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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
/*
* QEMU VNC display driver: VeNCrypt authentication setup
*
* Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
* Copyright (C) 2006 Fabrice Bellard
* Copyright (C) 2009 Red Hat, Inc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "vnc.h"
#include "qemu/main-loop.h"
static void start_auth_vencrypt_subauth(VncState *vs)
{
switch (vs->subauth) {
case VNC_AUTH_VENCRYPT_TLSNONE:
case VNC_AUTH_VENCRYPT_X509NONE:
VNC_DEBUG("Accept TLS auth none\n");
vnc_write_u32(vs, 0); /* Accept auth completion */
start_client_init(vs);
break;
case VNC_AUTH_VENCRYPT_TLSVNC:
case VNC_AUTH_VENCRYPT_X509VNC:
VNC_DEBUG("Start TLS auth VNC\n");
start_auth_vnc(vs);
break;
#ifdef CONFIG_VNC_SASL
case VNC_AUTH_VENCRYPT_TLSSASL:
case VNC_AUTH_VENCRYPT_X509SASL:
VNC_DEBUG("Start TLS auth SASL\n");
start_auth_sasl(vs);
break;
#endif /* CONFIG_VNC_SASL */
default: /* Should not be possible, but just in case */
VNC_DEBUG("Reject subauth %d server bug\n", vs->auth);
vnc_write_u8(vs, 1);
if (vs->minor >= 8) {
static const char err[] = "Unsupported authentication type";
vnc_write_u32(vs, sizeof(err));
vnc_write(vs, err, sizeof(err));
}
vnc_client_error(vs);
}
}
static gboolean vnc_tls_handshake_io(QIOChannel *ioc,
GIOCondition condition,
void *opaque);
static int vnc_start_vencrypt_handshake(VncState *vs)
{
Error *err = NULL;
if (qcrypto_tls_session_handshake(vs->tls, &err) < 0) {
goto error;
}
switch (qcrypto_tls_session_get_handshake_status(vs->tls)) {
case QCRYPTO_TLS_HANDSHAKE_COMPLETE:
VNC_DEBUG("Handshake done, checking credentials\n");
if (qcrypto_tls_session_check_credentials(vs->tls, &err) < 0) {
goto error;
}
VNC_DEBUG("Client verification passed, starting TLS I/O\n");
if (vs->ioc_tag) {
g_source_remove(vs->ioc_tag);
}
vs->ioc_tag = qio_channel_add_watch(
vs->ioc, G_IO_IN | G_IO_OUT, vnc_client_io, vs, NULL);
start_auth_vencrypt_subauth(vs);
break;
case QCRYPTO_TLS_HANDSHAKE_RECVING:
VNC_DEBUG("Handshake interrupted (blocking read)\n");
if (vs->ioc_tag) {
g_source_remove(vs->ioc_tag);
}
vs->ioc_tag = qio_channel_add_watch(
vs->ioc, G_IO_IN, vnc_tls_handshake_io, vs, NULL);
break;
case QCRYPTO_TLS_HANDSHAKE_SENDING:
VNC_DEBUG("Handshake interrupted (blocking write)\n");
if (vs->ioc_tag) {
g_source_remove(vs->ioc_tag);
}
vs->ioc_tag = qio_channel_add_watch(
vs->ioc, G_IO_OUT, vnc_tls_handshake_io, vs, NULL);
break;
}
return 0;
error:
VNC_DEBUG("Handshake failed %s\n", error_get_pretty(err));
error_free(err);
vnc_client_error(vs);
return -1;
}
static gboolean vnc_tls_handshake_io(QIOChannel *ioc G_GNUC_UNUSED,
GIOCondition condition G_GNUC_UNUSED,
void *opaque)
{
VncState *vs = (VncState *)opaque;
VNC_DEBUG("Handshake IO continue\n");
vnc_start_vencrypt_handshake(vs);
return TRUE;
}
static int protocol_client_vencrypt_auth(VncState *vs, uint8_t *data, size_t len)
{
int auth = read_u32(data, 0);
if (auth != vs->subauth) {
VNC_DEBUG("Rejecting auth %d\n", auth);
vnc_write_u8(vs, 0); /* Reject auth */
vnc_flush(vs);
vnc_client_error(vs);
} else {
Error *err = NULL;
VNC_DEBUG("Accepting auth %d, setting up TLS for handshake\n", auth);
vnc_write_u8(vs, 1); /* Accept auth */
vnc_flush(vs);
vs->tls = qcrypto_tls_session_new(vs->vd->tlscreds,
NULL,
vs->vd->tlsaclname,
QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
&err);
if (!vs->tls) {
VNC_DEBUG("Failed to setup TLS %s\n",
error_get_pretty(err));
error_free(err);
vnc_client_error(vs);
return 0;
}
qcrypto_tls_session_set_callbacks(vs->tls,
vnc_tls_push,
vnc_tls_pull,
vs);
VNC_DEBUG("Start TLS VeNCrypt handshake process\n");
if (vnc_start_vencrypt_handshake(vs) < 0) {
VNC_DEBUG("Failed to start TLS handshake\n");
return 0;
}
}
return 0;
}
static int protocol_client_vencrypt_init(VncState *vs, uint8_t *data, size_t len)
{
if (data[0] != 0 ||
data[1] != 2) {
VNC_DEBUG("Unsupported VeNCrypt protocol %d.%d\n", (int)data[0], (int)data[1]);
vnc_write_u8(vs, 1); /* Reject version */
vnc_flush(vs);
vnc_client_error(vs);
} else {
VNC_DEBUG("Sending allowed auth %d\n", vs->subauth);
vnc_write_u8(vs, 0); /* Accept version */
vnc_write_u8(vs, 1); /* Number of sub-auths */
vnc_write_u32(vs, vs->subauth); /* The supported auth */
vnc_flush(vs);
vnc_read_when(vs, protocol_client_vencrypt_auth, 4);
}
return 0;
}
void start_auth_vencrypt(VncState *vs)
{
/* Send VeNCrypt version 0.2 */
vnc_write_u8(vs, 0);
vnc_write_u8(vs, 2);
vnc_read_when(vs, protocol_client_vencrypt_init, 2);
}
|
