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/*-
* Copyright (c) 2003 - 2016 Rozhuk Ivan <rozhuk.im@gmail.com>
* Copyright (c) 2018 sss <sss at dark-alexandr dot net>
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
*/
#pragma once
static const uint8_t *base64_url_tbl_coding = (const uint8_t
*)"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
static const uint8_t base64_url_tbl_decoding[256] = {64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
62, 64, 64, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64,
64, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 63, 64, 26, 27, 28, 29, 30, 31, 32,
33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64};
static inline int
base64_url_encode(uint8_t *src, size_t src_size, uint8_t *dst, size_t dst_size,
size_t *enc_size)
{
size_t tm, src_m3_size;
register uint8_t *wpos, *rpos, *src_m3_max;
if (NULL == src || 0 == src_size)
return (EINVAL);
/* dst buf size calculation. */
tm = (src_size / 3);
src_m3_size = (tm * 3);
if (src_m3_size != src_size)
{ /* is multiple of 3? */
tm++;
}
tm *= 4;
if (NULL != enc_size)
{
(*enc_size) = tm;
}
if (dst_size < tm) /* Is dst buf too small? */
return (ENOBUFS);
if (NULL == dst)
return (EINVAL);
wpos = dst;
rpos = src;
/* Main loop: encode 3 -> 4 */
for (src_m3_max = (src + src_m3_size); rpos < src_m3_max; rpos += 3)
{
(*wpos++) = base64_url_tbl_coding[rpos[0] >> 2]; /* c1 */
(*wpos++)
= base64_url_tbl_coding[((rpos[0] << 4) & 0x30)
| ((rpos[1] >> 4) & 0x0f)]; /* c2 */
(*wpos++)
= base64_url_tbl_coding[((rpos[1] << 2) & 0x3c)
| ((rpos[2] >> 6) & 0x03)]; /* c3 */
(*wpos++) = base64_url_tbl_coding[rpos[2] & 0x3f]; /* c4 */
}
/* Tail special encoding. */
if (src_size != src_m3_size)
{ /* If src_size was not a multiple of 3: 1-2 bytes tail special coding.
*/
(*wpos++) = base64_url_tbl_coding[rpos[0] >> 2]; /* c1 */
if (1 == (src_size - src_m3_size))
{ /* 1 byte tail. */
(*wpos++) = base64_url_tbl_coding[(
(rpos[0] << 4) & 0x30)]; /* c2 */
(*wpos++) = '='; /* c3: tail padding. */
}
else
{ /* 2 bytes tail. */
(*wpos++)
= base64_url_tbl_coding[((rpos[0] << 4) & 0x30)
| ((rpos[1] >> 4)
& 0x0f)]; /* c2 */
(*wpos++) = base64_url_tbl_coding[(
(rpos[1] << 2) & 0x3c)]; /* c3 */
}
(*wpos++) = '='; /* c4: tail padding. */
}
(*wpos) = 0;
#if 0
if ((wpos - dst) != tm) { /* Must be euqual! */
(*enc_size) = (wpos - dst);
}
#endif
return (0);
}
static inline int
base64_url_decode(uint8_t *src, size_t src_size, uint8_t *dst, size_t dst_size,
size_t *dcd_size)
{
size_t tm, src_m4_size;
register uint8_t *wpos, *rpos, *src_m4_max;
if (NULL == src || 2 > src_size)
return (EINVAL);
/* Remove tail padding. */
for (; 0 < src_size; src_size--)
{
if ('=' != src[(src_size - 1)])
break;
}
if (2 > src_size) /* Check again: at least 2 byte needed for decoder. */
return (EINVAL);
/* dst buf size calculation. */
tm = (src_size / 4);
src_m4_size = (tm * 4);
if (src_m4_size != src_size)
{ /* is multiple of 4? */
tm++;
}
tm *= 3;
if (dst_size < tm)
{ /* Is dst buf too small? */
if (NULL != dcd_size)
{
(*dcd_size) = tm;
}
return (ENOBUFS);
}
if (NULL == dst)
return (EINVAL);
wpos = dst;
rpos = src;
/* Main loop: decode 4 -> 3 */
for (src_m4_max = (src + src_m4_size); rpos < src_m4_max; rpos += 4)
{
(*wpos++) = (base64_url_tbl_decoding[rpos[0]] << 2
| base64_url_tbl_decoding[rpos[1]] >> 4);
(*wpos++) = (base64_url_tbl_decoding[rpos[1]] << 4
| base64_url_tbl_decoding[rpos[2]] >> 2);
(*wpos++) = (base64_url_tbl_decoding[rpos[2]] << 6
| base64_url_tbl_decoding[rpos[3]]);
}
/* Tail special decoding. */
switch ((src_size - src_m4_size))
{
case 2:
(*wpos++) = (base64_url_tbl_decoding[rpos[0]] << 2
| base64_url_tbl_decoding[rpos[1]] >> 4);
break;
case 3:
(*wpos++) = (base64_url_tbl_decoding[rpos[0]] << 2
| base64_url_tbl_decoding[rpos[1]] >> 4);
(*wpos++) = (base64_url_tbl_decoding[rpos[1]] << 4
| base64_url_tbl_decoding[rpos[2]] >> 2);
break;
}
(*wpos) = 0;
if (NULL != dcd_size)
{ /* Real decoded size can be smaller than calculated. */
(*dcd_size) = (wpos - dst);
}
return (0);
}
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