keystore-engine/keystore_backend_binder.cpp - platform/system/security - Git at Google

 /* Copyright 2017 The Android Open Source Project
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */

 #include "keystore_backend_binder.h"

 #include <android-base/logging.h>
 #include <android/security/keystore/IKeystoreService.h>
 #include <binder/IServiceManager.h>
 #include <binder/ProcessState.h>
 #include <keystore/KeyCharacteristics.h>
 #include <keystore/KeymasterArguments.h>
 #include <keystore/KeymasterBlob.h>
 #include <keystore/KeystoreResponse.h>
 #include <keystore/OperationResult.h>
 #include <keystore/keymaster_types.h>
 #include <keystore/keystore.h>
 #include <keystore/keystore_hidl_support.h>
 #include <keystore/keystore_promises.h>
 #include <keystore/keystore_return_types.h>

 #include <future>
 #include <thread>

 using android::security::keystore::IKeystoreService;
 using namespace android;
 using keystore::hidl_vec;

 using android::hardware::keymaster::V4_0::Algorithm;
 using android::hardware::keymaster::V4_0::authorizationValue;
 using android::hardware::keymaster::V4_0::Digest;
 using android::hardware::keymaster::V4_0::KeyFormat;
 using android::hardware::keymaster::V4_0::KeyParameter;
 using android::hardware::keymaster::V4_0::KeyPurpose;
 using android::hardware::keymaster::V4_0::NullOr;
 using android::hardware::keymaster::V4_0::PaddingMode;
 using android::hardware::keymaster::V4_0::TAG_ALGORITHM;
 using android::hardware::keymaster::V4_0::TAG_DIGEST;
 using android::hardware::keymaster::V4_0::TAG_PADDING;
 using android::security::keymaster::ExportResult;
 using android::security::keymaster::KeyCharacteristics;
 using android::security::keymaster::KeymasterArguments;
 using android::security::keymaster::KeymasterBlob;
 using android::security::keymaster::OperationResult;

 using KSReturn = keystore::KeyStoreNativeReturnCode;

 namespace {
 const char keystore_service_name[] = "android.security.keystore";
 constexpr int32_t UID_SELF = -1;

 using keystore::KeyCharacteristicsPromise;
 using keystore::KeystoreExportPromise;
 using keystore::KeystoreResponsePromise;
 using keystore::OperationResultPromise;

 }  // namespace

 #define AT __func__ << ":" << __LINE__ << " "

 static NullOr<const Algorithm&> getKeyAlgoritmFromKeyCharacteristics(
     const ::android::security::keymaster::KeyCharacteristics& characteristics) {
     for (const auto& param : characteristics.hardwareEnforced.getParameters()) {
         auto algo = authorizationValue(TAG_ALGORITHM, param);
         if (algo.isOk()) return algo;
     }
     for (const auto& param : characteristics.softwareEnforced.getParameters()) {
         auto algo = authorizationValue(TAG_ALGORITHM, param);
         if (algo.isOk()) return algo;
     }
     return {};
 }

 KeystoreBackendBinder::KeystoreBackendBinder() {
     android::ProcessState::self()->startThreadPool();
 }

 int32_t KeystoreBackendBinder::sign(const char* key_id, const uint8_t* in, size_t len,
                                     uint8_t** reply, size_t* reply_len) {
     sp<IServiceManager> sm = defaultServiceManager();
     sp<IBinder> binder = sm->getService(String16(keystore_service_name));
     sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);

     if (service == nullptr) {
         LOG(ERROR) << AT << "could not contact keystore";
         return -1;
     }

     String16 key_name16(key_id);
     int32_t error_code;
     android::sp<KeyCharacteristicsPromise> kc_promise(new KeyCharacteristicsPromise);
     auto kc_future = kc_promise->get_future();
     auto binder_result = service->getKeyCharacteristics(kc_promise, key_name16, KeymasterBlob(),
                                                         KeymasterBlob(), UID_SELF, &error_code);
     if (!binder_result.isOk()) {
         LOG(ERROR) << AT << "communication error while calling keystore";
         return -1;
     }
     if (!KSReturn(error_code).isOk()) {
         LOG(ERROR) << AT << "getKeyCharacteristics failed: " << error_code;
         return -1;
     }

     auto [km_response, characteristics] = kc_future.get();

     if (!KSReturn(km_response.response_code()).isOk()) {
         LOG(ERROR) << AT << "getKeyCharacteristics failed: " << km_response.response_code();
         return -1;
     }

     auto algorithm = getKeyAlgoritmFromKeyCharacteristics(characteristics);
     if (!algorithm.isOk()) {
         LOG(ERROR) << AT << "could not get algorithm from key characteristics";
         return -1;
     }

     hidl_vec<KeyParameter> params(3);
     params[0] = Authorization(TAG_DIGEST, Digest::NONE);
     params[1] = Authorization(TAG_PADDING, PaddingMode::NONE);
     params[2] = Authorization(TAG_ALGORITHM, algorithm.value());

     android::sp<android::IBinder> token(new android::BBinder);
     sp<OperationResultPromise> promise(new OperationResultPromise());
     auto future = promise->get_future();
     binder_result = service->begin(promise, token, key_name16, (int)KeyPurpose::SIGN,
                                    true /*pruneable*/, KeymasterArguments(params),
                                    std::vector<uint8_t>() /* entropy */, UID_SELF, &error_code);
     if (!binder_result.isOk()) {
         LOG(ERROR) << AT << "communication error while calling keystore";
         return -1;
     }

     keystore::KeyStoreNativeReturnCode rc(error_code);
     if (!rc.isOk()) {
         LOG(ERROR) << AT << "Keystore begin returned: " << error_code;
         return -1;
     }
     OperationResult result = future.get();

     if (!result.resultCode.isOk()) {
         LOG(ERROR) << AT << "begin failed: " << result.resultCode;
         return -1;
     }
     auto handle = std::move(result.token);

     do {
         future = {};
         promise = new OperationResultPromise();
         future = promise->get_future();
         binder_result = service->update(promise, handle, KeymasterArguments(params),
                                         std::vector<uint8_t>(in, in + len), &error_code);
         if (!binder_result.isOk()) {
             LOG(ERROR) << AT << "communication error while calling keystore";
             return -1;
         }

         rc = keystore::KeyStoreNativeReturnCode(error_code);
         if (!rc.isOk()) {
             LOG(ERROR) << AT << "Keystore update returned: " << error_code;
             return -1;
         }
         result = future.get();

         if (!result.resultCode.isOk()) {
             LOG(ERROR) << AT << "update failed: " << result.resultCode;
             return -1;
         }

         if (result.inputConsumed > len) {
             LOG(ERROR) << AT << "update consumed more data than provided";
             sp<KeystoreResponsePromise> abortPromise(new KeystoreResponsePromise);
             auto abortFuture = abortPromise->get_future();
             binder_result = service->abort(abortPromise, handle, &error_code);
             if (!binder_result.isOk()) {
                 LOG(ERROR) << AT << "communication error while calling keystore";
                 return -1;
             }
             // This is mainly for logging since we already failed.
             // But if abort returned OK we have to wait untill abort calls the callback
             // hence the call to abortFuture.get().
             if (!KSReturn(error_code).isOk()) {
                 LOG(ERROR) << AT << "abort failed: " << error_code;
             } else if (!(rc = KSReturn(abortFuture.get().response_code())).isOk()) {
                 LOG(ERROR) << AT << "abort failed: " << rc;
             }
             return -1;
         }
         len -= result.inputConsumed;
         in += result.inputConsumed;
     } while (len > 0);

     future = {};
     promise = new OperationResultPromise();
     future = promise->get_future();

     binder_result = service->finish(promise, handle, KeymasterArguments(params),
                                     std::vector<uint8_t>() /* signature */,
                                     std::vector<uint8_t>() /* entropy */, &error_code);

     if (!binder_result.isOk()) {
         LOG(ERROR) << AT << "communication error while calling keystore";
         return -1;
     }

     rc = keystore::KeyStoreNativeReturnCode(error_code);
     if (!rc.isOk()) {
         LOG(ERROR) << AT << "Keystore finish returned: " << error_code;
         return -1;
     }
     result = future.get();

     if (!result.resultCode.isOk()) {
         LOG(ERROR) << AT << "finish failed: " << result.resultCode;
         return -1;
     }

     hidl_vec<uint8_t> reply_hidl(result.data);
     if (reply_len) {
         *reply_len = reply_hidl.size();
     }
     if (reply) {
         *reply = reply_hidl.releaseData();
     }
     return 0;
 }

 int32_t KeystoreBackendBinder::get_pubkey(const char* key_id, uint8_t** pubkey,
                                           size_t* pubkey_len) {
     sp<IServiceManager> sm = defaultServiceManager();
     sp<IBinder> binder = sm->getService(String16(keystore_service_name));
     sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);

     if (service == nullptr) {
         LOG(ERROR) << AT << "could not contact keystore";
         return -1;
     }

     int32_t error_code;
     android::sp<KeystoreExportPromise> promise(new KeystoreExportPromise);
     auto future = promise->get_future();
     auto binder_result = service->exportKey(
         promise, String16(key_id), static_cast<int32_t>(KeyFormat::X509),
         KeymasterBlob() /* clientId */, KeymasterBlob() /* appData */, UID_SELF, &error_code);
     if (!binder_result.isOk()) {
         LOG(ERROR) << AT << "communication error while calling keystore";
         return -1;
     }

     KSReturn rc(error_code);
     if (!rc.isOk()) {
         LOG(ERROR) << AT << "exportKey failed: " << error_code;
         return -1;
     }

     auto export_result = future.get();
     if (!export_result.resultCode.isOk()) {
         LOG(ERROR) << AT << "exportKey failed: " << export_result.resultCode;
         return -1;
     }

     if (pubkey_len) {
         *pubkey_len = export_result.exportData.size();
     }
     if (pubkey) {
         *pubkey = export_result.exportData.releaseData();
     }
     return 0;
 }
	/* Copyright 2017 The Android Open Source Project
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */

	#include "keystore_backend_binder.h"

	#include <android-base/logging.h>
	#include <android/security/keystore/IKeystoreService.h>
	#include <binder/IServiceManager.h>
	#include <binder/ProcessState.h>
	#include <keystore/KeyCharacteristics.h>
	#include <keystore/KeymasterArguments.h>
	#include <keystore/KeymasterBlob.h>
	#include <keystore/KeystoreResponse.h>
	#include <keystore/OperationResult.h>
	#include <keystore/keymaster_types.h>
	#include <keystore/keystore.h>
	#include <keystore/keystore_hidl_support.h>
	#include <keystore/keystore_promises.h>
	#include <keystore/keystore_return_types.h>

	#include <future>
	#include <thread>

	using android::security::keystore::IKeystoreService;
	using namespace android;
	using keystore::hidl_vec;

	using android::hardware::keymaster::V4_0::Algorithm;
	using android::hardware::keymaster::V4_0::authorizationValue;
	using android::hardware::keymaster::V4_0::Digest;
	using android::hardware::keymaster::V4_0::KeyFormat;
	using android::hardware::keymaster::V4_0::KeyParameter;
	using android::hardware::keymaster::V4_0::KeyPurpose;
	using android::hardware::keymaster::V4_0::NullOr;
	using android::hardware::keymaster::V4_0::PaddingMode;
	using android::hardware::keymaster::V4_0::TAG_ALGORITHM;
	using android::hardware::keymaster::V4_0::TAG_DIGEST;
	using android::hardware::keymaster::V4_0::TAG_PADDING;
	using android::security::keymaster::ExportResult;
	using android::security::keymaster::KeyCharacteristics;
	using android::security::keymaster::KeymasterArguments;
	using android::security::keymaster::KeymasterBlob;
	using android::security::keymaster::OperationResult;

	using KSReturn = keystore::KeyStoreNativeReturnCode;

	namespace {
	const char keystore_service_name[] = "android.security.keystore";
	constexpr int32_t UID_SELF = -1;

	using keystore::KeyCharacteristicsPromise;
	using keystore::KeystoreExportPromise;
	using keystore::KeystoreResponsePromise;
	using keystore::OperationResultPromise;

	} // namespace

	#define AT __func__ << ":" << __LINE__ << " "

	static NullOr<const Algorithm&> getKeyAlgoritmFromKeyCharacteristics(
	const ::android::security::keymaster::KeyCharacteristics& characteristics) {
	for (const auto& param : characteristics.hardwareEnforced.getParameters()) {
	auto algo = authorizationValue(TAG_ALGORITHM, param);
	if (algo.isOk()) return algo;
	}
	for (const auto& param : characteristics.softwareEnforced.getParameters()) {
	auto algo = authorizationValue(TAG_ALGORITHM, param);
	if (algo.isOk()) return algo;
	}
	return {};
	}

	KeystoreBackendBinder::KeystoreBackendBinder() {
	android::ProcessState::self()->startThreadPool();
	}

	int32_t KeystoreBackendBinder::sign(const char* key_id, const uint8_t* in, size_t len,
	uint8_t** reply, size_t* reply_len) {
	sp<IServiceManager> sm = defaultServiceManager();
	sp<IBinder> binder = sm->getService(String16(keystore_service_name));
	sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);

	if (service == nullptr) {
	LOG(ERROR) << AT << "could not contact keystore";
	return -1;
	}

	String16 key_name16(key_id);
	int32_t error_code;
	android::sp<KeyCharacteristicsPromise> kc_promise(new KeyCharacteristicsPromise);
	auto kc_future = kc_promise->get_future();
	auto binder_result = service->getKeyCharacteristics(kc_promise, key_name16, KeymasterBlob(),
	KeymasterBlob(), UID_SELF, &error_code);
	if (!binder_result.isOk()) {
	LOG(ERROR) << AT << "communication error while calling keystore";
	return -1;
	}
	if (!KSReturn(error_code).isOk()) {
	LOG(ERROR) << AT << "getKeyCharacteristics failed: " << error_code;
	return -1;
	}

	auto [km_response, characteristics] = kc_future.get();

	if (!KSReturn(km_response.response_code()).isOk()) {
	LOG(ERROR) << AT << "getKeyCharacteristics failed: " << km_response.response_code();
	return -1;
	}

	auto algorithm = getKeyAlgoritmFromKeyCharacteristics(characteristics);
	if (!algorithm.isOk()) {
	LOG(ERROR) << AT << "could not get algorithm from key characteristics";
	return -1;
	}

	hidl_vec<KeyParameter> params(3);
	params[0] = Authorization(TAG_DIGEST, Digest::NONE);
	params[1] = Authorization(TAG_PADDING, PaddingMode::NONE);
	params[2] = Authorization(TAG_ALGORITHM, algorithm.value());

	android::sp<android::IBinder> token(new android::BBinder);
	sp<OperationResultPromise> promise(new OperationResultPromise());
	auto future = promise->get_future();
	binder_result = service->begin(promise, token, key_name16, (int)KeyPurpose::SIGN,
	true /pruneable/, KeymasterArguments(params),
	std::vector<uint8_t>() /* entropy */, UID_SELF, &error_code);
	if (!binder_result.isOk()) {
	LOG(ERROR) << AT << "communication error while calling keystore";
	return -1;
	}

	keystore::KeyStoreNativeReturnCode rc(error_code);
	if (!rc.isOk()) {
	LOG(ERROR) << AT << "Keystore begin returned: " << error_code;
	return -1;
	}
	OperationResult result = future.get();

	if (!result.resultCode.isOk()) {
	LOG(ERROR) << AT << "begin failed: " << result.resultCode;
	return -1;
	}
	auto handle = std::move(result.token);

	do {
	future = {};
	promise = new OperationResultPromise();
	future = promise->get_future();
	binder_result = service->update(promise, handle, KeymasterArguments(params),
	std::vector<uint8_t>(in, in + len), &error_code);
	if (!binder_result.isOk()) {
	LOG(ERROR) << AT << "communication error while calling keystore";
	return -1;
	}

	rc = keystore::KeyStoreNativeReturnCode(error_code);
	if (!rc.isOk()) {
	LOG(ERROR) << AT << "Keystore update returned: " << error_code;
	return -1;
	}
	result = future.get();

	if (!result.resultCode.isOk()) {
	LOG(ERROR) << AT << "update failed: " << result.resultCode;
	return -1;
	}

	if (result.inputConsumed > len) {
	LOG(ERROR) << AT << "update consumed more data than provided";
	sp<KeystoreResponsePromise> abortPromise(new KeystoreResponsePromise);
	auto abortFuture = abortPromise->get_future();
	binder_result = service->abort(abortPromise, handle, &error_code);
	if (!binder_result.isOk()) {
	LOG(ERROR) << AT << "communication error while calling keystore";
	return -1;
	}
	// This is mainly for logging since we already failed.
	// But if abort returned OK we have to wait untill abort calls the callback
	// hence the call to abortFuture.get().
	if (!KSReturn(error_code).isOk()) {
	LOG(ERROR) << AT << "abort failed: " << error_code;
	} else if (!(rc = KSReturn(abortFuture.get().response_code())).isOk()) {
	LOG(ERROR) << AT << "abort failed: " << rc;
	}
	return -1;
	}
	len -= result.inputConsumed;
	in += result.inputConsumed;
	} while (len > 0);

	future = {};
	promise = new OperationResultPromise();
	future = promise->get_future();

	binder_result = service->finish(promise, handle, KeymasterArguments(params),
	std::vector<uint8_t>() /* signature */,
	std::vector<uint8_t>() /* entropy */, &error_code);

	if (!binder_result.isOk()) {
	LOG(ERROR) << AT << "communication error while calling keystore";
	return -1;
	}

	rc = keystore::KeyStoreNativeReturnCode(error_code);
	if (!rc.isOk()) {
	LOG(ERROR) << AT << "Keystore finish returned: " << error_code;
	return -1;
	}
	result = future.get();

	if (!result.resultCode.isOk()) {
	LOG(ERROR) << AT << "finish failed: " << result.resultCode;
	return -1;
	}

	hidl_vec<uint8_t> reply_hidl(result.data);
	if (reply_len) {
	*reply_len = reply_hidl.size();
	}
	if (reply) {
	*reply = reply_hidl.releaseData();
	}
	return 0;
	}

	int32_t KeystoreBackendBinder::get_pubkey(const char* key_id, uint8_t** pubkey,
	size_t* pubkey_len) {
	sp<IServiceManager> sm = defaultServiceManager();
	sp<IBinder> binder = sm->getService(String16(keystore_service_name));
	sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);

	if (service == nullptr) {
	LOG(ERROR) << AT << "could not contact keystore";
	return -1;
	}

	int32_t error_code;
	android::sp<KeystoreExportPromise> promise(new KeystoreExportPromise);
	auto future = promise->get_future();
	auto binder_result = service->exportKey(
	promise, String16(key_id), static_cast<int32_t>(KeyFormat::X509),
	KeymasterBlob() /* clientId /, KeymasterBlob() / appData */, UID_SELF, &error_code);
	if (!binder_result.isOk()) {
	LOG(ERROR) << AT << "communication error while calling keystore";
	return -1;
	}

	KSReturn rc(error_code);
	if (!rc.isOk()) {
	LOG(ERROR) << AT << "exportKey failed: " << error_code;
	return -1;
	}

	auto export_result = future.get();
	if (!export_result.resultCode.isOk()) {
	LOG(ERROR) << AT << "exportKey failed: " << export_result.resultCode;
	return -1;
	}

	if (pubkey_len) {
	*pubkey_len = export_result.exportData.size();
	}
	if (pubkey) {
	*pubkey = export_result.exportData.releaseData();
	}
	return 0;
	}