Encode Base64 with OpenSSL 1.0.2h

EncodeBase64.cpp

#include <cstdint>
#include <string>
#include <vector>

#include <openssl/evp.h>
#include <openssl/buffer.h>


namespace {

bool EncodeBase64(std::string & out, const std::vector<uint8_t> & in)
{
    if (INT_MAX < in.size())
    {
        return false;
    }
    
    auto bio = BIO_new(BIO_s_mem());
    if (!bio)
    {
        return false;
    }
    
    auto b64 = BIO_new(BIO_f_base64());
    if (!b64)
    {
        BIO_free(bio);
        return false;
    }
    
    BIO_push(b64, bio);
    
    BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
    
    auto size = static_cast<int>(in.size());
    auto writeBytes =
        BIO_write(b64, static_cast<const void *>(in.data()), size);
    if (0 >= writeBytes)
    {
        BIO_free_all(b64);
        
        return false;
    }
    
    if (BIO_flush(b64) != 1)
    {
        BIO_free_all(b64);
        
        return false;
    }
    
    BUF_MEM * bptr = nullptr;
    if (BIO_get_mem_ptr(b64, &bptr) != 1)
    {
        BIO_free_all(b64);
        
        return false;
    }
    
    out.assign(bptr->data, bptr->length);

    BIO_free_all(b64);

    return true;
}

}