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82aeee5d | 1 | /* $OpenBSD: sshconnect.c,v 1.183 2006/06/06 10:20:20 markus Exp $ */ |
8efc0c15 | 2 | /* |
5260325f | 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
5 | * All rights reserved | |
5260325f | 6 | * Code to connect to a remote host, and to perform the client side of the |
7 | * login (authentication) dialog. | |
bcbf86ec | 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". | |
5260325f | 14 | */ |
8efc0c15 | 15 | |
16 | #include "includes.h" | |
aa2eae64 | 17 | |
18 | #include <sys/types.h> | |
19 | #include <sys/wait.h> | |
4095f623 | 20 | #include <sys/stat.h> |
a75f5360 | 21 | |
b6438382 | 22 | #include <ctype.h> |
b5b88c19 | 23 | #ifdef HAVE_PATHS_H |
a75f5360 | 24 | #include <paths.h> |
b5b88c19 | 25 | #endif |
8efc0c15 | 26 | |
42f11eb2 | 27 | #include "ssh.h" |
8efc0c15 | 28 | #include "xmalloc.h" |
29 | #include "rsa.h" | |
8ce64345 | 30 | #include "buffer.h" |
8efc0c15 | 31 | #include "packet.h" |
8efc0c15 | 32 | #include "uidswap.h" |
33 | #include "compat.h" | |
4fe2af09 | 34 | #include "key.h" |
a306f2dd | 35 | #include "sshconnect.h" |
4fe2af09 | 36 | #include "hostfile.h" |
42f11eb2 | 37 | #include "log.h" |
38 | #include "readconf.h" | |
39 | #include "atomicio.h" | |
40 | #include "misc.h" | |
21289cd0 | 41 | #include "dns.h" |
21289cd0 | 42 | |
a306f2dd | 43 | char *client_version_string = NULL; |
44 | char *server_version_string = NULL; | |
8ce64345 | 45 | |
ed82a2a9 | 46 | static int matching_host_key_dns = 0; |
1432b5c4 | 47 | |
3fb156df | 48 | /* import */ |
57112b5a | 49 | extern Options options; |
48e671d5 | 50 | extern char *__progname; |
3fb156df | 51 | extern uid_t original_real_uid; |
52 | extern uid_t original_effective_uid; | |
6939bbd4 | 53 | extern pid_t proxy_command_pid; |
57112b5a | 54 | |
a704dd54 | 55 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ |
56 | #define INET6_ADDRSTRLEN 46 | |
57 | #endif | |
58 | ||
8a48a7ef | 59 | static int show_other_keys(const char *, Key *); |
1a1bc5d5 | 60 | static void warn_changed_key(Key *); |
8a48a7ef | 61 | |
5260325f | 62 | /* |
63 | * Connect to the given ssh server using a proxy command. | |
64 | */ | |
396c147e | 65 | static int |
3fb156df | 66 | ssh_proxy_connect(const char *host, u_short port, const char *proxy_command) |
8efc0c15 | 67 | { |
a980cbd7 | 68 | char *command_string, *tmp; |
5260325f | 69 | int pin[2], pout[2]; |
9da5c3c9 | 70 | pid_t pid; |
48e671d5 | 71 | char strport[NI_MAXSERV]; |
5260325f | 72 | |
73 | /* Convert the port number into a string. */ | |
48e671d5 | 74 | snprintf(strport, sizeof strport, "%hu", port); |
5260325f | 75 | |
6939bbd4 | 76 | /* |
77 | * Build the final command string in the buffer by making the | |
78 | * appropriate substitutions to the given proxy command. | |
79 | * | |
aff51935 | 80 | * Use "exec" to avoid "sh -c" processes on some platforms |
6939bbd4 | 81 | * (e.g. Solaris) |
82 | */ | |
52e3daed | 83 | xasprintf(&tmp, "exec %s", proxy_command); |
a980cbd7 | 84 | command_string = percent_expand(tmp, "h", host, |
85 | "p", strport, (char *)NULL); | |
86 | xfree(tmp); | |
5260325f | 87 | |
88 | /* Create pipes for communicating with the proxy. */ | |
89 | if (pipe(pin) < 0 || pipe(pout) < 0) | |
90 | fatal("Could not create pipes to communicate with the proxy: %.100s", | |
184eed6a | 91 | strerror(errno)); |
5260325f | 92 | |
93 | debug("Executing proxy command: %.500s", command_string); | |
94 | ||
95 | /* Fork and execute the proxy command. */ | |
96 | if ((pid = fork()) == 0) { | |
97 | char *argv[10]; | |
98 | ||
99 | /* Child. Permanently give up superuser privileges. */ | |
82aeee5d | 100 | permanently_set_uid(getpwuid(original_real_uid)); |
5260325f | 101 | |
102 | /* Redirect stdin and stdout. */ | |
103 | close(pin[1]); | |
104 | if (pin[0] != 0) { | |
105 | if (dup2(pin[0], 0) < 0) | |
106 | perror("dup2 stdin"); | |
107 | close(pin[0]); | |
108 | } | |
109 | close(pout[0]); | |
110 | if (dup2(pout[1], 1) < 0) | |
111 | perror("dup2 stdout"); | |
112 | /* Cannot be 1 because pin allocated two descriptors. */ | |
113 | close(pout[1]); | |
114 | ||
115 | /* Stderr is left as it is so that error messages get | |
116 | printed on the user's terminal. */ | |
30228d7c | 117 | argv[0] = _PATH_BSHELL; |
5260325f | 118 | argv[1] = "-c"; |
119 | argv[2] = command_string; | |
120 | argv[3] = NULL; | |
121 | ||
122 | /* Execute the proxy command. Note that we gave up any | |
123 | extra privileges above. */ | |
328654d8 | 124 | execv(argv[0], argv); |
125 | perror(argv[0]); | |
5260325f | 126 | exit(1); |
8efc0c15 | 127 | } |
5260325f | 128 | /* Parent. */ |
129 | if (pid < 0) | |
130 | fatal("fork failed: %.100s", strerror(errno)); | |
6939bbd4 | 131 | else |
132 | proxy_command_pid = pid; /* save pid to clean up later */ | |
5260325f | 133 | |
134 | /* Close child side of the descriptors. */ | |
135 | close(pin[0]); | |
136 | close(pout[1]); | |
137 | ||
138 | /* Free the command name. */ | |
a980cbd7 | 139 | xfree(command_string); |
5260325f | 140 | |
141 | /* Set the connection file descriptors. */ | |
142 | packet_set_connection(pout[0], pin[1]); | |
8efc0c15 | 143 | |
ce773142 | 144 | /* Indicate OK return */ |
145 | return 0; | |
5260325f | 146 | } |
8efc0c15 | 147 | |
5260325f | 148 | /* |
149 | * Creates a (possibly privileged) socket for use as the ssh connection. | |
150 | */ | |
396c147e | 151 | static int |
3e131a6d | 152 | ssh_create_socket(int privileged, struct addrinfo *ai) |
8efc0c15 | 153 | { |
3435f5a6 | 154 | int sock, gaierr; |
155 | struct addrinfo hints, *res; | |
5260325f | 156 | |
aa3378df | 157 | /* |
158 | * If we are running as root and want to connect to a privileged | |
159 | * port, bind our own socket to a privileged port. | |
160 | */ | |
5260325f | 161 | if (privileged) { |
162 | int p = IPPORT_RESERVED - 1; | |
3fb156df | 163 | PRIV_START; |
3e131a6d | 164 | sock = rresvport_af(&p, ai->ai_family); |
3fb156df | 165 | PRIV_END; |
5260325f | 166 | if (sock < 0) |
3e131a6d | 167 | error("rresvport: af=%d %.100s", ai->ai_family, |
168 | strerror(errno)); | |
c8d54615 | 169 | else |
170 | debug("Allocated local port %d.", p); | |
3435f5a6 | 171 | return sock; |
172 | } | |
3e131a6d | 173 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3435f5a6 | 174 | if (sock < 0) |
175 | error("socket: %.100s", strerror(errno)); | |
3435f5a6 | 176 | |
177 | /* Bind the socket to an alternative local IP address */ | |
178 | if (options.bind_address == NULL) | |
179 | return sock; | |
180 | ||
181 | memset(&hints, 0, sizeof(hints)); | |
3e131a6d | 182 | hints.ai_family = ai->ai_family; |
183 | hints.ai_socktype = ai->ai_socktype; | |
184 | hints.ai_protocol = ai->ai_protocol; | |
3435f5a6 | 185 | hints.ai_flags = AI_PASSIVE; |
186 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); | |
187 | if (gaierr) { | |
188 | error("getaddrinfo: %s: %s", options.bind_address, | |
189 | gai_strerror(gaierr)); | |
190 | close(sock); | |
191 | return -1; | |
192 | } | |
193 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { | |
194 | error("bind: %s: %s", options.bind_address, strerror(errno)); | |
195 | close(sock); | |
196 | freeaddrinfo(res); | |
197 | return -1; | |
5260325f | 198 | } |
3435f5a6 | 199 | freeaddrinfo(res); |
5260325f | 200 | return sock; |
8efc0c15 | 201 | } |
202 | ||
09ab3296 | 203 | static int |
204 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, | |
205 | socklen_t addrlen, int timeout) | |
206 | { | |
207 | fd_set *fdset; | |
208 | struct timeval tv; | |
209 | socklen_t optlen; | |
52e3daed | 210 | int optval, rc, result = -1; |
09ab3296 | 211 | |
212 | if (timeout <= 0) | |
213 | return (connect(sockfd, serv_addr, addrlen)); | |
214 | ||
2daf1db1 | 215 | set_nonblock(sockfd); |
09ab3296 | 216 | rc = connect(sockfd, serv_addr, addrlen); |
2daf1db1 | 217 | if (rc == 0) { |
218 | unset_nonblock(sockfd); | |
09ab3296 | 219 | return (0); |
2daf1db1 | 220 | } |
09ab3296 | 221 | if (errno != EINPROGRESS) |
222 | return (-1); | |
223 | ||
52e3daed | 224 | fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS), |
225 | sizeof(fd_mask)); | |
09ab3296 | 226 | FD_SET(sockfd, fdset); |
227 | tv.tv_sec = timeout; | |
228 | tv.tv_usec = 0; | |
229 | ||
f8cc7664 | 230 | for (;;) { |
09ab3296 | 231 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
232 | if (rc != -1 || errno != EINTR) | |
233 | break; | |
234 | } | |
235 | ||
f8cc7664 | 236 | switch (rc) { |
09ab3296 | 237 | case 0: |
238 | /* Timed out */ | |
239 | errno = ETIMEDOUT; | |
da54f5be | 240 | break; |
09ab3296 | 241 | case -1: |
242 | /* Select error */ | |
aff51935 | 243 | debug("select: %s", strerror(errno)); |
da54f5be | 244 | break; |
09ab3296 | 245 | case 1: |
246 | /* Completed or failed */ | |
247 | optval = 0; | |
248 | optlen = sizeof(optval); | |
aff51935 | 249 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
ce26c02a | 250 | &optlen) == -1) { |
aff51935 | 251 | debug("getsockopt: %s", strerror(errno)); |
da54f5be | 252 | break; |
ce26c02a | 253 | } |
09ab3296 | 254 | if (optval != 0) { |
255 | errno = optval; | |
da54f5be | 256 | break; |
09ab3296 | 257 | } |
da54f5be | 258 | result = 0; |
2daf1db1 | 259 | unset_nonblock(sockfd); |
09ab3296 | 260 | break; |
261 | default: | |
262 | /* Should not occur */ | |
263 | fatal("Bogus return (%d) from select()", rc); | |
264 | } | |
265 | ||
da54f5be | 266 | xfree(fdset); |
267 | return (result); | |
09ab3296 | 268 | } |
269 | ||
5260325f | 270 | /* |
48e671d5 | 271 | * Opens a TCP/IP connection to the remote server on the given host. |
272 | * The address of the remote host will be returned in hostaddr. | |
3fb156df | 273 | * If port is 0, the default port will be used. If needpriv is true, |
5260325f | 274 | * a privileged port will be allocated to make the connection. |
3fb156df | 275 | * This requires super-user privileges if needpriv is true. |
5260325f | 276 | * Connection_attempts specifies the maximum number of tries (one per |
277 | * second). If proxy_command is non-NULL, it specifies the command (with %h | |
278 | * and %p substituted for host and port, respectively) to use to contact | |
279 | * the daemon. | |
280 | */ | |
281 | int | |
48e671d5 | 282 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
dab89049 | 283 | u_short port, int family, int connection_attempts, |
3fb156df | 284 | int needpriv, const char *proxy_command) |
8efc0c15 | 285 | { |
b5c334cc | 286 | int gaierr; |
287 | int on = 1; | |
48e671d5 | 288 | int sock = -1, attempt; |
48e671d5 | 289 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
b5c334cc | 290 | struct addrinfo hints, *ai, *aitop; |
5260325f | 291 | |
a77673cc | 292 | debug2("ssh_connect: needpriv %d", needpriv); |
5260325f | 293 | |
5260325f | 294 | /* If a proxy command is given, connect using it. */ |
295 | if (proxy_command != NULL) | |
3fb156df | 296 | return ssh_proxy_connect(host, port, proxy_command); |
5260325f | 297 | |
298 | /* No proxy command. */ | |
299 | ||
48e671d5 | 300 | memset(&hints, 0, sizeof(hints)); |
dab89049 | 301 | hints.ai_family = family; |
48e671d5 | 302 | hints.ai_socktype = SOCK_STREAM; |
d6133f43 | 303 | snprintf(strport, sizeof strport, "%u", port); |
48e671d5 | 304 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
305 | fatal("%s: %.100s: %s", __progname, host, | |
306 | gai_strerror(gaierr)); | |
5260325f | 307 | |
4439dde1 | 308 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
5260325f | 309 | if (attempt > 0) |
310 | debug("Trying again..."); | |
311 | ||
4439dde1 | 312 | /* |
313 | * Loop through addresses for this host, and try each one in | |
314 | * sequence until the connection succeeds. | |
315 | */ | |
48e671d5 | 316 | for (ai = aitop; ai; ai = ai->ai_next) { |
317 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
318 | continue; | |
319 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
320 | ntop, sizeof(ntop), strport, sizeof(strport), | |
321 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
322 | error("ssh_connect: getnameinfo failed"); | |
323 | continue; | |
324 | } | |
325 | debug("Connecting to %.200s [%.100s] port %s.", | |
326 | host, ntop, strport); | |
327 | ||
328 | /* Create a socket for connecting. */ | |
3e131a6d | 329 | sock = ssh_create_socket(needpriv, ai); |
48e671d5 | 330 | if (sock < 0) |
ce773142 | 331 | /* Any error is already output */ |
48e671d5 | 332 | continue; |
333 | ||
09ab3296 | 334 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
335 | options.connection_timeout) >= 0) { | |
48e671d5 | 336 | /* Successful connection. */ |
cd332296 | 337 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
5260325f | 338 | break; |
48e671d5 | 339 | } else { |
c750d869 | 340 | debug("connect to address %s port %s: %s", |
341 | ntop, strport, strerror(errno)); | |
5260325f | 342 | close(sock); |
4439dde1 | 343 | sock = -1; |
5260325f | 344 | } |
8efc0c15 | 345 | } |
4439dde1 | 346 | if (sock != -1) |
48e671d5 | 347 | break; /* Successful connection. */ |
8efc0c15 | 348 | |
5260325f | 349 | /* Sleep a moment before retrying. */ |
350 | sleep(1); | |
351 | } | |
48e671d5 | 352 | |
353 | freeaddrinfo(aitop); | |
354 | ||
5260325f | 355 | /* Return failure if we didn't get a successful connection. */ |
4439dde1 | 356 | if (sock == -1) { |
cf039bd1 | 357 | error("ssh: connect to host %s port %s: %s", |
9bd68577 | 358 | host, strport, strerror(errno)); |
cf039bd1 | 359 | return (-1); |
9bd68577 | 360 | } |
8efc0c15 | 361 | |
5260325f | 362 | debug("Connection established."); |
8efc0c15 | 363 | |
fd573618 | 364 | /* Set SO_KEEPALIVE if requested. */ |
365 | if (options.tcp_keep_alive && | |
b5c334cc | 366 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
367 | sizeof(on)) < 0) | |
368 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
8efc0c15 | 369 | |
5260325f | 370 | /* Set the connection. */ |
371 | packet_set_connection(sock, sock); | |
8efc0c15 | 372 | |
ce773142 | 373 | return 0; |
8efc0c15 | 374 | } |
375 | ||
5260325f | 376 | /* |
377 | * Waits for the server identification string, and sends our own | |
378 | * identification string. | |
379 | */ | |
396c147e | 380 | static void |
5ca51e19 | 381 | ssh_exchange_identification(void) |
8efc0c15 | 382 | { |
5260325f | 383 | char buf[256], remote_version[256]; /* must be same size! */ |
2ceb8101 | 384 | int remote_major, remote_minor, mismatch; |
5260325f | 385 | int connection_in = packet_get_connection_in(); |
386 | int connection_out = packet_get_connection_out(); | |
2b87da3b | 387 | int minor1 = PROTOCOL_MINOR_1; |
2ceb8101 | 388 | u_int i; |
5260325f | 389 | |
05624c18 | 390 | /* Read other side's version identification. */ |
38c295d6 | 391 | for (;;) { |
392 | for (i = 0; i < sizeof(buf) - 1; i++) { | |
05624c18 | 393 | size_t len = atomicio(read, connection_in, &buf[i], 1); |
394 | ||
56964485 | 395 | if (len != 1 && errno == EPIPE) |
38c295d6 | 396 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
05624c18 | 397 | else if (len != 1) |
398 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); | |
38c295d6 | 399 | if (buf[i] == '\r') { |
400 | buf[i] = '\n'; | |
401 | buf[i + 1] = 0; | |
402 | continue; /**XXX wait for \n */ | |
403 | } | |
404 | if (buf[i] == '\n') { | |
405 | buf[i + 1] = 0; | |
406 | break; | |
407 | } | |
5260325f | 408 | } |
38c295d6 | 409 | buf[sizeof(buf) - 1] = 0; |
410 | if (strncmp(buf, "SSH-", 4) == 0) | |
5260325f | 411 | break; |
38c295d6 | 412 | debug("ssh_exchange_identification: %s", buf); |
8efc0c15 | 413 | } |
8ce64345 | 414 | server_version_string = xstrdup(buf); |
5260325f | 415 | |
aa3378df | 416 | /* |
417 | * Check that the versions match. In future this might accept | |
418 | * several versions and set appropriate flags to handle them. | |
419 | */ | |
8ce64345 | 420 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
421 | &remote_major, &remote_minor, remote_version) != 3) | |
5260325f | 422 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
423 | debug("Remote protocol version %d.%d, remote software version %.100s", | |
184eed6a | 424 | remote_major, remote_minor, remote_version); |
5260325f | 425 | |
8ce64345 | 426 | compat_datafellows(remote_version); |
a8be9f80 | 427 | mismatch = 0; |
428 | ||
6aacefa7 | 429 | switch (remote_major) { |
a8be9f80 | 430 | case 1: |
431 | if (remote_minor == 99 && | |
432 | (options.protocol & SSH_PROTO_2) && | |
433 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { | |
434 | enable_compat20(); | |
435 | break; | |
5260325f | 436 | } |
a8be9f80 | 437 | if (!(options.protocol & SSH_PROTO_1)) { |
438 | mismatch = 1; | |
439 | break; | |
440 | } | |
441 | if (remote_minor < 3) { | |
442 | fatal("Remote machine has too old SSH software version."); | |
fa08c86b | 443 | } else if (remote_minor == 3 || remote_minor == 4) { |
a8be9f80 | 444 | /* We speak 1.3, too. */ |
445 | enable_compat13(); | |
fa08c86b | 446 | minor1 = 3; |
a8be9f80 | 447 | if (options.forward_agent) { |
bbe88b6d | 448 | logit("Agent forwarding disabled for protocol 1.3"); |
a8be9f80 | 449 | options.forward_agent = 0; |
450 | } | |
451 | } | |
452 | break; | |
453 | case 2: | |
454 | if (options.protocol & SSH_PROTO_2) { | |
455 | enable_compat20(); | |
456 | break; | |
457 | } | |
458 | /* FALLTHROUGH */ | |
6ae2364d | 459 | default: |
a8be9f80 | 460 | mismatch = 1; |
461 | break; | |
8efc0c15 | 462 | } |
a8be9f80 | 463 | if (mismatch) |
5260325f | 464 | fatal("Protocol major versions differ: %d vs. %d", |
a8be9f80 | 465 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
466 | remote_major); | |
5260325f | 467 | /* Send our own protocol version identification. */ |
468 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | |
a8be9f80 | 469 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
fa08c86b | 470 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
8ce64345 | 471 | SSH_VERSION); |
dc54438a | 472 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
5260325f | 473 | fatal("write: %.100s", strerror(errno)); |
8ce64345 | 474 | client_version_string = xstrdup(buf); |
475 | chop(client_version_string); | |
476 | chop(server_version_string); | |
477 | debug("Local version string %.100s", client_version_string); | |
8efc0c15 | 478 | } |
479 | ||
f21032a6 | 480 | /* defaults to 'no' */ |
396c147e | 481 | static int |
a2c92c4a | 482 | confirm(const char *prompt) |
8efc0c15 | 483 | { |
616a6b93 | 484 | const char *msg, *again = "Please type 'yes' or 'no': "; |
485 | char *p; | |
486 | int ret = -1; | |
5260325f | 487 | |
f21032a6 | 488 | if (options.batch_mode) |
489 | return 0; | |
616a6b93 | 490 | for (msg = prompt;;msg = again) { |
491 | p = read_passphrase(msg, RP_ECHO); | |
492 | if (p == NULL || | |
493 | (p[0] == '\0') || (p[0] == '\n') || | |
494 | strncasecmp(p, "no", 2) == 0) | |
495 | ret = 0; | |
f11fe301 | 496 | if (p && strncasecmp(p, "yes", 3) == 0) |
616a6b93 | 497 | ret = 1; |
498 | if (p) | |
499 | xfree(p); | |
500 | if (ret != -1) | |
501 | return ret; | |
8efc0c15 | 502 | } |
8efc0c15 | 503 | } |
504 | ||
5260325f | 505 | /* |
f49bc4f7 | 506 | * check whether the supplied host key is valid, return -1 if the key |
507 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. | |
5260325f | 508 | */ |
396c147e | 509 | static int |
a306f2dd | 510 | check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, |
f49bc4f7 | 511 | int readonly, const char *user_hostfile, const char *system_hostfile) |
8efc0c15 | 512 | { |
4fe2af09 | 513 | Key *file_key; |
b6c7b7b7 | 514 | const char *type = key_type(host_key); |
95f1eccc | 515 | char *ip = NULL; |
22138a36 | 516 | char hostline[1000], *hostp, *fp; |
5260325f | 517 | HostStatus host_status; |
518 | HostStatus ip_status; | |
e79276c2 | 519 | int r, local = 0, host_ip_differ = 0; |
20af321f | 520 | int salen; |
48e671d5 | 521 | char ntop[NI_MAXHOST]; |
616a6b93 | 522 | char msg[1024]; |
1432b5c4 | 523 | int len, host_line, ip_line; |
1e3b8b07 | 524 | const char *host_file = NULL, *ip_file = NULL; |
48e671d5 | 525 | |
526 | /* | |
527 | * Force accepting of the host key for loopback/localhost. The | |
528 | * problem is that if the home directory is NFS-mounted to multiple | |
529 | * machines, localhost will refer to a different machine in each of | |
530 | * them, and the user will get bogus HOST_CHANGED warnings. This | |
531 | * essentially disables host authentication for localhost; however, | |
532 | * this is probably not a real problem. | |
533 | */ | |
a306f2dd | 534 | /** hostaddr == 0! */ |
48e671d5 | 535 | switch (hostaddr->sa_family) { |
536 | case AF_INET: | |
f49bc4f7 | 537 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
4e2e5cfd | 538 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
20af321f | 539 | salen = sizeof(struct sockaddr_in); |
48e671d5 | 540 | break; |
541 | case AF_INET6: | |
f49bc4f7 | 542 | local = IN6_IS_ADDR_LOOPBACK( |
543 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | |
20af321f | 544 | salen = sizeof(struct sockaddr_in6); |
48e671d5 | 545 | break; |
546 | default: | |
547 | local = 0; | |
20af321f | 548 | salen = sizeof(struct sockaddr_storage); |
48e671d5 | 549 | break; |
550 | } | |
8bbc048a | 551 | if (options.no_host_authentication_for_localhost == 1 && local && |
552 | options.host_key_alias == NULL) { | |
7c49df64 | 553 | debug("Forcing accepting of host key for " |
554 | "loopback/localhost."); | |
f49bc4f7 | 555 | return 0; |
48e671d5 | 556 | } |
5260325f | 557 | |
57112b5a | 558 | /* |
7c49df64 | 559 | * We don't have the remote ip-address for connections |
560 | * using a proxy command | |
561 | */ | |
562 | if (options.proxy_command == NULL) { | |
563 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), | |
564 | NULL, 0, NI_NUMERICHOST) != 0) | |
565 | fatal("check_host_key: getnameinfo failed"); | |
566 | ip = xstrdup(ntop); | |
567 | } else { | |
568 | ip = xstrdup("<no hostip for proxy command>"); | |
569 | } | |
570 | /* | |
571 | * Turn off check_host_ip if the connection is to localhost, via proxy | |
572 | * command or if we don't have a hostname to compare with | |
57112b5a | 573 | */ |
7c49df64 | 574 | if (options.check_host_ip && |
575 | (local || strcmp(host, ip) == 0 || options.proxy_command != NULL)) | |
57112b5a | 576 | options.check_host_ip = 0; |
577 | ||
8abcdba4 | 578 | /* |
7c49df64 | 579 | * Allow the user to record the key under a different name. This is |
8abcdba4 | 580 | * useful for ssh tunneling over forwarded connections or if you run |
7c49df64 | 581 | * multiple sshd's on different ports on the same machine. |
8abcdba4 | 582 | */ |
583 | if (options.host_key_alias != NULL) { | |
584 | host = options.host_key_alias; | |
585 | debug("using hostkeyalias: %s", host); | |
586 | } | |
587 | ||
95f1eccc | 588 | /* |
589 | * Store the host key from the known host file in here so that we can | |
590 | * compare it with the key for the IP address. | |
591 | */ | |
4fe2af09 | 592 | file_key = key_new(host_key->type); |
5260325f | 593 | |
aa3378df | 594 | /* |
7b9b0103 | 595 | * Check if the host key is present in the user's list of known |
aa3378df | 596 | * hosts or in the systemwide list. |
597 | */ | |
1e3b8b07 | 598 | host_file = user_hostfile; |
f49bc4f7 | 599 | host_status = check_host_in_hostfile(host_file, host, host_key, |
184eed6a | 600 | file_key, &host_line); |
1e3b8b07 | 601 | if (host_status == HOST_NEW) { |
602 | host_file = system_hostfile; | |
f49bc4f7 | 603 | host_status = check_host_in_hostfile(host_file, host, host_key, |
604 | file_key, &host_line); | |
1e3b8b07 | 605 | } |
aa3378df | 606 | /* |
607 | * Also perform check for the ip address, skip the check if we are | |
608 | * localhost or the hostname was an ip address to begin with | |
609 | */ | |
7c49df64 | 610 | if (options.check_host_ip) { |
4fe2af09 | 611 | Key *ip_key = key_new(host_key->type); |
5260325f | 612 | |
1e3b8b07 | 613 | ip_file = user_hostfile; |
f49bc4f7 | 614 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
615 | ip_key, &ip_line); | |
1e3b8b07 | 616 | if (ip_status == HOST_NEW) { |
617 | ip_file = system_hostfile; | |
f49bc4f7 | 618 | ip_status = check_host_in_hostfile(ip_file, ip, |
619 | host_key, ip_key, &ip_line); | |
1e3b8b07 | 620 | } |
5260325f | 621 | if (host_status == HOST_CHANGED && |
4fe2af09 | 622 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
5260325f | 623 | host_ip_differ = 1; |
624 | ||
4fe2af09 | 625 | key_free(ip_key); |
5260325f | 626 | } else |
627 | ip_status = host_status; | |
628 | ||
4fe2af09 | 629 | key_free(file_key); |
5260325f | 630 | |
631 | switch (host_status) { | |
632 | case HOST_OK: | |
633 | /* The host is known and the key matches. */ | |
1d1ffb87 | 634 | debug("Host '%.200s' is known and matches the %s host key.", |
635 | host, type); | |
1e3b8b07 | 636 | debug("Found key in %s:%d", host_file, host_line); |
7c49df64 | 637 | if (options.check_host_ip && ip_status == HOST_NEW) { |
f49bc4f7 | 638 | if (readonly) |
bbe88b6d | 639 | logit("%s host key for IP address " |
f49bc4f7 | 640 | "'%.128s' not in list of known hosts.", |
7c49df64 | 641 | type, ip); |
f49bc4f7 | 642 | else if (!add_host_to_hostfile(user_hostfile, ip, |
5c63c2ab | 643 | host_key, options.hash_known_hosts)) |
bbe88b6d | 644 | logit("Failed to add the %s host key for IP " |
f49bc4f7 | 645 | "address '%.128s' to the list of known " |
646 | "hosts (%.30s).", type, ip, user_hostfile); | |
647 | else | |
bbe88b6d | 648 | logit("Warning: Permanently added the %s host " |
f49bc4f7 | 649 | "key for IP address '%.128s' to the list " |
650 | "of known hosts.", type, ip); | |
5260325f | 651 | } |
652 | break; | |
653 | case HOST_NEW: | |
f49bc4f7 | 654 | if (readonly) |
655 | goto fail; | |
5260325f | 656 | /* The host is new. */ |
657 | if (options.strict_host_key_checking == 1) { | |
f49bc4f7 | 658 | /* |
659 | * User has requested strict host key checking. We | |
660 | * will not add the host key automatically. The only | |
661 | * alternative left is to abort. | |
662 | */ | |
663 | error("No %s host key is known for %.200s and you " | |
664 | "have requested strict checking.", type, host); | |
665 | goto fail; | |
5260325f | 666 | } else if (options.strict_host_key_checking == 2) { |
1432b5c4 | 667 | char msg1[1024], msg2[1024]; |
668 | ||
669 | if (show_other_keys(host, host_key)) | |
670 | snprintf(msg1, sizeof(msg1), | |
4e2e5cfd | 671 | "\nbut keys of different type are already" |
672 | " known for this host."); | |
1432b5c4 | 673 | else |
674 | snprintf(msg1, sizeof(msg1), "."); | |
5260325f | 675 | /* The default */ |
22138a36 | 676 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
1432b5c4 | 677 | msg2[0] = '\0'; |
1432b5c4 | 678 | if (options.verify_host_key_dns) { |
0161a13d | 679 | if (matching_host_key_dns) |
1432b5c4 | 680 | snprintf(msg2, sizeof(msg2), |
681 | "Matching host key fingerprint" | |
682 | " found in DNS.\n"); | |
683 | else | |
684 | snprintf(msg2, sizeof(msg2), | |
685 | "No matching host key fingerprint" | |
686 | " found in DNS.\n"); | |
687 | } | |
616a6b93 | 688 | snprintf(msg, sizeof(msg), |
f49bc4f7 | 689 | "The authenticity of host '%.200s (%s)' can't be " |
8a48a7ef | 690 | "established%s\n" |
1432b5c4 | 691 | "%s key fingerprint is %s.\n%s" |
f49bc4f7 | 692 | "Are you sure you want to continue connecting " |
8a48a7ef | 693 | "(yes/no)? ", |
1432b5c4 | 694 | host, ip, msg1, type, fp, msg2); |
22138a36 | 695 | xfree(fp); |
616a6b93 | 696 | if (!confirm(msg)) |
f49bc4f7 | 697 | goto fail; |
5260325f | 698 | } |
f49bc4f7 | 699 | /* |
700 | * If not in strict mode, add the key automatically to the | |
701 | * local known_hosts file. | |
702 | */ | |
e79276c2 | 703 | if (options.check_host_ip && ip_status == HOST_NEW) { |
704 | snprintf(hostline, sizeof(hostline), "%s,%s", | |
705 | host, ip); | |
706 | hostp = hostline; | |
707 | if (options.hash_known_hosts) { | |
708 | /* Add hash of host and IP separately */ | |
709 | r = add_host_to_hostfile(user_hostfile, host, | |
710 | host_key, options.hash_known_hosts) && | |
711 | add_host_to_hostfile(user_hostfile, ip, | |
712 | host_key, options.hash_known_hosts); | |
713 | } else { | |
714 | /* Add unhashed "host,ip" */ | |
715 | r = add_host_to_hostfile(user_hostfile, | |
716 | hostline, host_key, | |
717 | options.hash_known_hosts); | |
718 | } | |
719 | } else { | |
720 | r = add_host_to_hostfile(user_hostfile, host, host_key, | |
721 | options.hash_known_hosts); | |
722 | hostp = host; | |
723 | } | |
724 | ||
725 | if (!r) | |
bbe88b6d | 726 | logit("Failed to add the host to the list of known " |
f49bc4f7 | 727 | "hosts (%.500s).", user_hostfile); |
5260325f | 728 | else |
bbe88b6d | 729 | logit("Warning: Permanently added '%.200s' (%s) to the " |
f49bc4f7 | 730 | "list of known hosts.", hostp, type); |
5260325f | 731 | break; |
732 | case HOST_CHANGED: | |
733 | if (options.check_host_ip && host_ip_differ) { | |
ca75d7de | 734 | char *key_msg; |
5260325f | 735 | if (ip_status == HOST_NEW) |
ca75d7de | 736 | key_msg = "is unknown"; |
5260325f | 737 | else if (ip_status == HOST_OK) |
ca75d7de | 738 | key_msg = "is unchanged"; |
5260325f | 739 | else |
ca75d7de | 740 | key_msg = "has a different value"; |
5260325f | 741 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
742 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); | |
743 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1d1ffb87 | 744 | error("The %s host key for %s has changed,", type, host); |
5260325f | 745 | error("and the key for the according IP address %s", ip); |
ca75d7de | 746 | error("%s. This could either mean that", key_msg); |
5260325f | 747 | error("DNS SPOOFING is happening or the IP address for the host"); |
1e3b8b07 | 748 | error("and its host key have changed at the same time."); |
7c49df64 | 749 | if (ip_status != HOST_NEW) |
1e3b8b07 | 750 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
5260325f | 751 | } |
752 | /* The host key has changed. */ | |
1a1bc5d5 | 753 | warn_changed_key(host_key); |
5260325f | 754 | error("Add correct host key in %.100s to get rid of this message.", |
8abcdba4 | 755 | user_hostfile); |
1e3b8b07 | 756 | error("Offending key in %s:%d", host_file, host_line); |
5260325f | 757 | |
aa3378df | 758 | /* |
759 | * If strict host key checking is in use, the user will have | |
760 | * to edit the key manually and we can only abort. | |
761 | */ | |
f49bc4f7 | 762 | if (options.strict_host_key_checking) { |
763 | error("%s host key for %.200s has changed and you have " | |
764 | "requested strict checking.", type, host); | |
765 | goto fail; | |
766 | } | |
5260325f | 767 | |
aa3378df | 768 | /* |
769 | * If strict host key checking has not been requested, allow | |
d453a600 | 770 | * the connection but without MITM-able authentication or |
aa3378df | 771 | * agent forwarding. |
772 | */ | |
5260325f | 773 | if (options.password_authentication) { |
f49bc4f7 | 774 | error("Password authentication is disabled to avoid " |
775 | "man-in-the-middle attacks."); | |
5260325f | 776 | options.password_authentication = 0; |
777 | } | |
d453a600 | 778 | if (options.kbd_interactive_authentication) { |
779 | error("Keyboard-interactive authentication is disabled" | |
780 | " to avoid man-in-the-middle attacks."); | |
781 | options.kbd_interactive_authentication = 0; | |
782 | options.challenge_response_authentication = 0; | |
783 | } | |
784 | if (options.challenge_response_authentication) { | |
785 | error("Challenge/response authentication is disabled" | |
786 | " to avoid man-in-the-middle attacks."); | |
787 | options.challenge_response_authentication = 0; | |
788 | } | |
5260325f | 789 | if (options.forward_agent) { |
f49bc4f7 | 790 | error("Agent forwarding is disabled to avoid " |
791 | "man-in-the-middle attacks."); | |
5260325f | 792 | options.forward_agent = 0; |
793 | } | |
0b6fbf03 | 794 | if (options.forward_x11) { |
f49bc4f7 | 795 | error("X11 forwarding is disabled to avoid " |
796 | "man-in-the-middle attacks."); | |
0b6fbf03 | 797 | options.forward_x11 = 0; |
798 | } | |
f49bc4f7 | 799 | if (options.num_local_forwards > 0 || |
800 | options.num_remote_forwards > 0) { | |
801 | error("Port forwarding is disabled to avoid " | |
802 | "man-in-the-middle attacks."); | |
803 | options.num_local_forwards = | |
184eed6a | 804 | options.num_remote_forwards = 0; |
0b6fbf03 | 805 | } |
aa3378df | 806 | /* |
807 | * XXX Should permit the user to change to use the new id. | |
808 | * This could be done by converting the host key to an | |
809 | * identifying sentence, tell that the host identifies itself | |
810 | * by that sentence, and ask the user if he/she whishes to | |
811 | * accept the authentication. | |
812 | */ | |
5260325f | 813 | break; |
8a48a7ef | 814 | case HOST_FOUND: |
815 | fatal("internal error"); | |
816 | break; | |
5260325f | 817 | } |
0b6fbf03 | 818 | |
7c49df64 | 819 | if (options.check_host_ip && host_status != HOST_CHANGED && |
820 | ip_status == HOST_CHANGED) { | |
616a6b93 | 821 | snprintf(msg, sizeof(msg), |
822 | "Warning: the %s host key for '%.200s' " | |
823 | "differs from the key for the IP address '%.128s'" | |
824 | "\nOffending key for IP in %s:%d", | |
825 | type, host, ip, ip_file, ip_line); | |
826 | if (host_status == HOST_OK) { | |
827 | len = strlen(msg); | |
828 | snprintf(msg + len, sizeof(msg) - len, | |
829 | "\nMatching host key in %s:%d", | |
7203d6bb | 830 | host_file, host_line); |
616a6b93 | 831 | } |
7c49df64 | 832 | if (options.strict_host_key_checking == 1) { |
b0545fe6 | 833 | logit("%s", msg); |
f49bc4f7 | 834 | error("Exiting, you have requested strict checking."); |
835 | goto fail; | |
7c49df64 | 836 | } else if (options.strict_host_key_checking == 2) { |
616a6b93 | 837 | strlcat(msg, "\nAre you sure you want " |
838 | "to continue connecting (yes/no)? ", sizeof(msg)); | |
839 | if (!confirm(msg)) | |
f49bc4f7 | 840 | goto fail; |
616a6b93 | 841 | } else { |
b0545fe6 | 842 | logit("%s", msg); |
7c49df64 | 843 | } |
844 | } | |
845 | ||
0b6fbf03 | 846 | xfree(ip); |
f49bc4f7 | 847 | return 0; |
848 | ||
849 | fail: | |
850 | xfree(ip); | |
851 | return -1; | |
852 | } | |
853 | ||
21289cd0 | 854 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
f49bc4f7 | 855 | int |
856 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) | |
857 | { | |
858 | struct stat st; | |
0161a13d | 859 | int flags = 0; |
f49bc4f7 | 860 | |
0161a13d | 861 | if (options.verify_host_key_dns && |
862 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { | |
863 | ||
864 | if (flags & DNS_VERIFY_FOUND) { | |
865 | ||
866 | if (options.verify_host_key_dns == 1 && | |
867 | flags & DNS_VERIFY_MATCH && | |
868 | flags & DNS_VERIFY_SECURE) | |
869 | return 0; | |
870 | ||
871 | if (flags & DNS_VERIFY_MATCH) { | |
872 | matching_host_key_dns = 1; | |
873 | } else { | |
874 | warn_changed_key(host_key); | |
875 | error("Update the SSHFP RR in DNS with the new " | |
876 | "host key to get rid of this message."); | |
877 | } | |
21289cd0 | 878 | } |
879 | } | |
21289cd0 | 880 | |
f49bc4f7 | 881 | /* return ok if the key can be found in an old keyfile */ |
882 | if (stat(options.system_hostfile2, &st) == 0 || | |
883 | stat(options.user_hostfile2, &st) == 0) { | |
884 | if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, | |
885 | options.user_hostfile2, options.system_hostfile2) == 0) | |
886 | return 0; | |
887 | } | |
888 | return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, | |
889 | options.user_hostfile, options.system_hostfile); | |
95f1eccc | 890 | } |
891 | ||
8ce64345 | 892 | /* |
a306f2dd | 893 | * Starts a dialog with the server, and authenticates the current user on the |
894 | * server. This does not need any extra privileges. The basic connection | |
895 | * to the server must already have been established before this is called. | |
896 | * If login fails, this function prints an error and never returns. | |
897 | * This function does not require super-user privileges. | |
8ce64345 | 898 | */ |
899 | void | |
39c00dc2 | 900 | ssh_login(Sensitive *sensitive, const char *orighost, |
63bd8c36 | 901 | struct sockaddr *hostaddr, struct passwd *pw) |
8ce64345 | 902 | { |
a306f2dd | 903 | char *host, *cp; |
8ce64345 | 904 | char *server_user, *local_user; |
8ce64345 | 905 | |
8ce64345 | 906 | local_user = xstrdup(pw->pw_name); |
907 | server_user = options.user ? options.user : local_user; | |
908 | ||
7b2ea3a1 | 909 | /* Convert the user-supplied hostname into all lowercase. */ |
910 | host = xstrdup(orighost); | |
911 | for (cp = host; *cp; cp++) | |
912 | if (isupper(*cp)) | |
9555d258 | 913 | *cp = (char)tolower(*cp); |
7b2ea3a1 | 914 | |
915 | /* Exchange protocol version identification strings with the server. */ | |
916 | ssh_exchange_identification(); | |
917 | ||
918 | /* Put the connection into non-blocking mode. */ | |
919 | packet_set_nonblocking(); | |
920 | ||
7b2ea3a1 | 921 | /* key exchange */ |
7b2ea3a1 | 922 | /* authenticate user */ |
8ce64345 | 923 | if (compat20) { |
924 | ssh_kex2(host, hostaddr); | |
39c00dc2 | 925 | ssh_userauth2(local_user, server_user, host, sensitive); |
8ce64345 | 926 | } else { |
8ce64345 | 927 | ssh_kex(host, hostaddr); |
39c00dc2 | 928 | ssh_userauth1(local_user, server_user, host, sensitive); |
8ce64345 | 929 | } |
2b8dc5e3 | 930 | xfree(local_user); |
7b2ea3a1 | 931 | } |
0ae4fe1d | 932 | |
933 | void | |
934 | ssh_put_password(char *password) | |
935 | { | |
936 | int size; | |
937 | char *padded; | |
938 | ||
99c415db | 939 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
449c5ba5 | 940 | packet_put_cstring(password); |
99c415db | 941 | return; |
942 | } | |
0ae4fe1d | 943 | size = roundup(strlen(password) + 1, 32); |
52e3daed | 944 | padded = xcalloc(1, size); |
0ae4fe1d | 945 | strlcpy(padded, password, size); |
946 | packet_put_string(padded, size); | |
947 | memset(padded, 0, size); | |
948 | xfree(padded); | |
949 | } | |
8a48a7ef | 950 | |
951 | static int | |
952 | show_key_from_file(const char *file, const char *host, int keytype) | |
953 | { | |
954 | Key *found; | |
955 | char *fp; | |
956 | int line, ret; | |
957 | ||
958 | found = key_new(keytype); | |
959 | if ((ret = lookup_key_in_hostfile_by_type(file, host, | |
960 | keytype, found, &line))) { | |
961 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); | |
bbe88b6d | 962 | logit("WARNING: %s key found for host %s\n" |
567a05bf | 963 | "in %s:%d\n" |
8a48a7ef | 964 | "%s key fingerprint %s.", |
965 | key_type(found), host, file, line, | |
966 | key_type(found), fp); | |
967 | xfree(fp); | |
968 | } | |
969 | key_free(found); | |
970 | return (ret); | |
971 | } | |
972 | ||
973 | /* print all known host keys for a given host, but skip keys of given type */ | |
974 | static int | |
975 | show_other_keys(const char *host, Key *key) | |
976 | { | |
977 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; | |
978 | int i, found = 0; | |
979 | ||
980 | for (i = 0; type[i] != -1; i++) { | |
981 | if (type[i] == key->type) | |
982 | continue; | |
983 | if (type[i] != KEY_RSA1 && | |
984 | show_key_from_file(options.user_hostfile2, host, type[i])) { | |
985 | found = 1; | |
986 | continue; | |
987 | } | |
988 | if (type[i] != KEY_RSA1 && | |
989 | show_key_from_file(options.system_hostfile2, host, type[i])) { | |
990 | found = 1; | |
991 | continue; | |
992 | } | |
993 | if (show_key_from_file(options.user_hostfile, host, type[i])) { | |
994 | found = 1; | |
995 | continue; | |
996 | } | |
997 | if (show_key_from_file(options.system_hostfile, host, type[i])) { | |
998 | found = 1; | |
999 | continue; | |
1000 | } | |
1001 | debug2("no key of type %d for host %s", type[i], host); | |
1002 | } | |
1003 | return (found); | |
1004 | } | |
1a1bc5d5 | 1005 | |
1006 | static void | |
1007 | warn_changed_key(Key *host_key) | |
1008 | { | |
1009 | char *fp; | |
f5da7f70 | 1010 | const char *type = key_type(host_key); |
1a1bc5d5 | 1011 | |
1012 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); | |
1013 | ||
1014 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1015 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); | |
1016 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1017 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); | |
1018 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); | |
1019 | error("It is also possible that the %s host key has just been changed.", type); | |
1020 | error("The fingerprint for the %s key sent by the remote host is\n%s.", | |
1021 | type, fp); | |
1022 | error("Please contact your system administrator."); | |
1023 | ||
1024 | xfree(fp); | |
1a1bc5d5 | 1025 | } |
d20f3c9e | 1026 | |
1027 | /* | |
1028 | * Execute a local command | |
1029 | */ | |
1030 | int | |
1031 | ssh_local_cmd(const char *args) | |
1032 | { | |
1033 | char *shell; | |
1034 | pid_t pid; | |
1035 | int status; | |
1036 | ||
1037 | if (!options.permit_local_command || | |
1038 | args == NULL || !*args) | |
1039 | return (1); | |
1040 | ||
1041 | if ((shell = getenv("SHELL")) == NULL) | |
1042 | shell = _PATH_BSHELL; | |
1043 | ||
1044 | pid = fork(); | |
1045 | if (pid == 0) { | |
1046 | debug3("Executing %s -c \"%s\"", shell, args); | |
1047 | execl(shell, shell, "-c", args, (char *)NULL); | |
1048 | error("Couldn't execute %s -c \"%s\": %s", | |
1049 | shell, args, strerror(errno)); | |
1050 | _exit(1); | |
1051 | } else if (pid == -1) | |
1052 | fatal("fork failed: %.100s", strerror(errno)); | |
1053 | while (waitpid(pid, &status, 0) == -1) | |
1054 | if (errno != EINTR) | |
1055 | fatal("Couldn't wait for child: %s", strerror(errno)); | |
1056 | ||
1057 | if (!WIFEXITED(status)) | |
1058 | return (1); | |
1059 | ||
1060 | return (WEXITSTATUS(status)); | |
1061 | } |