/****************************************************************************
* apps/include/netutils/base64.h
*
* This file is part of the NuttX RTOS:
*
* Copyright (C) 2012 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 <apps/netutils/base64.h>
#ifdef CONFIG_CODECS_BASE64
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: base64_tab
****************************************************************************/
static void base64_tab(unsigned char *tab, size_t len, bool websafe)
{
static const char *_tab =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
memset(tab, 0, len);
if (len >= 64)
{
memcpy(tab, _tab, 64);
}
if (websafe)
{
tab[62] = '-';
tab[63] = '_';
}
}
/****************************************************************************
* 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 unsigned char *_base64_encode(const unsigned char *src, size_t len,
unsigned char *dst, size_t * out_len,
bool websafe)
{
unsigned char *out;
unsigned char *pos;
const unsigned char *end;
const unsigned char *in;
size_t olen;
/*int line_len; */
unsigned char base64_table[64];
char ch = '=';
if (websafe)
{
ch = '.';
}
base64_tab(base64_table, sizeof(base64_table), websafe);
olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */
#if 0
olen += olen / 72; /* line feeds */
olen++; /* nul termination */
out = malloc(olen);
if (out == NULL)
{
return NULL;
}
#endif
end = src + len;
in = src;
if (dst)
{
pos = out = dst;
}
else
{
pos = out = malloc(olen);
if (out == NULL)
{
return NULL;
}
}
/*line_len = 0; */
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;
/* line_len += 4; */
}
if (end - in)
{
*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++ = '='; */
/* line_len += 4; */
}
#if 0
if (line_len)
{
*pos++ = '\n';
}
#endif
*pos = '\0';
if (out_len)
{
*out_len = pos - out;
}
/*out[*out_len] = '\0'; */
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(const unsigned char *src, size_t len,
unsigned char *dst, size_t * out_len,
bool websafe)
{
unsigned char dtable[256];
unsigned char *out;
unsigned char *pos;
unsigned char in[4];
unsigned char block[4];
unsigned char tmp;
size_t count;
size_t i;
unsigned char base64_table[64];
char ch = '=';
if (websafe)
{
ch = '.';
}
base64_tab(base64_table, sizeof(base64_table), websafe);
memset(dtable, 0x80, 256);
for (i = 0; i < sizeof(base64_table); i++)
{
dtable[base64_table[i]] = i;
}
dtable[(int)ch] = 0; /* dtable['='] = 0; */
count = 0;
for (i = 0; i < len; i++)
{
if (dtable[src[i]] != 0x80)
{
count++;
}
}
if (count % 4)
{
return NULL;
}
if (dst)
{
pos = out = dst;
}
else
{
pos = out = malloc(count);
if (out == NULL)
{
return NULL;
}
}
count = 0;
for (i = 0; i < len; i++)
{
tmp = dtable[src[i]];
if (tmp == 0x80)
{
continue;
}
in[count] = src[i];
block[count] = tmp;
count++;
if (count == 4)
{
*pos++ = (block[0] << 2) | (block[1] >> 4);
*pos++ = (block[1] << 4) | (block[2] >> 2);
*pos++ = (block[2] << 6) | block[3];
count = 0;
}
}
if (pos > out)
{
if (in[2] == ch) /* if (in[2] == '=') */
{
pos -= 2;
}
else if (in[3] == ch) /* else if (in[3] == '=') */
{
pos--;
}
}
*out_len = pos - out;
return out;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: base64_encode
****************************************************************************/
unsigned char *base64_encode(const unsigned char *src, size_t len,
unsigned char *dst, size_t * out_len)
{
return _base64_encode(src, len, dst, out_len, false);
}
/****************************************************************************
* Name: base64_decode
****************************************************************************/
unsigned char *base64_decode(const unsigned char *src, size_t len,
unsigned char *dst, size_t * out_len)
{
return _base64_decode(src, len, dst, out_len, false);
}
/****************************************************************************
* Name: base64w_encode
****************************************************************************/
unsigned char *base64w_encode(const unsigned char *src, size_t len,
unsigned char *dst, size_t * out_len)
{
return _base64_encode(src, len, dst, out_len, true);
}
/****************************************************************************
* Name: base64w_decode
****************************************************************************/
unsigned char *base64w_decode(const unsigned char *src, size_t len,
unsigned char *dst, size_t * out_len)
{
return _base64_decode(src, len, dst, out_len, true);
}
#endif /* CONFIG_CODECS_BASE64 */
