Re: [Boost-users] base64_from_binary Q

From: Vinzenz Feenstra (evilissimo_at_[hidden])
Date: 2008-08-27 02:25:44

Hi,

Well I ran into this issue too. This is the way how I've solved this:

     template<typename InputContainerType>
     inline String base64_encode(InputContainerType const & cont)
     {
       using namespace boost::archive::iterators;
       typedef base64_from_binary<
         transform_width<
         typename InputContainerType::const_pointer, 6, 8, boost::uint8_t
         >
       > base64_t;
       return String(base64_t(&cont[0]), base64_t(&cont[0] + cont.size()));
     }

     template<typename Container, typename CharT>
     inline Container base64_decode(std::basic_string<CharT> str)
     {
       str.append(str.size() % 4, CharT('='));
       typedef boost::archive::iterators::transform_width<
         boost::archive::iterators::binary_from_base64<CharT *>, 8, 6, 
boost::uint8_t
       > binary_t;

       typename std::basic_string<CharT>::size_type pos = 
str.find_last_not_of(CharT('='));
       // calculate how many characters we need to process
       pos = (pos == str.size() -1 ? str.size() : pos );
       return Container(binary_t(&str[0]), binary_t(&str[0] + pos));
     }

So far it seemed to work for me, but still might have a bug.

Regards,
Vinzenz

Terdale, Shantibhushan schrieb:
> I am using this sample to prove myself that base64_from_binary and 
> binary_from_base64 can be used in my app. But I am having little problem 
> and not able to understand whats missing
>  
> Here is the sample
>  
> 
> #include "boost/archive/iterators/base64_from_binary.hpp"
> 
> #include "boost/archive/iterators/binary_from_base64.hpp"
> 
> #include "boost/archive/iterators/transform_width.hpp"
> 
> #include <string>
> 
> #include <iostream>
> 
> using namespace std;
> 
> using namespace boost::archive::iterators;
> 
> typedef
> 
> base64_from_binary<
> 
> transform_width<std::string::iterator, 6, sizeof(char) * 8>
> 
>>  base64_t;
> 
> typedef
> 
> transform_width<
> 
> binary_from_base64<std::string::iterator>, sizeof(char) * 8, 6
> 
>>  binary_t;
> 
> int main()
> 
> {
> 
> string str = "Hello, world!";
> 
> cout << str << endl;
> 
> string enc(base64_t(str.begin()), base64_t(str.end()));    *// Problem 
> here. It works when I specify "str.end()-1" instead of "str.end()" but I 
> loose last character after decoding.*
> 
> cout << enc << endl;
> 
> string dec(binary_t(enc.begin()), binary_t(enc.end()));
> 
> cout << dec << endl;
> 
> return 0;
> 
> }
> 
> Will appreciate any help.  I tried std::copy as well and have same problem.
> 
>  
> 
>  
> 
>  
> 
> 
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