MangaGreat: Solve JS challenge (#17217)

* MangaGreat: Solve JS challenge

* wording

multisrc/overrides/madara/mangagreat/src/MangaGreat.kt

@@ -1,9 +1,126 @@
 package eu.kanade.tachiyomi.extension.en.mangagreat
 
+import android.util.Base64
+import app.cash.quickjs.QuickJs
 import eu.kanade.tachiyomi.multisrc.madara.Madara
+import eu.kanade.tachiyomi.util.asJsoup
+import okhttp3.Cookie
+import okhttp3.Interceptor
+import okhttp3.OkHttpClient
+import okhttp3.Response
+import java.io.IOException
+import javax.crypto.Cipher
+import javax.crypto.spec.IvParameterSpec
+import javax.crypto.spec.SecretKeySpec
 
 class MangaGreat : Madara("MangaGreat", "https://mangagreat.com", "en") {
+    override val client: OkHttpClient = super.client.newBuilder()
+        .addInterceptor(::JSChallengeInterceptor)
+        .build()
 
     // The website does not flag the content.
     override val filterNonMangaItems = false
+
+    // /manga/page/1/ redirects to /manga/
+    override fun searchPage(page: Int): String = if (page == 1) "" else "page/$page/"
+
+    //
+    // JS Challenge logic start
+    //
+    @Suppress("FunctionName")
+    private fun JSChallengeInterceptor(chain: Interceptor.Chain): Response {
+        val request = chain.request()
+        val response = chain.proceed(request)
+
+        if (response.code != 202) return response
+        val url = request.url
+
+        Cookie.parse(url, getJSChallengeCookie(response))
+            ?.let { client.cookieJar.saveFromResponse(url, listOf(it)) }
+            ?: throw IOException("Failed JavaScript challenge. Check WebView.")
+
+        return client.newCall(request).execute()
+    }
+
+    private fun getJSChallengeCookie(response: Response): String {
+        val document = response.asJsoup()
+
+        val jsPatch = ";function atob(a){return base64.atob(a)};document.cookie"
+        val jsPayload = document.select("script")
+            .joinToString("\n") { it.data() }
+            .trimIndent() + jsPatch
+
+        val fauxBase64 = FauxBase64()
+        val fauxLocation = FauxLocation()
+        val fauxDocument = FauxDocument()
+        val slowAES = FauxSlowAES()
+
+        QuickJs.create().use { context ->
+            context.set("base64", FauxBase64Interface::class.java, fauxBase64)
+            context.set("location", FauxLocationInterface::class.java, fauxLocation)
+            context.set("document", FauxDocumentInterface::class.java, fauxDocument)
+            context.set("slowAES", FauxSlowAESInterface::class.java, slowAES)
+
+            return context.evaluate(jsPayload) as String
+        }
+    }
+
+    class FauxBase64 : FauxBase64Interface {
+        override fun atob(base64: String): String {
+            return String(Base64.decode(base64, Base64.DEFAULT))
+        }
+    }
+
+    class FauxLocation : FauxLocationInterface {
+        override var href: String = ""
+    }
+
+    class FauxDocument : FauxDocumentInterface {
+        override var cookie: String = ""
+    }
+
+    class FauxSlowAES : FauxSlowAESInterface {
+        private fun Array<Int>.toByteArray(): ByteArray {
+            return map { it.toByte() }.toByteArray()
+        }
+
+        private fun ByteArray.toTypedArray(): Array<Int> {
+            return map { it.toInt() and 0xFF }.toTypedArray()
+        }
+
+        override fun decrypt(cipherIn: Array<Int>, mode: Int, key: Array<Int>, iv: Array<Int>): Array<Int> {
+            val modeStr = when (mode) {
+                0 -> "OFB"
+                1 -> "CFB"
+                else -> "CBC" // 2 = CBC, 3+ = unknown
+            }
+
+            val cipher = Cipher.getInstance("AES/$modeStr/NoPadding")
+            val keyS = SecretKeySpec(key.toByteArray(), "AES")
+            cipher.init(Cipher.DECRYPT_MODE, keyS, IvParameterSpec(iv.toByteArray()))
+
+            return cipher.doFinal(cipherIn.toByteArray()).toTypedArray()
+        }
+    }
+
+    interface FauxBase64Interface {
+        fun atob(base64: String): String
+    }
+
+    interface FauxLocationInterface {
+        val href: String
+    }
+
+    private interface FauxDocumentInterface {
+        val cookie: String
+    }
+
+    @Suppress("unused")
+    private interface FauxSlowAESInterface {
+        fun decrypt(cipherIn: Array<Int>, mode: Int, key: Array<Int>, iv: Array<Int>): Array<Int>
+    }
+
+    //
+    // JS Challenge logic end
+    //
 }

multisrc/src/main/java/eu/kanade/tachiyomi/multisrc/madara/MadaraGenerator.kt

@@ -237,7 +237,7 @@ class MadaraGenerator : ThemeSourceGenerator {
         SingleLang("MangaFoxFull", "https://mangafoxfull.com", "en"),
         SingleLang("MangaFreak.online", "https://mangafreak.online", "en", className = "MangaFreakOnline"),
         SingleLang("MangaGG", "https://mangagg.com", "en", overrideVersionCode = 2),
-        SingleLang("MangaGreat", "https://mangagreat.com", "en", overrideVersionCode = 3),
+        SingleLang("MangaGreat", "https://mangagreat.com", "en", overrideVersionCode = 4),
         SingleLang("MangaHub.fr", "https://mangahub.fr", "fr", isNsfw = true, className = "MangaHubFr", pkgName = "mangahubfr"),
         SingleLang("MangaHZ", "https://www.mangahz.com", "en", isNsfw = true, overrideVersionCode = 2),
         SingleLang("MangaK2", "https://mangak2.com", "en", isNsfw = true),