basemdec.h

研读AxCrypt对加解密的处理方法

#ifndef AXSIGLIB_BASEMDEC_H
#define AXSIGLIB_BASEMDEC_H
/*! \file
    \brief AxSigLib - Short Elliptic Curve Digital Signature Algorithm et. al.

    @(#) $Id$

    Decode BaseM strings. These are based on the encoding vectors such as (for Base34):

    static const byte s_vecUpper[] = "ABCDEFGHIJKLMNPQRSTUVWXYZ123456789";
    static const byte s_vecLower[] = "abcdefghijklmnpqrstuvwxyz123456789";

    Copyright (C) 2005 Svante Seleborg/Axon Data, All rights reserved.

    This program is free software; you can redistribute it and/or modify it under the terms
    of the GNU General Public License as published by the Free Software Foundation;
    either version 2 of the License, or (at your option) any later version.

    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 General Public License for more details.

    You should have received a copy of the GNU General Public License along with this program;
    if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
    Boston, MA 02111-1307 USA

    The author may be reached at mailto:[e-mail] and http://axcrypt.sourceforge.net
----
*/

#include "BaseM.h"

//! base m decoder, where m is any number <= number of printable characters.
class BaseM_Decoder : public BaseN_Decoder {
public:
    BaseM_Decoder(const int *lookup, int anybase, int bits, BufferedTransformation *attachment=NULL) {
        Detach(attachment);
        IsolatedInitialize(MakeParameters(Name::DecodingLookupArray(), lookup)
                                         (Name::AnyBase(), anybase)
                                         (Name::BitPrecision(), bits));
    }

    void IsolatedInitialize(const NameValuePairs &parameters);
    unsigned int Put2(const byte *begin, unsigned int length, int messageEnd, bool blocking);

    static void InitializeDecodingLookupArray(int *lookup, const byte *alphabet, unsigned int base, bool caseInsensitive);

private:
    const int *m_lookup;
    int m_padding, m_base, m_bits;
    SecByteBlock m_buffer;
};

#endif