void CSHA1::Update(const UINT_8* pbData, UINT_32 uLen)
{
    UINT_32 j = ((m_count[0] >> 3) & 0x3F);

    if((m_count[0] += (uLen << 3)) < (uLen << 3))
        ++m_count[1]; // Overflow

    m_count[1] += (uLen >> 29);

    UINT_32 i;
    if((j + uLen) > 63)
    {
        i = 64 - j;
        memcpy(&m_buffer[j], pbData, i);
        Transform(m_state, m_buffer);

        for( ; (i + 63) < uLen; i += 64)
            Transform(m_state, &pbData[i]);

        j = 0;
    }
    else i = 0;

    if((uLen - i) != 0)
        memcpy(&m_buffer[j], &pbData[i], uLen - i);
}

#ifdef SHA1_UTILITY_FUNCTIONS
// Hash in file contents
bool CSHA1::HashFile(const TCHAR* tszFileName)
{
    if(tszFileName == NULL) return false;

    FILE* fpIn = _tfopen(tszFileName, _T("rb"));
    if(fpIn == NULL) return false;

    _fseeki64(fpIn, 0, SEEK_END);
    const INT_64 lFileSize = _ftelli64(fpIn);
    _fseeki64(fpIn, 0, SEEK_SET);

    const INT_64 lMaxBuf = SHA1_MAX_FILE_BUFFER;
    UINT_8 vData[SHA1_MAX_FILE_BUFFER];
    INT_64 lRemaining = lFileSize;

    while(lRemaining > 0)
    {
        const size_t uMaxRead = static_cast<size_t>((lRemaining > lMaxBuf) ?
            lMaxBuf : lRemaining);

        const size_t uRead = fread(vData, 1, uMaxRead, fpIn);
        if(uRead == 0)
        {
            fclose(fpIn);
            return false;
        }

        Update(vData, static_cast<UINT_32>(uRead));

        lRemaining -= static_cast<INT_64>(uRead);
    }

    fclose(fpIn);
    return (lRemaining == 0);
}
#endif

void CSHA1::Final()
{
    UINT_32 i;

    UINT_8 finalcount[8];
    for(i = 0; i < 8; ++i)
        finalcount[i] = (UINT_8)((m_count[((i >= 4) ? 0 : 1)]
            >> ((3 - (i & 3)) * 8) ) & 255); // Endian independent

    Update((UINT_8*)"\200", 1);

    while ((m_count[0] & 504) != 448)
        Update((UINT_8*)"\0", 1);

    Update(finalcount, 8); // Cause a SHA1Transform()

    for(i = 0; i < 20; ++i)
        m_digest[i] = (UINT_8)((m_state[i >> 2] >> ((3 - (i & 3)) * 8)) & 0xFF);

    // Wipe variables for security reasons
#ifdef SHA1_WIPE_VARIABLES
    memset(m_buffer, 0, 64);
    memset(m_state, 0, 20);
    memset(m_count, 0, 8);
    memset(finalcount, 0, 8);
    Transform(m_state, m_buffer);
#endif
}