base64 encode/decode for std::istreambuf_iterator/std::ostreambuf_iterator

[nen777w@…]

MSVS 2008 The code:

#include "boost/archive/iterators/base64_from_binary.hpp"
#include "boost/archive/iterators/binary_from_base64.hpp"
#include "boost/archive/iterators/transform_width.hpp"

//typedefs
typedef  std::istreambuf_iterator<char>    my_istream_iterator;
typedef  std::ostreambuf_iterator<char>    my_ostream_iterator;

typedef boost::archive::iterators::base64_from_binary<
          boost::archive::iterators::transform_width< my_istream_iterator, 6, 8>
> bin_to_base64;

typedef boost::archive::iterators::transform_width<
    boost::archive::iterators::binary_from_base64< my_istream_iterator >, 8, 6
> base64_to_bin;

void test()
{
   {
        //INPUT FILE!!!
    std::ifstream ifs("test.zip", std::ios_base::in|std::ios_base::binary);
    std::ofstream ofs("test.arc", std::ios_base::out|std::ios_base::binary);

    std::copy(
        bin_to_base64( my_istream_iterator(ifs >> std::noskipws) ),
        bin_to_base64( my_istream_iterator() ),
        my_ostream_iterator(ofs)
    );
  }

  {
    std::ifstream ifs("test.arc", std::ios_base::in|std::ios_base::binary);
    std::ofstream ofs("test.rez", std::ios_base::out|std::ios_base::binary);

    std::copy(
        base64_to_bin( my_istream_iterator(ifs >> std::noskipws) ),
        base64_to_bin( my_istream_iterator() ),
        my_ostream_iterator(ofs)
    );
  }
}

Result: 1) If the INPUT FILE will be any of ZIP-file format. The result was:

a) _DEBUG_ERROR("istreambuf_iterator is not dereferencable"); it can be disabled or ignored b) The encoded file "test.rez" will have one superfluous byte than INPUT FILE

2) If the INPUT FILE will any other file (binary or text) all will be OK.

[anonymous]

The problem description and solution I describe in this topic on RSDN.RU ​http://rsdn.ru/forum/cpp.applied/4315109.aspx

[nen777w@…]

If it may help. The workaround code and example how to use you can find here: ​http://rsdn.ru/forum/cpp.applied/4317966.1.aspx

[Ferdinand Prantl <prantlf@…>]

The workaround presented above uses a stream wrapper to fix the problem. Another solution could be fixing the transforming iterator.

Could this be connected to the transform_width implementation, which works only if the input size is aligned to the unit quantum? If it is not, you'd have to apply/recognize padding correctly: ticket:5629#comment:10.