Panels Dex Utils

src/main/kotlin/dev/frozenmilk/sinister/DexUsageExample.kt

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+package dev.frozenmilk.sinister
+
+import android.content.Context
+import java.nio.ByteBuffer
+import java.nio.ByteOrder
+import java.util.zip.ZipFile
+
+object DexUsageExample {
+    fun load(context: Context) {
+        val apkPath =  context.packageCodePath
+        try {
+            ZipFile(apkPath).use { zipFile ->
+                val entries = zipFile.entries()
+                while (entries.hasMoreElements()) {
+                    val entry = entries.nextElement()
+                    if (entry.name.startsWith("classes") && entry.name.endsWith(".dex")) { //app has multiple dex files
+                        zipFile.getInputStream(entry).use { inputStream ->
+                            val dexBytes = inputStream.readBytes()
+                            val dexBuffer =
+                                ByteBuffer.wrap(dexBytes).order(ByteOrder.LITTLE_ENDIAN)
+                            val classNames = dexBuffer.extractClassNamesFromDex()
+
+                            //TODO do something with classes
+                        }
+                    }
+                }
+            }
+        } catch (t: Throwable) {
+            // handle errors
+        }
+    }
+}

src/main/kotlin/dev/frozenmilk/sinister/DexUtils.kt

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+package dev.frozenmilk.sinister
+
+import java.nio.ByteBuffer
+
+fun ByteBuffer.extractClassNamesFromDex(): List<String> {
+    val classNames = ArrayList<String>()
+
+    this.position(0)
+
+    // Check DEX magic and version
+    val magic = ByteArray(8)
+    this.get(magic)
+    val magicString = String(magic)
+    if (!magicString.startsWith("dex\n") || magicString.length < 8) {
+        throw IllegalArgumentException("Invalid DEX magic: $magicString")
+    }
+
+    // Read header values with proper unsigned handling
+    this.position(32)
+    val fileSize = this.getInt().toLong() and 0xFFFFFFFFL
+
+    this.position(36)
+    val headerSize = this.getInt().toLong() and 0xFFFFFFFFL
+
+    this.position(56)
+    val stringIdsSize = this.getInt().toLong() and 0xFFFFFFFFL
+    val stringIdsOffset = this.getInt().toLong() and 0xFFFFFFFFL
+
+    this.position(64)
+    val typeIdsSize = this.getInt().toLong() and 0xFFFFFFFFL
+    val typeIdsOffset = this.getInt().toLong() and 0xFFFFFFFFL
+
+    // Validate sizes and offsets
+    if (stringIdsSize <= 0 || typeIdsSize <= 0 ||
+        stringIdsOffset < headerSize || typeIdsOffset < headerSize ||
+        stringIdsOffset > fileSize || typeIdsOffset > fileSize
+    ) {
+        throw IllegalArgumentException("Invalid table sizes or offsets: stringIdsSize=$stringIdsSize, typeIdsSize=$typeIdsSize, stringIdsOffset=$stringIdsOffset, typeIdsOffset=$typeIdsOffset")
+    }
+
+    // Read string offsets
+    this.position(stringIdsOffset.toInt())
+    val stringOffsets = LongArray(stringIdsSize.toInt())
+    for (i in 0 until stringIdsSize.toInt()) {
+        stringOffsets[i] = this.getInt().toLong() and 0xFFFFFFFFL
+    }
+
+    // Extract class names
+    this.position(typeIdsOffset.toInt())
+    for (i in 0 until typeIdsSize.toInt()) {
+        val stringIndex = this.getInt().toLong() and 0xFFFFFFFFL
+        if (stringIndex >= stringIdsSize) continue
+
+        val stringOffset = stringOffsets[stringIndex.toInt()]
+        val originalPosition = this.position()
+
+        try {
+            this.position(stringOffset.toInt())
+            val length = readUleb128(this)
+            if (length > 1024) continue // Sanity check
+
+            val stringBytes = ByteArray(length)
+            this.get(stringBytes)
+            val classDescriptor = String(stringBytes)
+
+            if (classDescriptor.startsWith("L") && classDescriptor.endsWith(";")) {
+                val className = classDescriptor
+                    .substring(1, classDescriptor.length - 1)
+                    .replace('/', '.')
+                classNames.add(className)
+            }
+        } catch (e: Exception) {
+            throw e //TODO: handle errors, panels used it's own logger here
+        } finally {
+            this.position(originalPosition)
+        }
+    }
+
+    return classNames
+}
+
+private fun readUleb128(buffer: ByteBuffer): Int {
+    var result = 0
+    var shift = 0
+    var byte: Int
+
+    do {
+        byte = buffer.get().toInt() and 0xFF
+        result = result or ((byte and 0x7F) shl shift)
+        shift += 7
+    } while (byte and 0x80 != 0 && shift < 35) // Prevent infinite loop
+
+    return result
+}