112 lines
3.2 KiB
C
112 lines
3.2 KiB
C
|
#include <assert.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <string.h>
|
||
|
|
|
||
|
|
#include "houdini.h"
|
||
|
|
|
||
|
|
#define ESCAPE_GROW_FACTOR( x ) ( ( (x) * 12 ) / 10 )
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The following characters will not be escaped:
|
||
|
|
*
|
||
|
|
* -_.+!*'(),%#@?=;:/,+&$ alphanum
|
||
|
|
*
|
||
|
|
* Note that this character set is the addition of:
|
||
|
|
*
|
||
|
|
* - The characters which are safe to be in an URL
|
||
|
|
* - The characters which are *not* safe to be in
|
||
|
|
* an URL because they are RESERVED characters.
|
||
|
|
*
|
||
|
|
* We asume (lazily) that any RESERVED char that
|
||
|
|
* appears inside an URL is actually meant to
|
||
|
|
* have its native function (i.e. as an URL
|
||
|
|
* component/separator) and hence needs no escaping.
|
||
|
|
*
|
||
|
|
* There are two exceptions: the chacters & (amp)
|
||
|
|
* and ' (single quote) do not appear in the table.
|
||
|
|
* They are meant to appear in the URL as components,
|
||
|
|
* yet they require special HTML-entity escaping
|
||
|
|
* to generate valid HTML markup.
|
||
|
|
*
|
||
|
|
* All other characters will be escaped to %XX.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
static const char HREF_SAFE[] =
|
||
|
|
{
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
|
||
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1,
|
||
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
|
||
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,
|
||
|
|
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
|
||
|
|
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
||
|
|
};
|
||
|
|
|
||
|
|
void houdini_escape_href( struct buf* ob, const uint8_t* src, size_t size )
|
||
|
|
{
|
||
|
|
static const char hex_chars[] = "0123456789ABCDEF";
|
||
|
|
size_t i = 0, org;
|
||
|
|
char hex_str[3];
|
||
|
|
|
||
|
|
bufgrow( ob, ESCAPE_GROW_FACTOR( size ) );
|
||
|
|
hex_str[0] = '%';
|
||
|
|
|
||
|
|
while( i < size )
|
||
|
|
{
|
||
|
|
org = i;
|
||
|
|
|
||
|
|
while( i < size && HREF_SAFE[src[i]] != 0 )
|
||
|
|
i++;
|
||
|
|
|
||
|
|
if( i > org )
|
||
|
|
bufput( ob, src + org, i - org );
|
||
|
|
|
||
|
|
/* escaping */
|
||
|
|
if( i >= size )
|
||
|
|
break;
|
||
|
|
|
||
|
|
switch( src[i] )
|
||
|
|
{
|
||
|
|
/* amp appears all the time in URLs, but needs
|
||
|
|
* HTML-entity escaping to be inside an href */
|
||
|
|
case '&':
|
||
|
|
BUFPUTSL( ob, "&" );
|
||
|
|
break;
|
||
|
|
|
||
|
|
/* the single quote is a valid URL character
|
||
|
|
* according to the standard; it needs HTML
|
||
|
|
* entity escaping too */
|
||
|
|
case '\'':
|
||
|
|
BUFPUTSL( ob, "'" );
|
||
|
|
break;
|
||
|
|
|
||
|
|
/* the space can be escaped to %20 or a plus
|
||
|
|
* sign. we're going with the generic escape
|
||
|
|
* for now. the plus thing is more commonly seen
|
||
|
|
* when building GET strings */
|
||
|
|
#if 0
|
||
|
|
case ' ':
|
||
|
|
bufputc( ob, '+' );
|
||
|
|
break;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* every other character goes with a %XX escaping */
|
||
|
|
default:
|
||
|
|
hex_str[1] = hex_chars[(src[i] >> 4) & 0xF];
|
||
|
|
hex_str[2] = hex_chars[src[i] & 0xF];
|
||
|
|
bufput( ob, hex_str, 3 );
|
||
|
|
}
|
||
|
|
|
||
|
|
i++;
|
||
|
|
}
|
||
|
|
}
|