| /* 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> |
| #define LOG_TAG "Cryptfs_HW" |
| #include "cutils/log.h" |
| #include "cutils/android_reboot.h" |
| |
| |
| // 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 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 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 int load_qseecom_library() |
| { |
| const char *error = NULL; |
| if (loaded_library) |
| return loaded_library; |
| |
| void * handle = dlopen("libQSEEComAPI.so", RTLD_NOW); |
| if(handle) { |
| dlerror(); /* Clear any existing error */ |
| *(void **) (&qseecom_create_key) = dlsym(handle,"QSEECom_create_key"); |
| |
| if((error = dlerror()) == NULL) { |
| *(void **) (&qseecom_update_key) = dlsym(handle,"QSEECom_update_key_user_info"); |
| if((error = dlerror()) == NULL) { |
| *(void **) (&qseecom_wipe_key) = dlsym(handle,"QSEECom_wipe_key"); |
| if ((error = dlerror()) == NULL) |
| loaded_library = 1; |
| else |
| SLOGE("Error %s loading symbols for QSEECom APIs", error); |
| } |
| } |
| } else { |
| SLOGE("Could not load libQSEEComAPI.so"); |
| } |
| |
| if(error) |
| dlclose(handle); |
| |
| return loaded_library; |
| } |
| |
| static unsigned int set_key(const char* passwd, const char* enc_mode, int operation) |
| { |
| int ret = 0; |
| 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(QSEECOM_DISK_ENCRYPTION, current_passwd, tmp_passwd); |
| else if (operation == SET_HW_DISK_ENC_KEY) |
| err = qseecom_create_key(QSEECOM_DISK_ENCRYPTION, tmp_passwd); |
| |
| if(!err) { |
| memset(current_passwd, 0, MAX_PASSWORD_LEN); |
| memcpy(current_passwd, tmp_passwd, MAX_PASSWORD_LEN); |
| ret = 1; |
| } else { |
| if(ERR_MAX_PASSWORD_ATTEMPTS == err) |
| SLOGE("Maximum password attempts reached. Need factory data reset to recover."); |
| } |
| free(tmp_passwd); |
| } |
| } |
| return ret; |
| } |
| |
| unsigned int set_hw_device_encryption_key(const char* passwd, const char* enc_mode) |
| { |
| SLOGI("Set key for HW disk encryption operation"); |
| 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) |
| { |
| SLOGI("Update key for HW disk encryption operation"); |
| 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")) { |
| ret = 1; |
| } |
| } |
| return ret; |
| } |
| |
| unsigned int clear_hw_device_encryption_key() |
| { |
| int err = -1; |
| int rc = 0; |
| SLOGI("Clear HW disk encryption key"); |
| if (load_qseecom_library()) { |
| err = qseecom_wipe_key(1); |
| } |
| |
| if (!err) rc = 1; |
| |
| return rc; |
| } |