|  | // | 
|  | // Copyright (C) 2011 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 "update_engine/cros/omaha_response_handler_action.h" | 
|  |  | 
|  | #include <limits> | 
|  | #include <string> | 
|  |  | 
|  | #include <base/logging.h> | 
|  | #include <base/strings/string_number_conversions.h> | 
|  | #include <base/version.h> | 
|  | #include <policy/device_policy.h> | 
|  |  | 
|  | #include "update_engine/common/constants.h" | 
|  | #include "update_engine/common/hardware_interface.h" | 
|  | #include "update_engine/common/prefs_interface.h" | 
|  | #include "update_engine/common/system_state.h" | 
|  | #include "update_engine/common/utils.h" | 
|  | #include "update_engine/cros/connection_manager_interface.h" | 
|  | #include "update_engine/cros/omaha_request_params.h" | 
|  | #include "update_engine/cros/payload_state_interface.h" | 
|  | #include "update_engine/payload_consumer/delta_performer.h" | 
|  | #include "update_engine/update_manager/policy.h" | 
|  | #include "update_engine/update_manager/update_manager.h" | 
|  |  | 
|  | using chromeos_update_manager::kRollforwardInfinity; | 
|  | using chromeos_update_manager::Policy; | 
|  | using chromeos_update_manager::UpdateManager; | 
|  | using std::numeric_limits; | 
|  | using std::string; | 
|  |  | 
|  | namespace chromeos_update_engine { | 
|  |  | 
|  | OmahaResponseHandlerAction::OmahaResponseHandlerAction() | 
|  | : deadline_file_(constants::kOmahaResponseDeadlineFile) {} | 
|  |  | 
|  | void OmahaResponseHandlerAction::PerformAction() { | 
|  | CHECK(HasInputObject()); | 
|  | ScopedActionCompleter completer(processor_, this); | 
|  | const OmahaResponse& response = GetInputObject(); | 
|  | if (!response.update_exists) { | 
|  | LOG(INFO) << "There are no updates. Aborting."; | 
|  | completer.set_code(ErrorCode::kNoUpdate); | 
|  | return; | 
|  | } | 
|  |  | 
|  | // All decisions as to which URL should be used have already been done. So, | 
|  | // make the current URL as the download URL. | 
|  | string current_url = SystemState::Get()->payload_state()->GetCurrentUrl(); | 
|  | if (current_url.empty()) { | 
|  | // This shouldn't happen as we should always supply the HTTPS backup URL. | 
|  | // Handling this anyway, just in case. | 
|  | LOG(ERROR) << "There are no suitable URLs in the response to use."; | 
|  | completer.set_code(ErrorCode::kOmahaResponseInvalid); | 
|  | return; | 
|  | } | 
|  |  | 
|  | // This is the url to the first package, not all packages. | 
|  | // (For updates): All |Action|s prior to this must pass in non-excluded URLs | 
|  | // within the |OmahaResponse|, reference exlusion logic in | 
|  | // |OmahaRequestAction| and keep the enforcement of exclusions for updates. | 
|  | install_plan_.download_url = current_url; | 
|  | install_plan_.version = response.version; | 
|  |  | 
|  | OmahaRequestParams* const params = SystemState::Get()->request_params(); | 
|  | PayloadStateInterface* const payload_state = | 
|  | SystemState::Get()->payload_state(); | 
|  |  | 
|  | // If we're using p2p to download and there is a local peer, use it. | 
|  | if (payload_state->GetUsingP2PForDownloading() && | 
|  | !payload_state->GetP2PUrl().empty()) { | 
|  | LOG(INFO) << "Replacing URL " << install_plan_.download_url | 
|  | << " with local URL " << payload_state->GetP2PUrl() | 
|  | << " since p2p is enabled."; | 
|  | install_plan_.download_url = payload_state->GetP2PUrl(); | 
|  | payload_state->SetUsingP2PForDownloading(true); | 
|  | } | 
|  |  | 
|  | // Fill up the other properties based on the response. | 
|  | string update_check_response_hash; | 
|  | for (const auto& package : response.packages) { | 
|  | brillo::Blob raw_hash; | 
|  | if (!base::HexStringToBytes(package.hash, &raw_hash)) { | 
|  | LOG(ERROR) << "Failed to convert payload hash from hex string to bytes: " | 
|  | << package.hash; | 
|  | completer.set_code(ErrorCode::kOmahaResponseInvalid); | 
|  | return; | 
|  | } | 
|  | install_plan_.payloads.push_back( | 
|  | {.payload_urls = package.payload_urls, | 
|  | .size = package.size, | 
|  | .metadata_size = package.metadata_size, | 
|  | .metadata_signature = package.metadata_signature, | 
|  | .hash = raw_hash, | 
|  | .type = package.is_delta ? InstallPayloadType::kDelta | 
|  | : InstallPayloadType::kFull, | 
|  | .fp = package.fp, | 
|  | .app_id = package.app_id}); | 
|  | update_check_response_hash += package.hash + ":"; | 
|  | } | 
|  | install_plan_.public_key_rsa = response.public_key_rsa; | 
|  | install_plan_.hash_checks_mandatory = AreHashChecksMandatory(response); | 
|  | install_plan_.is_resume = DeltaPerformer::CanResumeUpdate( | 
|  | SystemState::Get()->prefs(), update_check_response_hash); | 
|  | if (install_plan_.is_resume) { | 
|  | payload_state->UpdateResumed(); | 
|  | } else { | 
|  | payload_state->UpdateRestarted(); | 
|  | LOG_IF(WARNING, | 
|  | !DeltaPerformer::ResetUpdateProgress(SystemState::Get()->prefs(), | 
|  | false)) | 
|  | << "Unable to reset the update progress."; | 
|  | LOG_IF(WARNING, | 
|  | !SystemState::Get()->prefs()->SetString( | 
|  | kPrefsUpdateCheckResponseHash, update_check_response_hash)) | 
|  | << "Unable to save the update check response hash."; | 
|  | } | 
|  |  | 
|  | if (params->is_install()) { | 
|  | install_plan_.target_slot = | 
|  | SystemState::Get()->boot_control()->GetCurrentSlot(); | 
|  | install_plan_.source_slot = BootControlInterface::kInvalidSlot; | 
|  | } else { | 
|  | install_plan_.source_slot = | 
|  | SystemState::Get()->boot_control()->GetCurrentSlot(); | 
|  | install_plan_.target_slot = install_plan_.source_slot == 0 ? 1 : 0; | 
|  | } | 
|  |  | 
|  | // The Omaha response doesn't include the channel name for this image, so we | 
|  | // use the download_channel we used during the request to tag the target slot. | 
|  | // This will be used in the next boot to know the channel the image was | 
|  | // downloaded from. | 
|  | string current_channel_key = | 
|  | kPrefsChannelOnSlotPrefix + std::to_string(install_plan_.target_slot); | 
|  | SystemState::Get()->prefs()->SetString(current_channel_key, | 
|  | params->download_channel()); | 
|  |  | 
|  | // Checking whether device is able to boot up the returned rollback image. | 
|  | if (response.is_rollback) { | 
|  | if (!params->rollback_allowed()) { | 
|  | LOG(ERROR) << "Received rollback image but rollback is not allowed."; | 
|  | completer.set_code(ErrorCode::kOmahaResponseInvalid); | 
|  | return; | 
|  | } | 
|  |  | 
|  | // Calculate the values on the version values on current device. | 
|  | auto min_kernel_key_version = static_cast<uint32_t>( | 
|  | SystemState::Get()->hardware()->GetMinKernelKeyVersion()); | 
|  | auto min_firmware_key_version = static_cast<uint32_t>( | 
|  | SystemState::Get()->hardware()->GetMinFirmwareKeyVersion()); | 
|  |  | 
|  | uint32_t kernel_key_version = | 
|  | static_cast<uint32_t>(response.rollback_key_version.kernel_key) << 16 | | 
|  | static_cast<uint32_t>(response.rollback_key_version.kernel); | 
|  | uint32_t firmware_key_version = | 
|  | static_cast<uint32_t>(response.rollback_key_version.firmware_key) | 
|  | << 16 | | 
|  | static_cast<uint32_t>(response.rollback_key_version.firmware); | 
|  |  | 
|  | LOG(INFO) << "Rollback image versions:" | 
|  | << " device_kernel_key_version=" << min_kernel_key_version | 
|  | << " image_kernel_key_version=" << kernel_key_version | 
|  | << " device_firmware_key_version=" << min_firmware_key_version | 
|  | << " image_firmware_key_version=" << firmware_key_version; | 
|  |  | 
|  | // Don't attempt a rollback if the versions are incompatible or the | 
|  | // target image does not specify the version information. | 
|  | if (kernel_key_version == numeric_limits<uint32_t>::max() || | 
|  | firmware_key_version == numeric_limits<uint32_t>::max() || | 
|  | kernel_key_version < min_kernel_key_version || | 
|  | firmware_key_version < min_firmware_key_version) { | 
|  | LOG(ERROR) << "Device won't be able to boot up the rollback image."; | 
|  | completer.set_code(ErrorCode::kRollbackNotPossible); | 
|  | return; | 
|  | } | 
|  | install_plan_.is_rollback = true; | 
|  | install_plan_.rollback_data_save_requested = | 
|  | params->rollback_data_save_requested(); | 
|  | } | 
|  |  | 
|  | // Powerwash if either the response requires it or the parameters indicated | 
|  | // powerwash (usually because there was a channel downgrade) and we are | 
|  | // downgrading the version. Enterprise rollback, indicated by | 
|  | // |response.is_rollback| is dealt with separately above. | 
|  | if (response.powerwash_required) { | 
|  | install_plan_.powerwash_required = true; | 
|  | } else if (params->ShouldPowerwash() && !response.is_rollback) { | 
|  | base::Version new_version(response.version); | 
|  | base::Version current_version(params->app_version()); | 
|  |  | 
|  | if (!new_version.IsValid()) { | 
|  | LOG(WARNING) << "Not powerwashing," | 
|  | << " the update's version number is unreadable." | 
|  | << " Update's version number: " << response.version; | 
|  | } else if (!current_version.IsValid()) { | 
|  | LOG(WARNING) << "Not powerwashing," | 
|  | << " the current version number is unreadable." | 
|  | << " Current version number: " << params->app_version(); | 
|  | } else if (new_version < current_version) { | 
|  | install_plan_.powerwash_required = true; | 
|  | // Always try to preserve enrollment and wifi data for enrolled devices. | 
|  | install_plan_.rollback_data_save_requested = | 
|  | SystemState::Get()->device_policy() && | 
|  | SystemState::Get()->device_policy()->IsEnterpriseEnrolled(); | 
|  | } | 
|  | } | 
|  |  | 
|  | TEST_AND_RETURN(HasOutputPipe()); | 
|  | if (HasOutputPipe()) | 
|  | SetOutputObject(install_plan_); | 
|  | install_plan_.Dump(); | 
|  |  | 
|  | // Send the deadline data (if any) to Chrome through a file. This is a pretty | 
|  | // hacky solution but should be OK for now. | 
|  | // | 
|  | // TODO(petkov): Re-architect this to avoid communication through a | 
|  | // file. Ideally, we would include this information in D-Bus's GetStatus | 
|  | // method and UpdateStatus signal. A potential issue is that update_engine may | 
|  | // be unresponsive during an update download. | 
|  | if (!deadline_file_.empty()) { | 
|  | if (payload_state->GetRollbackHappened()) { | 
|  | // Don't do forced update if rollback has happened since the last update | 
|  | // check where policy was present. | 
|  | LOG(INFO) << "Not forcing update because a rollback happened."; | 
|  | utils::WriteFile(deadline_file_.c_str(), nullptr, 0); | 
|  | } else { | 
|  | utils::WriteFile(deadline_file_.c_str(), | 
|  | response.deadline.data(), | 
|  | response.deadline.size()); | 
|  | } | 
|  | chmod(deadline_file_.c_str(), S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); | 
|  | } | 
|  |  | 
|  | // Check the generated install-plan with the Policy to confirm that | 
|  | // it can be applied at this time (or at all). | 
|  | UpdateManager* const update_manager = SystemState::Get()->update_manager(); | 
|  | CHECK(update_manager); | 
|  | auto ec = ErrorCode::kSuccess; | 
|  | update_manager->PolicyRequest( | 
|  | &Policy::UpdateCanBeApplied, &ec, &install_plan_); | 
|  | completer.set_code(ec); | 
|  |  | 
|  | const auto allowed_milestones = params->rollback_allowed_milestones(); | 
|  | if (allowed_milestones > 0) { | 
|  | auto max_firmware_rollforward = numeric_limits<uint32_t>::max(); | 
|  | auto max_kernel_rollforward = numeric_limits<uint32_t>::max(); | 
|  |  | 
|  | // Determine the version to update the max rollforward verified boot | 
|  | // value. | 
|  | OmahaResponse::RollbackKeyVersion version = | 
|  | response.past_rollback_key_version; | 
|  |  | 
|  | // Determine the max rollforward values to be set in the TPM. | 
|  | max_firmware_rollforward = static_cast<uint32_t>(version.firmware_key) | 
|  | << 16 | | 
|  | static_cast<uint32_t>(version.firmware); | 
|  | max_kernel_rollforward = static_cast<uint32_t>(version.kernel_key) << 16 | | 
|  | static_cast<uint32_t>(version.kernel); | 
|  |  | 
|  | // In the case that the value is 0xffffffff, log a warning because the | 
|  | // device should not be installing a rollback image without having version | 
|  | // information. | 
|  | if (max_firmware_rollforward == numeric_limits<uint32_t>::max() || | 
|  | max_kernel_rollforward == numeric_limits<uint32_t>::max()) { | 
|  | LOG(WARNING) | 
|  | << "Max rollforward values were not sent in rollback response: " | 
|  | << " max_kernel_rollforward=" << max_kernel_rollforward | 
|  | << " max_firmware_rollforward=" << max_firmware_rollforward | 
|  | << " rollback_allowed_milestones=" | 
|  | << params->rollback_allowed_milestones(); | 
|  | } else { | 
|  | LOG(INFO) << "Setting the max rollforward values: " | 
|  | << " max_kernel_rollforward=" << max_kernel_rollforward | 
|  | << " max_firmware_rollforward=" << max_firmware_rollforward | 
|  | << " rollback_allowed_milestones=" | 
|  | << params->rollback_allowed_milestones(); | 
|  | SystemState::Get()->hardware()->SetMaxKernelKeyRollforward( | 
|  | max_kernel_rollforward); | 
|  | // TODO(crbug/783998): Set max firmware rollforward when implemented. | 
|  | } | 
|  | } else { | 
|  | LOG(INFO) << "Rollback is not allowed. Setting max rollforward values" | 
|  | << " to infinity"; | 
|  | // When rollback is not allowed, explicitly set the max roll forward to | 
|  | // infinity. | 
|  | SystemState::Get()->hardware()->SetMaxKernelKeyRollforward( | 
|  | kRollforwardInfinity); | 
|  | // TODO(crbug/783998): Set max firmware rollforward when implemented. | 
|  | } | 
|  | } | 
|  |  | 
|  | bool OmahaResponseHandlerAction::AreHashChecksMandatory( | 
|  | const OmahaResponse& response) { | 
|  | // We sometimes need to waive the hash checks in order to download from | 
|  | // sources that don't provide hashes, such as dev server. | 
|  | // At this point UpdateAttempter::IsAnyUpdateSourceAllowed() has already been | 
|  | // checked, so an unofficial update URL won't get this far unless it's OK to | 
|  | // use without a hash. Additionally, we want to always waive hash checks on | 
|  | // unofficial builds (i.e. dev/test images). | 
|  | // The end result is this: | 
|  | //  * Base image: | 
|  | //    - Official URLs require a hash. | 
|  | //    - Unofficial URLs only get this far if the IsAnyUpdateSourceAllowed() | 
|  | //      devmode/debugd checks pass, in which case the hash is waived. | 
|  | //  * Dev/test image: | 
|  | //    - Any URL is allowed through with no hash checking. | 
|  | if (!SystemState::Get()->request_params()->IsUpdateUrlOfficial() || | 
|  | !SystemState::Get()->hardware()->IsOfficialBuild()) { | 
|  | // Still do a hash check if a public key is included. | 
|  | if (!response.public_key_rsa.empty()) { | 
|  | // The autoupdate_CatchBadSignatures test checks for this string | 
|  | // in log-files. Keep in sync. | 
|  | LOG(INFO) << "Mandating payload hash checks since Omaha Response " | 
|  | << "for unofficial build includes public RSA key."; | 
|  | return true; | 
|  | } else { | 
|  | LOG(INFO) << "Waiving payload hash checks for unofficial update URL."; | 
|  | return false; | 
|  | } | 
|  | } | 
|  |  | 
|  | LOG(INFO) << "Mandating hash checks for official URL on official build."; | 
|  | return true; | 
|  | } | 
|  |  | 
|  | }  // namespace chromeos_update_engine |