// Copyright (C) 2022 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

// Qt-Security score:significant reason:default

#ifndef QHTTPHEADERPARSER_H

#define QHTTPHEADERPARSER_H

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists for the convenience

// of the Network Access API.  This header file may change from

// version to version without notice, or even be removed.

//

// We mean it.

//

#include <QtNetwork/private/qtnetworkglobal_p.h>

#include <QtNetwork/qhttpheaders.h>

#include <QByteArray>

#include <QList>

#include <QString>

QT_BEGIN_NAMESPACE

namespace HeaderConstants {

// We previously used 8K, which is common on server side, but it turned out to

// not be enough for various uses. Historically Firefox used 10K as the limit of

// a single field, but some Location headers and Authorization challenges can

// get even longer. Other browsers, such as Chrome, instead have a limit on the

// total size of all the headers (as well as extra limits on some of the

// individual fields). We'll use 100K as our default limit, which would be a ridiculously large

// header, with the possibility to override it where we need to.

static constexpr qsizetype DEFAULT_MAX_HEADER_FIELD_SIZE = 100 * 1024;

// Taken from http://httpd.apache.org/docs/2.2/mod/core.html#limitrequestfields

static constexpr qsizetype DEFAULT_MAX_HEADER_FIELDS = 100;

// Chromium has a limit on the total size of the header set to 256KB,

// which is a reasonable default for QNetworkAccessManager.

// https://stackoverflow.com/a/3436155

static constexpr qsizetype DEFAULT_MAX_TOTAL_HEADER_SIZE = 256 * 1024;

// There is no strict upper limit on the phrase, but in practice it is

// rarely longer than 28. 1024 is quite generous, allows custom messages

static constexpr qsizetype MAX_REASON_PHRASE_SIZE = 1024;

}

class Q_NETWORK_EXPORT QHttpHeaderParser

{

public:

    QHttpHeaderParser();

    void clear();

    bool parseHeaders(QByteArrayView headers);

    bool parseStatus(QByteArrayView status);

    const QHttpHeaders& headers() const &;

    QHttpHeaders headers() &&;

    void setStatusCode(int code);

    int getStatusCode() const;

    int getMajorVersion() const;

    void setMajorVersion(int version);

    int getMinorVersion() const;

    void setMinorVersion(int version);

    QString getReasonPhrase() const;

    void setReasonPhrase(const QString &reason);

    QByteArray firstHeaderField(QByteArrayView name,

                                const QByteArray &defaultValue = QByteArray()) const;

    QByteArray combinedHeaderValue(QByteArrayView name,

                                   const QByteArray &defaultValue = QByteArray()) const;

    QList<QByteArray> headerFieldValues(QByteArrayView name) const;

    void setHeaderField(const QByteArray &name, const QByteArray &data);

    void prependHeaderField(const QByteArray &name, const QByteArray &data);

    void appendHeaderField(const QByteArray &name, const QByteArray &data);

    void removeHeaderField(QByteArrayView name);

    void clearHeaders();

    void setMaxHeaderFieldSize(qsizetype size) {

        Q_ASSERT(size > 0);

        maxFieldSize = size;

    }

    qsizetype maxHeaderFieldSize() const { return maxFieldSize; }

    void setMaxTotalHeaderSize(qsizetype size) {

        Q_ASSERT(size > 0);

        maxTotalSize = size;

    }

    qsizetype maxTotalHeaderSize() const { return maxTotalSize; }

    qsizetype maxRawHeaderSize() const {

        constexpr qsizetype TrailingLineEndings = 4;

        qsizetype result;

        if (qAddOverflow(maxTotalSize, TrailingLineEndings, &result))

            return (std::numeric_limits<qsizetype>::max)();

        return result;

    }

    void setMaxHeaderFields(qsizetype size) {

        Q_ASSERT(size > 0);

        maxFieldCount = size;

    }

    qsizetype maxHeaderFields() const { return maxFieldCount; }

private:

    QHttpHeaders fields;

    QString reasonPhrase;

    int statusCode;

    int majorVersion;

    int minorVersion;

    qsizetype maxFieldSize = HeaderConstants::DEFAULT_MAX_HEADER_FIELD_SIZE;

    qsizetype maxTotalSize = HeaderConstants::DEFAULT_MAX_TOTAL_HEADER_SIZE;

    qsizetype maxFieldCount = HeaderConstants::DEFAULT_MAX_HEADER_FIELDS;

};

QT_END_NAMESPACE

#endif // QHTTPHEADERPARSER_H