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/*
* Copyright (C) 2009 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "efs_migration.h"
#include "cutils/misc.h"
#include "cutils/properties.h"
#include "common.h"
#include "mtdutils/mtdutils.h"
#include "mtdutils/mounts.h"
#include "roots.h"
const char* efs_enabled_property = "persist.security.efs.enabled";
const char* efs_transition_property = "persist.security.efs.trans";
const char* efs_property_dir = "/data/property/";
void get_property_file_name(char *buffer, const char *property_name) {
sprintf(buffer, "%s%s", efs_property_dir, property_name);
}
int get_text_file_contents(char *buffer, int buf_size, char *file_name) {
FILE *in_file;
char *read_data;
in_file = fopen(file_name, "r");
if (in_file == NULL) {
LOGE("Encrypted FS: error accessing properties.");
return EFS_ERROR;
}
read_data = fgets(buffer, buf_size, in_file);
if (read_data == NULL) {
// Error or unexpected data
fclose(in_file);
LOGE("Encrypted FS: error accessing properties.");
return EFS_ERROR;
}
fclose(in_file);
return EFS_OK;
}
int set_text_file_contents(char *buffer, char *file_name) {
FILE *out_file;
int result;
out_file = fopen(file_name, "w");
if (out_file == NULL) {
LOGE("Encrypted FS: error setting up properties.");
return EFS_ERROR;
}
result = fputs(buffer, out_file);
if (result != 0) {
// Error or unexpected data
fclose(out_file);
LOGE("Encrypted FS: error setting up properties.");
return EFS_ERROR;
}
fflush(out_file);
fclose(out_file);
return EFS_OK;
}
int read_efs_boolean_property(const char *prop_name, int *value) {
char prop_file_name[PROPERTY_KEY_MAX + 32];
char prop_value[PROPERTY_VALUE_MAX];
int result;
get_property_file_name(prop_file_name, prop_name);
result = get_text_file_contents(prop_value, PROPERTY_VALUE_MAX, prop_file_name);
if (result < 0) {
return result;
}
if (strncmp(prop_value, "1", 1) == 0) {
*value = 1;
} else if (strncmp(prop_value, "0", 1) == 0) {
*value = 0;
} else {
LOGE("Encrypted FS: error accessing properties.");
return EFS_ERROR;
}
return EFS_OK;
}
int write_efs_boolean_property(const char *prop_name, int value) {
char prop_file_name[PROPERTY_KEY_MAX + 32];
char prop_value[PROPERTY_VALUE_MAX];
int result;
get_property_file_name(prop_file_name, prop_name);
// Create the directory if needed
mkdir(efs_property_dir, 0755);
if (value == 1) {
result = set_text_file_contents("1", prop_file_name);
} else if (value == 0) {
result = set_text_file_contents("0", prop_file_name);
} else {
return EFS_ERROR;
}
if (result < 0) {
return result;
}
return EFS_OK;
}
int read_encrypted_fs_info(encrypted_fs_info *efs_data) {
int result;
int value;
result = ensure_root_path_mounted("DATA:");
if (result != 0) {
LOGE("Encrypted FS: error mounting userdata partition.");
return EFS_ERROR;
}
// STOPSHIP: Read the EFS key from a file (TBD later)
// Future code goes here...
result = ensure_root_path_unmounted("DATA:");
if (result != 0) {
LOGE("Encrypted FS: error unmounting data partition.");
return EFS_ERROR;
}
return EFS_OK;
}
int restore_encrypted_fs_info(encrypted_fs_info *efs_data) {
int result;
result = ensure_root_path_mounted("DATA:");
if (result != 0) {
LOGE("Encrypted FS: error mounting userdata partition.");
return EFS_ERROR;
}
// Set the EFS properties to their respective values
result = write_efs_boolean_property(efs_enabled_property, efs_data->encrypted_fs_mode);
if (result != 0) {
return result;
}
// Signal "transition" of Encrypted File System settings
result = write_efs_boolean_property(efs_transition_property, 1);
if (result != 0) {
return result;
}
result = ensure_root_path_unmounted("DATA:");
if (result != 0) {
LOGE("Encrypted FS: error unmounting data partition.");
return EFS_ERROR;
}
return EFS_OK;
}
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