PawletOS/android_bootable_recovery
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Verify wipe package when wiping A/B device in recovery.

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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
This commit is contained in:
Yabin Cui
2016-06-20 18:18:02 -07:00
parent dc1393d09b
commit 6faf0265c9
8 changed files with 231 additions and 76 deletions
Download Patch File Download Diff File Expand all files Collapse all files
bootloader.cpp
+58 -41
View File
@@ -25,6 +25,8 @@
#include <fs_mgr.h>
#include <android-base/file.h>
#include "bootloader.h"
#include "common.h"
#include "mtdutils/mtdutils.h"
@@ -33,8 +35,8 @@
static int get_bootloader_message_mtd(bootloader_message* out, const Volume* v);
static int set_bootloader_message_mtd(const bootloader_message* in, const Volume* v);
static int get_bootloader_message_block(bootloader_message* out, const Volume* v);
static int set_bootloader_message_block(const bootloader_message* in, const Volume* v);
static bool read_misc_partition(const Volume* v, size_t offset, size_t size, std::string* out);
static bool write_misc_partition(const Volume* v, size_t offset, const std::string& in);
int get_bootloader_message(bootloader_message* out) {
Volume* v = volume_for_path("/misc");
@@ -45,12 +47,34 @@ int get_bootloader_message(bootloader_message* out) {
if (strcmp(v->fs_type, "mtd") == 0) {
return get_bootloader_message_mtd(out, v);
} else if (strcmp(v->fs_type, "emmc") == 0) {
return get_bootloader_message_block(out, v);
std::string s;
if (!read_misc_partition(v, BOOTLOADER_MESSAGE_OFFSET_IN_MISC, sizeof(bootloader_message),
&s)) {
return -1;
}
memcpy(out, s.data(), s.size());
return 0;
}
LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
LOGE("Unknown misc partition fs_type \"%s\"\n", v->fs_type);
return -1;
}
bool read_wipe_package(size_t size, std::string* out) {
Volume* v = volume_for_path("/misc");
if (v == nullptr) {
LOGE("Cannot load volume /misc!\n");
return false;
}
if (strcmp(v->fs_type, "mtd") == 0) {
LOGE("Read wipe package on mtd is not supported.\n");
return false;
} else if (strcmp(v->fs_type, "emmc") == 0) {
return read_misc_partition(v, WIPE_PACKAGE_OFFSET_IN_MISC, size, out);
}
LOGE("Unknown misc partition fs_type \"%s\"\n", v->fs_type);
return false;
}
int set_bootloader_message(const bootloader_message* in) {
Volume* v = volume_for_path("/misc");
if (v == nullptr) {
@@ -60,9 +84,11 @@ int set_bootloader_message(const bootloader_message* in) {
if (strcmp(v->fs_type, "mtd") == 0) {
return set_bootloader_message_mtd(in, v);
} else if (strcmp(v->fs_type, "emmc") == 0) {
return set_bootloader_message_block(in, v);
std::string s(reinterpret_cast<const char*>(in), sizeof(*in));
bool success = write_misc_partition(v, BOOTLOADER_MESSAGE_OFFSET_IN_MISC, s);
return success ? 0 : -1;
}
LOGE("unknown misc partition fs_type \"%s\"\n", v->fs_type);
LOGE("Unknown misc partition fs_type \"%s\"\n", v->fs_type);
return -1;
}
@@ -166,53 +192,44 @@ static void wait_for_device(const char* fn) {
}
}
static int get_bootloader_message_block(bootloader_message* out,
const Volume* v) {
static bool read_misc_partition(const Volume* v, size_t offset, size_t size, std::string* out) {
wait_for_device(v->blk_device);
FILE* f = fopen(v->blk_device, "rb");
if (f == nullptr) {
LOGE("failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
return -1;
unique_fd fd(open(v->blk_device, O_RDONLY));
if (fd.get() == -1) {
LOGE("Failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
return false;
}
bootloader_message temp;
int count = fread(&temp, sizeof(temp), 1, f);
if (count != 1) {
LOGE("failed to read \"%s\": %s\n", v->blk_device, strerror(errno));
return -1;
if (lseek(fd.get(), static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) {
LOGE("Failed to lseek \"%s\": %s\n", v->blk_device, strerror(errno));
return false;
}
if (fclose(f) != 0) {
LOGE("failed to close \"%s\": %s\n", v->blk_device, strerror(errno));
return -1;
out->resize(size);
if (!android::base::ReadFully(fd.get(), &(*out)[0], size)) {
LOGE("Failed to read \"%s\": %s\n", v->blk_device, strerror(errno));
return false;
}
memcpy(out, &temp, sizeof(temp));
return 0;
return true;
}
static int set_bootloader_message_block(const bootloader_message* in,
const Volume* v) {
static bool write_misc_partition(const Volume* v, size_t offset, const std::string& in) {
wait_for_device(v->blk_device);
unique_fd fd(open(v->blk_device, O_WRONLY | O_SYNC));
if (fd.get() == -1) {
LOGE("failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
return -1;
LOGE("Failed to open \"%s\": %s\n", v->blk_device, strerror(errno));
return false;
}
size_t written = 0;
const uint8_t* start = reinterpret_cast<const uint8_t*>(in);
size_t total = sizeof(*in);
while (written < total) {
ssize_t wrote = TEMP_FAILURE_RETRY(write(fd.get(), start + written, total - written));
if (wrote == -1) {
LOGE("failed to write %" PRId64 " bytes: %s\n",
static_cast<off64_t>(written), strerror(errno));
return -1;
}
written += wrote;
if (lseek(fd.get(), static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) {
LOGE("Failed to lseek \"%s\": %s\n", v->blk_device, strerror(errno));
return false;
}
if (!android::base::WriteFully(fd.get(), in.data(), in.size())) {
LOGE("Failed to write \"%s\": %s\n", v->blk_device, strerror(errno));
return false;
}
if (fsync(fd.get()) == -1) {
LOGE("failed to fsync \"%s\": %s\n", v->blk_device, strerror(errno));
return -1;
LOGE("Failed to fsync \"%s\": %s\n", v->blk_device, strerror(errno));
return false;
}
return 0;
return true;
}