Question

I’m trying to quickly encode a simple ASCII string to base64 (Basic HTTP Authentication using boost::asio) and not paste in any new code code or use any libraries beyond boost.

Simple signature would look like:
string Base64Encode(const string& text);

Again I realize the algorithm is easy and there are many libraries/examples doing this but I’m looking for a clean boost example. I found boost serialization but no clear examples there or from Google.
http://www.boost.org/doc/libs/1_46_1/libs/serialization/doc/dataflow.html

Is this possible without adding the actual base64 algorithm explicitly to my code?

Answer 1

I improved the example in the link you provided a little:

#include <boost/archive/iterators/base64_from_binary.hpp>
#include <boost/archive/iterators/insert_linebreaks.hpp>
#include <boost/archive/iterators/transform_width.hpp>
#include <boost/archive/iterators/ostream_iterator.hpp>
#include <sstream>
#include <string>
#include <iostream>


int main()
{
    using namespace boost::archive::iterators;

    std::string test = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Fusce ornare ullamcorper ipsum ac gravida.";

    std::stringstream os;
    typedef 
        insert_linebreaks<         // insert line breaks every 72 characters
            base64_from_binary<    // convert binary values to base64 characters
                transform_width<   // retrieve 6 bit integers from a sequence of 8 bit bytes
                    const char *,
                    6,
                    8
                >
            > 
            ,72
        > 
        base64_text; // compose all the above operations in to a new iterator

    std::copy(
        base64_text(test.c_str()),
        base64_text(test.c_str() + test.size()),
        ostream_iterator<char>(os)
    );

    std::cout << os.str();
}

This prints the string encoded base64 nicely formated with a line break every 72 characters onto the console, ready to be put into an email. If you don’t like the linebreaks, just stay with this:

    typedef 
        base64_from_binary<
           transform_width<
                const char *,
                6,
                8
            >
        > 
        base64_text;