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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/*
* Copyright (c) 2015 Balabit
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As an additional exemption you are allowed to compile & link against the
* OpenSSL libraries as published by the OpenSSL project. See the file
* COPYING for details.
*
*/
#include "kv-scanner.h"
#include "utf8utils.h"
#include <string.h>
#include <ctype.h>
const gchar *hexcoded_fields[] =
{
"name",
"proctitle",
"path",
"dir",
"comm",
"ocomm",
"data",
"old",
"new",
NULL
};
static gint
_decode_xdigit(gchar xdigit)
{
if (xdigit >= '0' && xdigit <= '9')
return xdigit - '0';
xdigit = toupper(xdigit);
if (xdigit >= 'A' && xdigit <= 'F')
return xdigit - 'A' + 10;
return -1;
}
static gint
_decode_xbyte(gchar xdigit1, gchar xdigit2)
{
gint nibble_hi, nibble_lo;
nibble_hi = _decode_xdigit(xdigit1);
nibble_lo = _decode_xdigit(xdigit2);
if (nibble_hi < 0 || nibble_lo < 0)
return -1;
return (nibble_hi << 4) + nibble_lo;
}
static gboolean
_is_control_char(gint ch)
{
if (ch < 0x21 || ch > 0x7e)
return TRUE;
return FALSE;
}
static gboolean
_parse_linux_audit_hexstring(GString *decoded_value, const gchar *value, gsize len)
{
gint src;
gboolean kernel_would_have_encoded_this_as_hex = FALSE;
for (src = 0; src < len; src += 2)
{
gint v;
v = _decode_xbyte(value[src], value[src + 1]);
if (v < 0)
return FALSE;
if (_is_control_char(v) || v == '"')
kernel_would_have_encoded_this_as_hex = TRUE;
if (v == 0)
v = '\t';
g_string_append_c(decoded_value, v);
}
if (!kernel_would_have_encoded_this_as_hex)
return FALSE;
return TRUE;
}
static gboolean
_is_field_hex_encoded(const gchar *field)
{
gint i;
if (field[0] == 'a' && isdigit(field[1]))
return TRUE;
for (i = 0; hexcoded_fields[i]; i++)
{
if (strcmp(hexcoded_fields[i], field) == 0)
return TRUE;
}
return FALSE;
}
static gboolean
_parse_linux_audit_style_hexdump(KVScanner *self)
{
if (!self->value_was_quoted &&
(self->value->len % 2) == 0 &&
isxdigit(self->value->str[0]) &&
_is_field_hex_encoded(self->key->str))
{
if (!_parse_linux_audit_hexstring(self->decoded_value, self->value->str, self->value->len))
return FALSE;
if (!g_utf8_validate(self->decoded_value->str, self->decoded_value->len, NULL))
return FALSE;
return TRUE;
}
return FALSE;
}
KVScanner *
linux_audit_scanner_new(void)
{
KVScanner *self = kv_scanner_new();
self->parse_value = _parse_linux_audit_style_hexdump;
return self;
}
|
