base64.cpp

/**
 * base64.cpp
 *
 * Created on: 09.12.2015
 *
 * Copyright (c) 2015 Markus Sattler. All rights reserved.
 * This file is part of the ESP8266 core for Arduino.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "Arduino.h"
extern "C" {
#include "libb64/cencode.h"
}
#include "base64.h"

/**
 * convert input data to base64
 * @param data const uint8_t *
 * @param length size_t
 * @return String
 */
String base64::encode(const uint8_t * data, size_t length, bool doNewLines)
{
    String base64;

    // base64 needs more size then the source data, use cencode.h macros
    size_t size = ((doNewLines ? base64_encode_expected_len( length )
                    : base64_encode_expected_len_nonewlines( length )) + 1);

    if (base64.reserve(size))
    {

        base64_encodestate _state;
        if (doNewLines)
        {
            base64_init_encodestate(&_state);
        }
        else
        {
            base64_init_encodestate_nonewlines(&_state);
        }

        constexpr size_t BUFSIZE = 48;
        char buf[BUFSIZE + 1 /* newline */ + 1 /* NUL */];
        for (size_t len = 0; len < length; len += BUFSIZE * 3 / 4)
        {
            size_t blocklen = base64_encode_block((const char*) data + len,
                                                  std::min( BUFSIZE * 3 / 4, length - len ), buf, &_state);
            buf[blocklen] = '\0';
            base64 += buf;
        }
        if (base64_encode_blockend(buf, &_state))
            base64 += buf;
    }
    else
    {
        base64 = F("-FAIL-");
    }

    return base64;
}