| /* |
| * Copyright (C) 2016 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 "key_store_service.h" |
| |
| #include <fcntl.h> |
| #include <sys/stat.h> |
| |
| #include <sstream> |
| |
| #include <binder/IPCThreadState.h> |
| |
| #include <private/android_filesystem_config.h> |
| |
| #include <hardware/keymaster_defs.h> |
| |
| #include "defaults.h" |
| #include "keystore_utils.h" |
| |
| using keymaster::AuthorizationSet; |
| using keymaster::AuthorizationSetBuilder; |
| using keymaster::TAG_APPLICATION_DATA; |
| using keymaster::TAG_APPLICATION_ID; |
| |
| namespace android { |
| |
| const size_t MAX_OPERATIONS = 15; |
| |
| struct BIGNUM_Delete { |
| void operator()(BIGNUM* p) const { BN_free(p); } |
| }; |
| typedef UniquePtr<BIGNUM, BIGNUM_Delete> Unique_BIGNUM; |
| |
| struct Malloc_Delete { |
| void operator()(uint8_t* p) const { free(p); } |
| }; |
| |
| void KeyStoreService::binderDied(const wp<IBinder>& who) { |
| auto operations = mOperationMap.getOperationsForToken(who.unsafe_get()); |
| for (auto token : operations) { |
| abort(token); |
| } |
| } |
| |
| int32_t KeyStoreService::getState(int32_t userId) { |
| if (!checkBinderPermission(P_GET_STATE)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| return mKeyStore->getState(userId); |
| } |
| |
| int32_t KeyStoreService::get(const String16& name, int32_t uid, uint8_t** item, |
| size_t* itemLength) { |
| uid_t targetUid = getEffectiveUid(uid); |
| if (!checkBinderPermission(P_GET, targetUid)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| String8 name8(name); |
| Blob keyBlob; |
| |
| ResponseCode responseCode = mKeyStore->getKeyForName(&keyBlob, name8, targetUid, TYPE_GENERIC); |
| if (responseCode != ::NO_ERROR) { |
| *item = NULL; |
| *itemLength = 0; |
| return responseCode; |
| } |
| |
| *item = (uint8_t*)malloc(keyBlob.getLength()); |
| memcpy(*item, keyBlob.getValue(), keyBlob.getLength()); |
| *itemLength = keyBlob.getLength(); |
| |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::insert(const String16& name, const uint8_t* item, size_t itemLength, |
| int targetUid, int32_t flags) { |
| targetUid = getEffectiveUid(targetUid); |
| int32_t result = |
| checkBinderPermissionAndKeystoreState(P_INSERT, targetUid, flags & KEYSTORE_FLAG_ENCRYPTED); |
| if (result != ::NO_ERROR) { |
| return result; |
| } |
| |
| String8 name8(name); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, targetUid)); |
| |
| Blob keyBlob(item, itemLength, NULL, 0, ::TYPE_GENERIC); |
| keyBlob.setEncrypted(flags & KEYSTORE_FLAG_ENCRYPTED); |
| |
| return mKeyStore->put(filename.string(), &keyBlob, get_user_id(targetUid)); |
| } |
| |
| int32_t KeyStoreService::del(const String16& name, int targetUid) { |
| targetUid = getEffectiveUid(targetUid); |
| if (!checkBinderPermission(P_DELETE, targetUid)) { |
| return ::PERMISSION_DENIED; |
| } |
| String8 name8(name); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, targetUid)); |
| return mKeyStore->del(filename.string(), ::TYPE_ANY, get_user_id(targetUid)); |
| } |
| |
| int32_t KeyStoreService::exist(const String16& name, int targetUid) { |
| targetUid = getEffectiveUid(targetUid); |
| if (!checkBinderPermission(P_EXIST, targetUid)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| String8 name8(name); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, targetUid)); |
| |
| if (access(filename.string(), R_OK) == -1) { |
| return (errno != ENOENT) ? ::SYSTEM_ERROR : ::KEY_NOT_FOUND; |
| } |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::list(const String16& prefix, int targetUid, Vector<String16>* matches) { |
| targetUid = getEffectiveUid(targetUid); |
| if (!checkBinderPermission(P_LIST, targetUid)) { |
| return ::PERMISSION_DENIED; |
| } |
| const String8 prefix8(prefix); |
| String8 filename(mKeyStore->getKeyNameForUid(prefix8, targetUid)); |
| |
| if (mKeyStore->list(filename, matches, get_user_id(targetUid)) != ::NO_ERROR) { |
| return ::SYSTEM_ERROR; |
| } |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::reset() { |
| if (!checkBinderPermission(P_RESET)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| mKeyStore->resetUser(get_user_id(callingUid), false); |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::onUserPasswordChanged(int32_t userId, const String16& password) { |
| if (!checkBinderPermission(P_PASSWORD)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| const String8 password8(password); |
| // Flush the auth token table to prevent stale tokens from sticking |
| // around. |
| mAuthTokenTable.Clear(); |
| |
| if (password.size() == 0) { |
| ALOGI("Secure lockscreen for user %d removed, deleting encrypted entries", userId); |
| mKeyStore->resetUser(userId, true); |
| return ::NO_ERROR; |
| } else { |
| switch (mKeyStore->getState(userId)) { |
| case ::STATE_UNINITIALIZED: { |
| // generate master key, encrypt with password, write to file, |
| // initialize mMasterKey*. |
| return mKeyStore->initializeUser(password8, userId); |
| } |
| case ::STATE_NO_ERROR: { |
| // rewrite master key with new password. |
| return mKeyStore->writeMasterKey(password8, userId); |
| } |
| case ::STATE_LOCKED: { |
| ALOGE("Changing user %d's password while locked, clearing old encryption", userId); |
| mKeyStore->resetUser(userId, true); |
| return mKeyStore->initializeUser(password8, userId); |
| } |
| } |
| return ::SYSTEM_ERROR; |
| } |
| } |
| |
| int32_t KeyStoreService::onUserAdded(int32_t userId, int32_t parentId) { |
| if (!checkBinderPermission(P_USER_CHANGED)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| // Sanity check that the new user has an empty keystore. |
| if (!mKeyStore->isEmpty(userId)) { |
| ALOGW("New user %d's keystore not empty. Clearing old entries.", userId); |
| } |
| // Unconditionally clear the keystore, just to be safe. |
| mKeyStore->resetUser(userId, false); |
| if (parentId != -1) { |
| // This profile must share the same master key password as the parent profile. Because the |
| // password of the parent profile is not known here, the best we can do is copy the parent's |
| // master key and master key file. This makes this profile use the same master key as the |
| // parent profile, forever. |
| return mKeyStore->copyMasterKey(parentId, userId); |
| } else { |
| return ::NO_ERROR; |
| } |
| } |
| |
| int32_t KeyStoreService::onUserRemoved(int32_t userId) { |
| if (!checkBinderPermission(P_USER_CHANGED)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| mKeyStore->resetUser(userId, false); |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::lock(int32_t userId) { |
| if (!checkBinderPermission(P_LOCK)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| State state = mKeyStore->getState(userId); |
| if (state != ::STATE_NO_ERROR) { |
| ALOGD("calling lock in state: %d", state); |
| return state; |
| } |
| |
| mKeyStore->lock(userId); |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::unlock(int32_t userId, const String16& pw) { |
| if (!checkBinderPermission(P_UNLOCK)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| State state = mKeyStore->getState(userId); |
| if (state != ::STATE_LOCKED) { |
| switch (state) { |
| case ::STATE_NO_ERROR: |
| ALOGI("calling unlock when already unlocked, ignoring."); |
| break; |
| case ::STATE_UNINITIALIZED: |
| ALOGE("unlock called on uninitialized keystore."); |
| break; |
| default: |
| ALOGE("unlock called on keystore in unknown state: %d", state); |
| break; |
| } |
| return state; |
| } |
| |
| const String8 password8(pw); |
| // read master key, decrypt with password, initialize mMasterKey*. |
| return mKeyStore->readMasterKey(password8, userId); |
| } |
| |
| bool KeyStoreService::isEmpty(int32_t userId) { |
| if (!checkBinderPermission(P_IS_EMPTY)) { |
| return false; |
| } |
| |
| return mKeyStore->isEmpty(userId); |
| } |
| |
| int32_t KeyStoreService::generate(const String16& name, int32_t targetUid, int32_t keyType, |
| int32_t keySize, int32_t flags, Vector<sp<KeystoreArg>>* args) { |
| targetUid = getEffectiveUid(targetUid); |
| int32_t result = |
| checkBinderPermissionAndKeystoreState(P_INSERT, targetUid, flags & KEYSTORE_FLAG_ENCRYPTED); |
| if (result != ::NO_ERROR) { |
| return result; |
| } |
| |
| KeymasterArguments params; |
| add_legacy_key_authorizations(keyType, ¶ms.params); |
| |
| switch (keyType) { |
| case EVP_PKEY_EC: { |
| params.params.push_back(keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_EC)); |
| if (keySize == -1) { |
| keySize = EC_DEFAULT_KEY_SIZE; |
| } else if (keySize < EC_MIN_KEY_SIZE || keySize > EC_MAX_KEY_SIZE) { |
| ALOGI("invalid key size %d", keySize); |
| return ::SYSTEM_ERROR; |
| } |
| params.params.push_back(keymaster_param_int(KM_TAG_KEY_SIZE, keySize)); |
| break; |
| } |
| case EVP_PKEY_RSA: { |
| params.params.push_back(keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_RSA)); |
| if (keySize == -1) { |
| keySize = RSA_DEFAULT_KEY_SIZE; |
| } else if (keySize < RSA_MIN_KEY_SIZE || keySize > RSA_MAX_KEY_SIZE) { |
| ALOGI("invalid key size %d", keySize); |
| return ::SYSTEM_ERROR; |
| } |
| params.params.push_back(keymaster_param_int(KM_TAG_KEY_SIZE, keySize)); |
| unsigned long exponent = RSA_DEFAULT_EXPONENT; |
| if (args->size() > 1) { |
| ALOGI("invalid number of arguments: %zu", args->size()); |
| return ::SYSTEM_ERROR; |
| } else if (args->size() == 1) { |
| sp<KeystoreArg> expArg = args->itemAt(0); |
| if (expArg != NULL) { |
| Unique_BIGNUM pubExpBn(BN_bin2bn( |
| reinterpret_cast<const unsigned char*>(expArg->data()), expArg->size(), NULL)); |
| if (pubExpBn.get() == NULL) { |
| ALOGI("Could not convert public exponent to BN"); |
| return ::SYSTEM_ERROR; |
| } |
| exponent = BN_get_word(pubExpBn.get()); |
| if (exponent == 0xFFFFFFFFL) { |
| ALOGW("cannot represent public exponent as a long value"); |
| return ::SYSTEM_ERROR; |
| } |
| } else { |
| ALOGW("public exponent not read"); |
| return ::SYSTEM_ERROR; |
| } |
| } |
| params.params.push_back(keymaster_param_long(KM_TAG_RSA_PUBLIC_EXPONENT, exponent)); |
| break; |
| } |
| default: { |
| ALOGW("Unsupported key type %d", keyType); |
| return ::SYSTEM_ERROR; |
| } |
| } |
| |
| int32_t rc = generateKey(name, params, NULL, 0, targetUid, flags, |
| /*outCharacteristics*/ NULL); |
| if (rc != ::NO_ERROR) { |
| ALOGW("generate failed: %d", rc); |
| } |
| return translateResultToLegacyResult(rc); |
| } |
| |
| int32_t KeyStoreService::import(const String16& name, const uint8_t* data, size_t length, |
| int targetUid, int32_t flags) { |
| const uint8_t* ptr = data; |
| |
| Unique_PKCS8_PRIV_KEY_INFO pkcs8(d2i_PKCS8_PRIV_KEY_INFO(NULL, &ptr, length)); |
| if (!pkcs8.get()) { |
| return ::SYSTEM_ERROR; |
| } |
| Unique_EVP_PKEY pkey(EVP_PKCS82PKEY(pkcs8.get())); |
| if (!pkey.get()) { |
| return ::SYSTEM_ERROR; |
| } |
| int type = EVP_PKEY_type(pkey->type); |
| KeymasterArguments params; |
| add_legacy_key_authorizations(type, ¶ms.params); |
| switch (type) { |
| case EVP_PKEY_RSA: |
| params.params.push_back(keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_RSA)); |
| break; |
| case EVP_PKEY_EC: |
| params.params.push_back(keymaster_param_enum(KM_TAG_ALGORITHM, KM_ALGORITHM_EC)); |
| break; |
| default: |
| ALOGW("Unsupported key type %d", type); |
| return ::SYSTEM_ERROR; |
| } |
| int32_t rc = importKey(name, params, KM_KEY_FORMAT_PKCS8, data, length, targetUid, flags, |
| /*outCharacteristics*/ NULL); |
| if (rc != ::NO_ERROR) { |
| ALOGW("importKey failed: %d", rc); |
| } |
| return translateResultToLegacyResult(rc); |
| } |
| |
| int32_t KeyStoreService::sign(const String16& name, const uint8_t* data, size_t length, |
| uint8_t** out, size_t* outLength) { |
| if (!checkBinderPermission(P_SIGN)) { |
| return ::PERMISSION_DENIED; |
| } |
| return doLegacySignVerify(name, data, length, out, outLength, NULL, 0, KM_PURPOSE_SIGN); |
| } |
| |
| int32_t KeyStoreService::verify(const String16& name, const uint8_t* data, size_t dataLength, |
| const uint8_t* signature, size_t signatureLength) { |
| if (!checkBinderPermission(P_VERIFY)) { |
| return ::PERMISSION_DENIED; |
| } |
| return doLegacySignVerify(name, data, dataLength, NULL, NULL, signature, signatureLength, |
| KM_PURPOSE_VERIFY); |
| } |
| |
| /* |
| * TODO: The abstraction between things stored in hardware and regular blobs |
| * of data stored on the filesystem should be moved down to keystore itself. |
| * Unfortunately the Java code that calls this has naming conventions that it |
| * knows about. Ideally keystore shouldn't be used to store random blobs of |
| * data. |
| * |
| * Until that happens, it's necessary to have a separate "get_pubkey" and |
| * "del_key" since the Java code doesn't really communicate what it's |
| * intentions are. |
| */ |
| int32_t KeyStoreService::get_pubkey(const String16& name, uint8_t** pubkey, size_t* pubkeyLength) { |
| ExportResult result; |
| exportKey(name, KM_KEY_FORMAT_X509, NULL, NULL, UID_SELF, &result); |
| if (result.resultCode != ::NO_ERROR) { |
| ALOGW("export failed: %d", result.resultCode); |
| return translateResultToLegacyResult(result.resultCode); |
| } |
| |
| *pubkey = result.exportData.release(); |
| *pubkeyLength = result.dataLength; |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::grant(const String16& name, int32_t granteeUid) { |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| int32_t result = checkBinderPermissionAndKeystoreState(P_GRANT); |
| if (result != ::NO_ERROR) { |
| return result; |
| } |
| |
| String8 name8(name); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, callingUid)); |
| |
| if (access(filename.string(), R_OK) == -1) { |
| return (errno != ENOENT) ? ::SYSTEM_ERROR : ::KEY_NOT_FOUND; |
| } |
| |
| mKeyStore->addGrant(filename.string(), granteeUid); |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::ungrant(const String16& name, int32_t granteeUid) { |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| int32_t result = checkBinderPermissionAndKeystoreState(P_GRANT); |
| if (result != ::NO_ERROR) { |
| return result; |
| } |
| |
| String8 name8(name); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, callingUid)); |
| |
| if (access(filename.string(), R_OK) == -1) { |
| return (errno != ENOENT) ? ::SYSTEM_ERROR : ::KEY_NOT_FOUND; |
| } |
| |
| return mKeyStore->removeGrant(filename.string(), granteeUid) ? ::NO_ERROR : ::KEY_NOT_FOUND; |
| } |
| |
| int64_t KeyStoreService::getmtime(const String16& name, int32_t uid) { |
| uid_t targetUid = getEffectiveUid(uid); |
| if (!checkBinderPermission(P_GET, targetUid)) { |
| ALOGW("permission denied for %d: getmtime", targetUid); |
| return -1L; |
| } |
| |
| String8 name8(name); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, targetUid)); |
| |
| if (access(filename.string(), R_OK) == -1) { |
| ALOGW("could not access %s for getmtime", filename.string()); |
| return -1L; |
| } |
| |
| int fd = TEMP_FAILURE_RETRY(open(filename.string(), O_NOFOLLOW, O_RDONLY)); |
| if (fd < 0) { |
| ALOGW("could not open %s for getmtime", filename.string()); |
| return -1L; |
| } |
| |
| struct stat s; |
| int ret = fstat(fd, &s); |
| close(fd); |
| if (ret == -1) { |
| ALOGW("could not stat %s for getmtime", filename.string()); |
| return -1L; |
| } |
| |
| return static_cast<int64_t>(s.st_mtime); |
| } |
| |
| int32_t KeyStoreService::duplicate(const String16& srcKey, int32_t srcUid, const String16& destKey, |
| int32_t destUid) { |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| pid_t spid = IPCThreadState::self()->getCallingPid(); |
| if (!has_permission(callingUid, P_DUPLICATE, spid)) { |
| ALOGW("permission denied for %d: duplicate", callingUid); |
| return -1L; |
| } |
| |
| State state = mKeyStore->getState(get_user_id(callingUid)); |
| if (!isKeystoreUnlocked(state)) { |
| ALOGD("calling duplicate in state: %d", state); |
| return state; |
| } |
| |
| if (srcUid == -1 || static_cast<uid_t>(srcUid) == callingUid) { |
| srcUid = callingUid; |
| } else if (!is_granted_to(callingUid, srcUid)) { |
| ALOGD("migrate not granted from source: %d -> %d", callingUid, srcUid); |
| return ::PERMISSION_DENIED; |
| } |
| |
| if (destUid == -1) { |
| destUid = callingUid; |
| } |
| |
| if (srcUid != destUid) { |
| if (static_cast<uid_t>(srcUid) != callingUid) { |
| ALOGD("can only duplicate from caller to other or to same uid: " |
| "calling=%d, srcUid=%d, destUid=%d", |
| callingUid, srcUid, destUid); |
| return ::PERMISSION_DENIED; |
| } |
| |
| if (!is_granted_to(callingUid, destUid)) { |
| ALOGD("duplicate not granted to dest: %d -> %d", callingUid, destUid); |
| return ::PERMISSION_DENIED; |
| } |
| } |
| |
| String8 source8(srcKey); |
| String8 sourceFile(mKeyStore->getKeyNameForUidWithDir(source8, srcUid)); |
| |
| String8 target8(destKey); |
| String8 targetFile(mKeyStore->getKeyNameForUidWithDir(target8, destUid)); |
| |
| if (access(targetFile.string(), W_OK) != -1 || errno != ENOENT) { |
| ALOGD("destination already exists: %s", targetFile.string()); |
| return ::SYSTEM_ERROR; |
| } |
| |
| Blob keyBlob; |
| ResponseCode responseCode = |
| mKeyStore->get(sourceFile.string(), &keyBlob, TYPE_ANY, get_user_id(srcUid)); |
| if (responseCode != ::NO_ERROR) { |
| return responseCode; |
| } |
| |
| return mKeyStore->put(targetFile.string(), &keyBlob, get_user_id(destUid)); |
| } |
| |
| int32_t KeyStoreService::is_hardware_backed(const String16& keyType) { |
| return mKeyStore->isHardwareBacked(keyType) ? 1 : 0; |
| } |
| |
| int32_t KeyStoreService::clear_uid(int64_t targetUid64) { |
| uid_t targetUid = getEffectiveUid(targetUid64); |
| if (!checkBinderPermissionSelfOrSystem(P_CLEAR_UID, targetUid)) { |
| return ::PERMISSION_DENIED; |
| } |
| |
| String8 prefix = String8::format("%u_", targetUid); |
| Vector<String16> aliases; |
| if (mKeyStore->list(prefix, &aliases, get_user_id(targetUid)) != ::NO_ERROR) { |
| return ::SYSTEM_ERROR; |
| } |
| |
| for (uint32_t i = 0; i < aliases.size(); i++) { |
| String8 name8(aliases[i]); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, targetUid)); |
| mKeyStore->del(filename.string(), ::TYPE_ANY, get_user_id(targetUid)); |
| } |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::addRngEntropy(const uint8_t* data, size_t dataLength) { |
| const auto* device = mKeyStore->getDevice(); |
| const auto* fallback = mKeyStore->getFallbackDevice(); |
| int32_t devResult = KM_ERROR_UNIMPLEMENTED; |
| int32_t fallbackResult = KM_ERROR_UNIMPLEMENTED; |
| if (device->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_1_0 && |
| device->add_rng_entropy != NULL) { |
| devResult = device->add_rng_entropy(device, data, dataLength); |
| } |
| if (fallback->add_rng_entropy) { |
| fallbackResult = fallback->add_rng_entropy(fallback, data, dataLength); |
| } |
| if (devResult) { |
| return devResult; |
| } |
| if (fallbackResult) { |
| return fallbackResult; |
| } |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::generateKey(const String16& name, const KeymasterArguments& params, |
| const uint8_t* entropy, size_t entropyLength, int uid, |
| int flags, KeyCharacteristics* outCharacteristics) { |
| uid = getEffectiveUid(uid); |
| int rc = checkBinderPermissionAndKeystoreState(P_INSERT, uid, flags & KEYSTORE_FLAG_ENCRYPTED); |
| if (rc != ::NO_ERROR) { |
| return rc; |
| } |
| |
| rc = KM_ERROR_UNIMPLEMENTED; |
| bool isFallback = false; |
| keymaster_key_blob_t blob; |
| keymaster_key_characteristics_t out = {{nullptr, 0}, {nullptr, 0}}; |
| |
| const auto* device = mKeyStore->getDevice(); |
| const auto* fallback = mKeyStore->getFallbackDevice(); |
| std::vector<keymaster_key_param_t> opParams(params.params); |
| const keymaster_key_param_set_t inParams = {opParams.data(), opParams.size()}; |
| if (device == NULL) { |
| return ::SYSTEM_ERROR; |
| } |
| // TODO: Seed from Linux RNG before this. |
| if (device->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_1_0 && |
| device->generate_key != NULL) { |
| if (!entropy) { |
| rc = KM_ERROR_OK; |
| } else if (device->add_rng_entropy) { |
| rc = device->add_rng_entropy(device, entropy, entropyLength); |
| } else { |
| rc = KM_ERROR_UNIMPLEMENTED; |
| } |
| if (rc == KM_ERROR_OK) { |
| rc = |
| device->generate_key(device, &inParams, &blob, outCharacteristics ? &out : nullptr); |
| } |
| } |
| // If the HW device didn't support generate_key or generate_key failed |
| // fall back to the software implementation. |
| if (rc && fallback->generate_key != NULL) { |
| ALOGW("Primary keymaster device failed to generate key, falling back to SW."); |
| isFallback = true; |
| if (!entropy) { |
| rc = KM_ERROR_OK; |
| } else if (fallback->add_rng_entropy) { |
| rc = fallback->add_rng_entropy(fallback, entropy, entropyLength); |
| } else { |
| rc = KM_ERROR_UNIMPLEMENTED; |
| } |
| if (rc == KM_ERROR_OK) { |
| rc = fallback->generate_key(fallback, &inParams, &blob, |
| outCharacteristics ? &out : nullptr); |
| } |
| } |
| |
| if (outCharacteristics) { |
| outCharacteristics->characteristics = out; |
| } |
| |
| if (rc) { |
| return rc; |
| } |
| |
| String8 name8(name); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, uid)); |
| |
| Blob keyBlob(blob.key_material, blob.key_material_size, NULL, 0, ::TYPE_KEYMASTER_10); |
| keyBlob.setFallback(isFallback); |
| keyBlob.setEncrypted(flags & KEYSTORE_FLAG_ENCRYPTED); |
| |
| free(const_cast<uint8_t*>(blob.key_material)); |
| |
| return mKeyStore->put(filename.string(), &keyBlob, get_user_id(uid)); |
| } |
| |
| int32_t KeyStoreService::getKeyCharacteristics(const String16& name, |
| const keymaster_blob_t* clientId, |
| const keymaster_blob_t* appData, int32_t uid, |
| KeyCharacteristics* outCharacteristics) { |
| if (!outCharacteristics) { |
| return KM_ERROR_UNEXPECTED_NULL_POINTER; |
| } |
| |
| uid_t targetUid = getEffectiveUid(uid); |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| if (!is_granted_to(callingUid, targetUid)) { |
| ALOGW("uid %d not permitted to act for uid %d in getKeyCharacteristics", callingUid, |
| targetUid); |
| return ::PERMISSION_DENIED; |
| } |
| |
| Blob keyBlob; |
| String8 name8(name); |
| int rc; |
| |
| ResponseCode responseCode = |
| mKeyStore->getKeyForName(&keyBlob, name8, targetUid, TYPE_KEYMASTER_10); |
| if (responseCode != ::NO_ERROR) { |
| return responseCode; |
| } |
| keymaster_key_blob_t key = {keyBlob.getValue(), static_cast<size_t>(keyBlob.getLength())}; |
| auto* dev = mKeyStore->getDeviceForBlob(keyBlob); |
| keymaster_key_characteristics_t out = {}; |
| if (!dev->get_key_characteristics) { |
| ALOGE("device does not implement get_key_characteristics"); |
| return KM_ERROR_UNIMPLEMENTED; |
| } |
| rc = dev->get_key_characteristics(dev, &key, clientId, appData, &out); |
| if (rc == KM_ERROR_KEY_REQUIRES_UPGRADE) { |
| AuthorizationSet upgradeParams; |
| if (clientId && clientId->data && clientId->data_length) { |
| upgradeParams.push_back(TAG_APPLICATION_ID, *clientId); |
| } |
| if (appData && appData->data && appData->data_length) { |
| upgradeParams.push_back(TAG_APPLICATION_DATA, *appData); |
| } |
| rc = upgradeKeyBlob(name, targetUid, upgradeParams, &keyBlob); |
| if (rc != ::NO_ERROR) { |
| return rc; |
| } |
| key = {keyBlob.getValue(), static_cast<size_t>(keyBlob.getLength())}; |
| rc = dev->get_key_characteristics(dev, &key, clientId, appData, &out); |
| } |
| if (rc != KM_ERROR_OK) { |
| return rc; |
| } |
| |
| outCharacteristics->characteristics = out; |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::importKey(const String16& name, const KeymasterArguments& params, |
| keymaster_key_format_t format, const uint8_t* keyData, |
| size_t keyLength, int uid, int flags, |
| KeyCharacteristics* outCharacteristics) { |
| uid = getEffectiveUid(uid); |
| int rc = checkBinderPermissionAndKeystoreState(P_INSERT, uid, flags & KEYSTORE_FLAG_ENCRYPTED); |
| if (rc != ::NO_ERROR) { |
| return rc; |
| } |
| |
| rc = KM_ERROR_UNIMPLEMENTED; |
| bool isFallback = false; |
| keymaster_key_blob_t blob; |
| keymaster_key_characteristics_t out = {{nullptr, 0}, {nullptr, 0}}; |
| |
| const auto* device = mKeyStore->getDevice(); |
| const auto* fallback = mKeyStore->getFallbackDevice(); |
| std::vector<keymaster_key_param_t> opParams(params.params); |
| const keymaster_key_param_set_t inParams = {opParams.data(), opParams.size()}; |
| const keymaster_blob_t input = {keyData, keyLength}; |
| if (device == NULL) { |
| return ::SYSTEM_ERROR; |
| } |
| if (device->common.module->module_api_version >= KEYMASTER_MODULE_API_VERSION_1_0 && |
| device->import_key != NULL) { |
| rc = device->import_key(device, &inParams, format, &input, &blob, |
| outCharacteristics ? &out : nullptr); |
| } |
| if (rc && fallback->import_key != NULL) { |
| ALOGW("Primary keymaster device failed to import key, falling back to SW."); |
| isFallback = true; |
| rc = fallback->import_key(fallback, &inParams, format, &input, &blob, |
| outCharacteristics ? &out : nullptr); |
| } |
| if (outCharacteristics) { |
| outCharacteristics->characteristics = out; |
| } |
| |
| if (rc) { |
| return rc; |
| } |
| |
| String8 name8(name); |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, uid)); |
| |
| Blob keyBlob(blob.key_material, blob.key_material_size, NULL, 0, ::TYPE_KEYMASTER_10); |
| keyBlob.setFallback(isFallback); |
| keyBlob.setEncrypted(flags & KEYSTORE_FLAG_ENCRYPTED); |
| |
| free(const_cast<uint8_t*>(blob.key_material)); |
| |
| return mKeyStore->put(filename.string(), &keyBlob, get_user_id(uid)); |
| } |
| |
| void KeyStoreService::exportKey(const String16& name, keymaster_key_format_t format, |
| const keymaster_blob_t* clientId, const keymaster_blob_t* appData, |
| int32_t uid, ExportResult* result) { |
| |
| uid_t targetUid = getEffectiveUid(uid); |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| if (!is_granted_to(callingUid, targetUid)) { |
| ALOGW("uid %d not permitted to act for uid %d in exportKey", callingUid, targetUid); |
| result->resultCode = ::PERMISSION_DENIED; |
| return; |
| } |
| |
| Blob keyBlob; |
| String8 name8(name); |
| int rc; |
| |
| ResponseCode responseCode = |
| mKeyStore->getKeyForName(&keyBlob, name8, targetUid, TYPE_KEYMASTER_10); |
| if (responseCode != ::NO_ERROR) { |
| result->resultCode = responseCode; |
| return; |
| } |
| keymaster_key_blob_t key; |
| key.key_material_size = keyBlob.getLength(); |
| key.key_material = keyBlob.getValue(); |
| auto* dev = mKeyStore->getDeviceForBlob(keyBlob); |
| if (!dev->export_key) { |
| result->resultCode = KM_ERROR_UNIMPLEMENTED; |
| return; |
| } |
| keymaster_blob_t output = {NULL, 0}; |
| rc = dev->export_key(dev, format, &key, clientId, appData, &output); |
| result->exportData.reset(const_cast<uint8_t*>(output.data)); |
| result->dataLength = output.data_length; |
| result->resultCode = rc ? rc : ::NO_ERROR; |
| } |
| |
| void KeyStoreService::begin(const sp<IBinder>& appToken, const String16& name, |
| keymaster_purpose_t purpose, bool pruneable, |
| const KeymasterArguments& params, const uint8_t* entropy, |
| size_t entropyLength, int32_t uid, OperationResult* result) { |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| uid_t targetUid = getEffectiveUid(uid); |
| if (!is_granted_to(callingUid, targetUid)) { |
| ALOGW("uid %d not permitted to act for uid %d in begin", callingUid, targetUid); |
| result->resultCode = ::PERMISSION_DENIED; |
| return; |
| } |
| if (!pruneable && get_app_id(callingUid) != AID_SYSTEM) { |
| ALOGE("Non-system uid %d trying to start non-pruneable operation", callingUid); |
| result->resultCode = ::PERMISSION_DENIED; |
| return; |
| } |
| if (!checkAllowedOperationParams(params.params)) { |
| result->resultCode = KM_ERROR_INVALID_ARGUMENT; |
| return; |
| } |
| Blob keyBlob; |
| String8 name8(name); |
| ResponseCode responseCode = |
| mKeyStore->getKeyForName(&keyBlob, name8, targetUid, TYPE_KEYMASTER_10); |
| if (responseCode != ::NO_ERROR) { |
| result->resultCode = responseCode; |
| return; |
| } |
| keymaster_key_blob_t key; |
| key.key_material_size = keyBlob.getLength(); |
| key.key_material = keyBlob.getValue(); |
| keymaster_operation_handle_t handle; |
| auto* dev = mKeyStore->getDeviceForBlob(keyBlob); |
| keymaster_error_t err = KM_ERROR_UNIMPLEMENTED; |
| std::vector<keymaster_key_param_t> opParams(params.params); |
| Unique_keymaster_key_characteristics characteristics; |
| characteristics.reset(new keymaster_key_characteristics_t); |
| err = getOperationCharacteristics(key, dev, opParams, characteristics.get()); |
| if (err == KM_ERROR_KEY_REQUIRES_UPGRADE) { |
| int32_t rc = upgradeKeyBlob(name, targetUid, |
| AuthorizationSet(opParams.data(), opParams.size()), &keyBlob); |
| if (rc != ::NO_ERROR) { |
| result->resultCode = rc; |
| return; |
| } |
| key = {keyBlob.getValue(), static_cast<size_t>(keyBlob.getLength())}; |
| err = getOperationCharacteristics(key, dev, opParams, characteristics.get()); |
| } |
| if (err) { |
| result->resultCode = err; |
| return; |
| } |
| const hw_auth_token_t* authToken = NULL; |
| int32_t authResult = getAuthToken(characteristics.get(), 0, purpose, &authToken, |
| /*failOnTokenMissing*/ false); |
| // If per-operation auth is needed we need to begin the operation and |
| // the client will need to authorize that operation before calling |
| // update. Any other auth issues stop here. |
| if (authResult != ::NO_ERROR && authResult != ::OP_AUTH_NEEDED) { |
| result->resultCode = authResult; |
| return; |
| } |
| addAuthToParams(&opParams, authToken); |
| // Add entropy to the device first. |
| if (entropy) { |
| if (dev->add_rng_entropy) { |
| err = dev->add_rng_entropy(dev, entropy, entropyLength); |
| } else { |
| err = KM_ERROR_UNIMPLEMENTED; |
| } |
| if (err) { |
| result->resultCode = err; |
| return; |
| } |
| } |
| keymaster_key_param_set_t inParams = {opParams.data(), opParams.size()}; |
| |
| // Create a keyid for this key. |
| keymaster::km_id_t keyid; |
| if (!enforcement_policy.CreateKeyId(key, &keyid)) { |
| ALOGE("Failed to create a key ID for authorization checking."); |
| result->resultCode = KM_ERROR_UNKNOWN_ERROR; |
| return; |
| } |
| |
| // Check that all key authorization policy requirements are met. |
| keymaster::AuthorizationSet key_auths(characteristics->hw_enforced); |
| key_auths.push_back(characteristics->sw_enforced); |
| keymaster::AuthorizationSet operation_params(inParams); |
| err = enforcement_policy.AuthorizeOperation(purpose, keyid, key_auths, operation_params, |
| 0 /* op_handle */, true /* is_begin_operation */); |
| if (err) { |
| result->resultCode = err; |
| return; |
| } |
| |
| keymaster_key_param_set_t outParams = {NULL, 0}; |
| |
| // If there are more than MAX_OPERATIONS, abort the oldest operation that was started as |
| // pruneable. |
| while (mOperationMap.getOperationCount() >= MAX_OPERATIONS) { |
| ALOGD("Reached or exceeded concurrent operations limit"); |
| if (!pruneOperation()) { |
| break; |
| } |
| } |
| |
| err = dev->begin(dev, purpose, &key, &inParams, &outParams, &handle); |
| if (err != KM_ERROR_OK) { |
| ALOGE("Got error %d from begin()", err); |
| } |
| |
| // If there are too many operations abort the oldest operation that was |
| // started as pruneable and try again. |
| while (err == KM_ERROR_TOO_MANY_OPERATIONS && mOperationMap.hasPruneableOperation()) { |
| ALOGE("Ran out of operation handles"); |
| if (!pruneOperation()) { |
| break; |
| } |
| err = dev->begin(dev, purpose, &key, &inParams, &outParams, &handle); |
| } |
| if (err) { |
| result->resultCode = err; |
| return; |
| } |
| |
| sp<IBinder> operationToken = mOperationMap.addOperation(handle, keyid, purpose, dev, appToken, |
| characteristics.release(), pruneable); |
| if (authToken) { |
| mOperationMap.setOperationAuthToken(operationToken, authToken); |
| } |
| // Return the authentication lookup result. If this is a per operation |
| // auth'd key then the resultCode will be ::OP_AUTH_NEEDED and the |
| // application should get an auth token using the handle before the |
| // first call to update, which will fail if keystore hasn't received the |
| // auth token. |
| result->resultCode = authResult; |
| result->token = operationToken; |
| result->handle = handle; |
| if (outParams.params) { |
| result->outParams.params.assign(outParams.params, outParams.params + outParams.length); |
| free(outParams.params); |
| } |
| } |
| |
| void KeyStoreService::update(const sp<IBinder>& token, const KeymasterArguments& params, |
| const uint8_t* data, size_t dataLength, OperationResult* result) { |
| if (!checkAllowedOperationParams(params.params)) { |
| result->resultCode = KM_ERROR_INVALID_ARGUMENT; |
| return; |
| } |
| const keymaster2_device_t* dev; |
| keymaster_operation_handle_t handle; |
| keymaster_purpose_t purpose; |
| keymaster::km_id_t keyid; |
| const keymaster_key_characteristics_t* characteristics; |
| if (!mOperationMap.getOperation(token, &handle, &keyid, &purpose, &dev, &characteristics)) { |
| result->resultCode = KM_ERROR_INVALID_OPERATION_HANDLE; |
| return; |
| } |
| std::vector<keymaster_key_param_t> opParams(params.params); |
| int32_t authResult = addOperationAuthTokenIfNeeded(token, &opParams); |
| if (authResult != ::NO_ERROR) { |
| result->resultCode = authResult; |
| return; |
| } |
| keymaster_key_param_set_t inParams = {opParams.data(), opParams.size()}; |
| keymaster_blob_t input = {data, dataLength}; |
| size_t consumed = 0; |
| keymaster_blob_t output = {NULL, 0}; |
| keymaster_key_param_set_t outParams = {NULL, 0}; |
| |
| // Check that all key authorization policy requirements are met. |
| keymaster::AuthorizationSet key_auths(characteristics->hw_enforced); |
| key_auths.push_back(characteristics->sw_enforced); |
| keymaster::AuthorizationSet operation_params(inParams); |
| result->resultCode = enforcement_policy.AuthorizeOperation( |
| purpose, keyid, key_auths, operation_params, handle, false /* is_begin_operation */); |
| if (result->resultCode) { |
| return; |
| } |
| |
| keymaster_error_t err = |
| dev->update(dev, handle, &inParams, &input, &consumed, &outParams, &output); |
| result->data.reset(const_cast<uint8_t*>(output.data)); |
| result->dataLength = output.data_length; |
| result->inputConsumed = consumed; |
| result->resultCode = err ? (int32_t)err : ::NO_ERROR; |
| if (outParams.params) { |
| result->outParams.params.assign(outParams.params, outParams.params + outParams.length); |
| free(outParams.params); |
| } |
| } |
| |
| void KeyStoreService::finish(const sp<IBinder>& token, const KeymasterArguments& params, |
| const uint8_t* signature, size_t signatureLength, |
| const uint8_t* entropy, size_t entropyLength, |
| OperationResult* result) { |
| if (!checkAllowedOperationParams(params.params)) { |
| result->resultCode = KM_ERROR_INVALID_ARGUMENT; |
| return; |
| } |
| const keymaster2_device_t* dev; |
| keymaster_operation_handle_t handle; |
| keymaster_purpose_t purpose; |
| keymaster::km_id_t keyid; |
| const keymaster_key_characteristics_t* characteristics; |
| if (!mOperationMap.getOperation(token, &handle, &keyid, &purpose, &dev, &characteristics)) { |
| result->resultCode = KM_ERROR_INVALID_OPERATION_HANDLE; |
| return; |
| } |
| std::vector<keymaster_key_param_t> opParams(params.params); |
| int32_t authResult = addOperationAuthTokenIfNeeded(token, &opParams); |
| if (authResult != ::NO_ERROR) { |
| result->resultCode = authResult; |
| return; |
| } |
| keymaster_error_t err; |
| if (entropy) { |
| if (dev->add_rng_entropy) { |
| err = dev->add_rng_entropy(dev, entropy, entropyLength); |
| } else { |
| err = KM_ERROR_UNIMPLEMENTED; |
| } |
| if (err) { |
| result->resultCode = err; |
| return; |
| } |
| } |
| |
| keymaster_key_param_set_t inParams = {opParams.data(), opParams.size()}; |
| keymaster_blob_t input = {nullptr, 0}; |
| keymaster_blob_t sig = {signature, signatureLength}; |
| keymaster_blob_t output = {nullptr, 0}; |
| keymaster_key_param_set_t outParams = {nullptr, 0}; |
| |
| // Check that all key authorization policy requirements are met. |
| keymaster::AuthorizationSet key_auths(characteristics->hw_enforced); |
| key_auths.push_back(characteristics->sw_enforced); |
| keymaster::AuthorizationSet operation_params(inParams); |
| err = enforcement_policy.AuthorizeOperation(purpose, keyid, key_auths, operation_params, handle, |
| false /* is_begin_operation */); |
| if (err) { |
| result->resultCode = err; |
| return; |
| } |
| |
| err = |
| dev->finish(dev, handle, &inParams, &input /* TODO(swillden): wire up input to finish() */, |
| &sig, &outParams, &output); |
| // Remove the operation regardless of the result |
| mOperationMap.removeOperation(token); |
| mAuthTokenTable.MarkCompleted(handle); |
| |
| result->data.reset(const_cast<uint8_t*>(output.data)); |
| result->dataLength = output.data_length; |
| result->resultCode = err ? (int32_t)err : ::NO_ERROR; |
| if (outParams.params) { |
| result->outParams.params.assign(outParams.params, outParams.params + outParams.length); |
| free(outParams.params); |
| } |
| } |
| |
| int32_t KeyStoreService::abort(const sp<IBinder>& token) { |
| const keymaster2_device_t* dev; |
| keymaster_operation_handle_t handle; |
| keymaster_purpose_t purpose; |
| keymaster::km_id_t keyid; |
| if (!mOperationMap.getOperation(token, &handle, &keyid, &purpose, &dev, NULL)) { |
| return KM_ERROR_INVALID_OPERATION_HANDLE; |
| } |
| mOperationMap.removeOperation(token); |
| int32_t rc; |
| if (!dev->abort) { |
| rc = KM_ERROR_UNIMPLEMENTED; |
| } else { |
| rc = dev->abort(dev, handle); |
| } |
| mAuthTokenTable.MarkCompleted(handle); |
| if (rc) { |
| return rc; |
| } |
| return ::NO_ERROR; |
| } |
| |
| bool KeyStoreService::isOperationAuthorized(const sp<IBinder>& token) { |
| const keymaster2_device_t* dev; |
| keymaster_operation_handle_t handle; |
| const keymaster_key_characteristics_t* characteristics; |
| keymaster_purpose_t purpose; |
| keymaster::km_id_t keyid; |
| if (!mOperationMap.getOperation(token, &handle, &keyid, &purpose, &dev, &characteristics)) { |
| return false; |
| } |
| const hw_auth_token_t* authToken = NULL; |
| mOperationMap.getOperationAuthToken(token, &authToken); |
| std::vector<keymaster_key_param_t> ignored; |
| int32_t authResult = addOperationAuthTokenIfNeeded(token, &ignored); |
| return authResult == ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::addAuthToken(const uint8_t* token, size_t length) { |
| if (!checkBinderPermission(P_ADD_AUTH)) { |
| ALOGW("addAuthToken: permission denied for %d", IPCThreadState::self()->getCallingUid()); |
| return ::PERMISSION_DENIED; |
| } |
| if (length != sizeof(hw_auth_token_t)) { |
| return KM_ERROR_INVALID_ARGUMENT; |
| } |
| hw_auth_token_t* authToken = new hw_auth_token_t; |
| memcpy(reinterpret_cast<void*>(authToken), token, sizeof(hw_auth_token_t)); |
| // The table takes ownership of authToken. |
| mAuthTokenTable.AddAuthenticationToken(authToken); |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::attestKey(const String16& name, const KeymasterArguments& params, |
| KeymasterCertificateChain* outChain) { |
| if (!outChain) |
| return KM_ERROR_OUTPUT_PARAMETER_NULL; |
| |
| if (!checkAllowedOperationParams(params.params)) { |
| return KM_ERROR_INVALID_ARGUMENT; |
| } |
| |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| |
| Blob keyBlob; |
| String8 name8(name); |
| ResponseCode responseCode = |
| mKeyStore->getKeyForName(&keyBlob, name8, callingUid, TYPE_KEYMASTER_10); |
| if (responseCode != ::NO_ERROR) { |
| return responseCode; |
| } |
| |
| keymaster_key_blob_t key = {keyBlob.getValue(), |
| static_cast<size_t>(std::max(0, keyBlob.getLength()))}; |
| auto* dev = mKeyStore->getDeviceForBlob(keyBlob); |
| if (!dev->attest_key) |
| return KM_ERROR_UNIMPLEMENTED; |
| |
| const keymaster_key_param_set_t in_params = { |
| const_cast<keymaster_key_param_t*>(params.params.data()), params.params.size()}; |
| outChain->chain = {nullptr, 0}; |
| int32_t rc = dev->attest_key(dev, &key, &in_params, &outChain->chain); |
| if (rc) |
| return rc; |
| return ::NO_ERROR; |
| } |
| |
| /** |
| * Prune the oldest pruneable operation. |
| */ |
| bool KeyStoreService::pruneOperation() { |
| sp<IBinder> oldest = mOperationMap.getOldestPruneableOperation(); |
| ALOGD("Trying to prune operation %p", oldest.get()); |
| size_t op_count_before_abort = mOperationMap.getOperationCount(); |
| // We mostly ignore errors from abort() because all we care about is whether at least |
| // one operation has been removed. |
| int abort_error = abort(oldest); |
| if (mOperationMap.getOperationCount() >= op_count_before_abort) { |
| ALOGE("Failed to abort pruneable operation %p, error: %d", oldest.get(), abort_error); |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Get the effective target uid for a binder operation that takes an |
| * optional uid as the target. |
| */ |
| uid_t KeyStoreService::getEffectiveUid(int32_t targetUid) { |
| if (targetUid == UID_SELF) { |
| return IPCThreadState::self()->getCallingUid(); |
| } |
| return static_cast<uid_t>(targetUid); |
| } |
| |
| /** |
| * Check if the caller of the current binder method has the required |
| * permission and if acting on other uids the grants to do so. |
| */ |
| bool KeyStoreService::checkBinderPermission(perm_t permission, int32_t targetUid) { |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| pid_t spid = IPCThreadState::self()->getCallingPid(); |
| if (!has_permission(callingUid, permission, spid)) { |
| ALOGW("permission %s denied for %d", get_perm_label(permission), callingUid); |
| return false; |
| } |
| if (!is_granted_to(callingUid, getEffectiveUid(targetUid))) { |
| ALOGW("uid %d not granted to act for %d", callingUid, targetUid); |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Check if the caller of the current binder method has the required |
| * permission and the target uid is the caller or the caller is system. |
| */ |
| bool KeyStoreService::checkBinderPermissionSelfOrSystem(perm_t permission, int32_t targetUid) { |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| pid_t spid = IPCThreadState::self()->getCallingPid(); |
| if (!has_permission(callingUid, permission, spid)) { |
| ALOGW("permission %s denied for %d", get_perm_label(permission), callingUid); |
| return false; |
| } |
| return getEffectiveUid(targetUid) == callingUid || callingUid == AID_SYSTEM; |
| } |
| |
| /** |
| * Check if the caller of the current binder method has the required |
| * permission or the target of the operation is the caller's uid. This is |
| * for operation where the permission is only for cross-uid activity and all |
| * uids are allowed to act on their own (ie: clearing all entries for a |
| * given uid). |
| */ |
| bool KeyStoreService::checkBinderPermissionOrSelfTarget(perm_t permission, int32_t targetUid) { |
| uid_t callingUid = IPCThreadState::self()->getCallingUid(); |
| if (getEffectiveUid(targetUid) == callingUid) { |
| return true; |
| } else { |
| return checkBinderPermission(permission, targetUid); |
| } |
| } |
| |
| /** |
| * Helper method to check that the caller has the required permission as |
| * well as the keystore is in the unlocked state if checkUnlocked is true. |
| * |
| * Returns NO_ERROR on success, PERMISSION_DENIED on a permission error and |
| * otherwise the state of keystore when not unlocked and checkUnlocked is |
| * true. |
| */ |
| int32_t KeyStoreService::checkBinderPermissionAndKeystoreState(perm_t permission, int32_t targetUid, |
| bool checkUnlocked) { |
| if (!checkBinderPermission(permission, targetUid)) { |
| return ::PERMISSION_DENIED; |
| } |
| State state = mKeyStore->getState(get_user_id(getEffectiveUid(targetUid))); |
| if (checkUnlocked && !isKeystoreUnlocked(state)) { |
| return state; |
| } |
| |
| return ::NO_ERROR; |
| } |
| |
| bool KeyStoreService::isKeystoreUnlocked(State state) { |
| switch (state) { |
| case ::STATE_NO_ERROR: |
| return true; |
| case ::STATE_UNINITIALIZED: |
| case ::STATE_LOCKED: |
| return false; |
| } |
| return false; |
| } |
| |
| bool KeyStoreService::isKeyTypeSupported(const keymaster2_device_t* device, |
| keymaster_keypair_t keyType) { |
| const int32_t device_api = device->common.module->module_api_version; |
| if (device_api == KEYMASTER_MODULE_API_VERSION_0_2) { |
| switch (keyType) { |
| case TYPE_RSA: |
| case TYPE_DSA: |
| case TYPE_EC: |
| return true; |
| default: |
| return false; |
| } |
| } else if (device_api >= KEYMASTER_MODULE_API_VERSION_0_3) { |
| switch (keyType) { |
| case TYPE_RSA: |
| return true; |
| case TYPE_DSA: |
| return device->flags & KEYMASTER_SUPPORTS_DSA; |
| case TYPE_EC: |
| return device->flags & KEYMASTER_SUPPORTS_EC; |
| default: |
| return false; |
| } |
| } else { |
| return keyType == TYPE_RSA; |
| } |
| } |
| |
| /** |
| * Check that all keymaster_key_param_t's provided by the application are |
| * allowed. Any parameter that keystore adds itself should be disallowed here. |
| */ |
| bool KeyStoreService::checkAllowedOperationParams( |
| const std::vector<keymaster_key_param_t>& params) { |
| for (auto param : params) { |
| switch (param.tag) { |
| case KM_TAG_AUTH_TOKEN: |
| return false; |
| default: |
| break; |
| } |
| } |
| return true; |
| } |
| |
| keymaster_error_t KeyStoreService::getOperationCharacteristics( |
| const keymaster_key_blob_t& key, const keymaster2_device_t* dev, |
| const std::vector<keymaster_key_param_t>& params, keymaster_key_characteristics_t* out) { |
| UniquePtr<keymaster_blob_t> appId; |
| UniquePtr<keymaster_blob_t> appData; |
| for (auto param : params) { |
| if (param.tag == KM_TAG_APPLICATION_ID) { |
| appId.reset(new keymaster_blob_t); |
| appId->data = param.blob.data; |
| appId->data_length = param.blob.data_length; |
| } else if (param.tag == KM_TAG_APPLICATION_DATA) { |
| appData.reset(new keymaster_blob_t); |
| appData->data = param.blob.data; |
| appData->data_length = param.blob.data_length; |
| } |
| } |
| keymaster_key_characteristics_t result = {{nullptr, 0}, {nullptr, 0}}; |
| if (!dev->get_key_characteristics) { |
| return KM_ERROR_UNIMPLEMENTED; |
| } |
| keymaster_error_t error = |
| dev->get_key_characteristics(dev, &key, appId.get(), appData.get(), &result); |
| if (error == KM_ERROR_OK) { |
| *out = result; |
| } |
| return error; |
| } |
| |
| /** |
| * Get the auth token for this operation from the auth token table. |
| * |
| * Returns ::NO_ERROR if the auth token was set or none was required. |
| * ::OP_AUTH_NEEDED if it is a per op authorization, no |
| * authorization token exists for that operation and |
| * failOnTokenMissing is false. |
| * KM_ERROR_KEY_USER_NOT_AUTHENTICATED if there is no valid auth |
| * token for the operation |
| */ |
| int32_t KeyStoreService::getAuthToken(const keymaster_key_characteristics_t* characteristics, |
| keymaster_operation_handle_t handle, |
| keymaster_purpose_t purpose, |
| const hw_auth_token_t** authToken, bool failOnTokenMissing) { |
| |
| std::vector<keymaster_key_param_t> allCharacteristics; |
| for (size_t i = 0; i < characteristics->sw_enforced.length; i++) { |
| allCharacteristics.push_back(characteristics->sw_enforced.params[i]); |
| } |
| for (size_t i = 0; i < characteristics->hw_enforced.length; i++) { |
| allCharacteristics.push_back(characteristics->hw_enforced.params[i]); |
| } |
| keymaster::AuthTokenTable::Error err = mAuthTokenTable.FindAuthorization( |
| allCharacteristics.data(), allCharacteristics.size(), purpose, handle, authToken); |
| switch (err) { |
| case keymaster::AuthTokenTable::OK: |
| case keymaster::AuthTokenTable::AUTH_NOT_REQUIRED: |
| return ::NO_ERROR; |
| case keymaster::AuthTokenTable::AUTH_TOKEN_NOT_FOUND: |
| case keymaster::AuthTokenTable::AUTH_TOKEN_EXPIRED: |
| case keymaster::AuthTokenTable::AUTH_TOKEN_WRONG_SID: |
| return KM_ERROR_KEY_USER_NOT_AUTHENTICATED; |
| case keymaster::AuthTokenTable::OP_HANDLE_REQUIRED: |
| return failOnTokenMissing ? (int32_t)KM_ERROR_KEY_USER_NOT_AUTHENTICATED |
| : (int32_t)::OP_AUTH_NEEDED; |
| default: |
| ALOGE("Unexpected FindAuthorization return value %d", err); |
| return KM_ERROR_INVALID_ARGUMENT; |
| } |
| } |
| |
| inline void KeyStoreService::addAuthToParams(std::vector<keymaster_key_param_t>* params, |
| const hw_auth_token_t* token) { |
| if (token) { |
| params->push_back(keymaster_param_blob( |
| KM_TAG_AUTH_TOKEN, reinterpret_cast<const uint8_t*>(token), sizeof(hw_auth_token_t))); |
| } |
| } |
| |
| /** |
| * Add the auth token for the operation to the param list if the operation |
| * requires authorization. Uses the cached result in the OperationMap if available |
| * otherwise gets the token from the AuthTokenTable and caches the result. |
| * |
| * Returns ::NO_ERROR if the auth token was added or not needed. |
| * KM_ERROR_KEY_USER_NOT_AUTHENTICATED if the operation is not |
| * authenticated. |
| * KM_ERROR_INVALID_OPERATION_HANDLE if token is not a valid |
| * operation token. |
| */ |
| int32_t KeyStoreService::addOperationAuthTokenIfNeeded(sp<IBinder> token, |
| std::vector<keymaster_key_param_t>* params) { |
| const hw_auth_token_t* authToken = NULL; |
| mOperationMap.getOperationAuthToken(token, &authToken); |
| if (!authToken) { |
| const keymaster2_device_t* dev; |
| keymaster_operation_handle_t handle; |
| const keymaster_key_characteristics_t* characteristics = NULL; |
| keymaster_purpose_t purpose; |
| keymaster::km_id_t keyid; |
| if (!mOperationMap.getOperation(token, &handle, &keyid, &purpose, &dev, &characteristics)) { |
| return KM_ERROR_INVALID_OPERATION_HANDLE; |
| } |
| int32_t result = getAuthToken(characteristics, handle, purpose, &authToken); |
| if (result != ::NO_ERROR) { |
| return result; |
| } |
| if (authToken) { |
| mOperationMap.setOperationAuthToken(token, authToken); |
| } |
| } |
| addAuthToParams(params, authToken); |
| return ::NO_ERROR; |
| } |
| |
| /** |
| * Translate a result value to a legacy return value. All keystore errors are |
| * preserved and keymaster errors become SYSTEM_ERRORs |
| */ |
| int32_t KeyStoreService::translateResultToLegacyResult(int32_t result) { |
| if (result > 0) { |
| return result; |
| } |
| return ::SYSTEM_ERROR; |
| } |
| |
| keymaster_key_param_t* |
| KeyStoreService::getKeyAlgorithm(keymaster_key_characteristics_t* characteristics) { |
| for (size_t i = 0; i < characteristics->hw_enforced.length; i++) { |
| if (characteristics->hw_enforced.params[i].tag == KM_TAG_ALGORITHM) { |
| return &characteristics->hw_enforced.params[i]; |
| } |
| } |
| for (size_t i = 0; i < characteristics->sw_enforced.length; i++) { |
| if (characteristics->sw_enforced.params[i].tag == KM_TAG_ALGORITHM) { |
| return &characteristics->sw_enforced.params[i]; |
| } |
| } |
| return NULL; |
| } |
| |
| void KeyStoreService::addLegacyBeginParams(const String16& name, |
| std::vector<keymaster_key_param_t>& params) { |
| // All legacy keys are DIGEST_NONE/PAD_NONE. |
| params.push_back(keymaster_param_enum(KM_TAG_DIGEST, KM_DIGEST_NONE)); |
| params.push_back(keymaster_param_enum(KM_TAG_PADDING, KM_PAD_NONE)); |
| |
| // Look up the algorithm of the key. |
| KeyCharacteristics characteristics; |
| int32_t rc = getKeyCharacteristics(name, NULL, NULL, UID_SELF, &characteristics); |
| if (rc != ::NO_ERROR) { |
| ALOGE("Failed to get key characteristics"); |
| return; |
| } |
| keymaster_key_param_t* algorithm = getKeyAlgorithm(&characteristics.characteristics); |
| if (!algorithm) { |
| ALOGE("getKeyCharacteristics did not include KM_TAG_ALGORITHM"); |
| return; |
| } |
| params.push_back(*algorithm); |
| } |
| |
| int32_t KeyStoreService::doLegacySignVerify(const String16& name, const uint8_t* data, |
| size_t length, uint8_t** out, size_t* outLength, |
| const uint8_t* signature, size_t signatureLength, |
| keymaster_purpose_t purpose) { |
| |
| std::basic_stringstream<uint8_t> outBuffer; |
| OperationResult result; |
| KeymasterArguments inArgs; |
| addLegacyBeginParams(name, inArgs.params); |
| sp<IBinder> appToken(new BBinder); |
| sp<IBinder> token; |
| |
| begin(appToken, name, purpose, true, inArgs, NULL, 0, UID_SELF, &result); |
| if (result.resultCode != ResponseCode::NO_ERROR) { |
| if (result.resultCode == ::KEY_NOT_FOUND) { |
| ALOGW("Key not found"); |
| } else { |
| ALOGW("Error in begin: %d", result.resultCode); |
| } |
| return translateResultToLegacyResult(result.resultCode); |
| } |
| inArgs.params.clear(); |
| token = result.token; |
| size_t consumed = 0; |
| size_t lastConsumed = 0; |
| do { |
| update(token, inArgs, data + consumed, length - consumed, &result); |
| if (result.resultCode != ResponseCode::NO_ERROR) { |
| ALOGW("Error in update: %d", result.resultCode); |
| return translateResultToLegacyResult(result.resultCode); |
| } |
| if (out) { |
| outBuffer.write(result.data.get(), result.dataLength); |
| } |
| lastConsumed = result.inputConsumed; |
| consumed += lastConsumed; |
| } while (consumed < length && lastConsumed > 0); |
| |
| if (consumed != length) { |
| ALOGW("Not all data consumed. Consumed %zu of %zu", consumed, length); |
| return ::SYSTEM_ERROR; |
| } |
| |
| finish(token, inArgs, signature, signatureLength, NULL, 0, &result); |
| if (result.resultCode != ResponseCode::NO_ERROR) { |
| ALOGW("Error in finish: %d", result.resultCode); |
| return translateResultToLegacyResult(result.resultCode); |
| } |
| if (out) { |
| outBuffer.write(result.data.get(), result.dataLength); |
| } |
| |
| if (out) { |
| auto buf = outBuffer.str(); |
| *out = new uint8_t[buf.size()]; |
| memcpy(*out, buf.c_str(), buf.size()); |
| *outLength = buf.size(); |
| } |
| |
| return ::NO_ERROR; |
| } |
| |
| int32_t KeyStoreService::upgradeKeyBlob(const String16& name, uid_t uid, |
| const AuthorizationSet& params, Blob* blob) { |
| // Read the blob rather than assuming the caller provided the right name/uid/blob triplet. |
| String8 name8(name); |
| ResponseCode responseCode = mKeyStore->getKeyForName(blob, name8, uid, TYPE_KEYMASTER_10); |
| if (responseCode != ::NO_ERROR) { |
| return responseCode; |
| } |
| |
| keymaster_key_blob_t key = {blob->getValue(), static_cast<size_t>(blob->getLength())}; |
| auto* dev = mKeyStore->getDeviceForBlob(*blob); |
| keymaster_key_blob_t upgraded_key; |
| int32_t rc = dev->upgrade_key(dev, &key, ¶ms, &upgraded_key); |
| if (rc != KM_ERROR_OK) { |
| return rc; |
| } |
| UniquePtr<uint8_t, Malloc_Delete> upgraded_key_deleter( |
| const_cast<uint8_t*>(upgraded_key.key_material)); |
| |
| rc = del(name, uid); |
| if (rc != ::NO_ERROR) { |
| return rc; |
| } |
| |
| String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, uid)); |
| Blob newBlob(upgraded_key.key_material, upgraded_key.key_material_size, nullptr /* info */, |
| 0 /* infoLength */, ::TYPE_KEYMASTER_10); |
| newBlob.setFallback(blob->isFallback()); |
| newBlob.setEncrypted(blob->isEncrypted()); |
| |
| rc = mKeyStore->put(filename.string(), &newBlob, get_user_id(uid)); |
| |
| // Re-read blob for caller. We can't use newBlob because writing it modified it. |
| responseCode = mKeyStore->getKeyForName(blob, name8, uid, TYPE_KEYMASTER_10); |
| if (responseCode != ::NO_ERROR) { |
| return responseCode; |
| } |
| |
| return rc; |
| } |
| |
| } // namespace android |