From e70e8088ad592b4683192bc45ac8f9045c6302d8 Mon Sep 17 00:00:00 2001
From: vvb2060 <vvb2060@gmail.com>
Date: Tue, 14 Apr 2026 01:26:05 -0700
Subject: [PATCH] app: support download image and patch 1/2

---
 .../topjohnwu/magisk/dialog/DownloadDialog.kt |  59 +++
 .../magisk/ui/flash/FlashFragment.kt          |   7 +
 .../magisk/ui/flash/FlashViewModel.kt         |   8 +
 .../magisk/ui/install/InstallViewModel.kt     |   5 +
 .../main/res/layout/fragment_install_md2.xml  |  10 +-
 app/core/build.gradle.kts                     |  20 +
 app/core/proguard-rules.pro                   |   3 +
 .../java/com/topjohnwu/magisk/core/Const.kt   |   1 +
 .../magisk/core/tasks/MagiskInstaller.kt      |  64 +++
 .../magisk/core/utils/MediaStoreUtils.kt      |   2 +
 app/core/src/main/proto/update_metadata.proto | 445 ++++++++++++++++++
 app/core/src/main/res/values/strings.xml      |   3 +
 app/gradle.properties                         |   1 +
 app/gradle/libs.versions.toml                 |   5 +
 14 files changed, 632 insertions(+), 1 deletion(-)
 create mode 100644 app/apk/src/main/java/com/topjohnwu/magisk/dialog/DownloadDialog.kt
 create mode 100644 app/core/src/main/proto/update_metadata.proto

diff --git a/app/apk/src/main/java/com/topjohnwu/magisk/dialog/DownloadDialog.kt b/app/apk/src/main/java/com/topjohnwu/magisk/dialog/DownloadDialog.kt
new file mode 100644
index 000000000..d8d48f6f2
--- /dev/null
+++ b/app/apk/src/main/java/com/topjohnwu/magisk/dialog/DownloadDialog.kt
@@ -0,0 +1,59 @@
+package com.topjohnwu.magisk.dialog
+
+import android.net.Uri
+import android.text.InputType
+import android.widget.EditText
+import androidx.core.net.toUri
+import com.topjohnwu.magisk.core.R
+import com.topjohnwu.magisk.events.DialogBuilder
+import com.topjohnwu.magisk.view.MagiskDialog
+
+class DownloadDialog(private val callback: (Uri) -> Unit) : DialogBuilder {
+
+    override fun build(dialog: MagiskDialog) {
+        val editText = EditText(dialog.context).apply {
+            inputType = InputType.TYPE_CLASS_TEXT or InputType.TYPE_TEXT_VARIATION_URI
+            hint = context.getString(R.string.download_dialog_msg)
+            requestFocus()
+        }
+
+        dialog.apply {
+            setTitle(R.string.download_dialog_title)
+            setView(editText)
+            setButton(MagiskDialog.ButtonType.POSITIVE) {
+                text = android.R.string.ok
+                onClick {
+                    val url = editText.text.toString().trim()
+                    isValidUrl(url)?.let {
+                        doNotDismiss = false
+                        callback(it)
+                    } ?: run {
+                        doNotDismiss = true
+                        editText.error = context.getString(R.string.download_dialog_title)
+                    }
+                }
+            }
+            setButton(MagiskDialog.ButtonType.NEGATIVE) {
+                text = android.R.string.cancel
+            }
+            setCancelable(true)
+        }
+    }
+
+    private fun isValidUrl(url: String): Uri? {
+        if (url.isEmpty()) {
+            return null
+        }
+        val uri = url.toUri()
+        if (!uri.scheme.equals("https", ignoreCase = true)) {
+            return null
+        }
+        if (uri.host.isNullOrEmpty()) {
+            return null
+        }
+        if (uri.path.isNullOrEmpty()) {
+            return null
+        }
+        return uri
+    }
+}
diff --git a/app/apk/src/main/java/com/topjohnwu/magisk/ui/flash/FlashFragment.kt b/app/apk/src/main/java/com/topjohnwu/magisk/ui/flash/FlashFragment.kt
index 7231a9b9f..fd694cfe4 100644
--- a/app/apk/src/main/java/com/topjohnwu/magisk/ui/flash/FlashFragment.kt
+++ b/app/apk/src/main/java/com/topjohnwu/magisk/ui/flash/FlashFragment.kt
@@ -127,6 +127,13 @@ class FlashFragment : BaseFragment<FragmentFlashMd2Binding>(), MenuProvider {
             additionalData = uri
         )
 
+        // Downloading is understood as downloading file then patch */
+
+        fun download(uri: Uri) = MainDirections.actionFlashFragment(
+            action = Const.Value.DOWNLOAD,
+            additionalData = uri
+        )
+
         /* Uninstalling is understood as removing magisk entirely */
 
         fun uninstall() = MainDirections.actionFlashFragment(
diff --git a/app/apk/src/main/java/com/topjohnwu/magisk/ui/flash/FlashViewModel.kt b/app/apk/src/main/java/com/topjohnwu/magisk/ui/flash/FlashViewModel.kt
index 56704d869..661f40dea 100644
--- a/app/apk/src/main/java/com/topjohnwu/magisk/ui/flash/FlashViewModel.kt
+++ b/app/apk/src/main/java/com/topjohnwu/magisk/ui/flash/FlashViewModel.kt
@@ -1,5 +1,6 @@
 package com.topjohnwu.magisk.ui.flash
 
+import android.os.Build
 import android.view.MenuItem
 import androidx.databinding.Bindable
 import androidx.databinding.ObservableArrayList
@@ -80,6 +81,13 @@ class FlashViewModel : BaseViewModel() {
                     showReboot = false
                     MagiskInstaller.Patch(uri, outItems, logItems).exec()
                 }
+                Const.Value.DOWNLOAD -> {
+                    if (uri == null || Build.VERSION.SDK_INT < 29) {
+                        return@launch
+                    }
+                    showReboot = false
+                    MagiskInstaller.Download(uri.toString(), outItems, logItems).exec()
+                }
                 else -> {
                     back()
                     return@launch
diff --git a/app/apk/src/main/java/com/topjohnwu/magisk/ui/install/InstallViewModel.kt b/app/apk/src/main/java/com/topjohnwu/magisk/ui/install/InstallViewModel.kt
index 6508ce4e1..b6a64dffd 100644
--- a/app/apk/src/main/java/com/topjohnwu/magisk/ui/install/InstallViewModel.kt
+++ b/app/apk/src/main/java/com/topjohnwu/magisk/ui/install/InstallViewModel.kt
@@ -21,6 +21,7 @@ import com.topjohnwu.magisk.core.base.ContentResultCallback
 import com.topjohnwu.magisk.core.ktx.toast
 import com.topjohnwu.magisk.core.repository.NetworkService
 import com.topjohnwu.magisk.databinding.set
+import com.topjohnwu.magisk.dialog.DownloadDialog
 import com.topjohnwu.magisk.dialog.SecondSlotWarningDialog
 import com.topjohnwu.magisk.events.GetContentEvent
 import com.topjohnwu.magisk.ui.flash.FlashFragment
@@ -54,6 +55,9 @@ class InstallViewModel(svc: NetworkService, markwon: Markwon) : BaseViewModel()
                 R.id.method_patch -> {
                     GetContentEvent("*/*", UriCallback()).publish()
                 }
+                R.id.method_download -> {
+                    DownloadDialog { url -> uri.value = url }.show()
+                }
                 R.id.method_inactive_slot -> {
                     SecondSlotWarningDialog().show()
                 }
@@ -92,6 +96,7 @@ class InstallViewModel(svc: NetworkService, markwon: Markwon) : BaseViewModel()
     fun install() {
         when (method) {
             R.id.method_patch -> FlashFragment.patch(data.value!!).navigate(true)
+            R.id.method_download -> FlashFragment.download(data.value!!).navigate(true)
             R.id.method_direct -> FlashFragment.flash(false).navigate(true)
             R.id.method_inactive_slot -> FlashFragment.flash(true).navigate(true)
             else -> error("Unknown value")
diff --git a/app/apk/src/main/res/layout/fragment_install_md2.xml b/app/apk/src/main/res/layout/fragment_install_md2.xml
index 7a7364379..5305a87a2 100644
--- a/app/apk/src/main/res/layout/fragment_install_md2.xml
+++ b/app/apk/src/main/res/layout/fragment_install_md2.xml
@@ -161,7 +161,7 @@
                         <Button
                             style="@style/WidgetFoundation.Button.Text"
                             gone="@{viewModel.step != 1}"
-                            isEnabled="@{viewModel.method == @id/method_patch ? viewModel.data != null : viewModel.method != -1}"
+                            isEnabled="@{(viewModel.method == @id/method_patch || viewModel.method == @id/method_download) ? viewModel.data != null : viewModel.method != -1}"
                             android:layout_width="wrap_content"
                             android:layout_height="wrap_content"
                             android:onClick="@{() -> viewModel.install()}"
@@ -190,6 +190,14 @@
                             android:layout_height="wrap_content"
                             android:text="@string/select_patch_file" />
 
+                        <RadioButton
+                            android:id="@+id/method_download"
+                            style="@style/WidgetFoundation.RadioButton"
+                            android:layout_width="match_parent"
+                            gone="@{android.os.Build.VERSION.SDK_INT &lt; 29}"
+                            android:layout_height="wrap_content"
+                            android:text="@string/download_patch_file" />
+
                         <RadioButton
                             android:id="@+id/method_direct"
                             style="@style/WidgetFoundation.RadioButton"
diff --git a/app/core/build.gradle.kts b/app/core/build.gradle.kts
index 4dd208a15..26f573e0b 100644
--- a/app/core/build.gradle.kts
+++ b/app/core/build.gradle.kts
@@ -1,8 +1,11 @@
+import com.google.protobuf.gradle.id
+
 plugins {
     alias(libs.plugins.android.library)
     kotlin("plugin.parcelize")
     alias(libs.plugins.moshix)
     alias(libs.plugins.ksp)
+    alias(libs.plugins.protobuf)
 }
 
 setupCoreLib()
@@ -11,6 +14,21 @@ ksp {
     arg("room.generateKotlin", "true")
 }
 
+protobuf {
+    protoc {
+        artifact = libs.protobuf.protoc.get().toString()
+    }
+    generateProtoTasks {
+        ofNonTest().forEach { task ->
+            task.builtins {
+                id("java") {
+                    option("lite")
+                }
+            }
+        }
+    }
+}
+
 android {
     namespace = "com.topjohnwu.magisk.core"
 
@@ -40,6 +58,8 @@ dependencies {
     api(libs.markwon.core)
     implementation(libs.bcpkix)
     implementation(libs.commons.compress)
+    implementation(libs.xz)
+    implementation(libs.protobuf.javalite)
 
     api(libs.libsu.core)
     api(libs.libsu.service)
diff --git a/app/core/proguard-rules.pro b/app/core/proguard-rules.pro
index 9fde52bc6..dbf637451 100644
--- a/app/core/proguard-rules.pro
+++ b/app/core/proguard-rules.pro
@@ -28,6 +28,9 @@
   public void d(**);
 }
 
+# Protobuf
+-shrinkunusedprotofields
+
 # With R8 full mode generic signatures are stripped for classes that are not
 # kept. Suspend functions are wrapped in continuations where the type argument
 # is used.
diff --git a/app/core/src/main/java/com/topjohnwu/magisk/core/Const.kt b/app/core/src/main/java/com/topjohnwu/magisk/core/Const.kt
index e6f432d29..db39684a8 100644
--- a/app/core/src/main/java/com/topjohnwu/magisk/core/Const.kt
+++ b/app/core/src/main/java/com/topjohnwu/magisk/core/Const.kt
@@ -56,6 +56,7 @@ object Const {
     object Value {
         const val FLASH_ZIP = "flash"
         const val PATCH_FILE = "patch"
+        const val DOWNLOAD = "download"
         const val FLASH_MAGISK = "magisk"
         const val FLASH_INACTIVE_SLOT = "slot"
         const val UNINSTALL = "uninstall"
diff --git a/app/core/src/main/java/com/topjohnwu/magisk/core/tasks/MagiskInstaller.kt b/app/core/src/main/java/com/topjohnwu/magisk/core/tasks/MagiskInstaller.kt
index 4468d3a9c..94e0034c7 100644
--- a/app/core/src/main/java/com/topjohnwu/magisk/core/tasks/MagiskInstaller.kt
+++ b/app/core/src/main/java/com/topjohnwu/magisk/core/tasks/MagiskInstaller.kt
@@ -1,11 +1,13 @@
 package com.topjohnwu.magisk.core.tasks
 
 import android.net.Uri
+import android.os.FileUtils
 import android.os.Process
 import android.system.ErrnoException
 import android.system.Os
 import android.system.OsConstants
 import android.system.OsConstants.O_WRONLY
+import androidx.annotation.RequiresApi
 import androidx.annotation.WorkerThread
 import androidx.core.os.postDelayed
 import com.topjohnwu.magisk.StubApk
@@ -21,6 +23,7 @@ import com.topjohnwu.magisk.core.ktx.writeTo
 import com.topjohnwu.magisk.core.utils.DummyList
 import com.topjohnwu.magisk.core.utils.MediaStoreUtils
 import com.topjohnwu.magisk.core.utils.MediaStoreUtils.inputStream
+import com.topjohnwu.magisk.core.utils.MediaStoreUtils.openFd
 import com.topjohnwu.magisk.core.utils.MediaStoreUtils.outputStream
 import com.topjohnwu.magisk.core.utils.RootUtils
 import com.topjohnwu.superuser.Shell
@@ -39,6 +42,8 @@ import org.apache.commons.compress.archivers.zip.ZipFile
 import org.apache.commons.compress.compressors.lz4.FramedLZ4CompressorInputStream
 import timber.log.Timber
 import java.io.File
+import java.io.FileInputStream
+import java.io.FileOutputStream
 import java.io.FilterInputStream
 import java.io.IOException
 import java.io.InputStream
@@ -530,6 +535,53 @@ abstract class MagiskInstallImpl protected constructor(
         return true
     }
 
+    @RequiresApi(29)
+    private fun processUrl(url: String): Boolean {
+        // Download image from url
+        try {
+            srcBoot = installDir.getChildFile("boot.img")
+            //todo
+        } catch (e: IOException) {
+            console.add("! Error: " + e.message)
+            Timber.e(e)
+            return false
+        }
+
+        // Patch file
+        if (!patchBoot()) {
+            return false
+        }
+
+        // Output file
+        val outFile = MediaStoreUtils.getFile("$destName.img")
+        try {
+            val newBoot = installDir.getChildFile("new-boot.img")
+            outFile.uri.openFd().use { out ->
+                FileInputStream(newBoot).use { input ->
+                    FileUtils.copy(input, FileOutputStream(out.fileDescriptor))
+                }
+            }
+            newBoot.delete()
+
+            console.add("")
+            console.add("****************************")
+            console.add(" Output file is written to ")
+            console.add(" $outFile ")
+            console.add("****************************")
+        } catch (e: IOException) {
+            console.add("! Failed to output to $outFile")
+            outFile.delete()
+            Timber.e(e)
+            return false
+        }
+
+        // Fix up binaries
+        srcBoot.delete()
+        "cp_readlink $installDir".sh()
+
+        return true
+    }
+
     private fun patchBoot(): Boolean {
         val newBoot = installDir.getChildFile("new-boot.img")
         if (!useRootDir) {
@@ -581,6 +633,9 @@ abstract class MagiskInstallImpl protected constructor(
 
     protected suspend fun patchFile(file: Uri) = extractFiles() && processFile(file)
 
+    @RequiresApi(29)
+    protected suspend fun patchFile(url: String) = extractFiles() && processUrl(url)
+
     protected suspend fun direct() = findImage() && extractFiles() && patchBoot() && flashBoot()
 
     protected suspend fun secondSlot() =
@@ -648,6 +703,15 @@ class MagiskInstaller {
         override suspend fun operations() = patchFile(uri)
     }
 
+    @RequiresApi(29)
+    class Download(
+        private val url: String,
+        console: MutableList<String>,
+        logs: MutableList<String>
+    ) : ConsoleInstaller(console, logs) {
+        override suspend fun operations() = patchFile(url)
+    }
+
     class SecondSlot(
         console: MutableList<String>,
         logs: MutableList<String>
diff --git a/app/core/src/main/java/com/topjohnwu/magisk/core/utils/MediaStoreUtils.kt b/app/core/src/main/java/com/topjohnwu/magisk/core/utils/MediaStoreUtils.kt
index 5a63547bc..1c25736c6 100644
--- a/app/core/src/main/java/com/topjohnwu/magisk/core/utils/MediaStoreUtils.kt
+++ b/app/core/src/main/java/com/topjohnwu/magisk/core/utils/MediaStoreUtils.kt
@@ -98,6 +98,8 @@ object MediaStoreUtils {
 
     fun Uri.outputStream() = cr.openOutputStream(this, "rwt") ?: throw FileNotFoundException()
 
+    fun Uri.openFd() = cr.openFileDescriptor(this, "rwt") ?: throw FileNotFoundException()
+
     val Uri.displayName: String get() {
         if (scheme == "file") {
             // Simple uri wrapper over file, directly get file name
diff --git a/app/core/src/main/proto/update_metadata.proto b/app/core/src/main/proto/update_metadata.proto
new file mode 100644
index 000000000..6d16da40e
--- /dev/null
+++ b/app/core/src/main/proto/update_metadata.proto
@@ -0,0 +1,445 @@
+//
+// Copyright (C) 2010 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// Update file format: An update file contains all the operations needed
+// to update a system to a specific version. It can be a full payload which
+// can update from any version, or a delta payload which can only update
+// from a specific version.
+// The update format is represented by this struct pseudocode:
+// struct delta_update_file {
+//   char magic[4] = "CrAU";
+//   uint64 file_format_version;  // payload major version
+//   uint64 manifest_size;  // Size of protobuf DeltaArchiveManifest
+//
+//   // Only present if format_version >= 2:
+//   uint32 metadata_signature_size;
+//
+//   // The DeltaArchiveManifest protobuf serialized, not compressed.
+//   char manifest[manifest_size];
+//
+//   // The signature of the metadata (from the beginning of the payload up to
+//   // this location, not including the signature itself). This is a serialized
+//   // Signatures message.
+//   char metadata_signature_message[metadata_signature_size];
+//
+//   // Data blobs for files, no specific format. The specific offset
+//   // and length of each data blob is recorded in the DeltaArchiveManifest.
+//   struct {
+//     char data[];
+//   } blobs[];
+//
+//   // The signature of the entire payload, everything up to this location,
+//   // except that metadata_signature_message is skipped to simplify signing
+//   // process. These two are not signed:
+//   uint64 payload_signatures_message_size;
+//   // This is a serialized Signatures message.
+//   char payload_signatures_message[payload_signatures_message_size];
+//
+// };
+
+// The DeltaArchiveManifest protobuf is an ordered list of InstallOperation
+// objects. These objects are stored in a linear array in the
+// DeltaArchiveManifest. Each operation is applied in order by the client.
+
+// The DeltaArchiveManifest also contains the initial and final
+// checksums for the device.
+
+// The client will perform each InstallOperation in order, beginning even
+// before the entire delta file is downloaded (but after at least the
+// protobuf is downloaded). The types of operations are explained:
+// - REPLACE: Replace the dst_extents on the drive with the attached data,
+//   zero padding out to block size.
+// - REPLACE_BZ: bzip2-uncompress the attached data and write it into
+//   dst_extents on the drive, zero padding to block size.
+// - MOVE: Copy the data in src_extents to dst_extents. Extents may overlap,
+//   so it may be desirable to read all src_extents data into memory before
+//   writing it out. (deprecated)
+// - SOURCE_COPY: Copy the data in src_extents in the old partition to
+//   dst_extents in the new partition. There's no overlapping of data because
+//   the extents are in different partitions.
+// - BSDIFF: Read src_length bytes from src_extents into memory, perform
+//   bspatch with attached data, write new data to dst_extents, zero padding
+//   to block size. (deprecated)
+// - SOURCE_BSDIFF: Read the data in src_extents in the old partition, perform
+//   bspatch with the attached data and write the new data to dst_extents in the
+//   new partition.
+// - ZERO: Write zeros to the destination dst_extents.
+// - DISCARD: Discard the destination dst_extents blocks on the physical medium.
+//   the data read from those blocks is undefined.
+// - REPLACE_XZ: Replace the dst_extents with the contents of the attached
+//   xz file after decompression. The xz file should only use crc32 or no crc at
+//   all to be compatible with xz-embedded.
+// - PUFFDIFF: Read the data in src_extents in the old partition, perform
+//   puffpatch with the attached data and write the new data to dst_extents in
+//   the new partition.
+//
+// The operations allowed in the payload (supported by the client) depend on the
+// major and minor version. See InstallOperation.Type below for details.
+
+syntax = "proto2";
+
+package chromeos_update_engine;
+
+// Data is packed into blocks on disk, always starting from the beginning
+// of the block. If a file's data is too large for one block, it overflows
+// into another block, which may or may not be the following block on the
+// physical partition. An ordered list of extents is another
+// representation of an ordered list of blocks. For example, a file stored
+// in blocks 9, 10, 11, 2, 18, 12 (in that order) would be stored in
+// extents { {9, 3}, {2, 1}, {18, 1}, {12, 1} } (in that order).
+// In general, files are stored sequentially on disk, so it's more efficient
+// to use extents to encode the block lists (this is effectively
+// run-length encoding).
+// A sentinel value (kuint64max) as the start block denotes a sparse-hole
+// in a file whose block-length is specified by num_blocks.
+
+message Extent {
+  optional uint64 start_block = 1;
+  optional uint64 num_blocks = 2;
+}
+
+// Signatures: Updates may be signed by the OS vendor. The client verifies
+// an update's signature by hashing the entire download. The section of the
+// download that contains the signature is at the end of the file, so when
+// signing a file, only the part up to the signature part is signed.
+// Then, the client looks inside the download's Signatures message for a
+// Signature message that it knows how to handle. Generally, a client will
+// only know how to handle one type of signature, but an update may contain
+// many signatures to support many different types of client. Then client
+// selects a Signature message and uses that, along with a known public key,
+// to verify the download. The public key is expected to be part of the
+// client.
+
+message Signatures {
+  message Signature {
+    optional uint32 version = 1 [deprecated = true];
+    optional bytes data = 2;
+
+    // The DER encoded signature size of EC keys is nondeterministic for
+    // different input of sha256 hash. However, we need the size of the
+    // serialized signatures protobuf string to be fixed before signing;
+    // because this size is part of the content to be signed. Therefore, we
+    // always pad the signature data to the maximum possible signature size of
+    // a given key. And the payload verifier will truncate the signature to
+    // its correct size based on the value of |unpadded_signature_size|.
+    optional fixed32 unpadded_signature_size = 3;
+  }
+  repeated Signature signatures = 1;
+}
+
+message PartitionInfo {
+  optional uint64 size = 1;
+  optional bytes hash = 2;
+}
+
+message InstallOperation {
+  enum Type {
+    REPLACE = 0;     // Replace destination extents w/ attached data.
+    REPLACE_BZ = 1;  // Replace destination extents w/ attached bzipped data.
+    MOVE = 2 [deprecated = true];    // Move source extents to target extents.
+    BSDIFF = 3 [deprecated = true];  // The data is a bsdiff binary diff.
+
+    // On minor version 2 or newer, these operations are supported:
+    SOURCE_COPY = 4;    // Copy from source to target partition
+    SOURCE_BSDIFF = 5;  // Like BSDIFF, but read from source partition
+
+    // On minor version 3 or newer and on major version 2 or newer, these
+    // operations are supported:
+    REPLACE_XZ = 8;  // Replace destination extents w/ attached xz data.
+
+    // On minor version 4 or newer, these operations are supported:
+    ZERO = 6;     // Write zeros in the destination.
+    DISCARD = 7;  // Discard the destination blocks, reading as undefined.
+    BROTLI_BSDIFF = 10;  // Like SOURCE_BSDIFF, but compressed with brotli.
+
+    // On minor version 5 or newer, these operations are supported:
+    PUFFDIFF = 9;  // The data is in puffdiff format.
+
+    // On minor version 8 or newer, these operations are supported:
+    ZUCCHINI = 11;
+
+    // On minor version 9 or newer, these operations are supported:
+    LZ4DIFF_BSDIFF = 12;
+    LZ4DIFF_PUFFDIFF = 13;
+  }
+  required Type type = 1;
+
+  // Only minor version 6 or newer support 64 bits |data_offset| and
+  // |data_length|, older client will read them as uint32.
+  // The offset into the delta file (after the protobuf)
+  // where the data (if any) is stored
+  optional uint64 data_offset = 2;
+  // The length of the data in the delta file
+  optional uint64 data_length = 3;
+
+  // Ordered list of extents that are read from (if any) and written to.
+  repeated Extent src_extents = 4;
+  // Byte length of src, equal to the number of blocks in src_extents *
+  // block_size. It is used for BSDIFF and SOURCE_BSDIFF, because we need to
+  // pass that external program the number of bytes to read from the blocks we
+  // pass it.  This is not used in any other operation.
+  optional uint64 src_length = 5;
+
+  repeated Extent dst_extents = 6;
+  // Byte length of dst, equal to the number of blocks in dst_extents *
+  // block_size. Used for BSDIFF and SOURCE_BSDIFF, but not in any other
+  // operation.
+  optional uint64 dst_length = 7;
+
+  // Optional SHA 256 hash of the blob associated with this operation.
+  // This is used as a primary validation for http-based downloads and
+  // as a defense-in-depth validation for https-based downloads. If
+  // the operation doesn't refer to any blob, this field will have
+  // zero bytes.
+  optional bytes data_sha256_hash = 8;
+
+  // Indicates the SHA 256 hash of the source data referenced in src_extents at
+  // the time of applying the operation. If present, the update_engine daemon
+  // MUST read and verify the source data before applying the operation.
+  optional bytes src_sha256_hash = 9;
+}
+
+// Hints to VAB snapshot to skip writing some blocks if these blocks are
+// identical to the ones on the source image. The src & dst extents for each
+// CowMergeOperation should be contiguous, and they're a subset of an OTA
+// InstallOperation.
+// During merge time, we need to follow the pre-computed sequence to avoid
+// read after write, similar to the inplace update schema.
+message CowMergeOperation {
+  enum Type {
+    COW_COPY = 0;     // identical blocks
+    COW_XOR = 1;      // used when src/dst blocks are highly similar
+    COW_REPLACE = 2;  // Raw replace operation
+  }
+  optional Type type = 1;
+
+  optional Extent src_extent = 2;
+  optional Extent dst_extent = 3;
+  // For COW_XOR, source location might be unaligned, so this field is in range
+  // [0, block_size), representing how much should the src_extent shift toward
+  // larger block number. If this field is non-zero, then src_extent will
+  // include 1 extra block in the end, as the merge op actually references the
+  // first |src_offset| bytes of that extra block. For example, if |dst_extent|
+  // is [10, 15], |src_offset| is 500, then src_extent might look like [25, 31].
+  // Note that |src_extent| contains 1 extra block than the |dst_extent|.
+  optional uint32 src_offset = 4;
+}
+
+// Describes the update to apply to a single partition.
+message PartitionUpdate {
+  // A platform-specific name to identify the partition set being updated. For
+  // example, in Chrome OS this could be "ROOT" or "KERNEL".
+  required string partition_name = 1;
+
+  // Whether this partition carries a filesystem with post-install program that
+  // must be run to finalize the update process. See also |postinstall_path| and
+  // |filesystem_type|.
+  optional bool run_postinstall = 2;
+
+  // The path of the executable program to run during the post-install step,
+  // relative to the root of this filesystem. If not set, the default "postinst"
+  // will be used. This setting is only used when |run_postinstall| is set and
+  // true.
+  optional string postinstall_path = 3;
+
+  // The filesystem type as passed to the mount(2) syscall when mounting the new
+  // filesystem to run the post-install program. If not set, a fixed list of
+  // filesystems will be attempted. This setting is only used if
+  // |run_postinstall| is set and true.
+  optional string filesystem_type = 4;
+
+  // If present, a list of signatures of the new_partition_info.hash signed with
+  // different keys. If the update_engine daemon requires vendor-signed images
+  // and has its public key installed, one of the signatures should be valid
+  // for /postinstall to run.
+  repeated Signatures.Signature new_partition_signature = 5;
+
+  optional PartitionInfo old_partition_info = 6;
+  optional PartitionInfo new_partition_info = 7;
+
+  // The list of operations to be performed to apply this PartitionUpdate. The
+  // associated operation blobs (in operations[i].data_offset, data_length)
+  // should be stored contiguously and in the same order.
+  repeated InstallOperation operations = 8;
+
+  // Whether a failure in the postinstall step for this partition should be
+  // ignored.
+  optional bool postinstall_optional = 9;
+
+  // On minor version 6 or newer, these fields are supported:
+
+  // The extent for data covered by verity hash tree.
+  optional Extent hash_tree_data_extent = 10;
+
+  // The extent to store verity hash tree.
+  optional Extent hash_tree_extent = 11;
+
+  // The hash algorithm used in verity hash tree.
+  optional string hash_tree_algorithm = 12;
+
+  // The salt used for verity hash tree.
+  optional bytes hash_tree_salt = 13;
+
+  // The extent for data covered by FEC.
+  optional Extent fec_data_extent = 14;
+
+  // The extent to store FEC.
+  optional Extent fec_extent = 15;
+
+  // The number of FEC roots.
+  optional uint32 fec_roots = 16 [default = 2];
+
+  // Per-partition version used for downgrade detection, added
+  // as an effort to support partial updates. For most partitions,
+  // this is the build timestamp.
+  optional string version = 17;
+
+  // A sorted list of CowMergeOperation. When writing cow, we can choose to
+  // skip writing the raw bytes for these extents. During snapshot merge, the
+  // bytes will read from the source partitions instead.
+  repeated CowMergeOperation merge_operations = 18;
+
+  // Estimated size for COW image. This is used by libsnapshot
+  // as a hint. If set to 0, libsnapshot should use alternative
+  // methods for estimating size.
+  optional uint64 estimate_cow_size = 19;
+
+  // Information about the cow used by Cow Writer to specify
+  // number of cow operations to be written
+  optional uint64 estimate_op_count_max = 20;
+}
+
+message DynamicPartitionGroup {
+  // Name of the group.
+  required string name = 1;
+
+  // Maximum size of the group. The sum of sizes of all partitions in the group
+  // must not exceed the maximum size of the group.
+  optional uint64 size = 2;
+
+  // A list of partitions that belong to the group.
+  repeated string partition_names = 3;
+}
+
+message VABCFeatureSet {
+  optional bool threaded = 1;
+  optional bool batch_writes = 2;
+}
+
+// Metadata related to all dynamic partitions.
+message DynamicPartitionMetadata {
+  // All updatable groups present in |partitions| of this DeltaArchiveManifest.
+  // - If an updatable group is on the device but not in the manifest, it is
+  //   not updated. Hence, the group will not be resized, and partitions cannot
+  //   be added to or removed from the group.
+  // - If an updatable group is in the manifest but not on the device, the group
+  //   is added to the device.
+  repeated DynamicPartitionGroup groups = 1;
+
+  // Whether dynamic partitions have snapshots during the update. If this is
+  // set to true, the update_engine daemon creates snapshots for all dynamic
+  // partitions if possible. If this is unset, the update_engine daemon MUST
+  // NOT create snapshots for dynamic partitions.
+  optional bool snapshot_enabled = 2;
+
+  // If this is set to false, update_engine should not use VABC regardless. If
+  // this is set to true, update_engine may choose to use VABC if device
+  // supports it, but not guaranteed.
+  // VABC stands for Virtual AB Compression
+  optional bool vabc_enabled = 3;
+
+  // The compression algorithm used by VABC. Available ones are "gz", "brotli".
+  // See system/core/fs_mgr/libsnapshot/cow_writer.cpp for available options,
+  // as this parameter is ultimated forwarded to libsnapshot's CowWriter
+  optional string vabc_compression_param = 4;
+
+  // COW version used by VABC. The represents the major version in the COW
+  // header
+  optional uint32 cow_version = 5;
+
+  // A collection of knobs to tune Virtual AB Compression
+  optional VABCFeatureSet vabc_feature_set = 6;
+
+  // Max bytes to be compressed at once during ota. Options: 4k, 8k, 16k, 32k,
+  // 64k, 128k
+  optional uint64 compression_factor = 7;
+}
+
+// Definition has been duplicated from
+// $ANDROID_BUILD_TOP/build/tools/releasetools/ota_metadata.proto. Keep in sync.
+message ApexInfo {
+  optional string package_name = 1;
+  optional int64 version = 2;
+  optional bool is_compressed = 3;
+  optional int64 decompressed_size = 4;
+}
+
+// Definition has been duplicated from
+// $ANDROID_BUILD_TOP/build/tools/releasetools/ota_metadata.proto. Keep in sync.
+message ApexMetadata {
+  repeated ApexInfo apex_info = 1;
+}
+
+message DeltaArchiveManifest {
+  // Only present in major version = 1. List of install operations for the
+  // kernel and rootfs partitions. For major version = 2 see the |partitions|
+  // field.
+  reserved 1, 2;
+
+  // (At time of writing) usually 4096
+  optional uint32 block_size = 3 [default = 4096];
+
+  // If signatures are present, the offset into the blobs, generally
+  // tacked onto the end of the file, and the length. We use an offset
+  // rather than a bool to allow for more flexibility in future file formats.
+  // If either is absent, it means signatures aren't supported in this
+  // file.
+  optional uint64 signatures_offset = 4;
+  optional uint64 signatures_size = 5;
+
+  // Fields deprecated in major version 2.
+  reserved 6,7,8,9,10,11;
+
+  // The minor version, also referred as "delta version", of the payload.
+  // Minor version 0 is full payload, everything else is delta payload.
+  optional uint32 minor_version = 12 [default = 0];
+
+  // Only present in major version >= 2. List of partitions that will be
+  // updated, in the order they will be updated. This field replaces the
+  // |install_operations|, |kernel_install_operations| and the
+  // |{old,new}_{kernel,rootfs}_info| fields used in major version = 1. This
+  // array can have more than two partitions if needed, and they are identified
+  // by the partition name.
+  repeated PartitionUpdate partitions = 13;
+
+  // The maximum timestamp of the OS allowed to apply this payload.
+  // Can be used to prevent downgrading the OS.
+  optional int64 max_timestamp = 14;
+
+  // Metadata related to all dynamic partitions.
+  optional DynamicPartitionMetadata dynamic_partition_metadata = 15;
+
+  // If the payload only updates a subset of partitions on the device.
+  optional bool partial_update = 16;
+
+  // Information on compressed APEX to figure out how much space is required for
+  // their decompression
+  repeated ApexInfo apex_info = 17;
+
+  // Security patch level of the device, usually in the format of
+  // yyyy-mm-dd
+  optional string security_patch_level = 18;
+}
diff --git a/app/core/src/main/res/values/strings.xml b/app/core/src/main/res/values/strings.xml
index dd2e639f4..925d01c01 100644
--- a/app/core/src/main/res/values/strings.xml
+++ b/app/core/src/main/res/values/strings.xml
@@ -56,6 +56,9 @@
     <string name="setup_title">Additional setup</string>
     <string name="select_patch_file">Select and patch a file</string>
     <string name="patch_file_msg">Select a raw image (*.img) or an ODIN tarfile (*.tar) or a payload.bin (*.bin)</string>
+    <string name="download_patch_file">Download and patch a file</string>
+    <string name="download_dialog_title">Enter image URL</string>
+    <string name="download_dialog_msg">Full OTA image or factory image</string>
     <string name="reboot_delay_toast">Rebooting in 5 seconds…</string>
     <string name="flash_screen_title">Installation</string>
 
diff --git a/app/gradle.properties b/app/gradle.properties
index 29949ae98..ba50543f3 100644
--- a/app/gradle.properties
+++ b/app/gradle.properties
@@ -25,6 +25,7 @@ kapt.use.k2=true
 
 # Android
 android.injected.testOnly=false
+android.newDsl=false
 
 # Magisk
 magisk.stubVersion=40
diff --git a/app/gradle/libs.versions.toml b/app/gradle/libs.versions.toml
index 0dd5881af..6f69b4321 100644
--- a/app/gradle/libs.versions.toml
+++ b/app/gradle/libs.versions.toml
@@ -14,6 +14,7 @@ compose-ui = "1.10.6"
 compose-m3 = "1.4.0"
 navigation3 = "1.1.0-rc01"
 navigationevent = "1.0.2"
+protobuf = "4.31.1"
 
 [libraries]
 bcpkix = { module = "org.bouncycastle:bcpkix-jdk18on", version = "1.83" }
@@ -26,6 +27,9 @@ okhttp = { module = "com.squareup.okhttp3:okhttp", version.ref = "okhttp" }
 okhttp-dnsoverhttps = { module = "com.squareup.okhttp3:okhttp-dnsoverhttps", version.ref = "okhttp" }
 okhttp-logging = { module = "com.squareup.okhttp3:logging-interceptor", version.ref = "okhttp" }
 timber = { module = "com.jakewharton.timber:timber", version = "5.0.1" }
+protobuf-javalite = { module = "com.google.protobuf:protobuf-javalite", version.ref = "protobuf" }
+protobuf-protoc = { module = "com.google.protobuf:protoc", version.ref = "protobuf" }
+xz = { module = "org.tukaani:xz", version = "1.10" }
 
 # AndroidX
 activity = { module = "androidx.activity:activity", version = "1.13.0" }
@@ -90,3 +94,4 @@ compose-compiler = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "
 lsparanoid = { id = "org.lsposed.lsparanoid", version = "0.6.0" }
 moshix = { id = "dev.zacsweers.moshix", version = "0.35.0" }
 navigation-safeargs = { id = "androidx.navigation.safeargs.kotlin", version.ref = "navigation" }
+protobuf = { id = "com.google.protobuf", version = "0.9.6" }