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#pragma once

#include "sshexception_p.h"

#include <QtEndian>
#include <QByteArray>
#include <QList>

namespace Botan { class BigInt; }

namespace QSsh {
namespace Internal {

enum SshPacketType {
    SSH_MSG_DISCONNECT = 1,
    SSH_MSG_IGNORE = 2,
    SSH_MSG_UNIMPLEMENTED = 3,
    SSH_MSG_DEBUG = 4,
    SSH_MSG_SERVICE_REQUEST = 5,
    SSH_MSG_SERVICE_ACCEPT = 6,

    SSH_MSG_KEXINIT = 20,
    SSH_MSG_NEWKEYS = 21,
    SSH_MSG_KEXDH_INIT = 30,
    SSH_MSG_KEX_ECDH_INIT = 30,
    SSH_MSG_KEXDH_REPLY = 31,
    SSH_MSG_KEX_ECDH_REPLY = 31,

    SSH_MSG_USERAUTH_REQUEST = 50,
    SSH_MSG_USERAUTH_FAILURE = 51,
    SSH_MSG_USERAUTH_SUCCESS = 52,
    SSH_MSG_USERAUTH_BANNER = 53,
    SSH_MSG_USERAUTH_PK_OK = 60,
    SSH_MSG_USERAUTH_PASSWD_CHANGEREQ = 60,
    SSH_MSG_USERAUTH_INFO_REQUEST = 60,
    SSH_MSG_USERAUTH_INFO_RESPONSE = 61,

    SSH_MSG_GLOBAL_REQUEST = 80,
    SSH_MSG_REQUEST_SUCCESS = 81,
    SSH_MSG_REQUEST_FAILURE = 82,

    // TODO: We currently take no precautions against sending these messages
    //       during a key re-exchange, which is not allowed.
    SSH_MSG_CHANNEL_OPEN = 90,
    SSH_MSG_CHANNEL_OPEN_CONFIRMATION = 91,
    SSH_MSG_CHANNEL_OPEN_FAILURE = 92,
    SSH_MSG_CHANNEL_WINDOW_ADJUST = 93,
    SSH_MSG_CHANNEL_DATA = 94,
    SSH_MSG_CHANNEL_EXTENDED_DATA = 95,
    SSH_MSG_CHANNEL_EOF = 96,
    SSH_MSG_CHANNEL_CLOSE = 97,
    SSH_MSG_CHANNEL_REQUEST = 98,
    SSH_MSG_CHANNEL_SUCCESS = 99,
    SSH_MSG_CHANNEL_FAILURE = 100,

    // Not completely safe, since the server may actually understand this
    // message type as an extension. Switch to a different value in that case
    // (between 128 and 191).
    SSH_MSG_INVALID = 128
};

enum SshOpenFailureType {
    SSH_OPEN_ADMINISTRATIVELY_PROHIBITED = 1,
    SSH_OPEN_CONNECT_FAILED = 2,
    SSH_OPEN_UNKNOWN_CHANNEL_TYPE = 3,
    SSH_OPEN_RESOURCE_SHORTAGE = 4
};

enum SshExtendedDataType { SSH_EXTENDED_DATA_STDERR = 1 };

class SshAbstractCryptoFacility;

class AbstractSshPacket
{
public:
    virtual ~AbstractSshPacket();

    void clear();
    bool isComplete() const;
    SshPacketType type() const;

    static QByteArray encodeString(const QByteArray &string);
    static QByteArray encodeMpInt(const Botan::BigInt &number);
    template<typename T> static QByteArray encodeInt(T value)
    {
        const T valMsb = qToBigEndian(value);
        return QByteArray(reinterpret_cast<const char *>(&valMsb), sizeof valMsb);
    }

    static void setLengthField(QByteArray &data);

    void printRawBytes() const; // For Debugging.

    const QByteArray &rawData() const { return m_data; }

    QByteArray payLoad() const;

protected:
    AbstractSshPacket();

    virtual quint32 cipherBlockSize() const = 0;
    virtual quint32 macLength() const = 0;
    virtual void calculateLength() const;

    quint32 length() const;
    int paddingLength() const;
    quint32 minPacketSize() const;
    quint32 currentDataSize() const { return m_data.size(); }
    QByteArray generateMac(const SshAbstractCryptoFacility &crypt,
        quint32 seqNr) const;

    static const quint32 PaddingLengthOffset;
    static const quint32 PayloadOffset;
    static const quint32 TypeOffset;
    static const quint32 MinPaddingLength;

    mutable QByteArray m_data;
    mutable quint32 m_length;
};

} // namespace Internal
} // namespace QSsh