonMain.dependencies {
+            api("org.jetbrains.kotlinx:kotlinx-serialization-json:1.11.0")
+            api("org.kotlincrypto.hash:md:0.8.0")
+            api("org.jetbrains.kotlinx:kotlinx-io-core:0.9.1")
+        }
+
+        commonTest.dependencies {
+            implementation(kotlin("test"))
+            implementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.11.0")
+        }
+    }
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/constant.kt

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+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/29
+ */
+
+package cn.rtast.bldm.core
+
+public const val REAL_ROOM_ID_URL: String = "https://api.live.bilibili.com/room/v1/Room/room_init?id="
+public const val DM_SERVER_CONF_URL: String = "https://api.live.bilibili.com/xlive/web-room/v1/index/getDanmuInfo?id="
+public const val USER_NAV_URL: String = "https://api.bilibili.com/x/web-interface/nav"

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/data/DMServerConf.kt

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+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/29
+ */
+
+
+package cn.rtast.bldm.core.data
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.Transient
+
+@Serializable
+public data class DMServerConf(
+    val data: ServerConf,
+) {
+    @Serializable
+    public data class ServerConf(
+        val token: String,
+        @SerialName("host_list")
+        val hostList: List<ServerHost>,
+    )
+
+    @Serializable
+    public data class ServerHost(
+        val host: String,
+        val port: Int,
+        @SerialName("wss_port")
+        val wssPort: Int,
+        @SerialName("ws_port")
+        val wsPort: Int,
+    )
+
+    @Transient
+    public val defaultServerHost: ServerHost = ServerHost("broadcastlv.chat.bilibili.com", 2243, 2245, 2244)
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/data/RealRoomId.kt

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+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/29
+ */
+
+
+package cn.rtast.bldm.core.data
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+public data class RealRoomId(
+    val data: RoomId
+) {
+    @Serializable
+    public data class RoomId(
+        @SerialName("room_id")
+        val roomId: Long
+    )
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/data/UserNavData.kt

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+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+@file:OptIn(ExperimentalUnsignedTypes::class)
+
+package cn.rtast.bldm.core.data
+
+import cn.rtast.bldm.core.util.digest
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlin.time.Clock
+
+@Serializable
+public data class UserNavData(
+    @SerialName("wbi_img")
+    val wbiImg: WbiImg,
+) {
+    @Serializable
+    public data class WbiImg(
+        @SerialName("img_url")
+        val imgUrl: String,
+        @SerialName("sub_url")
+        val subUrl: String,
+    )
+
+    private companion object {
+        val MIXIN_KEY_ENC_TAB = intArrayOf(
+            46, 47, 18, 2, 53, 8, 23, 32, 15, 50, 10, 31, 58, 3, 45, 35, 27, 43, 5, 49,
+            33, 9, 42, 19, 29, 28, 14, 39, 12, 38, 41, 13, 37, 48, 7, 16, 24, 55, 40,
+            61, 26, 17, 0, 1, 60, 51, 30, 4, 22, 25, 54, 21, 56, 59, 6, 63, 57, 62, 11,
+            36, 20, 34, 44, 52
+        )
+
+        fun String.encodeURIComponent(): String {
+            val bytes = this.encodeToByteArray()
+            val sb = StringBuilder()
+            for (b in bytes) {
+                val c = b.toInt().and(0xFF).toChar()
+                if (c in 'A'..'Z' || c in 'a'..'z' || c in '0'..'9' || c == '-' || c == '_' || c == '.' || c == '~') {
+                    sb.append(c)
+                } else {
+                    val hex = (b.toInt() and 0xFF).toString(16).uppercase()
+                    sb.append('%')
+                    if (hex.length == 1) sb.append('0')
+                    sb.append(hex)
+                }
+            }
+            return sb.toString()
+        }
+
+        fun Map<String, Any?>.toQueryString(): String {
+            return this.mapNotNull { (key, value) ->
+                if (value != null) {
+                    "${key.encodeURIComponent()}=${value.toString().encodeURIComponent()}"
+                } else {
+                    null
+                }
+            }.joinToString("&")
+        }
+    }
+
+    /**
+     * get resorted mixin key
+     */
+    private fun getMixinKey(): String =
+        (wbiImg.imgUrl.substringAfterLast('/').removeSuffix(".png") +
+                wbiImg.subUrl.substringAfterLast('/').removeSuffix(".png")).let { s ->
+            buildString { repeat(32) { append(s[MIXIN_KEY_ENC_TAB[it]]) } }
+        }
+
+    public fun signWbi(room: Long): String {
+//        val payload = _wbi_sign_payload(room, 0, Clock.System.now().epochSeconds)  // ref
+        val wts = Clock.System.now().epochSeconds
+        val params = mapOf("id" to room, "type" to 0)
+            .entries.sortedBy { it.key }.associate { it.key to it.value }.toMutableMap()
+        return buildString {
+            append(params.toQueryString())
+            params["wts"] = wts
+            append("&wts=$wts")
+            append("&w_rid=${(params.toQueryString() + getMixinKey()).digest()}")
+        }
+    }
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/data/_wbi_sign_payload.kt

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+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.data
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+@Suppress("ClassName")
+internal data class _wbi_sign_payload(
+    /**
+     * room id
+     */
+    val id: Long,
+    /**
+     * always be 0
+     */
+    val type: Int,
+    /**
+     * current unix timestamp (seconds)
+     */
+    val wts: Long
+)

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/data/protocol/AuthPayload.kt

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+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.data.protocol
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+internal data class AuthPayload(
+    /**
+     * user id
+     */
+    val uid: Int,
+    /**
+     * room id
+     */
+    val roomid: Long,
+    /**
+     * protocol version
+     * always be 2
+     */
+    val protover: Int,
+    /**
+     * device id
+     */
+    val buvid: String,
+    /**
+     * platform always be "web"
+     */
+    val platform: String,
+    /**
+     * always be 2
+     */
+    val type: Int,
+    /**
+     * token
+     */
+    val key: String
+)

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/protocol/Packet.kt

@@ -0,0 +1,83 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.protocol
+
+import kotlinx.io.Buffer
+import kotlinx.io.readByteArray
+
+/**
+ * packet header 16 bytes length + body (variant length)
+ */
+public data class Packet(
+    /**
+     * total packet length
+     * 4 bytes
+     */
+    val packetLength: Int = -1,
+    /**
+     * always 16
+     * 2 bytes
+     */
+    val headerLength: Short = 16,
+    /**
+     * protocol = 1
+     * 2 bytes
+     */
+    val protocolVersion: Short = 1,
+    /**
+     * packet type
+     * 4 bytes
+     */
+    val packetType: Int,
+    /**
+     * packet sequence
+     * value is usually 1
+     * 4 bytes
+     */
+    val sequence: Int = 1,
+    /**
+     * packet body
+     * variant length
+     */
+    val body: ByteArray,
+) {
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other == null || this::class != other::class) return false
+
+        other as Packet
+
+        if (packetLength != other.packetLength) return false
+        if (headerLength != other.headerLength) return false
+        if (protocolVersion != other.protocolVersion) return false
+        if (packetType != other.packetType) return false
+        if (sequence != other.sequence) return false
+        if (!body.contentEquals(other.body)) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        var result = packetLength
+        result = 31 * result + headerLength
+        result = 31 * result + protocolVersion
+        result = 31 * result + packetType
+        result = 31 * result + sequence
+        result = 31 * result + body.contentHashCode()
+        return result
+    }
+
+    public fun toByteArray(): ByteArray = Buffer().apply {
+        writeInt(16 + body.size)
+        writeShort(headerLength)
+        writeShort(protocolVersion)
+        writeInt(packetType)
+        writeInt(sequence)
+        write(body, body.size)
+    }.readByteArray()
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/protocol/PacketDecoder.kt

@@ -0,0 +1,11 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.protocol
+
+class PacketDecoder {
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/protocol/PacketEncoder.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.protocol
+
+import cn.rtast.bldm.core.data.protocol.AuthPayload
+import cn.rtast.bldm.core.util.AutoIncrementInt
+import cn.rtast.bldm.core.util.encodeJson
+
+public class PacketEncoder {
+    public companion object {
+        private val HEARTBEAT_BODY: ByteArray = "[Object object]".encodeToByteArray()
+    }
+
+    private val _sequence by AutoIncrementInt()
+
+    public fun authPacket(uid: Int, roomId: Long, buvid: String, token: String): Packet {
+        val payload = AuthPayload(uid, roomId, 2, buvid, "web", 2, token)
+            .encodeJson().encodeToByteArray()
+        return Packet(packetType = PacketType.AUTH, sequence = _sequence, body = payload)
+    }
+
+    public fun heartbeatPacket(): Packet = Packet(packetType = 2, sequence = _sequence, body = HEARTBEAT_BODY)
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/protocol/PacketType.kt

@@ -0,0 +1,18 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.protocol
+
+public object PacketType {
+    public const val AUTH: Int = 7
+    public const val AUTH_REPLY: Int = 8
+    public const val HEARTBEAT: Int = 2
+    public const val HANDSHAKE_REPLY: Int = 1
+    public const val HEARTBEAT_REPLY: Int = 3
+    public const val SEND_MSG_REPLY: Int = 5
+    // TODO
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/util/AutoIncrementInt.kt

@@ -0,0 +1,18 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.util
+
+import kotlin.reflect.KProperty
+
+internal class AutoIncrementInt(initialValue: Int = 1) {
+    private var count = initialValue
+
+    operator fun getValue(thisRef: Any?, property: KProperty<*>): Int {
+        return ++count
+    }
+}

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/util/_md5.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.util
+
+import org.kotlincrypto.hash.md.MD5
+
+internal val md5Instance = MD5()
+
+internal fun String.digest(): String = md5Instance.digest(this.encodeToByteArray()).toHexString()

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/util/json.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.util
+
+import kotlinx.serialization.json.Json
+
+internal inline fun <reified T> String.fromJson(): T = Json.decodeFromString(this)
+
+internal inline fun <reified T> T.encodeJson(): String = Json.encodeToString(this)

bl-core/src/commonMain/kotlin/cn/rtast/bldm/core/util/zlib.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.util
+
+internal expect fun ByteArray.zlibDecompress(): ByteArray

bl-core/src/commonTest/kotlin/test/TestMd5.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package test
+
+import org.kotlincrypto.hash.md.MD5
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class TestMd5 {
+
+    @Test
+    fun `test md5`() {
+        val target = "e10adc3949ba59abbe56e057f20f883e"  // 123456
+
+        val res = MD5().digest("123456".encodeToByteArray()).toHexString()
+
+        assertEquals(target, res)
+    }
+}

bl-core/src/commonTest/kotlin/test/TestWbiSign.kt

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+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package test
+
+import cn.rtast.bldm.core.data.UserNavData
+import kotlin.test.Test
+
+class TestWbiSign {
+
+    @Test
+    fun `test wbi sign`() {
+        val imgUrl = "https://i0.hdslb.com/bfs/wbi/7cd084941338484aae1ad9425b84077c.png"
+        val subUrl = "https://i0.hdslb.com/bfs/wbi/4932caff0ff746eab6f01bf08b70ac45.png"
+        val signWbi = UserNavData(UserNavData.WbiImg(imgUrl, subUrl)).signWbi(27245513)
+        println(signWbi)
+    }
+}

bl-core/src/jvmMain/kotlin/cn/rtast/bldm/core/util/zlib.jvm.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+package cn.rtast.bldm.core.util
+
+import java.io.ByteArrayOutputStream
+import java.util.zip.Inflater
+
+public actual fun ByteArray.zlibDecompress(): ByteArray {
+    val inflater = Inflater(true)
+    val outputStream = ByteArrayOutputStream(this.size)
+    val buffer = ByteArray(1024)
+    inflater.setInput(this)
+    while (!inflater.finished()) {
+        val length = inflater.inflate(buffer)
+        if (length > 0) outputStream.write(buffer, 0, length)
+    }
+    inflater.end()
+    return outputStream.toByteArray()
+}

bl-core/src/nativeMain/kotlin/cn/rtast/bldm/core/util/zlib.native.kt

@@ -0,0 +1,61 @@
+/*
+ * Copyright © 2026 RTAkland
+ * Author: RTAkland
+ * Date: 2026/8/30
+ */
+
+
+@file:OptIn(ExperimentalForeignApi::class)
+
+package cn.rtast.bldm.core.util
+
+import kotlinx.cinterop.*
+import platform.zlib.*
+
+private const val MAX_WBITS = 15
+
+public actual fun ByteArray.zlibDecompress(): ByteArray {
+    if (isEmpty()) return ByteArray(0)
+    return memScoped {
+        val stream = alloc<z_stream>()
+        stream.zalloc = null
+        stream.zfree = null
+        stream.opaque = null
+        check(inflateInit2_(stream.ptr, MAX_WBITS, ZLIB_VERSION, sizeOf<z_stream>().toInt()) == Z_OK) { "inflateInit2_ failed" }
+
+        val inputPinned = this@zlibDecompress.pin()
+        try {
+            stream.next_in = inputPinned.addressOf(0).reinterpret()
+            stream.avail_in = this@zlibDecompress.size.toUInt()
+
+            val bufferSize = 4096
+            val tempBuffer = ByteArray(bufferSize)
+            val tempPinned = tempBuffer.pin()
+            val output = ArrayList<Byte>(this@zlibDecompress.size * 2)
+
+            try {
+                do {
+                    stream.next_out = tempPinned.addressOf(0).reinterpret()
+                    stream.avail_out = bufferSize.toUInt()
+
+                    val result = inflate(stream.ptr, Z_NO_FLUSH)
+                    check(result == Z_OK || result == Z_STREAM_END) { "inflate error: $result" }
+
+                    val bytesDecompressed = bufferSize - stream.avail_out.toInt()
+                    for (i in 0 until bytesDecompressed) {
+                        output.add(tempBuffer[i])
+                    }
+
+                    if (result == Z_STREAM_END) break
+                } while (stream.avail_out == 0u)
+            } finally {
+                tempPinned.unpin()
+            }
+
+            inflateEnd(stream.ptr)
+            return@memScoped output.toByteArray()
+        } finally {
+            inputPinned.unpin()
+        }
+    }
+}