/*    Copyright 2012 10gen 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/client/sasl_client_authenticate.h"

#include <string>

#include "mongo/base/string_data.h"
#include "mongo/bson/util/bson_extract.h"
#include "mongo/util/base64.h"
#include "mongo/util/mongoutils/str.h"

namespace mongo {

using namespace mongoutils;

void (*saslClientAuthenticate)(auth::RunCommandHook runCommand,
                               StringData hostname,
                               const BSONObj& saslParameters,
                               auth::AuthCompletionHandler handler) = nullptr;

const char* const saslStartCommandName = "saslStart";
const char* const saslContinueCommandName = "saslContinue";
const char* const saslCommandAutoAuthorizeFieldName = "autoAuthorize";
const char* const saslCommandCodeFieldName = "code";
const char* const saslCommandConversationIdFieldName = "conversationId";
const char* const saslCommandDoneFieldName = "done";
const char* const saslCommandErrmsgFieldName = "errmsg";
const char* const saslCommandMechanismFieldName = "mechanism";
const char* const saslCommandMechanismListFieldName = "supportedMechanisms";
const char* const saslCommandPasswordFieldName = "pwd";
const char* const saslCommandPayloadFieldName = "payload";
const char* const saslCommandUserDBFieldName = "db";
const char* const saslCommandUserFieldName = "user";
const char* const saslCommandServiceHostnameFieldName = "serviceHostname";
const char* const saslCommandServiceNameFieldName = "serviceName";
const char* const saslCommandDigestPasswordFieldName = "digestPassword";
const char* const saslDefaultDBName = "$external";
const char* const saslDefaultServiceName = "mongodb";

Status saslExtractPayload(const BSONObj& cmdObj, std::string* payload, BSONType* type) {
    BSONElement payloadElement;
    Status status = bsonExtractField(cmdObj, saslCommandPayloadFieldName, &payloadElement);
    if (!status.isOK())
        return status;

    *type = payloadElement.type();
    if (payloadElement.type() == BinData) {
        const char* payloadData;
        int payloadLen;
        payloadData = payloadElement.binData(payloadLen);
        if (payloadLen < 0)
            return Status(ErrorCodes::InvalidLength, "Negative payload length");
        *payload = std::string(payloadData, payloadData + payloadLen);
    } else if (payloadElement.type() == String) {
        try {
            *payload = base64::decode(payloadElement.str());
        } catch (UserException& e) {
            return Status(ErrorCodes::FailedToParse, e.what());
        }
    } else {
        return Status(ErrorCodes::TypeMismatch,
                      (str::stream() << "Wrong type for field; expected BinData or String for "
                                     << payloadElement));
    }

    return Status::OK();
}
}  // namespace mongo