/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of The Linux Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <cryptfs_hw.h>
#include <stdlib.h>
#include <sys/limits.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <dlfcn.h>
#include "cutils/log.h"
#include "cutils/properties.h"
#include "cutils/android_reboot.h"
#if defined(__LP64__)
#define QSEECOM_LIBRARY_PATH "/vendor/lib64/libQSEEComAPI.so"
#else
#define QSEECOM_LIBRARY_PATH "/vendor/lib/libQSEEComAPI.so"
#endif
// When device comes up or when user tries to change the password, user can
// try wrong password upto a certain number of times. If user enters wrong
// password further, HW would wipe all disk encryption related crypto data
// and would return an error ERR_MAX_PASSWORD_ATTEMPTS to VOLD. VOLD would
// wipe userdata partition once this error is received.
#define ERR_MAX_PASSWORD_ATTEMPTS -10
#define QSEECOM_DISK_ENCRYPTION 1
#define QSEECOM_ICE_DISK_ENCRYPTION 3
#define MAX_PASSWORD_LEN 32
/* Operations that be performed on HW based device encryption key */
#define SET_HW_DISK_ENC_KEY 1
#define UPDATE_HW_DISK_ENC_KEY 2
static int loaded_library = 0;
static unsigned char current_passwd[MAX_PASSWORD_LEN];
static int (*qseecom_create_key)(int, void*);
static int (*qseecom_update_key)(int, void*, void*);
static int (*qseecom_wipe_key)(int);
static int map_usage(int usage)
{
return (is_ice_enabled() && (usage == QSEECOM_DISK_ENCRYPTION)) ?
QSEECOM_ICE_DISK_ENCRYPTION : usage;
}
static unsigned char* get_tmp_passwd(const char* passwd)
{
int passwd_len = 0;
unsigned char * tmp_passwd = NULL;
if(passwd) {
tmp_passwd = (unsigned char*)malloc(MAX_PASSWORD_LEN);
if(tmp_passwd) {
memset(tmp_passwd, 0, MAX_PASSWORD_LEN);
passwd_len = (strlen(passwd) > MAX_PASSWORD_LEN) ? MAX_PASSWORD_LEN : strlen(passwd);
memcpy(tmp_passwd, passwd, passwd_len);
} else {
SLOGE("%s: Failed to allocate memory for tmp passwd \n", __func__);
}
} else {
SLOGE("%s: Passed argument is NULL \n", __func__);
}
return tmp_passwd;
}
static void wipe_userdata()
{
mkdir("/cache/recovery", 0700);
int fd = open("/cache/recovery/command", O_RDWR|O_CREAT|O_TRUNC|O_NOFOLLOW, 0600);
if (fd >= 0) {
write(fd, "--wipe_data", strlen("--wipe_data") + 1);
close(fd);
} else {
SLOGE("could not open /cache/recovery/command\n");
}
android_reboot(ANDROID_RB_RESTART2, 0, "recovery");
}
static int load_qseecom_library()
{
const char *error = NULL;
if (loaded_library)
return loaded_library;
void * handle = dlopen(QSEECOM_LIBRARY_PATH, RTLD_NOW);
if(handle) {
dlerror(); /* Clear any existing error */
*(void **) (&qseecom_create_key) = dlsym(handle,"QSEECom_create_key");
if((error = dlerror()) == NULL) {
SLOGD("Success loading QSEECom_create_key \n");
*(void **) (&qseecom_update_key) = dlsym(handle,"QSEECom_update_key_user_info");
if ((error = dlerror()) == NULL) {
SLOGD("Success loading QSEECom_update_key_user_info\n");
*(void **) (&qseecom_wipe_key) = dlsym(handle,"QSEECom_wipe_key");
if ((error = dlerror()) == NULL) {
loaded_library = 1;
SLOGD("Success loading QSEECom_wipe_key \n");
}
else
SLOGE("Error %s loading symbols for QSEECom APIs \n", error);
}
else
SLOGE("Error %s loading symbols for QSEECom APIs \n", error);
}
} else {
SLOGE("Could not load libQSEEComAPI.so \n");
}
if(error)
dlclose(handle);
return loaded_library;
}
/*
* For NON-ICE targets, it would return 0 on success. On ICE based targets,
* it would return key index in the ICE Key LUT
*/
static int set_key(const char* passwd, const char* enc_mode, int operation)
{
int err = -1;
if (is_hw_disk_encryption(enc_mode) && load_qseecom_library()) {
unsigned char* tmp_passwd = get_tmp_passwd(passwd);
if(tmp_passwd) {
if (operation == UPDATE_HW_DISK_ENC_KEY)
err = qseecom_update_key(map_usage(QSEECOM_DISK_ENCRYPTION), current_passwd, tmp_passwd);
else if (operation == SET_HW_DISK_ENC_KEY)
err = qseecom_create_key(map_usage(QSEECOM_DISK_ENCRYPTION), tmp_passwd);
if(err >= 0) {
memset(current_passwd, 0, MAX_PASSWORD_LEN);
memcpy(current_passwd, tmp_passwd, MAX_PASSWORD_LEN);
} else {
if(ERR_MAX_PASSWORD_ATTEMPTS == err)
wipe_userdata();
}
free(tmp_passwd);
}
}
return err;
}
unsigned int set_hw_device_encryption_key(const char* passwd, const char* enc_mode)
{
return set_key(passwd, enc_mode, SET_HW_DISK_ENC_KEY);
}
unsigned int update_hw_device_encryption_key(const char* newpw, const char* enc_mode)
{
return set_key(newpw, enc_mode, UPDATE_HW_DISK_ENC_KEY);
}
unsigned int is_hw_disk_encryption(const char* encryption_mode)
{
int ret = 0;
if(encryption_mode) {
if (!strcmp(encryption_mode, "aes-xts")) {
SLOGD("HW based disk encryption is enabled \n");
ret = 1;
}
}
return ret;
}
unsigned int wipe_hw_device_encryption_key(const char* enc_mode)
{
if (!enc_mode)
return -1;
if (is_hw_disk_encryption(enc_mode) && load_qseecom_library())
return qseecom_wipe_key(QSEECOM_DISK_ENCRYPTION);
return 0;
}
int is_ice_enabled(void)
{
/* If (USE_ICE_FLAG) => return 1
* if (property set to use gpce) return 0
* we are using property to test UFS + GPCE, even though not required
* if (storage is ufs) return 1
* else return 0 so that emmc based device can work properly
*/
#ifdef USE_ICE_FOR_STORAGE_ENCRYPTION
SLOGD("Ice enabled = true");
return 1;
#else
char enc_hw_type[PATH_MAX];
char prop_storage[PATH_MAX];
int ice = 0;
int i;
if (property_get("crypto.fde_enc_hw_type", enc_hw_type, "")) {
if(!strncmp(enc_hw_type, "gpce", PROPERTY_VALUE_MAX)) {
SLOGD("GPCE would be used for HW FDE");
return 0;
}
}
if (property_get("ro.boot.bootdevice", prop_storage, "")) {
if(strstr(prop_storage, "ufs")) {
