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Diffstat (limited to '')
| -rw-r--r-- | efs_migration.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/efs_migration.c b/efs_migration.c new file mode 100644 index 000000000..aeadd1865 --- /dev/null +++ b/efs_migration.c @@ -0,0 +1,183 @@ +/* + * 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; +} + |