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ff7ec503 | 1 | /* $OpenBSD: sshconnect.c,v 1.200 2006/10/10 10:12:45 markus Exp $ */ |
3c0ef626 | 2 | /* |
3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
5 | * All rights reserved | |
6 | * Code to connect to a remote host, and to perform the client side of the | |
7 | * login (authentication) dialog. | |
8 | * | |
9 | * As far as I am concerned, the code I have written for this software | |
10 | * can be used freely for any purpose. Any derived versions of this | |
11 | * software must be clearly marked as such, and if the derived work is | |
12 | * incompatible with the protocol description in the RFC file, it must be | |
13 | * called by a name other than "ssh" or "Secure Shell". | |
14 | */ | |
15 | ||
16 | #include "includes.h" | |
3c0ef626 | 17 | |
9108f8d9 | 18 | #include <sys/types.h> |
19 | #include <sys/wait.h> | |
20 | #include <sys/stat.h> | |
21 | #include <sys/socket.h> | |
22 | #ifdef HAVE_SYS_TIME_H | |
23 | # include <sys/time.h> | |
24 | #endif | |
25 | ||
26 | #include <netinet/in.h> | |
27 | #include <arpa/inet.h> | |
28 | ||
29 | #include <ctype.h> | |
30 | #include <errno.h> | |
31 | #include <netdb.h> | |
32 | #ifdef HAVE_PATHS_H | |
33 | #include <paths.h> | |
34 | #endif | |
35 | #include <pwd.h> | |
36 | #include <stdarg.h> | |
37 | #include <stdio.h> | |
38 | #include <stdlib.h> | |
39 | #include <string.h> | |
40 | #include <unistd.h> | |
3c0ef626 | 41 | |
3c0ef626 | 42 | #include "xmalloc.h" |
9108f8d9 | 43 | #include "key.h" |
44 | #include "hostfile.h" | |
45 | #include "ssh.h" | |
3c0ef626 | 46 | #include "rsa.h" |
47 | #include "buffer.h" | |
48 | #include "packet.h" | |
49 | #include "uidswap.h" | |
50 | #include "compat.h" | |
51 | #include "key.h" | |
52 | #include "sshconnect.h" | |
53 | #include "hostfile.h" | |
54 | #include "log.h" | |
55 | #include "readconf.h" | |
56 | #include "atomicio.h" | |
57 | #include "misc.h" | |
0fff78ff | 58 | #include "dns.h" |
9108f8d9 | 59 | #include "version.h" |
0fff78ff | 60 | |
3c0ef626 | 61 | char *client_version_string = NULL; |
62 | char *server_version_string = NULL; | |
63 | ||
2c06c99b | 64 | static int matching_host_key_dns = 0; |
0fff78ff | 65 | |
f5799ae1 | 66 | /* import */ |
3c0ef626 | 67 | extern Options options; |
68 | extern char *__progname; | |
f5799ae1 | 69 | extern uid_t original_real_uid; |
70 | extern uid_t original_effective_uid; | |
41b2f314 | 71 | extern pid_t proxy_command_pid; |
3c0ef626 | 72 | |
73 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ | |
74 | #define INET6_ADDRSTRLEN 46 | |
75 | #endif | |
76 | ||
41b2f314 | 77 | static int show_other_keys(const char *, Key *); |
cdd66111 | 78 | static void warn_changed_key(Key *); |
3c0ef626 | 79 | |
80 | /* | |
81 | * Connect to the given ssh server using a proxy command. | |
82 | */ | |
83 | static int | |
f5799ae1 | 84 | ssh_proxy_connect(const char *host, u_short port, const char *proxy_command) |
3c0ef626 | 85 | { |
665a873d | 86 | char *command_string, *tmp; |
3c0ef626 | 87 | int pin[2], pout[2]; |
88 | pid_t pid; | |
89 | char strport[NI_MAXSERV]; | |
90 | ||
91 | /* Convert the port number into a string. */ | |
92 | snprintf(strport, sizeof strport, "%hu", port); | |
93 | ||
41b2f314 | 94 | /* |
95 | * Build the final command string in the buffer by making the | |
96 | * appropriate substitutions to the given proxy command. | |
97 | * | |
cdd66111 | 98 | * Use "exec" to avoid "sh -c" processes on some platforms |
41b2f314 | 99 | * (e.g. Solaris) |
100 | */ | |
9108f8d9 | 101 | xasprintf(&tmp, "exec %s", proxy_command); |
665a873d | 102 | command_string = percent_expand(tmp, "h", host, |
103 | "p", strport, (char *)NULL); | |
104 | xfree(tmp); | |
3c0ef626 | 105 | |
106 | /* Create pipes for communicating with the proxy. */ | |
107 | if (pipe(pin) < 0 || pipe(pout) < 0) | |
108 | fatal("Could not create pipes to communicate with the proxy: %.100s", | |
e9a17296 | 109 | strerror(errno)); |
3c0ef626 | 110 | |
111 | debug("Executing proxy command: %.500s", command_string); | |
112 | ||
113 | /* Fork and execute the proxy command. */ | |
114 | if ((pid = fork()) == 0) { | |
115 | char *argv[10]; | |
116 | ||
117 | /* Child. Permanently give up superuser privileges. */ | |
9108f8d9 | 118 | permanently_drop_suid(original_real_uid); |
3c0ef626 | 119 | |
120 | /* Redirect stdin and stdout. */ | |
121 | close(pin[1]); | |
122 | if (pin[0] != 0) { | |
123 | if (dup2(pin[0], 0) < 0) | |
124 | perror("dup2 stdin"); | |
125 | close(pin[0]); | |
126 | } | |
127 | close(pout[0]); | |
128 | if (dup2(pout[1], 1) < 0) | |
129 | perror("dup2 stdout"); | |
130 | /* Cannot be 1 because pin allocated two descriptors. */ | |
131 | close(pout[1]); | |
132 | ||
133 | /* Stderr is left as it is so that error messages get | |
134 | printed on the user's terminal. */ | |
135 | argv[0] = _PATH_BSHELL; | |
136 | argv[1] = "-c"; | |
137 | argv[2] = command_string; | |
138 | argv[3] = NULL; | |
139 | ||
140 | /* Execute the proxy command. Note that we gave up any | |
141 | extra privileges above. */ | |
142 | execv(argv[0], argv); | |
143 | perror(argv[0]); | |
144 | exit(1); | |
145 | } | |
146 | /* Parent. */ | |
147 | if (pid < 0) | |
148 | fatal("fork failed: %.100s", strerror(errno)); | |
41b2f314 | 149 | else |
150 | proxy_command_pid = pid; /* save pid to clean up later */ | |
3c0ef626 | 151 | |
152 | /* Close child side of the descriptors. */ | |
153 | close(pin[0]); | |
154 | close(pout[1]); | |
155 | ||
156 | /* Free the command name. */ | |
665a873d | 157 | xfree(command_string); |
3c0ef626 | 158 | |
159 | /* Set the connection file descriptors. */ | |
160 | packet_set_connection(pout[0], pin[1]); | |
161 | ||
162 | /* Indicate OK return */ | |
163 | return 0; | |
164 | } | |
165 | ||
166 | /* | |
167 | * Creates a (possibly privileged) socket for use as the ssh connection. | |
168 | */ | |
169 | static int | |
0fff78ff | 170 | ssh_create_socket(int privileged, struct addrinfo *ai) |
3c0ef626 | 171 | { |
172 | int sock, gaierr; | |
173 | struct addrinfo hints, *res; | |
174 | ||
175 | /* | |
176 | * If we are running as root and want to connect to a privileged | |
177 | * port, bind our own socket to a privileged port. | |
178 | */ | |
179 | if (privileged) { | |
180 | int p = IPPORT_RESERVED - 1; | |
f5799ae1 | 181 | PRIV_START; |
0fff78ff | 182 | sock = rresvport_af(&p, ai->ai_family); |
f5799ae1 | 183 | PRIV_END; |
3c0ef626 | 184 | if (sock < 0) |
0fff78ff | 185 | error("rresvport: af=%d %.100s", ai->ai_family, |
186 | strerror(errno)); | |
3c0ef626 | 187 | else |
188 | debug("Allocated local port %d.", p); | |
189 | return sock; | |
190 | } | |
0fff78ff | 191 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3c0ef626 | 192 | if (sock < 0) |
193 | error("socket: %.100s", strerror(errno)); | |
3c0ef626 | 194 | |
195 | /* Bind the socket to an alternative local IP address */ | |
196 | if (options.bind_address == NULL) | |
197 | return sock; | |
198 | ||
199 | memset(&hints, 0, sizeof(hints)); | |
0fff78ff | 200 | hints.ai_family = ai->ai_family; |
201 | hints.ai_socktype = ai->ai_socktype; | |
202 | hints.ai_protocol = ai->ai_protocol; | |
3c0ef626 | 203 | hints.ai_flags = AI_PASSIVE; |
204 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); | |
205 | if (gaierr) { | |
206 | error("getaddrinfo: %s: %s", options.bind_address, | |
207 | gai_strerror(gaierr)); | |
208 | close(sock); | |
209 | return -1; | |
210 | } | |
211 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { | |
212 | error("bind: %s: %s", options.bind_address, strerror(errno)); | |
213 | close(sock); | |
214 | freeaddrinfo(res); | |
215 | return -1; | |
216 | } | |
217 | freeaddrinfo(res); | |
218 | return sock; | |
219 | } | |
220 | ||
0fff78ff | 221 | static int |
222 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, | |
223 | socklen_t addrlen, int timeout) | |
224 | { | |
225 | fd_set *fdset; | |
226 | struct timeval tv; | |
227 | socklen_t optlen; | |
9108f8d9 | 228 | int optval, rc, result = -1; |
0fff78ff | 229 | |
230 | if (timeout <= 0) | |
231 | return (connect(sockfd, serv_addr, addrlen)); | |
232 | ||
cdd66111 | 233 | set_nonblock(sockfd); |
0fff78ff | 234 | rc = connect(sockfd, serv_addr, addrlen); |
cdd66111 | 235 | if (rc == 0) { |
236 | unset_nonblock(sockfd); | |
0fff78ff | 237 | return (0); |
cdd66111 | 238 | } |
0fff78ff | 239 | if (errno != EINPROGRESS) |
240 | return (-1); | |
241 | ||
9108f8d9 | 242 | fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS), |
243 | sizeof(fd_mask)); | |
0fff78ff | 244 | FD_SET(sockfd, fdset); |
245 | tv.tv_sec = timeout; | |
246 | tv.tv_usec = 0; | |
247 | ||
dec6d9fe | 248 | for (;;) { |
0fff78ff | 249 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
250 | if (rc != -1 || errno != EINTR) | |
251 | break; | |
252 | } | |
253 | ||
dec6d9fe | 254 | switch (rc) { |
0fff78ff | 255 | case 0: |
256 | /* Timed out */ | |
257 | errno = ETIMEDOUT; | |
258 | break; | |
259 | case -1: | |
260 | /* Select error */ | |
cdd66111 | 261 | debug("select: %s", strerror(errno)); |
0fff78ff | 262 | break; |
263 | case 1: | |
264 | /* Completed or failed */ | |
265 | optval = 0; | |
266 | optlen = sizeof(optval); | |
cdd66111 | 267 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
acc3d05e | 268 | &optlen) == -1) { |
cdd66111 | 269 | debug("getsockopt: %s", strerror(errno)); |
0fff78ff | 270 | break; |
acc3d05e | 271 | } |
0fff78ff | 272 | if (optval != 0) { |
273 | errno = optval; | |
274 | break; | |
275 | } | |
276 | result = 0; | |
cdd66111 | 277 | unset_nonblock(sockfd); |
0fff78ff | 278 | break; |
279 | default: | |
280 | /* Should not occur */ | |
281 | fatal("Bogus return (%d) from select()", rc); | |
282 | } | |
283 | ||
284 | xfree(fdset); | |
285 | return (result); | |
286 | } | |
287 | ||
3c0ef626 | 288 | /* |
289 | * Opens a TCP/IP connection to the remote server on the given host. | |
290 | * The address of the remote host will be returned in hostaddr. | |
f5799ae1 | 291 | * If port is 0, the default port will be used. If needpriv is true, |
3c0ef626 | 292 | * a privileged port will be allocated to make the connection. |
f5799ae1 | 293 | * This requires super-user privileges if needpriv is true. |
3c0ef626 | 294 | * Connection_attempts specifies the maximum number of tries (one per |
295 | * second). If proxy_command is non-NULL, it specifies the command (with %h | |
296 | * and %p substituted for host and port, respectively) to use to contact | |
297 | * the daemon. | |
3c0ef626 | 298 | */ |
299 | int | |
300 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, | |
301 | u_short port, int family, int connection_attempts, | |
f5799ae1 | 302 | int needpriv, const char *proxy_command) |
3c0ef626 | 303 | { |
304 | int gaierr; | |
305 | int on = 1; | |
306 | int sock = -1, attempt; | |
307 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
308 | struct addrinfo hints, *ai, *aitop; | |
3c0ef626 | 309 | |
6a9b3198 | 310 | debug2("ssh_connect: needpriv %d", needpriv); |
3c0ef626 | 311 | |
3c0ef626 | 312 | /* If a proxy command is given, connect using it. */ |
313 | if (proxy_command != NULL) | |
f5799ae1 | 314 | return ssh_proxy_connect(host, port, proxy_command); |
3c0ef626 | 315 | |
316 | /* No proxy command. */ | |
317 | ||
318 | memset(&hints, 0, sizeof(hints)); | |
319 | hints.ai_family = family; | |
320 | hints.ai_socktype = SOCK_STREAM; | |
680cee3b | 321 | snprintf(strport, sizeof strport, "%u", port); |
3c0ef626 | 322 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
323 | fatal("%s: %.100s: %s", __progname, host, | |
324 | gai_strerror(gaierr)); | |
325 | ||
9108f8d9 | 326 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
ff7ec503 | 327 | if (attempt > 0) { |
328 | /* Sleep a moment before retrying. */ | |
329 | sleep(1); | |
3c0ef626 | 330 | debug("Trying again..."); |
ff7ec503 | 331 | } |
9108f8d9 | 332 | /* |
333 | * Loop through addresses for this host, and try each one in | |
334 | * sequence until the connection succeeds. | |
335 | */ | |
3c0ef626 | 336 | for (ai = aitop; ai; ai = ai->ai_next) { |
337 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
338 | continue; | |
339 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
340 | ntop, sizeof(ntop), strport, sizeof(strport), | |
341 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
342 | error("ssh_connect: getnameinfo failed"); | |
343 | continue; | |
344 | } | |
345 | debug("Connecting to %.200s [%.100s] port %s.", | |
346 | host, ntop, strport); | |
347 | ||
348 | /* Create a socket for connecting. */ | |
0fff78ff | 349 | sock = ssh_create_socket(needpriv, ai); |
3c0ef626 | 350 | if (sock < 0) |
351 | /* Any error is already output */ | |
352 | continue; | |
353 | ||
0fff78ff | 354 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
355 | options.connection_timeout) >= 0) { | |
3c0ef626 | 356 | /* Successful connection. */ |
357 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); | |
3c0ef626 | 358 | break; |
359 | } else { | |
41b2f314 | 360 | debug("connect to address %s port %s: %s", |
361 | ntop, strport, strerror(errno)); | |
3c0ef626 | 362 | close(sock); |
9108f8d9 | 363 | sock = -1; |
3c0ef626 | 364 | } |
365 | } | |
9108f8d9 | 366 | if (sock != -1) |
3c0ef626 | 367 | break; /* Successful connection. */ |
3c0ef626 | 368 | } |
369 | ||
370 | freeaddrinfo(aitop); | |
371 | ||
372 | /* Return failure if we didn't get a successful connection. */ | |
9108f8d9 | 373 | if (sock == -1) { |
996d5e62 | 374 | error("ssh: connect to host %s port %s: %s", |
41b2f314 | 375 | host, strport, strerror(errno)); |
996d5e62 | 376 | return (-1); |
41b2f314 | 377 | } |
3c0ef626 | 378 | |
379 | debug("Connection established."); | |
380 | ||
cdd66111 | 381 | /* Set SO_KEEPALIVE if requested. */ |
382 | if (options.tcp_keep_alive && | |
3c0ef626 | 383 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
384 | sizeof(on)) < 0) | |
385 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
386 | ||
387 | /* Set the connection. */ | |
388 | packet_set_connection(sock, sock); | |
389 | ||
390 | return 0; | |
391 | } | |
392 | ||
393 | /* | |
394 | * Waits for the server identification string, and sends our own | |
395 | * identification string. | |
396 | */ | |
397 | static void | |
398 | ssh_exchange_identification(void) | |
399 | { | |
400 | char buf[256], remote_version[256]; /* must be same size! */ | |
665a873d | 401 | int remote_major, remote_minor, mismatch; |
3c0ef626 | 402 | int connection_in = packet_get_connection_in(); |
403 | int connection_out = packet_get_connection_out(); | |
404 | int minor1 = PROTOCOL_MINOR_1; | |
9108f8d9 | 405 | u_int i, n; |
3c0ef626 | 406 | |
665a873d | 407 | /* Read other side's version identification. */ |
9108f8d9 | 408 | for (n = 0;;) { |
3c0ef626 | 409 | for (i = 0; i < sizeof(buf) - 1; i++) { |
665a873d | 410 | size_t len = atomicio(read, connection_in, &buf[i], 1); |
411 | ||
412 | if (len != 1 && errno == EPIPE) | |
3c0ef626 | 413 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
665a873d | 414 | else if (len != 1) |
415 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); | |
3c0ef626 | 416 | if (buf[i] == '\r') { |
417 | buf[i] = '\n'; | |
418 | buf[i + 1] = 0; | |
419 | continue; /**XXX wait for \n */ | |
420 | } | |
421 | if (buf[i] == '\n') { | |
422 | buf[i + 1] = 0; | |
423 | break; | |
424 | } | |
9108f8d9 | 425 | if (++n > 65536) |
426 | fatal("ssh_exchange_identification: No banner received"); | |
3c0ef626 | 427 | } |
428 | buf[sizeof(buf) - 1] = 0; | |
429 | if (strncmp(buf, "SSH-", 4) == 0) | |
430 | break; | |
431 | debug("ssh_exchange_identification: %s", buf); | |
432 | } | |
433 | server_version_string = xstrdup(buf); | |
434 | ||
435 | /* | |
436 | * Check that the versions match. In future this might accept | |
437 | * several versions and set appropriate flags to handle them. | |
438 | */ | |
439 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", | |
440 | &remote_major, &remote_minor, remote_version) != 3) | |
441 | fatal("Bad remote protocol version identification: '%.100s'", buf); | |
442 | debug("Remote protocol version %d.%d, remote software version %.100s", | |
e9a17296 | 443 | remote_major, remote_minor, remote_version); |
3c0ef626 | 444 | |
445 | compat_datafellows(remote_version); | |
446 | mismatch = 0; | |
447 | ||
e9a17296 | 448 | switch (remote_major) { |
3c0ef626 | 449 | case 1: |
450 | if (remote_minor == 99 && | |
451 | (options.protocol & SSH_PROTO_2) && | |
452 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { | |
453 | enable_compat20(); | |
454 | break; | |
455 | } | |
456 | if (!(options.protocol & SSH_PROTO_1)) { | |
457 | mismatch = 1; | |
458 | break; | |
459 | } | |
460 | if (remote_minor < 3) { | |
461 | fatal("Remote machine has too old SSH software version."); | |
462 | } else if (remote_minor == 3 || remote_minor == 4) { | |
463 | /* We speak 1.3, too. */ | |
464 | enable_compat13(); | |
465 | minor1 = 3; | |
466 | if (options.forward_agent) { | |
0fff78ff | 467 | logit("Agent forwarding disabled for protocol 1.3"); |
3c0ef626 | 468 | options.forward_agent = 0; |
469 | } | |
470 | } | |
471 | break; | |
472 | case 2: | |
473 | if (options.protocol & SSH_PROTO_2) { | |
474 | enable_compat20(); | |
475 | break; | |
476 | } | |
477 | /* FALLTHROUGH */ | |
478 | default: | |
479 | mismatch = 1; | |
480 | break; | |
481 | } | |
482 | if (mismatch) | |
483 | fatal("Protocol major versions differ: %d vs. %d", | |
484 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, | |
485 | remote_major); | |
486 | /* Send our own protocol version identification. */ | |
487 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | |
488 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, | |
489 | compat20 ? PROTOCOL_MINOR_2 : minor1, | |
490 | SSH_VERSION); | |
0fff78ff | 491 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
3c0ef626 | 492 | fatal("write: %.100s", strerror(errno)); |
493 | client_version_string = xstrdup(buf); | |
494 | chop(client_version_string); | |
495 | chop(server_version_string); | |
496 | debug("Local version string %.100s", client_version_string); | |
497 | } | |
498 | ||
499 | /* defaults to 'no' */ | |
500 | static int | |
501 | confirm(const char *prompt) | |
502 | { | |
e9a17296 | 503 | const char *msg, *again = "Please type 'yes' or 'no': "; |
504 | char *p; | |
505 | int ret = -1; | |
3c0ef626 | 506 | |
507 | if (options.batch_mode) | |
508 | return 0; | |
e9a17296 | 509 | for (msg = prompt;;msg = again) { |
510 | p = read_passphrase(msg, RP_ECHO); | |
511 | if (p == NULL || | |
512 | (p[0] == '\0') || (p[0] == '\n') || | |
513 | strncasecmp(p, "no", 2) == 0) | |
514 | ret = 0; | |
41b2f314 | 515 | if (p && strncasecmp(p, "yes", 3) == 0) |
e9a17296 | 516 | ret = 1; |
517 | if (p) | |
518 | xfree(p); | |
519 | if (ret != -1) | |
520 | return ret; | |
3c0ef626 | 521 | } |
522 | } | |
523 | ||
524 | /* | |
525 | * check whether the supplied host key is valid, return -1 if the key | |
526 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. | |
527 | */ | |
9108f8d9 | 528 | #define RDRW 0 |
529 | #define RDONLY 1 | |
530 | #define ROQUIET 2 | |
3c0ef626 | 531 | static int |
9108f8d9 | 532 | check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, |
533 | Key *host_key, int readonly, const char *user_hostfile, | |
534 | const char *system_hostfile) | |
3c0ef626 | 535 | { |
536 | Key *file_key; | |
cdd66111 | 537 | const char *type = key_type(host_key); |
9108f8d9 | 538 | char *ip = NULL, *host = NULL; |
3c0ef626 | 539 | char hostline[1000], *hostp, *fp; |
540 | HostStatus host_status; | |
541 | HostStatus ip_status; | |
996d5e62 | 542 | int r, local = 0, host_ip_differ = 0; |
3c0ef626 | 543 | int salen; |
544 | char ntop[NI_MAXHOST]; | |
e9a17296 | 545 | char msg[1024]; |
0fff78ff | 546 | int len, host_line, ip_line; |
3c0ef626 | 547 | const char *host_file = NULL, *ip_file = NULL; |
548 | ||
549 | /* | |
550 | * Force accepting of the host key for loopback/localhost. The | |
551 | * problem is that if the home directory is NFS-mounted to multiple | |
552 | * machines, localhost will refer to a different machine in each of | |
553 | * them, and the user will get bogus HOST_CHANGED warnings. This | |
554 | * essentially disables host authentication for localhost; however, | |
555 | * this is probably not a real problem. | |
556 | */ | |
557 | /** hostaddr == 0! */ | |
558 | switch (hostaddr->sa_family) { | |
559 | case AF_INET: | |
560 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> | |
665a873d | 561 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
3c0ef626 | 562 | salen = sizeof(struct sockaddr_in); |
563 | break; | |
564 | case AF_INET6: | |
565 | local = IN6_IS_ADDR_LOOPBACK( | |
566 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | |
567 | salen = sizeof(struct sockaddr_in6); | |
568 | break; | |
569 | default: | |
570 | local = 0; | |
571 | salen = sizeof(struct sockaddr_storage); | |
572 | break; | |
573 | } | |
574 | if (options.no_host_authentication_for_localhost == 1 && local && | |
575 | options.host_key_alias == NULL) { | |
576 | debug("Forcing accepting of host key for " | |
577 | "loopback/localhost."); | |
578 | return 0; | |
579 | } | |
580 | ||
581 | /* | |
582 | * We don't have the remote ip-address for connections | |
583 | * using a proxy command | |
584 | */ | |
585 | if (options.proxy_command == NULL) { | |
586 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), | |
587 | NULL, 0, NI_NUMERICHOST) != 0) | |
588 | fatal("check_host_key: getnameinfo failed"); | |
9108f8d9 | 589 | ip = put_host_port(ntop, port); |
3c0ef626 | 590 | } else { |
591 | ip = xstrdup("<no hostip for proxy command>"); | |
592 | } | |
593 | /* | |
594 | * Turn off check_host_ip if the connection is to localhost, via proxy | |
595 | * command or if we don't have a hostname to compare with | |
596 | */ | |
9108f8d9 | 597 | if (options.check_host_ip && (local || |
598 | strcmp(hostname, ip) == 0 || options.proxy_command != NULL)) | |
3c0ef626 | 599 | options.check_host_ip = 0; |
600 | ||
601 | /* | |
9108f8d9 | 602 | * Allow the user to record the key under a different name or |
603 | * differentiate a non-standard port. This is useful for ssh | |
604 | * tunneling over forwarded connections or if you run multiple | |
605 | * sshd's on different ports on the same machine. | |
3c0ef626 | 606 | */ |
607 | if (options.host_key_alias != NULL) { | |
9108f8d9 | 608 | host = xstrdup(options.host_key_alias); |
3c0ef626 | 609 | debug("using hostkeyalias: %s", host); |
9108f8d9 | 610 | } else { |
611 | host = put_host_port(hostname, port); | |
3c0ef626 | 612 | } |
613 | ||
614 | /* | |
615 | * Store the host key from the known host file in here so that we can | |
616 | * compare it with the key for the IP address. | |
617 | */ | |
618 | file_key = key_new(host_key->type); | |
619 | ||
620 | /* | |
2c06c99b | 621 | * Check if the host key is present in the user's list of known |
3c0ef626 | 622 | * hosts or in the systemwide list. |
623 | */ | |
624 | host_file = user_hostfile; | |
625 | host_status = check_host_in_hostfile(host_file, host, host_key, | |
e9a17296 | 626 | file_key, &host_line); |
3c0ef626 | 627 | if (host_status == HOST_NEW) { |
628 | host_file = system_hostfile; | |
629 | host_status = check_host_in_hostfile(host_file, host, host_key, | |
630 | file_key, &host_line); | |
631 | } | |
632 | /* | |
633 | * Also perform check for the ip address, skip the check if we are | |
634 | * localhost or the hostname was an ip address to begin with | |
635 | */ | |
636 | if (options.check_host_ip) { | |
637 | Key *ip_key = key_new(host_key->type); | |
638 | ||
639 | ip_file = user_hostfile; | |
640 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, | |
641 | ip_key, &ip_line); | |
642 | if (ip_status == HOST_NEW) { | |
643 | ip_file = system_hostfile; | |
644 | ip_status = check_host_in_hostfile(ip_file, ip, | |
645 | host_key, ip_key, &ip_line); | |
646 | } | |
647 | if (host_status == HOST_CHANGED && | |
648 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) | |
649 | host_ip_differ = 1; | |
650 | ||
651 | key_free(ip_key); | |
652 | } else | |
653 | ip_status = host_status; | |
654 | ||
655 | key_free(file_key); | |
656 | ||
657 | switch (host_status) { | |
658 | case HOST_OK: | |
659 | /* The host is known and the key matches. */ | |
660 | debug("Host '%.200s' is known and matches the %s host key.", | |
661 | host, type); | |
662 | debug("Found key in %s:%d", host_file, host_line); | |
663 | if (options.check_host_ip && ip_status == HOST_NEW) { | |
664 | if (readonly) | |
0fff78ff | 665 | logit("%s host key for IP address " |
3c0ef626 | 666 | "'%.128s' not in list of known hosts.", |
667 | type, ip); | |
668 | else if (!add_host_to_hostfile(user_hostfile, ip, | |
996d5e62 | 669 | host_key, options.hash_known_hosts)) |
0fff78ff | 670 | logit("Failed to add the %s host key for IP " |
3c0ef626 | 671 | "address '%.128s' to the list of known " |
672 | "hosts (%.30s).", type, ip, user_hostfile); | |
673 | else | |
0fff78ff | 674 | logit("Warning: Permanently added the %s host " |
3c0ef626 | 675 | "key for IP address '%.128s' to the list " |
676 | "of known hosts.", type, ip); | |
677 | } | |
678 | break; | |
679 | case HOST_NEW: | |
9108f8d9 | 680 | if (options.host_key_alias == NULL && port != 0 && |
681 | port != SSH_DEFAULT_PORT) { | |
682 | debug("checking without port identifier"); | |
683 | if (check_host_key(hostname, hostaddr, 0, host_key, 2, | |
684 | user_hostfile, system_hostfile) == 0) { | |
685 | debug("found matching key w/out port"); | |
686 | break; | |
687 | } | |
688 | } | |
3c0ef626 | 689 | if (readonly) |
690 | goto fail; | |
691 | /* The host is new. */ | |
692 | if (options.strict_host_key_checking == 1) { | |
693 | /* | |
694 | * User has requested strict host key checking. We | |
695 | * will not add the host key automatically. The only | |
696 | * alternative left is to abort. | |
697 | */ | |
698 | error("No %s host key is known for %.200s and you " | |
699 | "have requested strict checking.", type, host); | |
700 | goto fail; | |
701 | } else if (options.strict_host_key_checking == 2) { | |
0fff78ff | 702 | char msg1[1024], msg2[1024]; |
703 | ||
704 | if (show_other_keys(host, host_key)) | |
705 | snprintf(msg1, sizeof(msg1), | |
665a873d | 706 | "\nbut keys of different type are already" |
707 | " known for this host."); | |
0fff78ff | 708 | else |
709 | snprintf(msg1, sizeof(msg1), "."); | |
3c0ef626 | 710 | /* The default */ |
3c0ef626 | 711 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
0fff78ff | 712 | msg2[0] = '\0'; |
0fff78ff | 713 | if (options.verify_host_key_dns) { |
cdd66111 | 714 | if (matching_host_key_dns) |
0fff78ff | 715 | snprintf(msg2, sizeof(msg2), |
716 | "Matching host key fingerprint" | |
717 | " found in DNS.\n"); | |
718 | else | |
719 | snprintf(msg2, sizeof(msg2), | |
720 | "No matching host key fingerprint" | |
721 | " found in DNS.\n"); | |
722 | } | |
e9a17296 | 723 | snprintf(msg, sizeof(msg), |
3c0ef626 | 724 | "The authenticity of host '%.200s (%s)' can't be " |
41b2f314 | 725 | "established%s\n" |
0fff78ff | 726 | "%s key fingerprint is %s.\n%s" |
3c0ef626 | 727 | "Are you sure you want to continue connecting " |
41b2f314 | 728 | "(yes/no)? ", |
0fff78ff | 729 | host, ip, msg1, type, fp, msg2); |
3c0ef626 | 730 | xfree(fp); |
e9a17296 | 731 | if (!confirm(msg)) |
3c0ef626 | 732 | goto fail; |
3c0ef626 | 733 | } |
3c0ef626 | 734 | /* |
735 | * If not in strict mode, add the key automatically to the | |
736 | * local known_hosts file. | |
737 | */ | |
996d5e62 | 738 | if (options.check_host_ip && ip_status == HOST_NEW) { |
739 | snprintf(hostline, sizeof(hostline), "%s,%s", | |
740 | host, ip); | |
741 | hostp = hostline; | |
742 | if (options.hash_known_hosts) { | |
743 | /* Add hash of host and IP separately */ | |
744 | r = add_host_to_hostfile(user_hostfile, host, | |
745 | host_key, options.hash_known_hosts) && | |
746 | add_host_to_hostfile(user_hostfile, ip, | |
747 | host_key, options.hash_known_hosts); | |
748 | } else { | |
749 | /* Add unhashed "host,ip" */ | |
750 | r = add_host_to_hostfile(user_hostfile, | |
751 | hostline, host_key, | |
752 | options.hash_known_hosts); | |
753 | } | |
754 | } else { | |
755 | r = add_host_to_hostfile(user_hostfile, host, host_key, | |
756 | options.hash_known_hosts); | |
757 | hostp = host; | |
758 | } | |
759 | ||
760 | if (!r) | |
0fff78ff | 761 | logit("Failed to add the host to the list of known " |
3c0ef626 | 762 | "hosts (%.500s).", user_hostfile); |
763 | else | |
0fff78ff | 764 | logit("Warning: Permanently added '%.200s' (%s) to the " |
3c0ef626 | 765 | "list of known hosts.", hostp, type); |
766 | break; | |
767 | case HOST_CHANGED: | |
9108f8d9 | 768 | if (readonly == ROQUIET) |
769 | goto fail; | |
3c0ef626 | 770 | if (options.check_host_ip && host_ip_differ) { |
c9f39d2c | 771 | char *key_msg; |
3c0ef626 | 772 | if (ip_status == HOST_NEW) |
c9f39d2c | 773 | key_msg = "is unknown"; |
3c0ef626 | 774 | else if (ip_status == HOST_OK) |
c9f39d2c | 775 | key_msg = "is unchanged"; |
3c0ef626 | 776 | else |
c9f39d2c | 777 | key_msg = "has a different value"; |
3c0ef626 | 778 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
779 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); | |
780 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
781 | error("The %s host key for %s has changed,", type, host); | |
782 | error("and the key for the according IP address %s", ip); | |
c9f39d2c | 783 | error("%s. This could either mean that", key_msg); |
3c0ef626 | 784 | error("DNS SPOOFING is happening or the IP address for the host"); |
785 | error("and its host key have changed at the same time."); | |
786 | if (ip_status != HOST_NEW) | |
787 | error("Offending key for IP in %s:%d", ip_file, ip_line); | |
788 | } | |
789 | /* The host key has changed. */ | |
cdd66111 | 790 | warn_changed_key(host_key); |
3c0ef626 | 791 | error("Add correct host key in %.100s to get rid of this message.", |
792 | user_hostfile); | |
793 | error("Offending key in %s:%d", host_file, host_line); | |
3c0ef626 | 794 | |
795 | /* | |
796 | * If strict host key checking is in use, the user will have | |
797 | * to edit the key manually and we can only abort. | |
798 | */ | |
799 | if (options.strict_host_key_checking) { | |
800 | error("%s host key for %.200s has changed and you have " | |
801 | "requested strict checking.", type, host); | |
802 | goto fail; | |
803 | } | |
804 | ||
805 | /* | |
806 | * If strict host key checking has not been requested, allow | |
0fff78ff | 807 | * the connection but without MITM-able authentication or |
9108f8d9 | 808 | * forwarding. |
3c0ef626 | 809 | */ |
810 | if (options.password_authentication) { | |
811 | error("Password authentication is disabled to avoid " | |
812 | "man-in-the-middle attacks."); | |
813 | options.password_authentication = 0; | |
814 | } | |
0fff78ff | 815 | if (options.kbd_interactive_authentication) { |
816 | error("Keyboard-interactive authentication is disabled" | |
817 | " to avoid man-in-the-middle attacks."); | |
818 | options.kbd_interactive_authentication = 0; | |
819 | options.challenge_response_authentication = 0; | |
820 | } | |
821 | if (options.challenge_response_authentication) { | |
822 | error("Challenge/response authentication is disabled" | |
823 | " to avoid man-in-the-middle attacks."); | |
824 | options.challenge_response_authentication = 0; | |
825 | } | |
3c0ef626 | 826 | if (options.forward_agent) { |
827 | error("Agent forwarding is disabled to avoid " | |
828 | "man-in-the-middle attacks."); | |
829 | options.forward_agent = 0; | |
830 | } | |
831 | if (options.forward_x11) { | |
832 | error("X11 forwarding is disabled to avoid " | |
833 | "man-in-the-middle attacks."); | |
834 | options.forward_x11 = 0; | |
835 | } | |
836 | if (options.num_local_forwards > 0 || | |
837 | options.num_remote_forwards > 0) { | |
838 | error("Port forwarding is disabled to avoid " | |
839 | "man-in-the-middle attacks."); | |
840 | options.num_local_forwards = | |
e9a17296 | 841 | options.num_remote_forwards = 0; |
3c0ef626 | 842 | } |
9108f8d9 | 843 | if (options.tun_open != SSH_TUNMODE_NO) { |
844 | error("Tunnel forwarding is disabled to avoid " | |
845 | "man-in-the-middle attacks."); | |
846 | options.tun_open = SSH_TUNMODE_NO; | |
847 | } | |
3c0ef626 | 848 | /* |
849 | * XXX Should permit the user to change to use the new id. | |
850 | * This could be done by converting the host key to an | |
851 | * identifying sentence, tell that the host identifies itself | |
852 | * by that sentence, and ask the user if he/she whishes to | |
853 | * accept the authentication. | |
854 | */ | |
855 | break; | |
41b2f314 | 856 | case HOST_FOUND: |
857 | fatal("internal error"); | |
858 | break; | |
3c0ef626 | 859 | } |
860 | ||
861 | if (options.check_host_ip && host_status != HOST_CHANGED && | |
862 | ip_status == HOST_CHANGED) { | |
e9a17296 | 863 | snprintf(msg, sizeof(msg), |
864 | "Warning: the %s host key for '%.200s' " | |
865 | "differs from the key for the IP address '%.128s'" | |
866 | "\nOffending key for IP in %s:%d", | |
867 | type, host, ip, ip_file, ip_line); | |
868 | if (host_status == HOST_OK) { | |
869 | len = strlen(msg); | |
870 | snprintf(msg + len, sizeof(msg) - len, | |
871 | "\nMatching host key in %s:%d", | |
f5799ae1 | 872 | host_file, host_line); |
e9a17296 | 873 | } |
3c0ef626 | 874 | if (options.strict_host_key_checking == 1) { |
0fff78ff | 875 | logit("%s", msg); |
3c0ef626 | 876 | error("Exiting, you have requested strict checking."); |
877 | goto fail; | |
878 | } else if (options.strict_host_key_checking == 2) { | |
e9a17296 | 879 | strlcat(msg, "\nAre you sure you want " |
880 | "to continue connecting (yes/no)? ", sizeof(msg)); | |
881 | if (!confirm(msg)) | |
3c0ef626 | 882 | goto fail; |
e9a17296 | 883 | } else { |
0fff78ff | 884 | logit("%s", msg); |
3c0ef626 | 885 | } |
886 | } | |
887 | ||
888 | xfree(ip); | |
9108f8d9 | 889 | xfree(host); |
3c0ef626 | 890 | return 0; |
891 | ||
892 | fail: | |
893 | xfree(ip); | |
9108f8d9 | 894 | xfree(host); |
3c0ef626 | 895 | return -1; |
896 | } | |
897 | ||
0fff78ff | 898 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
3c0ef626 | 899 | int |
900 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) | |
901 | { | |
902 | struct stat st; | |
cdd66111 | 903 | int flags = 0; |
12408a1b | 904 | |
cdd66111 | 905 | if (options.verify_host_key_dns && |
906 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { | |
907 | ||
908 | if (flags & DNS_VERIFY_FOUND) { | |
909 | ||
910 | if (options.verify_host_key_dns == 1 && | |
911 | flags & DNS_VERIFY_MATCH && | |
912 | flags & DNS_VERIFY_SECURE) | |
913 | return 0; | |
914 | ||
915 | if (flags & DNS_VERIFY_MATCH) { | |
916 | matching_host_key_dns = 1; | |
917 | } else { | |
918 | warn_changed_key(host_key); | |
919 | error("Update the SSHFP RR in DNS with the new " | |
920 | "host key to get rid of this message."); | |
921 | } | |
0fff78ff | 922 | } |
923 | } | |
0fff78ff | 924 | |
3c0ef626 | 925 | /* return ok if the key can be found in an old keyfile */ |
926 | if (stat(options.system_hostfile2, &st) == 0 || | |
927 | stat(options.user_hostfile2, &st) == 0) { | |
9108f8d9 | 928 | if (check_host_key(host, hostaddr, options.port, host_key, |
929 | RDONLY, options.user_hostfile2, | |
930 | options.system_hostfile2) == 0) | |
3c0ef626 | 931 | return 0; |
932 | } | |
9108f8d9 | 933 | return check_host_key(host, hostaddr, options.port, host_key, |
934 | RDRW, options.user_hostfile, options.system_hostfile); | |
3c0ef626 | 935 | } |
936 | ||
937 | /* | |
938 | * Starts a dialog with the server, and authenticates the current user on the | |
939 | * server. This does not need any extra privileges. The basic connection | |
940 | * to the server must already have been established before this is called. | |
941 | * If login fails, this function prints an error and never returns. | |
942 | * This function does not require super-user privileges. | |
943 | */ | |
944 | void | |
f5799ae1 | 945 | ssh_login(Sensitive *sensitive, const char *orighost, |
3c0ef626 | 946 | struct sockaddr *hostaddr, struct passwd *pw) |
947 | { | |
948 | char *host, *cp; | |
949 | char *server_user, *local_user; | |
950 | ||
951 | local_user = xstrdup(pw->pw_name); | |
952 | server_user = options.user ? options.user : local_user; | |
953 | ||
954 | /* Convert the user-supplied hostname into all lowercase. */ | |
955 | host = xstrdup(orighost); | |
956 | for (cp = host; *cp; cp++) | |
957 | if (isupper(*cp)) | |
9108f8d9 | 958 | *cp = (char)tolower(*cp); |
3c0ef626 | 959 | |
960 | /* Exchange protocol version identification strings with the server. */ | |
961 | ssh_exchange_identification(); | |
962 | ||
963 | /* Put the connection into non-blocking mode. */ | |
964 | packet_set_nonblocking(); | |
965 | ||
966 | /* key exchange */ | |
967 | /* authenticate user */ | |
968 | if (compat20) { | |
969 | ssh_kex2(host, hostaddr); | |
f5799ae1 | 970 | ssh_userauth2(local_user, server_user, host, sensitive); |
3c0ef626 | 971 | } else { |
972 | ssh_kex(host, hostaddr); | |
f5799ae1 | 973 | ssh_userauth1(local_user, server_user, host, sensitive); |
3c0ef626 | 974 | } |
9108f8d9 | 975 | xfree(local_user); |
3c0ef626 | 976 | } |
977 | ||
978 | void | |
979 | ssh_put_password(char *password) | |
980 | { | |
981 | int size; | |
982 | char *padded; | |
983 | ||
984 | if (datafellows & SSH_BUG_PASSWORDPAD) { | |
985 | packet_put_cstring(password); | |
986 | return; | |
987 | } | |
988 | size = roundup(strlen(password) + 1, 32); | |
9108f8d9 | 989 | padded = xcalloc(1, size); |
3c0ef626 | 990 | strlcpy(padded, password, size); |
991 | packet_put_string(padded, size); | |
992 | memset(padded, 0, size); | |
993 | xfree(padded); | |
994 | } | |
41b2f314 | 995 | |
996 | static int | |
997 | show_key_from_file(const char *file, const char *host, int keytype) | |
998 | { | |
999 | Key *found; | |
1000 | char *fp; | |
1001 | int line, ret; | |
1002 | ||
1003 | found = key_new(keytype); | |
1004 | if ((ret = lookup_key_in_hostfile_by_type(file, host, | |
1005 | keytype, found, &line))) { | |
1006 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); | |
0fff78ff | 1007 | logit("WARNING: %s key found for host %s\n" |
41b2f314 | 1008 | "in %s:%d\n" |
1009 | "%s key fingerprint %s.", | |
1010 | key_type(found), host, file, line, | |
1011 | key_type(found), fp); | |
1012 | xfree(fp); | |
1013 | } | |
1014 | key_free(found); | |
1015 | return (ret); | |
1016 | } | |
1017 | ||
1018 | /* print all known host keys for a given host, but skip keys of given type */ | |
1019 | static int | |
1020 | show_other_keys(const char *host, Key *key) | |
1021 | { | |
1022 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; | |
1023 | int i, found = 0; | |
1024 | ||
1025 | for (i = 0; type[i] != -1; i++) { | |
1026 | if (type[i] == key->type) | |
1027 | continue; | |
1028 | if (type[i] != KEY_RSA1 && | |
1029 | show_key_from_file(options.user_hostfile2, host, type[i])) { | |
1030 | found = 1; | |
1031 | continue; | |
1032 | } | |
1033 | if (type[i] != KEY_RSA1 && | |
1034 | show_key_from_file(options.system_hostfile2, host, type[i])) { | |
1035 | found = 1; | |
1036 | continue; | |
1037 | } | |
1038 | if (show_key_from_file(options.user_hostfile, host, type[i])) { | |
1039 | found = 1; | |
1040 | continue; | |
1041 | } | |
1042 | if (show_key_from_file(options.system_hostfile, host, type[i])) { | |
1043 | found = 1; | |
1044 | continue; | |
1045 | } | |
1046 | debug2("no key of type %d for host %s", type[i], host); | |
1047 | } | |
1048 | return (found); | |
1049 | } | |
cdd66111 | 1050 | |
1051 | static void | |
1052 | warn_changed_key(Key *host_key) | |
1053 | { | |
1054 | char *fp; | |
1055 | const char *type = key_type(host_key); | |
1056 | ||
1057 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); | |
1058 | ||
1059 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1060 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); | |
1061 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1062 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); | |
1063 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); | |
1064 | error("It is also possible that the %s host key has just been changed.", type); | |
1065 | error("The fingerprint for the %s key sent by the remote host is\n%s.", | |
1066 | type, fp); | |
1067 | error("Please contact your system administrator."); | |
1068 | ||
1069 | xfree(fp); | |
1070 | } | |
2c06c99b | 1071 | |
1072 | /* | |
1073 | * Execute a local command | |
1074 | */ | |
1075 | int | |
1076 | ssh_local_cmd(const char *args) | |
1077 | { | |
1078 | char *shell; | |
1079 | pid_t pid; | |
1080 | int status; | |
1081 | ||
1082 | if (!options.permit_local_command || | |
1083 | args == NULL || !*args) | |
1084 | return (1); | |
1085 | ||
1086 | if ((shell = getenv("SHELL")) == NULL) | |
1087 | shell = _PATH_BSHELL; | |
1088 | ||
1089 | pid = fork(); | |
1090 | if (pid == 0) { | |
1091 | debug3("Executing %s -c \"%s\"", shell, args); | |
1092 | execl(shell, shell, "-c", args, (char *)NULL); | |
1093 | error("Couldn't execute %s -c \"%s\": %s", | |
1094 | shell, args, strerror(errno)); | |
1095 | _exit(1); | |
1096 | } else if (pid == -1) | |
1097 | fatal("fork failed: %.100s", strerror(errno)); | |
1098 | while (waitpid(pid, &status, 0) == -1) | |
1099 | if (errno != EINTR) | |
1100 | fatal("Couldn't wait for child: %s", strerror(errno)); | |
1101 | ||
1102 | if (!WIFEXITED(status)) | |
1103 | return (1); | |
1104 | ||
1105 | return (WEXITSTATUS(status)); | |
1106 | } |