codebox/url/url.c

/*
   +----------------------------------------------------------------------+
   | PHP Version 7                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2018 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Author: Jim Winstead <jimw@php.net>                                  |
   +----------------------------------------------------------------------+
 */

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>

char *replace_controlchars_ex(char *str, size_t len)
{
	unsigned char *s = (unsigned char *)str;
	unsigned char *e = (unsigned char *)str + len;

	if (!str) {
		return (NULL);
	}

	while (s < e) {

		if (iscntrl(*s)) {
			*s='_';
		}
		s++;
	}

	return (str);
}

char *replace_controlchars(char *str)
{
	return replace_controlchars_ex(str, strlen(str));
}


static int htoi(char *s)
{
	int value;
	int c;

	c = ((unsigned char *)s)[0];
	if (isupper(c))
		c = tolower(c);
	value = (c >= '0' && c <= '9' ? c - '0' : c - 'a' + 10) * 16;

	c = ((unsigned char *)s)[1];
	if (isupper(c))
		c = tolower(c);
	value += c >= '0' && c <= '9' ? c - '0' : c - 'a' + 10;

	return (value);
}

/* rfc1738:

   ...The characters ";",
   "/", "?", ":", "@", "=" and "&" are the characters which may be
   reserved for special meaning within a scheme...

   ...Thus, only alphanumerics, the special characters "$-_.+!*'(),", and
   reserved characters used for their reserved purposes may be used
   unencoded within a URL...

   For added safety, we only leave -_. unencoded.
 */

static unsigned char hexchars[] = "0123456789ABCDEF";

void url_encode(char const *s, size_t len, char *out, size_t *out_len)
{
	register unsigned char c;
	unsigned char *to;
	unsigned char const *from, *end;

	from = (unsigned char *)s;
	end = (unsigned char *)s + len;
	to = (unsigned char *)out;

	while (from < end) {
		c = *from++;

		if (c == ' ') {
			*to++ = '+';
		} else if ((c < '0' && c != '-' && c != '.') ||
				   (c < 'A' && c > '9') ||
				   (c > 'Z' && c < 'a' && c != '_') ||
				   (c > 'z')) {
			to[0] = '%';
			to[1] = hexchars[c >> 4];
			to[2] = hexchars[c & 15];
			to += 3;
		} else {
			*to++ = c;
		}
	}
	*to = '\0';
	*out_len = (char *)to - out;
}

void url_decode(char *str, size_t len, char *out, size_t *out_len)
{
	char *data = str;
	char *dest = out;

	while (len--) {
		if (*data == '+') {
			*dest = ' ';
		}
		else if (*data == '%' && len >= 2 && isxdigit((int) *(data + 1))
				 && isxdigit((int) *(data + 2))) {
			*dest = (char) htoi(data + 1);
			data += 2;
			len -= 2;
		} else {
			*dest = *data;
		}
		data++;
		dest++;
	}
	*dest = '\0';
	*out_len = dest - out;
}

void raw_url_encode(char const *s, size_t len, char *out, size_t *out_len)
{
	register size_t x, y;
	char *ret = out;

	for (x = 0, y = 0; len--; x++, y++) {
		char c = s[x];

		ret[y] = c;
		if ((c < '0' && c != '-' &&  c != '.') ||
			(c < 'A' && c > '9') ||
			(c > 'Z' && c < 'a' && c != '_') ||
			(c > 'z' && c != '~')) {
			ret[y++] = '%';
			ret[y++] = hexchars[(unsigned char) c >> 4];
			ret[y] = hexchars[(unsigned char) c & 15];
		}
	}
	ret[y] = '\0';
	*out_len = ret - out;
}

void raw_url_decode(char *str, size_t len, char *out, size_t *out_len)
{
	char *dest = out;
	char *data = str;

	while (len--) {
		if (*data == '%' && len >= 2 && isxdigit((int) *(data + 1))
			&& isxdigit((int) *(data + 2))) {
			*dest = (char) htoi(data + 1);
			data += 2;
			len -= 2;
		} else {
			*dest = *data;
		}
		data++;
		dest++;
	}
	*dest = '\0';
	*out_len = dest - out;
}


/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: sw=4 ts=4 fdm=marker
 * vim<600: sw=4 ts=4
 */