/*    Copyright 2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects
 *    for all of the code used other than as permitted herein. If you modify
 *    file(s) with this exception, you may extend this exception to your
 *    version of the file(s), but you are not obligated to do so. If you do not
 *    wish to do so, delete this exception statement from your version. If you
 *    delete this exception statement from all source files in the program,
 *    then also delete it in the license file.
 */

#include "mongo/platform/basic.h"

#include "mongo/client/native_sasl_client_session.h"

#include "mongo/base/init.h"
#include "mongo/client/sasl_client_conversation.h"
#include "mongo/client/sasl_plain_client_conversation.h"
#include "mongo/client/sasl_scram_client_conversation.h"
#include "mongo/client/scram_client_cache.h"
#include "mongo/util/mongoutils/str.h"

namespace mongo {
namespace {

SaslClientSession* createNativeSaslClientSession(const std::string mech) {
    return new NativeSaslClientSession();
}

MONGO_INITIALIZER(NativeSaslClientContext)(InitializerContext* context) {
    SaslClientSession::create = createNativeSaslClientSession;
    return Status::OK();
}

// Global cache for SCRAM-SHA-1/256 credentials
auto* scramsha1ClientCache = new SCRAMClientCache<SHA1Block>;
auto* scramsha256ClientCache = new SCRAMClientCache<SHA256Block>;

}  // namespace

NativeSaslClientSession::NativeSaslClientSession()
    : SaslClientSession(), _step(0), _done(false), _saslConversation(nullptr) {}

NativeSaslClientSession::~NativeSaslClientSession() {}

Status NativeSaslClientSession::initialize() {
    if (_saslConversation)
        return Status(ErrorCodes::AlreadyInitialized,
                      "Cannot reinitialize NativeSaslClientSession.");

    std::string mechanism = getParameter(parameterMechanism).toString();
    if (mechanism == "PLAIN") {
        _saslConversation.reset(new SaslPLAINClientConversation(this));
    } else if (mechanism == "SCRAM-SHA-1") {
        _saslConversation.reset(
            new SaslSCRAMClientConversationImpl<SHA1Block>(this, scramsha1ClientCache));
    } else if (mechanism == "SCRAM-SHA-256") {
        _saslConversation.reset(
            new SaslSCRAMClientConversationImpl<SHA256Block>(this, scramsha256ClientCache));
    } else {
        return Status(ErrorCodes::BadValue,
                      mongoutils::str::stream() << "SASL mechanism " << mechanism
                                                << " is not supported");
    }

    return Status::OK();
}

Status NativeSaslClientSession::step(StringData inputData, std::string* outputData) {
    if (!_saslConversation) {
        return Status(ErrorCodes::BadValue,
                      mongoutils::str::stream()
                          << "The client authentication session has not been properly initialized");
    }

    StatusWith<bool> status = _saslConversation->step(inputData, outputData);
    if (status.isOK()) {
        _done = status.getValue();
    }
    return status.getStatus();
}
}  // namespace