feat: implement smali patching

Apply the smali patch bundles while patching the APK

app/build.gradle.kts

@@ -137,7 +137,10 @@ dependencies {
     implementation(libs.bouncycastle)
     implementation(libs.binaryResources)
     implementation(libs.coil)
+    implementation(libs.diff)
     implementation(libs.microg)
+    implementation(libs.smali)
+    implementation(libs.baksmali)
     implementation(variantOf(libs.zip) { artifactType("aar") })
 }
 

app/src/main/kotlin/com/aliucord/manager/manager/PathManager.kt

@@ -2,6 +2,7 @@ package com.aliucord.manager.manager
 
 import android.content.Context
 import android.os.Environment
+import com.aliucord.manager.network.utils.SemVer
 import java.io.File
 
 /**
@@ -58,7 +59,7 @@ class PathManager(context: Context) {
     /**
      * Resolve a specific path for a cached injector.
      */
-    fun cachedInjectorDex(aliucordHash: String) = externalCacheDir
+    fun cachedInjectorDex(aliucordHash: SemVer) = externalCacheDir
         .resolve("injector").apply { mkdirs() }
         .resolve("$aliucordHash.dex")
 
@@ -69,6 +70,13 @@ class PathManager(context: Context) {
         .resolve("aliuhook").apply { mkdirs() }
         .resolve("$version.aar")
 
+    /**
+     * Resolve a specific path for a versioned smali patches archive.
+     */
+    fun cachedSmaliPatches(version: SemVer) = externalCacheDir
+        .resolve("patches").apply { mkdirs() }
+        .resolve("$version.zip")
+
     /**
      * Singular Kotlin file of the most up-to-date version
      * since the stdlib is backwards compatible.

app/src/main/kotlin/com/aliucord/manager/network/utils/SemVer.kt

@@ -1,5 +1,6 @@
 package com.aliucord.manager.network.utils
 
+import androidx.compose.runtime.Immutable
 import kotlinx.serialization.KSerializer
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.descriptors.PrimitiveKind
@@ -10,6 +11,7 @@ import kotlinx.serialization.encoding.Encoder
 /**
  * Parses a Semantic version in the format of `v1.0.0` (v[major].[minor].[patch])
  */
+@Immutable
 @Serializable(SemVer.Serializer::class)
 data class SemVer(
     val major: Int,

app/src/main/kotlin/com/aliucord/manager/patcher/InstallMetadata.kt

@@ -33,4 +33,9 @@ data class InstallMetadata(
      * Version of the injector build that was injected into the APK.
      */
     val injectorVersion: SemVer,
+
+    /**
+     * Version of the smali patches that were applied onto the APK.
+     */
+    val patchesVersion: SemVer,
 )

app/src/main/kotlin/com/aliucord/manager/patcher/KotlinPatchRunner.kt

@@ -22,9 +22,11 @@ class KotlinPatchRunner(options: PatchOptions) : StepRunner() {
         DownloadInjectorStep(),
         DownloadAliuhookStep(),
         DownloadKotlinStep(),
+        DownloadPatchesStep(),
         CopyDependenciesStep(),
 
         // Patch
+        SmaliPatchStep(),
         ReplaceIconStep(options),
         PatchManifestStep(options),
         ReorganizeDexStep(),

app/src/main/kotlin/com/aliucord/manager/patcher/steps/base/DownloadStep.kt

@@ -83,6 +83,7 @@ abstract class DownloadStep : Step(), KoinComponent {
                         context.showToast(R.string.installer_dl_verify_fail)
                     }
 
+                    targetFile.delete()
                     throw t
                 }
             }

app/src/main/kotlin/com/aliucord/manager/patcher/steps/download/DownloadInjectorStep.kt

@@ -3,6 +3,7 @@ package com.aliucord.manager.patcher.steps.download
 import androidx.compose.runtime.Stable
 import com.aliucord.manager.R
 import com.aliucord.manager.manager.PathManager
+import com.aliucord.manager.network.utils.SemVer
 import com.aliucord.manager.patcher.StepRunner
 import com.aliucord.manager.patcher.steps.base.DownloadStep
 import com.aliucord.manager.patcher.steps.base.IDexProvider
@@ -22,7 +23,7 @@ class DownloadInjectorStep : DownloadStep(), IDexProvider, KoinComponent {
     /**
      * This is populated right before the download starts (ref: [execute])
      */
-    lateinit var targetVersion: String
+    lateinit var targetVersion: SemVer
         private set
 
     override val localizedName = R.string.patch_step_dl_injector
@@ -32,7 +33,7 @@ class DownloadInjectorStep : DownloadStep(), IDexProvider, KoinComponent {
 
     override suspend fun execute(container: StepRunner) {
         targetVersion = container.getStep<FetchInfoStep>()
-            .data.injectorVersion.toString()
+            .data.injectorVersion
 
         super.execute(container)
     }

app/src/main/kotlin/com/aliucord/manager/patcher/steps/download/DownloadPatchesStep.kt

@@ -0,0 +1,45 @@
+package com.aliucord.manager.patcher.steps.download
+
+import androidx.compose.runtime.Stable
+import com.aliucord.manager.R
+import com.aliucord.manager.manager.OverlayManager
+import com.aliucord.manager.manager.PathManager
+import com.aliucord.manager.network.utils.SemVer
+import com.aliucord.manager.patcher.StepRunner
+import com.aliucord.manager.patcher.steps.base.DownloadStep
+import com.aliucord.manager.patcher.steps.prepare.FetchInfoStep
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
+
+/**
+ * Download a zip of all the smali patches to be applied to the APK during patching.
+ */
+@Stable
+class DownloadPatchesStep : DownloadStep(), KoinComponent {
+    private val paths: PathManager by inject()
+    private val overlays: OverlayManager by inject()
+
+    /**
+     * This is populated right before the download starts (ref: [execute])
+     */
+    lateinit var targetVersion: SemVer
+        private set
+
+    override val localizedName = R.string.patch_step_dl_smali
+    override val targetUrl get() = URL
+    override val targetFile get() = paths.cachedSmaliPatches(targetVersion)
+
+    override suspend fun execute(container: StepRunner) {
+        targetVersion = container.getStep<FetchInfoStep>()
+            .data.patchesVersion
+
+        super.execute(container)
+    }
+
+    private companion object {
+        const val ORG = "Aliucord"
+        const val MAIN_REPO = "Aliucord"
+
+        const val URL = "https://raw.githubusercontent.com/$ORG/$MAIN_REPO/builds/patches.zip"
+    }
+}

app/src/main/kotlin/com/aliucord/manager/patcher/steps/patch/SaveMetadataStep.kt

@@ -31,13 +31,15 @@ class SaveMetadataStep(private val options: PatchOptions) : Step() {
         val apk = container.getStep<CopyDependenciesStep>().patchedApk
         val aliuhook = container.getStep<DownloadAliuhookStep>()
         val injector = container.getStep<DownloadInjectorStep>()
+        val patches = container.getStep<DownloadPatchesStep>()
 
         val metadata = InstallMetadata(
             options = options,
             customManager = IS_CUSTOM_BUILD,
             managerVersion = SemVer.parse(BuildConfig.VERSION_NAME),
             aliuhookVersion = aliuhook.targetVersion,
-            injectorVersion = SemVer.parse(injector.targetVersion),
+            injectorVersion = injector.targetVersion,
+            patchesVersion = patches.targetVersion,
         )
 
         ZipWriter(apk, /* append = */ true).use {

app/src/main/kotlin/com/aliucord/manager/patcher/steps/patch/SmaliPatchStep.kt

@@ -0,0 +1,129 @@
+package com.aliucord.manager.patcher.steps.patch
+
+import com.aliucord.manager.R
+import com.aliucord.manager.manager.PathManager
+import com.aliucord.manager.patcher.StepRunner
+import com.aliucord.manager.patcher.steps.StepGroup
+import com.aliucord.manager.patcher.steps.base.IDexProvider
+import com.aliucord.manager.patcher.steps.base.Step
+import com.aliucord.manager.patcher.steps.download.CopyDependenciesStep
+import com.aliucord.manager.patcher.steps.download.DownloadPatchesStep
+import com.android.tools.smali.baksmali.Baksmali
+import com.android.tools.smali.baksmali.BaksmaliOptions
+import com.android.tools.smali.dexlib2.Opcodes
+import com.android.tools.smali.dexlib2.dexbacked.DexBackedDexFile
+import com.android.tools.smali.smali.Smali
+import com.android.tools.smali.smali.SmaliOptions
+import com.github.diamondminer88.zip.ZipReader
+import com.github.difflib.DiffUtils
+import com.github.difflib.UnifiedDiffUtils
+import com.github.difflib.patch.Patch
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
+import java.io.FileNotFoundException
+import kotlin.io.path.Path
+import kotlin.io.path.writeLines
+
+class SmaliPatchStep : Step(), IDexProvider, KoinComponent {
+    private val paths: PathManager by inject()
+
+    override val group = StepGroup.Patch
+    override val localizedName = R.string.patch_step_patch_smali
+
+    private val coreCount = Runtime.getRuntime().availableProcessors()
+    private val smaliDir = paths.patchingWorkingDir().resolve("smali")
+    private val outDex = smaliDir.resolve("patched.dex")
+
+    override suspend fun execute(container: StepRunner) {
+        val apk = container.getStep<CopyDependenciesStep>().patchedApk
+        val patchesZip = container.getStep<DownloadPatchesStep>().targetFile
+
+        val patches = mutableListOf<LoadedPatch>()
+
+        // Load and parse all the patches from the smali patch archive
+        ZipReader(patchesZip).use { zip ->
+            for (patchFile in zip.entryNames) {
+                if (!patchFile.endsWith(".patch")) continue
+
+                val lines = zip.openEntry(patchFile)!!.read()
+                    .decodeToString()
+                    .split('\n')
+
+                try {
+                    val patch = LoadedPatch(
+                        fullClassName = patchFile.removeSuffix(".patch"),
+                        patch = UnifiedDiffUtils.parseUnifiedDiff(lines),
+                    )
+                    patches.add(patch)
+                } catch (t: Throwable) {
+                    throw Error("Failed to parse patch file $patchFile", t)
+                }
+            }
+        }
+
+        // Disassemble all the classes we have patches for from all the dex files
+        ZipReader(apk).use { zip ->
+            for (file in zip.entryNames) {
+                if (!file.endsWith(".dex")) continue
+
+                val dexFile = try {
+                    DexBackedDexFile(
+                        /* opcodes = */ Opcodes.getDefault(),
+                        /* buf = */ zip.openEntry(file)!!.read(),
+                    )
+                } catch (t: Throwable) {
+                    throw Error("Failed to parse dex $file", t)
+                }
+
+                val result = try {
+                    Baksmali.disassembleDexFile(
+                        /* dexFile = */ dexFile,
+                        /* outputDir = */ smaliDir,
+                        /* jobs = */ coreCount - 1,
+                        /* options = */ BaksmaliOptions(),
+                        /* classes = */ patches.map { "L${it.fullClassName};" },
+                    )
+                } catch (t: Throwable) {
+                    throw Error("Failed to disassemble dex $file", t)
+                }
+
+                assert(result) { "Failed to disassemble dex $file (unknown reason)" }
+            }
+        }
+
+        // Apply all the patches to the smali files
+        for ((fullClassName, patch) in patches) {
+            val smaliFile = smaliDir.resolve("$fullClassName.smali")
+            if (!smaliFile.exists()) {
+                throw FileNotFoundException("Target smali file $fullClassName.smali not found for patching!")
+            }
+
+            val patched = try {
+                DiffUtils.patch(smaliFile.readText().split('\n'), patch)
+            } catch (t: Throwable) {
+                throw Error("Failed to smali patch $fullClassName", t)
+            }
+
+            Path(smaliFile.absolutePath).writeLines(patched)
+        }
+
+        // Assemble the patched classes back into a single dex
+        smaliDir.mkdir()
+        Smali.assemble(
+            SmaliOptions().apply {
+                this.jobs = coreCount - 1
+                this.outputDexFile = outDex.absolutePath
+            },
+            listOf(smaliDir.absolutePath),
+        )
+    }
+
+    override val dexPriority = 2
+    override val dexCount = 1
+    override fun getDexFiles() = listOf(outDex.readBytes())
+}
+
+private data class LoadedPatch(
+    val fullClassName: String,
+    val patch: Patch<String>,
+)

app/src/main/res/values/strings.xml

@@ -109,11 +109,13 @@
   <string name="patch_step_dl_kotlin">Downloading Kotlin Stdlib</string>
   <string name="patch_step_dl_injector">Downloading Aliucord Injector</string>
   <string name="patch_step_dl_aliuhook">Downloading Aliuhook library</string>
+  <string name="patch_step_dl_smali">Downloading smali patches</string>
   <string name="patch_step_copy_deps">Copying dependencies</string>
   <string name="patch_step_patch_manifests">Patching apk manifests</string>
   <string name="patch_step_patch_icon">Patching app icon</string>
   <string name="patch_step_add_injector">Adding Aliucord injector</string>
   <string name="patch_step_add_aliuhook">Adding Aliuhook library</string>
+  <string name="patch_step_patch_smali">Applying smali patches</string>
   <string name="patch_step_reorganize_dex">Adding .dex files to APK</string>
   <string name="patch_step_save_metadata">Store metadata</string>
   <string name="patch_step_alignment">Aligning APKs</string>

gradle/libs.versions.toml

@@ -14,12 +14,14 @@ compose = "1.5.4"
 compose-compiler = "1.5.8"
 compose-tracing = "1.0.0-beta01"
 compose-material3 = "1.2.0-rc01"
+diff = "4.12"
 koin = "3.5.3"
 kotlin = "1.9.22"
 kotlinx-immutable = "0.3.7"
 kotlinx-serialization = "1.5.0"
 ktor = "2.3.7"
 microg = "0.3.2.240913"
+smali = "3.0.7"
 voyager = "1.0.0"
 zip = "2.1.1"
 
@@ -73,7 +75,10 @@ axml = { module = "com.aliucord:axml", version.ref = "axml" }
 binaryResources = { module = "com.aliucord:binary-resources", version.ref = "binary-resources" }
 bouncycastle = { module = "org.bouncycastle:bcpkix-jdk15on", version.ref = "bouncycastle" }
 coil = { module = "io.coil-kt:coil-compose", version.ref = "coil" }
+diff = { module = "io.github.java-diff-utils:java-diff-utils", version.ref = "diff" }
 microg = { module = "org.microg.gms:play-services-safetynet", version.ref = "microg" }
+smali = { module = "com.android.tools.smali:smali", version.ref = "smali" }
+baksmali = { module = "com.android.tools.smali:smali-baksmali", version.ref = "smali" }
 zip = { module = "io.github.diamondminer88:zip-android", version.ref = "zip" } # Only use the "aar" artifact
 
 [bundles]