Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 1 | /* |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 2 | * Copyright (C) 2016 The Android Open Source Project |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 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 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 17 | #include "keystore.h" |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 18 | |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 19 | #include <dirent.h> |
| 20 | #include <fcntl.h> |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 21 | |
Kenny Root | 822c3a9 | 2012-03-23 16:34:39 -0700 | [diff] [blame] | 22 | #include <openssl/bio.h> |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 23 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 24 | #include <utils/String16.h> |
Kenny Root | 70e3a86 | 2012-02-15 17:20:23 -0800 | [diff] [blame] | 25 | |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 26 | #include <keystore/IKeystoreService.h> |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 27 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 28 | #include "keystore_utils.h" |
| 29 | #include "permissions.h" |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 30 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 31 | const char* KeyStore::sOldMasterKey = ".masterkey"; |
| 32 | const char* KeyStore::sMetaDataFile = ".metadata"; |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 33 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 34 | const android::String16 KeyStore::sRSAKeyType("RSA"); |
| 35 | const android::String16 KeyStore::sECKeyType("EC"); |
Riley Spahn | eaabae9 | 2014-06-30 12:39:52 -0700 | [diff] [blame] | 36 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 37 | KeyStore::KeyStore(Entropy* entropy, keymaster1_device_t* device, keymaster1_device_t* fallback) |
| 38 | : mEntropy(entropy), mDevice(device), mFallbackDevice(fallback) { |
| 39 | memset(&mMetaData, '\0', sizeof(mMetaData)); |
Kenny Root | 70e3a86 | 2012-02-15 17:20:23 -0800 | [diff] [blame] | 40 | } |
| 41 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 42 | KeyStore::~KeyStore() { |
| 43 | for (android::Vector<grant_t*>::iterator it(mGrants.begin()); it != mGrants.end(); it++) { |
| 44 | delete *it; |
Shawn Willden | 55268b5 | 2015-07-28 11:06:00 -0600 | [diff] [blame] | 45 | } |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 46 | mGrants.clear(); |
Shawn Willden | 55268b5 | 2015-07-28 11:06:00 -0600 | [diff] [blame] | 47 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 48 | for (android::Vector<UserState*>::iterator it(mMasterKeys.begin()); it != mMasterKeys.end(); |
| 49 | it++) { |
| 50 | delete *it; |
Shawn Willden | 55268b5 | 2015-07-28 11:06:00 -0600 | [diff] [blame] | 51 | } |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 52 | mMasterKeys.clear(); |
Shawn Willden | 55268b5 | 2015-07-28 11:06:00 -0600 | [diff] [blame] | 53 | } |
| 54 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 55 | ResponseCode KeyStore::initialize() { |
| 56 | readMetaData(); |
| 57 | if (upgradeKeystore()) { |
| 58 | writeMetaData(); |
Shawn Willden | 55268b5 | 2015-07-28 11:06:00 -0600 | [diff] [blame] | 59 | } |
| 60 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 61 | return ::NO_ERROR; |
Shawn Willden | 55268b5 | 2015-07-28 11:06:00 -0600 | [diff] [blame] | 62 | } |
| 63 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 64 | ResponseCode KeyStore::initializeUser(const android::String8& pw, uid_t userId) { |
| 65 | UserState* userState = getUserState(userId); |
| 66 | return userState->initialize(pw, mEntropy); |
Chad Brubaker | fc18edc | 2015-01-12 15:17:18 -0800 | [diff] [blame] | 67 | } |
| 68 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 69 | ResponseCode KeyStore::copyMasterKey(uid_t srcUser, uid_t dstUser) { |
| 70 | UserState* userState = getUserState(dstUser); |
| 71 | UserState* initState = getUserState(srcUser); |
| 72 | return userState->copyMasterKey(initState); |
Kenny Root | 70e3a86 | 2012-02-15 17:20:23 -0800 | [diff] [blame] | 73 | } |
| 74 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 75 | ResponseCode KeyStore::writeMasterKey(const android::String8& pw, uid_t userId) { |
| 76 | UserState* userState = getUserState(userId); |
| 77 | return userState->writeMasterKey(pw, mEntropy); |
Shawn Willden | 55268b5 | 2015-07-28 11:06:00 -0600 | [diff] [blame] | 78 | } |
| 79 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 80 | ResponseCode KeyStore::readMasterKey(const android::String8& pw, uid_t userId) { |
| 81 | UserState* userState = getUserState(userId); |
| 82 | return userState->readMasterKey(pw, mEntropy); |
Kenny Root | 4946890 | 2013-03-19 13:41:33 -0700 | [diff] [blame] | 83 | } |
| 84 | |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 85 | /* Here is the encoding of keys. This is necessary in order to allow arbitrary |
| 86 | * characters in keys. Characters in [0-~] are not encoded. Others are encoded |
| 87 | * into two bytes. The first byte is one of [+-.] which represents the first |
| 88 | * two bits of the character. The second byte encodes the rest of the bits into |
| 89 | * [0-o]. Therefore in the worst case the length of a key gets doubled. Note |
| 90 | * that Base64 cannot be used here due to the need of prefix match on keys. */ |
| 91 | |
Kenny Root | 655b958 | 2013-04-04 08:37:42 -0700 | [diff] [blame] | 92 | static size_t encode_key_length(const android::String8& keyName) { |
| 93 | const uint8_t* in = reinterpret_cast<const uint8_t*>(keyName.string()); |
| 94 | size_t length = keyName.length(); |
| 95 | for (int i = length; i > 0; --i, ++in) { |
| 96 | if (*in < '0' || *in > '~') { |
| 97 | ++length; |
| 98 | } |
| 99 | } |
| 100 | return length; |
| 101 | } |
| 102 | |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 103 | static int encode_key(char* out, const android::String8& keyName) { |
| 104 | const uint8_t* in = reinterpret_cast<const uint8_t*>(keyName.string()); |
| 105 | size_t length = keyName.length(); |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 106 | for (int i = length; i > 0; --i, ++in, ++out) { |
Kenny Root | 655b958 | 2013-04-04 08:37:42 -0700 | [diff] [blame] | 107 | if (*in < '0' || *in > '~') { |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 108 | *out = '+' + (*in >> 6); |
| 109 | *++out = '0' + (*in & 0x3F); |
| 110 | ++length; |
Kenny Root | 655b958 | 2013-04-04 08:37:42 -0700 | [diff] [blame] | 111 | } else { |
| 112 | *out = *in; |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 113 | } |
| 114 | } |
| 115 | *out = '\0'; |
Kenny Root | 70e3a86 | 2012-02-15 17:20:23 -0800 | [diff] [blame] | 116 | return length; |
| 117 | } |
| 118 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 119 | android::String8 KeyStore::getKeyName(const android::String8& keyName) { |
| 120 | char encoded[encode_key_length(keyName) + 1]; // add 1 for null char |
| 121 | encode_key(encoded, keyName); |
| 122 | return android::String8(encoded); |
| 123 | } |
| 124 | |
| 125 | android::String8 KeyStore::getKeyNameForUid(const android::String8& keyName, uid_t uid) { |
| 126 | char encoded[encode_key_length(keyName) + 1]; // add 1 for null char |
| 127 | encode_key(encoded, keyName); |
| 128 | return android::String8::format("%u_%s", uid, encoded); |
| 129 | } |
| 130 | |
| 131 | android::String8 KeyStore::getKeyNameForUidWithDir(const android::String8& keyName, uid_t uid) { |
| 132 | char encoded[encode_key_length(keyName) + 1]; // add 1 for null char |
| 133 | encode_key(encoded, keyName); |
| 134 | return android::String8::format("%s/%u_%s", getUserStateByUid(uid)->getUserDirName(), uid, |
| 135 | encoded); |
| 136 | } |
| 137 | |
| 138 | void KeyStore::resetUser(uid_t userId, bool keepUnenryptedEntries) { |
| 139 | android::String8 prefix(""); |
| 140 | android::Vector<android::String16> aliases; |
| 141 | UserState* userState = getUserState(userId); |
| 142 | if (list(prefix, &aliases, userId) != ::NO_ERROR) { |
| 143 | return; |
| 144 | } |
| 145 | for (uint32_t i = 0; i < aliases.size(); i++) { |
| 146 | android::String8 filename(aliases[i]); |
| 147 | filename = android::String8::format("%s/%s", userState->getUserDirName(), |
| 148 | getKeyName(filename).string()); |
| 149 | bool shouldDelete = true; |
| 150 | if (keepUnenryptedEntries) { |
| 151 | Blob blob; |
| 152 | ResponseCode rc = get(filename, &blob, ::TYPE_ANY, userId); |
| 153 | |
| 154 | /* get can fail if the blob is encrypted and the state is |
| 155 | * not unlocked, only skip deleting blobs that were loaded and |
| 156 | * who are not encrypted. If there are blobs we fail to read for |
| 157 | * other reasons err on the safe side and delete them since we |
| 158 | * can't tell if they're encrypted. |
| 159 | */ |
| 160 | shouldDelete = !(rc == ::NO_ERROR && !blob.isEncrypted()); |
| 161 | } |
| 162 | if (shouldDelete) { |
| 163 | del(filename, ::TYPE_ANY, userId); |
| 164 | } |
| 165 | } |
| 166 | if (!userState->deleteMasterKey()) { |
| 167 | ALOGE("Failed to delete user %d's master key", userId); |
| 168 | } |
| 169 | if (!keepUnenryptedEntries) { |
| 170 | if (!userState->reset()) { |
| 171 | ALOGE("Failed to remove user %d's directory", userId); |
| 172 | } |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | bool KeyStore::isEmpty(uid_t userId) const { |
| 177 | const UserState* userState = getUserState(userId); |
| 178 | if (userState == NULL) { |
| 179 | return true; |
| 180 | } |
| 181 | |
| 182 | DIR* dir = opendir(userState->getUserDirName()); |
| 183 | if (!dir) { |
| 184 | return true; |
| 185 | } |
| 186 | |
| 187 | bool result = true; |
| 188 | struct dirent* file; |
| 189 | while ((file = readdir(dir)) != NULL) { |
| 190 | // We only care about files. |
| 191 | if (file->d_type != DT_REG) { |
| 192 | continue; |
| 193 | } |
| 194 | |
| 195 | // Skip anything that starts with a "." |
| 196 | if (file->d_name[0] == '.') { |
| 197 | continue; |
| 198 | } |
| 199 | |
| 200 | result = false; |
| 201 | break; |
| 202 | } |
| 203 | closedir(dir); |
| 204 | return result; |
| 205 | } |
| 206 | |
| 207 | void KeyStore::lock(uid_t userId) { |
| 208 | UserState* userState = getUserState(userId); |
| 209 | userState->zeroizeMasterKeysInMemory(); |
| 210 | userState->setState(STATE_LOCKED); |
| 211 | } |
| 212 | |
| 213 | ResponseCode KeyStore::get(const char* filename, Blob* keyBlob, const BlobType type, uid_t userId) { |
| 214 | UserState* userState = getUserState(userId); |
| 215 | ResponseCode rc = |
| 216 | keyBlob->readBlob(filename, userState->getDecryptionKey(), userState->getState()); |
| 217 | if (rc != NO_ERROR) { |
| 218 | return rc; |
| 219 | } |
| 220 | |
| 221 | const uint8_t version = keyBlob->getVersion(); |
| 222 | if (version < CURRENT_BLOB_VERSION) { |
| 223 | /* If we upgrade the key, we need to write it to disk again. Then |
| 224 | * it must be read it again since the blob is encrypted each time |
| 225 | * it's written. |
| 226 | */ |
| 227 | if (upgradeBlob(filename, keyBlob, version, type, userId)) { |
| 228 | if ((rc = this->put(filename, keyBlob, userId)) != NO_ERROR || |
| 229 | (rc = keyBlob->readBlob(filename, userState->getDecryptionKey(), |
| 230 | userState->getState())) != NO_ERROR) { |
| 231 | return rc; |
| 232 | } |
| 233 | } |
| 234 | } |
| 235 | |
| 236 | /* |
| 237 | * This will upgrade software-backed keys to hardware-backed keys when |
| 238 | * the HAL for the device supports the newer key types. |
| 239 | */ |
| 240 | if (rc == NO_ERROR && type == TYPE_KEY_PAIR && |
| 241 | mDevice->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_0_2 && |
| 242 | keyBlob->isFallback()) { |
| 243 | ResponseCode imported = |
| 244 | importKey(keyBlob->getValue(), keyBlob->getLength(), filename, userId, |
| 245 | keyBlob->isEncrypted() ? KEYSTORE_FLAG_ENCRYPTED : KEYSTORE_FLAG_NONE); |
| 246 | |
| 247 | // The HAL allowed the import, reget the key to have the "fresh" |
| 248 | // version. |
| 249 | if (imported == NO_ERROR) { |
| 250 | rc = get(filename, keyBlob, TYPE_KEY_PAIR, userId); |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | // Keymaster 0.3 keys are valid keymaster 1.0 keys, so silently upgrade. |
| 255 | if (keyBlob->getType() == TYPE_KEY_PAIR) { |
| 256 | keyBlob->setType(TYPE_KEYMASTER_10); |
| 257 | rc = this->put(filename, keyBlob, userId); |
| 258 | } |
| 259 | |
| 260 | if (type != TYPE_ANY && keyBlob->getType() != type) { |
| 261 | ALOGW("key found but type doesn't match: %d vs %d", keyBlob->getType(), type); |
| 262 | return KEY_NOT_FOUND; |
| 263 | } |
| 264 | |
| 265 | return rc; |
| 266 | } |
| 267 | |
| 268 | ResponseCode KeyStore::put(const char* filename, Blob* keyBlob, uid_t userId) { |
| 269 | UserState* userState = getUserState(userId); |
| 270 | return keyBlob->writeBlob(filename, userState->getEncryptionKey(), userState->getState(), |
| 271 | mEntropy); |
| 272 | } |
| 273 | |
| 274 | ResponseCode KeyStore::del(const char* filename, const BlobType type, uid_t userId) { |
| 275 | Blob keyBlob; |
| 276 | ResponseCode rc = get(filename, &keyBlob, type, userId); |
| 277 | if (rc == ::VALUE_CORRUPTED) { |
| 278 | // The file is corrupt, the best we can do is rm it. |
| 279 | return (unlink(filename) && errno != ENOENT) ? ::SYSTEM_ERROR : ::NO_ERROR; |
| 280 | } |
| 281 | if (rc != ::NO_ERROR) { |
| 282 | return rc; |
| 283 | } |
| 284 | |
| 285 | if (keyBlob.getType() == ::TYPE_KEY_PAIR) { |
| 286 | // A device doesn't have to implement delete_key. |
| 287 | if (mDevice->delete_key != NULL && !keyBlob.isFallback()) { |
| 288 | keymaster_key_blob_t blob = {keyBlob.getValue(), |
| 289 | static_cast<size_t>(keyBlob.getLength())}; |
| 290 | if (mDevice->delete_key(mDevice, &blob)) { |
| 291 | rc = ::SYSTEM_ERROR; |
| 292 | } |
| 293 | } |
| 294 | } |
| 295 | if (keyBlob.getType() == ::TYPE_KEYMASTER_10) { |
| 296 | keymaster1_device_t* dev = getDeviceForBlob(keyBlob); |
| 297 | if (dev->delete_key) { |
| 298 | keymaster_key_blob_t blob; |
| 299 | blob.key_material = keyBlob.getValue(); |
| 300 | blob.key_material_size = keyBlob.getLength(); |
| 301 | dev->delete_key(dev, &blob); |
| 302 | } |
| 303 | } |
| 304 | if (rc != ::NO_ERROR) { |
| 305 | return rc; |
| 306 | } |
| 307 | |
| 308 | return (unlink(filename) && errno != ENOENT) ? ::SYSTEM_ERROR : ::NO_ERROR; |
| 309 | } |
| 310 | |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 311 | /* |
| 312 | * Converts from the "escaped" format on disk to actual name. |
| 313 | * This will be smaller than the input string. |
| 314 | * |
| 315 | * Characters that should combine with the next at the end will be truncated. |
| 316 | */ |
| 317 | static size_t decode_key_length(const char* in, size_t length) { |
| 318 | size_t outLength = 0; |
| 319 | |
| 320 | for (const char* end = in + length; in < end; in++) { |
| 321 | /* This combines with the next character. */ |
| 322 | if (*in < '0' || *in > '~') { |
| 323 | continue; |
| 324 | } |
| 325 | |
| 326 | outLength++; |
| 327 | } |
| 328 | return outLength; |
| 329 | } |
| 330 | |
| 331 | static void decode_key(char* out, const char* in, size_t length) { |
| 332 | for (const char* end = in + length; in < end; in++) { |
| 333 | if (*in < '0' || *in > '~') { |
| 334 | /* Truncate combining characters at the end. */ |
| 335 | if (in + 1 >= end) { |
| 336 | break; |
| 337 | } |
| 338 | |
| 339 | *out = (*in++ - '+') << 6; |
| 340 | *out++ |= (*in - '0') & 0x3F; |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 341 | } else { |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 342 | *out++ = *in; |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 343 | } |
| 344 | } |
| 345 | *out = '\0'; |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 346 | } |
| 347 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 348 | ResponseCode KeyStore::list(const android::String8& prefix, |
| 349 | android::Vector<android::String16>* matches, uid_t userId) { |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 350 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 351 | UserState* userState = getUserState(userId); |
| 352 | size_t n = prefix.length(); |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 353 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 354 | DIR* dir = opendir(userState->getUserDirName()); |
| 355 | if (!dir) { |
| 356 | ALOGW("can't open directory for user: %s", strerror(errno)); |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 357 | return ::SYSTEM_ERROR; |
| 358 | } |
| 359 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 360 | struct dirent* file; |
| 361 | while ((file = readdir(dir)) != NULL) { |
| 362 | // We only care about files. |
| 363 | if (file->d_type != DT_REG) { |
| 364 | continue; |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 365 | } |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 366 | |
| 367 | // Skip anything that starts with a "." |
| 368 | if (file->d_name[0] == '.') { |
| 369 | continue; |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 370 | } |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 371 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 372 | if (!strncmp(prefix.string(), file->d_name, n)) { |
| 373 | const char* p = &file->d_name[n]; |
| 374 | size_t plen = strlen(p); |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 375 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 376 | size_t extra = decode_key_length(p, plen); |
| 377 | char* match = (char*)malloc(extra + 1); |
| 378 | if (match != NULL) { |
| 379 | decode_key(match, p, plen); |
| 380 | matches->push(android::String16(match, extra)); |
| 381 | free(match); |
Chad Brubaker | df70517 | 2015-06-17 20:17:51 -0700 | [diff] [blame] | 382 | } else { |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 383 | ALOGW("could not allocate match of size %zd", extra); |
Chad Brubaker | df70517 | 2015-06-17 20:17:51 -0700 | [diff] [blame] | 384 | } |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 385 | } |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 386 | } |
| 387 | closedir(dir); |
| 388 | return ::NO_ERROR; |
| 389 | } |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 390 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 391 | void KeyStore::addGrant(const char* filename, uid_t granteeUid) { |
| 392 | const grant_t* existing = getGrant(filename, granteeUid); |
| 393 | if (existing == NULL) { |
| 394 | grant_t* grant = new grant_t; |
| 395 | grant->uid = granteeUid; |
| 396 | grant->filename = reinterpret_cast<const uint8_t*>(strdup(filename)); |
| 397 | mGrants.add(grant); |
| 398 | } |
| 399 | } |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 400 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 401 | bool KeyStore::removeGrant(const char* filename, uid_t granteeUid) { |
| 402 | for (android::Vector<grant_t*>::iterator it(mGrants.begin()); it != mGrants.end(); it++) { |
| 403 | grant_t* grant = *it; |
| 404 | if (grant->uid == granteeUid && |
| 405 | !strcmp(reinterpret_cast<const char*>(grant->filename), filename)) { |
| 406 | mGrants.erase(it); |
| 407 | return true; |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 408 | } |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 409 | } |
| 410 | return false; |
| 411 | } |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 412 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 413 | ResponseCode KeyStore::importKey(const uint8_t* key, size_t keyLen, const char* filename, |
| 414 | uid_t userId, int32_t flags) { |
| 415 | Unique_PKCS8_PRIV_KEY_INFO pkcs8(d2i_PKCS8_PRIV_KEY_INFO(NULL, &key, keyLen)); |
| 416 | if (!pkcs8.get()) { |
| 417 | return ::SYSTEM_ERROR; |
| 418 | } |
| 419 | Unique_EVP_PKEY pkey(EVP_PKCS82PKEY(pkcs8.get())); |
| 420 | if (!pkey.get()) { |
| 421 | return ::SYSTEM_ERROR; |
| 422 | } |
| 423 | int type = EVP_PKEY_type(pkey->type); |
| 424 | android::KeymasterArguments params; |
| 425 | add_legacy_key_authorizations(type, ¶ms.params); |
| 426 | switch (type) { |
| 427 | case EVP_PKEY_RSA: |
| 428 | params.params.push_back(keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_RSA)); |
| 429 | break; |
| 430 | case EVP_PKEY_EC: |
| 431 | params.params.push_back(keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_EC)); |
| 432 | break; |
| 433 | default: |
| 434 | ALOGW("Unsupported key type %d", type); |
| 435 | return ::SYSTEM_ERROR; |
Chad Brubaker | 3a7d9e6 | 2015-06-04 15:01:46 -0700 | [diff] [blame] | 436 | } |
| 437 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 438 | std::vector<keymaster_key_param_t> opParams(params.params); |
| 439 | const keymaster_key_param_set_t inParams = {opParams.data(), opParams.size()}; |
| 440 | keymaster_blob_t input = {key, keyLen}; |
| 441 | keymaster_key_blob_t blob = {nullptr, 0}; |
| 442 | bool isFallback = false; |
| 443 | keymaster_error_t error = mDevice->import_key(mDevice, &inParams, KM_KEY_FORMAT_PKCS8, &input, |
| 444 | &blob, NULL /* characteristics */); |
| 445 | if (error != KM_ERROR_OK) { |
| 446 | ALOGE("Keymaster error %d importing key pair, falling back", error); |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 447 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 448 | /* |
| 449 | * There should be no way to get here. Fallback shouldn't ever really happen |
| 450 | * because the main device may be many (SW, KM0/SW hybrid, KM1/SW hybrid), but it must |
| 451 | * provide full support of the API. In any case, we'll do the fallback just for |
| 452 | * consistency... and I suppose to cover for broken HW implementations. |
| 453 | */ |
| 454 | error = mFallbackDevice->import_key(mFallbackDevice, &inParams, KM_KEY_FORMAT_PKCS8, &input, |
| 455 | &blob, NULL /* characteristics */); |
| 456 | isFallback = true; |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 457 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 458 | if (error) { |
| 459 | ALOGE("Keymaster error while importing key pair with fallback: %d", error); |
| 460 | return SYSTEM_ERROR; |
Riley Spahn | eaabae9 | 2014-06-30 12:39:52 -0700 | [diff] [blame] | 461 | } |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 462 | } |
| 463 | |
| 464 | Blob keyBlob(blob.key_material, blob.key_material_size, NULL, 0, TYPE_KEYMASTER_10); |
| 465 | free(const_cast<uint8_t*>(blob.key_material)); |
| 466 | |
| 467 | keyBlob.setEncrypted(flags & KEYSTORE_FLAG_ENCRYPTED); |
| 468 | keyBlob.setFallback(isFallback); |
| 469 | |
| 470 | return put(filename, &keyBlob, userId); |
| 471 | } |
| 472 | |
| 473 | bool KeyStore::isHardwareBacked(const android::String16& keyType) const { |
| 474 | if (mDevice == NULL) { |
| 475 | ALOGW("can't get keymaster device"); |
| 476 | return false; |
| 477 | } |
| 478 | |
| 479 | if (sRSAKeyType == keyType) { |
| 480 | return (mDevice->flags & KEYMASTER_SOFTWARE_ONLY) == 0; |
Riley Spahn | eaabae9 | 2014-06-30 12:39:52 -0700 | [diff] [blame] | 481 | } else { |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 482 | return (mDevice->flags & KEYMASTER_SOFTWARE_ONLY) == 0 && |
| 483 | (mDevice->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_0_2); |
| 484 | } |
| 485 | } |
| 486 | |
| 487 | ResponseCode KeyStore::getKeyForName(Blob* keyBlob, const android::String8& keyName, |
| 488 | const uid_t uid, const BlobType type) { |
| 489 | android::String8 filepath8(getKeyNameForUidWithDir(keyName, uid)); |
| 490 | uid_t userId = get_user_id(uid); |
| 491 | |
| 492 | ResponseCode responseCode = get(filepath8.string(), keyBlob, type, userId); |
| 493 | if (responseCode == NO_ERROR) { |
| 494 | return responseCode; |
Riley Spahn | eaabae9 | 2014-06-30 12:39:52 -0700 | [diff] [blame] | 495 | } |
| 496 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 497 | // If this is one of the legacy UID->UID mappings, use it. |
| 498 | uid_t euid = get_keystore_euid(uid); |
| 499 | if (euid != uid) { |
| 500 | filepath8 = getKeyNameForUidWithDir(keyName, euid); |
| 501 | responseCode = get(filepath8.string(), keyBlob, type, userId); |
| 502 | if (responseCode == NO_ERROR) { |
| 503 | return responseCode; |
| 504 | } |
| 505 | } |
| 506 | |
| 507 | // They might be using a granted key. |
| 508 | android::String8 filename8 = getKeyName(keyName); |
| 509 | char* end; |
| 510 | strtoul(filename8.string(), &end, 10); |
| 511 | if (end[0] != '_' || end[1] == 0) { |
| 512 | return KEY_NOT_FOUND; |
| 513 | } |
| 514 | filepath8 = android::String8::format("%s/%s", getUserState(userId)->getUserDirName(), |
| 515 | filename8.string()); |
| 516 | if (!hasGrant(filepath8.string(), uid)) { |
| 517 | return responseCode; |
| 518 | } |
| 519 | |
| 520 | // It is a granted key. Try to load it. |
| 521 | return get(filepath8.string(), keyBlob, type, userId); |
| 522 | } |
| 523 | |
| 524 | UserState* KeyStore::getUserState(uid_t userId) { |
| 525 | for (android::Vector<UserState*>::iterator it(mMasterKeys.begin()); it != mMasterKeys.end(); |
| 526 | it++) { |
| 527 | UserState* state = *it; |
| 528 | if (state->getUserId() == userId) { |
| 529 | return state; |
| 530 | } |
| 531 | } |
| 532 | |
| 533 | UserState* userState = new UserState(userId); |
| 534 | if (!userState->initialize()) { |
| 535 | /* There's not much we can do if initialization fails. Trying to |
| 536 | * unlock the keystore for that user will fail as well, so any |
| 537 | * subsequent request for this user will just return SYSTEM_ERROR. |
| 538 | */ |
| 539 | ALOGE("User initialization failed for %u; subsuquent operations will fail", userId); |
| 540 | } |
| 541 | mMasterKeys.add(userState); |
| 542 | return userState; |
| 543 | } |
| 544 | |
| 545 | UserState* KeyStore::getUserStateByUid(uid_t uid) { |
| 546 | uid_t userId = get_user_id(uid); |
| 547 | return getUserState(userId); |
| 548 | } |
| 549 | |
| 550 | const UserState* KeyStore::getUserState(uid_t userId) const { |
| 551 | for (android::Vector<UserState*>::const_iterator it(mMasterKeys.begin()); |
| 552 | it != mMasterKeys.end(); it++) { |
| 553 | UserState* state = *it; |
| 554 | if (state->getUserId() == userId) { |
| 555 | return state; |
| 556 | } |
| 557 | } |
| 558 | |
| 559 | return NULL; |
| 560 | } |
| 561 | |
| 562 | const UserState* KeyStore::getUserStateByUid(uid_t uid) const { |
| 563 | uid_t userId = get_user_id(uid); |
| 564 | return getUserState(userId); |
| 565 | } |
| 566 | |
| 567 | const grant_t* KeyStore::getGrant(const char* filename, uid_t uid) const { |
| 568 | for (android::Vector<grant_t*>::const_iterator it(mGrants.begin()); it != mGrants.end(); it++) { |
| 569 | grant_t* grant = *it; |
| 570 | if (grant->uid == uid && |
| 571 | !strcmp(reinterpret_cast<const char*>(grant->filename), filename)) { |
| 572 | return grant; |
| 573 | } |
| 574 | } |
| 575 | return NULL; |
| 576 | } |
| 577 | |
| 578 | bool KeyStore::upgradeBlob(const char* filename, Blob* blob, const uint8_t oldVersion, |
| 579 | const BlobType type, uid_t uid) { |
| 580 | bool updated = false; |
| 581 | uint8_t version = oldVersion; |
| 582 | |
| 583 | /* From V0 -> V1: All old types were unknown */ |
| 584 | if (version == 0) { |
| 585 | ALOGV("upgrading to version 1 and setting type %d", type); |
| 586 | |
| 587 | blob->setType(type); |
| 588 | if (type == TYPE_KEY_PAIR) { |
| 589 | importBlobAsKey(blob, filename, uid); |
| 590 | } |
| 591 | version = 1; |
| 592 | updated = true; |
| 593 | } |
| 594 | |
| 595 | /* From V1 -> V2: All old keys were encrypted */ |
| 596 | if (version == 1) { |
| 597 | ALOGV("upgrading to version 2"); |
| 598 | |
| 599 | blob->setEncrypted(true); |
| 600 | version = 2; |
| 601 | updated = true; |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 602 | } |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 603 | |
| 604 | /* |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 605 | * If we've updated, set the key blob to the right version |
| 606 | * and write it. |
Kenny Root | 07438c8 | 2012-11-02 15:41:02 -0700 | [diff] [blame] | 607 | */ |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 608 | if (updated) { |
| 609 | ALOGV("updated and writing file %s", filename); |
| 610 | blob->setVersion(version); |
| 611 | } |
Kenny Root | 70e3a86 | 2012-02-15 17:20:23 -0800 | [diff] [blame] | 612 | |
Shawn Willden | 6507c27 | 2016-01-05 22:51:48 -0700 | [diff] [blame^] | 613 | return updated; |
| 614 | } |
| 615 | |
| 616 | struct BIO_Delete { |
| 617 | void operator()(BIO* p) const { BIO_free(p); } |
| 618 | }; |
| 619 | typedef UniquePtr<BIO, BIO_Delete> Unique_BIO; |
| 620 | |
| 621 | ResponseCode KeyStore::importBlobAsKey(Blob* blob, const char* filename, uid_t uid) { |
| 622 | // We won't even write to the blob directly with this BIO, so const_cast is okay. |
| 623 | Unique_BIO b(BIO_new_mem_buf(const_cast<uint8_t*>(blob->getValue()), blob->getLength())); |
| 624 | if (b.get() == NULL) { |
| 625 | ALOGE("Problem instantiating BIO"); |
| 626 | return SYSTEM_ERROR; |
| 627 | } |
| 628 | |
| 629 | Unique_EVP_PKEY pkey(PEM_read_bio_PrivateKey(b.get(), NULL, NULL, NULL)); |
| 630 | if (pkey.get() == NULL) { |
| 631 | ALOGE("Couldn't read old PEM file"); |
| 632 | return SYSTEM_ERROR; |
| 633 | } |
| 634 | |
| 635 | Unique_PKCS8_PRIV_KEY_INFO pkcs8(EVP_PKEY2PKCS8(pkey.get())); |
| 636 | int len = i2d_PKCS8_PRIV_KEY_INFO(pkcs8.get(), NULL); |
| 637 | if (len < 0) { |
| 638 | ALOGE("Couldn't measure PKCS#8 length"); |
| 639 | return SYSTEM_ERROR; |
| 640 | } |
| 641 | |
| 642 | UniquePtr<unsigned char[]> pkcs8key(new unsigned char[len]); |
| 643 | uint8_t* tmp = pkcs8key.get(); |
| 644 | if (i2d_PKCS8_PRIV_KEY_INFO(pkcs8.get(), &tmp) != len) { |
| 645 | ALOGE("Couldn't convert to PKCS#8"); |
| 646 | return SYSTEM_ERROR; |
| 647 | } |
| 648 | |
| 649 | ResponseCode rc = importKey(pkcs8key.get(), len, filename, get_user_id(uid), |
| 650 | blob->isEncrypted() ? KEYSTORE_FLAG_ENCRYPTED : KEYSTORE_FLAG_NONE); |
| 651 | if (rc != NO_ERROR) { |
| 652 | return rc; |
| 653 | } |
| 654 | |
| 655 | return get(filename, blob, TYPE_KEY_PAIR, uid); |
| 656 | } |
| 657 | |
| 658 | void KeyStore::readMetaData() { |
| 659 | int in = TEMP_FAILURE_RETRY(open(sMetaDataFile, O_RDONLY)); |
| 660 | if (in < 0) { |
| 661 | return; |
| 662 | } |
| 663 | size_t fileLength = readFully(in, (uint8_t*)&mMetaData, sizeof(mMetaData)); |
| 664 | if (fileLength != sizeof(mMetaData)) { |
| 665 | ALOGI("Metadata file is %zd bytes (%zd experted); upgrade?", fileLength, sizeof(mMetaData)); |
| 666 | } |
| 667 | close(in); |
| 668 | } |
| 669 | |
| 670 | void KeyStore::writeMetaData() { |
| 671 | const char* tmpFileName = ".metadata.tmp"; |
| 672 | int out = |
| 673 | TEMP_FAILURE_RETRY(open(tmpFileName, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR)); |
| 674 | if (out < 0) { |
| 675 | ALOGE("couldn't write metadata file: %s", strerror(errno)); |
| 676 | return; |
| 677 | } |
| 678 | size_t fileLength = writeFully(out, (uint8_t*)&mMetaData, sizeof(mMetaData)); |
| 679 | if (fileLength != sizeof(mMetaData)) { |
| 680 | ALOGI("Could only write %zd bytes to metadata file (%zd expected)", fileLength, |
| 681 | sizeof(mMetaData)); |
| 682 | } |
| 683 | close(out); |
| 684 | rename(tmpFileName, sMetaDataFile); |
| 685 | } |
| 686 | |
| 687 | bool KeyStore::upgradeKeystore() { |
| 688 | bool upgraded = false; |
| 689 | |
| 690 | if (mMetaData.version == 0) { |
| 691 | UserState* userState = getUserStateByUid(0); |
| 692 | |
| 693 | // Initialize first so the directory is made. |
| 694 | userState->initialize(); |
| 695 | |
| 696 | // Migrate the old .masterkey file to user 0. |
| 697 | if (access(sOldMasterKey, R_OK) == 0) { |
| 698 | if (rename(sOldMasterKey, userState->getMasterKeyFileName()) < 0) { |
| 699 | ALOGE("couldn't migrate old masterkey: %s", strerror(errno)); |
| 700 | return false; |
| 701 | } |
| 702 | } |
| 703 | |
| 704 | // Initialize again in case we had a key. |
| 705 | userState->initialize(); |
| 706 | |
| 707 | // Try to migrate existing keys. |
| 708 | DIR* dir = opendir("."); |
| 709 | if (!dir) { |
| 710 | // Give up now; maybe we can upgrade later. |
| 711 | ALOGE("couldn't open keystore's directory; something is wrong"); |
| 712 | return false; |
| 713 | } |
| 714 | |
| 715 | struct dirent* file; |
| 716 | while ((file = readdir(dir)) != NULL) { |
| 717 | // We only care about files. |
| 718 | if (file->d_type != DT_REG) { |
| 719 | continue; |
| 720 | } |
| 721 | |
| 722 | // Skip anything that starts with a "." |
| 723 | if (file->d_name[0] == '.') { |
| 724 | continue; |
| 725 | } |
| 726 | |
| 727 | // Find the current file's user. |
| 728 | char* end; |
| 729 | unsigned long thisUid = strtoul(file->d_name, &end, 10); |
| 730 | if (end[0] != '_' || end[1] == 0) { |
| 731 | continue; |
| 732 | } |
| 733 | UserState* otherUser = getUserStateByUid(thisUid); |
| 734 | if (otherUser->getUserId() != 0) { |
| 735 | unlinkat(dirfd(dir), file->d_name, 0); |
| 736 | } |
| 737 | |
| 738 | // Rename the file into user directory. |
| 739 | DIR* otherdir = opendir(otherUser->getUserDirName()); |
| 740 | if (otherdir == NULL) { |
| 741 | ALOGW("couldn't open user directory for rename"); |
| 742 | continue; |
| 743 | } |
| 744 | if (renameat(dirfd(dir), file->d_name, dirfd(otherdir), file->d_name) < 0) { |
| 745 | ALOGW("couldn't rename blob: %s: %s", file->d_name, strerror(errno)); |
| 746 | } |
| 747 | closedir(otherdir); |
| 748 | } |
| 749 | closedir(dir); |
| 750 | |
| 751 | mMetaData.version = 1; |
| 752 | upgraded = true; |
| 753 | } |
| 754 | |
| 755 | return upgraded; |
Kenny Root | a91203b | 2012-02-15 15:00:46 -0800 | [diff] [blame] | 756 | } |