platform_system_security/keystore-engine/keystore_backend_binder.cpp
Rob Barnes 3af223fde0 Allow for input_data on finish.
Test: Keystore CTS tests

Change-Id: I22e69079e3ad5462ded2c7b71274c29ba5ef58d0
2019-11-14 16:43:12 -07:00

286 lines
11 KiB
C++

/* 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;
}