diff options
author | Damien Miller <djm@mindrot.org> | 1999-11-25 00:26:21 +1100 |
---|---|---|
committer | Damien Miller <djm@mindrot.org> | 1999-11-25 00:26:21 +1100 |
commit | 95def09838fc61b37b6ea7cd5c234a465b4b129b (patch) | |
tree | 042744f76f40a326b873cb1c3690a6d7d966bc3e /sshd.c | |
parent | 4d2f15f895f4c795afc008aeff3fd2ceffbc44f4 (diff) |
- Merged very large OpenBSD source code reformat
- OpenBSD CVS updates
- [channels.c cipher.c compat.c log-client.c scp.c serverloop.c]
[ssh.h sshd.8 sshd.c]
syslog changes:
* Unified Logmessage for all auth-types, for success and for failed
* Standard connections get only ONE line in the LOG when level==LOG:
Auth-attempts are logged only, if authentication is:
a) successfull or
b) with passwd or
c) we had more than AUTH_FAIL_LOG failues
* many log() became verbose()
* old behaviour with level=VERBOSE
- [readconf.c readconf.h ssh.1 ssh.h sshconnect.c sshd.c]
tranfer s/key challenge/response data in SSH_SMSG_AUTH_TIS_CHALLENGE
messages. allows use of s/key in windows (ttssh, securecrt) and
ssh-1.2.27 clients without 'ssh -v', ok: niels@
- [sshd.8]
-V, for fallback to openssh in SSH2 compatibility mode
- [sshd.c]
fix sigchld race; cjc5@po.cwru.edu
Diffstat (limited to 'sshd.c')
-rw-r--r-- | sshd.c | 4503 |
1 files changed, 2252 insertions, 2251 deletions
@@ -1,24 +1,17 @@ | |||
1 | /* | 1 | /* |
2 | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | sshd.c | 3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
4 | 4 | * All rights reserved | |
5 | Author: Tatu Ylonen <ylo@cs.hut.fi> | 5 | * Created: Fri Mar 17 17:09:28 1995 ylo |
6 | 6 | * This program is the ssh daemon. It listens for connections from clients, and | |
7 | Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | 7 | * performs authentication, executes use commands or shell, and forwards |
8 | All rights reserved | 8 | * information to/from the application to the user client over an encrypted |
9 | 9 | * connection. This can also handle forwarding of X11, TCP/IP, and authentication | |
10 | Created: Fri Mar 17 17:09:28 1995 ylo | 10 | * agent connections. |
11 | 11 | */ | |
12 | This program is the ssh daemon. It listens for connections from clients, and | ||
13 | performs authentication, executes use commands or shell, and forwards | ||
14 | information to/from the application to the user client over an encrypted | ||
15 | connection. This can also handle forwarding of X11, TCP/IP, and authentication | ||
16 | agent connections. | ||
17 | |||
18 | */ | ||
19 | 12 | ||
20 | #include "includes.h" | 13 | #include "includes.h" |
21 | RCSID("$Id: sshd.c,v 1.29 1999/11/23 00:24:32 damien Exp $"); | 14 | RCSID("$Id: sshd.c,v 1.30 1999/11/24 13:26:23 damien Exp $"); |
22 | 15 | ||
23 | #include "xmalloc.h" | 16 | #include "xmalloc.h" |
24 | #include "rsa.h" | 17 | #include "rsa.h" |
@@ -52,10 +45,12 @@ ServerOptions options; | |||
52 | /* Name of the server configuration file. */ | 45 | /* Name of the server configuration file. */ |
53 | char *config_file_name = SERVER_CONFIG_FILE; | 46 | char *config_file_name = SERVER_CONFIG_FILE; |
54 | 47 | ||
55 | /* Debug mode flag. This can be set on the command line. If debug | 48 | /* |
56 | mode is enabled, extra debugging output will be sent to the system | 49 | * Debug mode flag. This can be set on the command line. If debug |
57 | log, the daemon will not go to background, and will exit after processing | 50 | * mode is enabled, extra debugging output will be sent to the system |
58 | the first connection. */ | 51 | * log, the daemon will not go to background, and will exit after processing |
52 | * the first connection. | ||
53 | */ | ||
59 | int debug_flag = 0; | 54 | int debug_flag = 0; |
60 | 55 | ||
61 | /* Flag indicating that the daemon is being started from inetd. */ | 56 | /* Flag indicating that the daemon is being started from inetd. */ |
@@ -74,15 +69,21 @@ char **saved_argv; | |||
74 | the SIGHUP signal handler. */ | 69 | the SIGHUP signal handler. */ |
75 | int listen_sock; | 70 | int listen_sock; |
76 | 71 | ||
77 | /* Flags set in auth-rsa from authorized_keys flags. These are set in | 72 | /* the client's version string, passed by sshd2 in compat mode. |
78 | auth-rsa.c. */ | 73 | if != NULL, sshd will skip the version-number exchange */ |
74 | char *client_version_string = NULL; | ||
75 | |||
76 | /* Flags set in auth-rsa from authorized_keys flags. These are set in auth-rsa.c. */ | ||
79 | int no_port_forwarding_flag = 0; | 77 | int no_port_forwarding_flag = 0; |
80 | int no_agent_forwarding_flag = 0; | 78 | int no_agent_forwarding_flag = 0; |
81 | int no_x11_forwarding_flag = 0; | 79 | int no_x11_forwarding_flag = 0; |
82 | int no_pty_flag = 0; | 80 | int no_pty_flag = 0; |
83 | char *forced_command = NULL; /* RSA authentication "command=" option. */ | 81 | |
84 | struct envstring *custom_environment = NULL; | 82 | /* RSA authentication "command=" option. */ |
85 | /* RSA authentication "environment=" options. */ | 83 | char *forced_command = NULL; |
84 | |||
85 | /* RSA authentication "environment=" options. */ | ||
86 | struct envstring *custom_environment = NULL; | ||
86 | 87 | ||
87 | /* Session id for the current session. */ | 88 | /* Session id for the current session. */ |
88 | unsigned char session_id[16]; | 89 | unsigned char session_id[16]; |
@@ -93,13 +94,9 @@ unsigned char session_id[16]; | |||
93 | The private key contains BIGNUMs, and we do not (in principle) have | 94 | The private key contains BIGNUMs, and we do not (in principle) have |
94 | access to the internals of them, and locking just the structure is not | 95 | access to the internals of them, and locking just the structure is not |
95 | very useful. Currently, memory locking is not implemented. */ | 96 | very useful. Currently, memory locking is not implemented. */ |
96 | struct | 97 | struct { |
97 | { | 98 | RSA *private_key; /* Private part of server key. */ |
98 | /* Private part of server key. */ | 99 | RSA *host_key; /* Private part of host key. */ |
99 | RSA *private_key; | ||
100 | |||
101 | /* Private part of host key. */ | ||
102 | RSA *host_key; | ||
103 | } sensitive_data; | 100 | } sensitive_data; |
104 | 101 | ||
105 | /* Flag indicating whether the current session key has been used. This flag | 102 | /* Flag indicating whether the current session key has been used. This flag |
@@ -116,2454 +113,2458 @@ RSA *public_key; | |||
116 | /* Prototypes for various functions defined later in this file. */ | 113 | /* Prototypes for various functions defined later in this file. */ |
117 | void do_connection(); | 114 | void do_connection(); |
118 | void do_authentication(char *user); | 115 | void do_authentication(char *user); |
119 | void do_authloop(struct passwd *pw); | 116 | void do_authloop(struct passwd * pw); |
120 | void do_fake_authloop(char *user); | 117 | void do_fake_authloop(char *user); |
121 | void do_authenticated(struct passwd *pw); | 118 | void do_authenticated(struct passwd * pw); |
122 | void do_exec_pty(const char *command, int ptyfd, int ttyfd, | 119 | void do_exec_pty(const char *command, int ptyfd, int ttyfd, |
123 | const char *ttyname, struct passwd *pw, const char *term, | 120 | const char *ttyname, struct passwd * pw, const char *term, |
124 | const char *display, const char *auth_proto, | 121 | const char *display, const char *auth_proto, |
125 | const char *auth_data); | 122 | const char *auth_data); |
126 | void do_exec_no_pty(const char *command, struct passwd *pw, | 123 | void do_exec_no_pty(const char *command, struct passwd * pw, |
127 | const char *display, const char *auth_proto, | 124 | const char *display, const char *auth_proto, |
128 | const char *auth_data); | 125 | const char *auth_data); |
129 | void do_child(const char *command, struct passwd *pw, const char *term, | 126 | void do_child(const char *command, struct passwd * pw, const char *term, |
130 | const char *display, const char *auth_proto, | 127 | const char *display, const char *auth_proto, |
131 | const char *auth_data, const char *ttyname); | 128 | const char *auth_data, const char *ttyname); |
132 | 129 | ||
133 | #ifdef HAVE_LIBPAM | 130 | #ifdef HAVE_LIBPAM |
134 | static int pamconv(int num_msg, const struct pam_message **msg, | 131 | static int pamconv(int num_msg, const struct pam_message **msg, |
135 | struct pam_response **resp, void *appdata_ptr); | 132 | struct pam_response **resp, void *appdata_ptr); |
136 | void do_pam_account_and_session(char *username, char *remote_user, | 133 | void do_pam_account_and_session(char *username, char *remote_user, |
137 | const char *remote_host); | 134 | const char *remote_host); |
138 | void pam_cleanup_proc(void *context); | 135 | void pam_cleanup_proc(void *context); |
139 | 136 | ||
140 | static struct pam_conv conv = { | 137 | static struct pam_conv conv = { |
141 | pamconv, | 138 | pamconv, |
142 | NULL | 139 | NULL |
143 | }; | 140 | }; |
144 | struct pam_handle_t *pamh = NULL; | 141 | struct pam_handle_t *pamh = NULL; |
145 | const char *pampasswd = NULL; | 142 | const char *pampasswd = NULL; |
146 | char *pamconv_msg = NULL; | 143 | char *pamconv_msg = NULL; |
147 | 144 | ||
148 | static int pamconv(int num_msg, const struct pam_message **msg, | 145 | static int pamconv(int num_msg, const struct pam_message **msg, |
149 | struct pam_response **resp, void *appdata_ptr) | 146 | struct pam_response **resp, void *appdata_ptr) |
150 | { | 147 | { |
151 | struct pam_response *reply; | 148 | struct pam_response *reply; |
152 | int count; | 149 | int count; |
153 | size_t msg_len; | 150 | size_t msg_len; |
154 | char *p; | 151 | char *p; |
155 | 152 | ||
156 | /* PAM will free this later */ | 153 | /* PAM will free this later */ |
157 | reply = malloc(num_msg * sizeof(*reply)); | 154 | reply = malloc(num_msg * sizeof(*reply)); |
158 | if (reply == NULL) | 155 | if (reply == NULL) |
159 | return PAM_CONV_ERR; | 156 | return PAM_CONV_ERR; |
160 | 157 | ||
161 | for(count = 0; count < num_msg; count++) | 158 | for(count = 0; count < num_msg; count++) { |
162 | { | 159 | switch (msg[count]->msg_style) { |
163 | switch (msg[count]->msg_style) | 160 | case PAM_PROMPT_ECHO_OFF: |
164 | { | 161 | if (pampasswd == NULL) { |
165 | case PAM_PROMPT_ECHO_OFF: | 162 | free(reply); |
166 | if (pampasswd == NULL) | 163 | return PAM_CONV_ERR; |
167 | { | 164 | } |
168 | free(reply); | 165 | reply[count].resp_retcode = PAM_SUCCESS; |
169 | return PAM_CONV_ERR; | 166 | reply[count].resp = xstrdup(pampasswd); |
170 | } | 167 | break; |
171 | reply[count].resp_retcode = PAM_SUCCESS; | 168 | |
172 | reply[count].resp = xstrdup(pampasswd); | 169 | case PAM_TEXT_INFO: |
173 | break; | 170 | reply[count].resp_retcode = PAM_SUCCESS; |
174 | 171 | reply[count].resp = xstrdup(""); | |
175 | case PAM_TEXT_INFO: | 172 | |
176 | reply[count].resp_retcode = PAM_SUCCESS; | 173 | if (msg[count]->msg == NULL) |
177 | reply[count].resp = xstrdup(""); | 174 | break; |
178 | 175 | ||
179 | if (msg[count]->msg == NULL) | 176 | debug("Adding PAM message: %s", msg[count]->msg); |
180 | break; | 177 | |
181 | debug("Adding PAM message: %s", msg[count]->msg); | 178 | msg_len = strlen(msg[count]->msg); |
182 | 179 | if (pamconv_msg) { | |
183 | msg_len = strlen(msg[count]->msg); | 180 | size_t n = strlen(pamconv_msg); |
184 | if (pamconv_msg) | 181 | pamconv_msg = xrealloc(pamconv_msg, n + msg_len + 2); |
185 | { | 182 | p = pamconv_msg + n; |
186 | size_t n = strlen(pamconv_msg); | 183 | } else { |
187 | pamconv_msg = xrealloc(pamconv_msg, n + msg_len + 2); | 184 | pamconv_msg = p = xmalloc(msg_len + 2); |
188 | p = pamconv_msg + n; | 185 | } |
186 | memcpy(p, msg[count]->msg, msg_len); | ||
187 | p[msg_len] = '\n'; | ||
188 | p[msg_len + 1] = '\0'; | ||
189 | break; | ||
190 | |||
191 | case PAM_PROMPT_ECHO_ON: | ||
192 | case PAM_ERROR_MSG: | ||
193 | default: | ||
194 | free(reply); | ||
195 | return PAM_CONV_ERR; | ||
196 | } | ||
189 | } | 197 | } |
190 | else | 198 | |
191 | pamconv_msg = p = xmalloc(msg_len + 2); | 199 | *resp = reply; |
192 | memcpy(p, msg[count]->msg, msg_len); | 200 | |
193 | p[msg_len] = '\n'; | 201 | return PAM_SUCCESS; |
194 | p[msg_len + 1] = '\0'; | ||
195 | break; | ||
196 | |||
197 | case PAM_PROMPT_ECHO_ON: | ||
198 | case PAM_ERROR_MSG: | ||
199 | default: | ||
200 | free(reply); | ||
201 | return PAM_CONV_ERR; | ||
202 | } | ||
203 | } | ||
204 | |||
205 | *resp = reply; | ||
206 | |||
207 | return PAM_SUCCESS; | ||
208 | } | 202 | } |
209 | 203 | ||
210 | void pam_cleanup_proc(void *context) | 204 | void pam_cleanup_proc(void *context) |
211 | { | 205 | { |
212 | int pam_retval; | 206 | int pam_retval; |
213 | 207 | ||
214 | if (pamh != NULL) | 208 | if (pamh != NULL) |
215 | { | 209 | { |
216 | pam_retval = pam_close_session((pam_handle_t *)pamh, 0); | 210 | pam_retval = pam_close_session((pam_handle_t *)pamh, 0); |
217 | if (pam_retval != PAM_SUCCESS) | 211 | if (pam_retval != PAM_SUCCESS) { |
218 | { | 212 | log("Cannot close PAM session: %.200s", |
219 | log("Cannot close PAM session: %.200s", | 213 | PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); |
220 | PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); | 214 | } |
221 | } | 215 | |
222 | 216 | pam_retval = pam_end((pam_handle_t *)pamh, pam_retval); | |
223 | pam_retval = pam_end((pam_handle_t *)pamh, pam_retval); | 217 | if (pam_retval != PAM_SUCCESS) { |
224 | if (pam_retval != PAM_SUCCESS) | 218 | log("Cannot release PAM authentication: %.200s", |
225 | { | 219 | PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); |
226 | log("Cannot release PAM authentication: %.200s", | 220 | } |
227 | PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); | 221 | } |
228 | } | ||
229 | } | ||
230 | } | 222 | } |
231 | 223 | ||
232 | void do_pam_account_and_session(char *username, char *remote_user, | 224 | void do_pam_account_and_session(char *username, char *remote_user, |
233 | const char *remote_host) | 225 | const char *remote_host) |
234 | { | 226 | { |
235 | int pam_retval; | 227 | int pam_retval; |
236 | 228 | ||
237 | if (remote_host != NULL) | 229 | if (remote_host != NULL) { |
238 | { | 230 | debug("PAM setting rhost to \"%.200s\"", remote_host); |
239 | debug("PAM setting rhost to \"%.200s\"", remote_host); | 231 | pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RHOST, remote_host); |
240 | pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RHOST, remote_host); | 232 | if (pam_retval != PAM_SUCCESS) { |
241 | if (pam_retval != PAM_SUCCESS) | 233 | log("PAM set rhost failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); |
242 | { | 234 | do_fake_authloop(username); |
243 | log("PAM set rhost failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); | 235 | } |
244 | do_fake_authloop(username); | 236 | } |
245 | } | 237 | |
246 | } | 238 | if (remote_user != NULL) { |
247 | 239 | debug("PAM setting ruser to \"%.200s\"", remote_user); | |
248 | if (remote_user != NULL) | 240 | pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RUSER, remote_user); |
249 | { | 241 | if (pam_retval != PAM_SUCCESS) { |
250 | debug("PAM setting ruser to \"%.200s\"", remote_user); | 242 | log("PAM set ruser failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); |
251 | pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RUSER, remote_user); | 243 | do_fake_authloop(username); |
252 | if (pam_retval != PAM_SUCCESS) | 244 | } |
253 | { | 245 | } |
254 | log("PAM set ruser failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); | 246 | |
255 | do_fake_authloop(username); | 247 | pam_retval = pam_acct_mgmt((pam_handle_t *)pamh, 0); |
256 | } | 248 | if (pam_retval != PAM_SUCCESS) { |
257 | } | 249 | log("PAM rejected by account configuration: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); |
258 | 250 | do_fake_authloop(username); | |
259 | pam_retval = pam_acct_mgmt((pam_handle_t *)pamh, 0); | 251 | } |
260 | if (pam_retval != PAM_SUCCESS) | 252 | |
261 | { | 253 | pam_retval = pam_open_session((pam_handle_t *)pamh, 0); |
262 | log("PAM rejected by account configuration: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); | 254 | if (pam_retval != PAM_SUCCESS) { |
263 | do_fake_authloop(username); | 255 | log("PAM session setup failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); |
264 | } | 256 | do_fake_authloop(username); |
265 | 257 | } | |
266 | pam_retval = pam_open_session((pam_handle_t *)pamh, 0); | ||
267 | if (pam_retval != PAM_SUCCESS) | ||
268 | { | ||
269 | log("PAM session setup failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); | ||
270 | do_fake_authloop(username); | ||
271 | } | ||
272 | } | 258 | } |
273 | #endif /* HAVE_LIBPAM */ | 259 | #endif /* HAVE_LIBPAM */ |
274 | 260 | ||
275 | /* Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; | 261 | /* |
276 | the effect is to reread the configuration file (and to regenerate | 262 | * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; |
277 | the server key). */ | 263 | * the effect is to reread the configuration file (and to regenerate |
278 | 264 | * the server key). | |
279 | void sighup_handler(int sig) | 265 | */ |
266 | void | ||
267 | sighup_handler(int sig) | ||
280 | { | 268 | { |
281 | received_sighup = 1; | 269 | received_sighup = 1; |
282 | signal(SIGHUP, sighup_handler); | 270 | signal(SIGHUP, sighup_handler); |
283 | } | 271 | } |
284 | 272 | ||
285 | /* Called from the main program after receiving SIGHUP. Restarts the | 273 | /* |
286 | server. */ | 274 | * Called from the main program after receiving SIGHUP. |
287 | 275 | * Restarts the server. | |
288 | void sighup_restart() | 276 | */ |
277 | void | ||
278 | sighup_restart() | ||
289 | { | 279 | { |
290 | log("Received SIGHUP; restarting."); | 280 | log("Received SIGHUP; restarting."); |
291 | close(listen_sock); | 281 | close(listen_sock); |
292 | execv(saved_argv[0], saved_argv); | 282 | execv(saved_argv[0], saved_argv); |
293 | log("RESTART FAILED: av0='%s', error: %s.", av0, strerror(errno)); | 283 | log("RESTART FAILED: av0='%s', error: %s.", av0, strerror(errno)); |
294 | exit(1); | 284 | exit(1); |
295 | } | 285 | } |
296 | 286 | ||
297 | /* Generic signal handler for terminating signals in the master daemon. | 287 | /* |
298 | These close the listen socket; not closing it seems to cause "Address | 288 | * Generic signal handler for terminating signals in the master daemon. |
299 | already in use" problems on some machines, which is inconvenient. */ | 289 | * These close the listen socket; not closing it seems to cause "Address |
300 | 290 | * already in use" problems on some machines, which is inconvenient. | |
301 | void sigterm_handler(int sig) | 291 | */ |
292 | void | ||
293 | sigterm_handler(int sig) | ||
302 | { | 294 | { |
303 | log("Received signal %d; terminating.", sig); | 295 | log("Received signal %d; terminating.", sig); |
304 | close(listen_sock); | 296 | close(listen_sock); |
305 | exit(255); | 297 | exit(255); |
306 | } | 298 | } |
307 | 299 | ||
308 | /* SIGCHLD handler. This is called whenever a child dies. This will then | 300 | /* |
309 | reap any zombies left by exited c. */ | 301 | * SIGCHLD handler. This is called whenever a child dies. This will then |
310 | 302 | * reap any zombies left by exited c. | |
311 | void main_sigchld_handler(int sig) | 303 | */ |
304 | void | ||
305 | main_sigchld_handler(int sig) | ||
312 | { | 306 | { |
313 | int save_errno = errno; | 307 | int save_errno = errno; |
314 | int status; | 308 | int status; |
315 | 309 | ||
316 | while (waitpid(-1, &status, WNOHANG) > 0) | 310 | while (waitpid(-1, &status, WNOHANG) > 0) |
317 | ; | 311 | ; |
318 | 312 | ||
319 | signal(SIGCHLD, main_sigchld_handler); | 313 | signal(SIGCHLD, main_sigchld_handler); |
320 | errno = save_errno; | 314 | errno = save_errno; |
321 | } | 315 | } |
322 | 316 | ||
323 | /* Signal handler for the alarm after the login grace period has expired. */ | 317 | /* |
324 | 318 | * Signal handler for the alarm after the login grace period has expired. | |
325 | void grace_alarm_handler(int sig) | 319 | */ |
320 | void | ||
321 | grace_alarm_handler(int sig) | ||
326 | { | 322 | { |
327 | /* Close the connection. */ | 323 | /* Close the connection. */ |
328 | packet_close(); | 324 | packet_close(); |
329 | |||
330 | /* Log error and exit. */ | ||
331 | fatal("Timeout before authentication."); | ||
332 | } | ||
333 | 325 | ||
334 | /* Signal handler for the key regeneration alarm. Note that this | 326 | /* Log error and exit. */ |
335 | alarm only occurs in the daemon waiting for connections, and it does not | 327 | fatal("Timeout before authentication for %s.", get_remote_ipaddr()); |
336 | do anything with the private key or random state before forking. Thus there | 328 | } |
337 | should be no concurrency control/asynchronous execution problems. */ | ||
338 | 329 | ||
339 | void key_regeneration_alarm(int sig) | 330 | /* |
331 | * convert ssh auth msg type into description | ||
332 | */ | ||
333 | char * | ||
334 | get_authname(int type) | ||
340 | { | 335 | { |
341 | int save_errno = errno; | 336 | switch (type) { |
342 | 337 | case SSH_CMSG_AUTH_PASSWORD: | |
343 | /* Check if we should generate a new key. */ | 338 | return "password"; |
344 | if (key_used) | 339 | case SSH_CMSG_AUTH_RSA: |
345 | { | 340 | return "rsa"; |
346 | /* This should really be done in the background. */ | 341 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
347 | log("Generating new %d bit RSA key.", options.server_key_bits); | 342 | return "rhosts-rsa"; |
348 | 343 | case SSH_CMSG_AUTH_RHOSTS: | |
349 | if (sensitive_data.private_key != NULL) | 344 | return "rhosts"; |
350 | RSA_free(sensitive_data.private_key); | 345 | #ifdef KRB4 |
351 | sensitive_data.private_key = RSA_new(); | 346 | case SSH_CMSG_AUTH_KERBEROS: |
352 | 347 | return "kerberos"; | |
353 | if (public_key != NULL) | 348 | #endif |
354 | RSA_free(public_key); | 349 | #ifdef SKEY |
355 | public_key = RSA_new(); | 350 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
356 | 351 | return "s/key"; | |
357 | rsa_generate_key(sensitive_data.private_key, public_key, | 352 | #endif |
358 | options.server_key_bits); | 353 | } |
359 | arc4random_stir(); | 354 | fatal("get_authname: unknown auth %d: internal error", type); |
360 | key_used = 0; | 355 | return NULL; |
361 | log("RSA key generation complete."); | ||
362 | } | ||
363 | |||
364 | /* Reschedule the alarm. */ | ||
365 | signal(SIGALRM, key_regeneration_alarm); | ||
366 | alarm(options.key_regeneration_time); | ||
367 | errno = save_errno; | ||
368 | } | 356 | } |
369 | 357 | ||
370 | /* Main program for the daemon. */ | 358 | /* |
359 | * Signal handler for the key regeneration alarm. Note that this | ||
360 | * alarm only occurs in the daemon waiting for connections, and it does not | ||
361 | * do anything with the private key or random state before forking. | ||
362 | * Thus there should be no concurrency control/asynchronous execution | ||
363 | * problems. | ||
364 | */ | ||
365 | void | ||
366 | key_regeneration_alarm(int sig) | ||
367 | { | ||
368 | int save_errno = errno; | ||
369 | |||
370 | /* Check if we should generate a new key. */ | ||
371 | if (key_used) { | ||
372 | /* This should really be done in the background. */ | ||
373 | log("Generating new %d bit RSA key.", options.server_key_bits); | ||
374 | |||
375 | if (sensitive_data.private_key != NULL) | ||
376 | RSA_free(sensitive_data.private_key); | ||
377 | sensitive_data.private_key = RSA_new(); | ||
378 | |||
379 | if (public_key != NULL) | ||
380 | RSA_free(public_key); | ||
381 | public_key = RSA_new(); | ||
382 | |||
383 | rsa_generate_key(sensitive_data.private_key, public_key, | ||
384 | options.server_key_bits); | ||
385 | arc4random_stir(); | ||
386 | key_used = 0; | ||
387 | log("RSA key generation complete."); | ||
388 | } | ||
389 | /* Reschedule the alarm. */ | ||
390 | signal(SIGALRM, key_regeneration_alarm); | ||
391 | alarm(options.key_regeneration_time); | ||
392 | errno = save_errno; | ||
393 | } | ||
371 | 394 | ||
395 | /* | ||
396 | * Main program for the daemon. | ||
397 | */ | ||
372 | int | 398 | int |
373 | main(int ac, char **av) | 399 | main(int ac, char **av) |
374 | { | 400 | { |
375 | extern char *optarg; | 401 | extern char *optarg; |
376 | extern int optind; | 402 | extern int optind; |
377 | int opt, aux, sock_in, sock_out, newsock, i, pid, on = 1; | 403 | int opt, aux, sock_in, sock_out, newsock, i, pid, on = 1; |
378 | int remote_major, remote_minor; | 404 | int remote_major, remote_minor; |
379 | int silentrsa = 0; | 405 | int silentrsa = 0; |
380 | struct sockaddr_in sin; | 406 | struct sockaddr_in sin; |
381 | char buf[100]; /* Must not be larger than remote_version. */ | 407 | char buf[100]; /* Must not be larger than remote_version. */ |
382 | char remote_version[100]; /* Must be at least as big as buf. */ | 408 | char remote_version[100]; /* Must be at least as big as buf. */ |
383 | int remote_port; | 409 | const char *remote_ip; |
384 | char *comment; | 410 | int remote_port; |
385 | FILE *f; | 411 | char *comment; |
386 | struct linger linger; | 412 | FILE *f; |
387 | 413 | struct linger linger; | |
388 | /* Save argv[0]. */ | 414 | |
389 | saved_argv = av; | 415 | /* Save argv[0]. */ |
390 | if (strchr(av[0], '/')) | 416 | saved_argv = av; |
391 | av0 = strrchr(av[0], '/') + 1; | 417 | if (strchr(av[0], '/')) |
392 | else | 418 | av0 = strrchr(av[0], '/') + 1; |
393 | av0 = av[0]; | 419 | else |
394 | 420 | av0 = av[0]; | |
395 | /* Initialize configuration options to their default values. */ | 421 | |
396 | initialize_server_options(&options); | 422 | /* Initialize configuration options to their default values. */ |
397 | 423 | initialize_server_options(&options); | |
398 | /* Parse command-line arguments. */ | 424 | |
399 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:diqQ")) != EOF) | 425 | /* Parse command-line arguments. */ |
400 | { | 426 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:diqQ")) != EOF) { |
401 | switch (opt) | 427 | switch (opt) { |
402 | { | 428 | case 'f': |
403 | case 'f': | 429 | config_file_name = optarg; |
404 | config_file_name = optarg; | 430 | break; |
405 | break; | 431 | case 'd': |
406 | case 'd': | 432 | debug_flag = 1; |
407 | debug_flag = 1; | 433 | options.log_level = SYSLOG_LEVEL_DEBUG; |
408 | options.log_level = SYSLOG_LEVEL_DEBUG; | 434 | break; |
409 | break; | 435 | case 'i': |
410 | case 'i': | 436 | inetd_flag = 1; |
411 | inetd_flag = 1; | 437 | break; |
412 | break; | 438 | case 'Q': |
413 | case 'Q': | 439 | silentrsa = 1; |
414 | silentrsa = 1; | 440 | break; |
415 | break; | 441 | case 'q': |
416 | case 'q': | 442 | options.log_level = SYSLOG_LEVEL_QUIET; |
417 | options.log_level = SYSLOG_LEVEL_QUIET; | 443 | break; |
418 | break; | 444 | case 'b': |
419 | case 'b': | 445 | options.server_key_bits = atoi(optarg); |
420 | options.server_key_bits = atoi(optarg); | 446 | break; |
421 | break; | 447 | case 'p': |
422 | case 'p': | 448 | options.port = atoi(optarg); |
423 | options.port = atoi(optarg); | 449 | break; |
424 | break; | 450 | case 'g': |
425 | case 'g': | 451 | options.login_grace_time = atoi(optarg); |
426 | options.login_grace_time = atoi(optarg); | 452 | break; |
427 | break; | 453 | case 'k': |
428 | case 'k': | 454 | options.key_regeneration_time = atoi(optarg); |
429 | options.key_regeneration_time = atoi(optarg); | 455 | break; |
430 | break; | 456 | case 'h': |
431 | case 'h': | 457 | options.host_key_file = optarg; |
432 | options.host_key_file = optarg; | 458 | break; |
433 | break; | 459 | case 'V': |
434 | case '?': | 460 | client_version_string = optarg; |
435 | default: | 461 | /* only makes sense with inetd_flag, i.e. no listen() */ |
436 | fprintf(stderr, "sshd version %s\n", SSH_VERSION); | 462 | inetd_flag = 1; |
437 | fprintf(stderr, "Usage: %s [options]\n", av0); | 463 | break; |
438 | fprintf(stderr, "Options:\n"); | 464 | case '?': |
439 | fprintf(stderr, " -f file Configuration file (default %s/sshd_config)\n", ETCDIR); | 465 | default: |
440 | fprintf(stderr, " -d Debugging mode\n"); | 466 | fprintf(stderr, "sshd version %s\n", SSH_VERSION); |
441 | fprintf(stderr, " -i Started from inetd\n"); | 467 | fprintf(stderr, "Usage: %s [options]\n", av0); |
442 | fprintf(stderr, " -q Quiet (no logging)\n"); | 468 | fprintf(stderr, "Options:\n"); |
443 | fprintf(stderr, " -p port Listen on the specified port (default: 22)\n"); | 469 | fprintf(stderr, " -f file Configuration file (default %s/sshd_config)\n", ETCDIR); |
444 | fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n"); | 470 | fprintf(stderr, " -d Debugging mode\n"); |
445 | fprintf(stderr, " -g seconds Grace period for authentication (default: 300)\n"); | 471 | fprintf(stderr, " -i Started from inetd\n"); |
446 | fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n"); | 472 | fprintf(stderr, " -q Quiet (no logging)\n"); |
447 | fprintf(stderr, " -h file File from which to read host key (default: %s)\n", | 473 | fprintf(stderr, " -p port Listen on the specified port (default: 22)\n"); |
448 | HOST_KEY_FILE); | 474 | fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n"); |
449 | exit(1); | 475 | fprintf(stderr, " -g seconds Grace period for authentication (default: 300)\n"); |
476 | fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n"); | ||
477 | fprintf(stderr, " -h file File from which to read host key (default: %s)\n", | ||
478 | HOST_KEY_FILE); | ||
479 | exit(1); | ||
480 | } | ||
481 | } | ||
482 | |||
483 | /* check if RSA support exists */ | ||
484 | if (rsa_alive() == 0) { | ||
485 | if (silentrsa == 0) | ||
486 | printf("sshd: no RSA support in libssl and libcrypto -- exiting. See ssl(8)\n"); | ||
487 | log("no RSA support in libssl and libcrypto -- exiting. See ssl(8)"); | ||
488 | exit(1); | ||
489 | } | ||
490 | /* Read server configuration options from the configuration file. */ | ||
491 | read_server_config(&options, config_file_name); | ||
492 | |||
493 | /* Fill in default values for those options not explicitly set. */ | ||
494 | fill_default_server_options(&options); | ||
495 | |||
496 | /* Check certain values for sanity. */ | ||
497 | if (options.server_key_bits < 512 || | ||
498 | options.server_key_bits > 32768) { | ||
499 | fprintf(stderr, "Bad server key size.\n"); | ||
500 | exit(1); | ||
501 | } | ||
502 | if (options.port < 1 || options.port > 65535) { | ||
503 | fprintf(stderr, "Bad port number.\n"); | ||
504 | exit(1); | ||
505 | } | ||
506 | /* Check that there are no remaining arguments. */ | ||
507 | if (optind < ac) { | ||
508 | fprintf(stderr, "Extra argument %s.\n", av[optind]); | ||
509 | exit(1); | ||
450 | } | 510 | } |
451 | } | 511 | /* Force logging to stderr while loading the private host key |
452 | 512 | unless started from inetd */ | |
453 | /* check if RSA support exists */ | 513 | log_init(av0, options.log_level, options.log_facility, !inetd_flag); |
454 | if (rsa_alive() == 0) { | 514 | |
455 | if (silentrsa == 0) | 515 | debug("sshd version %.100s", SSH_VERSION); |
456 | printf("sshd: no RSA support in libssl and libcrypto -- exiting. See ssl(8)\n"); | 516 | |
457 | log("no RSA support in libssl and libcrypto -- exiting. See ssl(8)"); | 517 | sensitive_data.host_key = RSA_new(); |
458 | exit(1); | 518 | errno = 0; |
459 | } | 519 | /* Load the host key. It must have empty passphrase. */ |
460 | 520 | if (!load_private_key(options.host_key_file, "", | |
461 | /* Read server configuration options from the configuration file. */ | 521 | sensitive_data.host_key, &comment)) { |
462 | read_server_config(&options, config_file_name); | 522 | error("Could not load host key: %.200s: %.100s", |
463 | 523 | options.host_key_file, strerror(errno)); | |
464 | /* Fill in default values for those options not explicitly set. */ | 524 | exit(1); |
465 | fill_default_server_options(&options); | 525 | } |
466 | 526 | xfree(comment); | |
467 | /* Check certain values for sanity. */ | 527 | |
468 | if (options.server_key_bits < 512 || | 528 | /* Initialize the log (it is reinitialized below in case we |
469 | options.server_key_bits > 32768) | 529 | forked). */ |
470 | { | 530 | if (debug_flag && !inetd_flag) |
471 | fprintf(stderr, "Bad server key size.\n"); | 531 | log_stderr = 1; |
472 | exit(1); | 532 | log_init(av0, options.log_level, options.log_facility, log_stderr); |
473 | } | 533 | |
474 | if (options.port < 1 || options.port > 65535) | 534 | /* If not in debugging mode, and not started from inetd, |
475 | { | 535 | disconnect from the controlling terminal, and fork. The |
476 | fprintf(stderr, "Bad port number.\n"); | 536 | original process exits. */ |
477 | exit(1); | 537 | if (!debug_flag && !inetd_flag) { |
478 | } | ||
479 | |||
480 | /* Check that there are no remaining arguments. */ | ||
481 | if (optind < ac) | ||
482 | { | ||
483 | fprintf(stderr, "Extra argument %s.\n", av[optind]); | ||
484 | exit(1); | ||
485 | } | ||
486 | |||
487 | /* Force logging to stderr while loading the private host key | ||
488 | unless started from inetd */ | ||
489 | log_init(av0, options.log_level, options.log_facility, !inetd_flag); | ||
490 | |||
491 | debug("sshd version %.100s", SSH_VERSION); | ||
492 | |||
493 | sensitive_data.host_key = RSA_new(); | ||
494 | errno = 0; | ||
495 | /* Load the host key. It must have empty passphrase. */ | ||
496 | if (!load_private_key(options.host_key_file, "", | ||
497 | sensitive_data.host_key, &comment)) | ||
498 | { | ||
499 | error("Could not load host key: %.200s: %.100s", | ||
500 | options.host_key_file, strerror(errno)); | ||
501 | exit(1); | ||
502 | } | ||
503 | xfree(comment); | ||
504 | |||
505 | /* Initialize the log (it is reinitialized below in case we forked). */ | ||
506 | if (debug_flag && !inetd_flag) | ||
507 | log_stderr = 1; | ||
508 | log_init(av0, options.log_level, options.log_facility, log_stderr); | ||
509 | |||
510 | /* If not in debugging mode, and not started from inetd, disconnect from | ||
511 | the controlling terminal, and fork. The original process exits. */ | ||
512 | if (!debug_flag && !inetd_flag) | ||
513 | { | ||
514 | #ifdef TIOCNOTTY | 538 | #ifdef TIOCNOTTY |
515 | int fd; | 539 | int fd; |
516 | #endif /* TIOCNOTTY */ | 540 | #endif /* TIOCNOTTY */ |
517 | if (daemon(0, 0) < 0) | 541 | if (daemon(0, 0) < 0) |
518 | fatal("daemon() failed: %.200s", strerror(errno)); | 542 | fatal("daemon() failed: %.200s", strerror(errno)); |
519 | 543 | ||
520 | /* Disconnect from the controlling tty. */ | 544 | /* Disconnect from the controlling tty. */ |
521 | #ifdef TIOCNOTTY | 545 | #ifdef TIOCNOTTY |
522 | fd = open("/dev/tty", O_RDWR|O_NOCTTY); | 546 | fd = open("/dev/tty", O_RDWR | O_NOCTTY); |
523 | if (fd >= 0) | 547 | if (fd >= 0) { |
524 | { | 548 | (void) ioctl(fd, TIOCNOTTY, NULL); |
525 | (void)ioctl(fd, TIOCNOTTY, NULL); | 549 | close(fd); |
526 | close(fd); | 550 | } |
527 | } | ||
528 | #endif /* TIOCNOTTY */ | 551 | #endif /* TIOCNOTTY */ |
529 | } | ||
530 | |||
531 | /* Reinitialize the log (because of the fork above). */ | ||
532 | log_init(av0, options.log_level, options.log_facility, log_stderr); | ||
533 | |||
534 | /* Check that server and host key lengths differ sufficiently. This is | ||
535 | necessary to make double encryption work with rsaref. Oh, I hate | ||
536 | software patents. I dont know if this can go? Niels */ | ||
537 | if (options.server_key_bits > | ||
538 | BN_num_bits(sensitive_data.host_key->n) - SSH_KEY_BITS_RESERVED && | ||
539 | options.server_key_bits < | ||
540 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) | ||
541 | { | ||
542 | options.server_key_bits = | ||
543 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED; | ||
544 | debug("Forcing server key to %d bits to make it differ from host key.", | ||
545 | options.server_key_bits); | ||
546 | } | ||
547 | |||
548 | /* Do not display messages to stdout in RSA code. */ | ||
549 | rsa_set_verbose(0); | ||
550 | |||
551 | /* Initialize the random number generator. */ | ||
552 | arc4random_stir(); | ||
553 | |||
554 | /* Chdir to the root directory so that the current disk can be unmounted | ||
555 | if desired. */ | ||
556 | chdir("/"); | ||
557 | |||
558 | /* Close connection cleanly after attack. */ | ||
559 | cipher_attack_detected = packet_disconnect; | ||
560 | |||
561 | /* Start listening for a socket, unless started from inetd. */ | ||
562 | if (inetd_flag) | ||
563 | { | ||
564 | int s1, s2; | ||
565 | s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */ | ||
566 | s2 = dup(s1); | ||
567 | sock_in = dup(0); | ||
568 | sock_out = dup(1); | ||
569 | /* We intentionally do not close the descriptors 0, 1, and 2 as our | ||
570 | code for setting the descriptors won\'t work if ttyfd happens to | ||
571 | be one of those. */ | ||
572 | debug("inetd sockets after dupping: %d, %d", sock_in, sock_out); | ||
573 | |||
574 | public_key = RSA_new(); | ||
575 | sensitive_data.private_key = RSA_new(); | ||
576 | /* Generate an rsa key. */ | ||
577 | log("Generating %d bit RSA key.", options.server_key_bits); | ||
578 | rsa_generate_key(sensitive_data.private_key, public_key, | ||
579 | options.server_key_bits); | ||
580 | arc4random_stir(); | ||
581 | log("RSA key generation complete."); | ||
582 | } | ||
583 | else | ||
584 | { | ||
585 | /* Create socket for listening. */ | ||
586 | listen_sock = socket(AF_INET, SOCK_STREAM, 0); | ||
587 | if (listen_sock < 0) | ||
588 | fatal("socket: %.100s", strerror(errno)); | ||
589 | |||
590 | /* Set socket options. We try to make the port reusable and have it | ||
591 | close as fast as possible without waiting in unnecessary wait states | ||
592 | on close. */ | ||
593 | setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, | ||
594 | sizeof(on)); | ||
595 | linger.l_onoff = 1; | ||
596 | linger.l_linger = 5; | ||
597 | setsockopt(listen_sock, SOL_SOCKET, SO_LINGER, (void *)&linger, | ||
598 | sizeof(linger)); | ||
599 | |||
600 | /* Initialize the socket address. */ | ||
601 | memset(&sin, 0, sizeof(sin)); | ||
602 | sin.sin_family = AF_INET; | ||
603 | sin.sin_addr = options.listen_addr; | ||
604 | sin.sin_port = htons(options.port); | ||
605 | |||
606 | /* Bind the socket to the desired port. */ | ||
607 | if (bind(listen_sock, (struct sockaddr *)&sin, sizeof(sin)) < 0) | ||
608 | { | ||
609 | error("bind: %.100s", strerror(errno)); | ||
610 | shutdown(listen_sock, SHUT_RDWR); | ||
611 | close(listen_sock); | ||
612 | fatal("Bind to port %d failed.", options.port); | ||
613 | } | 552 | } |
614 | 553 | /* Reinitialize the log (because of the fork above). */ | |
615 | if (!debug_flag) | 554 | log_init(av0, options.log_level, options.log_facility, log_stderr); |
616 | { | 555 | |
617 | /* Record our pid in /etc/sshd_pid to make it easier to kill the | 556 | /* Check that server and host key lengths differ sufficiently. |
618 | correct sshd. We don\'t want to do this before the bind above | 557 | This is necessary to make double encryption work with rsaref. |
619 | because the bind will fail if there already is a daemon, and this | 558 | Oh, I hate software patents. I dont know if this can go? Niels */ |
620 | will overwrite any old pid in the file. */ | 559 | if (options.server_key_bits > |
621 | f = fopen(SSH_DAEMON_PID_FILE, "w"); | 560 | BN_num_bits(sensitive_data.host_key->n) - SSH_KEY_BITS_RESERVED && |
622 | if (f) | 561 | options.server_key_bits < |
623 | { | 562 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) { |
624 | fprintf(f, "%u\n", (unsigned int)getpid()); | 563 | options.server_key_bits = |
625 | fclose(f); | 564 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED; |
626 | } | 565 | debug("Forcing server key to %d bits to make it differ from host key.", |
566 | options.server_key_bits); | ||
627 | } | 567 | } |
628 | 568 | /* Do not display messages to stdout in RSA code. */ | |
629 | /* Start listening on the port. */ | 569 | rsa_set_verbose(0); |
630 | log("Server listening on port %d.", options.port); | 570 | |
631 | if (listen(listen_sock, 5) < 0) | 571 | /* Initialize the random number generator. */ |
632 | fatal("listen: %.100s", strerror(errno)); | 572 | arc4random_stir(); |
633 | 573 | ||
634 | public_key = RSA_new(); | 574 | /* Chdir to the root directory so that the current disk can be |
635 | sensitive_data.private_key = RSA_new(); | 575 | unmounted if desired. */ |
636 | /* Generate an rsa key. */ | 576 | chdir("/"); |
637 | log("Generating %d bit RSA key.", options.server_key_bits); | 577 | |
638 | rsa_generate_key(sensitive_data.private_key, public_key, | 578 | /* Close connection cleanly after attack. */ |
639 | options.server_key_bits); | 579 | cipher_attack_detected = packet_disconnect; |
640 | arc4random_stir(); | 580 | |
641 | log("RSA key generation complete."); | 581 | /* Start listening for a socket, unless started from inetd. */ |
642 | 582 | if (inetd_flag) { | |
643 | /* Schedule server key regeneration alarm. */ | 583 | int s1, s2; |
644 | signal(SIGALRM, key_regeneration_alarm); | 584 | s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */ |
645 | alarm(options.key_regeneration_time); | 585 | s2 = dup(s1); |
646 | 586 | sock_in = dup(0); | |
647 | /* Arrange to restart on SIGHUP. The handler needs listen_sock. */ | 587 | sock_out = dup(1); |
648 | signal(SIGHUP, sighup_handler); | 588 | /* We intentionally do not close the descriptors 0, 1, and 2 |
649 | signal(SIGTERM, sigterm_handler); | 589 | as our code for setting the descriptors won\'t work |
650 | signal(SIGQUIT, sigterm_handler); | 590 | if ttyfd happens to be one of those. */ |
651 | 591 | debug("inetd sockets after dupping: %d, %d", sock_in, sock_out); | |
652 | /* Arrange SIGCHLD to be caught. */ | 592 | |
653 | signal(SIGCHLD, main_sigchld_handler); | 593 | public_key = RSA_new(); |
654 | 594 | sensitive_data.private_key = RSA_new(); | |
655 | /* Stay listening for connections until the system crashes or the | 595 | |
656 | daemon is killed with a signal. */ | 596 | log("Generating %d bit RSA key.", options.server_key_bits); |
657 | for (;;) | 597 | rsa_generate_key(sensitive_data.private_key, public_key, |
658 | { | 598 | options.server_key_bits); |
659 | if (received_sighup) | 599 | arc4random_stir(); |
660 | sighup_restart(); | 600 | log("RSA key generation complete."); |
661 | /* Wait in accept until there is a connection. */ | 601 | } else { |
662 | aux = sizeof(sin); | 602 | /* Create socket for listening. */ |
663 | newsock = accept(listen_sock, (struct sockaddr *)&sin, &aux); | 603 | listen_sock = socket(AF_INET, SOCK_STREAM, 0); |
664 | if (received_sighup) | 604 | if (listen_sock < 0) |
665 | sighup_restart(); | 605 | fatal("socket: %.100s", strerror(errno)); |
666 | if (newsock < 0) | 606 | |
667 | { | 607 | /* Set socket options. We try to make the port reusable |
668 | if (errno == EINTR) | 608 | and have it close as fast as possible without waiting |
669 | continue; | 609 | in unnecessary wait states on close. */ |
670 | error("accept: %.100s", strerror(errno)); | 610 | setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, (void *) &on, |
671 | continue; | 611 | sizeof(on)); |
672 | } | 612 | linger.l_onoff = 1; |
673 | 613 | linger.l_linger = 5; | |
674 | /* Got connection. Fork a child to handle it, unless we are in | 614 | setsockopt(listen_sock, SOL_SOCKET, SO_LINGER, (void *) &linger, |
675 | debugging mode. */ | 615 | sizeof(linger)); |
676 | if (debug_flag) | 616 | |
677 | { | 617 | /* Initialize the socket address. */ |
678 | /* In debugging mode. Close the listening socket, and start | 618 | memset(&sin, 0, sizeof(sin)); |
679 | processing the connection without forking. */ | 619 | sin.sin_family = AF_INET; |
680 | debug("Server will not fork when running in debugging mode."); | 620 | sin.sin_addr = options.listen_addr; |
681 | close(listen_sock); | 621 | sin.sin_port = htons(options.port); |
682 | sock_in = newsock; | 622 | |
683 | sock_out = newsock; | 623 | /* Bind the socket to the desired port. */ |
684 | pid = getpid(); | 624 | if (bind(listen_sock, (struct sockaddr *) & sin, sizeof(sin)) < 0) { |
685 | break; | 625 | error("bind: %.100s", strerror(errno)); |
686 | } | 626 | shutdown(listen_sock, SHUT_RDWR); |
687 | else | 627 | close(listen_sock); |
688 | { | 628 | fatal("Bind to port %d failed.", options.port); |
689 | /* Normal production daemon. Fork, and have the child process | 629 | } |
690 | the connection. The parent continues listening. */ | 630 | if (!debug_flag) { |
691 | if ((pid = fork()) == 0) | 631 | /* Record our pid in /etc/sshd_pid to make it |
692 | { | 632 | easier to kill the correct sshd. We don\'t |
693 | /* Child. Close the listening socket, and start using | 633 | want to do this before the bind above because |
694 | the accepted socket. Reinitialize logging (since our | 634 | the bind will fail if there already is a |
695 | pid has changed). We break out of the loop to handle | 635 | daemon, and this will overwrite any old pid in |
696 | the connection. */ | 636 | the file. */ |
697 | close(listen_sock); | 637 | f = fopen(SSH_DAEMON_PID_FILE, "w"); |
698 | sock_in = newsock; | 638 | if (f) { |
699 | sock_out = newsock; | 639 | fprintf(f, "%u\n", (unsigned int) getpid()); |
700 | log_init(av0, options.log_level, options.log_facility, log_stderr); | 640 | fclose(f); |
701 | break; | 641 | } |
702 | } | 642 | } |
703 | } | ||
704 | 643 | ||
705 | /* Parent. Stay in the loop. */ | 644 | log("Server listening on port %d.", options.port); |
706 | if (pid < 0) | 645 | if (listen(listen_sock, 5) < 0) |
707 | error("fork: %.100s", strerror(errno)); | 646 | fatal("listen: %.100s", strerror(errno)); |
708 | else | 647 | |
709 | debug("Forked child %d.", pid); | 648 | public_key = RSA_new(); |
649 | sensitive_data.private_key = RSA_new(); | ||
650 | |||
651 | log("Generating %d bit RSA key.", options.server_key_bits); | ||
652 | rsa_generate_key(sensitive_data.private_key, public_key, | ||
653 | options.server_key_bits); | ||
654 | arc4random_stir(); | ||
655 | log("RSA key generation complete."); | ||
656 | |||
657 | /* Schedule server key regeneration alarm. */ | ||
658 | signal(SIGALRM, key_regeneration_alarm); | ||
659 | alarm(options.key_regeneration_time); | ||
660 | |||
661 | /* Arrange to restart on SIGHUP. The handler needs listen_sock. */ | ||
662 | signal(SIGHUP, sighup_handler); | ||
663 | signal(SIGTERM, sigterm_handler); | ||
664 | signal(SIGQUIT, sigterm_handler); | ||
665 | |||
666 | /* Arrange SIGCHLD to be caught. */ | ||
667 | signal(SIGCHLD, main_sigchld_handler); | ||
668 | |||
669 | /* Stay listening for connections until the system crashes | ||
670 | or the daemon is killed with a signal. */ | ||
671 | for (;;) { | ||
672 | if (received_sighup) | ||
673 | sighup_restart(); | ||
674 | /* Wait in accept until there is a connection. */ | ||
675 | aux = sizeof(sin); | ||
676 | newsock = accept(listen_sock, (struct sockaddr *) & sin, &aux); | ||
677 | if (received_sighup) | ||
678 | sighup_restart(); | ||
679 | if (newsock < 0) { | ||
680 | if (errno == EINTR) | ||
681 | continue; | ||
682 | error("accept: %.100s", strerror(errno)); | ||
683 | continue; | ||
684 | } | ||
685 | /* Got connection. Fork a child to handle it, | ||
686 | unless we are in debugging mode. */ | ||
687 | if (debug_flag) { | ||
688 | /* In debugging mode. Close the listening | ||
689 | socket, and start processing the | ||
690 | connection without forking. */ | ||
691 | debug("Server will not fork when running in debugging mode."); | ||
692 | close(listen_sock); | ||
693 | sock_in = newsock; | ||
694 | sock_out = newsock; | ||
695 | pid = getpid(); | ||
696 | break; | ||
697 | } else { | ||
698 | /* Normal production daemon. Fork, and | ||
699 | have the child process the connection. | ||
700 | The parent continues listening. */ | ||
701 | if ((pid = fork()) == 0) { | ||
702 | /* Child. Close the listening | ||
703 | socket, and start using the | ||
704 | accepted socket. Reinitialize | ||
705 | logging (since our pid has | ||
706 | changed). We break out of the | ||
707 | loop to handle the connection. */ | ||
708 | close(listen_sock); | ||
709 | sock_in = newsock; | ||
710 | sock_out = newsock; | ||
711 | log_init(av0, options.log_level, options.log_facility, log_stderr); | ||
712 | break; | ||
713 | } | ||
714 | } | ||
715 | |||
716 | /* Parent. Stay in the loop. */ | ||
717 | if (pid < 0) | ||
718 | error("fork: %.100s", strerror(errno)); | ||
719 | else | ||
720 | debug("Forked child %d.", pid); | ||
721 | |||
722 | /* Mark that the key has been used (it was "given" to the child). */ | ||
723 | key_used = 1; | ||
724 | |||
725 | arc4random_stir(); | ||
726 | |||
727 | /* Close the new socket (the child is now taking care of it). */ | ||
728 | close(newsock); | ||
729 | } | ||
730 | } | ||
710 | 731 | ||
711 | /* Mark that the key has been used (it was "given" to the child). */ | 732 | /* This is the child processing a new connection. */ |
712 | key_used = 1; | 733 | |
734 | /* Disable the key regeneration alarm. We will not regenerate the | ||
735 | key since we are no longer in a position to give it to anyone. | ||
736 | We will not restart on SIGHUP since it no longer makes sense. */ | ||
737 | alarm(0); | ||
738 | signal(SIGALRM, SIG_DFL); | ||
739 | signal(SIGHUP, SIG_DFL); | ||
740 | signal(SIGTERM, SIG_DFL); | ||
741 | signal(SIGQUIT, SIG_DFL); | ||
742 | signal(SIGCHLD, SIG_DFL); | ||
743 | |||
744 | /* Set socket options for the connection. We want the socket to | ||
745 | close as fast as possible without waiting for anything. If the | ||
746 | connection is not a socket, these will do nothing. */ | ||
747 | /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, | ||
748 | sizeof(on)); */ | ||
749 | linger.l_onoff = 1; | ||
750 | linger.l_linger = 5; | ||
751 | setsockopt(sock_in, SOL_SOCKET, SO_LINGER, (void *) &linger, sizeof(linger)); | ||
752 | |||
753 | /* Register our connection. This turns encryption off because we | ||
754 | do not have a key. */ | ||
755 | packet_set_connection(sock_in, sock_out); | ||
756 | |||
757 | remote_port = get_remote_port(); | ||
758 | remote_ip = get_remote_ipaddr(); | ||
759 | |||
760 | /* Check whether logins are denied from this host. */ | ||
761 | #ifdef LIBWRAP | ||
762 | { | ||
763 | struct request_info req; | ||
713 | 764 | ||
714 | arc4random_stir(); | 765 | request_init(&req, RQ_DAEMON, av0, RQ_FILE, sock_in, NULL); |
766 | fromhost(&req); | ||
715 | 767 | ||
716 | /* Close the new socket (the child is now taking care of it). */ | 768 | if (!hosts_access(&req)) { |
717 | close(newsock); | 769 | close(sock_in); |
770 | close(sock_out); | ||
771 | refuse(&req); | ||
772 | } | ||
773 | verbose("Connection from %.500s port %d", eval_client(&req), remote_port); | ||
718 | } | 774 | } |
719 | } | ||
720 | |||
721 | /* This is the child processing a new connection. */ | ||
722 | |||
723 | /* Disable the key regeneration alarm. We will not regenerate the key | ||
724 | since we are no longer in a position to give it to anyone. We will | ||
725 | not restart on SIGHUP since it no longer makes sense. */ | ||
726 | alarm(0); | ||
727 | signal(SIGALRM, SIG_DFL); | ||
728 | signal(SIGHUP, SIG_DFL); | ||
729 | signal(SIGTERM, SIG_DFL); | ||
730 | signal(SIGQUIT, SIG_DFL); | ||
731 | signal(SIGCHLD, SIG_DFL); | ||
732 | |||
733 | /* Set socket options for the connection. We want the socket to close | ||
734 | as fast as possible without waiting for anything. If the connection | ||
735 | is not a socket, these will do nothing. */ | ||
736 | /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */ | ||
737 | linger.l_onoff = 1; | ||
738 | linger.l_linger = 5; | ||
739 | setsockopt(sock_in, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); | ||
740 | |||
741 | /* Register our connection. This turns encryption off because we do not | ||
742 | have a key. */ | ||
743 | packet_set_connection(sock_in, sock_out); | ||
744 | |||
745 | remote_port = get_remote_port(); | ||
746 | |||
747 | /* Check whether logins are denied from this host. */ | ||
748 | #ifdef LIBWRAP | ||
749 | { | ||
750 | struct request_info req; | ||
751 | |||
752 | request_init(&req, RQ_DAEMON, av0, RQ_FILE, sock_in, NULL); | ||
753 | fromhost(&req); | ||
754 | |||
755 | if (!hosts_access(&req)) { | ||
756 | close(sock_in); | ||
757 | close(sock_out); | ||
758 | refuse(&req); | ||
759 | } | ||
760 | log("Connection from %.500s port %d", eval_client(&req), remote_port); | ||
761 | } | ||
762 | #else | 775 | #else |
763 | /* Log the connection. */ | 776 | /* Log the connection. */ |
764 | log("Connection from %.100s port %d", get_remote_ipaddr(), remote_port); | 777 | verbose("Connection from %.500s port %d", remote_ip, remote_port); |
765 | #endif /* LIBWRAP */ | 778 | #endif /* LIBWRAP */ |
766 | 779 | ||
767 | /* We don\'t want to listen forever unless the other side successfully | 780 | /* We don\'t want to listen forever unless the other side |
768 | authenticates itself. So we set up an alarm which is cleared after | 781 | successfully authenticates itself. So we set up an alarm which |
769 | successful authentication. A limit of zero indicates no limit. | 782 | is cleared after successful authentication. A limit of zero |
770 | Note that we don\'t set the alarm in debugging mode; it is just annoying | 783 | indicates no limit. Note that we don\'t set the alarm in |
771 | to have the server exit just when you are about to discover the bug. */ | 784 | debugging mode; it is just annoying to have the server exit |
772 | signal(SIGALRM, grace_alarm_handler); | 785 | just when you are about to discover the bug. */ |
773 | if (!debug_flag) | 786 | signal(SIGALRM, grace_alarm_handler); |
774 | alarm(options.login_grace_time); | 787 | if (!debug_flag) |
775 | 788 | alarm(options.login_grace_time); | |
776 | /* Send our protocol version identification. */ | 789 | |
777 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | 790 | if (client_version_string != NULL) { |
778 | PROTOCOL_MAJOR, PROTOCOL_MINOR, SSH_VERSION); | 791 | /* we are exec'ed by sshd2, so skip exchange of protocol version */ |
779 | if (write(sock_out, buf, strlen(buf)) != strlen(buf)) | 792 | strlcpy(buf, client_version_string, sizeof(buf)); |
780 | fatal("Could not write ident string."); | 793 | } else { |
781 | 794 | /* Send our protocol version identification. */ | |
782 | /* Read other side\'s version identification. */ | 795 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", |
783 | for (i = 0; i < sizeof(buf) - 1; i++) | 796 | PROTOCOL_MAJOR, PROTOCOL_MINOR, SSH_VERSION); |
784 | { | 797 | if (write(sock_out, buf, strlen(buf)) != strlen(buf)) |
785 | if (read(sock_in, &buf[i], 1) != 1) | 798 | fatal("Could not write ident string to %s.", get_remote_ipaddr()); |
786 | fatal("Did not receive ident string."); | 799 | |
787 | if (buf[i] == '\r') | 800 | /* Read other side\'s version identification. */ |
788 | { | 801 | for (i = 0; i < sizeof(buf) - 1; i++) { |
789 | buf[i] = '\n'; | 802 | if (read(sock_in, &buf[i], 1) != 1) |
790 | buf[i + 1] = 0; | 803 | fatal("Did not receive ident string from %s.", get_remote_ipaddr()); |
791 | break; | 804 | if (buf[i] == '\r') { |
805 | buf[i] = '\n'; | ||
806 | buf[i + 1] = 0; | ||
807 | break; | ||
808 | } | ||
809 | if (buf[i] == '\n') { | ||
810 | /* buf[i] == '\n' */ | ||
811 | buf[i + 1] = 0; | ||
812 | break; | ||
813 | } | ||
814 | } | ||
815 | buf[sizeof(buf) - 1] = 0; | ||
792 | } | 816 | } |
793 | if (buf[i] == '\n') | 817 | |
794 | { | 818 | /* Check that the versions match. In future this might accept |
795 | /* buf[i] == '\n' */ | 819 | several versions and set appropriate flags to handle them. */ |
796 | buf[i + 1] = 0; | 820 | if (sscanf(buf, "SSH-%d.%d-%[^\n]\n", &remote_major, &remote_minor, |
797 | break; | 821 | remote_version) != 3) { |
822 | const char *s = "Protocol mismatch.\n"; | ||
823 | (void) write(sock_out, s, strlen(s)); | ||
824 | close(sock_in); | ||
825 | close(sock_out); | ||
826 | fatal("Bad protocol version identification '%.100s' from %s", | ||
827 | buf, get_remote_ipaddr()); | ||
828 | } | ||
829 | debug("Client protocol version %d.%d; client software version %.100s", | ||
830 | remote_major, remote_minor, remote_version); | ||
831 | if (remote_major != PROTOCOL_MAJOR) { | ||
832 | const char *s = "Protocol major versions differ.\n"; | ||
833 | (void) write(sock_out, s, strlen(s)); | ||
834 | close(sock_in); | ||
835 | close(sock_out); | ||
836 | fatal("Protocol major versions differ for %s: %d vs. %d", | ||
837 | get_remote_ipaddr(), | ||
838 | PROTOCOL_MAJOR, remote_major); | ||
798 | } | 839 | } |
799 | } | 840 | /* Check that the client has sufficiently high software version. */ |
800 | buf[sizeof(buf) - 1] = 0; | 841 | if (remote_major == 1 && remote_minor < 3) |
801 | 842 | packet_disconnect("Your ssh version is too old and is no longer supported. Please install a newer version."); | |
802 | /* Check that the versions match. In future this might accept several | 843 | |
803 | versions and set appropriate flags to handle them. */ | 844 | if (remote_major == 1 && remote_minor == 3) { |
804 | if (sscanf(buf, "SSH-%d.%d-%[^\n]\n", &remote_major, &remote_minor, | 845 | enable_compat13(); |
805 | remote_version) != 3) | 846 | if (strcmp(remote_version, "OpenSSH-1.1") != 0) { |
806 | { | 847 | debug("Agent forwarding disabled, remote version is not compatible."); |
807 | const char *s = "Protocol mismatch.\n"; | 848 | no_agent_forwarding_flag = 1; |
808 | (void) write(sock_out, s, strlen(s)); | 849 | } |
809 | close(sock_in); | 850 | } |
810 | close(sock_out); | 851 | /* Check that the connection comes from a privileged port. Rhosts- |
811 | fatal("Bad protocol version identification: %.100s", buf); | 852 | and Rhosts-RSA-Authentication only make sense from priviledged |
812 | } | 853 | programs. Of course, if the intruder has root access on his |
813 | debug("Client protocol version %d.%d; client software version %.100s", | 854 | local machine, he can connect from any port. So do not use |
814 | remote_major, remote_minor, remote_version); | 855 | these authentication methods from machines that you do not trust. */ |
815 | if (remote_major != PROTOCOL_MAJOR) | 856 | if (remote_port >= IPPORT_RESERVED || |
816 | { | 857 | remote_port < IPPORT_RESERVED / 2) { |
817 | const char *s = "Protocol major versions differ.\n"; | 858 | options.rhosts_authentication = 0; |
818 | (void) write(sock_out, s, strlen(s)); | 859 | options.rhosts_rsa_authentication = 0; |
819 | close(sock_in); | 860 | } |
820 | close(sock_out); | 861 | packet_set_nonblocking(); |
821 | fatal("Protocol major versions differ: %d vs. %d", | 862 | |
822 | PROTOCOL_MAJOR, remote_major); | 863 | /* Handle the connection. */ |
823 | } | 864 | do_connection(); |
824 | |||
825 | /* Check that the client has sufficiently high software version. */ | ||
826 | if (remote_major == 1 && remote_minor < 3) | ||
827 | packet_disconnect("Your ssh version is too old and is no longer supported. Please install a newer version."); | ||
828 | |||
829 | if (remote_major == 1 && remote_minor == 3) { | ||
830 | enable_compat13(); | ||
831 | if (strcmp(remote_version, "OpenSSH-1.1") != 0) { | ||
832 | debug("Agent forwarding disabled, remote version is not compatible."); | ||
833 | no_agent_forwarding_flag = 1; | ||
834 | } | ||
835 | } | ||
836 | |||
837 | /* Check that the connection comes from a privileged port. | ||
838 | Rhosts- and Rhosts-RSA-Authentication only make sense | ||
839 | from priviledged programs. | ||
840 | Of course, if the intruder has root access on his local machine, | ||
841 | he can connect from any port. So do not use these authentication | ||
842 | methods from machines that you do not trust. */ | ||
843 | if (remote_port >= IPPORT_RESERVED || | ||
844 | remote_port < IPPORT_RESERVED / 2) | ||
845 | { | ||
846 | options.rhosts_authentication = 0; | ||
847 | options.rhosts_rsa_authentication = 0; | ||
848 | } | ||
849 | |||
850 | packet_set_nonblocking(); | ||
851 | |||
852 | /* Handle the connection. */ | ||
853 | do_connection(); | ||
854 | 865 | ||
855 | #ifdef KRB4 | 866 | #ifdef KRB4 |
856 | /* Cleanup user's ticket cache file. */ | 867 | /* Cleanup user's ticket cache file. */ |
857 | if (options.kerberos_ticket_cleanup) | 868 | if (options.kerberos_ticket_cleanup) |
858 | (void) dest_tkt(); | 869 | (void) dest_tkt(); |
859 | #endif /* KRB4 */ | 870 | #endif /* KRB4 */ |
860 | 871 | ||
861 | /* Cleanup user's local Xauthority file. */ | 872 | /* Cleanup user's local Xauthority file. */ |
862 | if (xauthfile) unlink(xauthfile); | 873 | if (xauthfile) |
874 | unlink(xauthfile); | ||
863 | 875 | ||
864 | /* The connection has been terminated. */ | 876 | /* The connection has been terminated. */ |
865 | log("Closing connection to %.100s", inet_ntoa(sin.sin_addr)); | 877 | verbose("Closing connection to %.100s", remote_ip); |
866 | 878 | ||
867 | #ifdef HAVE_LIBPAM | 879 | #ifdef HAVE_LIBPAM |
868 | { | 880 | { |
869 | int retval; | 881 | int retval; |
870 | |||
871 | if (pamh != NULL) | ||
872 | { | ||
873 | debug("Closing PAM session."); | ||
874 | retval = pam_close_session((pam_handle_t *)pamh, 0); | ||
875 | |||
876 | debug("Terminating PAM library."); | ||
877 | if (pam_end((pam_handle_t *)pamh, retval) != PAM_SUCCESS) | ||
878 | log("Cannot release PAM authentication."); | ||
879 | |||
880 | fatal_remove_cleanup(&pam_cleanup_proc, NULL); | ||
881 | } | ||
882 | } | ||
883 | #endif /* HAVE_LIBPAM */ | ||
884 | 882 | ||
885 | packet_close(); | 883 | if (pamh != NULL) { |
884 | debug("Closing PAM session."); | ||
885 | retval = pam_close_session((pam_handle_t *)pamh, 0); | ||
886 | 886 | ||
887 | exit(0); | 887 | debug("Terminating PAM library."); |
888 | } | 888 | if (pam_end((pam_handle_t *)pamh, retval) != PAM_SUCCESS) |
889 | log("Cannot release PAM authentication."); | ||
890 | |||
891 | fatal_remove_cleanup(&pam_cleanup_proc, NULL); | ||
892 | } | ||
893 | } | ||
894 | #endif /* HAVE_LIBPAM */ | ||
889 | 895 | ||
890 | /* Process an incoming connection. Protocol version identifiers have already | 896 | packet_close(); |
891 | been exchanged. This sends server key and performs the key exchange. | 897 | exit(0); |
892 | Server and host keys will no longer be needed after this functions. */ | 898 | } |
893 | 899 | ||
900 | /* | ||
901 | * Process an incoming connection. Protocol version identifiers have already | ||
902 | * been exchanged. This sends server key and performs the key exchange. | ||
903 | * Server and host keys will no longer be needed after this functions. | ||
904 | */ | ||
894 | void | 905 | void |
895 | do_connection() | 906 | do_connection() |
896 | { | 907 | { |
897 | int i, len; | 908 | int i, len; |
898 | BIGNUM *session_key_int; | 909 | BIGNUM *session_key_int; |
899 | unsigned char session_key[SSH_SESSION_KEY_LENGTH]; | 910 | unsigned char session_key[SSH_SESSION_KEY_LENGTH]; |
900 | unsigned char check_bytes[8]; | 911 | unsigned char check_bytes[8]; |
901 | char *user; | 912 | char *user; |
902 | unsigned int cipher_type, auth_mask, protocol_flags; | 913 | unsigned int cipher_type, auth_mask, protocol_flags; |
903 | int plen, slen; | 914 | int plen, slen; |
904 | u_int32_t rand = 0; | 915 | u_int32_t rand = 0; |
905 | 916 | ||
906 | /* Generate check bytes that the client must send back in the user packet | 917 | /* Generate check bytes that the client must send back in the user |
907 | in order for it to be accepted; this is used to defy ip spoofing | 918 | packet in order for it to be accepted; this is used to defy ip |
908 | attacks. Note that this only works against somebody doing IP spoofing | 919 | spoofing attacks. Note that this only works against somebody |
909 | from a remote machine; any machine on the local network can still see | 920 | doing IP spoofing from a remote machine; any machine on the |
910 | outgoing packets and catch the random cookie. This only affects | 921 | local network can still see outgoing packets and catch the |
911 | rhosts authentication, and this is one of the reasons why it is | 922 | random cookie. This only affects rhosts authentication, and |
912 | inherently insecure. */ | 923 | this is one of the reasons why it is inherently insecure. */ |
913 | for (i = 0; i < 8; i++) { | 924 | for (i = 0; i < 8; i++) { |
914 | if (i % 4 == 0) | 925 | if (i % 4 == 0) |
915 | rand = arc4random(); | 926 | rand = arc4random(); |
916 | check_bytes[i] = rand & 0xff; | 927 | check_bytes[i] = rand & 0xff; |
917 | rand >>= 8; | 928 | rand >>= 8; |
918 | } | 929 | } |
919 | 930 | ||
920 | /* Send our public key. We include in the packet 64 bits of random | 931 | /* Send our public key. We include in the packet 64 bits of |
921 | data that must be matched in the reply in order to prevent IP spoofing. */ | 932 | random data that must be matched in the reply in order to |
922 | packet_start(SSH_SMSG_PUBLIC_KEY); | 933 | prevent IP spoofing. */ |
923 | for (i = 0; i < 8; i++) | 934 | packet_start(SSH_SMSG_PUBLIC_KEY); |
924 | packet_put_char(check_bytes[i]); | 935 | for (i = 0; i < 8; i++) |
925 | 936 | packet_put_char(check_bytes[i]); | |
926 | /* Store our public server RSA key. */ | 937 | |
927 | packet_put_int(BN_num_bits(public_key->n)); | 938 | /* Store our public server RSA key. */ |
928 | packet_put_bignum(public_key->e); | 939 | packet_put_int(BN_num_bits(public_key->n)); |
929 | packet_put_bignum(public_key->n); | 940 | packet_put_bignum(public_key->e); |
930 | 941 | packet_put_bignum(public_key->n); | |
931 | /* Store our public host RSA key. */ | 942 | |
932 | packet_put_int(BN_num_bits(sensitive_data.host_key->n)); | 943 | /* Store our public host RSA key. */ |
933 | packet_put_bignum(sensitive_data.host_key->e); | 944 | packet_put_int(BN_num_bits(sensitive_data.host_key->n)); |
934 | packet_put_bignum(sensitive_data.host_key->n); | 945 | packet_put_bignum(sensitive_data.host_key->e); |
935 | 946 | packet_put_bignum(sensitive_data.host_key->n); | |
936 | /* Put protocol flags. */ | 947 | |
937 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); | 948 | /* Put protocol flags. */ |
938 | 949 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); | |
939 | /* Declare which ciphers we support. */ | 950 | |
940 | packet_put_int(cipher_mask()); | 951 | /* Declare which ciphers we support. */ |
941 | 952 | packet_put_int(cipher_mask()); | |
942 | /* Declare supported authentication types. */ | 953 | |
943 | auth_mask = 0; | 954 | /* Declare supported authentication types. */ |
944 | if (options.rhosts_authentication) | 955 | auth_mask = 0; |
945 | auth_mask |= 1 << SSH_AUTH_RHOSTS; | 956 | if (options.rhosts_authentication) |
946 | if (options.rhosts_rsa_authentication) | 957 | auth_mask |= 1 << SSH_AUTH_RHOSTS; |
947 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; | 958 | if (options.rhosts_rsa_authentication) |
948 | if (options.rsa_authentication) | 959 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; |
949 | auth_mask |= 1 << SSH_AUTH_RSA; | 960 | if (options.rsa_authentication) |
961 | auth_mask |= 1 << SSH_AUTH_RSA; | ||
950 | #ifdef KRB4 | 962 | #ifdef KRB4 |
951 | if (options.kerberos_authentication) | 963 | if (options.kerberos_authentication) |
952 | auth_mask |= 1 << SSH_AUTH_KERBEROS; | 964 | auth_mask |= 1 << SSH_AUTH_KERBEROS; |
953 | #endif | 965 | #endif |
954 | #ifdef AFS | 966 | #ifdef AFS |
955 | if (options.kerberos_tgt_passing) | 967 | if (options.kerberos_tgt_passing) |
956 | auth_mask |= 1 << SSH_PASS_KERBEROS_TGT; | 968 | auth_mask |= 1 << SSH_PASS_KERBEROS_TGT; |
957 | if (options.afs_token_passing) | 969 | if (options.afs_token_passing) |
958 | auth_mask |= 1 << SSH_PASS_AFS_TOKEN; | 970 | auth_mask |= 1 << SSH_PASS_AFS_TOKEN; |
959 | #endif | 971 | #endif |
960 | if (options.password_authentication) | 972 | #ifdef SKEY |
961 | auth_mask |= 1 << SSH_AUTH_PASSWORD; | 973 | if (options.skey_authentication == 1) |
962 | packet_put_int(auth_mask); | 974 | auth_mask |= 1 << SSH_AUTH_TIS; |
963 | 975 | #endif | |
964 | /* Send the packet and wait for it to be sent. */ | 976 | if (options.password_authentication) |
965 | packet_send(); | 977 | auth_mask |= 1 << SSH_AUTH_PASSWORD; |
966 | packet_write_wait(); | 978 | packet_put_int(auth_mask); |
967 | 979 | ||
968 | debug("Sent %d bit public key and %d bit host key.", | 980 | /* Send the packet and wait for it to be sent. */ |
969 | BN_num_bits(public_key->n), BN_num_bits(sensitive_data.host_key->n)); | 981 | packet_send(); |
970 | 982 | packet_write_wait(); | |
971 | /* Read clients reply (cipher type and session key). */ | 983 | |
972 | packet_read_expect(&plen, SSH_CMSG_SESSION_KEY); | 984 | debug("Sent %d bit public key and %d bit host key.", |
973 | 985 | BN_num_bits(public_key->n), BN_num_bits(sensitive_data.host_key->n)); | |
974 | /* Get cipher type. */ | 986 | |
975 | cipher_type = packet_get_char(); | 987 | /* Read clients reply (cipher type and session key). */ |
976 | 988 | packet_read_expect(&plen, SSH_CMSG_SESSION_KEY); | |
977 | /* Get check bytes from the packet. These must match those we sent earlier | 989 | |
978 | with the public key packet. */ | 990 | /* Get cipher type. */ |
979 | for (i = 0; i < 8; i++) | 991 | cipher_type = packet_get_char(); |
980 | if (check_bytes[i] != packet_get_char()) | 992 | |
981 | packet_disconnect("IP Spoofing check bytes do not match."); | 993 | /* Get check bytes from the packet. These must match those we |
982 | 994 | sent earlier with the public key packet. */ | |
983 | debug("Encryption type: %.200s", cipher_name(cipher_type)); | 995 | for (i = 0; i < 8; i++) |
984 | 996 | if (check_bytes[i] != packet_get_char()) | |
985 | /* Get the encrypted integer. */ | 997 | packet_disconnect("IP Spoofing check bytes do not match."); |
986 | session_key_int = BN_new(); | 998 | |
987 | packet_get_bignum(session_key_int, &slen); | 999 | debug("Encryption type: %.200s", cipher_name(cipher_type)); |
988 | 1000 | ||
989 | /* Get protocol flags. */ | 1001 | /* Get the encrypted integer. */ |
990 | protocol_flags = packet_get_int(); | 1002 | session_key_int = BN_new(); |
991 | packet_set_protocol_flags(protocol_flags); | 1003 | packet_get_bignum(session_key_int, &slen); |
992 | 1004 | ||
993 | packet_integrity_check(plen, 1 + 8 + slen + 4, SSH_CMSG_SESSION_KEY); | 1005 | /* Get protocol flags. */ |
994 | 1006 | protocol_flags = packet_get_int(); | |
995 | /* Decrypt it using our private server key and private host key (key with | 1007 | packet_set_protocol_flags(protocol_flags); |
996 | larger modulus first). */ | 1008 | |
997 | if (BN_cmp(sensitive_data.private_key->n, sensitive_data.host_key->n) > 0) | 1009 | packet_integrity_check(plen, 1 + 8 + slen + 4, SSH_CMSG_SESSION_KEY); |
998 | { | 1010 | |
999 | /* Private key has bigger modulus. */ | 1011 | /* Decrypt it using our private server key and private host key |
1000 | if (BN_num_bits(sensitive_data.private_key->n) < | 1012 | (key with larger modulus first). */ |
1001 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) { | 1013 | if (BN_cmp(sensitive_data.private_key->n, sensitive_data.host_key->n) > 0) { |
1002 | fatal("do_connection: private_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", | 1014 | /* Private key has bigger modulus. */ |
1003 | BN_num_bits(sensitive_data.private_key->n), | 1015 | if (BN_num_bits(sensitive_data.private_key->n) < |
1004 | BN_num_bits(sensitive_data.host_key->n), | 1016 | BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) { |
1005 | SSH_KEY_BITS_RESERVED); | 1017 | fatal("do_connection: %s: private_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", |
1006 | } | 1018 | get_remote_ipaddr(), |
1007 | 1019 | BN_num_bits(sensitive_data.private_key->n), | |
1008 | rsa_private_decrypt(session_key_int, session_key_int, | 1020 | BN_num_bits(sensitive_data.host_key->n), |
1009 | sensitive_data.private_key); | 1021 | SSH_KEY_BITS_RESERVED); |
1010 | rsa_private_decrypt(session_key_int, session_key_int, | 1022 | } |
1011 | sensitive_data.host_key); | 1023 | rsa_private_decrypt(session_key_int, session_key_int, |
1012 | } | 1024 | sensitive_data.private_key); |
1013 | else | 1025 | rsa_private_decrypt(session_key_int, session_key_int, |
1014 | { | 1026 | sensitive_data.host_key); |
1015 | /* Host key has bigger modulus (or they are equal). */ | 1027 | } else { |
1016 | if (BN_num_bits(sensitive_data.host_key->n) < | 1028 | /* Host key has bigger modulus (or they are equal). */ |
1017 | BN_num_bits(sensitive_data.private_key->n) + SSH_KEY_BITS_RESERVED) { | 1029 | if (BN_num_bits(sensitive_data.host_key->n) < |
1018 | fatal("do_connection: host_key %d < private_key %d + SSH_KEY_BITS_RESERVED %d", | 1030 | BN_num_bits(sensitive_data.private_key->n) + SSH_KEY_BITS_RESERVED) { |
1019 | BN_num_bits(sensitive_data.host_key->n), | 1031 | fatal("do_connection: %s: host_key %d < private_key %d + SSH_KEY_BITS_RESERVED %d", |
1020 | BN_num_bits(sensitive_data.private_key->n), | 1032 | get_remote_ipaddr(), |
1021 | SSH_KEY_BITS_RESERVED); | 1033 | BN_num_bits(sensitive_data.host_key->n), |
1022 | } | 1034 | BN_num_bits(sensitive_data.private_key->n), |
1023 | rsa_private_decrypt(session_key_int, session_key_int, | 1035 | SSH_KEY_BITS_RESERVED); |
1024 | sensitive_data.host_key); | 1036 | } |
1025 | rsa_private_decrypt(session_key_int, session_key_int, | 1037 | rsa_private_decrypt(session_key_int, session_key_int, |
1026 | sensitive_data.private_key); | 1038 | sensitive_data.host_key); |
1027 | } | 1039 | rsa_private_decrypt(session_key_int, session_key_int, |
1028 | 1040 | sensitive_data.private_key); | |
1029 | /* Compute session id for this session. */ | 1041 | } |
1030 | compute_session_id(session_id, check_bytes, | 1042 | |
1031 | sensitive_data.host_key->n, | 1043 | /* Compute session id for this session. */ |
1032 | sensitive_data.private_key->n); | 1044 | compute_session_id(session_id, check_bytes, |
1033 | 1045 | sensitive_data.host_key->n, | |
1034 | /* Extract session key from the decrypted integer. The key is in the | 1046 | sensitive_data.private_key->n); |
1035 | least significant 256 bits of the integer; the first byte of the | 1047 | |
1036 | key is in the highest bits. */ | 1048 | /* Extract session key from the decrypted integer. The key is in |
1037 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); | 1049 | the least significant 256 bits of the integer; the first byte |
1038 | len = BN_num_bytes(session_key_int); | 1050 | of the key is in the highest bits. */ |
1039 | if (len < 0 || len > sizeof(session_key)) | 1051 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); |
1040 | fatal("do_connection: bad len: session_key_int %d > sizeof(session_key) %d", | 1052 | len = BN_num_bytes(session_key_int); |
1041 | len, sizeof(session_key)); | 1053 | if (len < 0 || len > sizeof(session_key)) |
1042 | memset(session_key, 0, sizeof(session_key)); | 1054 | fatal("do_connection: bad len from %s: session_key_int %d > sizeof(session_key) %d", |
1043 | BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len); | 1055 | get_remote_ipaddr(), |
1044 | 1056 | len, sizeof(session_key)); | |
1045 | /* Xor the first 16 bytes of the session key with the session id. */ | 1057 | memset(session_key, 0, sizeof(session_key)); |
1046 | for (i = 0; i < 16; i++) | 1058 | BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len); |
1047 | session_key[i] ^= session_id[i]; | 1059 | |
1048 | 1060 | /* Xor the first 16 bytes of the session key with the session id. */ | |
1049 | /* Destroy the decrypted integer. It is no longer needed. */ | 1061 | for (i = 0; i < 16; i++) |
1050 | BN_clear_free(session_key_int); | 1062 | session_key[i] ^= session_id[i]; |
1051 | 1063 | ||
1052 | /* Set the session key. From this on all communications will be | 1064 | /* Destroy the decrypted integer. It is no longer needed. */ |
1053 | encrypted. */ | 1065 | BN_clear_free(session_key_int); |
1054 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); | 1066 | |
1055 | 1067 | /* Set the session key. From this on all communications will be encrypted. */ | |
1056 | /* Destroy our copy of the session key. It is no longer needed. */ | 1068 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); |
1057 | memset(session_key, 0, sizeof(session_key)); | 1069 | |
1058 | 1070 | /* Destroy our copy of the session key. It is no longer needed. */ | |
1059 | debug("Received session key; encryption turned on."); | 1071 | memset(session_key, 0, sizeof(session_key)); |
1060 | 1072 | ||
1061 | /* Send an acknowledgement packet. Note that this packet is sent | 1073 | debug("Received session key; encryption turned on."); |
1062 | encrypted. */ | 1074 | |
1063 | packet_start(SSH_SMSG_SUCCESS); | 1075 | /* Send an acknowledgement packet. Note that this packet is sent encrypted. */ |
1064 | packet_send(); | 1076 | packet_start(SSH_SMSG_SUCCESS); |
1065 | packet_write_wait(); | 1077 | packet_send(); |
1066 | 1078 | packet_write_wait(); | |
1067 | /* Get the name of the user that we wish to log in as. */ | 1079 | |
1068 | packet_read_expect(&plen, SSH_CMSG_USER); | 1080 | /* Get the name of the user that we wish to log in as. */ |
1069 | 1081 | packet_read_expect(&plen, SSH_CMSG_USER); | |
1070 | /* Get the user name. */ | 1082 | |
1071 | { | 1083 | /* Get the user name. */ |
1072 | int ulen; | 1084 | { |
1073 | user = packet_get_string(&ulen); | 1085 | int ulen; |
1074 | packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); | 1086 | user = packet_get_string(&ulen); |
1075 | } | 1087 | packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER); |
1076 | 1088 | } | |
1077 | /* Destroy the private and public keys. They will no longer be needed. */ | 1089 | |
1078 | RSA_free(public_key); | 1090 | /* Destroy the private and public keys. They will no longer be needed. */ |
1079 | RSA_free(sensitive_data.private_key); | 1091 | RSA_free(public_key); |
1080 | RSA_free(sensitive_data.host_key); | 1092 | RSA_free(sensitive_data.private_key); |
1081 | 1093 | RSA_free(sensitive_data.host_key); | |
1082 | setproctitle("%s", user); | ||
1083 | /* Do the authentication. */ | ||
1084 | do_authentication(user); | ||
1085 | } | ||
1086 | 1094 | ||
1087 | /* Check if the user is allowed to log in via ssh. If user is listed in | 1095 | setproctitle("%s", user); |
1088 | DenyUsers or user's primary group is listed in DenyGroups, false will | 1096 | /* Do the authentication. */ |
1089 | be returned. If AllowUsers isn't empty and user isn't listed there, or | 1097 | do_authentication(user); |
1090 | if AllowGroups isn't empty and user isn't listed there, false will be | 1098 | } |
1091 | returned. Otherwise true is returned. | ||
1092 | XXX This function should also check if user has a valid shell */ | ||
1093 | 1099 | ||
1100 | /* | ||
1101 | * Check if the user is allowed to log in via ssh. If user is listed in | ||
1102 | * DenyUsers or user's primary group is listed in DenyGroups, false will | ||
1103 | * be returned. If AllowUsers isn't empty and user isn't listed there, or | ||
1104 | * if AllowGroups isn't empty and user isn't listed there, false will be | ||
1105 | * returned. Otherwise true is returned. | ||
1106 | * XXX This function should also check if user has a valid shell | ||
1107 | */ | ||
1094 | static int | 1108 | static int |
1095 | allowed_user(struct passwd *pw) | 1109 | allowed_user(struct passwd * pw) |
1096 | { | 1110 | { |
1097 | struct group *grp; | 1111 | struct group *grp; |
1098 | int i; | 1112 | int i; |
1099 | 1113 | ||
1100 | /* Shouldn't be called if pw is NULL, but better safe than sorry... */ | 1114 | /* Shouldn't be called if pw is NULL, but better safe than sorry... */ |
1101 | if (!pw) | 1115 | if (!pw) |
1102 | return 0; | 1116 | return 0; |
1103 | 1117 | ||
1104 | /* XXX Should check for valid login shell */ | 1118 | /* XXX Should check for valid login shell */ |
1105 | 1119 | ||
1106 | /* Return false if user is listed in DenyUsers */ | 1120 | /* Return false if user is listed in DenyUsers */ |
1107 | if (options.num_deny_users > 0) | 1121 | if (options.num_deny_users > 0) { |
1108 | { | 1122 | if (!pw->pw_name) |
1109 | if (!pw->pw_name) | 1123 | return 0; |
1110 | return 0; | 1124 | for (i = 0; i < options.num_deny_users; i++) |
1111 | for (i = 0; i < options.num_deny_users; i++) | 1125 | if (match_pattern(pw->pw_name, options.deny_users[i])) |
1112 | if (match_pattern(pw->pw_name, options.deny_users[i])) | 1126 | return 0; |
1113 | return 0; | 1127 | } |
1114 | } | 1128 | /* Return false if AllowUsers isn't empty and user isn't listed |
1115 | 1129 | there */ | |
1116 | /* Return false if AllowUsers isn't empty and user isn't listed there */ | 1130 | if (options.num_allow_users > 0) { |
1117 | if (options.num_allow_users > 0) | 1131 | if (!pw->pw_name) |
1118 | { | 1132 | return 0; |
1119 | if (!pw->pw_name) | 1133 | for (i = 0; i < options.num_allow_users; i++) |
1120 | return 0; | 1134 | if (match_pattern(pw->pw_name, options.allow_users[i])) |
1121 | for (i = 0; i < options.num_allow_users; i++) | 1135 | break; |
1122 | if (match_pattern(pw->pw_name, options.allow_users[i])) | 1136 | /* i < options.num_allow_users iff we break for loop */ |
1123 | break; | 1137 | if (i >= options.num_allow_users) |
1124 | /* i < options.num_allow_users iff we break for loop */ | 1138 | return 0; |
1125 | if (i >= options.num_allow_users) | 1139 | } |
1126 | return 0; | 1140 | /* Get the primary group name if we need it. Return false if it fails */ |
1127 | } | 1141 | if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { |
1128 | 1142 | grp = getgrgid(pw->pw_gid); | |
1129 | /* Get the primary group name if we need it. Return false if it fails */ | 1143 | if (!grp) |
1130 | if (options.num_deny_groups > 0 || options.num_allow_groups > 0 ) | 1144 | return 0; |
1131 | { | 1145 | |
1132 | grp = getgrgid(pw->pw_gid); | 1146 | /* Return false if user's group is listed in DenyGroups */ |
1133 | if (!grp) | 1147 | if (options.num_deny_groups > 0) { |
1134 | return 0; | 1148 | if (!grp->gr_name) |
1135 | 1149 | return 0; | |
1136 | /* Return false if user's group is listed in DenyGroups */ | 1150 | for (i = 0; i < options.num_deny_groups; i++) |
1137 | if (options.num_deny_groups > 0) | 1151 | if (match_pattern(grp->gr_name, options.deny_groups[i])) |
1138 | { | 1152 | return 0; |
1139 | if (!grp->gr_name) | 1153 | } |
1140 | return 0; | 1154 | /* Return false if AllowGroups isn't empty and user's |
1141 | for (i = 0; i < options.num_deny_groups; i++) | 1155 | group isn't listed there */ |
1142 | if (match_pattern(grp->gr_name, options.deny_groups[i])) | 1156 | if (options.num_allow_groups > 0) { |
1143 | return 0; | 1157 | if (!grp->gr_name) |
1144 | } | 1158 | return 0; |
1145 | 1159 | for (i = 0; i < options.num_allow_groups; i++) | |
1146 | /* Return false if AllowGroups isn't empty and user's group isn't | 1160 | if (match_pattern(grp->gr_name, options.allow_groups[i])) |
1147 | listed there */ | 1161 | break; |
1148 | if (options.num_allow_groups > 0) | 1162 | /* i < options.num_allow_groups iff we break for |
1149 | { | 1163 | loop */ |
1150 | if (!grp->gr_name) | 1164 | if (i >= options.num_allow_groups) |
1151 | return 0; | 1165 | return 0; |
1152 | for (i = 0; i < options.num_allow_groups; i++) | 1166 | } |
1153 | if (match_pattern(grp->gr_name, options.allow_groups[i])) | 1167 | } |
1154 | break; | 1168 | /* We found no reason not to let this user try to log on... */ |
1155 | /* i < options.num_allow_groups iff we break for loop */ | 1169 | return 1; |
1156 | if (i >= options.num_allow_groups) | ||
1157 | return 0; | ||
1158 | } | ||
1159 | } | ||
1160 | |||
1161 | /* We found no reason not to let this user try to log on... */ | ||
1162 | return 1; | ||
1163 | } | 1170 | } |
1164 | 1171 | ||
1165 | /* Performs authentication of an incoming connection. Session key has already | 1172 | /* |
1166 | been exchanged and encryption is enabled. User is the user name to log | 1173 | * Performs authentication of an incoming connection. Session key has already |
1167 | in as (received from the client). */ | 1174 | * been exchanged and encryption is enabled. User is the user name to log |
1168 | 1175 | * in as (received from the client). | |
1176 | */ | ||
1169 | void | 1177 | void |
1170 | do_authentication(char *user) | 1178 | do_authentication(char *user) |
1171 | { | 1179 | { |
1172 | struct passwd *pw, pwcopy; | 1180 | struct passwd *pw, pwcopy; |
1173 | 1181 | ||
1174 | #ifdef AFS | 1182 | #ifdef AFS |
1175 | /* If machine has AFS, set process authentication group. */ | 1183 | /* If machine has AFS, set process authentication group. */ |
1176 | if (k_hasafs()) { | 1184 | if (k_hasafs()) { |
1177 | k_setpag(); | 1185 | k_setpag(); |
1178 | k_unlog(); | 1186 | k_unlog(); |
1179 | } | 1187 | } |
1180 | #endif /* AFS */ | 1188 | #endif /* AFS */ |
1181 | 1189 | ||
1182 | /* Verify that the user is a valid user. */ | 1190 | /* Verify that the user is a valid user. */ |
1183 | pw = getpwnam(user); | 1191 | pw = getpwnam(user); |
1184 | if (!pw || !allowed_user(pw)) | 1192 | if (!pw || !allowed_user(pw)) |
1185 | do_fake_authloop(user); | 1193 | do_fake_authloop(user); |
1186 | 1194 | ||
1187 | /* Take a copy of the returned structure. */ | 1195 | /* Take a copy of the returned structure. */ |
1188 | memset(&pwcopy, 0, sizeof(pwcopy)); | 1196 | memset(&pwcopy, 0, sizeof(pwcopy)); |
1189 | pwcopy.pw_name = xstrdup(pw->pw_name); | 1197 | pwcopy.pw_name = xstrdup(pw->pw_name); |
1190 | pwcopy.pw_passwd = xstrdup(pw->pw_passwd); | 1198 | pwcopy.pw_passwd = xstrdup(pw->pw_passwd); |
1191 | pwcopy.pw_uid = pw->pw_uid; | 1199 | pwcopy.pw_uid = pw->pw_uid; |
1192 | pwcopy.pw_gid = pw->pw_gid; | 1200 | pwcopy.pw_gid = pw->pw_gid; |
1193 | pwcopy.pw_dir = xstrdup(pw->pw_dir); | 1201 | pwcopy.pw_dir = xstrdup(pw->pw_dir); |
1194 | pwcopy.pw_shell = xstrdup(pw->pw_shell); | 1202 | pwcopy.pw_shell = xstrdup(pw->pw_shell); |
1195 | pw = &pwcopy; | 1203 | pw = &pwcopy; |
1196 | 1204 | ||
1197 | #ifdef HAVE_LIBPAM | 1205 | #ifdef HAVE_LIBPAM |
1198 | { | 1206 | { |
1199 | int pam_retval; | 1207 | int pam_retval; |
1200 | 1208 | ||
1201 | debug("Starting up PAM with username \"%.200s\"", pw->pw_name); | 1209 | debug("Starting up PAM with username \"%.200s\"", pw->pw_name); |
1202 | 1210 | ||
1203 | pam_retval = pam_start("sshd", pw->pw_name, &conv, (pam_handle_t**)&pamh); | 1211 | pam_retval = pam_start("sshd", pw->pw_name, &conv, (pam_handle_t**)&pamh); |
1204 | if (pam_retval != PAM_SUCCESS) | 1212 | if (pam_retval != PAM_SUCCESS) |
1205 | fatal("PAM initialisation failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); | 1213 | fatal("PAM initialisation failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); |
1206 | 1214 | ||
1207 | fatal_add_cleanup(&pam_cleanup_proc, NULL); | 1215 | fatal_add_cleanup(&pam_cleanup_proc, NULL); |
1208 | } | 1216 | } |
1209 | #endif | 1217 | #endif |
1210 | 1218 | ||
1211 | /* If we are not running as root, the user must have the same uid as the | 1219 | /* If we are not running as root, the user must have the same uid |
1212 | server. */ | 1220 | as the server. */ |
1213 | if (getuid() != 0 && pw->pw_uid != getuid()) | 1221 | if (getuid() != 0 && pw->pw_uid != getuid()) |
1214 | packet_disconnect("Cannot change user when server not running as root."); | 1222 | packet_disconnect("Cannot change user when server not running as root."); |
1215 | 1223 | ||
1216 | debug("Attempting authentication for %.100s.", user); | 1224 | debug("Attempting authentication for %.100s.", user); |
1217 | 1225 | ||
1218 | /* If the user has no password, accept authentication immediately. */ | 1226 | /* If the user has no password, accept authentication immediately. */ |
1219 | if (options.password_authentication && | 1227 | if (options.password_authentication && |
1220 | #ifdef KRB4 | 1228 | #ifdef KRB4 |
1221 | (!options.kerberos_authentication || options.kerberos_or_local_passwd) && | 1229 | (!options.kerberos_authentication || options.kerberos_or_local_passwd) && |
1222 | #endif /* KRB4 */ | 1230 | #endif /* KRB4 */ |
1223 | auth_password(pw, "")) | 1231 | auth_password(pw, "")) { |
1224 | { | 1232 | /* Authentication with empty password succeeded. */ |
1225 | /* Authentication with empty password succeeded. */ | 1233 | log("Login for user %s from %.100s, accepted without authentication.", |
1226 | debug("Login for user %.100s accepted without authentication.", user); | 1234 | pw->pw_name, get_remote_ipaddr()); |
1227 | } else { | 1235 | } else { |
1228 | /* Loop until the user has been authenticated or the connection is closed, | 1236 | /* Loop until the user has been authenticated or the |
1229 | do_authloop() returns only if authentication is successfull */ | 1237 | connection is closed, do_authloop() returns only if |
1230 | do_authloop(pw); | 1238 | authentication is successfull */ |
1231 | } | 1239 | do_authloop(pw); |
1232 | 1240 | } | |
1233 | /* XXX log unified auth message */ | 1241 | |
1234 | 1242 | /* Check if the user is logging in as root and root logins are disallowed. */ | |
1235 | /* Check if the user is logging in as root and root logins are disallowed. */ | 1243 | if (pw->pw_uid == 0 && !options.permit_root_login) { |
1236 | if (pw->pw_uid == 0 && !options.permit_root_login) | 1244 | if (forced_command) |
1237 | { | 1245 | log("Root login accepted for forced command."); |
1238 | if (forced_command) | 1246 | else |
1239 | log("Root login accepted for forced command."); | 1247 | packet_disconnect("ROOT LOGIN REFUSED FROM %.200s", |
1240 | else | 1248 | get_canonical_hostname()); |
1241 | packet_disconnect("ROOT LOGIN REFUSED FROM %.200s", | 1249 | } |
1242 | get_canonical_hostname()); | 1250 | /* The user has been authenticated and accepted. */ |
1243 | } | 1251 | packet_start(SSH_SMSG_SUCCESS); |
1244 | 1252 | packet_send(); | |
1245 | /* The user has been authenticated and accepted. */ | 1253 | packet_write_wait(); |
1246 | packet_start(SSH_SMSG_SUCCESS); | 1254 | |
1247 | packet_send(); | 1255 | /* Perform session preparation. */ |
1248 | packet_write_wait(); | 1256 | do_authenticated(pw); |
1249 | |||
1250 | /* Perform session preparation. */ | ||
1251 | do_authenticated(pw); | ||
1252 | } | 1257 | } |
1253 | 1258 | ||
1254 | #define MAX_AUTH_FAILURES 5 | 1259 | #define AUTH_FAIL_MAX 6 |
1260 | #define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2) | ||
1261 | #define AUTH_FAIL_MSG "Too many authentication failures for %.100s" | ||
1255 | 1262 | ||
1256 | /* read packets and try to authenticate local user *pw. | 1263 | /* |
1257 | return if authentication is successfull */ | 1264 | * read packets and try to authenticate local user *pw. |
1265 | * return if authentication is successfull | ||
1266 | */ | ||
1258 | void | 1267 | void |
1259 | do_authloop(struct passwd *pw) | 1268 | do_authloop(struct passwd * pw) |
1260 | { | 1269 | { |
1261 | int authentication_failures = 0; | 1270 | int attempt = 0; |
1262 | unsigned int bits; | 1271 | unsigned int bits; |
1263 | BIGNUM *client_host_key_e, *client_host_key_n; | 1272 | BIGNUM *client_host_key_e, *client_host_key_n; |
1264 | BIGNUM *n; | 1273 | BIGNUM *n; |
1265 | char *client_user = NULL, *password = NULL; | 1274 | char *client_user = NULL, *password = NULL; |
1266 | int plen, dlen, nlen, ulen, elen; | 1275 | char user[1024]; |
1276 | int plen, dlen, nlen, ulen, elen; | ||
1277 | int type = 0; | ||
1278 | void (*authlog) (const char *fmt,...) = verbose; | ||
1267 | #ifdef HAVE_LIBPAM | 1279 | #ifdef HAVE_LIBPAM |
1268 | int pam_retval; | 1280 | int pam_retval; |
1269 | #endif /* HAVE_LIBPAM */ | 1281 | #endif /* HAVE_LIBPAM */ |
1270 | 1282 | ||
1271 | /* Indicate that authentication is needed. */ | 1283 | /* Indicate that authentication is needed. */ |
1272 | packet_start(SSH_SMSG_FAILURE); | 1284 | packet_start(SSH_SMSG_FAILURE); |
1273 | packet_send(); | 1285 | packet_send(); |
1274 | packet_write_wait(); | 1286 | packet_write_wait(); |
1275 | 1287 | ||
1276 | for (;;) { | 1288 | for (attempt = 1;; attempt++) { |
1277 | int authenticated = 0; | 1289 | int authenticated = 0; |
1290 | strlcpy(user, "", sizeof user); | ||
1278 | 1291 | ||
1279 | /* Get a packet from the client. */ | 1292 | /* Get a packet from the client. */ |
1280 | int type = packet_read(&plen); | 1293 | type = packet_read(&plen); |
1281 | 1294 | ||
1282 | /* Process the packet. */ | 1295 | /* Process the packet. */ |
1283 | switch (type) | 1296 | switch (type) { |
1284 | { | ||
1285 | #ifdef AFS | 1297 | #ifdef AFS |
1286 | case SSH_CMSG_HAVE_KERBEROS_TGT: | 1298 | case SSH_CMSG_HAVE_KERBEROS_TGT: |
1287 | if (!options.kerberos_tgt_passing) | 1299 | if (!options.kerberos_tgt_passing) { |
1288 | { | 1300 | /* packet_get_all(); */ |
1289 | /* packet_get_all(); */ | 1301 | verbose("Kerberos tgt passing disabled."); |
1290 | log("Kerberos tgt passing disabled."); | 1302 | break; |
1291 | break; | 1303 | } else { |
1292 | } | 1304 | /* Accept Kerberos tgt. */ |
1293 | else { | 1305 | char *tgt = packet_get_string(&dlen); |
1294 | /* Accept Kerberos tgt. */ | 1306 | packet_integrity_check(plen, 4 + dlen, type); |
1295 | char *tgt = packet_get_string(&dlen); | 1307 | if (!auth_kerberos_tgt(pw, tgt)) |
1296 | packet_integrity_check(plen, 4 + dlen, type); | 1308 | verbose("Kerberos tgt REFUSED for %s", pw->pw_name); |
1297 | if (!auth_kerberos_tgt(pw, tgt)) | 1309 | xfree(tgt); |
1298 | debug("Kerberos tgt REFUSED for %s", pw->pw_name); | 1310 | } |
1299 | xfree(tgt); | 1311 | continue; |
1300 | } | 1312 | |
1301 | continue; | 1313 | case SSH_CMSG_HAVE_AFS_TOKEN: |
1302 | 1314 | if (!options.afs_token_passing || !k_hasafs()) { | |
1303 | case SSH_CMSG_HAVE_AFS_TOKEN: | 1315 | /* packet_get_all(); */ |
1304 | if (!options.afs_token_passing || !k_hasafs()) { | 1316 | verbose("AFS token passing disabled."); |
1305 | /* packet_get_all(); */ | 1317 | break; |
1306 | log("AFS token passing disabled."); | 1318 | } else { |
1307 | break; | 1319 | /* Accept AFS token. */ |
1308 | } | 1320 | char *token_string = packet_get_string(&dlen); |
1309 | else { | 1321 | packet_integrity_check(plen, 4 + dlen, type); |
1310 | /* Accept AFS token. */ | 1322 | if (!auth_afs_token(pw, token_string)) |
1311 | char *token_string = packet_get_string(&dlen); | 1323 | verbose("AFS token REFUSED for %s", pw->pw_name); |
1312 | packet_integrity_check(plen, 4 + dlen, type); | 1324 | xfree(token_string); |
1313 | if (!auth_afs_token(pw, token_string)) | 1325 | } |
1314 | debug("AFS token REFUSED for %s", pw->pw_name); | 1326 | continue; |
1315 | xfree(token_string); | ||
1316 | } | ||
1317 | continue; | ||
1318 | #endif /* AFS */ | 1327 | #endif /* AFS */ |
1319 | |||
1320 | #ifdef KRB4 | 1328 | #ifdef KRB4 |
1321 | case SSH_CMSG_AUTH_KERBEROS: | 1329 | case SSH_CMSG_AUTH_KERBEROS: |
1322 | if (!options.kerberos_authentication) | 1330 | if (!options.kerberos_authentication) { |
1323 | { | 1331 | /* packet_get_all(); */ |
1324 | /* packet_get_all(); */ | 1332 | verbose("Kerberos authentication disabled."); |
1325 | log("Kerberos authentication disabled."); | 1333 | break; |
1326 | break; | 1334 | } else { |
1327 | } | 1335 | /* Try Kerberos v4 authentication. */ |
1328 | else { | 1336 | KTEXT_ST auth; |
1329 | /* Try Kerberos v4 authentication. */ | 1337 | char *tkt_user = NULL; |
1330 | KTEXT_ST auth; | 1338 | char *kdata = packet_get_string((unsigned int *) &auth.length); |
1331 | char *tkt_user = NULL; | 1339 | packet_integrity_check(plen, 4 + auth.length, type); |
1332 | char *kdata = packet_get_string((unsigned int *)&auth.length); | 1340 | |
1333 | packet_integrity_check(plen, 4 + auth.length, type); | 1341 | if (auth.length < MAX_KTXT_LEN) |
1334 | 1342 | memcpy(auth.dat, kdata, auth.length); | |
1335 | if (auth.length < MAX_KTXT_LEN) | 1343 | xfree(kdata); |
1336 | memcpy(auth.dat, kdata, auth.length); | 1344 | |
1337 | xfree(kdata); | 1345 | authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); |
1338 | 1346 | ||
1339 | authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user); | 1347 | if (authenticated) { |
1340 | 1348 | snprintf(user, sizeof user, " tktuser %s", tkt_user); | |
1341 | log("Kerberos authentication %s%s for account %s from %s", | 1349 | xfree(tkt_user); |
1342 | authenticated ? "accepted " : "failed", | 1350 | } |
1343 | tkt_user != NULL ? tkt_user : "", | 1351 | } |
1344 | pw->pw_name, get_canonical_hostname()); | 1352 | break; |
1345 | if (authenticated) | ||
1346 | xfree(tkt_user); | ||
1347 | } | ||
1348 | break; | ||
1349 | #endif /* KRB4 */ | 1353 | #endif /* KRB4 */ |
1350 | 1354 | ||
1351 | case SSH_CMSG_AUTH_RHOSTS: | 1355 | case SSH_CMSG_AUTH_RHOSTS: |
1352 | if (!options.rhosts_authentication) | 1356 | if (!options.rhosts_authentication) { |
1353 | { | 1357 | verbose("Rhosts authentication disabled."); |
1354 | log("Rhosts authentication disabled."); | 1358 | break; |
1355 | break; | 1359 | } |
1356 | } | 1360 | /* Get client user name. Note that we just have |
1357 | 1361 | to trust the client; this is one reason why | |
1358 | /* Get client user name. Note that we just have to trust the client; | 1362 | rhosts authentication is insecure. (Another is |
1359 | this is one reason why rhosts authentication is insecure. | 1363 | IP-spoofing on a local network.) */ |
1360 | (Another is IP-spoofing on a local network.) */ | 1364 | client_user = packet_get_string(&ulen); |
1361 | client_user = packet_get_string(&dlen); | 1365 | packet_integrity_check(plen, 4 + ulen, type); |
1362 | packet_integrity_check(plen, 4 + dlen, type); | 1366 | |
1363 | 1367 | /* Try to authenticate using /etc/hosts.equiv and | |
1364 | /* Try to authenticate using /etc/hosts.equiv and .rhosts. */ | 1368 | .rhosts. */ |
1365 | authenticated = auth_rhosts(pw, client_user); | 1369 | authenticated = auth_rhosts(pw, client_user); |
1366 | 1370 | ||
1367 | log("Rhosts authentication %s for %.100s, remote %.100s on %.700s.", | 1371 | snprintf(user, sizeof user, " ruser %s", client_user); |
1368 | authenticated ? "accepted" : "failed", | ||
1369 | pw->pw_name, client_user, get_canonical_hostname()); | ||
1370 | #ifndef HAVE_LIBPAM | 1372 | #ifndef HAVE_LIBPAM |
1371 | xfree(client_user); | 1373 | xfree(client_user); |
1372 | #endif /* HAVE_LIBPAM */ | 1374 | #endif /* HAVE_LIBPAM */ |
1373 | break; | 1375 | break; |
1374 | 1376 | ||
1375 | case SSH_CMSG_AUTH_RHOSTS_RSA: | 1377 | case SSH_CMSG_AUTH_RHOSTS_RSA: |
1376 | if (!options.rhosts_rsa_authentication) | 1378 | if (!options.rhosts_rsa_authentication) { |
1377 | { | 1379 | verbose("Rhosts with RSA authentication disabled."); |
1378 | log("Rhosts with RSA authentication disabled."); | 1380 | break; |
1379 | break; | 1381 | } |
1380 | } | 1382 | /* Get client user name. Note that we just have |
1381 | 1383 | to trust the client; root on the client machine | |
1382 | /* Get client user name. Note that we just have to trust | 1384 | can claim to be any user. */ |
1383 | the client; root on the client machine can claim to be | 1385 | client_user = packet_get_string(&ulen); |
1384 | any user. */ | 1386 | |
1385 | client_user = packet_get_string(&ulen); | 1387 | /* Get the client host key. */ |
1386 | 1388 | client_host_key_e = BN_new(); | |
1387 | /* Get the client host key. */ | 1389 | client_host_key_n = BN_new(); |
1388 | client_host_key_e = BN_new(); | 1390 | bits = packet_get_int(); |
1389 | client_host_key_n = BN_new(); | 1391 | packet_get_bignum(client_host_key_e, &elen); |
1390 | bits = packet_get_int(); | 1392 | packet_get_bignum(client_host_key_n, &nlen); |
1391 | packet_get_bignum(client_host_key_e, &elen); | 1393 | |
1392 | packet_get_bignum(client_host_key_n, &nlen); | 1394 | if (bits != BN_num_bits(client_host_key_n)) |
1393 | 1395 | error("Warning: keysize mismatch for client_host_key: " | |
1394 | if (bits != BN_num_bits(client_host_key_n)) | 1396 | "actual %d, announced %d", BN_num_bits(client_host_key_n), bits); |
1395 | error("Warning: keysize mismatch for client_host_key: " | 1397 | packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); |
1396 | "actual %d, announced %d", BN_num_bits(client_host_key_n), bits); | 1398 | |
1397 | packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type); | 1399 | authenticated = auth_rhosts_rsa(pw, client_user, |
1398 | 1400 | client_host_key_e, client_host_key_n); | |
1399 | authenticated = auth_rhosts_rsa(pw, client_user, | 1401 | BN_clear_free(client_host_key_e); |
1400 | client_host_key_e, client_host_key_n); | 1402 | BN_clear_free(client_host_key_n); |
1401 | log("Rhosts authentication %s for %.100s, remote %.100s.", | 1403 | |
1402 | authenticated ? "accepted" : "failed", | 1404 | snprintf(user, sizeof user, " ruser %s", client_user); |
1403 | pw->pw_name, client_user); | ||
1404 | #ifndef HAVE_LIBPAM | 1405 | #ifndef HAVE_LIBPAM |
1405 | xfree(client_user); | 1406 | xfree(client_user); |
1406 | #endif /* HAVE_LIBPAM */ | 1407 | #endif /* HAVE_LIBPAM */ |
1407 | BN_clear_free(client_host_key_e); | 1408 | break; |
1408 | BN_clear_free(client_host_key_n); | 1409 | |
1409 | break; | 1410 | case SSH_CMSG_AUTH_RSA: |
1410 | 1411 | if (!options.rsa_authentication) { | |
1411 | case SSH_CMSG_AUTH_RSA: | 1412 | verbose("RSA authentication disabled."); |
1412 | if (!options.rsa_authentication) | 1413 | break; |
1413 | { | 1414 | } |
1414 | log("RSA authentication disabled."); | 1415 | /* RSA authentication requested. */ |
1415 | break; | 1416 | n = BN_new(); |
1416 | } | 1417 | packet_get_bignum(n, &nlen); |
1417 | 1418 | packet_integrity_check(plen, nlen, type); | |
1418 | /* RSA authentication requested. */ | 1419 | authenticated = auth_rsa(pw, n); |
1419 | n = BN_new(); | 1420 | BN_clear_free(n); |
1420 | packet_get_bignum(n, &nlen); | 1421 | break; |
1421 | packet_integrity_check(plen, nlen, type); | 1422 | |
1422 | 1423 | case SSH_CMSG_AUTH_PASSWORD: | |
1423 | authenticated = auth_rsa(pw, n); | 1424 | if (!options.password_authentication) { |
1424 | log("RSA authentication %s for %.100s.", | 1425 | verbose("Password authentication disabled."); |
1425 | authenticated ? "accepted" : "failed", | 1426 | break; |
1426 | pw->pw_name); | 1427 | } |
1427 | BN_clear_free(n); | 1428 | /* Read user password. It is in plain text, but |
1428 | break; | 1429 | was transmitted over the encrypted channel so |
1429 | 1430 | it is not visible to an outside observer. */ | |
1430 | case SSH_CMSG_AUTH_PASSWORD: | 1431 | password = packet_get_string(&dlen); |
1431 | if (!options.password_authentication) | 1432 | packet_integrity_check(plen, 4 + dlen, type); |
1432 | { | 1433 | |
1433 | log("Password authentication disabled."); | ||
1434 | break; | ||
1435 | } | ||
1436 | |||
1437 | /* Read user password. It is in plain text, but was transmitted | ||
1438 | over the encrypted channel so it is not visible to an outside | ||
1439 | observer. */ | ||
1440 | password = packet_get_string(&dlen); | ||
1441 | packet_integrity_check(plen, 4 + dlen, type); | ||
1442 | |||
1443 | #ifdef HAVE_LIBPAM | 1434 | #ifdef HAVE_LIBPAM |
1444 | /* Do PAM auth with password */ | 1435 | /* Do PAM auth with password */ |
1445 | pampasswd = password; | 1436 | pampasswd = password; |
1446 | pam_retval = pam_authenticate((pam_handle_t *)pamh, 0); | 1437 | pam_retval = pam_authenticate((pam_handle_t *)pamh, 0); |
1447 | if (pam_retval == PAM_SUCCESS) | 1438 | if (pam_retval == PAM_SUCCESS) { |
1448 | { | 1439 | log("PAM Password authentication accepted for user \"%.100s\"", pw->pw_name); |
1449 | log("PAM Password authentication accepted for user \"%.100s\"", pw->pw_name); | 1440 | authenticated = 1; |
1450 | authenticated = 1; | 1441 | break; |
1451 | break; | 1442 | } |
1452 | } | 1443 | |
1453 | 1444 | log("PAM Password authentication for \"%.100s\" failed: %s", | |
1454 | log("PAM Password authentication for \"%.100s\" failed: %s", | 1445 | pw->pw_name, PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); |
1455 | pw->pw_name, PAM_STRERROR((pam_handle_t *)pamh, pam_retval)); | 1446 | break; |
1456 | break; | ||
1457 | #else /* HAVE_LIBPAM */ | 1447 | #else /* HAVE_LIBPAM */ |
1458 | /* Try authentication with the password. */ | 1448 | /* Try authentication with the password. */ |
1459 | authenticated = auth_password(pw, password); | 1449 | authenticated = auth_password(pw, password); |
1460 | log("Password authentication %s for %.100s.", | 1450 | |
1461 | authenticated ? "accepted" : "failed", | 1451 | memset(password, 0, strlen(password)); |
1462 | pw->pw_name); | 1452 | xfree(password); |
1463 | 1453 | break; | |
1464 | memset(password, 0, strlen(password)); | ||
1465 | xfree(password); | ||
1466 | break; | ||
1467 | #endif /* HAVE_LIBPAM */ | 1454 | #endif /* HAVE_LIBPAM */ |
1468 | 1455 | ||
1469 | case SSH_CMSG_AUTH_TIS: | 1456 | #ifdef SKEY |
1470 | /* TIS Authentication is unsupported */ | 1457 | case SSH_CMSG_AUTH_TIS: |
1471 | log("TIS authentication disabled."); | 1458 | debug("rcvd SSH_CMSG_AUTH_TIS"); |
1472 | break; | 1459 | if (options.skey_authentication == 1) { |
1473 | 1460 | char *skeyinfo = skey_keyinfo(pw->pw_name); | |
1474 | default: | 1461 | if (skeyinfo == NULL) { |
1475 | /* Any unknown messages will be ignored (and failure returned) | 1462 | debug("generating fake skeyinfo for %.100s.", pw->pw_name); |
1476 | during authentication. */ | 1463 | skeyinfo = skey_fake_keyinfo(pw->pw_name); |
1477 | log("Unknown message during authentication: type %d", type); | 1464 | } |
1478 | break; /* Respond with a failure message. */ | 1465 | if (skeyinfo != NULL) { |
1479 | } | 1466 | /* we send our s/key- in |
1480 | 1467 | tis-challenge messages */ | |
1481 | if (authenticated) | 1468 | debug("sending challenge '%s'", skeyinfo); |
1482 | break; | 1469 | packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE); |
1483 | if (++authentication_failures >= MAX_AUTH_FAILURES) | 1470 | packet_put_string(skeyinfo, strlen(skeyinfo)); |
1484 | packet_disconnect("Too many authentication failures for %.100s from %.200s", | 1471 | packet_send(); |
1485 | pw->pw_name, get_canonical_hostname()); | 1472 | packet_write_wait(); |
1486 | /* Send a message indicating that the authentication attempt failed. */ | 1473 | continue; |
1487 | packet_start(SSH_SMSG_FAILURE); | 1474 | } |
1488 | packet_send(); | 1475 | } |
1489 | packet_write_wait(); | 1476 | break; |
1490 | } | 1477 | case SSH_CMSG_AUTH_TIS_RESPONSE: |
1478 | debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE"); | ||
1479 | if (options.skey_authentication == 1) { | ||
1480 | char *response = packet_get_string(&dlen); | ||
1481 | debug("skey response == '%s'", response); | ||
1482 | packet_integrity_check(plen, 4 + dlen, type); | ||
1483 | authenticated = (skey_haskey(pw->pw_name) == 0 && | ||
1484 | skey_passcheck(pw->pw_name, response) != -1); | ||
1485 | xfree(response); | ||
1486 | } | ||
1487 | break; | ||
1488 | #else | ||
1489 | case SSH_CMSG_AUTH_TIS: | ||
1490 | /* TIS Authentication is unsupported */ | ||
1491 | log("TIS authentication unsupported."); | ||
1492 | break; | ||
1493 | #endif | ||
1494 | |||
1495 | default: | ||
1496 | /* Any unknown messages will be ignored (and | ||
1497 | failure returned) during authentication. */ | ||
1498 | log("Unknown message during authentication: type %d", type); | ||
1499 | break; | ||
1500 | } | ||
1501 | |||
1502 | /* Raise logging level */ | ||
1503 | if (authenticated || | ||
1504 | attempt == AUTH_FAIL_LOG || | ||
1505 | type == SSH_CMSG_AUTH_PASSWORD) | ||
1506 | authlog = log; | ||
1507 | |||
1508 | authlog("%s %s for %.200s from %.200s port %d%s", | ||
1509 | authenticated ? "Accepted" : "Failed", | ||
1510 | get_authname(type), | ||
1511 | pw->pw_uid == 0 ? "ROOT" : pw->pw_name, | ||
1512 | get_remote_ipaddr(), | ||
1513 | get_remote_port(), | ||
1514 | user); | ||
1491 | 1515 | ||
1492 | #ifdef HAVE_LIBPAM | 1516 | #ifdef HAVE_LIBPAM |
1493 | do_pam_account_and_session(pw->pw_name, client_user, get_canonical_hostname()); | 1517 | do_pam_account_and_session(pw->pw_name, client_user, |
1518 | get_canonical_hostname()); | ||
1494 | 1519 | ||
1495 | /* Clean up */ | 1520 | /* Clean up */ |
1496 | if (client_user != NULL) | 1521 | if (client_user != NULL) |
1497 | xfree(client_user); | 1522 | xfree(client_user); |
1498 | 1523 | ||
1499 | if (password != NULL) | 1524 | if (password != NULL) { |
1500 | { | 1525 | memset(password, 0, strlen(password)); |
1501 | memset(password, 0, strlen(password)); | 1526 | xfree(password); |
1502 | xfree(password); | 1527 | } |
1503 | } | ||
1504 | #endif /* HAVE_LIBPAM */ | 1528 | #endif /* HAVE_LIBPAM */ |
1529 | |||
1530 | if (authenticated) | ||
1531 | return; | ||
1532 | |||
1533 | if (attempt > AUTH_FAIL_MAX) | ||
1534 | packet_disconnect(AUTH_FAIL_MSG, pw->pw_name); | ||
1535 | |||
1536 | /* Send a message indicating that the authentication attempt failed. */ | ||
1537 | packet_start(SSH_SMSG_FAILURE); | ||
1538 | packet_send(); | ||
1539 | packet_write_wait(); | ||
1540 | } | ||
1505 | } | 1541 | } |
1506 | 1542 | ||
1507 | /* The user does not exist or access is denied, | 1543 | /* |
1508 | but fake indication that authentication is needed. */ | 1544 | * The user does not exist or access is denied, |
1545 | * but fake indication that authentication is needed. | ||
1546 | */ | ||
1509 | void | 1547 | void |
1510 | do_fake_authloop(char *user) | 1548 | do_fake_authloop(char *user) |
1511 | { | 1549 | { |
1512 | int authentication_failures = 0; | 1550 | int attempt = 0; |
1513 | 1551 | ||
1514 | /* Indicate that authentication is needed. */ | 1552 | log("Faking authloop for illegal user %.200s from %.200s port %d", |
1515 | packet_start(SSH_SMSG_FAILURE); | 1553 | user, |
1516 | packet_send(); | 1554 | get_remote_ipaddr(), |
1517 | packet_write_wait(); | 1555 | get_remote_port()); |
1518 | 1556 | ||
1519 | /* Keep reading packets, and always respond with a failure. This is to | 1557 | /* Indicate that authentication is needed. */ |
1520 | avoid disclosing whether such a user really exists. */ | 1558 | packet_start(SSH_SMSG_FAILURE); |
1521 | for (;;) | 1559 | packet_send(); |
1522 | { | 1560 | packet_write_wait(); |
1523 | /* Read a packet. This will not return if the client disconnects. */ | 1561 | |
1524 | int plen; | 1562 | /* Keep reading packets, and always respond with a failure. This |
1525 | int type = packet_read(&plen); | 1563 | is to avoid disclosing whether such a user really exists. */ |
1564 | for (attempt = 1;; attempt++) { | ||
1565 | /* Read a packet. This will not return if the client | ||
1566 | disconnects. */ | ||
1567 | int plen; | ||
1568 | int type = packet_read(&plen); | ||
1526 | #ifdef SKEY | 1569 | #ifdef SKEY |
1527 | int passw_len; | 1570 | int dlen; |
1528 | char *password, *skeyinfo; | 1571 | char *password, *skeyinfo; |
1529 | if (options.password_authentication && | 1572 | if (options.password_authentication && |
1530 | options.skey_authentication == 1 && | 1573 | options.skey_authentication == 1 && |
1531 | type == SSH_CMSG_AUTH_PASSWORD && | 1574 | type == SSH_CMSG_AUTH_PASSWORD && |
1532 | (password = packet_get_string(&passw_len)) != NULL && | 1575 | (password = packet_get_string(&dlen)) != NULL && |
1533 | passw_len == 5 && | 1576 | dlen == 5 && |
1534 | strncasecmp(password, "s/key", 5) == 0 && | 1577 | strncasecmp(password, "s/key", 5) == 0 && |
1535 | (skeyinfo = skey_fake_keyinfo(user)) != NULL ){ | 1578 | (skeyinfo = skey_fake_keyinfo(user)) != NULL) { |
1536 | /* Send a fake s/key challenge. */ | 1579 | /* Send a fake s/key challenge. */ |
1537 | packet_send_debug(skeyinfo); | 1580 | packet_send_debug(skeyinfo); |
1538 | } | 1581 | } |
1539 | #endif | 1582 | #endif |
1540 | if (++authentication_failures >= MAX_AUTH_FAILURES) | 1583 | if (attempt > AUTH_FAIL_MAX) |
1541 | packet_disconnect("Too many authentication failures for %.100s from %.200s", | 1584 | packet_disconnect(AUTH_FAIL_MSG, user); |
1542 | user, get_canonical_hostname()); | 1585 | |
1543 | /* Send failure. This should be indistinguishable from a failed | 1586 | /* Send failure. This should be indistinguishable from a |
1544 | authentication. */ | 1587 | failed authentication. */ |
1545 | packet_start(SSH_SMSG_FAILURE); | 1588 | packet_start(SSH_SMSG_FAILURE); |
1546 | packet_send(); | 1589 | packet_send(); |
1547 | packet_write_wait(); | 1590 | packet_write_wait(); |
1548 | } | 1591 | } |
1549 | /*NOTREACHED*/ | 1592 | /* NOTREACHED */ |
1550 | abort(); | 1593 | abort(); |
1551 | } | 1594 | } |
1552 | 1595 | ||
1553 | 1596 | ||
1554 | /* Remove local Xauthority file. */ | 1597 | /* |
1598 | * Remove local Xauthority file. | ||
1599 | */ | ||
1555 | static void | 1600 | static void |
1556 | xauthfile_cleanup_proc(void *ignore) | 1601 | xauthfile_cleanup_proc(void *ignore) |
1557 | { | 1602 | { |
1558 | debug("xauthfile_cleanup_proc called"); | 1603 | debug("xauthfile_cleanup_proc called"); |
1559 | 1604 | ||
1560 | if (xauthfile != NULL) { | 1605 | if (xauthfile != NULL) { |
1561 | unlink(xauthfile); | 1606 | unlink(xauthfile); |
1562 | xfree(xauthfile); | 1607 | xfree(xauthfile); |
1563 | xauthfile = NULL; | 1608 | xauthfile = NULL; |
1564 | } | 1609 | } |
1565 | } | 1610 | } |
1566 | 1611 | ||
1567 | /* Prepares for an interactive session. This is called after the user has | 1612 | /* |
1568 | been successfully authenticated. During this message exchange, pseudo | 1613 | * Prepares for an interactive session. This is called after the user has |
1569 | terminals are allocated, X11, TCP/IP, and authentication agent forwardings | 1614 | * been successfully authenticated. During this message exchange, pseudo |
1570 | are requested, etc. */ | 1615 | * terminals are allocated, X11, TCP/IP, and authentication agent forwardings |
1571 | 1616 | * are requested, etc. | |
1572 | void do_authenticated(struct passwd *pw) | 1617 | */ |
1618 | void | ||
1619 | do_authenticated(struct passwd * pw) | ||
1573 | { | 1620 | { |
1574 | int type; | 1621 | int type; |
1575 | int compression_level = 0, enable_compression_after_reply = 0; | 1622 | int compression_level = 0, enable_compression_after_reply = 0; |
1576 | int have_pty = 0, ptyfd = -1, ttyfd = -1, xauthfd = -1; | 1623 | int have_pty = 0, ptyfd = -1, ttyfd = -1, xauthfd = -1; |
1577 | int row, col, xpixel, ypixel, screen; | 1624 | int row, col, xpixel, ypixel, screen; |
1578 | char ttyname[64]; | 1625 | char ttyname[64]; |
1579 | char *command, *term = NULL, *display = NULL, *proto = NULL, *data = NULL; | 1626 | char *command, *term = NULL, *display = NULL, *proto = NULL, |
1580 | struct group *grp; | 1627 | *data = NULL; |
1581 | gid_t tty_gid; | 1628 | struct group *grp; |
1582 | mode_t tty_mode; | 1629 | gid_t tty_gid; |
1583 | int n_bytes; | 1630 | mode_t tty_mode; |
1584 | 1631 | int n_bytes; | |
1585 | /* Cancel the alarm we set to limit the time taken for authentication. */ | 1632 | |
1586 | alarm(0); | 1633 | /* Cancel the alarm we set to limit the time taken for |
1587 | 1634 | authentication. */ | |
1588 | /* Inform the channel mechanism that we are the server side and that | 1635 | alarm(0); |
1589 | the client may request to connect to any port at all. (The user could | 1636 | |
1590 | do it anyway, and we wouldn\'t know what is permitted except by the | 1637 | /* Inform the channel mechanism that we are the server side and |
1591 | client telling us, so we can equally well trust the client not to request | 1638 | that the client may request to connect to any port at all. |
1592 | anything bogus.) */ | 1639 | (The user could do it anyway, and we wouldn\'t know what is |
1593 | channel_permit_all_opens(); | 1640 | permitted except by the client telling us, so we can equally |
1594 | 1641 | well trust the client not to request anything bogus.) */ | |
1595 | /* We stay in this loop until the client requests to execute a shell or a | 1642 | channel_permit_all_opens(); |
1596 | command. */ | 1643 | |
1597 | while (1) | 1644 | /* We stay in this loop until the client requests to execute a |
1598 | { | 1645 | shell or a command. */ |
1599 | int plen, dlen; | 1646 | while (1) { |
1600 | 1647 | int plen, dlen; | |
1601 | /* Get a packet from the client. */ | 1648 | |
1602 | type = packet_read(&plen); | 1649 | /* Get a packet from the client. */ |
1603 | 1650 | type = packet_read(&plen); | |
1604 | /* Process the packet. */ | 1651 | |
1605 | switch (type) | 1652 | /* Process the packet. */ |
1606 | { | 1653 | switch (type) { |
1607 | case SSH_CMSG_REQUEST_COMPRESSION: | 1654 | case SSH_CMSG_REQUEST_COMPRESSION: |
1608 | packet_integrity_check(plen, 4, type); | 1655 | packet_integrity_check(plen, 4, type); |
1609 | compression_level = packet_get_int(); | 1656 | compression_level = packet_get_int(); |
1610 | if (compression_level < 1 || compression_level > 9) | 1657 | if (compression_level < 1 || compression_level > 9) { |
1611 | { | 1658 | packet_send_debug("Received illegal compression level %d.", |
1612 | packet_send_debug("Received illegal compression level %d.", | 1659 | compression_level); |
1613 | compression_level); | 1660 | goto fail; |
1614 | goto fail; | 1661 | } |
1615 | } | 1662 | /* Enable compression after we have responded with SUCCESS. */ |
1616 | /* Enable compression after we have responded with SUCCESS. */ | 1663 | enable_compression_after_reply = 1; |
1617 | enable_compression_after_reply = 1; | 1664 | break; |
1618 | break; | 1665 | |
1619 | 1666 | case SSH_CMSG_REQUEST_PTY: | |
1620 | case SSH_CMSG_REQUEST_PTY: | 1667 | if (no_pty_flag) { |
1621 | if (no_pty_flag) | 1668 | debug("Allocating a pty not permitted for this authentication."); |
1622 | { | 1669 | goto fail; |
1623 | debug("Allocating a pty not permitted for this authentication."); | 1670 | } |
1624 | goto fail; | 1671 | if (have_pty) |
1625 | } | 1672 | packet_disconnect("Protocol error: you already have a pty."); |
1626 | if (have_pty) | 1673 | |
1627 | packet_disconnect("Protocol error: you already have a pty."); | 1674 | debug("Allocating pty."); |
1628 | 1675 | ||
1629 | debug("Allocating pty."); | 1676 | /* Allocate a pty and open it. */ |
1630 | 1677 | if (!pty_allocate(&ptyfd, &ttyfd, ttyname)) { | |
1631 | /* Allocate a pty and open it. */ | 1678 | error("Failed to allocate pty."); |
1632 | if (!pty_allocate(&ptyfd, &ttyfd, ttyname)) | 1679 | goto fail; |
1633 | { | 1680 | } |
1634 | error("Failed to allocate pty."); | 1681 | /* Determine the group to make the owner of the tty. */ |
1635 | goto fail; | 1682 | grp = getgrnam("tty"); |
1636 | } | 1683 | if (grp) { |
1637 | 1684 | tty_gid = grp->gr_gid; | |
1638 | /* Determine the group to make the owner of the tty. */ | 1685 | tty_mode = S_IRUSR | S_IWUSR | S_IWGRP; |
1639 | grp = getgrnam("tty"); | 1686 | } else { |
1640 | if (grp) | 1687 | tty_gid = pw->pw_gid; |
1641 | { | 1688 | tty_mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH; |
1642 | tty_gid = grp->gr_gid; | 1689 | } |
1643 | tty_mode = S_IRUSR|S_IWUSR|S_IWGRP; | 1690 | |
1644 | } | 1691 | /* Change ownership of the tty. */ |
1645 | else | 1692 | if (chown(ttyname, pw->pw_uid, tty_gid) < 0) |
1646 | { | 1693 | fatal("chown(%.100s, %d, %d) failed: %.100s", |
1647 | tty_gid = pw->pw_gid; | 1694 | ttyname, pw->pw_uid, tty_gid, strerror(errno)); |
1648 | tty_mode = S_IRUSR|S_IWUSR|S_IWGRP|S_IWOTH; | 1695 | if (chmod(ttyname, tty_mode) < 0) |
1649 | } | 1696 | fatal("chmod(%.100s, 0%o) failed: %.100s", |
1650 | 1697 | ttyname, tty_mode, strerror(errno)); | |
1651 | /* Change ownership of the tty. */ | 1698 | |
1652 | if (chown(ttyname, pw->pw_uid, tty_gid) < 0) | 1699 | /* Get TERM from the packet. Note that the value may be of arbitrary length. */ |
1653 | fatal("chown(%.100s, %d, %d) failed: %.100s", | 1700 | term = packet_get_string(&dlen); |
1654 | ttyname, pw->pw_uid, tty_gid, strerror(errno)); | 1701 | packet_integrity_check(dlen, strlen(term), type); |
1655 | if (chmod(ttyname, tty_mode) < 0) | 1702 | /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */ |
1656 | fatal("chmod(%.100s, 0%o) failed: %.100s", | 1703 | /* Remaining bytes */ |
1657 | ttyname, tty_mode, strerror(errno)); | 1704 | n_bytes = plen - (4 + dlen + 4 * 4); |
1658 | 1705 | ||
1659 | /* Get TERM from the packet. Note that the value may be of arbitrary | 1706 | if (strcmp(term, "") == 0) |
1660 | length. */ | 1707 | term = NULL; |
1661 | 1708 | ||
1662 | term = packet_get_string(&dlen); | 1709 | /* Get window size from the packet. */ |
1663 | packet_integrity_check(dlen, strlen(term), type); | 1710 | row = packet_get_int(); |
1664 | /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */ | 1711 | col = packet_get_int(); |
1665 | /* Remaining bytes */ | 1712 | xpixel = packet_get_int(); |
1666 | n_bytes = plen - (4 + dlen + 4*4); | 1713 | ypixel = packet_get_int(); |
1667 | 1714 | pty_change_window_size(ptyfd, row, col, xpixel, ypixel); | |
1668 | if (strcmp(term, "") == 0) | 1715 | |
1669 | term = NULL; | 1716 | /* Get tty modes from the packet. */ |
1670 | 1717 | tty_parse_modes(ttyfd, &n_bytes); | |
1671 | /* Get window size from the packet. */ | 1718 | packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type); |
1672 | row = packet_get_int(); | 1719 | |
1673 | col = packet_get_int(); | 1720 | /* Indicate that we now have a pty. */ |
1674 | xpixel = packet_get_int(); | 1721 | have_pty = 1; |
1675 | ypixel = packet_get_int(); | 1722 | break; |
1676 | pty_change_window_size(ptyfd, row, col, xpixel, ypixel); | 1723 | |
1677 | 1724 | case SSH_CMSG_X11_REQUEST_FORWARDING: | |
1678 | /* Get tty modes from the packet. */ | 1725 | if (!options.x11_forwarding) { |
1679 | tty_parse_modes(ttyfd, &n_bytes); | 1726 | packet_send_debug("X11 forwarding disabled in server configuration file."); |
1680 | packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); | 1727 | goto fail; |
1681 | 1728 | } | |
1682 | /* Indicate that we now have a pty. */ | ||
1683 | have_pty = 1; | ||
1684 | break; | ||
1685 | |||
1686 | case SSH_CMSG_X11_REQUEST_FORWARDING: | ||
1687 | if (!options.x11_forwarding) | ||
1688 | { | ||
1689 | packet_send_debug("X11 forwarding disabled in server configuration file."); | ||
1690 | goto fail; | ||
1691 | } | ||
1692 | #ifdef XAUTH_PATH | 1729 | #ifdef XAUTH_PATH |
1693 | if (no_x11_forwarding_flag) | 1730 | if (no_x11_forwarding_flag) { |
1694 | { | 1731 | packet_send_debug("X11 forwarding not permitted for this authentication."); |
1695 | packet_send_debug("X11 forwarding not permitted for this authentication."); | 1732 | goto fail; |
1696 | goto fail; | 1733 | } |
1697 | } | 1734 | debug("Received request for X11 forwarding with auth spoofing."); |
1698 | debug("Received request for X11 forwarding with auth spoofing."); | 1735 | if (display) |
1699 | if (display) | 1736 | packet_disconnect("Protocol error: X11 display already set."); |
1700 | packet_disconnect("Protocol error: X11 display already set."); | 1737 | { |
1701 | { | 1738 | int proto_len, data_len; |
1702 | int proto_len, data_len; | 1739 | proto = packet_get_string(&proto_len); |
1703 | proto = packet_get_string(&proto_len); | 1740 | data = packet_get_string(&data_len); |
1704 | data = packet_get_string(&data_len); | 1741 | packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type); |
1705 | packet_integrity_check(plen, 4+proto_len + 4+data_len + 4, type); | 1742 | } |
1706 | } | 1743 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) |
1707 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) | 1744 | screen = packet_get_int(); |
1708 | screen = packet_get_int(); | 1745 | else |
1709 | else | 1746 | screen = 0; |
1710 | screen = 0; | 1747 | display = x11_create_display_inet(screen); |
1711 | display = x11_create_display_inet(screen); | 1748 | if (!display) |
1712 | if (!display) | 1749 | goto fail; |
1713 | goto fail; | 1750 | |
1714 | 1751 | /* Setup to always have a local .Xauthority. */ | |
1715 | /* Setup to always have a local .Xauthority. */ | 1752 | xauthfile = xmalloc(MAXPATHLEN); |
1716 | xauthfile = xmalloc(MAXPATHLEN); | 1753 | snprintf(xauthfile, MAXPATHLEN, "/tmp/XauthXXXXXX"); |
1717 | snprintf(xauthfile, MAXPATHLEN, "/tmp/XauthXXXXXX"); | 1754 | |
1718 | 1755 | if ((xauthfd = mkstemp(xauthfile)) != -1) { | |
1719 | if ((xauthfd = mkstemp(xauthfile)) != -1) { | 1756 | fchown(xauthfd, pw->pw_uid, pw->pw_gid); |
1720 | fchown(xauthfd, pw->pw_uid, pw->pw_gid); | 1757 | close(xauthfd); |
1721 | close(xauthfd); | 1758 | fatal_add_cleanup(xauthfile_cleanup_proc, NULL); |
1722 | fatal_add_cleanup(xauthfile_cleanup_proc, NULL); | 1759 | } else { |
1723 | } | 1760 | xfree(xauthfile); |
1724 | else { | 1761 | xauthfile = NULL; |
1725 | xfree(xauthfile); | 1762 | } |
1726 | xauthfile = NULL; | 1763 | break; |
1727 | } | ||
1728 | break; | ||
1729 | #else /* XAUTH_PATH */ | 1764 | #else /* XAUTH_PATH */ |
1730 | /* No xauth program; we won't accept forwarding with spoofing. */ | 1765 | packet_send_debug("No xauth program; cannot forward with spoofing."); |
1731 | packet_send_debug("No xauth program; cannot forward with spoofing."); | 1766 | goto fail; |
1732 | goto fail; | ||
1733 | #endif /* XAUTH_PATH */ | 1767 | #endif /* XAUTH_PATH */ |
1734 | 1768 | ||
1735 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: | 1769 | case SSH_CMSG_AGENT_REQUEST_FORWARDING: |
1736 | if (no_agent_forwarding_flag) | 1770 | if (no_agent_forwarding_flag) { |
1737 | { | 1771 | debug("Authentication agent forwarding not permitted for this authentication."); |
1738 | debug("Authentication agent forwarding not permitted for this authentication."); | 1772 | goto fail; |
1739 | goto fail; | 1773 | } |
1740 | } | 1774 | debug("Received authentication agent forwarding request."); |
1741 | debug("Received authentication agent forwarding request."); | 1775 | auth_input_request_forwarding(pw); |
1742 | auth_input_request_forwarding(pw); | 1776 | break; |
1743 | break; | 1777 | |
1744 | 1778 | case SSH_CMSG_PORT_FORWARD_REQUEST: | |
1745 | case SSH_CMSG_PORT_FORWARD_REQUEST: | 1779 | if (no_port_forwarding_flag) { |
1746 | if (no_port_forwarding_flag) | 1780 | debug("Port forwarding not permitted for this authentication."); |
1747 | { | 1781 | goto fail; |
1748 | debug("Port forwarding not permitted for this authentication."); | 1782 | } |
1749 | goto fail; | 1783 | debug("Received TCP/IP port forwarding request."); |
1750 | } | 1784 | channel_input_port_forward_request(pw->pw_uid == 0); |
1751 | debug("Received TCP/IP port forwarding request."); | 1785 | break; |
1752 | channel_input_port_forward_request(pw->pw_uid == 0); | 1786 | |
1753 | break; | 1787 | case SSH_CMSG_MAX_PACKET_SIZE: |
1754 | 1788 | if (packet_set_maxsize(packet_get_int()) < 0) | |
1755 | case SSH_CMSG_MAX_PACKET_SIZE: | 1789 | goto fail; |
1756 | if (packet_set_maxsize(packet_get_int()) < 0) | 1790 | break; |
1757 | goto fail; | 1791 | |
1758 | break; | 1792 | case SSH_CMSG_EXEC_SHELL: |
1759 | 1793 | /* Set interactive/non-interactive mode. */ | |
1760 | case SSH_CMSG_EXEC_SHELL: | 1794 | packet_set_interactive(have_pty || display != NULL, |
1761 | /* Set interactive/non-interactive mode. */ | 1795 | options.keepalives); |
1762 | packet_set_interactive(have_pty || display != NULL, | 1796 | |
1763 | options.keepalives); | 1797 | if (forced_command != NULL) |
1764 | 1798 | goto do_forced_command; | |
1765 | if (forced_command != NULL) | 1799 | debug("Forking shell."); |
1766 | goto do_forced_command; | 1800 | packet_integrity_check(plen, 0, type); |
1767 | debug("Forking shell."); | 1801 | if (have_pty) |
1768 | packet_integrity_check(plen, 0, type); | 1802 | do_exec_pty(NULL, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); |
1769 | if (have_pty) | 1803 | else |
1770 | do_exec_pty(NULL, ptyfd, ttyfd, ttyname, pw, term, display, proto, | 1804 | do_exec_no_pty(NULL, pw, display, proto, data); |
1771 | data); | 1805 | return; |
1772 | else | 1806 | |
1773 | do_exec_no_pty(NULL, pw, display, proto, data); | 1807 | case SSH_CMSG_EXEC_CMD: |
1774 | return; | 1808 | /* Set interactive/non-interactive mode. */ |
1775 | 1809 | packet_set_interactive(have_pty || display != NULL, | |
1776 | case SSH_CMSG_EXEC_CMD: | 1810 | options.keepalives); |
1777 | /* Set interactive/non-interactive mode. */ | 1811 | |
1778 | packet_set_interactive(have_pty || display != NULL, | 1812 | if (forced_command != NULL) |
1779 | options.keepalives); | 1813 | goto do_forced_command; |
1780 | 1814 | /* Get command from the packet. */ | |
1781 | if (forced_command != NULL) | 1815 | { |
1782 | goto do_forced_command; | 1816 | int dlen; |
1783 | /* Get command from the packet. */ | 1817 | command = packet_get_string(&dlen); |
1784 | { | 1818 | debug("Executing command '%.500s'", command); |
1785 | int dlen; | 1819 | packet_integrity_check(plen, 4 + dlen, type); |
1786 | command = packet_get_string(&dlen); | 1820 | } |
1787 | debug("Executing command '%.500s'", command); | 1821 | if (have_pty) |
1788 | packet_integrity_check(plen, 4 + dlen, type); | 1822 | do_exec_pty(command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); |
1789 | } | 1823 | else |
1790 | if (have_pty) | 1824 | do_exec_no_pty(command, pw, display, proto, data); |
1791 | do_exec_pty(command, ptyfd, ttyfd, ttyname, pw, term, display, | 1825 | xfree(command); |
1792 | proto, data); | 1826 | return; |
1793 | else | 1827 | |
1794 | do_exec_no_pty(command, pw, display, proto, data); | 1828 | default: |
1795 | xfree(command); | 1829 | /* Any unknown messages in this phase are ignored, |
1796 | return; | 1830 | and a failure message is returned. */ |
1797 | 1831 | log("Unknown packet type received after authentication: %d", type); | |
1798 | default: | 1832 | goto fail; |
1799 | /* Any unknown messages in this phase are ignored, and a failure | 1833 | } |
1800 | message is returned. */ | ||
1801 | log("Unknown packet type received after authentication: %d", type); | ||
1802 | goto fail; | ||
1803 | } | ||
1804 | 1834 | ||
1805 | /* The request was successfully processed. */ | 1835 | /* The request was successfully processed. */ |
1806 | packet_start(SSH_SMSG_SUCCESS); | 1836 | packet_start(SSH_SMSG_SUCCESS); |
1807 | packet_send(); | 1837 | packet_send(); |
1808 | packet_write_wait(); | 1838 | packet_write_wait(); |
1809 | 1839 | ||
1810 | /* Enable compression now that we have replied if appropriate. */ | 1840 | /* Enable compression now that we have replied if appropriate. */ |
1811 | if (enable_compression_after_reply) | 1841 | if (enable_compression_after_reply) { |
1812 | { | 1842 | enable_compression_after_reply = 0; |
1813 | enable_compression_after_reply = 0; | 1843 | packet_start_compression(compression_level); |
1814 | packet_start_compression(compression_level); | 1844 | } |
1815 | } | 1845 | continue; |
1816 | 1846 | ||
1817 | continue; | 1847 | fail: |
1818 | 1848 | /* The request failed. */ | |
1819 | fail: | 1849 | packet_start(SSH_SMSG_FAILURE); |
1820 | /* The request failed. */ | 1850 | packet_send(); |
1821 | packet_start(SSH_SMSG_FAILURE); | 1851 | packet_write_wait(); |
1822 | packet_send(); | 1852 | continue; |
1823 | packet_write_wait(); | ||
1824 | continue; | ||
1825 | |||
1826 | do_forced_command: | ||
1827 | /* There is a forced command specified for this login. Execute it. */ | ||
1828 | debug("Executing forced command: %.900s", forced_command); | ||
1829 | if (have_pty) | ||
1830 | do_exec_pty(forced_command, ptyfd, ttyfd, ttyname, pw, term, display, | ||
1831 | proto, data); | ||
1832 | else | ||
1833 | do_exec_no_pty(forced_command, pw, display, proto, data); | ||
1834 | return; | ||
1835 | } | ||
1836 | } | ||
1837 | 1853 | ||
1838 | /* This is called to fork and execute a command when we have no tty. This | 1854 | do_forced_command: |
1839 | will call do_child from the child, and server_loop from the parent after | 1855 | /* There is a forced command specified for this login. |
1840 | setting up file descriptors and such. */ | 1856 | Execute it. */ |
1857 | debug("Executing forced command: %.900s", forced_command); | ||
1858 | if (have_pty) | ||
1859 | do_exec_pty(forced_command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data); | ||
1860 | else | ||
1861 | do_exec_no_pty(forced_command, pw, display, proto, data); | ||
1862 | return; | ||
1863 | } | ||
1864 | } | ||
1841 | 1865 | ||
1842 | void do_exec_no_pty(const char *command, struct passwd *pw, | 1866 | /* |
1843 | const char *display, const char *auth_proto, | 1867 | * This is called to fork and execute a command when we have no tty. This |
1844 | const char *auth_data) | 1868 | * will call do_child from the child, and server_loop from the parent after |
1845 | { | 1869 | * setting up file descriptors and such. |
1846 | int pid; | 1870 | */ |
1871 | void | ||
1872 | do_exec_no_pty(const char *command, struct passwd * pw, | ||
1873 | const char *display, const char *auth_proto, | ||
1874 | const char *auth_data) | ||
1875 | { | ||
1876 | int pid; | ||
1847 | 1877 | ||
1848 | #ifdef USE_PIPES | 1878 | #ifdef USE_PIPES |
1849 | int pin[2], pout[2], perr[2]; | 1879 | int pin[2], pout[2], perr[2]; |
1850 | /* Allocate pipes for communicating with the program. */ | 1880 | /* Allocate pipes for communicating with the program. */ |
1851 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) | 1881 | if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0) |
1852 | packet_disconnect("Could not create pipes: %.100s", | 1882 | packet_disconnect("Could not create pipes: %.100s", |
1853 | strerror(errno)); | 1883 | strerror(errno)); |
1854 | #else /* USE_PIPES */ | 1884 | #else /* USE_PIPES */ |
1855 | int inout[2], err[2]; | 1885 | int inout[2], err[2]; |
1856 | /* Uses socket pairs to communicate with the program. */ | 1886 | /* Uses socket pairs to communicate with the program. */ |
1857 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || | 1887 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 || |
1858 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) | 1888 | socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0) |
1859 | packet_disconnect("Could not create socket pairs: %.100s", | 1889 | packet_disconnect("Could not create socket pairs: %.100s", |
1860 | strerror(errno)); | 1890 | strerror(errno)); |
1861 | #endif /* USE_PIPES */ | 1891 | #endif /* USE_PIPES */ |
1862 | |||
1863 | setproctitle("%s@notty", pw->pw_name); | ||
1864 | 1892 | ||
1865 | /* Fork the child. */ | 1893 | setproctitle("%s@notty", pw->pw_name); |
1866 | if ((pid = fork()) == 0) | ||
1867 | { | ||
1868 | /* Child. Reinitialize the log since the pid has changed. */ | ||
1869 | log_init(av0, options.log_level, options.log_facility, log_stderr); | ||
1870 | 1894 | ||
1871 | /* Create a new session and process group since the 4.4BSD setlogin() | 1895 | /* Fork the child. */ |
1872 | affects the entire process group. */ | 1896 | if ((pid = fork()) == 0) { |
1873 | if (setsid() < 0) | 1897 | /* Child. Reinitialize the log since the pid has changed. */ |
1874 | error("setsid failed: %.100s", strerror(errno)); | 1898 | log_init(av0, options.log_level, options.log_facility, log_stderr); |
1899 | |||
1900 | /* Create a new session and process group since the 4.4BSD | ||
1901 | setlogin() affects the entire process group. */ | ||
1902 | if (setsid() < 0) | ||
1903 | error("setsid failed: %.100s", strerror(errno)); | ||
1875 | 1904 | ||
1876 | #ifdef USE_PIPES | 1905 | #ifdef USE_PIPES |
1877 | /* Redirect stdin. We close the parent side of the socket pair, | 1906 | /* Redirect stdin. We close the parent side of the socket |
1878 | and make the child side the standard input. */ | 1907 | pair, and make the child side the standard input. */ |
1879 | close(pin[1]); | 1908 | close(pin[1]); |
1880 | if (dup2(pin[0], 0) < 0) | 1909 | if (dup2(pin[0], 0) < 0) |
1881 | perror("dup2 stdin"); | 1910 | perror("dup2 stdin"); |
1882 | close(pin[0]); | 1911 | close(pin[0]); |
1883 | 1912 | ||
1884 | /* Redirect stdout. */ | 1913 | /* Redirect stdout. */ |
1885 | close(pout[0]); | 1914 | close(pout[0]); |
1886 | if (dup2(pout[1], 1) < 0) | 1915 | if (dup2(pout[1], 1) < 0) |
1887 | perror("dup2 stdout"); | 1916 | perror("dup2 stdout"); |
1888 | close(pout[1]); | 1917 | close(pout[1]); |
1889 | 1918 | ||
1890 | /* Redirect stderr. */ | 1919 | /* Redirect stderr. */ |
1891 | close(perr[0]); | 1920 | close(perr[0]); |
1892 | if (dup2(perr[1], 2) < 0) | 1921 | if (dup2(perr[1], 2) < 0) |
1893 | perror("dup2 stderr"); | 1922 | perror("dup2 stderr"); |
1894 | close(perr[1]); | 1923 | close(perr[1]); |
1895 | #else /* USE_PIPES */ | 1924 | #else /* USE_PIPES */ |
1896 | /* Redirect stdin, stdout, and stderr. Stdin and stdout will use the | 1925 | /* Redirect stdin, stdout, and stderr. Stdin and stdout |
1897 | same socket, as some programs (particularly rdist) seem to depend | 1926 | will use the same socket, as some programs |
1898 | on it. */ | 1927 | (particularly rdist) seem to depend on it. */ |
1899 | close(inout[1]); | 1928 | close(inout[1]); |
1900 | close(err[1]); | 1929 | close(err[1]); |
1901 | if (dup2(inout[0], 0) < 0) /* stdin */ | 1930 | if (dup2(inout[0], 0) < 0) /* stdin */ |
1902 | perror("dup2 stdin"); | 1931 | perror("dup2 stdin"); |
1903 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ | 1932 | if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */ |
1904 | perror("dup2 stdout"); | 1933 | perror("dup2 stdout"); |
1905 | if (dup2(err[0], 2) < 0) /* stderr */ | 1934 | if (dup2(err[0], 2) < 0) /* stderr */ |
1906 | perror("dup2 stderr"); | 1935 | perror("dup2 stderr"); |
1907 | #endif /* USE_PIPES */ | 1936 | #endif /* USE_PIPES */ |
1908 | 1937 | ||
1909 | /* Do processing for the child (exec command etc). */ | 1938 | /* Do processing for the child (exec command etc). */ |
1910 | do_child(command, pw, NULL, display, auth_proto, auth_data, NULL); | 1939 | do_child(command, pw, NULL, display, auth_proto, auth_data, NULL); |
1911 | /*NOTREACHED*/ | 1940 | /* NOTREACHED */ |
1912 | } | 1941 | } |
1913 | if (pid < 0) | 1942 | if (pid < 0) |
1914 | packet_disconnect("fork failed: %.100s", strerror(errno)); | 1943 | packet_disconnect("fork failed: %.100s", strerror(errno)); |
1915 | #ifdef USE_PIPES | 1944 | #ifdef USE_PIPES |
1916 | /* We are the parent. Close the child sides of the pipes. */ | 1945 | /* We are the parent. Close the child sides of the pipes. */ |
1917 | close(pin[0]); | 1946 | close(pin[0]); |
1918 | close(pout[1]); | 1947 | close(pout[1]); |
1919 | close(perr[1]); | 1948 | close(perr[1]); |
1920 | 1949 | ||
1921 | /* Enter the interactive session. */ | 1950 | /* Enter the interactive session. */ |
1922 | server_loop(pid, pin[1], pout[0], perr[0]); | 1951 | server_loop(pid, pin[1], pout[0], perr[0]); |
1923 | /* server_loop has closed pin[1], pout[1], and perr[1]. */ | 1952 | /* server_loop has closed pin[1], pout[1], and perr[1]. */ |
1924 | #else /* USE_PIPES */ | 1953 | #else /* USE_PIPES */ |
1925 | /* We are the parent. Close the child sides of the socket pairs. */ | 1954 | /* We are the parent. Close the child sides of the socket pairs. */ |
1926 | close(inout[0]); | 1955 | close(inout[0]); |
1927 | close(err[0]); | 1956 | close(err[0]); |
1928 | 1957 | ||
1929 | /* Enter the interactive session. Note: server_loop must be able to handle | 1958 | /* Enter the interactive session. Note: server_loop must be able |
1930 | the case that fdin and fdout are the same. */ | 1959 | to handle the case that fdin and fdout are the same. */ |
1931 | server_loop(pid, inout[1], inout[1], err[1]); | 1960 | server_loop(pid, inout[1], inout[1], err[1]); |
1932 | /* server_loop has closed inout[1] and err[1]. */ | 1961 | /* server_loop has closed inout[1] and err[1]. */ |
1933 | #endif /* USE_PIPES */ | 1962 | #endif /* USE_PIPES */ |
1934 | } | 1963 | } |
1935 | 1964 | ||
1936 | struct pty_cleanup_context | 1965 | struct pty_cleanup_context { |
1937 | { | 1966 | const char *ttyname; |
1938 | const char *ttyname; | 1967 | int pid; |
1939 | int pid; | ||
1940 | }; | 1968 | }; |
1941 | 1969 | ||
1942 | /* Function to perform cleanup if we get aborted abnormally (e.g., due to a | 1970 | /* |
1943 | dropped connection). */ | 1971 | * Function to perform cleanup if we get aborted abnormally (e.g., due to a |
1944 | 1972 | * dropped connection). | |
1945 | void pty_cleanup_proc(void *context) | 1973 | */ |
1974 | void | ||
1975 | pty_cleanup_proc(void *context) | ||
1946 | { | 1976 | { |
1947 | struct pty_cleanup_context *cu = context; | 1977 | struct pty_cleanup_context *cu = context; |
1948 | 1978 | ||
1949 | debug("pty_cleanup_proc called"); | 1979 | debug("pty_cleanup_proc called"); |
1950 | 1980 | ||
1951 | /* Record that the user has logged out. */ | 1981 | /* Record that the user has logged out. */ |
1952 | record_logout(cu->pid, cu->ttyname); | 1982 | record_logout(cu->pid, cu->ttyname); |
1953 | 1983 | ||
1954 | /* Release the pseudo-tty. */ | 1984 | /* Release the pseudo-tty. */ |
1955 | pty_release(cu->ttyname); | 1985 | pty_release(cu->ttyname); |
1956 | } | 1986 | } |
1957 | 1987 | ||
1958 | /* This is called to fork and execute a command when we have a tty. This | 1988 | /* |
1959 | will call do_child from the child, and server_loop from the parent after | 1989 | * This is called to fork and execute a command when we have a tty. This |
1960 | setting up file descriptors, controlling tty, updating wtmp, utmp, | 1990 | * will call do_child from the child, and server_loop from the parent after |
1961 | lastlog, and other such operations. */ | 1991 | * setting up file descriptors, controlling tty, updating wtmp, utmp, |
1962 | 1992 | * lastlog, and other such operations. | |
1963 | void do_exec_pty(const char *command, int ptyfd, int ttyfd, | 1993 | */ |
1964 | const char *ttyname, struct passwd *pw, const char *term, | 1994 | void |
1965 | const char *display, const char *auth_proto, | 1995 | do_exec_pty(const char *command, int ptyfd, int ttyfd, |
1966 | const char *auth_data) | 1996 | const char *ttyname, struct passwd * pw, const char *term, |
1997 | const char *display, const char *auth_proto, | ||
1998 | const char *auth_data) | ||
1967 | { | 1999 | { |
1968 | int pid, fdout; | 2000 | int pid, fdout; |
1969 | const char *hostname; | 2001 | const char *hostname; |
1970 | time_t last_login_time; | 2002 | time_t last_login_time; |
1971 | char buf[100], *time_string; | 2003 | char buf[100], *time_string; |
1972 | FILE *f; | 2004 | FILE *f; |
1973 | char line[256]; | 2005 | char line[256]; |
1974 | struct stat st; | 2006 | struct stat st; |
1975 | int quiet_login; | 2007 | int quiet_login; |
1976 | struct sockaddr_in from; | 2008 | struct sockaddr_in from; |
1977 | int fromlen; | 2009 | int fromlen; |
1978 | struct pty_cleanup_context cleanup_context; | 2010 | struct pty_cleanup_context cleanup_context; |
1979 | 2011 | ||
1980 | /* Get remote host name. */ | 2012 | /* Get remote host name. */ |
1981 | hostname = get_canonical_hostname(); | 2013 | hostname = get_canonical_hostname(); |
1982 | 2014 | ||
1983 | /* Get the time when the user last logged in. Buf will be set to contain | 2015 | /* Get the time when the user last logged in. Buf will be set to |
1984 | the hostname the last login was from. */ | 2016 | contain the hostname the last login was from. */ |
1985 | if(!options.use_login) { | 2017 | if (!options.use_login) { |
1986 | last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, | 2018 | last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, |
1987 | buf, sizeof(buf)); | 2019 | buf, sizeof(buf)); |
1988 | } | ||
1989 | |||
1990 | setproctitle("%s@%s", pw->pw_name, strrchr(ttyname, '/') + 1); | ||
1991 | |||
1992 | /* Fork the child. */ | ||
1993 | if ((pid = fork()) == 0) | ||
1994 | { | ||
1995 | pid = getpid(); | ||
1996 | |||
1997 | /* Child. Reinitialize the log because the pid has changed. */ | ||
1998 | log_init(av0, options.log_level, options.log_facility, log_stderr); | ||
1999 | |||
2000 | /* Close the master side of the pseudo tty. */ | ||
2001 | close(ptyfd); | ||
2002 | |||
2003 | /* Make the pseudo tty our controlling tty. */ | ||
2004 | pty_make_controlling_tty(&ttyfd, ttyname); | ||
2005 | |||
2006 | /* Redirect stdin from the pseudo tty. */ | ||
2007 | if (dup2(ttyfd, fileno(stdin)) < 0) | ||
2008 | error("dup2 stdin failed: %.100s", strerror(errno)); | ||
2009 | |||
2010 | /* Redirect stdout to the pseudo tty. */ | ||
2011 | if (dup2(ttyfd, fileno(stdout)) < 0) | ||
2012 | error("dup2 stdin failed: %.100s", strerror(errno)); | ||
2013 | |||
2014 | /* Redirect stderr to the pseudo tty. */ | ||
2015 | if (dup2(ttyfd, fileno(stderr)) < 0) | ||
2016 | error("dup2 stdin failed: %.100s", strerror(errno)); | ||
2017 | |||
2018 | /* Close the extra descriptor for the pseudo tty. */ | ||
2019 | close(ttyfd); | ||
2020 | |||
2021 | /* Get IP address of client. This is needed because we want to record | ||
2022 | where the user logged in from. If the connection is not a socket, | ||
2023 | let the ip address be 0.0.0.0. */ | ||
2024 | memset(&from, 0, sizeof(from)); | ||
2025 | if (packet_get_connection_in() == packet_get_connection_out()) | ||
2026 | { | ||
2027 | fromlen = sizeof(from); | ||
2028 | if (getpeername(packet_get_connection_in(), | ||
2029 | (struct sockaddr *)&from, &fromlen) < 0) { | ||
2030 | debug("getpeername: %.100s", strerror(errno)); | ||
2031 | fatal_cleanup(); | ||
2032 | } | ||
2033 | } | 2020 | } |
2021 | setproctitle("%s@%s", pw->pw_name, strrchr(ttyname, '/') + 1); | ||
2022 | |||
2023 | /* Fork the child. */ | ||
2024 | if ((pid = fork()) == 0) { | ||
2025 | pid = getpid(); | ||
2026 | |||
2027 | /* Child. Reinitialize the log because the pid has | ||
2028 | changed. */ | ||
2029 | log_init(av0, options.log_level, options.log_facility, log_stderr); | ||
2030 | |||
2031 | /* Close the master side of the pseudo tty. */ | ||
2032 | close(ptyfd); | ||
2033 | |||
2034 | /* Make the pseudo tty our controlling tty. */ | ||
2035 | pty_make_controlling_tty(&ttyfd, ttyname); | ||
2036 | |||
2037 | /* Redirect stdin from the pseudo tty. */ | ||
2038 | if (dup2(ttyfd, fileno(stdin)) < 0) | ||
2039 | error("dup2 stdin failed: %.100s", strerror(errno)); | ||
2040 | |||
2041 | /* Redirect stdout to the pseudo tty. */ | ||
2042 | if (dup2(ttyfd, fileno(stdout)) < 0) | ||
2043 | error("dup2 stdin failed: %.100s", strerror(errno)); | ||
2044 | |||
2045 | /* Redirect stderr to the pseudo tty. */ | ||
2046 | if (dup2(ttyfd, fileno(stderr)) < 0) | ||
2047 | error("dup2 stdin failed: %.100s", strerror(errno)); | ||
2048 | |||
2049 | /* Close the extra descriptor for the pseudo tty. */ | ||
2050 | close(ttyfd); | ||
2051 | |||
2052 | /* Get IP address of client. This is needed because we | ||
2053 | want to record where the user logged in from. If the | ||
2054 | connection is not a socket, let the ip address be 0.0.0.0. */ | ||
2055 | memset(&from, 0, sizeof(from)); | ||
2056 | if (packet_get_connection_in() == packet_get_connection_out()) { | ||
2057 | fromlen = sizeof(from); | ||
2058 | if (getpeername(packet_get_connection_in(), | ||
2059 | (struct sockaddr *) & from, &fromlen) < 0) { | ||
2060 | debug("getpeername: %.100s", strerror(errno)); | ||
2061 | fatal_cleanup(); | ||
2062 | } | ||
2063 | } | ||
2064 | /* Record that there was a login on that terminal. */ | ||
2065 | record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname, | ||
2066 | &from); | ||
2034 | 2067 | ||
2035 | /* Record that there was a login on that terminal. */ | 2068 | /* Check if .hushlogin exists. */ |
2036 | record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname, | 2069 | snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir); |
2037 | &from); | 2070 | quiet_login = stat(line, &st) >= 0; |
2038 | |||
2039 | /* Check if .hushlogin exists. */ | ||
2040 | snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir); | ||
2041 | quiet_login = stat(line, &st) >= 0; | ||
2042 | 2071 | ||
2043 | #ifdef HAVE_LIBPAM | 2072 | #ifdef HAVE_LIBPAM |
2044 | /* output the results of the pamconv() */ | 2073 | /* output the results of the pamconv() */ |
2045 | if (!quiet_login && pamconv_msg != NULL) | 2074 | if (!quiet_login && pamconv_msg != NULL) |
2046 | fprintf(stderr, pamconv_msg); | 2075 | fprintf(stderr, pamconv_msg); |
2047 | #endif | 2076 | #endif |
2048 | |||
2049 | /* If the user has logged in before, display the time of last login. | ||
2050 | However, don't display anything extra if a command has been | ||
2051 | specified (so that ssh can be used to execute commands on a remote | ||
2052 | machine without users knowing they are going to another machine). | ||
2053 | Login(1) will do this for us as well, so check if login(1) is used */ | ||
2054 | if (command == NULL && last_login_time != 0 && !quiet_login && | ||
2055 | !options.use_login) | ||
2056 | { | ||
2057 | /* Convert the date to a string. */ | ||
2058 | time_string = ctime(&last_login_time); | ||
2059 | /* Remove the trailing newline. */ | ||
2060 | if (strchr(time_string, '\n')) | ||
2061 | *strchr(time_string, '\n') = 0; | ||
2062 | /* Display the last login time. Host if displayed if known. */ | ||
2063 | if (strcmp(buf, "") == 0) | ||
2064 | printf("Last login: %s\r\n", time_string); | ||
2065 | else | ||
2066 | printf("Last login: %s from %s\r\n", time_string, buf); | ||
2067 | } | ||
2068 | 2077 | ||
2069 | /* Print /etc/motd unless a command was specified or printing it was | 2078 | /* If the user has logged in before, display the time of |
2070 | disabled in server options or login(1) will be used. Note that | 2079 | last login. However, don't display anything extra if a |
2071 | some machines appear to print it in /etc/profile or similar. */ | 2080 | command has been specified (so that ssh can be used to |
2072 | if (command == NULL && options.print_motd && !quiet_login && | 2081 | execute commands on a remote machine without users |
2073 | !options.use_login) | 2082 | knowing they are going to another machine). Login(1) |
2074 | { | 2083 | will do this for us as well, so check if login(1) is used */ |
2075 | /* Print /etc/motd if it exists. */ | 2084 | if (command == NULL && last_login_time != 0 && !quiet_login && |
2076 | f = fopen("/etc/motd", "r"); | 2085 | !options.use_login) { |
2077 | if (f) | 2086 | /* Convert the date to a string. */ |
2078 | { | 2087 | time_string = ctime(&last_login_time); |
2079 | while (fgets(line, sizeof(line), f)) | 2088 | /* Remove the trailing newline. */ |
2080 | fputs(line, stdout); | 2089 | if (strchr(time_string, '\n')) |
2081 | fclose(f); | 2090 | *strchr(time_string, '\n') = 0; |
2082 | } | 2091 | /* Display the last login time. Host if displayed |
2092 | if known. */ | ||
2093 | if (strcmp(buf, "") == 0) | ||
2094 | printf("Last login: %s\r\n", time_string); | ||
2095 | else | ||
2096 | printf("Last login: %s from %s\r\n", time_string, buf); | ||
2097 | } | ||
2098 | /* Print /etc/motd unless a command was specified or | ||
2099 | printing it was disabled in server options or login(1) | ||
2100 | will be used. Note that some machines appear to print | ||
2101 | it in /etc/profile or similar. */ | ||
2102 | if (command == NULL && options.print_motd && !quiet_login && | ||
2103 | !options.use_login) { | ||
2104 | /* Print /etc/motd if it exists. */ | ||
2105 | f = fopen("/etc/motd", "r"); | ||
2106 | if (f) { | ||
2107 | while (fgets(line, sizeof(line), f)) | ||
2108 | fputs(line, stdout); | ||
2109 | fclose(f); | ||
2110 | } | ||
2111 | } | ||
2112 | /* Do common processing for the child, such as execing the command. */ | ||
2113 | do_child(command, pw, term, display, auth_proto, auth_data, ttyname); | ||
2114 | /* NOTREACHED */ | ||
2083 | } | 2115 | } |
2084 | 2116 | if (pid < 0) | |
2085 | /* Do common processing for the child, such as execing the command. */ | 2117 | packet_disconnect("fork failed: %.100s", strerror(errno)); |
2086 | do_child(command, pw, term, display, auth_proto, auth_data, ttyname); | 2118 | /* Parent. Close the slave side of the pseudo tty. */ |
2087 | /*NOTREACHED*/ | 2119 | close(ttyfd); |
2088 | } | 2120 | |
2089 | if (pid < 0) | 2121 | /* Create another descriptor of the pty master side for use as the |
2090 | packet_disconnect("fork failed: %.100s", strerror(errno)); | 2122 | standard input. We could use the original descriptor, but this |
2091 | /* Parent. Close the slave side of the pseudo tty. */ | 2123 | simplifies code in server_loop. The descriptor is bidirectional. */ |
2092 | close(ttyfd); | 2124 | fdout = dup(ptyfd); |
2093 | 2125 | if (fdout < 0) | |
2094 | /* Create another descriptor of the pty master side for use as the standard | 2126 | packet_disconnect("dup failed: %.100s", strerror(errno)); |
2095 | input. We could use the original descriptor, but this simplifies code | 2127 | |
2096 | in server_loop. The descriptor is bidirectional. */ | 2128 | /* Add a cleanup function to clear the utmp entry and record logout |
2097 | fdout = dup(ptyfd); | 2129 | time in case we call fatal() (e.g., the connection gets closed). */ |
2098 | if (fdout < 0) | 2130 | cleanup_context.pid = pid; |
2099 | packet_disconnect("dup failed: %.100s", strerror(errno)); | 2131 | cleanup_context.ttyname = ttyname; |
2100 | 2132 | fatal_add_cleanup(pty_cleanup_proc, (void *) &cleanup_context); | |
2101 | /* Add a cleanup function to clear the utmp entry and record logout time | 2133 | |
2102 | in case we call fatal() (e.g., the connection gets closed). */ | 2134 | /* Enter interactive session. */ |
2103 | cleanup_context.pid = pid; | 2135 | server_loop(pid, ptyfd, fdout, -1); |
2104 | cleanup_context.ttyname = ttyname; | 2136 | /* server_loop has not closed ptyfd and fdout. */ |
2105 | fatal_add_cleanup(pty_cleanup_proc, (void *)&cleanup_context); | 2137 | |
2106 | 2138 | /* Cancel the cleanup function. */ | |
2107 | /* Enter interactive session. */ | 2139 | fatal_remove_cleanup(pty_cleanup_proc, (void *) &cleanup_context); |
2108 | server_loop(pid, ptyfd, fdout, -1); | 2140 | |
2109 | /* server_loop has not closed ptyfd and fdout. */ | 2141 | /* Record that the user has logged out. */ |
2110 | 2142 | record_logout(pid, ttyname); | |
2111 | /* Cancel the cleanup function. */ | 2143 | |
2112 | fatal_remove_cleanup(pty_cleanup_proc, (void *)&cleanup_context); | 2144 | /* Release the pseudo-tty. */ |
2113 | 2145 | pty_release(ttyname); | |
2114 | /* Record that the user has logged out. */ | 2146 | |
2115 | record_logout(pid, ttyname); | 2147 | /* Close the server side of the socket pairs. We must do this |
2116 | 2148 | after the pty cleanup, so that another process doesn't get this | |
2117 | /* Release the pseudo-tty. */ | 2149 | pty while we're still cleaning up. */ |
2118 | pty_release(ttyname); | 2150 | close(ptyfd); |
2119 | 2151 | close(fdout); | |
2120 | /* Close the server side of the socket pairs. We must do this after the | ||
2121 | pty cleanup, so that another process doesn't get this pty while we're | ||
2122 | still cleaning up. */ | ||
2123 | close(ptyfd); | ||
2124 | close(fdout); | ||
2125 | } | 2152 | } |
2126 | 2153 | ||
2127 | /* Sets the value of the given variable in the environment. If the variable | 2154 | /* |
2128 | already exists, its value is overriden. */ | 2155 | * Sets the value of the given variable in the environment. If the variable |
2129 | 2156 | * already exists, its value is overriden. | |
2130 | void child_set_env(char ***envp, unsigned int *envsizep, const char *name, | 2157 | */ |
2131 | const char *value) | 2158 | void |
2159 | child_set_env(char ***envp, unsigned int *envsizep, const char *name, | ||
2160 | const char *value) | ||
2132 | { | 2161 | { |
2133 | unsigned int i, namelen; | 2162 | unsigned int i, namelen; |
2134 | char **env; | 2163 | char **env; |
2135 | 2164 | ||
2136 | /* Find the slot where the value should be stored. If the variable already | 2165 | /* Find the slot where the value should be stored. If the |
2137 | exists, we reuse the slot; otherwise we append a new slot at the end | 2166 | variable already exists, we reuse the slot; otherwise we append |
2138 | of the array, expanding if necessary. */ | 2167 | a new slot at the end of the array, expanding if necessary. */ |
2139 | env = *envp; | 2168 | env = *envp; |
2140 | namelen = strlen(name); | 2169 | namelen = strlen(name); |
2141 | for (i = 0; env[i]; i++) | 2170 | for (i = 0; env[i]; i++) |
2142 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') | 2171 | if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') |
2143 | break; | 2172 | break; |
2144 | if (env[i]) | 2173 | if (env[i]) { |
2145 | { | 2174 | /* Name already exists. Reuse the slot. */ |
2146 | /* Name already exists. Reuse the slot. */ | 2175 | xfree(env[i]); |
2147 | xfree(env[i]); | 2176 | } else { |
2148 | } | 2177 | /* New variable. Expand the array if necessary. */ |
2149 | else | 2178 | if (i >= (*envsizep) - 1) { |
2150 | { | 2179 | (*envsizep) += 50; |
2151 | /* New variable. Expand the array if necessary. */ | 2180 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); |
2152 | if (i >= (*envsizep) - 1) | 2181 | } |
2153 | { | 2182 | /* Need to set the NULL pointer at end of array beyond the new slot. */ |
2154 | (*envsizep) += 50; | 2183 | env[i + 1] = NULL; |
2155 | env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *)); | ||
2156 | } | 2184 | } |
2157 | 2185 | ||
2158 | /* Need to set the NULL pointer at end of array beyond the new | 2186 | /* Allocate space and format the variable in the appropriate slot. */ |
2159 | slot. */ | 2187 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); |
2160 | env[i + 1] = NULL; | 2188 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); |
2161 | } | ||
2162 | |||
2163 | /* Allocate space and format the variable in the appropriate slot. */ | ||
2164 | env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); | ||
2165 | snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); | ||
2166 | } | 2189 | } |
2167 | 2190 | ||
2168 | /* Reads environment variables from the given file and adds/overrides them | 2191 | /* |
2169 | into the environment. If the file does not exist, this does nothing. | 2192 | * Reads environment variables from the given file and adds/overrides them |
2170 | Otherwise, it must consist of empty lines, comments (line starts with '#') | 2193 | * into the environment. If the file does not exist, this does nothing. |
2171 | and assignments of the form name=value. No other forms are allowed. */ | 2194 | * Otherwise, it must consist of empty lines, comments (line starts with '#') |
2172 | 2195 | * and assignments of the form name=value. No other forms are allowed. | |
2173 | void read_environment_file(char ***env, unsigned int *envsize, | 2196 | */ |
2174 | const char *filename) | 2197 | void |
2198 | read_environment_file(char ***env, unsigned int *envsize, | ||
2199 | const char *filename) | ||
2175 | { | 2200 | { |
2176 | FILE *f; | 2201 | FILE *f; |
2177 | char buf[4096]; | 2202 | char buf[4096]; |
2178 | char *cp, *value; | 2203 | char *cp, *value; |
2179 | 2204 | ||
2180 | /* Open the environment file. */ | 2205 | /* Open the environment file. */ |
2181 | f = fopen(filename, "r"); | 2206 | f = fopen(filename, "r"); |
2182 | if (!f) | 2207 | if (!f) |
2183 | return; /* Not found. */ | 2208 | return; |
2184 | 2209 | ||
2185 | /* Process each line. */ | 2210 | /* Process each line. */ |
2186 | while (fgets(buf, sizeof(buf), f)) | 2211 | while (fgets(buf, sizeof(buf), f)) { |
2187 | { | 2212 | /* Skip leading whitespace. */ |
2188 | /* Skip leading whitespace. */ | 2213 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++); |
2189 | for (cp = buf; *cp == ' ' || *cp == '\t'; cp++) | 2214 | |
2190 | ; | 2215 | /* Ignore empty and comment lines. */ |
2191 | 2216 | if (!*cp || *cp == '#' || *cp == '\n') | |
2192 | /* Ignore empty and comment lines. */ | 2217 | continue; |
2193 | if (!*cp || *cp == '#' || *cp == '\n') | 2218 | |
2194 | continue; | 2219 | /* Remove newline. */ |
2195 | 2220 | if (strchr(cp, '\n')) | |
2196 | /* Remove newline. */ | 2221 | *strchr(cp, '\n') = '\0'; |
2197 | if (strchr(cp, '\n')) | 2222 | |
2198 | *strchr(cp, '\n') = '\0'; | 2223 | /* Find the equals sign. Its lack indicates badly |
2199 | 2224 | formatted line. */ | |
2200 | /* Find the equals sign. Its lack indicates badly formatted line. */ | 2225 | value = strchr(cp, '='); |
2201 | value = strchr(cp, '='); | 2226 | if (value == NULL) { |
2202 | if (value == NULL) | 2227 | fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf); |
2203 | { | 2228 | continue; |
2204 | fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf); | 2229 | } |
2205 | continue; | 2230 | /* Replace the equals sign by nul, and advance value to |
2206 | } | 2231 | the value string. */ |
2232 | *value = '\0'; | ||
2233 | value++; | ||
2207 | 2234 | ||
2208 | /* Replace the equals sign by nul, and advance value to the value | 2235 | /* Set the value in environment. */ |
2209 | string. */ | 2236 | child_set_env(env, envsize, cp, value); |
2210 | *value = '\0'; | 2237 | } |
2211 | value++; | ||
2212 | 2238 | ||
2213 | /* Set the value in environment. */ | 2239 | fclose(f); |
2214 | child_set_env(env, envsize, cp, value); | ||
2215 | } | ||
2216 | |||
2217 | fclose(f); | ||
2218 | } | 2240 | } |
2219 | 2241 | ||
2220 | /* Performs common processing for the child, such as setting up the | 2242 | /* |
2221 | environment, closing extra file descriptors, setting the user and group | 2243 | * Performs common processing for the child, such as setting up the |
2222 | ids, and executing the command or shell. */ | 2244 | * environment, closing extra file descriptors, setting the user and group |
2223 | 2245 | * ids, and executing the command or shell. | |
2224 | void do_child(const char *command, struct passwd *pw, const char *term, | 2246 | */ |
2225 | const char *display, const char *auth_proto, | 2247 | void |
2226 | const char *auth_data, const char *ttyname) | 2248 | do_child(const char *command, struct passwd * pw, const char *term, |
2249 | const char *display, const char *auth_proto, | ||
2250 | const char *auth_data, const char *ttyname) | ||
2227 | { | 2251 | { |
2228 | const char *shell, *cp = NULL; | 2252 | const char *shell, *cp = NULL; |
2229 | char buf[256]; | 2253 | char buf[256]; |
2230 | FILE *f; | 2254 | FILE *f; |
2231 | unsigned int envsize, i; | 2255 | unsigned int envsize, i; |
2232 | char **env; | 2256 | char **env; |
2233 | extern char **environ; | 2257 | extern char **environ; |
2234 | struct stat st; | 2258 | struct stat st; |
2235 | char *argv[10]; | 2259 | char *argv[10]; |
2236 | 2260 | ||
2237 | #ifndef HAVE_LIBPAM /* pam_nologin handles this */ | 2261 | #ifndef HAVE_LIBPAM /* pam_nologin handles this */ |
2238 | /* Check /etc/nologin. */ | 2262 | /* Check /etc/nologin. */ |
2239 | f = fopen("/etc/nologin", "r"); | 2263 | f = fopen("/etc/nologin", "r"); |
2240 | if (f) | 2264 | if (f) { |
2241 | { /* /etc/nologin exists. Print its contents and exit. */ | 2265 | /* /etc/nologin exists. Print its contents and exit. */ |
2242 | while (fgets(buf, sizeof(buf), f)) | 2266 | while (fgets(buf, sizeof(buf), f)) |
2243 | fputs(buf, stderr); | 2267 | fputs(buf, stderr); |
2244 | fclose(f); | 2268 | fclose(f); |
2245 | if (pw->pw_uid != 0) | 2269 | if (pw->pw_uid != 0) |
2246 | exit(254); | 2270 | exit(254); |
2247 | } | 2271 | } |
2248 | #endif /* HAVE_LIBPAM */ | 2272 | #endif /* HAVE_LIBPAM */ |
2249 | 2273 | ||
2250 | #ifdef HAVE_SETLOGIN | 2274 | #ifdef HAVE_SETLOGIN |
2251 | /* Set login name in the kernel. */ | 2275 | /* Set login name in the kernel. */ |
2252 | if (setlogin(pw->pw_name) < 0) | 2276 | if (setlogin(pw->pw_name) < 0) |
2253 | error("setlogin failed: %s", strerror(errno)); | 2277 | error("setlogin failed: %s", strerror(errno)); |
2254 | #endif /* HAVE_SETLOGIN */ | 2278 | #endif /* HAVE_SETLOGIN */ |
2255 | 2279 | ||
2256 | /* Set uid, gid, and groups. */ | 2280 | /* Set uid, gid, and groups. */ |
2257 | /* Login(1) does this as well, and it needs uid 0 for the "-h" switch, | 2281 | /* Login(1) does this as well, and it needs uid 0 for the "-h" |
2258 | so we let login(1) to this for us. */ | 2282 | switch, so we let login(1) to this for us. */ |
2259 | if(!options.use_login) { | 2283 | if (!options.use_login) { |
2260 | if (getuid() == 0 || geteuid() == 0) | 2284 | if (getuid() == 0 || geteuid() == 0) { |
2261 | { | 2285 | if (setgid(pw->pw_gid) < 0) { |
2262 | if (setgid(pw->pw_gid) < 0) | 2286 | perror("setgid"); |
2263 | { | 2287 | exit(1); |
2264 | perror("setgid"); | 2288 | } |
2265 | exit(1); | 2289 | /* Initialize the group list. */ |
2266 | } | 2290 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) { |
2267 | /* Initialize the group list. */ | 2291 | perror("initgroups"); |
2268 | if (initgroups(pw->pw_name, pw->pw_gid) < 0) | 2292 | exit(1); |
2269 | { | 2293 | } |
2270 | perror("initgroups"); | 2294 | endgrent(); |
2271 | exit(1); | 2295 | |
2272 | } | 2296 | /* Permanently switch to the desired uid. */ |
2273 | endgrent(); | 2297 | permanently_set_uid(pw->pw_uid); |
2274 | 2298 | } | |
2275 | /* Permanently switch to the desired uid. */ | 2299 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) |
2276 | permanently_set_uid(pw->pw_uid); | 2300 | fatal("Failed to set uids to %d.", (int) pw->pw_uid); |
2277 | } | 2301 | } |
2278 | 2302 | /* Get the shell from the password data. An empty shell field is | |
2279 | if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) | 2303 | legal, and means /bin/sh. */ |
2280 | fatal("Failed to set uids to %d.", (int)pw->pw_uid); | 2304 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; |
2281 | } | ||
2282 | |||
2283 | /* Get the shell from the password data. An empty shell field is legal, | ||
2284 | and means /bin/sh. */ | ||
2285 | shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; | ||
2286 | 2305 | ||
2287 | #ifdef AFS | 2306 | #ifdef AFS |
2288 | /* Try to get AFS tokens for the local cell. */ | 2307 | /* Try to get AFS tokens for the local cell. */ |
2289 | if (k_hasafs()) { | 2308 | if (k_hasafs()) { |
2290 | char cell[64]; | 2309 | char cell[64]; |
2291 | 2310 | ||
2292 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) | 2311 | if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) |
2293 | krb_afslog(cell, 0); | 2312 | krb_afslog(cell, 0); |
2294 | 2313 | ||
2295 | krb_afslog(0, 0); | 2314 | krb_afslog(0, 0); |
2296 | } | 2315 | } |
2297 | #endif /* AFS */ | 2316 | #endif /* AFS */ |
2298 | 2317 | ||
2299 | /* Initialize the environment. In the first part we allocate space for | 2318 | /* Initialize the environment. In the first part we allocate |
2300 | all environment variables. */ | 2319 | space for all environment variables. */ |
2301 | envsize = 100; | 2320 | envsize = 100; |
2302 | env = xmalloc(envsize * sizeof(char *)); | 2321 | env = xmalloc(envsize * sizeof(char *)); |
2303 | env[0] = NULL; | 2322 | env[0] = NULL; |
2304 | 2323 | ||
2305 | if(!options.use_login) { | 2324 | if (!options.use_login) { |
2306 | /* Set basic environment. */ | 2325 | /* Set basic environment. */ |
2307 | child_set_env(&env, &envsize, "USER", pw->pw_name); | 2326 | child_set_env(&env, &envsize, "USER", pw->pw_name); |
2308 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); | 2327 | child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); |
2309 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); | 2328 | child_set_env(&env, &envsize, "HOME", pw->pw_dir); |
2310 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); | 2329 | child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); |
2311 | 2330 | ||
2312 | snprintf(buf, sizeof buf, "%.200s/%.50s", | 2331 | snprintf(buf, sizeof buf, "%.200s/%.50s", |
2313 | _PATH_MAILDIR, pw->pw_name); | 2332 | _PATH_MAILDIR, pw->pw_name); |
2314 | child_set_env(&env, &envsize, "MAIL", buf); | 2333 | child_set_env(&env, &envsize, "MAIL", buf); |
2315 | 2334 | ||
2316 | /* Normal systems set SHELL by default. */ | 2335 | /* Normal systems set SHELL by default. */ |
2317 | child_set_env(&env, &envsize, "SHELL", shell); | 2336 | child_set_env(&env, &envsize, "SHELL", shell); |
2318 | } | 2337 | } |
2319 | 2338 | /* Let it inherit timezone if we have one. */ | |
2320 | /* Let it inherit timezone if we have one. */ | 2339 | if (getenv("TZ")) |
2321 | if (getenv("TZ")) | 2340 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); |
2322 | child_set_env(&env, &envsize, "TZ", getenv("TZ")); | 2341 | |
2323 | 2342 | /* Set custom environment options from RSA authentication. */ | |
2324 | /* Set custom environment options from RSA authentication. */ | 2343 | while (custom_environment) { |
2325 | while (custom_environment) | 2344 | struct envstring *ce = custom_environment; |
2326 | { | 2345 | char *s = ce->s; |
2327 | struct envstring *ce = custom_environment; | 2346 | int i; |
2328 | char *s = ce->s; | 2347 | for (i = 0; s[i] != '=' && s[i]; i++); |
2329 | int i; | 2348 | if (s[i] == '=') { |
2330 | for (i = 0; s[i] != '=' && s[i]; i++) | 2349 | s[i] = 0; |
2331 | ; | 2350 | child_set_env(&env, &envsize, s, s + i + 1); |
2332 | if (s[i] == '=') | 2351 | } |
2333 | { | 2352 | custom_environment = ce->next; |
2334 | s[i] = 0; | 2353 | xfree(ce->s); |
2335 | child_set_env(&env, &envsize, s, s + i + 1); | 2354 | xfree(ce); |
2336 | } | 2355 | } |
2337 | custom_environment = ce->next; | ||
2338 | xfree(ce->s); | ||
2339 | xfree(ce); | ||
2340 | } | ||
2341 | 2356 | ||
2342 | /* Set SSH_CLIENT. */ | 2357 | /* Set SSH_CLIENT. */ |
2343 | snprintf(buf, sizeof buf, "%.50s %d %d", | 2358 | snprintf(buf, sizeof buf, "%.50s %d %d", |
2344 | get_remote_ipaddr(), get_remote_port(), options.port); | 2359 | get_remote_ipaddr(), get_remote_port(), options.port); |
2345 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); | 2360 | child_set_env(&env, &envsize, "SSH_CLIENT", buf); |
2346 | 2361 | ||
2347 | /* Set SSH_TTY if we have a pty. */ | 2362 | /* Set SSH_TTY if we have a pty. */ |
2348 | if (ttyname) | 2363 | if (ttyname) |
2349 | child_set_env(&env, &envsize, "SSH_TTY", ttyname); | 2364 | child_set_env(&env, &envsize, "SSH_TTY", ttyname); |
2350 | 2365 | ||
2351 | /* Set TERM if we have a pty. */ | 2366 | /* Set TERM if we have a pty. */ |
2352 | if (term) | 2367 | if (term) |
2353 | child_set_env(&env, &envsize, "TERM", term); | 2368 | child_set_env(&env, &envsize, "TERM", term); |
2354 | 2369 | ||
2355 | /* Set DISPLAY if we have one. */ | 2370 | /* Set DISPLAY if we have one. */ |
2356 | if (display) | 2371 | if (display) |
2357 | child_set_env(&env, &envsize, "DISPLAY", display); | 2372 | child_set_env(&env, &envsize, "DISPLAY", display); |
2358 | 2373 | ||
2359 | #ifdef KRB4 | 2374 | #ifdef KRB4 |
2360 | { | 2375 | { |
2361 | extern char *ticket; | 2376 | extern char *ticket; |
2362 | 2377 | ||
2363 | if (ticket) | 2378 | if (ticket) |
2364 | child_set_env(&env, &envsize, "KRBTKFILE", ticket); | 2379 | child_set_env(&env, &envsize, "KRBTKFILE", ticket); |
2365 | } | 2380 | } |
2366 | #endif /* KRB4 */ | 2381 | #endif /* KRB4 */ |
2367 | 2382 | ||
2368 | #ifdef HAVE_LIBPAM | 2383 | #ifdef HAVE_LIBPAM |
2369 | /* Pull in any environment variables that may have been set by PAM. */ | 2384 | /* Pull in any environment variables that may have been set by PAM. */ |
2370 | { | 2385 | { |
2371 | char *equal_sign, var_name[256], var_val[256]; | 2386 | char *equals, var_name[512], var_val[512]; |
2372 | long this_var; | 2387 | char **pam_env = pam_getenvlist((pam_handle_t *)pamh); |
2373 | char **pam_env = pam_getenvlist((pam_handle_t *)pamh); | 2388 | int i; |
2374 | for(this_var = 0; pam_env && pam_env[this_var]; this_var++) | 2389 | for(i = 0; pam_env && pam_env[i]; i++) { |
2375 | { | 2390 | equals = strstr(pam_env[i], "="); |
2376 | if(strlen(pam_env[this_var]) < (sizeof(var_name) - 1)) | 2391 | if ((strlen(pam_env[i]) < (sizeof(var_name) - 1)) && (equals != NULL)) |
2377 | if((equal_sign = strstr(pam_env[this_var], "=")) != NULL) | 2392 | { |
2378 | { | 2393 | memset(var_name, '\0', sizeof(var_name)); |
2379 | memset(var_name, 0, sizeof(var_name)); | 2394 | memset(var_val, '\0', sizeof(var_val)); |
2380 | memset(var_val, 0, sizeof(var_val)); | 2395 | strncpy(var_name, pam_env[i], equals - pam_env[i]); |
2381 | strncpy(var_name, pam_env[this_var], | 2396 | strcpy(var_val, equals + 1); |
2382 | equal_sign - pam_env[this_var]); | 2397 | child_set_env(&env, &envsize, var_name, var_val); |
2383 | strcpy(var_val, equal_sign + 1); | 2398 | } |
2384 | child_set_env(&env, &envsize, var_name, var_val); | 2399 | } |
2385 | } | 2400 | } |
2386 | } | ||
2387 | } | ||
2388 | #endif /* HAVE_LIBPAM */ | 2401 | #endif /* HAVE_LIBPAM */ |
2389 | 2402 | ||
2390 | /* Set XAUTHORITY to always be a local file. */ | 2403 | /* Set XAUTHORITY to always be a local file. */ |
2391 | if (xauthfile) | 2404 | if (xauthfile) |
2392 | child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); | 2405 | child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); |
2393 | 2406 | ||
2394 | /* Set variable for forwarded authentication connection, if we have one. */ | 2407 | /* Set variable for forwarded authentication connection, if we |
2395 | if (auth_get_socket_name() != NULL) | 2408 | have one. */ |
2396 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, | 2409 | if (auth_get_socket_name() != NULL) |
2397 | auth_get_socket_name()); | 2410 | child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, |
2398 | 2411 | auth_get_socket_name()); | |
2399 | /* Read $HOME/.ssh/environment. */ | 2412 | |
2400 | if(!options.use_login) { | 2413 | /* Read $HOME/.ssh/environment. */ |
2401 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir); | 2414 | if (!options.use_login) { |
2402 | read_environment_file(&env, &envsize, buf); | 2415 | snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir); |
2403 | } | 2416 | read_environment_file(&env, &envsize, buf); |
2404 | 2417 | } | |
2405 | /* If debugging, dump the environment to stderr. */ | 2418 | /* If debugging, dump the environment to stderr. */ |
2406 | if (debug_flag) | 2419 | if (debug_flag) { |
2407 | { | 2420 | fprintf(stderr, "Environment:\n"); |
2408 | fprintf(stderr, "Environment:\n"); | 2421 | for (i = 0; env[i]; i++) |
2409 | for (i = 0; env[i]; i++) | 2422 | fprintf(stderr, " %.200s\n", env[i]); |
2410 | fprintf(stderr, " %.200s\n", env[i]); | 2423 | } |
2411 | } | 2424 | /* Close the connection descriptors; note that this is the child, |
2412 | 2425 | and the server will still have the socket open, and it is | |
2413 | /* Close the connection descriptors; note that this is the child, and the | 2426 | important that we do not shutdown it. Note that the |
2414 | server will still have the socket open, and it is important that we | 2427 | descriptors cannot be closed before building the environment, |
2415 | do not shutdown it. Note that the descriptors cannot be closed before | 2428 | as we call get_remote_ipaddr there. */ |
2416 | building the environment, as we call get_remote_ipaddr there. */ | 2429 | if (packet_get_connection_in() == packet_get_connection_out()) |
2417 | if (packet_get_connection_in() == packet_get_connection_out()) | 2430 | close(packet_get_connection_in()); |
2418 | close(packet_get_connection_in()); | 2431 | else { |
2419 | else | 2432 | close(packet_get_connection_in()); |
2420 | { | 2433 | close(packet_get_connection_out()); |
2421 | close(packet_get_connection_in()); | 2434 | } |
2422 | close(packet_get_connection_out()); | 2435 | /* Close all descriptors related to channels. They will still |
2423 | } | 2436 | remain open in the parent. */ |
2424 | /* Close all descriptors related to channels. They will still remain | 2437 | channel_close_all(); |
2425 | open in the parent. */ | 2438 | |
2426 | channel_close_all(); | 2439 | /* Close any extra file descriptors. Note that there may still be |
2427 | 2440 | descriptors left by system functions. They will be closed | |
2428 | /* Close any extra file descriptors. Note that there may still be | 2441 | later. */ |
2429 | descriptors left by system functions. They will be closed later. */ | 2442 | endpwent(); |
2430 | endpwent(); | 2443 | endhostent(); |
2431 | endhostent(); | 2444 | |
2432 | 2445 | /* Close any extra open file descriptors so that we don\'t have | |
2433 | /* Close any extra open file descriptors so that we don\'t have them | 2446 | them hanging around in clients. Note that we want to do this |
2434 | hanging around in clients. Note that we want to do this after | 2447 | after initgroups, because at least on Solaris 2.3 it leaves |
2435 | initgroups, because at least on Solaris 2.3 it leaves file descriptors | 2448 | file descriptors open. */ |
2436 | open. */ | 2449 | for (i = 3; i < 64; i++) |
2437 | for (i = 3; i < 64; i++) | 2450 | close(i); |
2438 | close(i); | 2451 | |
2439 | 2452 | /* Change current directory to the user\'s home directory. */ | |
2440 | /* Change current directory to the user\'s home directory. */ | 2453 | if (chdir(pw->pw_dir) < 0) |
2441 | if (chdir(pw->pw_dir) < 0) | 2454 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", |
2442 | fprintf(stderr, "Could not chdir to home directory %s: %s\n", | 2455 | pw->pw_dir, strerror(errno)); |
2443 | pw->pw_dir, strerror(errno)); | 2456 | |
2444 | 2457 | /* Must take new environment into use so that .ssh/rc, /etc/sshrc | |
2445 | /* Must take new environment into use so that .ssh/rc, /etc/sshrc and | 2458 | and xauth are run in the proper environment. */ |
2446 | xauth are run in the proper environment. */ | 2459 | environ = env; |
2447 | environ = env; | 2460 | |
2448 | 2461 | /* Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found | |
2449 | /* Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first | 2462 | first in this order). */ |
2450 | in this order). */ | 2463 | if (!options.use_login) { |
2451 | if(!options.use_login) { | 2464 | if (stat(SSH_USER_RC, &st) >= 0) { |
2452 | if (stat(SSH_USER_RC, &st) >= 0) | 2465 | if (debug_flag) |
2453 | { | 2466 | fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC); |
2454 | if (debug_flag) | 2467 | |
2455 | fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC); | 2468 | f = popen("/bin/sh " SSH_USER_RC, "w"); |
2456 | 2469 | if (f) { | |
2457 | f = popen("/bin/sh " SSH_USER_RC, "w"); | 2470 | if (auth_proto != NULL && auth_data != NULL) |
2458 | if (f) | 2471 | fprintf(f, "%s %s\n", auth_proto, auth_data); |
2459 | { | 2472 | pclose(f); |
2460 | if (auth_proto != NULL && auth_data != NULL) | 2473 | } else |
2461 | fprintf(f, "%s %s\n", auth_proto, auth_data); | 2474 | fprintf(stderr, "Could not run %s\n", SSH_USER_RC); |
2462 | pclose(f); | 2475 | } else if (stat(SSH_SYSTEM_RC, &st) >= 0) { |
2463 | } | 2476 | if (debug_flag) |
2464 | else | 2477 | fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC); |
2465 | fprintf(stderr, "Could not run %s\n", SSH_USER_RC); | 2478 | |
2466 | } | 2479 | f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); |
2467 | else | 2480 | if (f) { |
2468 | if (stat(SSH_SYSTEM_RC, &st) >= 0) | 2481 | if (auth_proto != NULL && auth_data != NULL) |
2469 | { | 2482 | fprintf(f, "%s %s\n", auth_proto, auth_data); |
2470 | if (debug_flag) | 2483 | pclose(f); |
2471 | fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC); | 2484 | } else |
2472 | 2485 | fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); | |
2473 | f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); | 2486 | } |
2474 | if (f) | ||
2475 | { | ||
2476 | if (auth_proto != NULL && auth_data != NULL) | ||
2477 | fprintf(f, "%s %s\n", auth_proto, auth_data); | ||
2478 | pclose(f); | ||
2479 | } | ||
2480 | else | ||
2481 | fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); | ||
2482 | } | ||
2483 | #ifdef XAUTH_PATH | 2487 | #ifdef XAUTH_PATH |
2484 | else | 2488 | else { |
2485 | { | 2489 | /* Add authority data to .Xauthority if |
2486 | /* Add authority data to .Xauthority if appropriate. */ | 2490 | appropriate. */ |
2487 | if (auth_proto != NULL && auth_data != NULL) | 2491 | if (auth_proto != NULL && auth_data != NULL) { |
2488 | { | 2492 | if (debug_flag) |
2489 | if (debug_flag) | 2493 | fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n", |
2490 | fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n", | 2494 | XAUTH_PATH, display, auth_proto, auth_data); |
2491 | XAUTH_PATH, display, auth_proto, auth_data); | 2495 | |
2492 | 2496 | f = popen(XAUTH_PATH " -q -", "w"); | |
2493 | f = popen(XAUTH_PATH " -q -", "w"); | 2497 | if (f) { |
2494 | if (f) | 2498 | fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data); |
2495 | { | 2499 | fclose(f); |
2496 | fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data); | 2500 | } else |
2497 | fclose(f); | 2501 | fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH); |
2498 | } | 2502 | } |
2499 | else | 2503 | } |
2500 | fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH); | ||
2501 | } | ||
2502 | } | ||
2503 | #endif /* XAUTH_PATH */ | 2504 | #endif /* XAUTH_PATH */ |
2504 | 2505 | ||
2505 | /* Get the last component of the shell name. */ | 2506 | /* Get the last component of the shell name. */ |
2506 | cp = strrchr(shell, '/'); | 2507 | cp = strrchr(shell, '/'); |
2507 | if (cp) | 2508 | if (cp) |
2508 | cp++; | 2509 | cp++; |
2509 | else | 2510 | else |
2510 | cp = shell; | 2511 | cp = shell; |
2511 | } | 2512 | } |
2512 | 2513 | /* If we have no command, execute the shell. In this case, the | |
2513 | /* If we have no command, execute the shell. In this case, the shell name | 2514 | shell name to be passed in argv[0] is preceded by '-' to |
2514 | to be passed in argv[0] is preceded by '-' to indicate that this is | 2515 | indicate that this is a login shell. */ |
2515 | a login shell. */ | 2516 | if (!command) { |
2516 | if (!command) | 2517 | if (!options.use_login) { |
2517 | { | 2518 | char buf[256]; |
2518 | if(!options.use_login) { | 2519 | |
2519 | char buf[256]; | 2520 | /* Check for mail if we have a tty and it was |
2520 | 2521 | enabled in server options. */ | |
2521 | /* Check for mail if we have a tty and it was enabled in server options. */ | 2522 | if (ttyname && options.check_mail) { |
2522 | if (ttyname && options.check_mail) { | 2523 | char *mailbox; |
2523 | char *mailbox; | 2524 | struct stat mailstat; |
2524 | struct stat mailstat; | 2525 | mailbox = getenv("MAIL"); |
2525 | mailbox = getenv("MAIL"); | 2526 | if (mailbox != NULL) { |
2526 | if(mailbox != NULL) { | 2527 | if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0) |
2527 | if(stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0) { | 2528 | printf("No mail.\n"); |
2528 | printf("No mail.\n"); | 2529 | else if (mailstat.st_mtime < mailstat.st_atime) |
2529 | } else if(mailstat.st_mtime < mailstat.st_atime) { | 2530 | printf("You have mail.\n"); |
2530 | printf("You have mail.\n"); | 2531 | else |
2531 | } else { | 2532 | printf("You have new mail.\n"); |
2532 | printf("You have new mail.\n"); | 2533 | } |
2533 | } | 2534 | } |
2534 | } | 2535 | /* Start the shell. Set initial character to '-'. */ |
2535 | } | 2536 | buf[0] = '-'; |
2536 | /* Start the shell. Set initial character to '-'. */ | 2537 | strncpy(buf + 1, cp, sizeof(buf) - 1); |
2537 | buf[0] = '-'; | 2538 | buf[sizeof(buf) - 1] = 0; |
2538 | strncpy(buf + 1, cp, sizeof(buf) - 1); | 2539 | |
2539 | buf[sizeof(buf) - 1] = 0; | 2540 | /* Execute the shell. */ |
2540 | /* Execute the shell. */ | 2541 | argv[0] = buf; |
2541 | argv[0] = buf; | 2542 | argv[1] = NULL; |
2542 | argv[1] = NULL; | 2543 | execve(shell, argv, env); |
2543 | execve(shell, argv, env); | 2544 | |
2544 | /* Executing the shell failed. */ | 2545 | /* Executing the shell failed. */ |
2545 | perror(shell); | 2546 | perror(shell); |
2546 | exit(1); | 2547 | exit(1); |
2547 | 2548 | ||
2548 | } else { | 2549 | } else { |
2549 | /* Launch login(1). */ | 2550 | /* Launch login(1). */ |
2550 | 2551 | ||
2551 | execl(LOGIN_PROGRAM, "login", "-h", get_remote_ipaddr(), "-p", "-f", "--", pw->pw_name, NULL); | 2552 | execl(LOGIN_PROGRAM, "login", "-h", get_remote_ipaddr(), |
2552 | 2553 | "-p", "-f", "--", pw->pw_name, NULL); | |
2553 | /* Login couldn't be executed, die. */ | 2554 | |
2554 | 2555 | /* Login couldn't be executed, die. */ | |
2555 | perror("login"); | 2556 | |
2556 | exit(1); | 2557 | perror("login"); |
2557 | } | 2558 | exit(1); |
2558 | } | 2559 | } |
2559 | 2560 | } | |
2560 | /* Execute the command using the user's shell. This uses the -c option | 2561 | /* Execute the command using the user's shell. This uses the -c |
2561 | to execute the command. */ | 2562 | option to execute the command. */ |
2562 | argv[0] = (char *)cp; | 2563 | argv[0] = (char *) cp; |
2563 | argv[1] = "-c"; | 2564 | argv[1] = "-c"; |
2564 | argv[2] = (char *)command; | 2565 | argv[2] = (char *) command; |
2565 | argv[3] = NULL; | 2566 | argv[3] = NULL; |
2566 | execve(shell, argv, env); | 2567 | execve(shell, argv, env); |
2567 | perror(shell); | 2568 | perror(shell); |
2568 | exit(1); | 2569 | exit(1); |
2569 | } | 2570 | } |