summaryrefslogtreecommitdiff
path: root/src/html/houdini_html_e.c
blob: f2e86fe35bbd0ff76ba95e9de348891808aba6a3 (plain)
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
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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
#include <assert.h>
#include <stdio.h>
#include <string.h>

#include "html/houdini.h"

/**
 * According to the OWASP rules:
 *
 * & --> &amp;
 * < --> &lt;
 * > --> &gt;
 * " --> &quot;
 * ' --> &#x27;     &apos; is not recommended
 * / --> &#x2F;     forward slash is included as it helps end an HTML entity
 *
 */
static const char HTML_ESCAPE_TABLE[] = {
	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, 1, 0, 0, 0, 2, 3, 0, 0, 0, 0, 0, 0, 0, 4,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 6, 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, 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,
};

static const char *HTML_ESCAPES[] = {
        "",
        "&quot;",
        "&amp;",
        "&#39;",
        "&#47;",
        "&lt;",
        "&gt;"
};

int
houdini_escape_html0(strbuf *ob, const uint8_t *src, size_t size, int secure)
{
	size_t  i = 0, org, esc = 0;

	while (i < size) {
		org = i;
		while (i < size && (esc = HTML_ESCAPE_TABLE[src[i]]) == 0)
			i++;

		if (i > org)
			strbuf_put(ob, src + org, i - org);

		/* escaping */
		if (unlikely(i >= size))
			break;

		/* The forward slash is only escaped in secure mode */
		if ((src[i] == '/' || src[i] == '\'') && !secure) {
			strbuf_putc(ob, src[i]);
		} else {
			strbuf_puts(ob, HTML_ESCAPES[esc]);
		}

		i++;
	}

	return 1;
}

int
houdini_escape_html(strbuf *ob, const uint8_t *src, size_t size)
{
	return houdini_escape_html0(ob, src, size, 1);
}