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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
|
/* $OpenBSD: roaming_client.c,v 1.1 2009/10/24 11:22:37 andreas Exp $ */
/*
* Copyright (c) 2004-2009 AppGate Network Security AB
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/queue.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <inttypes.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <openssl/crypto.h>
#include <openssl/sha.h>
#include "xmalloc.h"
#include "buffer.h"
#include "channels.h"
#include "cipher.h"
#include "dispatch.h"
#include "clientloop.h"
#include "log.h"
#include "match.h"
#include "misc.h"
#include "packet.h"
#include "ssh.h"
#include "key.h"
#include "kex.h"
#include "readconf.h"
#include "roaming.h"
#include "ssh2.h"
#include "sshconnect.h"
/* import */
extern Options options;
extern char *host;
extern struct sockaddr_storage hostaddr;
extern int session_resumed;
static u_int32_t roaming_id;
static u_int64_t cookie;
static u_int64_t lastseenchall;
static u_int64_t key1, key2, oldkey1, oldkey2;
void
roaming_reply(int type, u_int32_t seq, void *ctxt)
{
if (type == SSH2_MSG_REQUEST_FAILURE) {
logit("Server denied roaming");
return;
}
verbose("Roaming enabled");
roaming_id = packet_get_int();
cookie = packet_get_int64();
key1 = oldkey1 = packet_get_int64();
key2 = oldkey2 = packet_get_int64();
set_out_buffer_size(packet_get_int() + get_snd_buf_size());
roaming_enabled = 1;
}
void
request_roaming(void)
{
packet_start(SSH2_MSG_GLOBAL_REQUEST);
packet_put_cstring(ROAMING_REQUEST);
packet_put_char(1);
packet_put_int(get_recv_buf_size());
packet_send();
client_register_global_confirm(roaming_reply, NULL);
}
static void
roaming_auth_required(void)
{
u_char digest[SHA_DIGEST_LENGTH];
EVP_MD_CTX md;
Buffer b;
const EVP_MD *evp_md = EVP_sha1();
u_int64_t chall, oldchall;
chall = packet_get_int64();
oldchall = packet_get_int64();
if (oldchall != lastseenchall) {
key1 = oldkey1;
key2 = oldkey2;
}
lastseenchall = chall;
buffer_init(&b);
buffer_put_int64(&b, cookie);
buffer_put_int64(&b, chall);
EVP_DigestInit(&md, evp_md);
EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
EVP_DigestFinal(&md, digest, NULL);
buffer_free(&b);
packet_start(SSH2_MSG_KEX_ROAMING_AUTH);
packet_put_int64(key1 ^ get_recv_bytes());
packet_put_raw(digest, sizeof(digest));
packet_send();
oldkey1 = key1;
oldkey2 = key2;
calculate_new_key(&key1, cookie, chall);
calculate_new_key(&key2, cookie, chall);
debug("Received %" PRIu64 " bytes", get_recv_bytes());
debug("Sent roaming_auth packet");
}
int
resume_kex(void)
{
/*
* This should not happen - if the client sends the kex method
* resume@appgate.com then the kex is done in roaming_resume().
*/
return 1;
}
static int
roaming_resume(void)
{
u_int64_t recv_bytes;
char *str = NULL, *kexlist = NULL, *c;
int i, type;
int timeout_ms = options.connection_timeout * 1000;
u_int len;
u_int32_t rnd = 0;
resume_in_progress = 1;
/* Exchange banners */
ssh_exchange_identification(timeout_ms);
packet_set_nonblocking();
/* Send a kexinit message with resume@appgate.com as only kex algo */
packet_start(SSH2_MSG_KEXINIT);
for (i = 0; i < KEX_COOKIE_LEN; i++) {
if (i % 4 == 0)
rnd = arc4random();
packet_put_char(rnd & 0xff);
rnd >>= 8;
}
packet_put_cstring(KEX_RESUME);
for (i = 1; i < PROPOSAL_MAX; i++) {
/* kex algorithm added so start with i=1 and not 0 */
packet_put_cstring(""); /* Not used when we resume */
}
packet_put_char(1); /* first kex_packet follows */
packet_put_int(0); /* reserved */
packet_send();
/* Assume that resume@appgate.com will be accepted */
packet_start(SSH2_MSG_KEX_ROAMING_RESUME);
packet_put_int(roaming_id);
packet_send();
/* Read the server's kexinit and check for resume@appgate.com */
if ((type = packet_read()) != SSH2_MSG_KEXINIT) {
debug("expected kexinit on resume, got %d", type);
goto fail;
}
for (i = 0; i < KEX_COOKIE_LEN; i++)
(void)packet_get_char();
kexlist = packet_get_string(&len);
if (!kexlist
|| (str = match_list(KEX_RESUME, kexlist, NULL)) == NULL) {
debug("server doesn't allow resume");
goto fail;
}
xfree(str);
for (i = 1; i < PROPOSAL_MAX; i++) {
/* kex algorithm taken care of so start with i=1 and not 0 */
xfree(packet_get_string(&len));
}
i = packet_get_char(); /* first_kex_packet_follows */
if (i && (c = strchr(kexlist, ',')))
*c = 0;
if (i && strcmp(kexlist, KEX_RESUME)) {
debug("server's kex guess (%s) was wrong, skipping", kexlist);
(void)packet_read(); /* Wrong guess - discard packet */
}
/*
* Read the ROAMING_AUTH_REQUIRED challenge from the server and
* send ROAMING_AUTH
*/
if ((type = packet_read()) != SSH2_MSG_KEX_ROAMING_AUTH_REQUIRED) {
debug("expected roaming_auth_required, got %d", type);
goto fail;
}
roaming_auth_required();
/* Read ROAMING_AUTH_OK from the server */
if ((type = packet_read()) != SSH2_MSG_KEX_ROAMING_AUTH_OK) {
debug("expected roaming_auth_ok, got %d", type);
goto fail;
}
recv_bytes = packet_get_int64() ^ oldkey2;
debug("Peer received %" PRIu64 " bytes", recv_bytes);
resend_bytes(packet_get_connection_out(), &recv_bytes);
resume_in_progress = 0;
session_resumed = 1; /* Tell clientloop */
return 0;
fail:
if (kexlist)
xfree(kexlist);
if (packet_get_connection_in() == packet_get_connection_out())
close(packet_get_connection_in());
else {
close(packet_get_connection_in());
close(packet_get_connection_out());
}
return 1;
}
int
wait_for_roaming_reconnect(void)
{
static int reenter_guard = 0;
int timeout_ms = options.connection_timeout * 1000;
int c;
if (reenter_guard != 0)
fatal("Server refused resume, roaming timeout may be exceeded");
reenter_guard = 1;
fprintf(stderr, "[connection suspended, press return to resume]");
fflush(stderr);
packet_backup_state();
/* TODO Perhaps we should read from tty here */
while ((c = fgetc(stdin)) != EOF) {
if (c == 'Z' - 64) {
kill(getpid(), SIGTSTP);
continue;
}
if (c != '\n' && c != '\r')
continue;
if (ssh_connect(host, &hostaddr, options.port,
options.address_family, 1, &timeout_ms,
options.tcp_keep_alive, options.use_privileged_port,
options.proxy_command) == 0 && roaming_resume() == 0) {
packet_restore_state();
reenter_guard = 0;
fprintf(stderr, "[connection resumed]\n");
fflush(stderr);
return 0;
}
fprintf(stderr, "[reconnect failed, press return to retry]");
fflush(stderr);
}
fprintf(stderr, "[exiting]\n");
fflush(stderr);
exit(0);
}
|
