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
|
/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 2019-2022 Todd C. Miller <Todd.Miller@sudo.ws>
*
* 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.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include <config.h>
#include <errno.h>
#ifdef HAVE_STDBOOL_H
# include <stdbool.h>
#else
# include <compat/stdbool.h>
#endif /* HAVE_STDBOOL_H */
#if defined(HAVE_STDINT_H)
# include <stdint.h>
#elif defined(HAVE_INTTYPES_H)
# include <inttypes.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sudo_compat.h>
#include <sudo_debug.h>
#include <sudo_event.h>
#include <sudo_fatal.h>
#include <sudo_gettext.h>
#include <sudo_util.h>
#include "logsrv_util.h"
#include <tls_common.h>
#include <hostcheck.h>
#if defined(HAVE_OPENSSL)
/*
* Check that the server's certificate is valid that it contains the
* server name or IP address.
* Returns 0 if the cert is invalid, else 1.
*/
static int
verify_peer_identity(int preverify_ok, X509_STORE_CTX *ctx)
{
HostnameValidationResult result;
struct peer_info *peer_info;
SSL *ssl;
X509 *current_cert;
X509 *peer_cert;
debug_decl(verify_peer_identity, SUDO_DEBUG_UTIL);
/* if pre-verification of the cert failed, just propagate that result back */
if (preverify_ok != 1) {
debug_return_int(0);
}
/*
* Since this callback is called for each cert in the chain,
* check that current cert is the peer's certificate
*/
current_cert = X509_STORE_CTX_get_current_cert(ctx);
peer_cert = X509_STORE_CTX_get0_cert(ctx);
if (current_cert != peer_cert) {
debug_return_int(1);
}
/* Fetch the attached peer_info from the ssl connection object. */
ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx());
peer_info = SSL_get_ex_data(ssl, 1);
/*
* Validate the cert based on the host name and IP address.
* If host name is not known, validate_hostname() can resolve it.
*/
result = validate_hostname(peer_cert,
peer_info->name ? peer_info->name : peer_info->ipaddr,
peer_info->ipaddr, peer_info->name ? 0 : 1);
debug_return_int(result == MatchFound);
}
void
tls_connect_cb(int sock, int what, void *v)
{
struct tls_client_closure *tls_client = v;
struct sudo_event_base *evbase = tls_client->evbase;
const struct timespec *timeout = &tls_client->connect_timeout;
const char *errstr;
int con_stat;
debug_decl(tls_connect_cb, SUDO_DEBUG_UTIL);
if (what == SUDO_EV_TIMEOUT) {
sudo_warnx("%s", U_("TLS handshake timeout occurred"));
goto bad;
}
con_stat = SSL_connect(tls_client->ssl);
if (con_stat == 1) {
sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
"SSL_connect successful");
tls_client->tls_connect_state = true;
} else {
switch (SSL_get_error(tls_client->ssl, con_stat)) {
/* TLS handshake is not finished, reschedule event */
case SSL_ERROR_WANT_READ:
sudo_debug_printf(SUDO_DEBUG_NOTICE|SUDO_DEBUG_LINENO,
"SSL_connect returns SSL_ERROR_WANT_READ");
if (what != SUDO_EV_READ) {
if (sudo_ev_set(tls_client->tls_connect_ev,
SSL_get_fd(tls_client->ssl), SUDO_EV_READ,
tls_connect_cb, tls_client) == -1) {
sudo_warnx("%s", U_("unable to set event"));
goto bad;
}
}
if (sudo_ev_add(evbase, tls_client->tls_connect_ev, timeout, false) == -1) {
sudo_warnx("%s", U_("unable to add event to queue"));
goto bad;
}
break;
case SSL_ERROR_WANT_WRITE:
sudo_debug_printf(SUDO_DEBUG_NOTICE|SUDO_DEBUG_LINENO,
"SSL_connect returns SSL_ERROR_WANT_WRITE");
if (what != SUDO_EV_WRITE) {
if (sudo_ev_set(tls_client->tls_connect_ev,
SSL_get_fd(tls_client->ssl), SUDO_EV_WRITE,
tls_connect_cb, tls_client) == -1) {
sudo_warnx("%s", U_("unable to set event"));
goto bad;
}
}
if (sudo_ev_add(evbase, tls_client->tls_connect_ev, timeout, false) == -1) {
sudo_warnx("%s", U_("unable to add event to queue"));
goto bad;
}
break;
case SSL_ERROR_SYSCALL:
sudo_warnx(U_("TLS connection failed: %s"), strerror(errno));
goto bad;
default:
errstr = ERR_reason_error_string(ERR_get_error());
sudo_warnx(U_("TLS connection failed: %s"),
errstr ? errstr : strerror(errno));
goto bad;
}
}
if (tls_client->tls_connect_state) {
sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
"TLS version: %s, negotiated cipher suite: %s",
SSL_get_version(tls_client->ssl), SSL_get_cipher(tls_client->ssl));
/* Done with TLS connect, send ClientHello */
sudo_ev_free(tls_client->tls_connect_ev);
tls_client->tls_connect_ev = NULL;
if (!tls_client->start_fn(tls_client))
goto bad;
}
debug_return;
bad:
sudo_ev_loopbreak(evbase);
debug_return;
}
bool
tls_ctx_client_setup(SSL_CTX *ssl_ctx, int sock,
struct tls_client_closure *closure)
{
const char *errstr;
bool ret = false;
debug_decl(tls_ctx_client_setup, SUDO_DEBUG_UTIL);
if ((closure->ssl = SSL_new(ssl_ctx)) == NULL) {
errstr = ERR_reason_error_string(ERR_get_error());
sudo_warnx(U_("unable to allocate ssl object: %s"),
errstr ? errstr : strerror(errno));
goto done;
}
if (SSL_set_ex_data(closure->ssl, 1, closure->peer_name) <= 0) {
errstr = ERR_reason_error_string(ERR_get_error());
sudo_warnx(U_("Unable to attach user data to the ssl object: %s"),
errstr ? errstr : strerror(errno));
goto done;
}
if (SSL_set_fd(closure->ssl, sock) <= 0) {
errstr = ERR_reason_error_string(ERR_get_error());
sudo_warnx(U_("Unable to attach socket to the ssl object: %s"),
errstr ? errstr : strerror(errno));
goto done;
}
if (sudo_ev_add(closure->evbase, closure->tls_connect_ev, NULL, false) == -1) {
sudo_warnx("%s", U_("unable to add event to queue"));
goto done;
}
ret = true;
done:
debug_return_bool(ret);
}
bool
tls_client_setup(int sock, const char *ca_bundle_file, const char *cert_file,
const char *key_file, const char *dhparam_file, const char *ciphers_v12,
const char *ciphers_v13, bool verify_server, bool check_peer,
struct tls_client_closure *closure)
{
SSL_CTX *ssl_ctx;
debug_decl(tls_client_setup, SUDO_DEBUG_UTIL);
ssl_ctx = init_tls_context(ca_bundle_file, cert_file, key_file,
dhparam_file, ciphers_v12, ciphers_v13, verify_server);
if (ssl_ctx == NULL) {
sudo_warnx("%s", U_("unable to initialize TLS context"));
debug_return_bool(false);
}
if (check_peer) {
/* Verify server cert during the handshake. */
SSL_CTX_set_verify(ssl_ctx,
SSL_VERIFY_PEER|SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
verify_peer_identity);
}
debug_return_bool(tls_ctx_client_setup(ssl_ctx, sock, closure));
}
#endif /* HAVE_OPENSSL */
|
