| /* 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>() /* input */, | 
 |         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; | 
 | } |