2 * Copyright (C) 2016 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include "ext4_utils/ext4_crypt_init_extensions.h"
21 #include <sys/mount.h>
28 #include <android-base/file.h>
29 #include <android-base/logging.h>
30 #include <android-base/stringprintf.h>
31 #include <android-base/strings.h>
32 #include <cutils/properties.h>
33 #include <cutils/sockets.h>
34 #include <logwrap/logwrap.h>
36 #include "ext4_utils/ext4_crypt.h"
37 #include "ext4_utils/key_control.h"
39 #define TAG "ext4_utils"
41 static const std::string arbitrary_sequence_number = "42";
42 static const int vold_command_timeout_ms = 60 * 1000;
44 int e4crypt_create_device_key(const char* dir,
45 int ensure_dir_exists(const char*))
47 // Make sure folder exists. Use make_dir to set selinux permissions.
48 std::string unencrypted_dir = std::string(dir) + e4crypt_unencrypted_folder;
49 if (ensure_dir_exists(unencrypted_dir.c_str())) {
50 PLOG(ERROR) << "Failed to create " << unencrypted_dir;
54 const char* argv[] = { "/system/bin/vdc", "--wait", "cryptfs", "enablefilecrypto" };
55 int rc = android_fork_execvp_ext(arraysize(argv), (char**) argv, NULL, false,
56 LOG_KLOG, false, NULL, NULL, 0);
57 LOG(INFO) << "enablefilecrypto result: " << rc;
61 int e4crypt_install_keyring()
63 key_serial_t device_keyring = add_key("keyring", "e4crypt", 0, 0,
64 KEY_SPEC_SESSION_KEYRING);
66 if (device_keyring == -1) {
67 PLOG(ERROR) << "Failed to create keyring";
71 LOG(INFO) << "Keyring created with id " << device_keyring << " in process " << getpid();
76 int e4crypt_do_init_user0()
78 const char* argv[] = { "/system/bin/vdc", "--wait", "cryptfs", "init_user0" };
79 int rc = android_fork_execvp_ext(arraysize(argv), (char**) argv, NULL, false,
80 LOG_KLOG, false, NULL, NULL, 0);
81 LOG(INFO) << "init_user0 result: " << rc;
85 int e4crypt_set_directory_policy(const char* dir)
87 // Only set policy on first level /data directories
88 // To make this less restrictive, consider using a policy file.
89 // However this is overkill for as long as the policy is simply
90 // to apply a global policy to all /data folders created via makedir
91 if (!dir || strncmp(dir, "/data/", 6) || strchr(dir + 6, '/')) {
95 // Special case various directories that must not be encrypted,
96 // often because their subdirectories must be encrypted.
97 // This isn't a nice way to do this, see b/26641735
98 std::vector<std::string> directories_to_exclude = {
100 "system_ce", "system_de",
101 "misc_ce", "misc_de",
103 "data", "user", "user_de",
105 std::string prefix = "/data/";
106 for (auto d: directories_to_exclude) {
107 if ((prefix + d) == dir) {
108 LOG(INFO) << "Not setting policy on " << dir;
113 std::string ref_filename = std::string("/data") + e4crypt_key_ref;
115 if (!android::base::ReadFileToString(ref_filename, &policy)) {
116 LOG(ERROR) << "Unable to read system policy to set on " << dir;
120 auto type_filename = std::string("/data") + e4crypt_key_mode;
121 std::string modestring;
122 if (!android::base::ReadFileToString(type_filename, &modestring)) {
123 LOG(ERROR) << "Cannot read mode";
126 std::vector<std::string> modes = android::base::Split(modestring, ":");
128 if (modes.size() < 1 || modes.size() > 2) {
129 LOG(ERROR) << "Invalid encryption mode string: " << modestring;
133 LOG(INFO) << "Setting policy on " << dir;
134 int result = e4crypt_policy_ensure(dir, policy.c_str(), policy.length(),
137 modes[1].c_str() : "aes-256-cts");
139 LOG(ERROR) << android::base::StringPrintf(
140 "Setting %02x%02x%02x%02x policy on %s failed!",
141 policy[0], policy[1], policy[2], policy[3], dir);