| /* |
| * 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 "IGateKeeperService.h" |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <inttypes.h> |
| #include <stdint.h> |
| #include <unistd.h> |
| |
| #include <binder/IPCThreadState.h> |
| #include <binder/IServiceManager.h> |
| #include <binder/PermissionCache.h> |
| #include <gatekeeper/password_handle.h> // for password_handle_t |
| #include <hardware/gatekeeper.h> |
| #include <hardware/hw_auth_token.h> |
| #include <keystore/IKeystoreService.h> |
| #include <keystore/keystore.h> // For error code |
| #include <log/log.h> |
| #include <utils/Log.h> |
| #include <utils/String16.h> |
| |
| #include "SoftGateKeeperDevice.h" |
| #include "IUserManager.h" |
| |
| namespace android { |
| |
| static const String16 KEYGUARD_PERMISSION("android.permission.ACCESS_KEYGUARD_SECURE_STORAGE"); |
| static const String16 DUMP_PERMISSION("android.permission.DUMP"); |
| |
| class GateKeeperProxy : public BnGateKeeperService { |
| public: |
| GateKeeperProxy() { |
| int ret = hw_get_module_by_class(GATEKEEPER_HARDWARE_MODULE_ID, NULL, &module); |
| device = NULL; |
| |
| if (ret < 0) { |
| ALOGW("falling back to software GateKeeper"); |
| soft_device.reset(new SoftGateKeeperDevice()); |
| } else { |
| ret = gatekeeper_open(module, &device); |
| if (ret < 0) |
| LOG_ALWAYS_FATAL_IF(ret < 0, "Unable to open GateKeeper HAL"); |
| } |
| |
| if (mark_cold_boot()) { |
| ALOGI("cold boot: clearing state"); |
| if (device != NULL && device->delete_all_users != NULL) { |
| device->delete_all_users(device); |
| } |
| } |
| } |
| |
| virtual ~GateKeeperProxy() { |
| if (device) gatekeeper_close(device); |
| } |
| |
| void store_sid(uint32_t uid, uint64_t sid) { |
| char filename[21]; |
| snprintf(filename, sizeof(filename), "%u", uid); |
| 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); |
| } |
| |
| bool 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 maybe_store_sid(uint32_t uid, uint64_t sid) { |
| char filename[21]; |
| snprintf(filename, sizeof(filename), "%u", uid); |
| if (access(filename, F_OK) == -1) { |
| store_sid(uid, sid); |
| } |
| } |
| |
| uint64_t read_sid(uint32_t uid) { |
| char filename[21]; |
| uint64_t sid; |
| snprintf(filename, sizeof(filename), "%u", uid); |
| int fd = open(filename, O_RDONLY); |
| if (fd < 0) return 0; |
| read(fd, &sid, sizeof(sid)); |
| close(fd); |
| return sid; |
| } |
| |
| void clear_sid(uint32_t uid) { |
| char filename[21]; |
| snprintf(filename, sizeof(filename), "%u", uid); |
| if (remove(filename) < 0) { |
| ALOGE("%s: could not remove file [%s], attempting 0 write", __func__, strerror(errno)); |
| store_sid(uid, 0); |
| } |
| } |
| |
| virtual int enroll(uint32_t uid, |
| const uint8_t *current_password_handle, uint32_t current_password_handle_length, |
| const uint8_t *current_password, uint32_t current_password_length, |
| const uint8_t *desired_password, uint32_t desired_password_length, |
| uint8_t **enrolled_password_handle, uint32_t *enrolled_password_handle_length) { |
| 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 PERMISSION_DENIED; |
| } |
| |
| // need a desired password to enroll |
| if (desired_password_length == 0) return -EINVAL; |
| |
| int ret; |
| if (device) { |
| const gatekeeper::password_handle_t *handle = |
| reinterpret_cast<const gatekeeper::password_handle_t *>(current_password_handle); |
| |
| if (handle != NULL && handle->version != 0 && !handle->hardware_backed) { |
| // handle is being re-enrolled from a software version. HAL probably won't accept |
| // the handle as valid, so we nullify it and enroll from scratch |
| current_password_handle = NULL; |
| current_password_handle_length = 0; |
| current_password = NULL; |
| current_password_length = 0; |
| } |
| |
| ret = device->enroll(device, uid, current_password_handle, current_password_handle_length, |
| current_password, current_password_length, |
| desired_password, desired_password_length, |
| enrolled_password_handle, enrolled_password_handle_length); |
| } else { |
| ret = soft_device->enroll(uid, |
| current_password_handle, current_password_handle_length, |
| current_password, current_password_length, |
| desired_password, desired_password_length, |
| enrolled_password_handle, enrolled_password_handle_length); |
| } |
| |
| if (ret == GATEKEEPER_RESPONSE_OK && (*enrolled_password_handle == nullptr || |
| *enrolled_password_handle_length != sizeof(password_handle_t))) { |
| ret = GATEKEEPER_RESPONSE_ERROR; |
| ALOGE("HAL: password_handle=%p size_of_handle=%" PRIu32 "\n", |
| *enrolled_password_handle, *enrolled_password_handle_length); |
| } |
| |
| if (ret == GATEKEEPER_RESPONSE_OK) { |
| gatekeeper::password_handle_t *handle = |
| reinterpret_cast<gatekeeper::password_handle_t *>(*enrolled_password_handle); |
| store_sid(uid, handle->user_id); |
| bool rr; |
| |
| // immediately verify this password so we don't ask the user to enter it again |
| // if they just created it. |
| verify(uid, *enrolled_password_handle, sizeof(password_handle_t), desired_password, |
| desired_password_length, &rr); |
| } |
| |
| return ret; |
| } |
| |
| virtual int verify(uint32_t uid, |
| const uint8_t *enrolled_password_handle, uint32_t enrolled_password_handle_length, |
| const uint8_t *provided_password, uint32_t provided_password_length, bool *request_reenroll) { |
| uint8_t *auth_token; |
| uint32_t auth_token_length; |
| return verifyChallenge(uid, 0, enrolled_password_handle, enrolled_password_handle_length, |
| provided_password, provided_password_length, |
| &auth_token, &auth_token_length, request_reenroll); |
| } |
| |
| virtual int verifyChallenge(uint32_t uid, uint64_t challenge, |
| const uint8_t *enrolled_password_handle, uint32_t enrolled_password_handle_length, |
| const uint8_t *provided_password, uint32_t provided_password_length, |
| uint8_t **auth_token, uint32_t *auth_token_length, bool *request_reenroll) { |
| 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 PERMISSION_DENIED; |
| } |
| |
| // can't verify if we're missing either param |
| if ((enrolled_password_handle_length | provided_password_length) == 0) |
| return -EINVAL; |
| |
| int ret; |
| if (device) { |
| const gatekeeper::password_handle_t *handle = |
| reinterpret_cast<const gatekeeper::password_handle_t *>(enrolled_password_handle); |
| // handle version 0 does not have hardware backed flag, and thus cannot be upgraded to |
| // a HAL if there was none before |
| if (handle->version == 0 || handle->hardware_backed) { |
| ret = device->verify(device, uid, challenge, |
| enrolled_password_handle, enrolled_password_handle_length, |
| provided_password, provided_password_length, auth_token, auth_token_length, |
| request_reenroll); |
| } else { |
| // upgrade scenario, a HAL has been added to this device where there was none before |
| SoftGateKeeperDevice soft_dev; |
| ret = soft_dev.verify(uid, challenge, |
| enrolled_password_handle, enrolled_password_handle_length, |
| provided_password, provided_password_length, auth_token, auth_token_length, |
| request_reenroll); |
| |
| if (ret == 0) { |
| // success! re-enroll with HAL |
| *request_reenroll = true; |
| } |
| } |
| } else { |
| ret = soft_device->verify(uid, challenge, |
| enrolled_password_handle, enrolled_password_handle_length, |
| provided_password, provided_password_length, auth_token, auth_token_length, |
| request_reenroll); |
| } |
| |
| if (ret == 0 && *auth_token != NULL && *auth_token_length > 0) { |
| // TODO: cache service? |
| sp<IServiceManager> sm = defaultServiceManager(); |
| sp<IBinder> binder = sm->getService(String16("android.security.keystore")); |
| sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder); |
| if (service != NULL) { |
| status_t ret = service->addAuthToken(*auth_token, *auth_token_length); |
| if (ret != ResponseCode::NO_ERROR) { |
| ALOGE("Falure sending auth token to KeyStore: %d", ret); |
| } |
| } else { |
| ALOGE("Unable to communicate with KeyStore"); |
| } |
| } |
| |
| if (ret == 0) { |
| maybe_store_sid(uid, reinterpret_cast<const gatekeeper::password_handle_t *>( |
| enrolled_password_handle)->user_id); |
| } |
| |
| return ret; |
| } |
| |
| virtual uint64_t getSecureUserId(uint32_t uid) { |
| uint64_t sid = read_sid(uid); |
| if (sid == 0) { |
| // might be a work profile, look up the parent |
| sp<IServiceManager> sm = defaultServiceManager(); |
| sp<IBinder> binder = sm->getService(String16("user")); |
| sp<IUserManager> um = interface_cast<IUserManager>(binder); |
| int32_t parent = um->getCredentialOwnerProfile(uid); |
| if (parent < 0) { |
| return 0; |
| } else if (parent != (int32_t) uid) { |
| return read_sid(parent); |
| } |
| } |
| return sid; |
| |
| } |
| |
| virtual void clearSecureUserId(uint32_t uid) { |
| 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; |
| } |
| clear_sid(uid); |
| |
| if (device != NULL && device->delete_user != NULL) { |
| device->delete_user(device, uid); |
| } |
| } |
| |
| virtual status_t 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 (device == NULL) { |
| const char *result = "Device not available"; |
| write(fd, result, strlen(result) + 1); |
| } else { |
| const char *result = "OK"; |
| write(fd, result, strlen(result) + 1); |
| } |
| |
| return NO_ERROR; |
| } |
| |
| private: |
| gatekeeper_device_t *device; |
| UniquePtr<SoftGateKeeperDevice> soft_device; |
| const hw_module_t *module; |
| }; |
| }// namespace android |
| |
| int main(int argc, char* argv[]) { |
| ALOGI("Starting gatekeeperd..."); |
| if (argc < 2) { |
| ALOGE("A directory must be specified!"); |
| return 1; |
| } |
| if (chdir(argv[1]) == -1) { |
| ALOGE("chdir: %s: %s", argv[1], strerror(errno)); |
| return 1; |
| } |
| |
| android::sp<android::IServiceManager> sm = android::defaultServiceManager(); |
| android::sp<android::GateKeeperProxy> proxy = new android::GateKeeperProxy(); |
| android::status_t ret = sm->addService( |
| android::String16("android.service.gatekeeper.IGateKeeperService"), proxy); |
| if (ret != android::OK) { |
| ALOGE("Couldn't register binder service!"); |
| return -1; |
| } |
| |
| /* |
| * We're the only thread in existence, so we're just going to process |
| * Binder transaction as a single-threaded program. |
| */ |
| android::IPCThreadState::self()->joinThreadPool(); |
| return 0; |
| } |
