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;
+}
+