Function tss_encode_base64

src/tripwire/mailmessage.cpp:759–810

size_t tss_encode_base64(const byte_t* pchSource, size_t nchSource, byte_t* pchBuffer, size_t nchBuffer)
{
    const size_t _ERROR = std::string::npos; // -1;


    //--Assert Preconditions

    if (pchSource == 0 || nchSource == 0)
        return _ERROR;


    //--If pchBuffer == 0, User is requesting Size

    size_t nchBuf = tss_encode_base64_size(nchSource);

    if (pchBuffer == 0) // Requesting Size
        return nchBuf;

    if (nchBuf > nchBuffer) // DOH!!
        return _ERROR;


    //--Get three characters at a time and encode them (watching linelen)

    byte_t* pchBuf = (pchBuffer + 0);
    const byte_t* pchSrc = (pchSource + 0);


    const size_t _max_linelen = (_MAX_RFC822_LINE_LEN - _EOL_LEN);
    size_t nLineLen = 0;

    for (; nchSource;)
    {
        // Like iconv: Increment pointers and decrement sizes
        tss_encode_digit_base64(pchSrc, nchSource, pchBuf, nchBuf);

        nLineLen += 4;

        if (nchSource == 0 || nLineLen > _max_linelen)
        {
            nLineLen = 0; // RESET:

            const byte_t* pchEol = &_aszEoL[0];
            while (*pchEol)
                *pchBuf++ = *pchEol++;
        }
    }

    *pchBuf = 0x00; // CAUTION: Null Terminate!!!

    return (pchBuf - pchBuffer);
}
} // namespace