/**
 * \file base64.h
 *
 * \brief RFC 1521 base64 encoding/decoding
 *
 *  Copyright (C) 2006-2013, ARM Limited, All Rights Reserved
 *
 *  This file is part of mbed TLS (https://tls.mbed.org)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef POLARSSL_BASE64_H
#define POLARSSL_BASE64_H

#include <stddef.h>
#include <limits.h>

#define POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL               -0x002A  /**< Output buffer too small. */
#define POLARSSL_ERR_BASE64_INVALID_CHARACTER              -0x002C  /**< Invalid character in input. */

#ifdef __cplusplus
extern "C" {
#endif

/**
 * \brief          Encode a buffer into base64 format
 *
 * \param dst      destination buffer
 * \param dlen     size of the buffer
 * \param src      source buffer
 * \param slen     amount of data to be encoded
 *
 * \return         0 if successful, or POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL.
 *                 *dlen is always updated to reflect the amount
 *                 of data that has (or would have) been written.
 *                 If that length cannot be represented, then no data is
 *                 written to the buffer and *dlen is set to SIZE_T_MAX.
 *
 * \note           Call this function with *dlen = 0 to obtain the
 *                 required buffer size in *dlen
 */
int base64_encode( unsigned char *dst, size_t *dlen,
                   const unsigned char *src, size_t slen );

/**
 * \brief          Decode a base64-formatted buffer
 *
 * \param dst      destination buffer (can be NULL for checking size)
 * \param dlen     size of the buffer
 * \param src      source buffer
 * \param slen     amount of data to be decoded
 *
 * \return         0 if successful, POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL, or
 *                 POLARSSL_ERR_BASE64_INVALID_CHARACTER if the input data is
 *                 not correct. *dlen is always updated to reflect the amount
 *                 of data that has (or would have) been written.
 *
 * \note           Call this function with *dst = NULL or *dlen = 0 to obtain
 *                 the required buffer size in *dlen
 */
int base64_decode( unsigned char *dst, size_t *dlen,
                   const unsigned char *src, size_t slen );

/**
 * \brief          Checkup routine
 *
 * \return         0 if successful, or 1 if the test failed
 */
int base64_self_test( int verbose );

#ifdef __cplusplus
}
#endif

#endif /* base64.h */