Verify wipe package when wiping A/B device in recovery.
To increase the security of wiping A/B devices, let uncrypt write
wipe package in misc partition. Then recovery verifies the wipe
package before wiping the device.
Bug: 29159185
Change-Id: I186691bab1928d3dc036bc5542abd64a81bc2168
diff --git a/recovery.cpp b/recovery.cpp
index 65e1a7b..6df9b6f 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -61,6 +61,7 @@
#include "install.h"
#include "minui/minui.h"
#include "minzip/DirUtil.h"
+#include "minzip/Zip.h"
#include "roots.h"
#include "ui.h"
#include "unique_fd.h"
@@ -84,6 +85,7 @@
{ "reason", required_argument, NULL, 'r' },
{ "security", no_argument, NULL, 'e'},
{ "wipe_ab", no_argument, NULL, 0 },
+ { "wipe_package_size", required_argument, NULL, 0 },
{ NULL, 0, NULL, 0 },
};
@@ -904,12 +906,75 @@
return true;
}
+// Check if the wipe package matches expectation:
+// 1. verify the package.
+// 2. check metadata (ota-type, pre-device and serial number if having one).
+static bool check_wipe_package(size_t wipe_package_size) {
+ if (wipe_package_size == 0) {
+ LOGE("wipe_package_size is zero.\n");
+ return false;
+ }
+ std::string wipe_package;
+ if (!read_wipe_package(wipe_package_size, &wipe_package)) {
+ LOGE("Failed to read wipe package.\n");
+ return false;
+ }
+ if (!verify_package(reinterpret_cast<const unsigned char*>(wipe_package.data()),
+ wipe_package.size())) {
+ LOGE("Failed to verify package.\n");
+ return false;
+ }
+
+ // Extract metadata
+ ZipArchive zip;
+ int err = mzOpenZipArchive(reinterpret_cast<unsigned char*>(&wipe_package[0]),
+ wipe_package.size(), &zip);
+ if (err != 0) {
+ LOGE("Can't open wipe package: %s\n", err != -1 ? strerror(err) : "bad");
+ return false;
+ }
+ std::string metadata;
+ if (!read_metadata_from_package(&zip, &metadata)) {
+ mzCloseZipArchive(&zip);
+ return false;
+ }
+ mzCloseZipArchive(&zip);
+
+ // Check metadata
+ std::vector<std::string> lines = android::base::Split(metadata, "\n");
+ bool ota_type_matched = false;
+ bool device_type_matched = false;
+ bool has_serial_number = false;
+ bool serial_number_matched = false;
+ for (const auto& line : lines) {
+ if (line == "ota-type=BRICK") {
+ ota_type_matched = true;
+ } else if (android::base::StartsWith(line, "pre-device=")) {
+ std::string device_type = line.substr(strlen("pre-device="));
+ char real_device_type[PROPERTY_VALUE_MAX];
+ property_get("ro.build.product", real_device_type, "");
+ device_type_matched = (device_type == real_device_type);
+ } else if (android::base::StartsWith(line, "serialno=")) {
+ std::string serial_no = line.substr(strlen("serialno="));
+ char real_serial_no[PROPERTY_VALUE_MAX];
+ property_get("ro.serialno", real_serial_no, "");
+ has_serial_number = true;
+ serial_number_matched = (serial_no == real_serial_no);
+ }
+ }
+ return ota_type_matched && device_type_matched && (!has_serial_number || serial_number_matched);
+}
+
// Wipe the current A/B device, with a secure wipe of all the partitions in
// RECOVERY_WIPE.
-static bool wipe_ab_device() {
+static bool wipe_ab_device(size_t wipe_package_size) {
ui->SetBackground(RecoveryUI::ERASING);
ui->SetProgressType(RecoveryUI::INDETERMINATE);
+ if (!check_wipe_package(wipe_package_size)) {
+ LOGE("Failed to verify wipe package\n");
+ return false;
+ }
std::string partition_list;
if (!android::base::ReadFileToString(RECOVERY_WIPE, &partition_list)) {
LOGE("failed to read \"%s\".\n", RECOVERY_WIPE);
@@ -1418,6 +1483,7 @@
bool should_wipe_data = false;
bool should_wipe_cache = false;
bool should_wipe_ab = false;
+ size_t wipe_package_size = 0;
bool show_text = false;
bool sideload = false;
bool sideload_auto_reboot = false;
@@ -1455,6 +1521,9 @@
if (strcmp(OPTIONS[option_index].name, "wipe_ab") == 0) {
should_wipe_ab = true;
break;
+ } else if (strcmp(OPTIONS[option_index].name, "wipe_package_size") == 0) {
+ android::base::ParseUint(optarg, &wipe_package_size);
+ break;
}
break;
}
@@ -1597,7 +1666,7 @@
status = INSTALL_ERROR;
}
} else if (should_wipe_ab) {
- if (!wipe_ab_device()) {
+ if (!wipe_ab_device(wipe_package_size)) {
status = INSTALL_ERROR;
}
} else if (sideload) {