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
143
144
145
|
/*
* Copyright (C) 2010 Martin Willi
* Copyright (C) 2010 revosec AG
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
#include "hook.h"
#include <time.h>
#include <netinet/udp.h>
#include <encoding/payloads/cert_payload.h>
#include <encoding/payloads/encryption_payload.h>
typedef struct private_ike_auth_fill_t private_ike_auth_fill_t;
/**
* Private data of an ike_auth_fill_t object.
*/
struct private_ike_auth_fill_t {
/**
* Implements the hook_t interface.
*/
hook_t hook;
/**
* Alter requests or responses?
*/
bool req;
/**
* ID of message to alter.
*/
int id;
/**
* Number of bytes to fill IKE_AUTH up
*/
int bytes;
};
/** size of non ESP-Marker */
#define NON_ESP_MARKER_LEN 4
/**
* Calculate packet size on wire (without ethernet/IP header)
*/
static size_t calculate_wire_size(message_t *message, ike_sa_t *ike_sa)
{
enumerator_t *enumerator;
payload_t *payload;
size_t size = 0;
enumerator = message->create_payload_enumerator(message);
while (enumerator->enumerate(enumerator, &payload))
{
size += payload->get_length(payload);
}
enumerator->destroy(enumerator);
if (message->get_exchange_type(message) != IKE_SA_INIT)
{
keymat_t *keymat;
aead_t *aead;
size_t bs;
keymat = ike_sa->get_keymat(ike_sa);
aead = keymat->get_aead(keymat, FALSE);
if (aead)
{
bs = aead->get_block_size(aead);
size += ENCRYPTION_PAYLOAD_HEADER_LENGTH + NON_ESP_MARKER_LEN +
aead->get_icv_size(aead) + aead->get_iv_size(aead) +
(bs - (size % bs));
}
}
return sizeof(struct udphdr) + IKE_HEADER_LENGTH + size;
}
METHOD(listener_t, message, bool,
private_ike_auth_fill_t *this, ike_sa_t *ike_sa, message_t *message,
bool incoming)
{
if (!incoming &&
message->get_request(message) == this->req &&
message->get_message_id(message) == this->id)
{
cert_payload_t *pld;
size_t size, diff;
chunk_t data;
size = calculate_wire_size(message, ike_sa);
if (size < this->bytes - CERT_PAYLOAD_HEADER_LENGTH)
{
diff = this->bytes - size - CERT_PAYLOAD_HEADER_LENGTH;
data = chunk_alloc(diff);
memset(data.ptr, 0x12, data.len);
pld = cert_payload_create_custom(201, data);
message->add_payload(message, &pld->payload_interface);
DBG1(DBG_CFG, "inserting %d dummy bytes certificate payload", diff);
}
}
return TRUE;
}
METHOD(hook_t, destroy, void,
private_ike_auth_fill_t *this)
{
free(this);
}
/**
* Create the IKE_AUTH fill hook
*/
hook_t *ike_auth_fill_hook_create(char *name)
{
private_ike_auth_fill_t *this;
INIT(this,
.hook = {
.listener = {
.message = _message,
},
.destroy = _destroy,
},
.req = conftest->test->get_bool(conftest->test,
"hooks.%s.request", TRUE, name),
.id = conftest->test->get_int(conftest->test,
"hooks.%s.id", 1, name),
.bytes = conftest->test->get_int(conftest->test,
"hooks.%s.bytes", 0, name),
);
return &this->hook;
}
|
