/****************************************************************************
* apps/netutils/codecs/base64.c
*
* This file is part of the NuttX RTOS:
*
* Copyright (C) 2012, 2018 Gregory Nutt. All rights reserved.
* Author: Darcy Gong
*
* Reference:
*
* Base64 encoding/decoding (RFC1341)
* Copyright (c) 2005, Jouni Malinen <jkmaline@cc.hut.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*
* And is re-released under the NuttX modified BSD license:
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include "netutils/base64.h"
#ifdef CONFIG_CODECS_BASE64
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: base64_tab
****************************************************************************/
static FAR const char *base64_tab(bool websafe)
{
static FAR const char *_tab =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static FAR const char *_tab_w =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789__";
return websafe ? _tab_w : _tab;
}
/****************************************************************************
* Name: _base64_encode
*
* Description:
* Base64 encode
*
* Caller is responsible for freeing the returned buffer. Returned buffer
* is NUL terminated to make it easier to use as a C string. The NUL
* terminator is not included in out_len.
*
* Input Parameters:
* src: Data to be encoded
* len: Length of the data to be encoded
* out_len: Pointer to output length variable, or NULL if not used
*
* Returned Value:
* Returns: Allocated buffer of out_len bytes of encoded data,
* or NULL on failure
*
****************************************************************************/
static FAR unsigned char *_base64_encode(FAR const unsigned char *src,
size_t len,
FAR unsigned char *dst,
FAR size_t *out_len,
bool websafe)
{
FAR unsigned char *out;
FAR unsigned char *pos;
FAR const unsigned char *end;
FAR const unsigned char *in;
FAR const char *base64_table;
char ch = '=';
size_t olen;
if (websafe)
{
ch = '.';
}
base64_table = base64_tab(websafe);
olen = (len + 2) / 3 * 4 + 1; /* 3-byte blocks to 4-byte */
end = src + len;
in = src;
if (dst)
{
pos = out = dst;
}
else
{
pos = out = malloc(olen);
if (out == NULL)
{
return NULL;
}
}
while (end - in >= 3)
{
*pos++ = base64_table[in[0] >> 2];
*pos++ = base64_table[((in[0] & 0x03) << 4) | (in[1] >> 4)];
*pos++ = base64_table[((in[1] & 0x0f) << 2) | (in[2] >> 6)];
*pos++ = base64_table[in[2] & 0x3f];
in += 3;
}
if (end - in != 0)
{
*pos++ = base64_table[in[0] >> 2];
if (end - in == 1)
{
*pos++ = base64_table[(in[0] & 0x03) << 4];
*pos++ = ch; /* *pos++ = '='; */
}
else
{
*pos++ = base64_table[((in[0] & 0x03) << 4) | (in[1] >> 4)];
*pos++ = base64_table[(in[1] & 0x0f) << 2];
}
*pos++ = ch; /* *pos++ = '='; */
}
*pos = '\0';
if (out_len)
{
*out_len = pos - out;
}
return out;
}
/****************************************************************************
* Name: _base64_decode
*
* Description:
* Base64 decode
*
* Caller is responsible for freeing the returned buffer.
*
* Input Parameters:
* src: Data to be decoded
* len: Length of the data to be decoded
* out_len: Pointer to output length variable
*
* Returned Value:
* Returns: Allocated buffer of out_len bytes of decoded data,
* or NULL on failure
*
****************************************************************************/
static unsigned char *_base64_decode(FAR const unsigned char *src,
size_t len, FAR unsigned char *dst,
FAR size_t *out_len, bool websafe)
{
FAR unsigned char *out;
FAR unsigned char *pos;
FAR unsigned char block[4];
FAR const char *base64_table;
char ch = '=';
FAR char *tmp;
size_t count;
size_t i;
if (websafe)
{
ch = '.';
}
base64_table = base64_tab(websafe);
if (dst)
{
pos = out = dst;
}
else
{
pos = out = malloc(len / 4 * 3);
if (out == NULL)
{
return NULL;
}
}
count = 0;
for (i = 0; i < len; i++)
{
tmp = strchr(base64_table, src[i]);
block[count] = tmp ? tmp - base64_table : 0;
count++;
if (count == 4)
{
*pos++ = (block[0] << 2) | (block[1] >> 4);
if (src[i - 1] == ch)
{
break;
}
*pos++ = (block[1] << 4) | (block[2] >> 2);
if (src[i] == ch)
{
break;
}
*pos++ = (block[2] << 6) | block[3];
count = 0;
}
}
*out_len = pos - out;
return out;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: base64_encode_length
****************************************************************************/
size_t base64_encode_length(size_t len)
{
return (len + 2) / 3 * 4;
}
/****************************************************************************
* Name: base64_encode
****************************************************************************/
FAR void *base64_encode(FAR const void *src, size_t len, FAR void *dst,
FAR size_t *out_len)
{
return _base64_encode(src, len, dst, out_len, false);
}
/****************************************************************************
* Name: base64_decode_length
****************************************************************************/
size_t base64_decode_length(size_t len)
{
return len * 3 / 4;
}
/****************************************************************************
* Name: base64_decode
****************************************************************************/
FAR void *base64_decode(FAR const void *src, size_t len, FAR void *dst,
FAR size_t *out_len)
{
return _base64_decode(src, len, dst, out_len, false);
}
/****************************************************************************
* Name: base64w_encode
****************************************************************************/
FAR void *base64w_encode(FAR const void *src, size_t len, FAR void *dst,
FAR size_t *out_len)
{
return _base64_encode(src, len, dst, out_len, true);
}
/****************************************************************************
* Name: base64w_decode
****************************************************************************/
FAR void *base64w_decode(FAR const void *src, size_t len, FAR void *dst,
FAR size_t *out_len)
{
return _base64_decode(src, len, dst, out_len, true);
}
#endif /* CONFIG_CODECS_BASE64 */