14 files changed, 2389 insertions, 0 deletions

diff --git a/install/Android.bp b/install/Android.bp
new file mode 100644
index 000000000..aa47990ae
--- /dev/null
+++ b/install/Android.bp
@@ -0,0 +1,78 @@
+// Copyright (C) 2019 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.
+
+cc_defaults {
+    name: "libinstall_defaults",
+
+    defaults: [
+        "recovery_defaults",
+    ],
+
+    shared_libs: [
+        "libbase",
+        "libbootloader_message",
+        "libcrypto",
+        "libext4_utils",
+        "libfs_mgr",
+        "libfusesideload",
+        "libhidl-gen-utils",
+        "libhidlbase",
+        "libhidltransport",
+        "liblog",
+        "libselinux",
+        "libtinyxml2",
+        "libutils",
+        "libz",
+        "libziparchive",
+    ],
+
+    static_libs: [
+        "libotautil",
+
+        // external dependencies
+        "libvintf_recovery",
+        "libvintf",
+        "libfstab",
+    ],
+}
+
+cc_library {
+    name: "libinstall",
+    recovery_available: true,
+
+    defaults: [
+        "libinstall_defaults",
+    ],
+
+    srcs: [
+        "adb_install.cpp",
+        "asn1_decoder.cpp",
+        "fuse_sdcard_install.cpp",
+        "install.cpp",
+        "package.cpp",
+        "verifier.cpp",
+    ],
+
+    shared_libs: [
+        "librecovery_ui",
+    ],
+
+    export_include_dirs: [
+        "include",
+    ],
+
+    export_shared_lib_headers: [
+        "librecovery_ui",
+    ],
+}
diff --git a/install/adb_install.cpp b/install/adb_install.cpp
new file mode 100644
index 000000000..5296ff608
--- /dev/null
+++ b/install/adb_install.cpp
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+#include "install/adb_install.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+
+#include "fuse_sideload.h"
+#include "install/install.h"
+#include "recovery_ui/ui.h"
+
+static bool SetUsbConfig(const std::string& state) {
+  android::base::SetProperty("sys.usb.config", state);
+  return android::base::WaitForProperty("sys.usb.state", state);
+}
+
+int apply_from_adb(bool* wipe_cache, RecoveryUI* ui) {
+  // Save the usb state to restore after the sideload operation.
+  std::string usb_state = android::base::GetProperty("sys.usb.state", "none");
+  // Clean up state and stop adbd.
+  if (usb_state != "none" && !SetUsbConfig("none")) {
+    LOG(ERROR) << "Failed to clear USB config";
+    return INSTALL_ERROR;
+  }
+
+  ui->Print(
+      "\n\nNow send the package you want to apply\n"
+      "to the device with \"adb sideload <filename>\"...\n");
+
+  pid_t child;
+  if ((child = fork()) == 0) {
+    execl("/system/bin/recovery", "recovery", "--adbd", nullptr);
+    _exit(EXIT_FAILURE);
+  }
+
+  if (!SetUsbConfig("sideload")) {
+    LOG(ERROR) << "Failed to set usb config to sideload";
+    return INSTALL_ERROR;
+  }
+
+  // How long (in seconds) we wait for the host to start sending us a package, before timing out.
+  static constexpr int ADB_INSTALL_TIMEOUT = 300;
+
+  // FUSE_SIDELOAD_HOST_PATHNAME will start to exist once the host connects and starts serving a
+  // package. Poll for its appearance. (Note that inotify doesn't work with FUSE.)
+  int result = INSTALL_ERROR;
+  int status;
+  bool waited = false;
+  for (int i = 0; i < ADB_INSTALL_TIMEOUT; ++i) {
+    if (waitpid(child, &status, WNOHANG) != 0) {
+      result = INSTALL_ERROR;
+      waited = true;
+      break;
+    }
+
+    struct stat st;
+    if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &st) != 0) {
+      if (errno == ENOENT && i < ADB_INSTALL_TIMEOUT - 1) {
+        sleep(1);
+        continue;
+      } else {
+        ui->Print("\nTimed out waiting for package.\n\n");
+        result = INSTALL_ERROR;
+        kill(child, SIGKILL);
+        break;
+      }
+    }
+    result = install_package(FUSE_SIDELOAD_HOST_PATHNAME, wipe_cache, false, 0, ui);
+    break;
+  }
+
+  if (!waited) {
+    // Calling stat() on this magic filename signals the minadbd subprocess to shut down.
+    struct stat st;
+    stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &st);
+
+    // TODO: there should be a way to cancel waiting for a package (by pushing some button combo on
+    // the device). For now you just have to 'adb sideload' a file that's not a valid package, like
+    // "/dev/null".
+    waitpid(child, &status, 0);
+  }
+
+  if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+    if (WEXITSTATUS(status) == 3) {
+      ui->Print("\nYou need adb 1.0.32 or newer to sideload\nto this device.\n\n");
+    } else if (!WIFSIGNALED(status)) {
+      ui->Print("\n(adbd status %d)\n", WEXITSTATUS(status));
+    }
+  }
+
+  // Clean up before switching to the older state, for example setting the state
+  // to none sets sys/class/android_usb/android0/enable to 0.
+  if (!SetUsbConfig("none")) {
+    LOG(ERROR) << "Failed to clear USB config";
+  }
+
+  if (usb_state != "none") {
+    if (!SetUsbConfig(usb_state)) {
+      LOG(ERROR) << "Failed to set USB config to " << usb_state;
+    }
+  }
+
+  return result;
+}
diff --git a/install/asn1_decoder.cpp b/install/asn1_decoder.cpp
new file mode 100644
index 000000000..2d81a6e13
--- /dev/null
+++ b/install/asn1_decoder.cpp
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#include "private/asn1_decoder.h"
+
+int asn1_context::peek_byte() const {
+  if (length_ == 0) {
+    return -1;
+  }
+  return *p_;
+}
+
+int asn1_context::get_byte() {
+  if (length_ == 0) {
+    return -1;
+  }
+
+  int byte = *p_;
+  p_++;
+  length_--;
+  return byte;
+}
+
+bool asn1_context::skip_bytes(size_t num_skip) {
+  if (length_ < num_skip) {
+    return false;
+  }
+  p_ += num_skip;
+  length_ -= num_skip;
+  return true;
+}
+
+bool asn1_context::decode_length(size_t* out_len) {
+  int num_octets = get_byte();
+  if (num_octets == -1) {
+    return false;
+  }
+  if ((num_octets & 0x80) == 0x00) {
+    *out_len = num_octets;
+    return true;
+  }
+  num_octets &= kMaskTag;
+  if (static_cast<size_t>(num_octets) >= sizeof(size_t)) {
+    return false;
+  }
+  size_t length = 0;
+  for (int i = 0; i < num_octets; ++i) {
+    int byte = get_byte();
+    if (byte == -1) {
+      return false;
+    }
+    length <<= 8;
+    length += byte;
+  }
+  *out_len = length;
+  return true;
+}
+
+/**
+ * Returns the constructed type and advances the pointer. E.g. A0 -> 0
+ */
+asn1_context* asn1_context::asn1_constructed_get() {
+  int type = get_byte();
+  if (type == -1 || (type & kMaskConstructed) != kTagConstructed) {
+    return nullptr;
+  }
+  size_t length;
+  if (!decode_length(&length) || length > length_) {
+    return nullptr;
+  }
+  asn1_context* app_ctx = new asn1_context(p_, length);
+  app_ctx->app_type_ = type & kMaskAppType;
+  return app_ctx;
+}
+
+bool asn1_context::asn1_constructed_skip_all() {
+  int byte = peek_byte();
+  while (byte != -1 && (byte & kMaskConstructed) == kTagConstructed) {
+    skip_bytes(1);
+    size_t length;
+    if (!decode_length(&length) || !skip_bytes(length)) {
+      return false;
+    }
+    byte = peek_byte();
+  }
+  return byte != -1;
+}
+
+int asn1_context::asn1_constructed_type() const {
+  return app_type_;
+}
+
+asn1_context* asn1_context::asn1_sequence_get() {
+  if ((get_byte() & kMaskTag) != kTagSequence) {
+    return nullptr;
+  }
+  size_t length;
+  if (!decode_length(&length) || length > length_) {
+    return nullptr;
+  }
+  return new asn1_context(p_, length);
+}
+
+asn1_context* asn1_context::asn1_set_get() {
+  if ((get_byte() & kMaskTag) != kTagSet) {
+    return nullptr;
+  }
+  size_t length;
+  if (!decode_length(&length) || length > length_) {
+    return nullptr;
+  }
+  return new asn1_context(p_, length);
+}
+
+bool asn1_context::asn1_sequence_next() {
+  size_t length;
+  if (get_byte() == -1 || !decode_length(&length) || !skip_bytes(length)) {
+    return false;
+  }
+  return true;
+}
+
+bool asn1_context::asn1_oid_get(const uint8_t** oid, size_t* length) {
+  if (get_byte() != kTagOid) {
+    return false;
+  }
+  if (!decode_length(length) || *length == 0 || *length > length_) {
+    return false;
+  }
+  *oid = p_;
+  return true;
+}
+
+bool asn1_context::asn1_octet_string_get(const uint8_t** octet_string, size_t* length) {
+  if (get_byte() != kTagOctetString) {
+    return false;
+  }
+  if (!decode_length(length) || *length == 0 || *length > length_) {
+    return false;
+  }
+  *octet_string = p_;
+  return true;
+}
diff --git a/install/fuse_sdcard_install.cpp b/install/fuse_sdcard_install.cpp
new file mode 100644
index 000000000..dde289f80
--- /dev/null
+++ b/install/fuse_sdcard_install.cpp
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include "install/fuse_sdcard_install.h"
+
+#include <dirent.h>
+#include <signal.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+
+#include "bootloader_message/bootloader_message.h"
+#include "fuse_provider.h"
+#include "fuse_sideload.h"
+#include "install/install.h"
+#include "otautil/roots.h"
+
+static constexpr const char* SDCARD_ROOT = "/sdcard";
+// How long (in seconds) we wait for the fuse-provided package file to
+// appear, before timing out.
+static constexpr int SDCARD_INSTALL_TIMEOUT = 10;
+
+// Set the BCB to reboot back into recovery (it won't resume the install from
+// sdcard though).
+static void SetSdcardUpdateBootloaderMessage() {
+  std::vector<std::string> options;
+  std::string err;
+  if (!update_bootloader_message(options, &err)) {
+    LOG(ERROR) << "Failed to set BCB message: " << err;
+  }
+}
+
+// Returns the selected filename, or an empty string.
+static std::string BrowseDirectory(const std::string& path, Device* device, RecoveryUI* ui) {
+  ensure_path_mounted(path);
+
+  std::unique_ptr<DIR, decltype(&closedir)> d(opendir(path.c_str()), closedir);
+  if (!d) {
+    PLOG(ERROR) << "error opening " << path;
+    return "";
+  }
+
+  std::vector<std::string> dirs;
+  std::vector<std::string> entries{ "../" };  // "../" is always the first entry.
+
+  dirent* de;
+  while ((de = readdir(d.get())) != nullptr) {
+    std::string name(de->d_name);
+
+    if (de->d_type == DT_DIR) {
+      // Skip "." and ".." entries.
+      if (name == "." || name == "..") continue;
+      dirs.push_back(name + "/");
+    } else if (de->d_type == DT_REG && android::base::EndsWithIgnoreCase(name, ".zip")) {
+      entries.push_back(name);
+    }
+  }
+
+  std::sort(dirs.begin(), dirs.end());
+  std::sort(entries.begin(), entries.end());
+
+  // Append dirs to the entries list.
+  entries.insert(entries.end(), dirs.begin(), dirs.end());
+
+  std::vector<std::string> headers{ "Choose a package to install:", path };
+
+  size_t chosen_item = 0;
+  while (true) {
+    chosen_item = ui->ShowMenu(
+        headers, entries, chosen_item, true,
+        std::bind(&Device::HandleMenuKey, device, std::placeholders::_1, std::placeholders::_2));
+
+    // Return if WaitKey() was interrupted.
+    if (chosen_item == static_cast<size_t>(RecoveryUI::KeyError::INTERRUPTED)) {
+      return "";
+    }
+
+    const std::string& item = entries[chosen_item];
+    if (chosen_item == 0) {
+      // Go up but continue browsing (if the caller is BrowseDirectory).
+      return "";
+    }
+
+    std::string new_path = path + "/" + item;
+    if (new_path.back() == '/') {
+      // Recurse down into a subdirectory.
+      new_path.pop_back();
+      std::string result = BrowseDirectory(new_path, device, ui);
+      if (!result.empty()) return result;
+    } else {
+      // Selected a zip file: return the path to the caller.
+      return new_path;
+    }
+  }
+
+  // Unreachable.
+}
+
+static bool StartSdcardFuse(const std::string& path) {
+  auto file_data_reader = std::make_unique<FuseFileDataProvider>(path, 65536);
+
+  if (!file_data_reader->Valid()) {
+    return false;
+  }
+
+  // The installation process expects to find the sdcard unmounted. Unmount it with MNT_DETACH so
+  // that our open file continues to work but new references see it as unmounted.
+  umount2("/sdcard", MNT_DETACH);
+
+  return run_fuse_sideload(std::move(file_data_reader)) == 0;
+}
+
+int ApplyFromSdcard(Device* device, bool* wipe_cache, RecoveryUI* ui) {
+  if (ensure_path_mounted(SDCARD_ROOT) != 0) {
+    LOG(ERROR) << "\n-- Couldn't mount " << SDCARD_ROOT << ".\n";
+    return INSTALL_ERROR;
+  }
+
+  std::string path = BrowseDirectory(SDCARD_ROOT, device, ui);
+  if (path.empty()) {
+    LOG(ERROR) << "\n-- No package file selected.\n";
+    ensure_path_unmounted(SDCARD_ROOT);
+    return INSTALL_ERROR;
+  }
+
+  ui->Print("\n-- Install %s ...\n", path.c_str());
+  SetSdcardUpdateBootloaderMessage();
+
+  // We used to use fuse in a thread as opposed to a process. Since accessing
+  // through fuse involves going from kernel to userspace to kernel, it leads
+  // to deadlock when a page fault occurs. (Bug: 26313124)
+  pid_t child;
+  if ((child = fork()) == 0) {
+    bool status = StartSdcardFuse(path);
+
+    _exit(status ? EXIT_SUCCESS : EXIT_FAILURE);
+  }
+
+  // FUSE_SIDELOAD_HOST_PATHNAME will start to exist once the fuse in child
+  // process is ready.
+  int result = INSTALL_ERROR;
+  int status;
+  bool waited = false;
+  for (int i = 0; i < SDCARD_INSTALL_TIMEOUT; ++i) {
+    if (waitpid(child, &status, WNOHANG) == -1) {
+      result = INSTALL_ERROR;
+      waited = true;
+      break;
+    }
+
+    struct stat sb;
+    if (stat(FUSE_SIDELOAD_HOST_PATHNAME, &sb) == -1) {
+      if (errno == ENOENT && i < SDCARD_INSTALL_TIMEOUT - 1) {
+        sleep(1);
+        continue;
+      } else {
+        LOG(ERROR) << "Timed out waiting for the fuse-provided package.";
+        result = INSTALL_ERROR;
+        kill(child, SIGKILL);
+        break;
+      }
+    }
+
+    result = install_package(FUSE_SIDELOAD_HOST_PATHNAME, wipe_cache, false, 0 /*retry_count*/, ui);
+    break;
+  }
+
+  if (!waited) {
+    // Calling stat() on this magic filename signals the fuse
+    // filesystem to shut down.
+    struct stat sb;
+    stat(FUSE_SIDELOAD_HOST_EXIT_PATHNAME, &sb);
+
+    waitpid(child, &status, 0);
+  }
+
+  if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+    LOG(ERROR) << "Error exit from the fuse process: " << WEXITSTATUS(status);
+  }
+
+  ensure_path_unmounted(SDCARD_ROOT);
+  return result;
+}
diff --git a/install/include/install/adb_install.h b/install/include/install/adb_install.h
new file mode 100644
index 000000000..dbc824501
--- /dev/null
+++ b/install/include/install/adb_install.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+#pragma once
+
+#include <recovery_ui/ui.h>
+
+int apply_from_adb(bool* wipe_cache, RecoveryUI* ui);
diff --git a/install/include/install/fuse_sdcard_install.h b/install/include/install/fuse_sdcard_install.h
new file mode 100644
index 000000000..345aea45b
--- /dev/null
+++ b/install/include/install/fuse_sdcard_install.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include "recovery_ui/device.h"
+#include "recovery_ui/ui.h"
+
+int ApplyFromSdcard(Device* device, bool* wipe_cache, RecoveryUI* ui);
diff --git a/install/include/install/install.h b/install/include/install/install.h
new file mode 100644
index 000000000..74fb3d170
--- /dev/null
+++ b/install/include/install/install.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#pragma once
+
+#include <stddef.h>
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include <ziparchive/zip_archive.h>
+
+#include "package.h"
+#include "recovery_ui/ui.h"
+
+enum InstallResult {
+  INSTALL_SUCCESS,
+  INSTALL_ERROR,
+  INSTALL_CORRUPT,
+  INSTALL_NONE,
+  INSTALL_SKIPPED,
+  INSTALL_RETRY,
+  INSTALL_KEY_INTERRUPTED
+};
+
+enum class OtaType {
+  AB,
+  BLOCK,
+  BRICK,
+};
+
+// Installs the given update package. If INSTALL_SUCCESS is returned and *wipe_cache is true on
+// exit, caller should wipe the cache partition.
+int install_package(const std::string& package, bool* wipe_cache, bool needs_mount, int retry_count,
+                    RecoveryUI* ui);
+
+// Verifies the package by ota keys. Returns true if the package is verified successfully,
+// otherwise returns false.
+bool verify_package(Package* package, RecoveryUI* ui);
+
+// Reads meta data file of the package; parses each line in the format "key=value"; and writes the
+// result to |metadata|. Return true if succeed, otherwise return false.
+bool ReadMetadataFromPackage(ZipArchiveHandle zip, std::map<std::string, std::string>* metadata);
+
+// Reads the "recovery.wipe" entry in the zip archive returns a list of partitions to wipe.
+std::vector<std::string> GetWipePartitionList(Package* wipe_package);
+
+// Verifies the compatibility info in a Treble-compatible package. Returns true directly if the
+// entry doesn't exist.
+bool verify_package_compatibility(ZipArchiveHandle package_zip);
+
+// Checks if the the metadata in the OTA package has expected values. Returns 0 on success.
+// Mandatory checks: ota-type, pre-device and serial number(if presents)
+// AB OTA specific checks: pre-build version, fingerprint, timestamp.
+int CheckPackageMetadata(const std::map<std::string, std::string>& metadata, OtaType ota_type);
diff --git a/install/include/install/package.h b/install/include/install/package.h
new file mode 100644
index 000000000..cd44d10be
--- /dev/null
+++ b/install/include/install/package.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+#include <functional>
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <ziparchive/zip_archive.h>
+
+#include "verifier.h"
+
+// This class serves as a wrapper for an OTA update package. It aims to provide the common
+// interface for both packages loaded in memory and packages read from fd.
+class Package : public VerifierInterface {
+ public:
+  static std::unique_ptr<Package> CreateMemoryPackage(
+      const std::string& path, const std::function<void(float)>& set_progress);
+  static std::unique_ptr<Package> CreateMemoryPackage(
+      std::vector<uint8_t> content, const std::function<void(float)>& set_progress);
+  static std::unique_ptr<Package> CreateFilePackage(const std::string& path,
+                                                    const std::function<void(float)>& set_progress);
+
+  virtual ~Package() = default;
+
+  // Opens the package as a zip file and returns the ZipArchiveHandle.
+  virtual ZipArchiveHandle GetZipArchiveHandle() = 0;
+
+  // Updates the progress in fraction during package verification.
+  void SetProgress(float progress) override;
+
+ protected:
+  // An optional function to update the progress.
+  std::function<void(float)> set_progress_;
+};
diff --git a/install/include/install/verifier.h b/install/include/install/verifier.h
new file mode 100644
index 000000000..f9e947580
--- /dev/null
+++ b/install/include/install/verifier.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+#include <functional>
+#include <memory>
+#include <vector>
+
+#include <openssl/ec_key.h>
+#include <openssl/rsa.h>
+#include <openssl/sha.h>
+
+constexpr size_t MiB = 1024 * 1024;
+
+using HasherUpdateCallback = std::function<void(const uint8_t* addr, uint64_t size)>;
+
+struct RSADeleter {
+  void operator()(RSA* rsa) const {
+    RSA_free(rsa);
+  }
+};
+
+struct ECKEYDeleter {
+  void operator()(EC_KEY* ec_key) const {
+    EC_KEY_free(ec_key);
+  }
+};
+
+struct Certificate {
+  typedef enum {
+    KEY_TYPE_RSA,
+    KEY_TYPE_EC,
+  } KeyType;
+
+  Certificate(int hash_len_, KeyType key_type_, std::unique_ptr<RSA, RSADeleter>&& rsa_,
+              std::unique_ptr<EC_KEY, ECKEYDeleter>&& ec_)
+      : hash_len(hash_len_), key_type(key_type_), rsa(std::move(rsa_)), ec(std::move(ec_)) {}
+
+  // SHA_DIGEST_LENGTH (SHA-1) or SHA256_DIGEST_LENGTH (SHA-256)
+  int hash_len;
+  KeyType key_type;
+  std::unique_ptr<RSA, RSADeleter> rsa;
+  std::unique_ptr<EC_KEY, ECKEYDeleter> ec;
+};
+
+class VerifierInterface {
+ public:
+  virtual ~VerifierInterface() = default;
+
+  // Returns the package size in bytes.
+  virtual uint64_t GetPackageSize() const = 0;
+
+  // Reads |byte_count| data starting from |offset|, and puts the result in |buffer|.
+  virtual bool ReadFullyAtOffset(uint8_t* buffer, uint64_t byte_count, uint64_t offset) = 0;
+
+  // Updates the hash contexts for |length| bytes data starting from |start|.
+  virtual bool UpdateHashAtOffset(const std::vector<HasherUpdateCallback>& hashers, uint64_t start,
+                                  uint64_t length) = 0;
+
+  // Updates the progress in fraction during package verification.
+  virtual void SetProgress(float progress) = 0;
+};
+
+//  Looks for an RSA signature embedded in the .ZIP file comment given the path to the zip.
+//  Verifies that it matches one of the given public keys. Returns VERIFY_SUCCESS or
+//  VERIFY_FAILURE (if any error is encountered or no key matches the signature).
+int verify_file(VerifierInterface* package, const std::vector<Certificate>& keys);
+
+// Checks that the RSA key has a modulus of 2048 or 4096 bits long, and public exponent is 3 or
+// 65537.
+bool CheckRSAKey(const std::unique_ptr<RSA, RSADeleter>& rsa);
+
+// Checks that the field size of the curve for the EC key is 256 bits.
+bool CheckECKey(const std::unique_ptr<EC_KEY, ECKEYDeleter>& ec_key);
+
+// Parses a PEM-encoded x509 certificate from the given buffer and saves it into |cert|. Returns
+// false if there is a parsing failure or the signature's encryption algorithm is not supported.
+bool LoadCertificateFromBuffer(const std::vector<uint8_t>& pem_content, Certificate* cert);
+
+// Iterates over the zip entries with the suffix "x509.pem" and returns a list of recognized
+// certificates. Returns an empty list if we fail to parse any of the entries.
+std::vector<Certificate> LoadKeysFromZipfile(const std::string& zip_name);
+
+#define VERIFY_SUCCESS 0
+#define VERIFY_FAILURE 1
diff --git a/install/include/private/asn1_decoder.h b/install/include/private/asn1_decoder.h
new file mode 100644
index 000000000..e5337d9c4
--- /dev/null
+++ b/install/include/private/asn1_decoder.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#ifndef ASN1_DECODER_H_
+#define ASN1_DECODER_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+class asn1_context {
+ public:
+  asn1_context(const uint8_t* buffer, size_t length) : p_(buffer), length_(length), app_type_(0) {}
+  int asn1_constructed_type() const;
+  asn1_context* asn1_constructed_get();
+  bool asn1_constructed_skip_all();
+  asn1_context* asn1_sequence_get();
+  asn1_context* asn1_set_get();
+  bool asn1_sequence_next();
+  bool asn1_oid_get(const uint8_t** oid, size_t* length);
+  bool asn1_octet_string_get(const uint8_t** octet_string, size_t* length);
+
+ private:
+  static constexpr int kMaskConstructed = 0xE0;
+  static constexpr int kMaskTag = 0x7F;
+  static constexpr int kMaskAppType = 0x1F;
+
+  static constexpr int kTagOctetString = 0x04;
+  static constexpr int kTagOid = 0x06;
+  static constexpr int kTagSequence = 0x30;
+  static constexpr int kTagSet = 0x31;
+  static constexpr int kTagConstructed = 0xA0;
+
+  int peek_byte() const;
+  int get_byte();
+  bool skip_bytes(size_t num_skip);
+  bool decode_length(size_t* out_len);
+
+  const uint8_t* p_;
+  size_t length_;
+  int app_type_;
+};
+
+#endif /* ASN1_DECODER_H_ */
diff --git a/install/include/private/setup_commands.h b/install/include/private/setup_commands.h
new file mode 100644
index 000000000..7fdc741d6
--- /dev/null
+++ b/install/include/private/setup_commands.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+// Private headers exposed for testing purpose only.
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include <ziparchive/zip_archive.h>
+
+// Sets up the commands for a non-A/B update. Extracts the updater binary from the open zip archive
+// |zip| located at |package|. Stores the command line that should be called into |cmd|. The
+// |status_fd| is the file descriptor the child process should use to report back the progress of
+// the update.
+int SetUpNonAbUpdateCommands(const std::string& package, ZipArchiveHandle zip, int retry_count,
+                             int status_fd, std::vector<std::string>* cmd);
+
+// Sets up the commands for an A/B update. Extracts the needed entries from the open zip archive
+// |zip| located at |package|. Stores the command line that should be called into |cmd|. The
+// |status_fd| is the file descriptor the child process should use to report back the progress of
+// the update. Note that since this applies to the sideloading flow only, it takes one less
+// parameter |retry_count| than the non-A/B version.
+int SetUpAbUpdateCommands(const std::string& package, ZipArchiveHandle zip, int status_fd,
+                          std::vector<std::string>* cmd);
diff --git a/install/install.cpp b/install/install.cpp
new file mode 100644
index 000000000..a1124c361
--- /dev/null
+++ b/install/install.cpp
@@ -0,0 +1,730 @@
+/*
+ * Copyright (C) 2007 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.
+ */
+
+#include "install/install.h"
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <atomic>
+#include <chrono>
+#include <condition_variable>
+#include <functional>
+#include <limits>
+#include <mutex>
+#include <thread>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/parsedouble.h>
+#include <android-base/parseint.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+#include <vintf/VintfObjectRecovery.h>
+
+#include "install/package.h"
+#include "install/verifier.h"
+#include "otautil/error_code.h"
+#include "otautil/paths.h"
+#include "otautil/roots.h"
+#include "otautil/sysutil.h"
+#include "otautil/thermalutil.h"
+#include "private/setup_commands.h"
+#include "recovery_ui/ui.h"
+
+using namespace std::chrono_literals;
+
+static constexpr int kRecoveryApiVersion = 3;
+// Assert the version defined in code and in Android.mk are consistent.
+static_assert(kRecoveryApiVersion == RECOVERY_API_VERSION, "Mismatching recovery API versions.");
+
+// Default allocation of progress bar segments to operations
+static constexpr int VERIFICATION_PROGRESS_TIME = 60;
+static constexpr float VERIFICATION_PROGRESS_FRACTION = 0.25;
+
+static std::condition_variable finish_log_temperature;
+
+bool ReadMetadataFromPackage(ZipArchiveHandle zip, std::map<std::string, std::string>* metadata) {
+  CHECK(metadata != nullptr);
+
+  static constexpr const char* METADATA_PATH = "META-INF/com/android/metadata";
+  ZipString path(METADATA_PATH);
+  ZipEntry entry;
+  if (FindEntry(zip, path, &entry) != 0) {
+    LOG(ERROR) << "Failed to find " << METADATA_PATH;
+    return false;
+  }
+
+  uint32_t length = entry.uncompressed_length;
+  std::string metadata_string(length, '\0');
+  int32_t err =
+      ExtractToMemory(zip, &entry, reinterpret_cast<uint8_t*>(&metadata_string[0]), length);
+  if (err != 0) {
+    LOG(ERROR) << "Failed to extract " << METADATA_PATH << ": " << ErrorCodeString(err);
+    return false;
+  }
+
+  for (const std::string& line : android::base::Split(metadata_string, "\n")) {
+    size_t eq = line.find('=');
+    if (eq != std::string::npos) {
+      metadata->emplace(android::base::Trim(line.substr(0, eq)),
+                        android::base::Trim(line.substr(eq + 1)));
+    }
+  }
+
+  return true;
+}
+
+// Gets the value for the given key in |metadata|. Returns an emtpy string if the key isn't
+// present.
+static std::string get_value(const std::map<std::string, std::string>& metadata,
+                             const std::string& key) {
+  const auto& it = metadata.find(key);
+  return (it == metadata.end()) ? "" : it->second;
+}
+
+static std::string OtaTypeToString(OtaType type) {
+  switch (type) {
+    case OtaType::AB:
+      return "AB";
+    case OtaType::BLOCK:
+      return "BLOCK";
+    case OtaType::BRICK:
+      return "BRICK";
+  }
+}
+
+// Read the build.version.incremental of src/tgt from the metadata and log it to last_install.
+static void ReadSourceTargetBuild(const std::map<std::string, std::string>& metadata,
+                                  std::vector<std::string>* log_buffer) {
+  // Examples of the pre-build and post-build strings in metadata:
+  //   pre-build-incremental=2943039
+  //   post-build-incremental=2951741
+  auto source_build = get_value(metadata, "pre-build-incremental");
+  if (!source_build.empty()) {
+    log_buffer->push_back("source_build: " + source_build);
+  }
+
+  auto target_build = get_value(metadata, "post-build-incremental");
+  if (!target_build.empty()) {
+    log_buffer->push_back("target_build: " + target_build);
+  }
+}
+
+// Checks the build version, fingerprint and timestamp in the metadata of the A/B package.
+// Downgrading is not allowed unless explicitly enabled in the package and only for
+// incremental packages.
+static int CheckAbSpecificMetadata(const std::map<std::string, std::string>& metadata) {
+  // Incremental updates should match the current build.
+  auto device_pre_build = android::base::GetProperty("ro.build.version.incremental", "");
+  auto pkg_pre_build = get_value(metadata, "pre-build-incremental");
+  if (!pkg_pre_build.empty() && pkg_pre_build != device_pre_build) {
+    LOG(ERROR) << "Package is for source build " << pkg_pre_build << " but expected "
+               << device_pre_build;
+    return INSTALL_ERROR;
+  }
+
+  auto device_fingerprint = android::base::GetProperty("ro.build.fingerprint", "");
+  auto pkg_pre_build_fingerprint = get_value(metadata, "pre-build");
+  if (!pkg_pre_build_fingerprint.empty() && pkg_pre_build_fingerprint != device_fingerprint) {
+    LOG(ERROR) << "Package is for source build " << pkg_pre_build_fingerprint << " but expected "
+               << device_fingerprint;
+    return INSTALL_ERROR;
+  }
+
+  // Check for downgrade version.
+  int64_t build_timestamp =
+      android::base::GetIntProperty("ro.build.date.utc", std::numeric_limits<int64_t>::max());
+  int64_t pkg_post_timestamp = 0;
+  // We allow to full update to the same version we are running, in case there
+  // is a problem with the current copy of that version.
+  auto pkg_post_timestamp_string = get_value(metadata, "post-timestamp");
+  if (pkg_post_timestamp_string.empty() ||
+      !android::base::ParseInt(pkg_post_timestamp_string, &pkg_post_timestamp) ||
+      pkg_post_timestamp < build_timestamp) {
+    if (get_value(metadata, "ota-downgrade") != "yes") {
+      LOG(ERROR) << "Update package is older than the current build, expected a build "
+                    "newer than timestamp "
+                 << build_timestamp << " but package has timestamp " << pkg_post_timestamp
+                 << " and downgrade not allowed.";
+      return INSTALL_ERROR;
+    }
+    if (pkg_pre_build_fingerprint.empty()) {
+      LOG(ERROR) << "Downgrade package must have a pre-build version set, not allowed.";
+      return INSTALL_ERROR;
+    }
+  }
+
+  return 0;
+}
+
+int CheckPackageMetadata(const std::map<std::string, std::string>& metadata, OtaType ota_type) {
+  auto package_ota_type = get_value(metadata, "ota-type");
+  auto expected_ota_type = OtaTypeToString(ota_type);
+  if (ota_type != OtaType::AB && ota_type != OtaType::BRICK) {
+    LOG(INFO) << "Skip package metadata check for ota type " << expected_ota_type;
+    return 0;
+  }
+
+  if (package_ota_type != expected_ota_type) {
+    LOG(ERROR) << "Unexpected ota package type, expects " << expected_ota_type << ", actual "
+               << package_ota_type;
+    return INSTALL_ERROR;
+  }
+
+  auto device = android::base::GetProperty("ro.product.device", "");
+  auto pkg_device = get_value(metadata, "pre-device");
+  if (pkg_device != device || pkg_device.empty()) {
+    LOG(ERROR) << "Package is for product " << pkg_device << " but expected " << device;
+    return INSTALL_ERROR;
+  }
+
+  // We allow the package to not have any serialno; and we also allow it to carry multiple serial
+  // numbers split by "|"; e.g. serialno=serialno1|serialno2|serialno3 ... We will fail the
+  // verification if the device's serialno doesn't match any of these carried numbers.
+  auto pkg_serial_no = get_value(metadata, "serialno");
+  if (!pkg_serial_no.empty()) {
+    auto device_serial_no = android::base::GetProperty("ro.serialno", "");
+    bool serial_number_match = false;
+    for (const auto& number : android::base::Split(pkg_serial_no, "|")) {
+      if (device_serial_no == android::base::Trim(number)) {
+        serial_number_match = true;
+      }
+    }
+    if (!serial_number_match) {
+      LOG(ERROR) << "Package is for serial " << pkg_serial_no;
+      return INSTALL_ERROR;
+    }
+  }
+
+  if (ota_type == OtaType::AB) {
+    return CheckAbSpecificMetadata(metadata);
+  }
+
+  return 0;
+}
+
+int SetUpAbUpdateCommands(const std::string& package, ZipArchiveHandle zip, int status_fd,
+                          std::vector<std::string>* cmd) {
+  CHECK(cmd != nullptr);
+
+  // For A/B updates we extract the payload properties to a buffer and obtain the RAW payload offset
+  // in the zip file.
+  static constexpr const char* AB_OTA_PAYLOAD_PROPERTIES = "payload_properties.txt";
+  ZipString property_name(AB_OTA_PAYLOAD_PROPERTIES);
+  ZipEntry properties_entry;
+  if (FindEntry(zip, property_name, &properties_entry) != 0) {
+    LOG(ERROR) << "Failed to find " << AB_OTA_PAYLOAD_PROPERTIES;
+    return INSTALL_CORRUPT;
+  }
+  uint32_t properties_entry_length = properties_entry.uncompressed_length;
+  std::vector<uint8_t> payload_properties(properties_entry_length);
+  int32_t err =
+      ExtractToMemory(zip, &properties_entry, payload_properties.data(), properties_entry_length);
+  if (err != 0) {
+    LOG(ERROR) << "Failed to extract " << AB_OTA_PAYLOAD_PROPERTIES << ": " << ErrorCodeString(err);
+    return INSTALL_CORRUPT;
+  }
+
+  static constexpr const char* AB_OTA_PAYLOAD = "payload.bin";
+  ZipString payload_name(AB_OTA_PAYLOAD);
+  ZipEntry payload_entry;
+  if (FindEntry(zip, payload_name, &payload_entry) != 0) {
+    LOG(ERROR) << "Failed to find " << AB_OTA_PAYLOAD;
+    return INSTALL_CORRUPT;
+  }
+  long payload_offset = payload_entry.offset;
+  *cmd = {
+    "/system/bin/update_engine_sideload",
+    "--payload=file://" + package,
+    android::base::StringPrintf("--offset=%ld", payload_offset),
+    "--headers=" + std::string(payload_properties.begin(), payload_properties.end()),
+    android::base::StringPrintf("--status_fd=%d", status_fd),
+  };
+  return 0;
+}
+
+int SetUpNonAbUpdateCommands(const std::string& package, ZipArchiveHandle zip, int retry_count,
+                             int status_fd, std::vector<std::string>* cmd) {
+  CHECK(cmd != nullptr);
+
+  // In non-A/B updates we extract the update binary from the package.
+  static constexpr const char* UPDATE_BINARY_NAME = "META-INF/com/google/android/update-binary";
+  ZipString binary_name(UPDATE_BINARY_NAME);
+  ZipEntry binary_entry;
+  if (FindEntry(zip, binary_name, &binary_entry) != 0) {
+    LOG(ERROR) << "Failed to find update binary " << UPDATE_BINARY_NAME;
+    return INSTALL_CORRUPT;
+  }
+
+  const std::string binary_path = Paths::Get().temporary_update_binary();
+  unlink(binary_path.c_str());
+  android::base::unique_fd fd(
+      open(binary_path.c_str(), O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, 0755));
+  if (fd == -1) {
+    PLOG(ERROR) << "Failed to create " << binary_path;
+    return INSTALL_ERROR;
+  }
+
+  int32_t error = ExtractEntryToFile(zip, &binary_entry, fd);
+  if (error != 0) {
+    LOG(ERROR) << "Failed to extract " << UPDATE_BINARY_NAME << ": " << ErrorCodeString(error);
+    return INSTALL_ERROR;
+  }
+
+  // When executing the update binary contained in the package, the arguments passed are:
+  //   - the version number for this interface
+  //   - an FD to which the program can write in order to update the progress bar.
+  //   - the name of the package zip file.
+  //   - an optional argument "retry" if this update is a retry of a failed update attempt.
+  *cmd = {
+    binary_path,
+    std::to_string(kRecoveryApiVersion),
+    std::to_string(status_fd),
+    package,
+  };
+  if (retry_count > 0) {
+    cmd->push_back("retry");
+  }
+  return 0;
+}
+
+static void log_max_temperature(int* max_temperature, const std::atomic<bool>& logger_finished) {
+  CHECK(max_temperature != nullptr);
+  std::mutex mtx;
+  std::unique_lock<std::mutex> lck(mtx);
+  while (!logger_finished.load() &&
+         finish_log_temperature.wait_for(lck, 20s) == std::cv_status::timeout) {
+    *max_temperature = std::max(*max_temperature, GetMaxValueFromThermalZone());
+  }
+}
+
+// If the package contains an update binary, extract it and run it.
+static int try_update_binary(const std::string& package, ZipArchiveHandle zip, bool* wipe_cache,
+                             std::vector<std::string>* log_buffer, int retry_count,
+                             int* max_temperature, RecoveryUI* ui) {
+  std::map<std::string, std::string> metadata;
+  if (!ReadMetadataFromPackage(zip, &metadata)) {
+    LOG(ERROR) << "Failed to parse metadata in the zip file";
+    return INSTALL_CORRUPT;
+  }
+
+  bool is_ab = android::base::GetBoolProperty("ro.build.ab_update", false);
+  // Verifies against the metadata in the package first.
+  if (int check_status = is_ab ? CheckPackageMetadata(metadata, OtaType::AB) : 0;
+      check_status != 0) {
+    log_buffer->push_back(android::base::StringPrintf("error: %d", kUpdateBinaryCommandFailure));
+    return check_status;
+  }
+
+  ReadSourceTargetBuild(metadata, log_buffer);
+
+  // The updater in child process writes to the pipe to communicate with recovery.
+  android::base::unique_fd pipe_read, pipe_write;
+  // Explicitly disable O_CLOEXEC using 0 as the flags (last) parameter to Pipe
+  // so that the child updater process will recieve a non-closed fd.
+  if (!android::base::Pipe(&pipe_read, &pipe_write, 0)) {
+    PLOG(ERROR) << "Failed to create pipe for updater-recovery communication";
+    return INSTALL_CORRUPT;
+  }
+
+  // The updater-recovery communication protocol.
+  //
+  //   progress <frac> <secs>
+  //       fill up the next <frac> part of of the progress bar over <secs> seconds. If <secs> is
+  //       zero, use `set_progress` commands to manually control the progress of this segment of the
+  //       bar.
+  //
+  //   set_progress <frac>
+  //       <frac> should be between 0.0 and 1.0; sets the progress bar within the segment defined by
+  //       the most recent progress command.
+  //
+  //   ui_print <string>
+  //       display <string> on the screen.
+  //
+  //   wipe_cache
+  //       a wipe of cache will be performed following a successful installation.
+  //
+  //   clear_display
+  //       turn off the text display.
+  //
+  //   enable_reboot
+  //       packages can explicitly request that they want the user to be able to reboot during
+  //       installation (useful for debugging packages that don't exit).
+  //
+  //   retry_update
+  //       updater encounters some issue during the update. It requests a reboot to retry the same
+  //       package automatically.
+  //
+  //   log <string>
+  //       updater requests logging the string (e.g. cause of the failure).
+  //
+
+  std::vector<std::string> args;
+  if (int update_status =
+          is_ab ? SetUpAbUpdateCommands(package, zip, pipe_write.get(), &args)
+                : SetUpNonAbUpdateCommands(package, zip, retry_count, pipe_write.get(), &args);
+      update_status != 0) {
+    log_buffer->push_back(android::base::StringPrintf("error: %d", kUpdateBinaryCommandFailure));
+    return update_status;
+  }
+
+  pid_t pid = fork();
+  if (pid == -1) {
+    PLOG(ERROR) << "Failed to fork update binary";
+    log_buffer->push_back(android::base::StringPrintf("error: %d", kForkUpdateBinaryFailure));
+    return INSTALL_ERROR;
+  }
+
+  if (pid == 0) {
+    umask(022);
+    pipe_read.reset();
+
+    // Convert the std::string vector to a NULL-terminated char* vector suitable for execv.
+    auto chr_args = StringVectorToNullTerminatedArray(args);
+    execv(chr_args[0], chr_args.data());
+    // We shouldn't use LOG/PLOG in the forked process, since they may cause the child process to
+    // hang. This deadlock results from an improperly copied mutex in the ui functions.
+    // (Bug: 34769056)
+    fprintf(stdout, "E:Can't run %s (%s)\n", chr_args[0], strerror(errno));
+    _exit(EXIT_FAILURE);
+  }
+  pipe_write.reset();
+
+  std::atomic<bool> logger_finished(false);
+  std::thread temperature_logger(log_max_temperature, max_temperature, std::ref(logger_finished));
+
+  *wipe_cache = false;
+  bool retry_update = false;
+
+  char buffer[1024];
+  FILE* from_child = android::base::Fdopen(std::move(pipe_read), "r");
+  while (fgets(buffer, sizeof(buffer), from_child) != nullptr) {
+    std::string line(buffer);
+    size_t space = line.find_first_of(" \n");
+    std::string command(line.substr(0, space));
+    if (command.empty()) continue;
+
+    // Get rid of the leading and trailing space and/or newline.
+    std::string args = space == std::string::npos ? "" : android::base::Trim(line.substr(space));
+
+    if (command == "progress") {
+      std::vector<std::string> tokens = android::base::Split(args, " ");
+      double fraction;
+      int seconds;
+      if (tokens.size() == 2 && android::base::ParseDouble(tokens[0].c_str(), &fraction) &&
+          android::base::ParseInt(tokens[1], &seconds)) {
+        ui->ShowProgress(fraction * (1 - VERIFICATION_PROGRESS_FRACTION), seconds);
+      } else {
+        LOG(ERROR) << "invalid \"progress\" parameters: " << line;
+      }
+    } else if (command == "set_progress") {
+      std::vector<std::string> tokens = android::base::Split(args, " ");
+      double fraction;
+      if (tokens.size() == 1 && android::base::ParseDouble(tokens[0].c_str(), &fraction)) {
+        ui->SetProgress(fraction);
+      } else {
+        LOG(ERROR) << "invalid \"set_progress\" parameters: " << line;
+      }
+    } else if (command == "ui_print") {
+      ui->PrintOnScreenOnly("%s\n", args.c_str());
+      fflush(stdout);
+    } else if (command == "wipe_cache") {
+      *wipe_cache = true;
+    } else if (command == "clear_display") {
+      ui->SetBackground(RecoveryUI::NONE);
+    } else if (command == "enable_reboot") {
+      // packages can explicitly request that they want the user
+      // to be able to reboot during installation (useful for
+      // debugging packages that don't exit).
+      ui->SetEnableReboot(true);
+    } else if (command == "retry_update") {
+      retry_update = true;
+    } else if (command == "log") {
+      if (!args.empty()) {
+        // Save the logging request from updater and write to last_install later.
+        log_buffer->push_back(args);
+      } else {
+        LOG(ERROR) << "invalid \"log\" parameters: " << line;
+      }
+    } else {
+      LOG(ERROR) << "unknown command [" << command << "]";
+    }
+  }
+  fclose(from_child);
+
+  int status;
+  waitpid(pid, &status, 0);
+
+  logger_finished.store(true);
+  finish_log_temperature.notify_one();
+  temperature_logger.join();
+
+  if (retry_update) {
+    return INSTALL_RETRY;
+  }
+  if (WIFEXITED(status)) {
+    if (WEXITSTATUS(status) != EXIT_SUCCESS) {
+      LOG(ERROR) << "Error in " << package << " (status " << WEXITSTATUS(status) << ")";
+      return INSTALL_ERROR;
+    }
+  } else if (WIFSIGNALED(status)) {
+    LOG(ERROR) << "Error in " << package << " (killed by signal " << WTERMSIG(status) << ")";
+    return INSTALL_ERROR;
+  } else {
+    LOG(FATAL) << "Invalid status code " << status;
+  }
+
+  return INSTALL_SUCCESS;
+}
+
+// Verifes the compatibility info in a Treble-compatible package. Returns true directly if the
+// entry doesn't exist. Note that the compatibility info is packed in a zip file inside the OTA
+// package.
+bool verify_package_compatibility(ZipArchiveHandle package_zip) {
+  LOG(INFO) << "Verifying package compatibility...";
+
+  static constexpr const char* COMPATIBILITY_ZIP_ENTRY = "compatibility.zip";
+  ZipString compatibility_entry_name(COMPATIBILITY_ZIP_ENTRY);
+  ZipEntry compatibility_entry;
+  if (FindEntry(package_zip, compatibility_entry_name, &compatibility_entry) != 0) {
+    LOG(INFO) << "Package doesn't contain " << COMPATIBILITY_ZIP_ENTRY << " entry";
+    return true;
+  }
+
+  std::string zip_content(compatibility_entry.uncompressed_length, '\0');
+  int32_t ret;
+  if ((ret = ExtractToMemory(package_zip, &compatibility_entry,
+                             reinterpret_cast<uint8_t*>(&zip_content[0]),
+                             compatibility_entry.uncompressed_length)) != 0) {
+    LOG(ERROR) << "Failed to read " << COMPATIBILITY_ZIP_ENTRY << ": " << ErrorCodeString(ret);
+    return false;
+  }
+
+  ZipArchiveHandle zip_handle;
+  ret = OpenArchiveFromMemory(static_cast<void*>(const_cast<char*>(zip_content.data())),
+                              zip_content.size(), COMPATIBILITY_ZIP_ENTRY, &zip_handle);
+  if (ret != 0) {
+    LOG(ERROR) << "Failed to OpenArchiveFromMemory: " << ErrorCodeString(ret);
+    return false;
+  }
+
+  // Iterate all the entries inside COMPATIBILITY_ZIP_ENTRY and read the contents.
+  void* cookie;
+  ret = StartIteration(zip_handle, &cookie, nullptr, nullptr);
+  if (ret != 0) {
+    LOG(ERROR) << "Failed to start iterating zip entries: " << ErrorCodeString(ret);
+    CloseArchive(zip_handle);
+    return false;
+  }
+  std::unique_ptr<void, decltype(&EndIteration)> guard(cookie, EndIteration);
+
+  std::vector<std::string> compatibility_info;
+  ZipEntry info_entry;
+  ZipString info_name;
+  while (Next(cookie, &info_entry, &info_name) == 0) {
+    std::string content(info_entry.uncompressed_length, '\0');
+    int32_t ret = ExtractToMemory(zip_handle, &info_entry, reinterpret_cast<uint8_t*>(&content[0]),
+                                  info_entry.uncompressed_length);
+    if (ret != 0) {
+      LOG(ERROR) << "Failed to read " << info_name.name << ": " << ErrorCodeString(ret);
+      CloseArchive(zip_handle);
+      return false;
+    }
+    compatibility_info.emplace_back(std::move(content));
+  }
+  CloseArchive(zip_handle);
+
+  // VintfObjectRecovery::CheckCompatibility returns zero on success.
+  std::string err;
+  int result = android::vintf::VintfObjectRecovery::CheckCompatibility(compatibility_info, &err);
+  if (result == 0) {
+    return true;
+  }
+
+  LOG(ERROR) << "Failed to verify package compatibility (result " << result << "): " << err;
+  return false;
+}
+
+static int really_install_package(const std::string& path, bool* wipe_cache, bool needs_mount,
+                                  std::vector<std::string>* log_buffer, int retry_count,
+                                  int* max_temperature, RecoveryUI* ui) {
+  ui->SetBackground(RecoveryUI::INSTALLING_UPDATE);
+  ui->Print("Finding update package...\n");
+  // Give verification half the progress bar...
+  ui->SetProgressType(RecoveryUI::DETERMINATE);
+  ui->ShowProgress(VERIFICATION_PROGRESS_FRACTION, VERIFICATION_PROGRESS_TIME);
+  LOG(INFO) << "Update location: " << path;
+
+  // Map the update package into memory.
+  ui->Print("Opening update package...\n");
+
+  if (needs_mount) {
+    if (path[0] == '@') {
+      ensure_path_mounted(path.substr(1));
+    } else {
+      ensure_path_mounted(path);
+    }
+  }
+
+  auto package = Package::CreateMemoryPackage(
+      path, std::bind(&RecoveryUI::SetProgress, ui, std::placeholders::_1));
+  if (!package) {
+    log_buffer->push_back(android::base::StringPrintf("error: %d", kMapFileFailure));
+    return INSTALL_CORRUPT;
+  }
+
+  // Verify package.
+  if (!verify_package(package.get(), ui)) {
+    log_buffer->push_back(android::base::StringPrintf("error: %d", kZipVerificationFailure));
+    return INSTALL_CORRUPT;
+  }
+
+  // Try to open the package.
+  ZipArchiveHandle zip = package->GetZipArchiveHandle();
+  if (!zip) {
+    log_buffer->push_back(android::base::StringPrintf("error: %d", kZipOpenFailure));
+    return INSTALL_CORRUPT;
+  }
+
+  // Additionally verify the compatibility of the package if it's a fresh install.
+  if (retry_count == 0 && !verify_package_compatibility(zip)) {
+    log_buffer->push_back(android::base::StringPrintf("error: %d", kPackageCompatibilityFailure));
+    return INSTALL_CORRUPT;
+  }
+
+  // Verify and install the contents of the package.
+  ui->Print("Installing update...\n");
+  if (retry_count > 0) {
+    ui->Print("Retry attempt: %d\n", retry_count);
+  }
+  ui->SetEnableReboot(false);
+  int result =
+      try_update_binary(path, zip, wipe_cache, log_buffer, retry_count, max_temperature, ui);
+  ui->SetEnableReboot(true);
+  ui->Print("\n");
+
+  return result;
+}
+
+int install_package(const std::string& path, bool* wipe_cache, bool needs_mount, int retry_count,
+                    RecoveryUI* ui) {
+  CHECK(!path.empty());
+  CHECK(wipe_cache != nullptr);
+
+  auto start = std::chrono::system_clock::now();
+
+  int start_temperature = GetMaxValueFromThermalZone();
+  int max_temperature = start_temperature;
+
+  int result;
+  std::vector<std::string> log_buffer;
+  if (setup_install_mounts() != 0) {
+    LOG(ERROR) << "failed to set up expected mounts for install; aborting";
+    result = INSTALL_ERROR;
+  } else {
+    result = really_install_package(path, wipe_cache, needs_mount, &log_buffer, retry_count,
+                                    &max_temperature, ui);
+  }
+
+  // Measure the time spent to apply OTA update in seconds.
+  std::chrono::duration<double> duration = std::chrono::system_clock::now() - start;
+  int time_total = static_cast<int>(duration.count());
+
+  bool has_cache = volume_for_mount_point("/cache") != nullptr;
+  // Skip logging the uncrypt_status on devices without /cache.
+  if (has_cache) {
+    static constexpr const char* UNCRYPT_STATUS = "/cache/recovery/uncrypt_status";
+    if (ensure_path_mounted(UNCRYPT_STATUS) != 0) {
+      LOG(WARNING) << "Can't mount " << UNCRYPT_STATUS;
+    } else {
+      std::string uncrypt_status;
+      if (!android::base::ReadFileToString(UNCRYPT_STATUS, &uncrypt_status)) {
+        PLOG(WARNING) << "failed to read uncrypt status";
+      } else if (!android::base::StartsWith(uncrypt_status, "uncrypt_")) {
+        LOG(WARNING) << "corrupted uncrypt_status: " << uncrypt_status;
+      } else {
+        log_buffer.push_back(android::base::Trim(uncrypt_status));
+      }
+    }
+  }
+
+  // The first two lines need to be the package name and install result.
+  std::vector<std::string> log_header = {
+    path,
+    result == INSTALL_SUCCESS ? "1" : "0",
+    "time_total: " + std::to_string(time_total),
+    "retry: " + std::to_string(retry_count),
+  };
+
+  int end_temperature = GetMaxValueFromThermalZone();
+  max_temperature = std::max(end_temperature, max_temperature);
+  if (start_temperature > 0) {
+    log_buffer.push_back("temperature_start: " + std::to_string(start_temperature));
+  }
+  if (end_temperature > 0) {
+    log_buffer.push_back("temperature_end: " + std::to_string(end_temperature));
+  }
+  if (max_temperature > 0) {
+    log_buffer.push_back("temperature_max: " + std::to_string(max_temperature));
+  }
+
+  std::string log_content =
+      android::base::Join(log_header, "\n") + "\n" + android::base::Join(log_buffer, "\n") + "\n";
+  const std::string& install_file = Paths::Get().temporary_install_file();
+  if (!android::base::WriteStringToFile(log_content, install_file)) {
+    PLOG(ERROR) << "failed to write " << install_file;
+  }
+
+  // Write a copy into last_log.
+  LOG(INFO) << log_content;
+
+  return result;
+}
+
+bool verify_package(Package* package, RecoveryUI* ui) {
+  static constexpr const char* CERTIFICATE_ZIP_FILE = "/system/etc/security/otacerts.zip";
+  std::vector<Certificate> loaded_keys = LoadKeysFromZipfile(CERTIFICATE_ZIP_FILE);
+  if (loaded_keys.empty()) {
+    LOG(ERROR) << "Failed to load keys";
+    return false;
+  }
+  LOG(INFO) << loaded_keys.size() << " key(s) loaded from " << CERTIFICATE_ZIP_FILE;
+
+  // Verify package.
+  ui->Print("Verifying update package...\n");
+  auto t0 = std::chrono::system_clock::now();
+  int err = verify_file(package, loaded_keys);
+  std::chrono::duration<double> duration = std::chrono::system_clock::now() - t0;
+  ui->Print("Update package verification took %.1f s (result %d).\n", duration.count(), err);
+  if (err != VERIFY_SUCCESS) {
+    LOG(ERROR) << "Signature verification failed";
+    LOG(ERROR) << "error: " << kZipVerificationFailure;
+    return false;
+  }
+  return true;
+}
diff --git a/install/package.cpp b/install/package.cpp
new file mode 100644
index 000000000..4402f4855
--- /dev/null
+++ b/install/package.cpp
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include "install/package.h"
+
+#include <string.h>
+#include <unistd.h>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+
+#include "otautil/error_code.h"
+#include "otautil/sysutil.h"
+
+// This class wraps the package in memory, i.e. a memory mapped package, or a package loaded
+// to a string/vector.
+class MemoryPackage : public Package {
+ public:
+  // Constructs the class from a file. We will memory maps the file later.
+  MemoryPackage(const std::string& path, std::unique_ptr<MemMapping> map,
+                const std::function<void(float)>& set_progress);
+
+  // Constructs the class from the package bytes in |content|.
+  MemoryPackage(std::vector<uint8_t> content, const std::function<void(float)>& set_progress);
+
+  ~MemoryPackage() override;
+
+  // Memory maps the package file if necessary. Initializes the start address and size of the
+  // package.
+  uint64_t GetPackageSize() const override {
+    return package_size_;
+  }
+
+  bool ReadFullyAtOffset(uint8_t* buffer, uint64_t byte_count, uint64_t offset) override;
+
+  ZipArchiveHandle GetZipArchiveHandle() override;
+
+  bool UpdateHashAtOffset(const std::vector<HasherUpdateCallback>& hashers, uint64_t start,
+                          uint64_t length) override;
+
+ private:
+  const uint8_t* addr_;    // Start address of the package in memory.
+  uint64_t package_size_;  // Package size in bytes.
+
+  // The memory mapped package.
+  std::unique_ptr<MemMapping> map_;
+  // A copy of the package content, valid only if we create the class with the exact bytes of
+  // the package.
+  std::vector<uint8_t> package_content_;
+  // The physical path to the package, empty if we create the class with the package content.
+  std::string path_;
+
+  // The ZipArchiveHandle of the package.
+  ZipArchiveHandle zip_handle_;
+};
+
+void Package::SetProgress(float progress) {
+  if (set_progress_) {
+    set_progress_(progress);
+  }
+}
+
+class FilePackage : public Package {
+ public:
+  FilePackage(android::base::unique_fd&& fd, uint64_t file_size, const std::string& path,
+              const std::function<void(float)>& set_progress);
+
+  ~FilePackage() override;
+
+  uint64_t GetPackageSize() const override {
+    return package_size_;
+  }
+
+  bool ReadFullyAtOffset(uint8_t* buffer, uint64_t byte_count, uint64_t offset) override;
+
+  ZipArchiveHandle GetZipArchiveHandle() override;
+
+  bool UpdateHashAtOffset(const std::vector<HasherUpdateCallback>& hashers, uint64_t start,
+                          uint64_t length) override;
+
+ private:
+  android::base::unique_fd fd_;  // The underlying fd to the open package.
+  uint64_t package_size_;
+  std::string path_;  // The physical path to the package.
+
+  ZipArchiveHandle zip_handle_;
+};
+
+std::unique_ptr<Package> Package::CreateMemoryPackage(
+    const std::string& path, const std::function<void(float)>& set_progress) {
+  std::unique_ptr<MemMapping> mmap = std::make_unique<MemMapping>();
+  if (!mmap->MapFile(path)) {
+    LOG(ERROR) << "failed to map file";
+    return nullptr;
+  }
+
+  return std::make_unique<MemoryPackage>(path, std::move(mmap), set_progress);
+}
+
+std::unique_ptr<Package> Package::CreateFilePackage(
+    const std::string& path, const std::function<void(float)>& set_progress) {
+  android::base::unique_fd fd(open(path.c_str(), O_RDONLY));
+  if (fd == -1) {
+    PLOG(ERROR) << "Failed to open " << path;
+    return nullptr;
+  }
+
+  off64_t file_size = lseek64(fd.get(), 0, SEEK_END);
+  if (file_size == -1) {
+    PLOG(ERROR) << "Failed to get the package size";
+    return nullptr;
+  }
+
+  return std::make_unique<FilePackage>(std::move(fd), file_size, path, set_progress);
+}
+
+std::unique_ptr<Package> Package::CreateMemoryPackage(
+    std::vector<uint8_t> content, const std::function<void(float)>& set_progress) {
+  return std::make_unique<MemoryPackage>(std::move(content), set_progress);
+}
+
+MemoryPackage::MemoryPackage(const std::string& path, std::unique_ptr<MemMapping> map,
+                             const std::function<void(float)>& set_progress)
+    : map_(std::move(map)), path_(path), zip_handle_(nullptr) {
+  addr_ = map_->addr;
+  package_size_ = map_->length;
+  set_progress_ = set_progress;
+}
+
+MemoryPackage::MemoryPackage(std::vector<uint8_t> content,
+                             const std::function<void(float)>& set_progress)
+    : package_content_(std::move(content)), zip_handle_(nullptr) {
+  CHECK(!package_content_.empty());
+  addr_ = package_content_.data();
+  package_size_ = package_content_.size();
+  set_progress_ = set_progress;
+}
+
+MemoryPackage::~MemoryPackage() {
+  if (zip_handle_) {
+    CloseArchive(zip_handle_);
+  }
+}
+
+bool MemoryPackage::ReadFullyAtOffset(uint8_t* buffer, uint64_t byte_count, uint64_t offset) {
+  if (byte_count > package_size_ || offset > package_size_ - byte_count) {
+    LOG(ERROR) << "Out of bound read, offset: " << offset << ", size: " << byte_count
+               << ", total package_size: " << package_size_;
+    return false;
+  }
+  memcpy(buffer, addr_ + offset, byte_count);
+  return true;
+}
+
+bool MemoryPackage::UpdateHashAtOffset(const std::vector<HasherUpdateCallback>& hashers,
+                                       uint64_t start, uint64_t length) {
+  if (length > package_size_ || start > package_size_ - length) {
+    LOG(ERROR) << "Out of bound read, offset: " << start << ", size: " << length
+               << ", total package_size: " << package_size_;
+    return false;
+  }
+
+  for (const auto& hasher : hashers) {
+    hasher(addr_ + start, length);
+  }
+  return true;
+}
+
+ZipArchiveHandle MemoryPackage::GetZipArchiveHandle() {
+  if (zip_handle_) {
+    return zip_handle_;
+  }
+
+  if (auto err = OpenArchiveFromMemory(const_cast<uint8_t*>(addr_), package_size_, path_.c_str(),
+                                       &zip_handle_);
+      err != 0) {
+    LOG(ERROR) << "Can't open package" << path_ << " : " << ErrorCodeString(err);
+    return nullptr;
+  }
+
+  return zip_handle_;
+}
+
+FilePackage::FilePackage(android::base::unique_fd&& fd, uint64_t file_size, const std::string& path,
+                         const std::function<void(float)>& set_progress)
+    : fd_(std::move(fd)), package_size_(file_size), path_(path), zip_handle_(nullptr) {
+  set_progress_ = set_progress;
+}
+
+FilePackage::~FilePackage() {
+  if (zip_handle_) {
+    CloseArchive(zip_handle_);
+  }
+}
+
+bool FilePackage::ReadFullyAtOffset(uint8_t* buffer, uint64_t byte_count, uint64_t offset) {
+  if (byte_count > package_size_ || offset > package_size_ - byte_count) {
+    LOG(ERROR) << "Out of bound read, offset: " << offset << ", size: " << byte_count
+               << ", total package_size: " << package_size_;
+    return false;
+  }
+
+  if (!android::base::ReadFullyAtOffset(fd_.get(), buffer, byte_count, offset)) {
+    PLOG(ERROR) << "Failed to read " << byte_count << " bytes data at offset " << offset;
+    return false;
+  }
+
+  return true;
+}
+
+bool FilePackage::UpdateHashAtOffset(const std::vector<HasherUpdateCallback>& hashers,
+                                     uint64_t start, uint64_t length) {
+  if (length > package_size_ || start > package_size_ - length) {
+    LOG(ERROR) << "Out of bound read, offset: " << start << ", size: " << length
+               << ", total package_size: " << package_size_;
+    return false;
+  }
+
+  uint64_t so_far = 0;
+  while (so_far < length) {
+    uint64_t read_size = std::min<uint64_t>(length - so_far, 16 * MiB);
+    std::vector<uint8_t> buffer(read_size);
+    if (!ReadFullyAtOffset(buffer.data(), read_size, start + so_far)) {
+      return false;
+    }
+
+    for (const auto& hasher : hashers) {
+      hasher(buffer.data(), read_size);
+    }
+    so_far += read_size;
+  }
+
+  return true;
+}
+
+ZipArchiveHandle FilePackage::GetZipArchiveHandle() {
+  if (zip_handle_) {
+    return zip_handle_;
+  }
+
+  if (auto err = OpenArchiveFd(fd_.get(), path_.c_str(), &zip_handle_); err != 0) {
+    LOG(ERROR) << "Can't open package" << path_ << " : " << ErrorCodeString(err);
+    return nullptr;
+  }
+
+  return zip_handle_;
+}
diff --git a/install/verifier.cpp b/install/verifier.cpp
new file mode 100644
index 000000000..6ba1d77c3
--- /dev/null
+++ b/install/verifier.cpp
@@ -0,0 +1,468 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+
+#include "install/verifier.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <algorithm>
+#include <functional>
+#include <memory>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <openssl/bio.h>
+#include <openssl/bn.h>
+#include <openssl/ecdsa.h>
+#include <openssl/evp.h>
+#include <openssl/obj_mac.h>
+#include <openssl/pem.h>
+#include <openssl/rsa.h>
+#include <ziparchive/zip_archive.h>
+
+#include "otautil/print_sha1.h"
+#include "private/asn1_decoder.h"
+
+/*
+ * Simple version of PKCS#7 SignedData extraction. This extracts the
+ * signature OCTET STRING to be used for signature verification.
+ *
+ * For full details, see http://www.ietf.org/rfc/rfc3852.txt
+ *
+ * The PKCS#7 structure looks like:
+ *
+ *   SEQUENCE (ContentInfo)
+ *     OID (ContentType)
+ *     [0] (content)
+ *       SEQUENCE (SignedData)
+ *         INTEGER (version CMSVersion)
+ *         SET (DigestAlgorithmIdentifiers)
+ *         SEQUENCE (EncapsulatedContentInfo)
+ *         [0] (CertificateSet OPTIONAL)
+ *         [1] (RevocationInfoChoices OPTIONAL)
+ *         SET (SignerInfos)
+ *           SEQUENCE (SignerInfo)
+ *             INTEGER (CMSVersion)
+ *             SEQUENCE (SignerIdentifier)
+ *             SEQUENCE (DigestAlgorithmIdentifier)
+ *             SEQUENCE (SignatureAlgorithmIdentifier)
+ *             OCTET STRING (SignatureValue)
+ */
+static bool read_pkcs7(const uint8_t* pkcs7_der, size_t pkcs7_der_len,
+                       std::vector<uint8_t>* sig_der) {
+  CHECK(sig_der != nullptr);
+  sig_der->clear();
+
+  asn1_context ctx(pkcs7_der, pkcs7_der_len);
+
+  std::unique_ptr<asn1_context> pkcs7_seq(ctx.asn1_sequence_get());
+  if (pkcs7_seq == nullptr || !pkcs7_seq->asn1_sequence_next()) {
+    return false;
+  }
+
+  std::unique_ptr<asn1_context> signed_data_app(pkcs7_seq->asn1_constructed_get());
+  if (signed_data_app == nullptr) {
+    return false;
+  }
+
+  std::unique_ptr<asn1_context> signed_data_seq(signed_data_app->asn1_sequence_get());
+  if (signed_data_seq == nullptr || !signed_data_seq->asn1_sequence_next() ||
+      !signed_data_seq->asn1_sequence_next() || !signed_data_seq->asn1_sequence_next() ||
+      !signed_data_seq->asn1_constructed_skip_all()) {
+    return false;
+  }
+
+  std::unique_ptr<asn1_context> sig_set(signed_data_seq->asn1_set_get());
+  if (sig_set == nullptr) {
+    return false;
+  }
+
+  std::unique_ptr<asn1_context> sig_seq(sig_set->asn1_sequence_get());
+  if (sig_seq == nullptr || !sig_seq->asn1_sequence_next() || !sig_seq->asn1_sequence_next() ||
+      !sig_seq->asn1_sequence_next() || !sig_seq->asn1_sequence_next()) {
+    return false;
+  }
+
+  const uint8_t* sig_der_ptr;
+  size_t sig_der_length;
+  if (!sig_seq->asn1_octet_string_get(&sig_der_ptr, &sig_der_length)) {
+    return false;
+  }
+
+  sig_der->resize(sig_der_length);
+  std::copy(sig_der_ptr, sig_der_ptr + sig_der_length, sig_der->begin());
+  return true;
+}
+
+int verify_file(VerifierInterface* package, const std::vector<Certificate>& keys) {
+  CHECK(package);
+  package->SetProgress(0.0);
+
+  // An archive with a whole-file signature will end in six bytes:
+  //
+  //   (2-byte signature start) $ff $ff (2-byte comment size)
+  //
+  // (As far as the ZIP format is concerned, these are part of the archive comment.) We start by
+  // reading this footer, this tells us how far back from the end we have to start reading to find
+  // the whole comment.
+
+#define FOOTER_SIZE 6
+  uint64_t length = package->GetPackageSize();
+
+  if (length < FOOTER_SIZE) {
+    LOG(ERROR) << "not big enough to contain footer";
+    return VERIFY_FAILURE;
+  }
+
+  uint8_t footer[FOOTER_SIZE];
+  if (!package->ReadFullyAtOffset(footer, FOOTER_SIZE, length - FOOTER_SIZE)) {
+    LOG(ERROR) << "Failed to read footer";
+    return VERIFY_FAILURE;
+  }
+
+  if (footer[2] != 0xff || footer[3] != 0xff) {
+    LOG(ERROR) << "footer is wrong";
+    return VERIFY_FAILURE;
+  }
+
+  size_t comment_size = footer[4] + (footer[5] << 8);
+  size_t signature_start = footer[0] + (footer[1] << 8);
+  LOG(INFO) << "comment is " << comment_size << " bytes; signature is " << signature_start
+            << " bytes from end";
+
+  if (signature_start > comment_size) {
+    LOG(ERROR) << "signature start: " << signature_start
+               << " is larger than comment size: " << comment_size;
+    return VERIFY_FAILURE;
+  }
+
+  if (signature_start <= FOOTER_SIZE) {
+    LOG(ERROR) << "Signature start is in the footer";
+    return VERIFY_FAILURE;
+  }
+
+#define EOCD_HEADER_SIZE 22
+
+  // The end-of-central-directory record is 22 bytes plus any comment length.
+  size_t eocd_size = comment_size + EOCD_HEADER_SIZE;
+
+  if (length < eocd_size) {
+    LOG(ERROR) << "not big enough to contain EOCD";
+    return VERIFY_FAILURE;
+  }
+
+  // Determine how much of the file is covered by the signature. This is everything except the
+  // signature data and length, which includes all of the EOCD except for the comment length field
+  // (2 bytes) and the comment data.
+  uint64_t signed_len = length - eocd_size + EOCD_HEADER_SIZE - 2;
+
+  uint8_t eocd[eocd_size];
+  if (!package->ReadFullyAtOffset(eocd, eocd_size, length - eocd_size)) {
+    LOG(ERROR) << "Failed to read EOCD of " << eocd_size << " bytes";
+    return VERIFY_FAILURE;
+  }
+
+  // If this is really is the EOCD record, it will begin with the magic number $50 $4b $05 $06.
+  if (eocd[0] != 0x50 || eocd[1] != 0x4b || eocd[2] != 0x05 || eocd[3] != 0x06) {
+    LOG(ERROR) << "signature length doesn't match EOCD marker";
+    return VERIFY_FAILURE;
+  }
+
+  for (size_t i = 4; i < eocd_size - 3; ++i) {
+    if (eocd[i] == 0x50 && eocd[i + 1] == 0x4b && eocd[i + 2] == 0x05 && eocd[i + 3] == 0x06) {
+      // If the sequence $50 $4b $05 $06 appears anywhere after the real one, libziparchive will
+      // find the later (wrong) one, which could be exploitable. Fail the verification if this
+      // sequence occurs anywhere after the real one.
+      LOG(ERROR) << "EOCD marker occurs after start of EOCD";
+      return VERIFY_FAILURE;
+    }
+  }
+
+  bool need_sha1 = false;
+  bool need_sha256 = false;
+  for (const auto& key : keys) {
+    switch (key.hash_len) {
+      case SHA_DIGEST_LENGTH:
+        need_sha1 = true;
+        break;
+      case SHA256_DIGEST_LENGTH:
+        need_sha256 = true;
+        break;
+    }
+  }
+
+  SHA_CTX sha1_ctx;
+  SHA256_CTX sha256_ctx;
+  SHA1_Init(&sha1_ctx);
+  SHA256_Init(&sha256_ctx);
+
+  std::vector<HasherUpdateCallback> hashers;
+  if (need_sha1) {
+    hashers.emplace_back(
+        std::bind(&SHA1_Update, &sha1_ctx, std::placeholders::_1, std::placeholders::_2));
+  }
+  if (need_sha256) {
+    hashers.emplace_back(
+        std::bind(&SHA256_Update, &sha256_ctx, std::placeholders::_1, std::placeholders::_2));
+  }
+
+  double frac = -1.0;
+  uint64_t so_far = 0;
+  while (so_far < signed_len) {
+    // On a Nexus 5X, experiment showed 16MiB beat 1MiB by 6% faster for a 1196MiB full OTA and
+    // 60% for an 89MiB incremental OTA. http://b/28135231.
+    uint64_t read_size = std::min<uint64_t>(signed_len - so_far, 16 * MiB);
+    package->UpdateHashAtOffset(hashers, so_far, read_size);
+    so_far += read_size;
+
+    double f = so_far / static_cast<double>(signed_len);
+    if (f > frac + 0.02 || read_size == so_far) {
+      package->SetProgress(f);
+      frac = f;
+    }
+  }
+
+  uint8_t sha1[SHA_DIGEST_LENGTH];
+  SHA1_Final(sha1, &sha1_ctx);
+  uint8_t sha256[SHA256_DIGEST_LENGTH];
+  SHA256_Final(sha256, &sha256_ctx);
+
+  const uint8_t* signature = eocd + eocd_size - signature_start;
+  size_t signature_size = signature_start - FOOTER_SIZE;
+
+  LOG(INFO) << "signature (offset: " << std::hex << (length - signature_start)
+            << ", length: " << signature_size << "): " << print_hex(signature, signature_size);
+
+  std::vector<uint8_t> sig_der;
+  if (!read_pkcs7(signature, signature_size, &sig_der)) {
+    LOG(ERROR) << "Could not find signature DER block";
+    return VERIFY_FAILURE;
+  }
+
+  // Check to make sure at least one of the keys matches the signature. Since any key can match,
+  // we need to try each before determining a verification failure has happened.
+  size_t i = 0;
+  for (const auto& key : keys) {
+    const uint8_t* hash;
+    int hash_nid;
+    switch (key.hash_len) {
+      case SHA_DIGEST_LENGTH:
+        hash = sha1;
+        hash_nid = NID_sha1;
+        break;
+      case SHA256_DIGEST_LENGTH:
+        hash = sha256;
+        hash_nid = NID_sha256;
+        break;
+      default:
+        continue;
+    }
+
+    // The 6 bytes is the "(signature_start) $ff $ff (comment_size)" that the signing tool appends
+    // after the signature itself.
+    if (key.key_type == Certificate::KEY_TYPE_RSA) {
+      if (!RSA_verify(hash_nid, hash, key.hash_len, sig_der.data(), sig_der.size(),
+                      key.rsa.get())) {
+        LOG(INFO) << "failed to verify against RSA key " << i;
+        continue;
+      }
+
+      LOG(INFO) << "whole-file signature verified against RSA key " << i;
+      return VERIFY_SUCCESS;
+    } else if (key.key_type == Certificate::KEY_TYPE_EC && key.hash_len == SHA256_DIGEST_LENGTH) {
+      if (!ECDSA_verify(0, hash, key.hash_len, sig_der.data(), sig_der.size(), key.ec.get())) {
+        LOG(INFO) << "failed to verify against EC key " << i;
+        continue;
+      }
+
+      LOG(INFO) << "whole-file signature verified against EC key " << i;
+      return VERIFY_SUCCESS;
+    } else {
+      LOG(INFO) << "Unknown key type " << key.key_type;
+    }
+    i++;
+  }
+
+  if (need_sha1) {
+    LOG(INFO) << "SHA-1 digest: " << print_hex(sha1, SHA_DIGEST_LENGTH);
+  }
+  if (need_sha256) {
+    LOG(INFO) << "SHA-256 digest: " << print_hex(sha256, SHA256_DIGEST_LENGTH);
+  }
+  LOG(ERROR) << "failed to verify whole-file signature";
+  return VERIFY_FAILURE;
+}
+
+static std::vector<Certificate> IterateZipEntriesAndSearchForKeys(const ZipArchiveHandle& handle) {
+  void* cookie;
+  ZipString suffix("x509.pem");
+  int32_t iter_status = StartIteration(handle, &cookie, nullptr, &suffix);
+  if (iter_status != 0) {
+    LOG(ERROR) << "Failed to iterate over entries in the certificate zipfile: "
+               << ErrorCodeString(iter_status);
+    return {};
+  }
+
+  std::vector<Certificate> result;
+
+  ZipString name;
+  ZipEntry entry;
+  while ((iter_status = Next(cookie, &entry, &name)) == 0) {
+    std::vector<uint8_t> pem_content(entry.uncompressed_length);
+    if (int32_t extract_status =
+            ExtractToMemory(handle, &entry, pem_content.data(), pem_content.size());
+        extract_status != 0) {
+      LOG(ERROR) << "Failed to extract " << std::string(name.name, name.name + name.name_length);
+      return {};
+    }
+
+    Certificate cert(0, Certificate::KEY_TYPE_RSA, nullptr, nullptr);
+    // Aborts the parsing if we fail to load one of the key file.
+    if (!LoadCertificateFromBuffer(pem_content, &cert)) {
+      LOG(ERROR) << "Failed to load keys from "
+                 << std::string(name.name, name.name + name.name_length);
+      return {};
+    }
+
+    result.emplace_back(std::move(cert));
+  }
+
+  if (iter_status != -1) {
+    LOG(ERROR) << "Error while iterating over zip entries: " << ErrorCodeString(iter_status);
+    return {};
+  }
+
+  return result;
+}
+
+std::vector<Certificate> LoadKeysFromZipfile(const std::string& zip_name) {
+  ZipArchiveHandle handle;
+  if (int32_t open_status = OpenArchive(zip_name.c_str(), &handle); open_status != 0) {
+    LOG(ERROR) << "Failed to open " << zip_name << ": " << ErrorCodeString(open_status);
+    return {};
+  }
+
+  std::vector<Certificate> result = IterateZipEntriesAndSearchForKeys(handle);
+  CloseArchive(handle);
+  return result;
+}
+
+bool CheckRSAKey(const std::unique_ptr<RSA, RSADeleter>& rsa) {
+  if (!rsa) {
+    return false;
+  }
+
+  const BIGNUM* out_n;
+  const BIGNUM* out_e;
+  RSA_get0_key(rsa.get(), &out_n, &out_e, nullptr /* private exponent */);
+  auto modulus_bits = BN_num_bits(out_n);
+  if (modulus_bits != 2048 && modulus_bits != 4096) {
+    LOG(ERROR) << "Modulus should be 2048 or 4096 bits long, actual: " << modulus_bits;
+    return false;
+  }
+
+  BN_ULONG exponent = BN_get_word(out_e);
+  if (exponent != 3 && exponent != 65537) {
+    LOG(ERROR) << "Public exponent should be 3 or 65537, actual: " << exponent;
+    return false;
+  }
+
+  return true;
+}
+
+bool CheckECKey(const std::unique_ptr<EC_KEY, ECKEYDeleter>& ec_key) {
+  if (!ec_key) {
+    return false;
+  }
+
+  const EC_GROUP* ec_group = EC_KEY_get0_group(ec_key.get());
+  if (!ec_group) {
+    LOG(ERROR) << "Failed to get the ec_group from the ec_key";
+    return false;
+  }
+  auto degree = EC_GROUP_get_degree(ec_group);
+  if (degree != 256) {
+    LOG(ERROR) << "Field size of the ec key should be 256 bits long, actual: " << degree;
+    return false;
+  }
+
+  return true;
+}
+
+bool LoadCertificateFromBuffer(const std::vector<uint8_t>& pem_content, Certificate* cert) {
+  std::unique_ptr<BIO, decltype(&BIO_free)> content(
+      BIO_new_mem_buf(pem_content.data(), pem_content.size()), BIO_free);
+
+  std::unique_ptr<X509, decltype(&X509_free)> x509(
+      PEM_read_bio_X509(content.get(), nullptr, nullptr, nullptr), X509_free);
+  if (!x509) {
+    LOG(ERROR) << "Failed to read x509 certificate";
+    return false;
+  }
+
+  int nid = X509_get_signature_nid(x509.get());
+  switch (nid) {
+    // SignApk has historically accepted md5WithRSA certificates, but treated them as
+    // sha1WithRSA anyway. Continue to do so for backwards compatibility.
+    case NID_md5WithRSA:
+    case NID_md5WithRSAEncryption:
+    case NID_sha1WithRSA:
+    case NID_sha1WithRSAEncryption:
+      cert->hash_len = SHA_DIGEST_LENGTH;
+      break;
+    case NID_sha256WithRSAEncryption:
+    case NID_ecdsa_with_SHA256:
+      cert->hash_len = SHA256_DIGEST_LENGTH;
+      break;
+    default:
+      LOG(ERROR) << "Unrecognized signature nid " << OBJ_nid2ln(nid);
+      return false;
+  }
+
+  std::unique_ptr<EVP_PKEY, decltype(&EVP_PKEY_free)> public_key(X509_get_pubkey(x509.get()),
+                                                                 EVP_PKEY_free);
+  if (!public_key) {
+    LOG(ERROR) << "Failed to extract the public key from x509 certificate";
+    return false;
+  }
+
+  int key_type = EVP_PKEY_id(public_key.get());
+  if (key_type == EVP_PKEY_RSA) {
+    cert->key_type = Certificate::KEY_TYPE_RSA;
+    cert->ec.reset();
+    cert->rsa.reset(EVP_PKEY_get1_RSA(public_key.get()));
+    if (!cert->rsa || !CheckRSAKey(cert->rsa)) {
+      LOG(ERROR) << "Failed to validate the rsa key info from public key";
+      return false;
+    }
+  } else if (key_type == EVP_PKEY_EC) {
+    cert->key_type = Certificate::KEY_TYPE_EC;
+    cert->rsa.reset();
+    cert->ec.reset(EVP_PKEY_get1_EC_KEY(public_key.get()));
+    if (!cert->ec || !CheckECKey(cert->ec)) {
+      LOG(ERROR) << "Failed to validate the ec key info from the public key";
+      return false;
+    }
+  } else {
+    LOG(ERROR) << "Unrecognized public key type " << OBJ_nid2ln(key_type);
+    return false;
+  }
+
+  return true;
+}