| /* |
| * Copyright (C) 2015 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. |
| */ |
| #define LOG_TAG "gatekeeperd" |
| |
| #include "gatekeeperd.h" |
| |
| #include <endian.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <memory> |
| |
| #include <KeyMintUtils.h> |
| #include <android-base/logging.h> |
| #include <android-base/properties.h> |
| #include <android/binder_ibinder.h> |
| #include <android/binder_manager.h> |
| #include <binder/IPCThreadState.h> |
| #include <binder/IServiceManager.h> |
| #include <binder/PermissionCache.h> |
| #include <gatekeeper/password_handle.h> // for password_handle_t |
| #include <hardware/hw_auth_token.h> |
| #include <libgsi/libgsi.h> |
| #include <log/log.h> |
| #include <utils/String16.h> |
| |
| #include <aidl/android/hardware/security/keymint/HardwareAuthToken.h> |
| #include <aidl/android/security/authorization/IKeystoreAuthorization.h> |
| #include <hidl/HidlSupport.h> |
| |
| using android::sp; |
| using android::hardware::Return; |
| using android::hardware::gatekeeper::V1_0::GatekeeperResponse; |
| using android::hardware::gatekeeper::V1_0::GatekeeperStatusCode; |
| |
| using AidlGatekeeperEnrollResp = aidl::android::hardware::gatekeeper::GatekeeperEnrollResponse; |
| using AidlGatekeeperVerifyResp = aidl::android::hardware::gatekeeper::GatekeeperVerifyResponse; |
| |
| using GKResponseCode = ::android::service::gatekeeper::ResponseCode; |
| using ::aidl::android::hardware::security::keymint::HardwareAuthenticatorType; |
| using ::aidl::android::hardware::security::keymint::HardwareAuthToken; |
| using ::aidl::android::hardware::security::keymint::km_utils::authToken2AidlVec; |
| using ::aidl::android::security::authorization::IKeystoreAuthorization; |
| |
| namespace android { |
| |
| static const String16 KEYGUARD_PERMISSION("android.permission.ACCESS_KEYGUARD_SECURE_STORAGE"); |
| static const String16 DUMP_PERMISSION("android.permission.DUMP"); |
| constexpr const char gatekeeperServiceName[] = "android.hardware.gatekeeper.IGatekeeper/default"; |
| |
| GateKeeperProxy::GateKeeperProxy() { |
| clear_state_if_needed_done = false; |
| hw_device = IGatekeeper::getService(); |
| ::ndk::SpAIBinder ks2Binder(AServiceManager_getService(gatekeeperServiceName)); |
| aidl_hw_device = AidlIGatekeeper::fromBinder(ks2Binder); |
| is_running_gsi = android::base::GetBoolProperty(android::gsi::kGsiBootedProp, false); |
| |
| if (!aidl_hw_device && !hw_device) { |
| LOG(ERROR) << "Could not find Gatekeeper device, which makes me very sad."; |
| } |
| } |
| |
| void GateKeeperProxy::store_sid(uint32_t userId, uint64_t sid) { |
| char filename[21]; |
| snprintf(filename, sizeof(filename), "%u", userId); |
| int fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR); |
| if (fd < 0) { |
| ALOGE("could not open file: %s: %s", filename, strerror(errno)); |
| return; |
| } |
| write(fd, &sid, sizeof(sid)); |
| close(fd); |
| } |
| |
| void GateKeeperProxy::clear_state_if_needed() { |
| if (clear_state_if_needed_done) { |
| return; |
| } |
| |
| if (mark_cold_boot() && !is_running_gsi) { |
| ALOGI("cold boot: clearing state"); |
| if (aidl_hw_device) { |
| aidl_hw_device->deleteAllUsers(); |
| } else if (hw_device) { |
| hw_device->deleteAllUsers([](const GatekeeperResponse&) {}); |
| } |
| } |
| |
| clear_state_if_needed_done = true; |
| } |
| |
| bool GateKeeperProxy::mark_cold_boot() { |
| const char* filename = ".coldboot"; |
| if (access(filename, F_OK) == -1) { |
| int fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR); |
| if (fd < 0) { |
| ALOGE("could not open file: %s : %s", filename, strerror(errno)); |
| return false; |
| } |
| close(fd); |
| return true; |
| } |
| return false; |
| } |
| |
| void GateKeeperProxy::maybe_store_sid(uint32_t userId, uint64_t sid) { |
| char filename[21]; |
| snprintf(filename, sizeof(filename), "%u", userId); |
| if (access(filename, F_OK) == -1) { |
| store_sid(userId, sid); |
| } |
| } |
| |
| uint64_t GateKeeperProxy::read_sid(uint32_t userId) { |
| char filename[21]; |
| uint64_t sid; |
| snprintf(filename, sizeof(filename), "%u", userId); |
| int fd = open(filename, O_RDONLY); |
| if (fd < 0) return 0; |
| read(fd, &sid, sizeof(sid)); |
| close(fd); |
| return sid; |
| } |
| |
| void GateKeeperProxy::clear_sid(uint32_t userId) { |
| char filename[21]; |
| snprintf(filename, sizeof(filename), "%u", userId); |
| if (remove(filename) < 0 && errno != ENOENT) { |
| ALOGE("%s: could not remove file [%s], attempting 0 write", __func__, strerror(errno)); |
| store_sid(userId, 0); |
| } |
| } |
| |
| uint32_t GateKeeperProxy::adjust_userId(uint32_t userId) { |
| static constexpr uint32_t kGsiOffset = 1000000; |
| CHECK(userId < kGsiOffset); |
| CHECK((aidl_hw_device != nullptr) || (hw_device != nullptr)); |
| if (is_running_gsi) { |
| return userId + kGsiOffset; |
| } |
| return userId; |
| } |
| |
| #define GK_ERROR *gkResponse = GKResponse::error(), Status::ok() |
| |
| Status GateKeeperProxy::enroll(int32_t userId, |
| const std::optional<std::vector<uint8_t>>& currentPasswordHandle, |
| const std::optional<std::vector<uint8_t>>& currentPassword, |
| const std::vector<uint8_t>& desiredPassword, |
| GKResponse* gkResponse) { |
| IPCThreadState* ipc = IPCThreadState::self(); |
| const int calling_pid = ipc->getCallingPid(); |
| const int calling_uid = ipc->getCallingUid(); |
| if (!PermissionCache::checkPermission(KEYGUARD_PERMISSION, calling_pid, calling_uid)) { |
| return GK_ERROR; |
| } |
| |
| // Make sure to clear any state from before factory reset as soon as a credential is |
| // enrolled (which may happen during device setup). |
| clear_state_if_needed(); |
| |
| // need a desired password to enroll |
| if (desiredPassword.size() == 0) return GK_ERROR; |
| |
| if (!aidl_hw_device && !hw_device) { |
| LOG(ERROR) << "has no HAL to talk to"; |
| return GK_ERROR; |
| } |
| |
| android::hardware::hidl_vec<uint8_t> curPwdHandle; |
| android::hardware::hidl_vec<uint8_t> curPwd; |
| |
| if (currentPasswordHandle && currentPassword) { |
| if (hw_device) { |
| // Hidl Implementations expects passwordHandle to be in |
| // gatekeeper::password_handle_t format. |
| if (currentPasswordHandle->size() != sizeof(gatekeeper::password_handle_t)) { |
| LOG(INFO) << "Password handle has wrong length"; |
| return GK_ERROR; |
| } |
| } |
| curPwdHandle.setToExternal(const_cast<uint8_t*>(currentPasswordHandle->data()), |
| currentPasswordHandle->size()); |
| curPwd.setToExternal(const_cast<uint8_t*>(currentPassword->data()), |
| currentPassword->size()); |
| } |
| |
| android::hardware::hidl_vec<uint8_t> newPwd; |
| newPwd.setToExternal(const_cast<uint8_t*>(desiredPassword.data()), desiredPassword.size()); |
| |
| uint32_t hw_userId = adjust_userId(userId); |
| uint64_t secureUserId = 0; |
| if (aidl_hw_device) { |
| // AIDL gatekeeper service |
| AidlGatekeeperEnrollResp rsp; |
| auto result = aidl_hw_device->enroll(hw_userId, curPwdHandle, curPwd, newPwd, &rsp); |
| if (!result.isOk()) { |
| LOG(ERROR) << "enroll transaction failed"; |
| return GK_ERROR; |
| } |
| if (rsp.statusCode >= AidlIGatekeeper::STATUS_OK) { |
| *gkResponse = GKResponse::ok({rsp.data.begin(), rsp.data.end()}); |
| secureUserId = static_cast<uint64_t>(rsp.secureUserId); |
| } else if (rsp.statusCode == AidlIGatekeeper::ERROR_RETRY_TIMEOUT && rsp.timeoutMs > 0) { |
| *gkResponse = GKResponse::retry(rsp.timeoutMs); |
| } else { |
| *gkResponse = GKResponse::error(); |
| } |
| } else if (hw_device) { |
| // HIDL gatekeeper service |
| Return<void> hwRes = hw_device->enroll( |
| hw_userId, curPwdHandle, curPwd, newPwd, |
| [&gkResponse](const GatekeeperResponse& rsp) { |
| if (rsp.code >= GatekeeperStatusCode::STATUS_OK) { |
| *gkResponse = GKResponse::ok({rsp.data.begin(), rsp.data.end()}); |
| } else if (rsp.code == GatekeeperStatusCode::ERROR_RETRY_TIMEOUT && |
| rsp.timeout > 0) { |
| *gkResponse = GKResponse::retry(rsp.timeout); |
| } else { |
| *gkResponse = GKResponse::error(); |
| } |
| }); |
| if (!hwRes.isOk()) { |
| LOG(ERROR) << "enroll transaction failed"; |
| return GK_ERROR; |
| } |
| if (gkResponse->response_code() == GKResponseCode::OK) { |
| if (gkResponse->payload().size() != sizeof(gatekeeper::password_handle_t)) { |
| LOG(ERROR) << "HAL returned password handle of invalid length " |
| << gkResponse->payload().size(); |
| return GK_ERROR; |
| } |
| |
| const gatekeeper::password_handle_t* handle = |
| reinterpret_cast<const gatekeeper::password_handle_t*>( |
| gkResponse->payload().data()); |
| secureUserId = handle->user_id; |
| } |
| } |
| |
| if (gkResponse->response_code() == GKResponseCode::OK && !gkResponse->should_reenroll()) { |
| store_sid(userId, secureUserId); |
| |
| GKResponse verifyResponse; |
| // immediately verify this password so we don't ask the user to enter it again |
| // if they just created it. |
| auto status = verify(userId, gkResponse->payload(), desiredPassword, &verifyResponse); |
| if (!status.isOk() || verifyResponse.response_code() != GKResponseCode::OK) { |
| LOG(ERROR) << "Failed to verify password after enrolling"; |
| } |
| } |
| |
| return Status::ok(); |
| } |
| |
| Status GateKeeperProxy::verify(int32_t userId, const ::std::vector<uint8_t>& enrolledPasswordHandle, |
| const ::std::vector<uint8_t>& providedPassword, |
| GKResponse* gkResponse) { |
| return verifyChallenge(userId, 0 /* challenge */, enrolledPasswordHandle, providedPassword, |
| gkResponse); |
| } |
| |
| Status GateKeeperProxy::verifyChallenge(int32_t userId, int64_t challenge, |
| const std::vector<uint8_t>& enrolledPasswordHandle, |
| const std::vector<uint8_t>& providedPassword, |
| GKResponse* gkResponse) { |
| IPCThreadState* ipc = IPCThreadState::self(); |
| const int calling_pid = ipc->getCallingPid(); |
| const int calling_uid = ipc->getCallingUid(); |
| if (!PermissionCache::checkPermission(KEYGUARD_PERMISSION, calling_pid, calling_uid)) { |
| return GK_ERROR; |
| } |
| |
| // can't verify if we're missing either param |
| if (enrolledPasswordHandle.size() == 0 || providedPassword.size() == 0) return GK_ERROR; |
| |
| if (!aidl_hw_device && !hw_device) { |
| LOG(ERROR) << "has no HAL to talk to"; |
| return GK_ERROR; |
| } |
| |
| if (hw_device) { |
| // Hidl Implementations expects passwordHandle to be in gatekeeper::password_handle_t |
| if (enrolledPasswordHandle.size() != sizeof(gatekeeper::password_handle_t)) { |
| LOG(INFO) << "Password handle has wrong length"; |
| return GK_ERROR; |
| } |
| } |
| |
| uint32_t hw_userId = adjust_userId(userId); |
| android::hardware::hidl_vec<uint8_t> curPwdHandle; |
| curPwdHandle.setToExternal(const_cast<uint8_t*>(enrolledPasswordHandle.data()), |
| enrolledPasswordHandle.size()); |
| android::hardware::hidl_vec<uint8_t> enteredPwd; |
| enteredPwd.setToExternal(const_cast<uint8_t*>(providedPassword.data()), |
| providedPassword.size()); |
| |
| uint64_t secureUserId = 0; |
| if (aidl_hw_device) { |
| // AIDL gatekeeper service |
| AidlGatekeeperVerifyResp rsp; |
| auto result = aidl_hw_device->verify(hw_userId, challenge, curPwdHandle, enteredPwd, &rsp); |
| if (!result.isOk()) { |
| LOG(ERROR) << "verify transaction failed"; |
| return GK_ERROR; |
| } |
| if (rsp.statusCode >= AidlIGatekeeper::STATUS_OK) { |
| secureUserId = rsp.hardwareAuthToken.userId; |
| // Serialize HardwareAuthToken to a vector as hw_auth_token_t. |
| *gkResponse = GKResponse::ok( |
| authToken2AidlVec(rsp.hardwareAuthToken), |
| rsp.statusCode == AidlIGatekeeper::STATUS_REENROLL /* reenroll */); |
| } else if (rsp.statusCode == AidlIGatekeeper::ERROR_RETRY_TIMEOUT) { |
| *gkResponse = GKResponse::retry(rsp.timeoutMs); |
| } else { |
| *gkResponse = GKResponse::error(); |
| } |
| } else if (hw_device) { |
| // HIDL gatekeeper service |
| Return<void> hwRes = hw_device->verify( |
| hw_userId, challenge, curPwdHandle, enteredPwd, |
| [&gkResponse](const GatekeeperResponse& rsp) { |
| if (rsp.code >= GatekeeperStatusCode::STATUS_OK) { |
| *gkResponse = GKResponse::ok( |
| {rsp.data.begin(), rsp.data.end()}, |
| rsp.code == GatekeeperStatusCode::STATUS_REENROLL /* reenroll */); |
| } else if (rsp.code == GatekeeperStatusCode::ERROR_RETRY_TIMEOUT) { |
| *gkResponse = GKResponse::retry(rsp.timeout); |
| } else { |
| *gkResponse = GKResponse::error(); |
| } |
| }); |
| |
| if (!hwRes.isOk()) { |
| LOG(ERROR) << "verify transaction failed"; |
| return GK_ERROR; |
| } |
| const gatekeeper::password_handle_t* handle = |
| reinterpret_cast<const gatekeeper::password_handle_t*>( |
| enrolledPasswordHandle.data()); |
| secureUserId = handle->user_id; |
| } |
| |
| if (gkResponse->response_code() == GKResponseCode::OK) { |
| if (gkResponse->payload().size() != 0) { |
| // try to connect to IKeystoreAuthorization AIDL service first. |
| AIBinder* authzAIBinder = AServiceManager_getService("android.security.authorization"); |
| ::ndk::SpAIBinder authzBinder(authzAIBinder); |
| auto authzService = IKeystoreAuthorization::fromBinder(authzBinder); |
| if (authzService) { |
| if (gkResponse->payload().size() != sizeof(hw_auth_token_t)) { |
| LOG(ERROR) << "Incorrect size of AuthToken payload."; |
| return GK_ERROR; |
| } |
| |
| const hw_auth_token_t* hwAuthToken = |
| reinterpret_cast<const hw_auth_token_t*>(gkResponse->payload().data()); |
| HardwareAuthToken authToken; |
| |
| authToken.timestamp.milliSeconds = betoh64(hwAuthToken->timestamp); |
| authToken.challenge = hwAuthToken->challenge; |
| authToken.userId = hwAuthToken->user_id; |
| authToken.authenticatorId = hwAuthToken->authenticator_id; |
| authToken.authenticatorType = static_cast<HardwareAuthenticatorType>( |
| betoh32(hwAuthToken->authenticator_type)); |
| authToken.mac.assign(&hwAuthToken->hmac[0], &hwAuthToken->hmac[32]); |
| auto result = authzService->addAuthToken(authToken); |
| if (!result.isOk()) { |
| LOG(ERROR) << "Failure in sending AuthToken to AuthorizationService."; |
| return GK_ERROR; |
| } |
| } else { |
| LOG(ERROR) << "Cannot deliver auth token. Unable to communicate with " |
| "Keystore."; |
| return GK_ERROR; |
| } |
| } |
| |
| maybe_store_sid(userId, secureUserId); |
| } |
| |
| return Status::ok(); |
| } |
| |
| Status GateKeeperProxy::getSecureUserId(int32_t userId, int64_t* sid) { |
| *sid = read_sid(userId); |
| return Status::ok(); |
| } |
| |
| Status GateKeeperProxy::clearSecureUserId(int32_t userId) { |
| IPCThreadState* ipc = IPCThreadState::self(); |
| const int calling_pid = ipc->getCallingPid(); |
| const int calling_uid = ipc->getCallingUid(); |
| if (!PermissionCache::checkPermission(KEYGUARD_PERMISSION, calling_pid, calling_uid)) { |
| ALOGE("%s: permission denied for [%d:%d]", __func__, calling_pid, calling_uid); |
| return Status::ok(); |
| } |
| clear_sid(userId); |
| |
| uint32_t hw_userId = adjust_userId(userId); |
| if (aidl_hw_device) { |
| aidl_hw_device->deleteUser(hw_userId); |
| } else if (hw_device) { |
| hw_device->deleteUser(hw_userId, [](const GatekeeperResponse&) {}); |
| } |
| return Status::ok(); |
| } |
| |
| Status GateKeeperProxy::reportDeviceSetupComplete() { |
| IPCThreadState* ipc = IPCThreadState::self(); |
| const int calling_pid = ipc->getCallingPid(); |
| const int calling_uid = ipc->getCallingUid(); |
| if (!PermissionCache::checkPermission(KEYGUARD_PERMISSION, calling_pid, calling_uid)) { |
| ALOGE("%s: permission denied for [%d:%d]", __func__, calling_pid, calling_uid); |
| return Status::ok(); |
| } |
| |
| clear_state_if_needed(); |
| return Status::ok(); |
| } |
| |
| status_t GateKeeperProxy::dump(int fd, const Vector<String16>&) { |
| IPCThreadState* ipc = IPCThreadState::self(); |
| const int pid = ipc->getCallingPid(); |
| const int uid = ipc->getCallingUid(); |
| if (!PermissionCache::checkPermission(DUMP_PERMISSION, pid, uid)) { |
| return PERMISSION_DENIED; |
| } |
| |
| if (aidl_hw_device == nullptr && hw_device == nullptr) { |
| const char* result = "Device not available"; |
| write(fd, result, strlen(result) + 1); |
| } else { |
| const char* result = "OK"; |
| write(fd, result, strlen(result) + 1); |
| } |
| |
| return OK; |
| } |
| } // namespace android |