base64 decode c++ fail end of line byte

Question

I would like to decode a string of a large file in c++.

The size of the chain is: 1827500 characters and the file is: 1370626 bytes

My problem is that the decoding function does not work. The decoded file is different from the original file.

Below are two ways I've tried

First :

char  *base64_decode(const std::string &input, long *size)
{
    BIO *p_bio_mem = nullptr;
    BIO *p_bio_b64 = nullptr;
    char *retrnvalue;

    p_bio_b64 = BIO_new(BIO_f_base64());
    if (!p_bio_b64) { throw std::runtime_error("BIO_new failed"); }
    BIO_set_flags(p_bio_b64, BIO_FLAGS_BASE64_NO_NL); //Don't require trailing newlines

    p_bio_mem = BIO_new_mem_buf((void*)input.c_str(), input.length());
    if (!p_bio_mem) { throw std::runtime_error("BIO_new failed"); }
    BIO_push(p_bio_b64, p_bio_mem);

    // read result from chain
    // read sequence (reverse to write): buf <<-- p_bio_b64 <<-- p_bio_mem
    std::vector<char> buf((input.size() * 3 / 4) + 1);
    std::string result;
    for (;;)
    {
        auto nread = BIO_read(p_bio_b64, buf.data(), buf.size());
        if (nread < 0) { return NULL; //fail}
        if (nread == 0) { break; } // eof
        result.append(buf.data(), nread);
    }

    BIO_free_all(p_bio_b64);
    *size = buf.size();
    retrnvalue = new char[*size];
    memcpy(retrnvalue, buf.data(), *size);

    return retrnvalue;
}

Second:

Code from here : How do I base64 encode (decode) in C?

Some end of lines are different:

But not the entire file:

Can you tell me why? and / or tell me another way to encode a file for easy transfert ?

I have this in input : drive.google.com/file/d/0B1i4Ez8N86wFblJnaFF6YVNVTWs/view

And i want this in output : drive.google.com/file/d/0B1i4Ez8N86wFdl9OUE5UMFB3R28/view

(sorry i can't put more than 2 links)

PS: When i decode with "certutil -decode" in batch, it works without problems.

SOLVED : Problem solved, the problem was fwrite . Fix with ofstream write function

Answer 1

SOLVED : Problem solved, the problem was fwrite . Fix with ofstream write function