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Jeff Sharkeyd2c96e72015-11-08 17:56:23 -08001/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
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
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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.
15 */
16
Paul Lawrence731a7a22015-04-28 22:14:15 +000017#include "Ext4Crypt.h"
18
Paul Crowley1ef25582016-01-21 20:26:12 +000019#include "KeyStorage.h"
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -080020#include "Utils.h"
21
Paul Lawrencefd7db732015-04-10 07:48:51 -070022#include <iomanip>
Paul Lawrence731a7a22015-04-28 22:14:15 +000023#include <map>
Paul Crowleyb1f3d242016-01-28 10:09:46 +000024#include <set>
Paul Lawrencefd7db732015-04-10 07:48:51 -070025#include <string>
26#include <sstream>
Paul Lawrence731a7a22015-04-28 22:14:15 +000027
Paul Crowleyb1f3d242016-01-28 10:09:46 +000028#include <stdio.h>
Paul Lawrence731a7a22015-04-28 22:14:15 +000029#include <errno.h>
Paul Crowley95376d62015-05-06 15:04:43 +010030#include <dirent.h>
Paul Lawrence731a7a22015-04-28 22:14:15 +000031#include <sys/mount.h>
Paul Crowley95376d62015-05-06 15:04:43 +010032#include <sys/types.h>
33#include <sys/stat.h>
34#include <fcntl.h>
Paul Lawrence731a7a22015-04-28 22:14:15 +000035#include <cutils/properties.h>
Paul Lawrencefd7db732015-04-10 07:48:51 -070036#include <openssl/sha.h>
Jeff Sharkey7a9dd952016-01-12 16:52:16 -070037#include <selinux/android.h>
Paul Lawrence731a7a22015-04-28 22:14:15 +000038
Paul Crowley480fcd22015-08-24 14:53:28 +010039#include <private/android_filesystem_config.h>
40
Paul Lawrence731a7a22015-04-28 22:14:15 +000041#include "unencrypted_properties.h"
42#include "key_control.h"
43#include "cryptfs.h"
Paul Crowley95376d62015-05-06 15:04:43 +010044#include "ext4_crypt_init_extensions.h"
Paul Lawrence731a7a22015-04-28 22:14:15 +000045
46#define LOG_TAG "Ext4Crypt"
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -080047
Jeff Sharkey7a9dd952016-01-12 16:52:16 -070048#define EMULATED_USES_SELINUX 0
49
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -080050#include <cutils/fs.h>
51#include <cutils/log.h>
Paul Lawrence731a7a22015-04-28 22:14:15 +000052#include <cutils/klog.h>
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -080053
Elliott Hughes7e128fb2015-12-04 15:50:53 -080054#include <android-base/file.h>
Elliott Hughes6bf05472015-12-04 17:55:33 -080055#include <android-base/logging.h>
Elliott Hughes7e128fb2015-12-04 15:50:53 -080056#include <android-base/stringprintf.h>
Paul Lawrence731a7a22015-04-28 22:14:15 +000057
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -080058using android::base::StringPrintf;
59
Jeff Sharkeyfc505c32015-12-07 17:27:01 -070060static bool e4crypt_is_native() {
61 char value[PROPERTY_VALUE_MAX];
62 property_get("ro.crypto.type", value, "none");
63 return !strcmp(value, "file");
64}
65
66static bool e4crypt_is_emulated() {
67 return property_get_bool("persist.sys.emulate_fbe", false);
68}
Jeff Sharkeyc79fb892015-11-12 20:18:02 -080069
Paul Lawrence731a7a22015-04-28 22:14:15 +000070namespace {
71 // Key length in bits
72 const int key_length = 128;
Paul Lawrencefd7db732015-04-10 07:48:51 -070073 static_assert(key_length % 8 == 0,
74 "Key length must be multiple of 8 bits");
Paul Lawrence731a7a22015-04-28 22:14:15 +000075
Paul Lawrence5a06a642016-02-03 13:39:13 -080076 const std::string device_key_leaf = "/unencrypted/key";
77 const std::string device_key_temp = "/unencrypted/temp";
78
Paul Crowley285956f2016-01-20 13:12:38 +000079 const std::string user_key_dir = std::string() + DATA_MNT_POINT + "/misc/vold/user_keys";
Paul Crowleyb1f3d242016-01-28 10:09:46 +000080 const std::string user_key_temp = user_key_dir + "/temp";
Paul Crowley285956f2016-01-20 13:12:38 +000081
Paul Lawrence7b6b5652016-02-02 11:14:59 -080082 bool s_enabled = false;
83
Paul Crowleyb1f3d242016-01-28 10:09:46 +000084 // Some users are ephemeral, don't try to wipe their keys from disk
85 std::set<userid_t> s_ephemeral_users;
Paul Lawrenceaec34df2016-02-03 10:52:41 -080086
Paul Crowleyb1f3d242016-01-28 10:09:46 +000087 // Map user ids to key references
Paul Crowleyb92f83c2016-02-01 14:10:43 +000088 std::map<userid_t, std::string> s_de_key_raw_refs;
Paul Crowleyb1f3d242016-01-28 10:09:46 +000089 std::map<userid_t, std::string> s_ce_key_raw_refs;
Paul Lawrence731a7a22015-04-28 22:14:15 +000090
Paul Crowley285956f2016-01-20 13:12:38 +000091 // ext4enc:TODO get this const from somewhere good
Paul Lawrencefd7db732015-04-10 07:48:51 -070092 const int EXT4_KEY_DESCRIPTOR_SIZE = 8;
93
Paul Lawrence731a7a22015-04-28 22:14:15 +000094 // ext4enc:TODO Include structure from somewhere sensible
95 // MUST be in sync with ext4_crypto.c in kernel
Paul Lawrencefd7db732015-04-10 07:48:51 -070096 const int EXT4_MAX_KEY_SIZE = 64;
97 const int EXT4_ENCRYPTION_MODE_AES_256_XTS = 1;
Paul Lawrence731a7a22015-04-28 22:14:15 +000098 struct ext4_encryption_key {
Paul Lawrencefd7db732015-04-10 07:48:51 -070099 uint32_t mode;
100 char raw[EXT4_MAX_KEY_SIZE];
101 uint32_t size;
Paul Lawrence731a7a22015-04-28 22:14:15 +0000102 };
Paul Lawrence731a7a22015-04-28 22:14:15 +0000103}
104
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000105static bool install_key(const std::string &key, std::string &raw_ref);
Paul Crowleyf25a35a2015-05-06 13:38:53 +0100106
Paul Lawrence731a7a22015-04-28 22:14:15 +0000107static UnencryptedProperties GetProps(const char* path)
108{
109 return UnencryptedProperties(path);
110}
111
Paul Lawrence731a7a22015-04-28 22:14:15 +0000112int e4crypt_crypto_complete(const char* path)
113{
114 SLOGI("ext4 crypto complete called on %s", path);
Paul Lawrenceaec34df2016-02-03 10:52:41 -0800115 if (GetProps(path).Get<std::string>(properties::ref).empty()) {
116 SLOGI("No key reference, so not ext4enc");
Paul Lawrence731a7a22015-04-28 22:14:15 +0000117 return -1;
118 }
119
120 return 0;
121}
122
Paul Crowley93363482015-07-07 15:17:22 +0100123// Get raw keyref - used to make keyname and to pass to ioctl
Paul Lawrencefd7db732015-04-10 07:48:51 -0700124static std::string generate_key_ref(const char* key, int length)
125{
126 SHA512_CTX c;
127
128 SHA512_Init(&c);
129 SHA512_Update(&c, key, length);
Paul Crowley285956f2016-01-20 13:12:38 +0000130 unsigned char key_ref1[SHA512_DIGEST_LENGTH];
Paul Lawrencefd7db732015-04-10 07:48:51 -0700131 SHA512_Final(key_ref1, &c);
132
133 SHA512_Init(&c);
Paul Crowley285956f2016-01-20 13:12:38 +0000134 SHA512_Update(&c, key_ref1, SHA512_DIGEST_LENGTH);
135 unsigned char key_ref2[SHA512_DIGEST_LENGTH];
Paul Lawrencefd7db732015-04-10 07:48:51 -0700136 SHA512_Final(key_ref2, &c);
137
138 return std::string((char*)key_ref2, EXT4_KEY_DESCRIPTOR_SIZE);
139}
140
Paul Crowley93363482015-07-07 15:17:22 +0100141static ext4_encryption_key fill_key(const std::string &key)
Paul Crowleyf25a35a2015-05-06 13:38:53 +0100142{
Paul Lawrencefd7db732015-04-10 07:48:51 -0700143 // ext4enc:TODO Currently raw key is required to be of length
144 // sizeof(ext4_key.raw) == EXT4_MAX_KEY_SIZE, so zero pad to
145 // this length. Change when kernel bug is fixed.
146 ext4_encryption_key ext4_key = {EXT4_ENCRYPTION_MODE_AES_256_XTS,
147 {0},
148 sizeof(ext4_key.raw)};
149 memset(ext4_key.raw, 0, sizeof(ext4_key.raw));
150 static_assert(key_length / 8 <= sizeof(ext4_key.raw),
151 "Key too long!");
Paul Crowley95376d62015-05-06 15:04:43 +0100152 memcpy(ext4_key.raw, &key[0], key.size());
Paul Crowley93363482015-07-07 15:17:22 +0100153 return ext4_key;
154}
Paul Lawrence731a7a22015-04-28 22:14:15 +0000155
Paul Crowley93363482015-07-07 15:17:22 +0100156static std::string keyname(const std::string &raw_ref)
157{
Paul Lawrencefd7db732015-04-10 07:48:51 -0700158 std::ostringstream o;
Paul Crowley93363482015-07-07 15:17:22 +0100159 o << "ext4:";
Paul Lawrencefd7db732015-04-10 07:48:51 -0700160 for (auto i = raw_ref.begin(); i != raw_ref.end(); ++i) {
161 o << std::hex << std::setw(2) << std::setfill('0') << (int)*i;
162 }
Paul Crowley93363482015-07-07 15:17:22 +0100163 return o.str();
164}
Paul Lawrencefd7db732015-04-10 07:48:51 -0700165
Paul Crowley93363482015-07-07 15:17:22 +0100166// Get the keyring we store all keys in
167static key_serial_t e4crypt_keyring()
168{
169 return keyctl_search(KEY_SPEC_SESSION_KEYRING, "keyring", "e4crypt", 0);
170}
Paul Lawrence731a7a22015-04-28 22:14:15 +0000171
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000172// Install password into global keyring
173// Return raw key reference for use in policy
174static bool install_key(const std::string &key, std::string &raw_ref)
Paul Crowley93363482015-07-07 15:17:22 +0100175{
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000176 if (key.size() != key_length/8) {
177 LOG(ERROR) << "Wrong size key " << key.size();
178 return false;
179 }
180 auto ext4_key = fill_key(key);
181 raw_ref = generate_key_ref(ext4_key.raw, ext4_key.size);
182 auto ref = keyname(raw_ref);
Paul Crowley93363482015-07-07 15:17:22 +0100183 key_serial_t device_keyring = e4crypt_keyring();
Paul Lawrencefd7db732015-04-10 07:48:51 -0700184 key_serial_t key_id = add_key("logon", ref.c_str(),
Paul Lawrence731a7a22015-04-28 22:14:15 +0000185 (void*)&ext4_key, sizeof(ext4_key),
186 device_keyring);
Paul Lawrence731a7a22015-04-28 22:14:15 +0000187 if (key_id == -1) {
Paul Crowley285956f2016-01-20 13:12:38 +0000188 PLOG(ERROR) << "Failed to insert key into keyring " << device_keyring;
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000189 return false;
Paul Lawrence731a7a22015-04-28 22:14:15 +0000190 }
Paul Crowley285956f2016-01-20 13:12:38 +0000191 LOG(INFO) << "Added key " << key_id << " (" << ref << ") to keyring "
192 << device_keyring << " in process " << getpid();
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000193 return true;
Paul Lawrence731a7a22015-04-28 22:14:15 +0000194}
195
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000196static std::string get_de_key_path(userid_t user_id) {
197 return StringPrintf("%s/de/%d", user_key_dir.c_str(), user_id);
198}
199
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000200static std::string get_ce_key_path(userid_t user_id) {
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000201 return StringPrintf("%s/ce/%d/current", user_key_dir.c_str(), user_id);
Paul Crowleyb33e8872015-05-19 12:34:09 +0100202}
203
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000204static bool read_and_install_key(const std::string &key_path, std::string &raw_ref)
205{
206 std::string key;
207 if (!android::vold::retrieveKey(key_path, key)) return false;
208 if (!install_key(key, raw_ref)) return false;
209 return true;
Lenka Trochtova395039f2015-11-25 10:13:03 +0100210}
211
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000212static bool read_and_install_user_ce_key(userid_t user_id)
Paul Crowleyb33e8872015-05-19 12:34:09 +0100213{
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000214 if (s_ce_key_raw_refs.count(user_id) != 0) return true;
215 const auto key_path = get_ce_key_path(user_id);
216 std::string raw_ref;
217 if (!read_and_install_key(key_path, raw_ref)) return false;
218 s_ce_key_raw_refs[user_id] = raw_ref;
219 LOG(DEBUG) << "Installed ce key for user " << user_id;
Paul Crowley1ef25582016-01-21 20:26:12 +0000220 return true;
Paul Crowley285956f2016-01-20 13:12:38 +0000221}
222
Paul Crowley13ffd8e2016-01-27 14:30:22 +0000223static bool prepare_dir(const std::string &dir, mode_t mode, uid_t uid, gid_t gid) {
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000224 LOG(DEBUG) << "Preparing: " << dir;
Paul Crowley13ffd8e2016-01-27 14:30:22 +0000225 if (fs_prepare_dir(dir.c_str(), mode, uid, gid) != 0) {
226 PLOG(ERROR) << "Failed to prepare " << dir;
Paul Crowley285956f2016-01-20 13:12:38 +0000227 return false;
228 }
Paul Crowley13ffd8e2016-01-27 14:30:22 +0000229 return true;
230}
231
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000232static bool random_key(std::string &key) {
Paul Crowley1ef25582016-01-21 20:26:12 +0000233 if (android::vold::ReadRandomBytes(key_length / 8, key) != 0) {
234 // TODO status_t plays badly with PLOG, fix it.
235 LOG(ERROR) << "Random read failed";
Paul Crowley285956f2016-01-20 13:12:38 +0000236 return false;
237 }
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000238 return true;
239}
240
241static bool path_exists(const std::string &path) {
242 return access(path.c_str(), F_OK) == 0;
243}
244
245// NB this assumes that there is only one thread listening for crypt commands, because
246// it creates keys in a fixed location.
247static bool store_key(const std::string &key_path, const std::string &key) {
248 if (path_exists(key_path)) {
249 LOG(ERROR) << "Already exists, cannot create key at: " << key_path;
250 return false;
251 }
252 if (path_exists(user_key_temp)) {
253 android::vold::destroyKey(user_key_temp);
254 }
255 if (!android::vold::storeKey(user_key_temp, key)) return false;
256 if (rename(user_key_temp.c_str(), key_path.c_str()) != 0) {
257 PLOG(ERROR) << "Unable to move new key to location: " << key_path;
258 return false;
Paul Crowley95376d62015-05-06 15:04:43 +0100259 }
Paul Crowley285956f2016-01-20 13:12:38 +0000260 LOG(DEBUG) << "Created key " << key_path;
Paul Crowley95376d62015-05-06 15:04:43 +0100261 return true;
262}
263
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000264static bool create_and_install_user_keys(userid_t user_id, bool create_ephemeral) {
265 std::string de_key, ce_key;
266 if (!random_key(de_key)) return false;
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000267 if (!random_key(ce_key)) return false;
268 if (create_ephemeral) {
269 // If the key should be created as ephemeral, don't store it.
270 s_ephemeral_users.insert(user_id);
271 } else {
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000272 if (!store_key(get_de_key_path(user_id), de_key)) return false;
273 if (!prepare_dir(user_key_dir + "/ce/" + std::to_string(user_id),
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000274 0700, AID_ROOT, AID_ROOT)) return false;
275 if (!store_key(get_ce_key_path(user_id), ce_key)) return false;
Paul Crowley95376d62015-05-06 15:04:43 +0100276 }
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000277 std::string de_raw_ref;
278 if (!install_key(de_key, de_raw_ref)) return false;
279 s_de_key_raw_refs[user_id] = de_raw_ref;
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000280 std::string ce_raw_ref;
281 if (!install_key(ce_key, ce_raw_ref)) return false;
282 s_ce_key_raw_refs[user_id] = ce_raw_ref;
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000283 LOG(DEBUG) << "Created keys for user " << user_id;
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000284 return true;
285}
286
287static bool lookup_key_ref(const std::map<userid_t, std::string> &key_map,
288 userid_t user_id, std::string &raw_ref) {
289 auto refi = key_map.find(user_id);
290 if (refi == key_map.end()) {
291 LOG(ERROR) << "Cannot find key for " << user_id;
292 return false;
293 }
294 raw_ref = refi->second;
295 return true;
296}
297
298static bool set_policy(const std::string &raw_ref, const std::string& path) {
299 if (do_policy_set(path.c_str(), raw_ref.data(), raw_ref.size()) != 0) {
300 LOG(ERROR) << "Failed to set policy on: " << path;
301 return false;
302 }
303 return true;
Paul Crowley95376d62015-05-06 15:04:43 +0100304}
Paul Crowleyb33e8872015-05-19 12:34:09 +0100305
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000306static bool is_numeric(const char *name) {
307 for (const char *p = name; *p != '\0'; p++) {
308 if (!isdigit(*p))
309 return false;
310 }
311 return true;
312}
313
314static bool load_all_de_keys() {
315 auto de_dir = user_key_dir + "/de";
316 auto dirp = std::unique_ptr<DIR, int(*)(DIR*)>(opendir(de_dir.c_str()), closedir);
317 if (!dirp) {
318 PLOG(ERROR) << "Unable to read de key directory";
319 return false;
320 }
321 for (;;) {
322 errno = 0;
323 auto entry = readdir(dirp.get());
324 if (!entry) {
325 if (errno) {
326 PLOG(ERROR) << "Unable to read de key directory";
327 return false;
328 }
329 break;
330 }
331 if (entry->d_type != DT_DIR || !is_numeric(entry->d_name)) {
332 LOG(DEBUG) << "Skipping non-de-key " << entry->d_name;
333 continue;
334 }
335 userid_t user_id = atoi(entry->d_name);
336 if (s_de_key_raw_refs.count(user_id) == 0) {
337 std::string raw_ref;
338 if (!read_and_install_key(de_dir + "/" + entry->d_name, raw_ref)) return false;
339 s_de_key_raw_refs[user_id] = raw_ref;
340 LOG(DEBUG) << "Installed de key for user " << user_id;
341 }
342 }
343 // ext4enc:TODO: go through all DE directories, ensure that all user dirs have the
344 // correct policy set on them, and that no rogue ones exist.
345 return true;
346}
347
Paul Lawrenceaec34df2016-02-03 10:52:41 -0800348int e4crypt_enable(const char* path)
349{
350 LOG(INFO) << "e4crypt_enable";
351
352 if (s_enabled) {
353 LOG(INFO) << "Already enabled";
354 return 0;
355 }
356
357 std::string device_key;
Paul Lawrence5a06a642016-02-03 13:39:13 -0800358 std::string device_key_path = std::string(path) + device_key_leaf;
Paul Lawrenceaec34df2016-02-03 10:52:41 -0800359 if (!android::vold::retrieveKey(device_key_path, device_key)) {
360 LOG(INFO) << "Creating new key";
361 if (!random_key(device_key)) {
362 return -1;
363 }
364
Paul Lawrence5a06a642016-02-03 13:39:13 -0800365 std::string key_temp = std::string(path) + device_key_temp;
366 if (path_exists(key_temp)) {
367 android::vold::destroyKey(key_temp);
368 }
369
370 if (!android::vold::storeKey(key_temp, device_key)) return false;
371 if (rename(key_temp.c_str(), device_key_path.c_str()) != 0) {
372 PLOG(ERROR) << "Unable to move new key to location: "
373 << device_key_path;
374 return false;
Paul Lawrenceaec34df2016-02-03 10:52:41 -0800375 }
376 }
377
378 std::string device_key_ref;
379 if (!install_key(device_key, device_key_ref)) {
380 LOG(ERROR) << "Failed to install device key";
381 return -1;
382 }
383
384 UnencryptedProperties props(path);
385 if (!props.Remove(properties::ref)) {
Paul Lawrence5a06a642016-02-03 13:39:13 -0800386 LOG(ERROR) << "Failed to remove key ref";
Paul Lawrenceaec34df2016-02-03 10:52:41 -0800387 return -1;
388 }
389
390 if (!props.Set(properties::ref, device_key_ref)) {
Paul Lawrence5a06a642016-02-03 13:39:13 -0800391 LOG(ERROR) << "Cannot save key reference";
Paul Lawrenceaec34df2016-02-03 10:52:41 -0800392 return -1;
393 }
394
395 s_enabled = true;
396 return 0;
397}
398
Paul Crowley8fb12fd2016-02-01 14:28:12 +0000399int e4crypt_init_user0() {
400 LOG(DEBUG) << "e4crypt_init_user0";
401 if (e4crypt_is_native()) {
402 if (!prepare_dir(user_key_dir, 0700, AID_ROOT, AID_ROOT)) return -1;
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000403 if (!prepare_dir(user_key_dir + "/ce", 0700, AID_ROOT, AID_ROOT)) return -1;
404 if (!prepare_dir(user_key_dir + "/de", 0700, AID_ROOT, AID_ROOT)) return -1;
405 auto de_path = get_de_key_path(0);
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000406 auto ce_path = get_ce_key_path(0);
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000407 if (!path_exists(de_path) || !path_exists(ce_path)) {
408 if (path_exists(de_path)) {
409 android::vold::destroyKey(de_path); // Ignore failure
410 }
411 if (path_exists(ce_path)) {
412 android::vold::destroyKey(ce_path); // Ignore failure
413 }
414 if (!create_and_install_user_keys(0, false)) return -1;
Paul Crowley8fb12fd2016-02-01 14:28:12 +0000415 }
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000416 if (!load_all_de_keys()) return -1;
Paul Crowley8fb12fd2016-02-01 14:28:12 +0000417 }
418 // Ignore failures. FIXME this is horrid
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000419 // FIXME: we need an idempotent policy-setting call, which simply verifies the
420 // policy is already set on a second run, even if the directory is nonempty.
421 // Then we need to call it all the time.
Paul Crowley8fb12fd2016-02-01 14:28:12 +0000422 e4crypt_prepare_user_storage(nullptr, 0, 0, false);
423 return 0;
424}
425
Paul Crowley27cbce92015-12-10 14:51:30 +0000426int e4crypt_vold_create_user_key(userid_t user_id, int serial, bool ephemeral) {
Paul Crowley285956f2016-01-20 13:12:38 +0000427 LOG(DEBUG) << "e4crypt_vold_create_user_key for " << user_id << " serial " << serial;
Paul Crowleyea62e262016-01-28 12:23:53 +0000428 if (!e4crypt_is_native()) {
429 return 0;
430 }
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000431 // FIXME test for existence of key that is not loaded yet
432 if (s_ce_key_raw_refs.count(user_id) != 0) {
Paul Crowley285956f2016-01-20 13:12:38 +0000433 LOG(ERROR) << "Already exists, can't e4crypt_vold_create_user_key for "
434 << user_id << " serial " << serial;
435 // FIXME should we fail the command?
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800436 return 0;
437 }
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000438 if (!create_and_install_user_keys(user_id, ephemeral)) {
Paul Crowley285956f2016-01-20 13:12:38 +0000439 return -1;
440 }
441 // TODO: create second key for user_de data
442 return 0;
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800443}
444
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000445static bool evict_key(const std::string &raw_ref) {
446 auto ref = keyname(raw_ref);
Paul Crowley93363482015-07-07 15:17:22 +0100447 auto key_serial = keyctl_search(e4crypt_keyring(), "logon", ref.c_str(), 0);
Paul Crowley1ef25582016-01-21 20:26:12 +0000448 if (keyctl_revoke(key_serial) != 0) {
Paul Crowley285956f2016-01-20 13:12:38 +0000449 PLOG(ERROR) << "Failed to revoke key with serial " << key_serial << " ref " << ref;
Paul Crowley1ef25582016-01-21 20:26:12 +0000450 return false;
Paul Crowley93363482015-07-07 15:17:22 +0100451 }
Paul Crowley1ef25582016-01-21 20:26:12 +0000452 LOG(DEBUG) << "Revoked key with serial " << key_serial << " ref " << ref;
453 return true;
454}
455
456int e4crypt_destroy_user_key(userid_t user_id) {
457 LOG(DEBUG) << "e4crypt_destroy_user_key(" << user_id << ")";
Paul Crowleyea62e262016-01-28 12:23:53 +0000458 if (!e4crypt_is_native()) {
459 return 0;
460 }
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000461 bool success = true;
462 std::string raw_ref;
463 success &= lookup_key_ref(s_ce_key_raw_refs, user_id, raw_ref) && evict_key(raw_ref);
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000464 success &= lookup_key_ref(s_de_key_raw_refs, user_id, raw_ref) && evict_key(raw_ref);
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000465 auto it = s_ephemeral_users.find(user_id);
466 if (it != s_ephemeral_users.end()) {
467 s_ephemeral_users.erase(it);
Paul Crowley1ef25582016-01-21 20:26:12 +0000468 } else {
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000469 success &= android::vold::destroyKey(get_ce_key_path(user_id));
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000470 success &= android::vold::destroyKey(get_de_key_path(user_id));
Lenka Trochtova395039f2015-11-25 10:13:03 +0100471 }
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000472 return success ? 0 : -1;
Paul Crowleyb33e8872015-05-19 12:34:09 +0100473}
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800474
Jeff Sharkey7a9dd952016-01-12 16:52:16 -0700475static int emulated_lock(const std::string& path) {
476 if (chmod(path.c_str(), 0000) != 0) {
477 PLOG(ERROR) << "Failed to chmod " << path;
478 return -1;
479 }
480#if EMULATED_USES_SELINUX
481 if (setfilecon(path.c_str(), "u:object_r:storage_stub_file:s0") != 0) {
482 PLOG(WARNING) << "Failed to setfilecon " << path;
483 return -1;
484 }
485#endif
486 return 0;
487}
488
489static int emulated_unlock(const std::string& path, mode_t mode) {
490 if (chmod(path.c_str(), mode) != 0) {
491 PLOG(ERROR) << "Failed to chmod " << path;
Paul Crowleya042cb52016-01-21 17:24:49 +0000492 // FIXME temporary workaround for b/26713622
493 if (e4crypt_is_emulated()) return -1;
Jeff Sharkey7a9dd952016-01-12 16:52:16 -0700494 }
495#if EMULATED_USES_SELINUX
496 if (selinux_android_restorecon(path.c_str(), SELINUX_ANDROID_RESTORECON_FORCE) != 0) {
497 PLOG(WARNING) << "Failed to restorecon " << path;
Paul Crowleya042cb52016-01-21 17:24:49 +0000498 // FIXME temporary workaround for b/26713622
499 if (e4crypt_is_emulated()) return -1;
Jeff Sharkey7a9dd952016-01-12 16:52:16 -0700500 }
501#endif
502 return 0;
503}
504
Paul Crowley285956f2016-01-20 13:12:38 +0000505int e4crypt_unlock_user_key(userid_t user_id, int serial, const char* token) {
506 LOG(DEBUG) << "e4crypt_unlock_user_key " << user_id << " " << (token != nullptr);
Jeff Sharkeyfc505c32015-12-07 17:27:01 -0700507 if (e4crypt_is_native()) {
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000508 if (!read_and_install_user_ce_key(user_id)) {
Paul Crowley8fb12fd2016-02-01 14:28:12 +0000509 LOG(ERROR) << "Couldn't read key for " << user_id;
510 return -1;
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800511 }
Jeff Sharkeyfc505c32015-12-07 17:27:01 -0700512 } else {
513 // When in emulation mode, we just use chmod. However, we also
514 // unlock directories when not in emulation mode, to bring devices
515 // back into a known-good state.
Jeff Sharkey7a9dd952016-01-12 16:52:16 -0700516 if (emulated_unlock(android::vold::BuildDataSystemCePath(user_id), 0771) ||
517 emulated_unlock(android::vold::BuildDataMediaPath(nullptr, user_id), 0770) ||
518 emulated_unlock(android::vold::BuildDataUserPath(nullptr, user_id), 0771)) {
519 LOG(ERROR) << "Failed to unlock user " << user_id;
Jeff Sharkeyfc505c32015-12-07 17:27:01 -0700520 return -1;
521 }
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800522 }
523 return 0;
524}
525
526int e4crypt_lock_user_key(userid_t user_id) {
Jeff Sharkeyfc505c32015-12-07 17:27:01 -0700527 if (e4crypt_is_native()) {
528 // TODO: remove from kernel keyring
529 } else if (e4crypt_is_emulated()) {
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800530 // When in emulation mode, we just use chmod
Jeff Sharkey7a9dd952016-01-12 16:52:16 -0700531 if (emulated_lock(android::vold::BuildDataSystemCePath(user_id)) ||
532 emulated_lock(android::vold::BuildDataMediaPath(nullptr, user_id)) ||
533 emulated_lock(android::vold::BuildDataUserPath(nullptr, user_id))) {
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800534 PLOG(ERROR) << "Failed to lock user " << user_id;
535 return -1;
536 }
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800537 }
Jeff Sharkeyfc505c32015-12-07 17:27:01 -0700538
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800539 return 0;
540}
541
Lenka Trochtova9ad43692015-12-11 13:27:26 +0100542int e4crypt_prepare_user_storage(const char* volume_uuid,
543 userid_t user_id,
544 int serial,
545 bool ephemeral) {
Paul Crowley285956f2016-01-20 13:12:38 +0000546 if (volume_uuid) {
547 LOG(DEBUG) << "e4crypt_prepare_user_storage " << volume_uuid << " " << user_id;
548 } else {
549 LOG(DEBUG) << "e4crypt_prepare_user_storage, null volume " << user_id;
550 }
Paul Crowley13ffd8e2016-01-27 14:30:22 +0000551 auto system_ce_path = android::vold::BuildDataSystemCePath(user_id);
552 auto media_ce_path = android::vold::BuildDataMediaPath(volume_uuid, user_id);
553 auto user_ce_path = android::vold::BuildDataUserPath(volume_uuid, user_id);
554 auto user_de_path = android::vold::BuildDataUserDePath(volume_uuid, user_id);
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800555
Paul Crowley8fb12fd2016-02-01 14:28:12 +0000556 // FIXME: should this be 0770 or 0700?
557 if (!prepare_dir(system_ce_path, 0770, AID_SYSTEM, AID_SYSTEM)) return -1;
Paul Crowley13ffd8e2016-01-27 14:30:22 +0000558 if (!prepare_dir(media_ce_path, 0770, AID_MEDIA_RW, AID_MEDIA_RW)) return -1;
559 if (!prepare_dir(user_ce_path, 0771, AID_SYSTEM, AID_SYSTEM)) return -1;
560 if (!prepare_dir(user_de_path, 0771, AID_SYSTEM, AID_SYSTEM)) return -1;
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800561
562 if (e4crypt_crypto_complete(DATA_MNT_POINT) == 0) {
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000563 std::string ce_raw_ref, de_raw_ref;
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000564 if (!lookup_key_ref(s_ce_key_raw_refs, user_id, ce_raw_ref)) return -1;
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000565 if (!lookup_key_ref(s_de_key_raw_refs, user_id, de_raw_ref)) return -1;
Paul Crowleyb1f3d242016-01-28 10:09:46 +0000566 if (!set_policy(ce_raw_ref, system_ce_path)) return -1;
567 if (!set_policy(ce_raw_ref, media_ce_path)) return -1;
568 if (!set_policy(ce_raw_ref, user_ce_path)) return -1;
Paul Crowleyb92f83c2016-02-01 14:10:43 +0000569 if (!set_policy(de_raw_ref, user_de_path)) return -1;
570 // FIXME I thought there were more DE directories than this
Jeff Sharkeyd2c96e72015-11-08 17:56:23 -0800571 }
572
573 return 0;
574}