/**
 *    Copyright (C) 2018 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/config.h"
#include "mongo/db/auth/internal_user_auth.h"
#include "mongo/db/auth/sasl_command_constants.h"
#include "mongo/db/server_options.h"
#include "mongo/db/server_parameters.h"
#include "mongo/util/net/ssl_manager.h"
#include "mongo/util/net/ssl_options.h"

namespace mongo {

namespace {

class SSLModeSetting : public ServerParameter {
public:
    SSLModeSetting()
        : ServerParameter(ServerParameterSet::getGlobal(),
                          "sslMode",
                          false,  // allowedToChangeAtStartup
                          true    // allowedToChangeAtRuntime
                          ) {}

    std::string sslModeStr() {
        switch (sslGlobalParams.sslMode.load()) {
            case SSLParams::SSLMode_disabled:
                return "disabled";
            case SSLParams::SSLMode_allowSSL:
                return "allowSSL";
            case SSLParams::SSLMode_preferSSL:
                return "preferSSL";
            case SSLParams::SSLMode_requireSSL:
                return "requireSSL";
            default:
                return "undefined";
        }
    }

    virtual void append(OperationContext* opCtx, BSONObjBuilder& b, const std::string& name) {
        b << name << sslModeStr();
    }

    virtual Status set(const BSONElement& newValueElement) {
        try {
            return setFromString(newValueElement.String());
        } catch (const AssertionException& msg) {
            return Status(ErrorCodes::BadValue,
                          mongoutils::str::stream()
                              << "Invalid value for sslMode via setParameter command: "
                              << newValueElement
                              << ", exception: "
                              << msg.what());
        }
    }

    virtual Status setFromString(const std::string& str) {
#ifndef MONGO_CONFIG_SSL
        return Status(ErrorCodes::IllegalOperation,
                      mongoutils::str::stream()
                          << "Unable to set sslMode, SSL support is not compiled into server");
#endif
        if (str != "disabled" && str != "allowSSL" && str != "preferSSL" && str != "requireSSL") {
            return Status(ErrorCodes::BadValue,
                          mongoutils::str::stream()
                              << "Invalid value for sslMode via setParameter command: "
                              << str);
        }

        int oldMode = sslGlobalParams.sslMode.load();
        if (str == "preferSSL" && oldMode == SSLParams::SSLMode_allowSSL) {
            sslGlobalParams.sslMode.store(SSLParams::SSLMode_preferSSL);
        } else if (str == "requireSSL" && oldMode == SSLParams::SSLMode_preferSSL) {
            sslGlobalParams.sslMode.store(SSLParams::SSLMode_requireSSL);
        } else {
            return Status(ErrorCodes::BadValue,
                          mongoutils::str::stream()
                              << "Illegal state transition for sslMode, attempt to change from "
                              << sslModeStr()
                              << " to "
                              << str);
        }
        return Status::OK();
    }
} sslModeSetting;

class ClusterAuthModeSetting : public ServerParameter {
public:
    ClusterAuthModeSetting()
        : ServerParameter(ServerParameterSet::getGlobal(),
                          "clusterAuthMode",
                          false,  // allowedToChangeAtStartup
                          true    // allowedToChangeAtRuntime
                          ) {}

    std::string clusterAuthModeStr() {
        switch (serverGlobalParams.clusterAuthMode.load()) {
            case ServerGlobalParams::ClusterAuthMode_keyFile:
                return "keyFile";
            case ServerGlobalParams::ClusterAuthMode_sendKeyFile:
                return "sendKeyFile";
            case ServerGlobalParams::ClusterAuthMode_sendX509:
                return "sendX509";
            case ServerGlobalParams::ClusterAuthMode_x509:
                return "x509";
            default:
                return "undefined";
        }
    }

    virtual void append(OperationContext* opCtx, BSONObjBuilder& b, const std::string& name) {
        b << name << clusterAuthModeStr();
    }

    virtual Status set(const BSONElement& newValueElement) {
        try {
            return setFromString(newValueElement.String());
        } catch (const AssertionException& msg) {
            return Status(ErrorCodes::BadValue,
                          mongoutils::str::stream()
                              << "Invalid value for clusterAuthMode via setParameter command: "
                              << newValueElement
                              << ", exception: "
                              << msg.what());
        }
    }

    virtual Status setFromString(const std::string& str) {
#ifndef MONGO_CONFIG_SSL
        return Status(ErrorCodes::IllegalOperation,
                      mongoutils::str::stream() << "Unable to set clusterAuthMode, "
                                                << "SSL support is not compiled into server");
#endif
        if (str != "keyFile" && str != "sendKeyFile" && str != "sendX509" && str != "x509") {
            return Status(ErrorCodes::BadValue,
                          mongoutils::str::stream()
                              << "Invalid value for clusterAuthMode via setParameter command: "
                              << str);
        }

        int oldMode = serverGlobalParams.clusterAuthMode.load();
        int sslMode = sslGlobalParams.sslMode.load();
        if (str == "sendX509" && oldMode == ServerGlobalParams::ClusterAuthMode_sendKeyFile) {
            if (sslMode == SSLParams::SSLMode_disabled || sslMode == SSLParams::SSLMode_allowSSL) {
                return Status(ErrorCodes::BadValue,
                              mongoutils::str::stream()
                                  << "Illegal state transition for clusterAuthMode, "
                                  << "need to enable SSL for outgoing connections");
            }
            serverGlobalParams.clusterAuthMode.store(ServerGlobalParams::ClusterAuthMode_sendX509);
#ifdef MONGO_CONFIG_SSL
            setInternalUserAuthParams(
                BSON(saslCommandMechanismFieldName << "MONGODB-X509" << saslCommandUserDBFieldName
                                                   << "$external"));
#endif
        } else if (str == "x509" && oldMode == ServerGlobalParams::ClusterAuthMode_sendX509) {
            serverGlobalParams.clusterAuthMode.store(ServerGlobalParams::ClusterAuthMode_x509);
        } else {
            return Status(ErrorCodes::BadValue,
                          mongoutils::str::stream()
                              << "Illegal state transition for clusterAuthMode, change from "
                              << clusterAuthModeStr()
                              << " to "
                              << str);
        }
        return Status::OK();
    }
} clusterAuthModeSetting;

}  // namespace

}  // namespace mongo