1 /* 2 * Copyright (C) 2016 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 17 #include "KeyStorage.h" 18 19 #include "Keymaster.h" 20 #include "ScryptParameters.h" 21 #include "Utils.h" 22 23 #include <vector> 24 25 #include <errno.h> 26 #include <stdio.h> 27 #include <sys/stat.h> 28 #include <sys/types.h> 29 #include <sys/wait.h> 30 #include <unistd.h> 31 32 #include <openssl/err.h> 33 #include <openssl/evp.h> 34 #include <openssl/sha.h> 35 36 #include <android-base/file.h> 37 #include <android-base/logging.h> 38 #include <android-base/unique_fd.h> 39 40 #include <cutils/properties.h> 41 42 #include <hardware/hw_auth_token.h> 43 44 #include <keystore/authorization_set.h> 45 #include <keystore/keystore_hidl_support.h> 46 47 extern "C" { 48 49 #include "crypto_scrypt.h" 50 } 51 52 namespace android { 53 namespace vold { 54 using namespace keystore; 55 56 const KeyAuthentication kEmptyAuthentication{"", ""}; 57 58 static constexpr size_t AES_KEY_BYTES = 32; 59 static constexpr size_t GCM_NONCE_BYTES = 12; 60 static constexpr size_t GCM_MAC_BYTES = 16; 61 static constexpr size_t SALT_BYTES = 1 << 4; 62 static constexpr size_t SECDISCARDABLE_BYTES = 1 << 14; 63 static constexpr size_t STRETCHED_BYTES = 1 << 6; 64 65 static constexpr uint32_t AUTH_TIMEOUT = 30; // Seconds 66 67 static const char* kCurrentVersion = "1"; 68 static const char* kRmPath = "/system/bin/rm"; 69 static const char* kSecdiscardPath = "/system/bin/secdiscard"; 70 static const char* kStretch_none = "none"; 71 static const char* kStretch_nopassword = "nopassword"; 72 static const std::string kStretchPrefix_scrypt = "scrypt "; 73 static const char* kHashPrefix_secdiscardable = "Android secdiscardable SHA512"; 74 static const char* kHashPrefix_keygen = "Android key wrapping key generation SHA512"; 75 static const char* kFn_encrypted_key = "encrypted_key"; 76 static const char* kFn_keymaster_key_blob = "keymaster_key_blob"; 77 static const char* kFn_keymaster_key_blob_upgraded = "keymaster_key_blob_upgraded"; 78 static const char* kFn_salt = "salt"; 79 static const char* kFn_secdiscardable = "secdiscardable"; 80 static const char* kFn_stretching = "stretching"; 81 static const char* kFn_version = "version"; 82 83 static bool checkSize(const std::string& kind, size_t actual, size_t expected) { 84 if (actual != expected) { 85 LOG(ERROR) << "Wrong number of bytes in " << kind << ", expected " << expected << " got " 86 << actual; 87 return false; 88 } 89 return true; 90 } 91 92 static std::string hashWithPrefix(char const* prefix, const std::string& tohash) { 93 SHA512_CTX c; 94 95 SHA512_Init(&c); 96 // Personalise the hashing by introducing a fixed prefix. 97 // Hashing applications should use personalization except when there is a 98 // specific reason not to; see section 4.11 of https://www.schneier.com/skein1.3.pdf 99 std::string hashingPrefix = prefix; 100 hashingPrefix.resize(SHA512_CBLOCK); 101 SHA512_Update(&c, hashingPrefix.data(), hashingPrefix.size()); 102 SHA512_Update(&c, tohash.data(), tohash.size()); 103 std::string res(SHA512_DIGEST_LENGTH, '\0'); 104 SHA512_Final(reinterpret_cast<uint8_t*>(&res[0]), &c); 105 return res; 106 } 107 108 static bool generateKeymasterKey(Keymaster& keymaster, const KeyAuthentication& auth, 109 const std::string& appId, std::string* key) { 110 auto paramBuilder = AuthorizationSetBuilder() 111 .AesEncryptionKey(AES_KEY_BYTES * 8) 112 .Authorization(TAG_BLOCK_MODE, BlockMode::GCM) 113 .Authorization(TAG_MIN_MAC_LENGTH, GCM_MAC_BYTES * 8) 114 .Authorization(TAG_PADDING, PaddingMode::NONE) 115 .Authorization(TAG_APPLICATION_ID, blob2hidlVec(appId)); 116 if (auth.token.empty()) { 117 LOG(DEBUG) << "Creating key that doesn't need auth token"; 118 paramBuilder.Authorization(TAG_NO_AUTH_REQUIRED); 119 } else { 120 LOG(DEBUG) << "Auth token required for key"; 121 if (auth.token.size() != sizeof(hw_auth_token_t)) { 122 LOG(ERROR) << "Auth token should be " << sizeof(hw_auth_token_t) << " bytes, was " 123 << auth.token.size() << " bytes"; 124 return false; 125 } 126 const hw_auth_token_t* at = reinterpret_cast<const hw_auth_token_t*>(auth.token.data()); 127 paramBuilder.Authorization(TAG_USER_SECURE_ID, at->user_id); 128 paramBuilder.Authorization(TAG_USER_AUTH_TYPE, HardwareAuthenticatorType::PASSWORD); 129 paramBuilder.Authorization(TAG_AUTH_TIMEOUT, AUTH_TIMEOUT); 130 } 131 return keymaster.generateKey(paramBuilder, key); 132 } 133 134 static AuthorizationSet beginParams(const KeyAuthentication& auth, 135 const std::string& appId) { 136 auto paramBuilder = AuthorizationSetBuilder() 137 .Authorization(TAG_BLOCK_MODE, BlockMode::GCM) 138 .Authorization(TAG_MAC_LENGTH, GCM_MAC_BYTES * 8) 139 .Authorization(TAG_PADDING, PaddingMode::NONE) 140 .Authorization(TAG_APPLICATION_ID, blob2hidlVec(appId)); 141 if (!auth.token.empty()) { 142 LOG(DEBUG) << "Supplying auth token to Keymaster"; 143 paramBuilder.Authorization(TAG_AUTH_TOKEN, blob2hidlVec(auth.token)); 144 } 145 return paramBuilder; 146 } 147 148 static bool readFileToString(const std::string& filename, std::string* result) { 149 if (!android::base::ReadFileToString(filename, result)) { 150 PLOG(ERROR) << "Failed to read from " << filename; 151 return false; 152 } 153 return true; 154 } 155 156 static bool writeStringToFile(const std::string& payload, const std::string& filename) { 157 android::base::unique_fd fd(TEMP_FAILURE_RETRY( 158 open(filename.c_str(), O_WRONLY | O_CREAT | O_NOFOLLOW | O_TRUNC | O_CLOEXEC, 0666))); 159 if (fd == -1) { 160 PLOG(ERROR) << "Failed to open " << filename; 161 return false; 162 } 163 if (!android::base::WriteStringToFd(payload, fd)) { 164 PLOG(ERROR) << "Failed to write to " << filename; 165 unlink(filename.c_str()); 166 return false; 167 } 168 // fsync as close won't guarantee flush data 169 // see close(2), fsync(2) and b/68901441 170 if (fsync(fd) == -1) { 171 if (errno == EROFS || errno == EINVAL) { 172 PLOG(WARNING) << "Skip fsync " << filename 173 << " on a file system does not support synchronization"; 174 } else { 175 PLOG(ERROR) << "Failed to fsync " << filename; 176 unlink(filename.c_str()); 177 return false; 178 } 179 } 180 return true; 181 } 182 183 static KeymasterOperation begin(Keymaster& keymaster, const std::string& dir, 184 KeyPurpose purpose, 185 const AuthorizationSet &keyParams, 186 const AuthorizationSet &opParams, 187 AuthorizationSet* outParams) { 188 auto kmKeyPath = dir + "/" + kFn_keymaster_key_blob; 189 std::string kmKey; 190 if (!readFileToString(kmKeyPath, &kmKey)) return KeymasterOperation(); 191 AuthorizationSet inParams(keyParams); 192 inParams.append(opParams.begin(), opParams.end()); 193 for (;;) { 194 auto opHandle = keymaster.begin(purpose, kmKey, inParams, outParams); 195 if (opHandle) { 196 return opHandle; 197 } 198 if (opHandle.errorCode() != ErrorCode::KEY_REQUIRES_UPGRADE) return opHandle; 199 LOG(DEBUG) << "Upgrading key: " << dir; 200 std::string newKey; 201 if (!keymaster.upgradeKey(kmKey, keyParams, &newKey)) return KeymasterOperation(); 202 auto newKeyPath = dir + "/" + kFn_keymaster_key_blob_upgraded; 203 if (!writeStringToFile(newKey, newKeyPath)) return KeymasterOperation(); 204 if (rename(newKeyPath.c_str(), kmKeyPath.c_str()) != 0) { 205 PLOG(ERROR) << "Unable to move upgraded key to location: " << kmKeyPath; 206 return KeymasterOperation(); 207 } 208 if (!keymaster.deleteKey(kmKey)) { 209 LOG(ERROR) << "Key deletion failed during upgrade, continuing anyway: " << dir; 210 } 211 kmKey = newKey; 212 LOG(INFO) << "Key upgraded: " << dir; 213 } 214 } 215 216 static bool encryptWithKeymasterKey(Keymaster& keymaster, const std::string& dir, 217 const AuthorizationSet &keyParams, 218 const KeyBuffer& message, std::string* ciphertext) { 219 AuthorizationSet opParams; 220 AuthorizationSet outParams; 221 auto opHandle = begin(keymaster, dir, KeyPurpose::ENCRYPT, keyParams, opParams, &outParams); 222 if (!opHandle) return false; 223 auto nonceBlob = outParams.GetTagValue(TAG_NONCE); 224 if (!nonceBlob.isOk()) { 225 LOG(ERROR) << "GCM encryption but no nonce generated"; 226 return false; 227 } 228 // nonceBlob here is just a pointer into existing data, must not be freed 229 std::string nonce(reinterpret_cast<const char*>(&nonceBlob.value()[0]), nonceBlob.value().size()); 230 if (!checkSize("nonce", nonce.size(), GCM_NONCE_BYTES)) return false; 231 std::string body; 232 if (!opHandle.updateCompletely(message, &body)) return false; 233 234 std::string mac; 235 if (!opHandle.finish(&mac)) return false; 236 if (!checkSize("mac", mac.size(), GCM_MAC_BYTES)) return false; 237 *ciphertext = nonce + body + mac; 238 return true; 239 } 240 241 static bool decryptWithKeymasterKey(Keymaster& keymaster, const std::string& dir, 242 const AuthorizationSet &keyParams, 243 const std::string& ciphertext, KeyBuffer* message) { 244 auto nonce = ciphertext.substr(0, GCM_NONCE_BYTES); 245 auto bodyAndMac = ciphertext.substr(GCM_NONCE_BYTES); 246 auto opParams = AuthorizationSetBuilder() 247 .Authorization(TAG_NONCE, blob2hidlVec(nonce)); 248 auto opHandle = begin(keymaster, dir, KeyPurpose::DECRYPT, keyParams, opParams, nullptr); 249 if (!opHandle) return false; 250 if (!opHandle.updateCompletely(bodyAndMac, message)) return false; 251 if (!opHandle.finish(nullptr)) return false; 252 return true; 253 } 254 255 static std::string getStretching(const KeyAuthentication& auth) { 256 if (!auth.usesKeymaster()) { 257 return kStretch_none; 258 } else if (auth.secret.empty()) { 259 return kStretch_nopassword; 260 } else { 261 char paramstr[PROPERTY_VALUE_MAX]; 262 263 property_get(SCRYPT_PROP, paramstr, SCRYPT_DEFAULTS); 264 return std::string() + kStretchPrefix_scrypt + paramstr; 265 } 266 } 267 268 static bool stretchingNeedsSalt(const std::string& stretching) { 269 return stretching != kStretch_nopassword && stretching != kStretch_none; 270 } 271 272 static bool stretchSecret(const std::string& stretching, const std::string& secret, 273 const std::string& salt, std::string* stretched) { 274 if (stretching == kStretch_nopassword) { 275 if (!secret.empty()) { 276 LOG(WARNING) << "Password present but stretching is nopassword"; 277 // Continue anyway 278 } 279 stretched->clear(); 280 } else if (stretching == kStretch_none) { 281 *stretched = secret; 282 } else if (std::equal(kStretchPrefix_scrypt.begin(), kStretchPrefix_scrypt.end(), 283 stretching.begin())) { 284 int Nf, rf, pf; 285 if (!parse_scrypt_parameters(stretching.substr(kStretchPrefix_scrypt.size()).c_str(), &Nf, 286 &rf, &pf)) { 287 LOG(ERROR) << "Unable to parse scrypt params in stretching: " << stretching; 288 return false; 289 } 290 stretched->assign(STRETCHED_BYTES, '\0'); 291 if (crypto_scrypt(reinterpret_cast<const uint8_t*>(secret.data()), secret.size(), 292 reinterpret_cast<const uint8_t*>(salt.data()), salt.size(), 293 1 << Nf, 1 << rf, 1 << pf, 294 reinterpret_cast<uint8_t*>(&(*stretched)[0]), stretched->size()) != 0) { 295 LOG(ERROR) << "scrypt failed with params: " << stretching; 296 return false; 297 } 298 } else { 299 LOG(ERROR) << "Unknown stretching type: " << stretching; 300 return false; 301 } 302 return true; 303 } 304 305 static bool generateAppId(const KeyAuthentication& auth, const std::string& stretching, 306 const std::string& salt, const std::string& secdiscardable, 307 std::string* appId) { 308 std::string stretched; 309 if (!stretchSecret(stretching, auth.secret, salt, &stretched)) return false; 310 *appId = hashWithPrefix(kHashPrefix_secdiscardable, secdiscardable) + stretched; 311 return true; 312 } 313 314 static bool readRandomBytesOrLog(size_t count, std::string* out) { 315 auto status = ReadRandomBytes(count, *out); 316 if (status != OK) { 317 LOG(ERROR) << "Random read failed with status: " << status; 318 return false; 319 } 320 return true; 321 } 322 323 static void logOpensslError() { 324 LOG(ERROR) << "Openssl error: " << ERR_get_error(); 325 } 326 327 static bool encryptWithoutKeymaster(const std::string& preKey, 328 const KeyBuffer& plaintext, std::string* ciphertext) { 329 auto key = hashWithPrefix(kHashPrefix_keygen, preKey); 330 key.resize(AES_KEY_BYTES); 331 if (!readRandomBytesOrLog(GCM_NONCE_BYTES, ciphertext)) return false; 332 auto ctx = std::unique_ptr<EVP_CIPHER_CTX, decltype(&::EVP_CIPHER_CTX_free)>( 333 EVP_CIPHER_CTX_new(), EVP_CIPHER_CTX_free); 334 if (!ctx) { 335 logOpensslError(); 336 return false; 337 } 338 if (1 != EVP_EncryptInit_ex(ctx.get(), EVP_aes_256_gcm(), NULL, 339 reinterpret_cast<const uint8_t*>(key.data()), 340 reinterpret_cast<const uint8_t*>(ciphertext->data()))) { 341 logOpensslError(); 342 return false; 343 } 344 ciphertext->resize(GCM_NONCE_BYTES + plaintext.size() + GCM_MAC_BYTES); 345 int outlen; 346 if (1 != EVP_EncryptUpdate(ctx.get(), 347 reinterpret_cast<uint8_t*>(&(*ciphertext)[0] + GCM_NONCE_BYTES), &outlen, 348 reinterpret_cast<const uint8_t*>(plaintext.data()), plaintext.size())) { 349 logOpensslError(); 350 return false; 351 } 352 if (outlen != static_cast<int>(plaintext.size())) { 353 LOG(ERROR) << "GCM ciphertext length should be " << plaintext.size() << " was " << outlen; 354 return false; 355 } 356 if (1 != EVP_EncryptFinal_ex(ctx.get(), 357 reinterpret_cast<uint8_t*>(&(*ciphertext)[0] + GCM_NONCE_BYTES + plaintext.size()), &outlen)) { 358 logOpensslError(); 359 return false; 360 } 361 if (outlen != 0) { 362 LOG(ERROR) << "GCM EncryptFinal should be 0, was " << outlen; 363 return false; 364 } 365 if (1 != EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_GCM_GET_TAG, GCM_MAC_BYTES, 366 reinterpret_cast<uint8_t*>(&(*ciphertext)[0] + GCM_NONCE_BYTES + plaintext.size()))) { 367 logOpensslError(); 368 return false; 369 } 370 return true; 371 } 372 373 static bool decryptWithoutKeymaster(const std::string& preKey, 374 const std::string& ciphertext, KeyBuffer* plaintext) { 375 if (ciphertext.size() < GCM_NONCE_BYTES + GCM_MAC_BYTES) { 376 LOG(ERROR) << "GCM ciphertext too small: " << ciphertext.size(); 377 return false; 378 } 379 auto key = hashWithPrefix(kHashPrefix_keygen, preKey); 380 key.resize(AES_KEY_BYTES); 381 auto ctx = std::unique_ptr<EVP_CIPHER_CTX, decltype(&::EVP_CIPHER_CTX_free)>( 382 EVP_CIPHER_CTX_new(), EVP_CIPHER_CTX_free); 383 if (!ctx) { 384 logOpensslError(); 385 return false; 386 } 387 if (1 != EVP_DecryptInit_ex(ctx.get(), EVP_aes_256_gcm(), NULL, 388 reinterpret_cast<const uint8_t*>(key.data()), 389 reinterpret_cast<const uint8_t*>(ciphertext.data()))) { 390 logOpensslError(); 391 return false; 392 } 393 *plaintext = KeyBuffer(ciphertext.size() - GCM_NONCE_BYTES - GCM_MAC_BYTES); 394 int outlen; 395 if (1 != EVP_DecryptUpdate(ctx.get(), 396 reinterpret_cast<uint8_t*>(&(*plaintext)[0]), &outlen, 397 reinterpret_cast<const uint8_t*>(ciphertext.data() + GCM_NONCE_BYTES), plaintext->size())) { 398 logOpensslError(); 399 return false; 400 } 401 if (outlen != static_cast<int>(plaintext->size())) { 402 LOG(ERROR) << "GCM plaintext length should be " << plaintext->size() << " was " << outlen; 403 return false; 404 } 405 if (1 != EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_GCM_SET_TAG, GCM_MAC_BYTES, 406 const_cast<void *>( 407 reinterpret_cast<const void*>(ciphertext.data() + GCM_NONCE_BYTES + plaintext->size())))) { 408 logOpensslError(); 409 return false; 410 } 411 if (1 != EVP_DecryptFinal_ex(ctx.get(), 412 reinterpret_cast<uint8_t*>(&(*plaintext)[0] + plaintext->size()), &outlen)) { 413 logOpensslError(); 414 return false; 415 } 416 if (outlen != 0) { 417 LOG(ERROR) << "GCM EncryptFinal should be 0, was " << outlen; 418 return false; 419 } 420 return true; 421 } 422 423 bool pathExists(const std::string& path) { 424 return access(path.c_str(), F_OK) == 0; 425 } 426 427 bool storeKey(const std::string& dir, const KeyAuthentication& auth, const KeyBuffer& key) { 428 if (TEMP_FAILURE_RETRY(mkdir(dir.c_str(), 0700)) == -1) { 429 PLOG(ERROR) << "key mkdir " << dir; 430 return false; 431 } 432 if (!writeStringToFile(kCurrentVersion, dir + "/" + kFn_version)) return false; 433 std::string secdiscardable; 434 if (!readRandomBytesOrLog(SECDISCARDABLE_BYTES, &secdiscardable)) return false; 435 if (!writeStringToFile(secdiscardable, dir + "/" + kFn_secdiscardable)) return false; 436 std::string stretching = getStretching(auth); 437 if (!writeStringToFile(stretching, dir + "/" + kFn_stretching)) return false; 438 std::string salt; 439 if (stretchingNeedsSalt(stretching)) { 440 if (ReadRandomBytes(SALT_BYTES, salt) != OK) { 441 LOG(ERROR) << "Random read failed"; 442 return false; 443 } 444 if (!writeStringToFile(salt, dir + "/" + kFn_salt)) return false; 445 } 446 std::string appId; 447 if (!generateAppId(auth, stretching, salt, secdiscardable, &appId)) return false; 448 std::string encryptedKey; 449 if (auth.usesKeymaster()) { 450 Keymaster keymaster; 451 if (!keymaster) return false; 452 std::string kmKey; 453 if (!generateKeymasterKey(keymaster, auth, appId, &kmKey)) return false; 454 if (!writeStringToFile(kmKey, dir + "/" + kFn_keymaster_key_blob)) return false; 455 auto keyParams = beginParams(auth, appId); 456 if (!encryptWithKeymasterKey(keymaster, dir, keyParams, key, &encryptedKey)) return false; 457 } else { 458 if (!encryptWithoutKeymaster(appId, key, &encryptedKey)) return false; 459 } 460 if (!writeStringToFile(encryptedKey, dir + "/" + kFn_encrypted_key)) return false; 461 return true; 462 } 463 464 bool storeKeyAtomically(const std::string& key_path, const std::string& tmp_path, 465 const KeyAuthentication& auth, const KeyBuffer& key) { 466 if (pathExists(key_path)) { 467 LOG(ERROR) << "Already exists, cannot create key at: " << key_path; 468 return false; 469 } 470 if (pathExists(tmp_path)) { 471 LOG(DEBUG) << "Already exists, destroying: " << tmp_path; 472 destroyKey(tmp_path); // May be partially created so ignore errors 473 } 474 if (!storeKey(tmp_path, auth, key)) return false; 475 if (rename(tmp_path.c_str(), key_path.c_str()) != 0) { 476 PLOG(ERROR) << "Unable to move new key to location: " << key_path; 477 return false; 478 } 479 LOG(DEBUG) << "Created key: " << key_path; 480 return true; 481 } 482 483 bool retrieveKey(const std::string& dir, const KeyAuthentication& auth, KeyBuffer* key) { 484 std::string version; 485 if (!readFileToString(dir + "/" + kFn_version, &version)) return false; 486 if (version != kCurrentVersion) { 487 LOG(ERROR) << "Version mismatch, expected " << kCurrentVersion << " got " << version; 488 return false; 489 } 490 std::string secdiscardable; 491 if (!readFileToString(dir + "/" + kFn_secdiscardable, &secdiscardable)) return false; 492 std::string stretching; 493 if (!readFileToString(dir + "/" + kFn_stretching, &stretching)) return false; 494 std::string salt; 495 if (stretchingNeedsSalt(stretching)) { 496 if (!readFileToString(dir + "/" + kFn_salt, &salt)) return false; 497 } 498 std::string appId; 499 if (!generateAppId(auth, stretching, salt, secdiscardable, &appId)) return false; 500 std::string encryptedMessage; 501 if (!readFileToString(dir + "/" + kFn_encrypted_key, &encryptedMessage)) return false; 502 if (auth.usesKeymaster()) { 503 Keymaster keymaster; 504 if (!keymaster) return false; 505 auto keyParams = beginParams(auth, appId); 506 if (!decryptWithKeymasterKey(keymaster, dir, keyParams, encryptedMessage, key)) return false; 507 } else { 508 if (!decryptWithoutKeymaster(appId, encryptedMessage, key)) return false; 509 } 510 return true; 511 } 512 513 static bool deleteKey(const std::string& dir) { 514 std::string kmKey; 515 if (!readFileToString(dir + "/" + kFn_keymaster_key_blob, &kmKey)) return false; 516 Keymaster keymaster; 517 if (!keymaster) return false; 518 if (!keymaster.deleteKey(kmKey)) return false; 519 return true; 520 } 521 522 static bool runSecdiscard(const std::string& dir) { 523 if (ForkExecvp( 524 std::vector<std::string>{kSecdiscardPath, "--", 525 dir + "/" + kFn_encrypted_key, 526 dir + "/" + kFn_keymaster_key_blob, 527 dir + "/" + kFn_secdiscardable, 528 }) != 0) { 529 LOG(ERROR) << "secdiscard failed"; 530 return false; 531 } 532 return true; 533 } 534 535 bool runSecdiscardSingle(const std::string& file) { 536 if (ForkExecvp( 537 std::vector<std::string>{kSecdiscardPath, "--", 538 file}) != 0) { 539 LOG(ERROR) << "secdiscard failed"; 540 return false; 541 } 542 return true; 543 } 544 545 static bool recursiveDeleteKey(const std::string& dir) { 546 if (ForkExecvp(std::vector<std::string>{kRmPath, "-rf", dir}) != 0) { 547 LOG(ERROR) << "recursive delete failed"; 548 return false; 549 } 550 return true; 551 } 552 553 bool destroyKey(const std::string& dir) { 554 bool success = true; 555 // Try each thing, even if previous things failed. 556 success &= deleteKey(dir); 557 success &= runSecdiscard(dir); 558 success &= recursiveDeleteKey(dir); 559 return success; 560 } 561 562 } // namespace vold 563 } // namespace android 564
