Create a KeystoreClient class.

KeystoreClient is designed to give native brillo services convenient
access to keystore services. This CL also includes a command line tool
that uses the KeystoreClient interface. This was used for testing but
can also be enhanced to be generally useful.

BUG: 23528174
TEST=manual tests using keystore_cli_v2

Change-Id: I6266d98cfc7c4936f803a8133020c032bc519a5b
diff --git a/keystore/keystore_client_impl.cpp b/keystore/keystore_client_impl.cpp
new file mode 100644
index 0000000..deaa615
--- /dev/null
+++ b/keystore/keystore_client_impl.cpp
@@ -0,0 +1,251 @@
+// Copyright 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.
+
+#include "keystore/keystore_client_impl.h"
+
+#include <string>
+#include <vector>
+
+#include "binder/IBinder.h"
+#include "binder/IInterface.h"
+#include "binder/IServiceManager.h"
+#include "keystore/IKeystoreService.h"
+#include "keystore/keystore.h"
+#include "utils/String16.h"
+#include "utils/String8.h"
+
+using android::ExportResult;
+using android::KeyCharacteristics;
+using android::KeymasterArguments;
+using android::OperationResult;
+using android::String16;
+using keymaster::AuthorizationSet;
+
+namespace {
+
+// Use the UID of the current process.
+const int kDefaultUID = -1;
+
+const uint8_t* StringAsByteArray(const std::string& s) {
+    return reinterpret_cast<const uint8_t*>(s.data());
+}
+
+std::string ByteArrayAsString(const uint8_t* data, size_t data_size) {
+    return std::string(reinterpret_cast<const char*>(data), data_size);
+}
+
+}  // namespace
+
+namespace keystore {
+
+KeystoreClientImpl::KeystoreClientImpl() {
+    service_manager_ = android::defaultServiceManager();
+    keystore_binder_ = service_manager_->getService(String16("android.security.keystore"));
+    keystore_ = android::interface_cast<android::IKeystoreService>(keystore_binder_);
+}
+
+int32_t KeystoreClientImpl::addRandomNumberGeneratorEntropy(const std::string& entropy) {
+    return mapKeystoreError(keystore_->addRngEntropy(StringAsByteArray(entropy), entropy.size()));
+}
+
+int32_t KeystoreClientImpl::generateKey(const std::string& key_name,
+                                        const AuthorizationSet& key_parameters,
+                                        AuthorizationSet* hardware_enforced_characteristics,
+                                        AuthorizationSet* software_enforced_characteristics) {
+    String16 key_name16(key_name.data(), key_name.size());
+    KeymasterArguments key_arguments;
+    key_arguments.params.assign(key_parameters.begin(), key_parameters.end());
+    KeyCharacteristics characteristics;
+    int32_t result =
+        keystore_->generateKey(key_name16, key_arguments, NULL /*entropy*/, 0 /*entropyLength*/,
+                               kDefaultUID, KEYSTORE_FLAG_NONE, &characteristics);
+    hardware_enforced_characteristics->Reinitialize(characteristics.characteristics.hw_enforced);
+    software_enforced_characteristics->Reinitialize(characteristics.characteristics.sw_enforced);
+    return mapKeystoreError(result);
+}
+
+int32_t
+KeystoreClientImpl::getKeyCharacteristics(const std::string& key_name,
+                                          AuthorizationSet* hardware_enforced_characteristics,
+                                          AuthorizationSet* software_enforced_characteristics) {
+    String16 key_name16(key_name.data(), key_name.size());
+    keymaster_blob_t client_id_blob = {nullptr, 0};
+    keymaster_blob_t app_data_blob = {nullptr, 0};
+    KeyCharacteristics characteristics;
+    int32_t result = keystore_->getKeyCharacteristics(key_name16, &client_id_blob, &app_data_blob,
+                                                      &characteristics);
+    hardware_enforced_characteristics->Reinitialize(characteristics.characteristics.hw_enforced);
+    software_enforced_characteristics->Reinitialize(characteristics.characteristics.sw_enforced);
+    return mapKeystoreError(result);
+}
+
+int32_t KeystoreClientImpl::importKey(const std::string& key_name,
+                                      const AuthorizationSet& key_parameters,
+                                      keymaster_key_format_t key_format,
+                                      const std::string& key_data,
+                                      AuthorizationSet* hardware_enforced_characteristics,
+                                      AuthorizationSet* software_enforced_characteristics) {
+    String16 key_name16(key_name.data(), key_name.size());
+    KeymasterArguments key_arguments;
+    key_arguments.params.assign(key_parameters.begin(), key_parameters.end());
+    KeyCharacteristics characteristics;
+    int32_t result =
+        keystore_->importKey(key_name16, key_arguments, key_format, StringAsByteArray(key_data),
+                             key_data.size(), kDefaultUID, KEYSTORE_FLAG_NONE, &characteristics);
+    hardware_enforced_characteristics->Reinitialize(characteristics.characteristics.hw_enforced);
+    software_enforced_characteristics->Reinitialize(characteristics.characteristics.sw_enforced);
+    return mapKeystoreError(result);
+}
+
+int32_t KeystoreClientImpl::exportKey(keymaster_key_format_t export_format,
+                                      const std::string& key_name, std::string* export_data) {
+    String16 key_name16(key_name.data(), key_name.size());
+    keymaster_blob_t client_id_blob = {nullptr, 0};
+    keymaster_blob_t app_data_blob = {nullptr, 0};
+    ExportResult export_result;
+    keystore_->exportKey(key_name16, export_format, &client_id_blob, &app_data_blob,
+                         &export_result);
+    *export_data = ByteArrayAsString(export_result.exportData.get(), export_result.dataLength);
+    return mapKeystoreError(export_result.resultCode);
+}
+
+int32_t KeystoreClientImpl::deleteKey(const std::string& key_name) {
+    String16 key_name16(key_name.data(), key_name.size());
+    return mapKeystoreError(keystore_->del(key_name16, kDefaultUID));
+}
+
+int32_t KeystoreClientImpl::deleteAllKeys() {
+    return mapKeystoreError(keystore_->clear_uid(kDefaultUID));
+}
+
+int32_t KeystoreClientImpl::beginOperation(keymaster_purpose_t purpose, const std::string& key_name,
+                                           const AuthorizationSet& input_parameters,
+                                           AuthorizationSet* output_parameters,
+                                           keymaster_operation_handle_t* handle) {
+    android::sp<android::IBinder> token(new android::BBinder);
+    String16 key_name16(key_name.data(), key_name.size());
+    KeymasterArguments input_arguments;
+    input_arguments.params.assign(input_parameters.begin(), input_parameters.end());
+    OperationResult result;
+    keystore_->begin(token, key_name16, purpose, true /*pruneable*/, input_arguments,
+                     NULL /*entropy*/, 0 /*entropyLength*/, &result);
+    int32_t error_code = mapKeystoreError(result.resultCode);
+    if (error_code == KM_ERROR_OK) {
+        *handle = getNextVirtualHandle();
+        active_operations_[*handle] = result.token;
+        if (!result.outParams.params.empty()) {
+            output_parameters->Reinitialize(&*result.outParams.params.begin(),
+                                            result.outParams.params.size());
+        }
+    }
+    return error_code;
+}
+
+int32_t KeystoreClientImpl::updateOperation(keymaster_operation_handle_t handle,
+                                            const AuthorizationSet& input_parameters,
+                                            const std::string& input_data,
+                                            size_t* num_input_bytes_consumed,
+                                            AuthorizationSet* output_parameters,
+                                            std::string* output_data) {
+    if (active_operations_.count(handle) == 0) {
+        return KM_ERROR_INVALID_OPERATION_HANDLE;
+    }
+    KeymasterArguments input_arguments;
+    input_arguments.params.assign(input_parameters.begin(), input_parameters.end());
+    OperationResult result;
+    keystore_->update(active_operations_[handle], input_arguments, StringAsByteArray(input_data),
+                      input_data.size(), &result);
+    int32_t error_code = mapKeystoreError(result.resultCode);
+    if (error_code == KM_ERROR_OK) {
+        *num_input_bytes_consumed = result.inputConsumed;
+        if (!result.outParams.params.empty()) {
+            output_parameters->Reinitialize(&*result.outParams.params.begin(),
+                                            result.outParams.params.size());
+        }
+        *output_data = ByteArrayAsString(result.data.get(), result.dataLength);
+    }
+    return error_code;
+}
+
+int32_t KeystoreClientImpl::finishOperation(keymaster_operation_handle_t handle,
+                                            const AuthorizationSet& input_parameters,
+                                            const std::string& signature_to_verify,
+                                            AuthorizationSet* output_parameters,
+                                            std::string* output_data) {
+    if (active_operations_.count(handle) == 0) {
+        return KM_ERROR_INVALID_OPERATION_HANDLE;
+    }
+    KeymasterArguments input_arguments;
+    input_arguments.params.assign(input_parameters.begin(), input_parameters.end());
+    OperationResult result;
+    keystore_->finish(active_operations_[handle], input_arguments,
+                      StringAsByteArray(signature_to_verify), signature_to_verify.size(),
+                      NULL /*entropy*/, 0 /*entropyLength*/, &result);
+    int32_t error_code = mapKeystoreError(result.resultCode);
+    if (error_code == KM_ERROR_OK) {
+        if (!result.outParams.params.empty()) {
+            output_parameters->Reinitialize(&*result.outParams.params.begin(),
+                                            result.outParams.params.size());
+        }
+        *output_data = ByteArrayAsString(result.data.get(), result.dataLength);
+        active_operations_.erase(handle);
+    }
+    return error_code;
+}
+
+int32_t KeystoreClientImpl::abortOperation(keymaster_operation_handle_t handle) {
+    if (active_operations_.count(handle) == 0) {
+        return KM_ERROR_INVALID_OPERATION_HANDLE;
+    }
+    int32_t error_code = mapKeystoreError(keystore_->abort(active_operations_[handle]));
+    if (error_code == KM_ERROR_OK) {
+        active_operations_.erase(handle);
+    }
+    return error_code;
+}
+
+bool KeystoreClientImpl::doesKeyExist(const std::string& key_name) {
+    String16 key_name16(key_name.data(), key_name.size());
+    int32_t error_code = mapKeystoreError(keystore_->exist(key_name16, kDefaultUID));
+    return (error_code == KM_ERROR_OK);
+}
+
+bool KeystoreClientImpl::listKeys(const std::string& prefix,
+                                  std::vector<std::string>* key_name_list) {
+    String16 prefix16(prefix.data(), prefix.size());
+    android::Vector<String16> matches;
+    int32_t error_code = mapKeystoreError(keystore_->list(prefix16, kDefaultUID, &matches));
+    if (error_code == KM_ERROR_OK) {
+        for (const auto& match : matches) {
+            android::String8 key_name(match);
+            key_name_list->push_back(prefix + std::string(key_name.string(), key_name.size()));
+        }
+        return true;
+    }
+    return false;
+}
+
+keymaster_operation_handle_t KeystoreClientImpl::getNextVirtualHandle() {
+    return next_virtual_handle_++;
+}
+
+int32_t KeystoreClientImpl::mapKeystoreError(int32_t keystore_error) {
+    // See notes in keystore_client.h for rationale.
+    if (keystore_error == ::NO_ERROR) {
+        return KM_ERROR_OK;
+    }
+    return keystore_error;
+}
+
+}  // namespace keystore