cpipesha1.cpp

研读AxCrypt对加解密的处理方法

/*! \file
    \brief Implementation of AxStock::CPipeSHA1, calculate SHA1 of the stream

    @(#) $Id: CPipeSHA1.cpp,v 1.2 2004/06/28 19:43:40 svante Exp $

    AxPipe - Binary Stream Framework

    Copyright (C) 2003 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://axpipe.sourceforge.net

    Why is this framework released as GPL and not LGPL? See http://www.gnu.org/philosophy/why-not-lgpl.html

----
\verbatim
    E-mail                          YYYY-MM-DD              Reason
    [e-mail]              2003-12-15              Initial
\endverbatim
*/
#include "stdafx.h"
#include "CPipeSHA1.h"
#include "AxAssert.h"
#define AXLIB_ASSERT_FILE "CPipeSHA1.cpp"

namespace AxPipe {
    namespace Stock {
        /// Acquire a Crypto Context to use
        ///
        CPipeSHA1::CPipeSHA1() {
            if (!CryptAcquireContext(&m_hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT | CRYPT_MACHINE_KEYSET)) {
                SetError(AxPipe::ERROR_CODE_STOCK, _T("CPipeSHA1::CPipeSHA1() [CryptAcquireContext() failed: %s]"), my_ptr<_TCHAR>(AxLib::APerror()).get());
            }
            m_hHash = NULL;
        }

        /// Destroy the hash, if any and release the Crypto Context, if any.
        ///
        CPipeSHA1::~CPipeSHA1() {
            if (m_hHash) CryptDestroyHash(m_hHash); 
            if (m_hCryptProv) CryptReleaseContext(m_hCryptProv, 0); 
        }

        /// Add the contents of the segment to the hash, count the bytes,
        /// and send the data onwards, unchanged.
        /// \param pSeg The segment to hash.
        void
        CPipeSHA1::Out(AxPipe::CSeg *pSeg) {
            if (!CryptHashData(m_hHash, pSeg->PtrRd(), (DWORD)pSeg->Len(), 0)) {
                SetError(AxPipe::ERROR_CODE_STOCK, _T("CPipeSHA1::CPipeSHA1() [CryptHashData() failed: %s]"), my_ptr<_TCHAR>(AxLib::APerror()).get());
            }
            m_cb += pSeg->Len();
            Pump(pSeg);
        }

        ///
        /// \return The number of bytes hashed.
        unsigned __int64
        CPipeSHA1::CountBytes() {
            return m_cb;
        }

        ///
        /// \return A pointer to the resulting hash, always 160 bits/20 bytes for SHA1.
        unsigned char *
        CPipeSHA1::GetHash() {
            return (unsigned char *)m_Hash.GetLeft(160);
        }

        /// Create the hash.
        /// \return true, if we see no reason not to propagate the Open() call
        bool
        CPipeSHA1::OutOpen() {
            bool fReturn = CPipe::OutOpen();

            if (!CryptCreateHash(m_hCryptProv, CALG_SHA1, 0, 0, &m_hHash)) {
                SetError(AxPipe::ERROR_CODE_STOCK, _T("CPipeSHA1::CPipeSHA1() [CryptCreateHash() failed: %s]"), my_ptr<_TCHAR>(AxLib::APerror()).get());
            }
            m_cb = 0;
            return fReturn;
        }

        /// Finalize and get the hash data into the buffer, and destroy the hash context.
        /// \return true if the Close() call should be propagated.
        bool
        CPipeSHA1::OutClose() {
            DWORD dwHashLen = sizeof m_Hash;
            if (!CryptGetHashParam(m_hHash, HP_HASHVAL, (unsigned char *)&m_Hash, &dwHashLen, 0)) {
                SetError(AxPipe::ERROR_CODE_STOCK, _T("CPipeSHA1::OutClose() [CryptGetHashParam() failed: %s]"), my_ptr<_TCHAR>(AxLib::APerror()).get());
            }
            ASSAPI(CryptDestroyHash(m_hHash) == TRUE);
            m_hHash = NULL;
            return CPipe::OutClose();
        }   
    }
}