fix: play song without loggin

reversed cna function for n and signature function, transpiled into kotlin

app/src/main/java/com/malopieds/innertune/playback/MusicService.kt

@@ -818,9 +818,19 @@ class MusicService :
                 )
             }
             scope.launch(Dispatchers.IO) { recoverSong(mediaId, playerResponse) }
+            val url =
+                run {
+                    runBlocking(Dispatchers.IO) {
+                        format.findUrl()
+                    }
+                }
 
-            songUrlCache[mediaId] = format.url!! to playerResponse.streamingData!!.expiresInSeconds * 1000L
-            dataSpec.withUri(format.url!!.toUri()).subrange(dataSpec.uriPositionOffset, CHUNK_LENGTH)
+            songUrlCache[mediaId] = url to (
+                playerResponse.streamingData?.expiresInSeconds?.times(
+                    1000L,
+                ) ?: 0
+            )
+            dataSpec.withUri(url.toUri()).subrange(dataSpec.uriPositionOffset, CHUNK_LENGTH)
         }
     }
 

innertube/src/main/java/com/malopieds/innertube/InnerTube.kt

@@ -12,8 +12,10 @@ import com.malopieds.innertube.models.body.GetTranscriptBody
 import com.malopieds.innertube.models.body.NextBody
 import com.malopieds.innertube.models.body.PlayerBody
 import com.malopieds.innertube.models.body.SearchBody
+import com.malopieds.innertube.utils.nSigDecode
 import com.malopieds.innertube.utils.parseCookieString
 import com.malopieds.innertube.utils.sha1
+import com.malopieds.innertube.utils.sigDecode
 import io.ktor.client.HttpClient
 import io.ktor.client.engine.okhttp.OkHttp
 import io.ktor.client.plugins.compression.ContentEncoding
@@ -26,7 +28,9 @@ import io.ktor.client.request.parameter
 import io.ktor.client.request.post
 import io.ktor.client.request.setBody
 import io.ktor.http.ContentType
+import io.ktor.http.URLBuilder
 import io.ktor.http.contentType
+import io.ktor.http.parseQueryString
 import io.ktor.http.userAgent
 import io.ktor.serialization.kotlinx.json.json
 import io.ktor.util.encodeBase64
@@ -269,4 +273,17 @@ class InnerTube {
             ytClient(client, setLogin = true)
             setBody(AccountMenuBody(client.toContext(locale, visitorData)))
         }
+
+    fun decodeCipher(cipher: String): String? {
+        val params = parseQueryString(cipher)
+        val signature = params["s"] ?: return null
+        val signatureParam = params["sp"] ?: return null
+        val url = params["url"]?.let { URLBuilder(it) } ?: return null
+        val n = url.parameters["n"]
+        url.parameters["n"] = nSigDecode(n.toString())
+        url.parameters[signatureParam] = sigDecode(signature)
+        url.parameters["c"] = "ANDROID_MUSIC"
+        println("url = $url")
+        return url.toString()
+    }
 }

innertube/src/main/java/com/malopieds/innertube/YouTube.kt

@@ -14,7 +14,7 @@ import com.malopieds.innertube.models.SongItem
 import com.malopieds.innertube.models.WatchEndpoint
 import com.malopieds.innertube.models.WatchEndpoint.WatchEndpointMusicSupportedConfigs.WatchEndpointMusicConfig.Companion.MUSIC_VIDEO_TYPE_ATV
 import com.malopieds.innertube.models.YouTubeClient.Companion.ANDROID_MUSIC
-import com.malopieds.innertube.models.YouTubeClient.Companion.TVHTML5
+import com.malopieds.innertube.models.YouTubeClient.Companion.IOS
 import com.malopieds.innertube.models.YouTubeClient.Companion.WEB
 import com.malopieds.innertube.models.YouTubeClient.Companion.WEB_REMIX
 import com.malopieds.innertube.models.YouTubeLocale
@@ -877,19 +877,30 @@ object YouTube {
                 }
         }
 
+    private val PlayerResponse.isValid
+        get() =
+            playabilityStatus.status == "OK" &&
+                streamingData?.adaptiveFormats?.any { it.url != null || it.signatureCipher != null } == true
+
     suspend fun player(
         videoId: String,
         playlistId: String? = null,
     ): Result<PlayerResponse> =
         runCatching {
-            val playerResponse = innerTube.player(ANDROID_MUSIC, videoId, playlistId).body<PlayerResponse>()
-            if (playerResponse.playabilityStatus.status == "OK") {
-                return@runCatching playerResponse
+            val safePlayerResponse = innerTube.player(WEB_REMIX, videoId, playlistId).body<PlayerResponse>()
+            if (safePlayerResponse.isValid) {
+                return@runCatching safePlayerResponse
             }
-            val safePlayerResponse = innerTube.player(TVHTML5, videoId, playlistId).body<PlayerResponse>()
-            if (safePlayerResponse.playabilityStatus.status != "OK") {
+            val playerResponse =
+                innerTube.player(IOS, videoId, playlistId).body<PlayerResponse>()
+            if (playerResponse.isValid) {
                 return@runCatching playerResponse
             }
+            val androidPlayerResponse =
+                innerTube.player(ANDROID_MUSIC, videoId, playlistId).body<PlayerResponse>()
+            if (androidPlayerResponse.playabilityStatus.status == "OK") {
+                return@runCatching androidPlayerResponse
+            }
             val audioStreams = innerTube.pipedStreams(videoId).body<PipedResponse>().audioStreams
             safePlayerResponse.copy(
                 streamingData =

innertube/src/main/java/com/malopieds/innertube/models/Context.kt

@@ -11,6 +11,7 @@ data class Context(
     data class Client(
         val clientName: String,
         val clientVersion: String,
+        val osVersion: String?,
         val gl: String,
         val hl: String,
         val visitorData: String?,

innertube/src/main/java/com/malopieds/innertube/models/YouTubeClient.kt

@@ -6,6 +6,7 @@ import kotlinx.serialization.Serializable
 data class YouTubeClient(
     val clientName: String,
     val clientVersion: String,
+    val osVersion: String? = null,
     val api_key: String,
     val userAgent: String,
     val referer: String? = null,
@@ -18,6 +19,7 @@ data class YouTubeClient(
             Context.Client(
                 clientName = clientName,
                 clientVersion = clientVersion,
+                osVersion = osVersion,
                 gl = locale.gl,
                 hl = locale.hl,
                 visitorData = visitorData,
@@ -29,11 +31,12 @@ data class YouTubeClient(
 
         private const val USER_AGENT_WEB = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.157 Safari/537.36"
         private const val USER_AGENT_ANDROID = "Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Mobile Safari/537.36"
+        const val USER_AGENT_IOS = "com.google.ios.youtube/19.29.1 (iPhone16,2; U; CPU iOS 17_5_1 like Mac OS X;)"
 
         val ANDROID_MUSIC =
             YouTubeClient(
                 clientName = "ANDROID_MUSIC",
-                clientVersion = "5.01",
+                clientVersion = "5.54.52",
                 api_key = "AIzaSyAOghZGza2MQSZkY_zfZ370N-PUdXEo8AI",
                 userAgent = USER_AGENT_ANDROID,
             )
@@ -45,7 +48,14 @@ data class YouTubeClient(
                 api_key = "AIzaSyA8eiZmM1FaDVjRy-df2KTyQ_vz_yYM39w",
                 userAgent = USER_AGENT_ANDROID,
             )
-
+        val IOS =
+            YouTubeClient(
+                clientName = "IOS",
+                clientVersion = "19.29.1",
+                osVersion = "17.5.1.21F90",
+                api_key = "AIzaSyB-63vPrdThhKuerbB2N_l7Kwwcxj6yUAc",
+                userAgent = USER_AGENT_IOS,
+            )
         val WEB =
             YouTubeClient(
                 clientName = "WEB",
@@ -57,7 +67,7 @@ data class YouTubeClient(
         val WEB_REMIX =
             YouTubeClient(
                 clientName = "WEB_REMIX",
-                clientVersion = "1.20220606.03.00",
+                clientVersion = "1.20241023.01.00",
                 api_key = "AIzaSyC9XL3ZjWddXya6X74dJoCTL-WEYFDNX30",
                 userAgent = USER_AGENT_WEB,
                 referer = REFERER_YOUTUBE_MUSIC,

innertube/src/main/java/com/malopieds/innertube/models/body/PlayerBody.kt

@@ -8,4 +8,16 @@ data class PlayerBody(
     val context: Context,
     val videoId: String,
     val playlistId: String?,
-)
+    val cpn: String? = "wzf9Y0nqz6AUe2Vr", // need some random cpn to get same algorithm for sig
+    val playbackContext: PlaybackContext? = PlaybackContext(ContentPlaybackContext(20019L)),
+) {
+    @Serializable
+    data class PlaybackContext(
+        val contentPlaybackContext: ContentPlaybackContext?,
+    )
+
+    @Serializable
+    data class ContentPlaybackContext(
+        val signatureTimestamp: Long?,
+    )
+}

innertube/src/main/java/com/malopieds/innertube/models/response/PlayerResponse.kt

@@ -1,5 +1,6 @@
 package com.malopieds.innertube.models.response
 
+import com.malopieds.innertube.InnerTube
 import com.malopieds.innertube.models.ResponseContext
 import com.malopieds.innertube.models.Thumbnails
 import kotlinx.serialization.Serializable
@@ -57,9 +58,12 @@ data class PlayerResponse(
             val audioChannels: Int?,
             val loudnessDb: Double?,
             val lastModified: Long?,
+            val signatureCipher: String?,
         ) {
             val isAudio: Boolean
                 get() = width == null
+
+            fun findUrl() = url ?: signatureCipher?.let { InnerTube().decodeCipher(it) }!!
         }
     }
 

innertube/src/main/java/com/malopieds/innertube/utils/Utils.kt

@@ -49,3 +49,69 @@ fun String.parseTime(): Int? {
     }
     return null
 }
+
+fun nSigDecode(n: String): String {
+    val step1 =
+        buildString {
+            append(n[8])
+            append(n.substring(2, 8))
+            append(n[1])
+            append(n.substring(9))
+        }
+
+    val step2 =
+        buildString {
+            append(step1.substring(7))
+            append((step1[0] + step1.substring(1, 3).reversed() + step1[3]).reversed())
+            append(step1.substring(4, 7))
+        }
+
+    val step3 = step2.substring(7) + step2.substring(0, 7)
+
+    val step4 =
+        buildString {
+            append(step3[step3.length - 4])
+            append(step3.substring(3, 7))
+            append(step3[2])
+            append(step3.substring(8, 11))
+            append(step3[7])
+            append(step3.takeLast(3))
+            append(step3[1])
+        }
+
+    val step5 = (step4.substring(0, 2) + step4.last() + step4.substring(3, step4.length - 1) + step4[2]).reversed()
+
+    val keyString = "cbrrC5"
+    val charset = ('A'..'Z') + ('a'..'z') + ('0'..'9') + listOf('-', '_')
+    val mutableKeyList = keyString.toMutableList()
+
+    val transformedChars = CharArray(step5.length)
+
+    for (index in step5.indices) {
+        val currentChar = step5[index]
+        val indexInCharset =
+            (charset.indexOf(currentChar) - charset.indexOf(mutableKeyList[index % mutableKeyList.size]) + index + charset.size - index) %
+                charset.size
+        transformedChars[index] = charset[indexInCharset]
+        mutableKeyList[index % mutableKeyList.size] = transformedChars[index]
+    }
+
+    val step6 = String(transformedChars)
+    return step6.dropLast(3).reversed() + step6.takeLast(3)
+}
+
+fun sigDecode(input: String): String {
+    val middleSection = input.substring(3, input.length - 3)
+    val rearranged = (middleSection.take(35) + input[0] + middleSection.drop(36)).reversed()
+    val result =
+        buildString {
+            append("A")
+            append(rearranged.substring(0, 15))
+            append(input[input.length - 2])
+            append(rearranged.substring(16, 34))
+            append(input[input.length - 3])
+            append(rearranged.substring(35))
+            append(input[38])
+        }
+    return result
+}