cryb-to/lib/enc/cryb_percent.c
Dag-Erling Smørgrav f7bdd342dc Add our own version of <endian.h> which includes implementations of the
unaligned encoding / decoding functions which Linux lacks.
2014-10-30 12:48:21 +00:00

111 lines
3 KiB
C

/*-
* Copyright (c) 2014 Dag-Erling Smørgrav
* 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.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include "cryb/impl.h"
#include <errno.h>
#include <stdint.h>
#include <string.h>
#include <cryb/ctype.h>
#include <cryb/rfc3986.h>
static const char hex[] = "0123456789ABCDEF";
#define unhex(ch) \
((ch >= '0' && ch <= '9') ? ch - '0' : \
(ch >= 'A' && ch <= 'F') ? 0xa + ch - 'A' : \
(ch >= 'a' && ch <= 'f') ? 0xa + ch - 'a' : 0)
/*
* Encodes a string in RFC 3986 percent-encoded representation.
*/
int
percent_encode(const char *in, size_t ilen, char *out, size_t *olen)
{
size_t len;
for (len = 0; ilen && *in; --ilen, ++in) {
if (is_uri(*in)) {
if (len++ < *olen)
*out++ = *in;
} else {
if (len++ < *olen)
*out++ = '%';
if (len++ < *olen)
*out++ = hex[(uint8_t)*in >> 4];
if (len++ < *olen)
*out++ = hex[(uint8_t)*in & 0xf];
}
}
if (len < *olen)
*out = '\0';
if (len >= *olen) {
/* overflow */
*olen = len;
errno = ENOSPC;
return (-1);
}
*olen = len;
return (0);
}
/*
* Decodes a string in RFC 3986 percent-encoded representation.
*/
int
percent_decode(const char *in, size_t ilen, char *out, size_t *olen)
{
size_t len;
for (len = 0; ilen && *in; --ilen, ++in) {
if (*in != '%') {
if (++len < *olen)
*out++ = *in;
} else if (ilen >= 3 && is_xdigit(in[1]) && is_xdigit(in[2])) {
if (++len < *olen)
*out++ = unhex(in[1]) << 4 | unhex(in[2]);
in += 2;
} else {
errno = EINVAL;
return (-1);
}
}
if (len < *olen)
*out = '\0';
if (len >= *olen) {
/* overflow */
*olen = len;
errno = ENOSPC;
return (-1);
}
*olen = len;
return (0);
}