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4439dde1 | 1 | /* $OpenBSD: sshconnect.c,v 1.181 2006/04/20 09:47:59 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. */ | |
3fb156df | 100 | seteuid(original_real_uid); |
101 | setuid(original_real_uid); | |
5260325f | 102 | |
103 | /* Redirect stdin and stdout. */ | |
104 | close(pin[1]); | |
105 | if (pin[0] != 0) { | |
106 | if (dup2(pin[0], 0) < 0) | |
107 | perror("dup2 stdin"); | |
108 | close(pin[0]); | |
109 | } | |
110 | close(pout[0]); | |
111 | if (dup2(pout[1], 1) < 0) | |
112 | perror("dup2 stdout"); | |
113 | /* Cannot be 1 because pin allocated two descriptors. */ | |
114 | close(pout[1]); | |
115 | ||
116 | /* Stderr is left as it is so that error messages get | |
117 | printed on the user's terminal. */ | |
30228d7c | 118 | argv[0] = _PATH_BSHELL; |
5260325f | 119 | argv[1] = "-c"; |
120 | argv[2] = command_string; | |
121 | argv[3] = NULL; | |
122 | ||
123 | /* Execute the proxy command. Note that we gave up any | |
124 | extra privileges above. */ | |
328654d8 | 125 | execv(argv[0], argv); |
126 | perror(argv[0]); | |
5260325f | 127 | exit(1); |
8efc0c15 | 128 | } |
5260325f | 129 | /* Parent. */ |
130 | if (pid < 0) | |
131 | fatal("fork failed: %.100s", strerror(errno)); | |
6939bbd4 | 132 | else |
133 | proxy_command_pid = pid; /* save pid to clean up later */ | |
5260325f | 134 | |
135 | /* Close child side of the descriptors. */ | |
136 | close(pin[0]); | |
137 | close(pout[1]); | |
138 | ||
139 | /* Free the command name. */ | |
a980cbd7 | 140 | xfree(command_string); |
5260325f | 141 | |
142 | /* Set the connection file descriptors. */ | |
143 | packet_set_connection(pout[0], pin[1]); | |
8efc0c15 | 144 | |
ce773142 | 145 | /* Indicate OK return */ |
146 | return 0; | |
5260325f | 147 | } |
8efc0c15 | 148 | |
5260325f | 149 | /* |
150 | * Creates a (possibly privileged) socket for use as the ssh connection. | |
151 | */ | |
396c147e | 152 | static int |
3e131a6d | 153 | ssh_create_socket(int privileged, struct addrinfo *ai) |
8efc0c15 | 154 | { |
3435f5a6 | 155 | int sock, gaierr; |
156 | struct addrinfo hints, *res; | |
5260325f | 157 | |
aa3378df | 158 | /* |
159 | * If we are running as root and want to connect to a privileged | |
160 | * port, bind our own socket to a privileged port. | |
161 | */ | |
5260325f | 162 | if (privileged) { |
163 | int p = IPPORT_RESERVED - 1; | |
3fb156df | 164 | PRIV_START; |
3e131a6d | 165 | sock = rresvport_af(&p, ai->ai_family); |
3fb156df | 166 | PRIV_END; |
5260325f | 167 | if (sock < 0) |
3e131a6d | 168 | error("rresvport: af=%d %.100s", ai->ai_family, |
169 | strerror(errno)); | |
c8d54615 | 170 | else |
171 | debug("Allocated local port %d.", p); | |
3435f5a6 | 172 | return sock; |
173 | } | |
3e131a6d | 174 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3435f5a6 | 175 | if (sock < 0) |
176 | error("socket: %.100s", strerror(errno)); | |
3435f5a6 | 177 | |
178 | /* Bind the socket to an alternative local IP address */ | |
179 | if (options.bind_address == NULL) | |
180 | return sock; | |
181 | ||
182 | memset(&hints, 0, sizeof(hints)); | |
3e131a6d | 183 | hints.ai_family = ai->ai_family; |
184 | hints.ai_socktype = ai->ai_socktype; | |
185 | hints.ai_protocol = ai->ai_protocol; | |
3435f5a6 | 186 | hints.ai_flags = AI_PASSIVE; |
187 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); | |
188 | if (gaierr) { | |
189 | error("getaddrinfo: %s: %s", options.bind_address, | |
190 | gai_strerror(gaierr)); | |
191 | close(sock); | |
192 | return -1; | |
193 | } | |
194 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { | |
195 | error("bind: %s: %s", options.bind_address, strerror(errno)); | |
196 | close(sock); | |
197 | freeaddrinfo(res); | |
198 | return -1; | |
5260325f | 199 | } |
3435f5a6 | 200 | freeaddrinfo(res); |
5260325f | 201 | return sock; |
8efc0c15 | 202 | } |
203 | ||
09ab3296 | 204 | static int |
205 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, | |
206 | socklen_t addrlen, int timeout) | |
207 | { | |
208 | fd_set *fdset; | |
209 | struct timeval tv; | |
210 | socklen_t optlen; | |
52e3daed | 211 | int optval, rc, result = -1; |
09ab3296 | 212 | |
213 | if (timeout <= 0) | |
214 | return (connect(sockfd, serv_addr, addrlen)); | |
215 | ||
2daf1db1 | 216 | set_nonblock(sockfd); |
09ab3296 | 217 | rc = connect(sockfd, serv_addr, addrlen); |
2daf1db1 | 218 | if (rc == 0) { |
219 | unset_nonblock(sockfd); | |
09ab3296 | 220 | return (0); |
2daf1db1 | 221 | } |
09ab3296 | 222 | if (errno != EINPROGRESS) |
223 | return (-1); | |
224 | ||
52e3daed | 225 | fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS), |
226 | sizeof(fd_mask)); | |
09ab3296 | 227 | FD_SET(sockfd, fdset); |
228 | tv.tv_sec = timeout; | |
229 | tv.tv_usec = 0; | |
230 | ||
f8cc7664 | 231 | for (;;) { |
09ab3296 | 232 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
233 | if (rc != -1 || errno != EINTR) | |
234 | break; | |
235 | } | |
236 | ||
f8cc7664 | 237 | switch (rc) { |
09ab3296 | 238 | case 0: |
239 | /* Timed out */ | |
240 | errno = ETIMEDOUT; | |
da54f5be | 241 | break; |
09ab3296 | 242 | case -1: |
243 | /* Select error */ | |
aff51935 | 244 | debug("select: %s", strerror(errno)); |
da54f5be | 245 | break; |
09ab3296 | 246 | case 1: |
247 | /* Completed or failed */ | |
248 | optval = 0; | |
249 | optlen = sizeof(optval); | |
aff51935 | 250 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
ce26c02a | 251 | &optlen) == -1) { |
aff51935 | 252 | debug("getsockopt: %s", strerror(errno)); |
da54f5be | 253 | break; |
ce26c02a | 254 | } |
09ab3296 | 255 | if (optval != 0) { |
256 | errno = optval; | |
da54f5be | 257 | break; |
09ab3296 | 258 | } |
da54f5be | 259 | result = 0; |
2daf1db1 | 260 | unset_nonblock(sockfd); |
09ab3296 | 261 | break; |
262 | default: | |
263 | /* Should not occur */ | |
264 | fatal("Bogus return (%d) from select()", rc); | |
265 | } | |
266 | ||
da54f5be | 267 | xfree(fdset); |
268 | return (result); | |
09ab3296 | 269 | } |
270 | ||
5260325f | 271 | /* |
48e671d5 | 272 | * Opens a TCP/IP connection to the remote server on the given host. |
273 | * The address of the remote host will be returned in hostaddr. | |
3fb156df | 274 | * If port is 0, the default port will be used. If needpriv is true, |
5260325f | 275 | * a privileged port will be allocated to make the connection. |
3fb156df | 276 | * This requires super-user privileges if needpriv is true. |
5260325f | 277 | * Connection_attempts specifies the maximum number of tries (one per |
278 | * second). If proxy_command is non-NULL, it specifies the command (with %h | |
279 | * and %p substituted for host and port, respectively) to use to contact | |
280 | * the daemon. | |
281 | */ | |
282 | int | |
48e671d5 | 283 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
dab89049 | 284 | u_short port, int family, int connection_attempts, |
3fb156df | 285 | int needpriv, const char *proxy_command) |
8efc0c15 | 286 | { |
b5c334cc | 287 | int gaierr; |
288 | int on = 1; | |
48e671d5 | 289 | int sock = -1, attempt; |
48e671d5 | 290 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
b5c334cc | 291 | struct addrinfo hints, *ai, *aitop; |
5260325f | 292 | |
a77673cc | 293 | debug2("ssh_connect: needpriv %d", needpriv); |
5260325f | 294 | |
5260325f | 295 | /* If a proxy command is given, connect using it. */ |
296 | if (proxy_command != NULL) | |
3fb156df | 297 | return ssh_proxy_connect(host, port, proxy_command); |
5260325f | 298 | |
299 | /* No proxy command. */ | |
300 | ||
48e671d5 | 301 | memset(&hints, 0, sizeof(hints)); |
dab89049 | 302 | hints.ai_family = family; |
48e671d5 | 303 | hints.ai_socktype = SOCK_STREAM; |
d6133f43 | 304 | snprintf(strport, sizeof strport, "%u", port); |
48e671d5 | 305 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
306 | fatal("%s: %.100s: %s", __progname, host, | |
307 | gai_strerror(gaierr)); | |
5260325f | 308 | |
4439dde1 | 309 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
5260325f | 310 | if (attempt > 0) |
311 | debug("Trying again..."); | |
312 | ||
4439dde1 | 313 | /* |
314 | * Loop through addresses for this host, and try each one in | |
315 | * sequence until the connection succeeds. | |
316 | */ | |
48e671d5 | 317 | for (ai = aitop; ai; ai = ai->ai_next) { |
318 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
319 | continue; | |
320 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
321 | ntop, sizeof(ntop), strport, sizeof(strport), | |
322 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
323 | error("ssh_connect: getnameinfo failed"); | |
324 | continue; | |
325 | } | |
326 | debug("Connecting to %.200s [%.100s] port %s.", | |
327 | host, ntop, strport); | |
328 | ||
329 | /* Create a socket for connecting. */ | |
3e131a6d | 330 | sock = ssh_create_socket(needpriv, ai); |
48e671d5 | 331 | if (sock < 0) |
ce773142 | 332 | /* Any error is already output */ |
48e671d5 | 333 | continue; |
334 | ||
09ab3296 | 335 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
336 | options.connection_timeout) >= 0) { | |
48e671d5 | 337 | /* Successful connection. */ |
cd332296 | 338 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
5260325f | 339 | break; |
48e671d5 | 340 | } else { |
c750d869 | 341 | debug("connect to address %s port %s: %s", |
342 | ntop, strport, strerror(errno)); | |
5260325f | 343 | close(sock); |
4439dde1 | 344 | sock = -1; |
5260325f | 345 | } |
8efc0c15 | 346 | } |
4439dde1 | 347 | if (sock != -1) |
48e671d5 | 348 | break; /* Successful connection. */ |
8efc0c15 | 349 | |
5260325f | 350 | /* Sleep a moment before retrying. */ |
351 | sleep(1); | |
352 | } | |
48e671d5 | 353 | |
354 | freeaddrinfo(aitop); | |
355 | ||
5260325f | 356 | /* Return failure if we didn't get a successful connection. */ |
4439dde1 | 357 | if (sock == -1) { |
cf039bd1 | 358 | error("ssh: connect to host %s port %s: %s", |
9bd68577 | 359 | host, strport, strerror(errno)); |
cf039bd1 | 360 | return (-1); |
9bd68577 | 361 | } |
8efc0c15 | 362 | |
5260325f | 363 | debug("Connection established."); |
8efc0c15 | 364 | |
fd573618 | 365 | /* Set SO_KEEPALIVE if requested. */ |
366 | if (options.tcp_keep_alive && | |
b5c334cc | 367 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
368 | sizeof(on)) < 0) | |
369 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
8efc0c15 | 370 | |
5260325f | 371 | /* Set the connection. */ |
372 | packet_set_connection(sock, sock); | |
8efc0c15 | 373 | |
ce773142 | 374 | return 0; |
8efc0c15 | 375 | } |
376 | ||
5260325f | 377 | /* |
378 | * Waits for the server identification string, and sends our own | |
379 | * identification string. | |
380 | */ | |
396c147e | 381 | static void |
5ca51e19 | 382 | ssh_exchange_identification(void) |
8efc0c15 | 383 | { |
5260325f | 384 | char buf[256], remote_version[256]; /* must be same size! */ |
2ceb8101 | 385 | int remote_major, remote_minor, mismatch; |
5260325f | 386 | int connection_in = packet_get_connection_in(); |
387 | int connection_out = packet_get_connection_out(); | |
2b87da3b | 388 | int minor1 = PROTOCOL_MINOR_1; |
2ceb8101 | 389 | u_int i; |
5260325f | 390 | |
05624c18 | 391 | /* Read other side's version identification. */ |
38c295d6 | 392 | for (;;) { |
393 | for (i = 0; i < sizeof(buf) - 1; i++) { | |
05624c18 | 394 | size_t len = atomicio(read, connection_in, &buf[i], 1); |
395 | ||
56964485 | 396 | if (len != 1 && errno == EPIPE) |
38c295d6 | 397 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
05624c18 | 398 | else if (len != 1) |
399 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); | |
38c295d6 | 400 | if (buf[i] == '\r') { |
401 | buf[i] = '\n'; | |
402 | buf[i + 1] = 0; | |
403 | continue; /**XXX wait for \n */ | |
404 | } | |
405 | if (buf[i] == '\n') { | |
406 | buf[i + 1] = 0; | |
407 | break; | |
408 | } | |
5260325f | 409 | } |
38c295d6 | 410 | buf[sizeof(buf) - 1] = 0; |
411 | if (strncmp(buf, "SSH-", 4) == 0) | |
5260325f | 412 | break; |
38c295d6 | 413 | debug("ssh_exchange_identification: %s", buf); |
8efc0c15 | 414 | } |
8ce64345 | 415 | server_version_string = xstrdup(buf); |
5260325f | 416 | |
aa3378df | 417 | /* |
418 | * Check that the versions match. In future this might accept | |
419 | * several versions and set appropriate flags to handle them. | |
420 | */ | |
8ce64345 | 421 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
422 | &remote_major, &remote_minor, remote_version) != 3) | |
5260325f | 423 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
424 | debug("Remote protocol version %d.%d, remote software version %.100s", | |
184eed6a | 425 | remote_major, remote_minor, remote_version); |
5260325f | 426 | |
8ce64345 | 427 | compat_datafellows(remote_version); |
a8be9f80 | 428 | mismatch = 0; |
429 | ||
6aacefa7 | 430 | switch (remote_major) { |
a8be9f80 | 431 | case 1: |
432 | if (remote_minor == 99 && | |
433 | (options.protocol & SSH_PROTO_2) && | |
434 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { | |
435 | enable_compat20(); | |
436 | break; | |
5260325f | 437 | } |
a8be9f80 | 438 | if (!(options.protocol & SSH_PROTO_1)) { |
439 | mismatch = 1; | |
440 | break; | |
441 | } | |
442 | if (remote_minor < 3) { | |
443 | fatal("Remote machine has too old SSH software version."); | |
fa08c86b | 444 | } else if (remote_minor == 3 || remote_minor == 4) { |
a8be9f80 | 445 | /* We speak 1.3, too. */ |
446 | enable_compat13(); | |
fa08c86b | 447 | minor1 = 3; |
a8be9f80 | 448 | if (options.forward_agent) { |
bbe88b6d | 449 | logit("Agent forwarding disabled for protocol 1.3"); |
a8be9f80 | 450 | options.forward_agent = 0; |
451 | } | |
452 | } | |
453 | break; | |
454 | case 2: | |
455 | if (options.protocol & SSH_PROTO_2) { | |
456 | enable_compat20(); | |
457 | break; | |
458 | } | |
459 | /* FALLTHROUGH */ | |
6ae2364d | 460 | default: |
a8be9f80 | 461 | mismatch = 1; |
462 | break; | |
8efc0c15 | 463 | } |
a8be9f80 | 464 | if (mismatch) |
5260325f | 465 | fatal("Protocol major versions differ: %d vs. %d", |
a8be9f80 | 466 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
467 | remote_major); | |
5260325f | 468 | /* Send our own protocol version identification. */ |
469 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | |
a8be9f80 | 470 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
fa08c86b | 471 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
8ce64345 | 472 | SSH_VERSION); |
dc54438a | 473 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
5260325f | 474 | fatal("write: %.100s", strerror(errno)); |
8ce64345 | 475 | client_version_string = xstrdup(buf); |
476 | chop(client_version_string); | |
477 | chop(server_version_string); | |
478 | debug("Local version string %.100s", client_version_string); | |
8efc0c15 | 479 | } |
480 | ||
f21032a6 | 481 | /* defaults to 'no' */ |
396c147e | 482 | static int |
a2c92c4a | 483 | confirm(const char *prompt) |
8efc0c15 | 484 | { |
616a6b93 | 485 | const char *msg, *again = "Please type 'yes' or 'no': "; |
486 | char *p; | |
487 | int ret = -1; | |
5260325f | 488 | |
f21032a6 | 489 | if (options.batch_mode) |
490 | return 0; | |
616a6b93 | 491 | for (msg = prompt;;msg = again) { |
492 | p = read_passphrase(msg, RP_ECHO); | |
493 | if (p == NULL || | |
494 | (p[0] == '\0') || (p[0] == '\n') || | |
495 | strncasecmp(p, "no", 2) == 0) | |
496 | ret = 0; | |
f11fe301 | 497 | if (p && strncasecmp(p, "yes", 3) == 0) |
616a6b93 | 498 | ret = 1; |
499 | if (p) | |
500 | xfree(p); | |
501 | if (ret != -1) | |
502 | return ret; | |
8efc0c15 | 503 | } |
8efc0c15 | 504 | } |
505 | ||
5260325f | 506 | /* |
f49bc4f7 | 507 | * check whether the supplied host key is valid, return -1 if the key |
508 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. | |
5260325f | 509 | */ |
396c147e | 510 | static int |
a306f2dd | 511 | check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, |
f49bc4f7 | 512 | int readonly, const char *user_hostfile, const char *system_hostfile) |
8efc0c15 | 513 | { |
4fe2af09 | 514 | Key *file_key; |
b6c7b7b7 | 515 | const char *type = key_type(host_key); |
95f1eccc | 516 | char *ip = NULL; |
22138a36 | 517 | char hostline[1000], *hostp, *fp; |
5260325f | 518 | HostStatus host_status; |
519 | HostStatus ip_status; | |
e79276c2 | 520 | int r, local = 0, host_ip_differ = 0; |
20af321f | 521 | int salen; |
48e671d5 | 522 | char ntop[NI_MAXHOST]; |
616a6b93 | 523 | char msg[1024]; |
1432b5c4 | 524 | int len, host_line, ip_line; |
1e3b8b07 | 525 | const char *host_file = NULL, *ip_file = NULL; |
48e671d5 | 526 | |
527 | /* | |
528 | * Force accepting of the host key for loopback/localhost. The | |
529 | * problem is that if the home directory is NFS-mounted to multiple | |
530 | * machines, localhost will refer to a different machine in each of | |
531 | * them, and the user will get bogus HOST_CHANGED warnings. This | |
532 | * essentially disables host authentication for localhost; however, | |
533 | * this is probably not a real problem. | |
534 | */ | |
a306f2dd | 535 | /** hostaddr == 0! */ |
48e671d5 | 536 | switch (hostaddr->sa_family) { |
537 | case AF_INET: | |
f49bc4f7 | 538 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
4e2e5cfd | 539 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
20af321f | 540 | salen = sizeof(struct sockaddr_in); |
48e671d5 | 541 | break; |
542 | case AF_INET6: | |
f49bc4f7 | 543 | local = IN6_IS_ADDR_LOOPBACK( |
544 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | |
20af321f | 545 | salen = sizeof(struct sockaddr_in6); |
48e671d5 | 546 | break; |
547 | default: | |
548 | local = 0; | |
20af321f | 549 | salen = sizeof(struct sockaddr_storage); |
48e671d5 | 550 | break; |
551 | } | |
8bbc048a | 552 | if (options.no_host_authentication_for_localhost == 1 && local && |
553 | options.host_key_alias == NULL) { | |
7c49df64 | 554 | debug("Forcing accepting of host key for " |
555 | "loopback/localhost."); | |
f49bc4f7 | 556 | return 0; |
48e671d5 | 557 | } |
5260325f | 558 | |
57112b5a | 559 | /* |
7c49df64 | 560 | * We don't have the remote ip-address for connections |
561 | * using a proxy command | |
562 | */ | |
563 | if (options.proxy_command == NULL) { | |
564 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), | |
565 | NULL, 0, NI_NUMERICHOST) != 0) | |
566 | fatal("check_host_key: getnameinfo failed"); | |
567 | ip = xstrdup(ntop); | |
568 | } else { | |
569 | ip = xstrdup("<no hostip for proxy command>"); | |
570 | } | |
571 | /* | |
572 | * Turn off check_host_ip if the connection is to localhost, via proxy | |
573 | * command or if we don't have a hostname to compare with | |
57112b5a | 574 | */ |
7c49df64 | 575 | if (options.check_host_ip && |
576 | (local || strcmp(host, ip) == 0 || options.proxy_command != NULL)) | |
57112b5a | 577 | options.check_host_ip = 0; |
578 | ||
8abcdba4 | 579 | /* |
7c49df64 | 580 | * Allow the user to record the key under a different name. This is |
8abcdba4 | 581 | * useful for ssh tunneling over forwarded connections or if you run |
7c49df64 | 582 | * multiple sshd's on different ports on the same machine. |
8abcdba4 | 583 | */ |
584 | if (options.host_key_alias != NULL) { | |
585 | host = options.host_key_alias; | |
586 | debug("using hostkeyalias: %s", host); | |
587 | } | |
588 | ||
95f1eccc | 589 | /* |
590 | * Store the host key from the known host file in here so that we can | |
591 | * compare it with the key for the IP address. | |
592 | */ | |
4fe2af09 | 593 | file_key = key_new(host_key->type); |
5260325f | 594 | |
aa3378df | 595 | /* |
7b9b0103 | 596 | * Check if the host key is present in the user's list of known |
aa3378df | 597 | * hosts or in the systemwide list. |
598 | */ | |
1e3b8b07 | 599 | host_file = user_hostfile; |
f49bc4f7 | 600 | host_status = check_host_in_hostfile(host_file, host, host_key, |
184eed6a | 601 | file_key, &host_line); |
1e3b8b07 | 602 | if (host_status == HOST_NEW) { |
603 | host_file = system_hostfile; | |
f49bc4f7 | 604 | host_status = check_host_in_hostfile(host_file, host, host_key, |
605 | file_key, &host_line); | |
1e3b8b07 | 606 | } |
aa3378df | 607 | /* |
608 | * Also perform check for the ip address, skip the check if we are | |
609 | * localhost or the hostname was an ip address to begin with | |
610 | */ | |
7c49df64 | 611 | if (options.check_host_ip) { |
4fe2af09 | 612 | Key *ip_key = key_new(host_key->type); |
5260325f | 613 | |
1e3b8b07 | 614 | ip_file = user_hostfile; |
f49bc4f7 | 615 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
616 | ip_key, &ip_line); | |
1e3b8b07 | 617 | if (ip_status == HOST_NEW) { |
618 | ip_file = system_hostfile; | |
f49bc4f7 | 619 | ip_status = check_host_in_hostfile(ip_file, ip, |
620 | host_key, ip_key, &ip_line); | |
1e3b8b07 | 621 | } |
5260325f | 622 | if (host_status == HOST_CHANGED && |
4fe2af09 | 623 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
5260325f | 624 | host_ip_differ = 1; |
625 | ||
4fe2af09 | 626 | key_free(ip_key); |
5260325f | 627 | } else |
628 | ip_status = host_status; | |
629 | ||
4fe2af09 | 630 | key_free(file_key); |
5260325f | 631 | |
632 | switch (host_status) { | |
633 | case HOST_OK: | |
634 | /* The host is known and the key matches. */ | |
1d1ffb87 | 635 | debug("Host '%.200s' is known and matches the %s host key.", |
636 | host, type); | |
1e3b8b07 | 637 | debug("Found key in %s:%d", host_file, host_line); |
7c49df64 | 638 | if (options.check_host_ip && ip_status == HOST_NEW) { |
f49bc4f7 | 639 | if (readonly) |
bbe88b6d | 640 | logit("%s host key for IP address " |
f49bc4f7 | 641 | "'%.128s' not in list of known hosts.", |
7c49df64 | 642 | type, ip); |
f49bc4f7 | 643 | else if (!add_host_to_hostfile(user_hostfile, ip, |
5c63c2ab | 644 | host_key, options.hash_known_hosts)) |
bbe88b6d | 645 | logit("Failed to add the %s host key for IP " |
f49bc4f7 | 646 | "address '%.128s' to the list of known " |
647 | "hosts (%.30s).", type, ip, user_hostfile); | |
648 | else | |
bbe88b6d | 649 | logit("Warning: Permanently added the %s host " |
f49bc4f7 | 650 | "key for IP address '%.128s' to the list " |
651 | "of known hosts.", type, ip); | |
5260325f | 652 | } |
653 | break; | |
654 | case HOST_NEW: | |
f49bc4f7 | 655 | if (readonly) |
656 | goto fail; | |
5260325f | 657 | /* The host is new. */ |
658 | if (options.strict_host_key_checking == 1) { | |
f49bc4f7 | 659 | /* |
660 | * User has requested strict host key checking. We | |
661 | * will not add the host key automatically. The only | |
662 | * alternative left is to abort. | |
663 | */ | |
664 | error("No %s host key is known for %.200s and you " | |
665 | "have requested strict checking.", type, host); | |
666 | goto fail; | |
5260325f | 667 | } else if (options.strict_host_key_checking == 2) { |
1432b5c4 | 668 | char msg1[1024], msg2[1024]; |
669 | ||
670 | if (show_other_keys(host, host_key)) | |
671 | snprintf(msg1, sizeof(msg1), | |
4e2e5cfd | 672 | "\nbut keys of different type are already" |
673 | " known for this host."); | |
1432b5c4 | 674 | else |
675 | snprintf(msg1, sizeof(msg1), "."); | |
5260325f | 676 | /* The default */ |
22138a36 | 677 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
1432b5c4 | 678 | msg2[0] = '\0'; |
1432b5c4 | 679 | if (options.verify_host_key_dns) { |
0161a13d | 680 | if (matching_host_key_dns) |
1432b5c4 | 681 | snprintf(msg2, sizeof(msg2), |
682 | "Matching host key fingerprint" | |
683 | " found in DNS.\n"); | |
684 | else | |
685 | snprintf(msg2, sizeof(msg2), | |
686 | "No matching host key fingerprint" | |
687 | " found in DNS.\n"); | |
688 | } | |
616a6b93 | 689 | snprintf(msg, sizeof(msg), |
f49bc4f7 | 690 | "The authenticity of host '%.200s (%s)' can't be " |
8a48a7ef | 691 | "established%s\n" |
1432b5c4 | 692 | "%s key fingerprint is %s.\n%s" |
f49bc4f7 | 693 | "Are you sure you want to continue connecting " |
8a48a7ef | 694 | "(yes/no)? ", |
1432b5c4 | 695 | host, ip, msg1, type, fp, msg2); |
22138a36 | 696 | xfree(fp); |
616a6b93 | 697 | if (!confirm(msg)) |
f49bc4f7 | 698 | goto fail; |
5260325f | 699 | } |
f49bc4f7 | 700 | /* |
701 | * If not in strict mode, add the key automatically to the | |
702 | * local known_hosts file. | |
703 | */ | |
e79276c2 | 704 | if (options.check_host_ip && ip_status == HOST_NEW) { |
705 | snprintf(hostline, sizeof(hostline), "%s,%s", | |
706 | host, ip); | |
707 | hostp = hostline; | |
708 | if (options.hash_known_hosts) { | |
709 | /* Add hash of host and IP separately */ | |
710 | r = add_host_to_hostfile(user_hostfile, host, | |
711 | host_key, options.hash_known_hosts) && | |
712 | add_host_to_hostfile(user_hostfile, ip, | |
713 | host_key, options.hash_known_hosts); | |
714 | } else { | |
715 | /* Add unhashed "host,ip" */ | |
716 | r = add_host_to_hostfile(user_hostfile, | |
717 | hostline, host_key, | |
718 | options.hash_known_hosts); | |
719 | } | |
720 | } else { | |
721 | r = add_host_to_hostfile(user_hostfile, host, host_key, | |
722 | options.hash_known_hosts); | |
723 | hostp = host; | |
724 | } | |
725 | ||
726 | if (!r) | |
bbe88b6d | 727 | logit("Failed to add the host to the list of known " |
f49bc4f7 | 728 | "hosts (%.500s).", user_hostfile); |
5260325f | 729 | else |
bbe88b6d | 730 | logit("Warning: Permanently added '%.200s' (%s) to the " |
f49bc4f7 | 731 | "list of known hosts.", hostp, type); |
5260325f | 732 | break; |
733 | case HOST_CHANGED: | |
734 | if (options.check_host_ip && host_ip_differ) { | |
ca75d7de | 735 | char *key_msg; |
5260325f | 736 | if (ip_status == HOST_NEW) |
ca75d7de | 737 | key_msg = "is unknown"; |
5260325f | 738 | else if (ip_status == HOST_OK) |
ca75d7de | 739 | key_msg = "is unchanged"; |
5260325f | 740 | else |
ca75d7de | 741 | key_msg = "has a different value"; |
5260325f | 742 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
743 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); | |
744 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1d1ffb87 | 745 | error("The %s host key for %s has changed,", type, host); |
5260325f | 746 | error("and the key for the according IP address %s", ip); |
ca75d7de | 747 | error("%s. This could either mean that", key_msg); |
5260325f | 748 | error("DNS SPOOFING is happening or the IP address for the host"); |
1e3b8b07 | 749 | error("and its host key have changed at the same time."); |
7c49df64 | 750 | if (ip_status != HOST_NEW) |
1e3b8b07 | 751 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
5260325f | 752 | } |
753 | /* The host key has changed. */ | |
1a1bc5d5 | 754 | warn_changed_key(host_key); |
5260325f | 755 | error("Add correct host key in %.100s to get rid of this message.", |
8abcdba4 | 756 | user_hostfile); |
1e3b8b07 | 757 | error("Offending key in %s:%d", host_file, host_line); |
5260325f | 758 | |
aa3378df | 759 | /* |
760 | * If strict host key checking is in use, the user will have | |
761 | * to edit the key manually and we can only abort. | |
762 | */ | |
f49bc4f7 | 763 | if (options.strict_host_key_checking) { |
764 | error("%s host key for %.200s has changed and you have " | |
765 | "requested strict checking.", type, host); | |
766 | goto fail; | |
767 | } | |
5260325f | 768 | |
aa3378df | 769 | /* |
770 | * If strict host key checking has not been requested, allow | |
d453a600 | 771 | * the connection but without MITM-able authentication or |
aa3378df | 772 | * agent forwarding. |
773 | */ | |
5260325f | 774 | if (options.password_authentication) { |
f49bc4f7 | 775 | error("Password authentication is disabled to avoid " |
776 | "man-in-the-middle attacks."); | |
5260325f | 777 | options.password_authentication = 0; |
778 | } | |
d453a600 | 779 | if (options.kbd_interactive_authentication) { |
780 | error("Keyboard-interactive authentication is disabled" | |
781 | " to avoid man-in-the-middle attacks."); | |
782 | options.kbd_interactive_authentication = 0; | |
783 | options.challenge_response_authentication = 0; | |
784 | } | |
785 | if (options.challenge_response_authentication) { | |
786 | error("Challenge/response authentication is disabled" | |
787 | " to avoid man-in-the-middle attacks."); | |
788 | options.challenge_response_authentication = 0; | |
789 | } | |
5260325f | 790 | if (options.forward_agent) { |
f49bc4f7 | 791 | error("Agent forwarding is disabled to avoid " |
792 | "man-in-the-middle attacks."); | |
5260325f | 793 | options.forward_agent = 0; |
794 | } | |
0b6fbf03 | 795 | if (options.forward_x11) { |
f49bc4f7 | 796 | error("X11 forwarding is disabled to avoid " |
797 | "man-in-the-middle attacks."); | |
0b6fbf03 | 798 | options.forward_x11 = 0; |
799 | } | |
f49bc4f7 | 800 | if (options.num_local_forwards > 0 || |
801 | options.num_remote_forwards > 0) { | |
802 | error("Port forwarding is disabled to avoid " | |
803 | "man-in-the-middle attacks."); | |
804 | options.num_local_forwards = | |
184eed6a | 805 | options.num_remote_forwards = 0; |
0b6fbf03 | 806 | } |
aa3378df | 807 | /* |
808 | * XXX Should permit the user to change to use the new id. | |
809 | * This could be done by converting the host key to an | |
810 | * identifying sentence, tell that the host identifies itself | |
811 | * by that sentence, and ask the user if he/she whishes to | |
812 | * accept the authentication. | |
813 | */ | |
5260325f | 814 | break; |
8a48a7ef | 815 | case HOST_FOUND: |
816 | fatal("internal error"); | |
817 | break; | |
5260325f | 818 | } |
0b6fbf03 | 819 | |
7c49df64 | 820 | if (options.check_host_ip && host_status != HOST_CHANGED && |
821 | ip_status == HOST_CHANGED) { | |
616a6b93 | 822 | snprintf(msg, sizeof(msg), |
823 | "Warning: the %s host key for '%.200s' " | |
824 | "differs from the key for the IP address '%.128s'" | |
825 | "\nOffending key for IP in %s:%d", | |
826 | type, host, ip, ip_file, ip_line); | |
827 | if (host_status == HOST_OK) { | |
828 | len = strlen(msg); | |
829 | snprintf(msg + len, sizeof(msg) - len, | |
830 | "\nMatching host key in %s:%d", | |
7203d6bb | 831 | host_file, host_line); |
616a6b93 | 832 | } |
7c49df64 | 833 | if (options.strict_host_key_checking == 1) { |
b0545fe6 | 834 | logit("%s", msg); |
f49bc4f7 | 835 | error("Exiting, you have requested strict checking."); |
836 | goto fail; | |
7c49df64 | 837 | } else if (options.strict_host_key_checking == 2) { |
616a6b93 | 838 | strlcat(msg, "\nAre you sure you want " |
839 | "to continue connecting (yes/no)? ", sizeof(msg)); | |
840 | if (!confirm(msg)) | |
f49bc4f7 | 841 | goto fail; |
616a6b93 | 842 | } else { |
b0545fe6 | 843 | logit("%s", msg); |
7c49df64 | 844 | } |
845 | } | |
846 | ||
0b6fbf03 | 847 | xfree(ip); |
f49bc4f7 | 848 | return 0; |
849 | ||
850 | fail: | |
851 | xfree(ip); | |
852 | return -1; | |
853 | } | |
854 | ||
21289cd0 | 855 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
f49bc4f7 | 856 | int |
857 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) | |
858 | { | |
859 | struct stat st; | |
0161a13d | 860 | int flags = 0; |
f49bc4f7 | 861 | |
0161a13d | 862 | if (options.verify_host_key_dns && |
863 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { | |
864 | ||
865 | if (flags & DNS_VERIFY_FOUND) { | |
866 | ||
867 | if (options.verify_host_key_dns == 1 && | |
868 | flags & DNS_VERIFY_MATCH && | |
869 | flags & DNS_VERIFY_SECURE) | |
870 | return 0; | |
871 | ||
872 | if (flags & DNS_VERIFY_MATCH) { | |
873 | matching_host_key_dns = 1; | |
874 | } else { | |
875 | warn_changed_key(host_key); | |
876 | error("Update the SSHFP RR in DNS with the new " | |
877 | "host key to get rid of this message."); | |
878 | } | |
21289cd0 | 879 | } |
880 | } | |
21289cd0 | 881 | |
f49bc4f7 | 882 | /* return ok if the key can be found in an old keyfile */ |
883 | if (stat(options.system_hostfile2, &st) == 0 || | |
884 | stat(options.user_hostfile2, &st) == 0) { | |
885 | if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, | |
886 | options.user_hostfile2, options.system_hostfile2) == 0) | |
887 | return 0; | |
888 | } | |
889 | return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, | |
890 | options.user_hostfile, options.system_hostfile); | |
95f1eccc | 891 | } |
892 | ||
8ce64345 | 893 | /* |
a306f2dd | 894 | * Starts a dialog with the server, and authenticates the current user on the |
895 | * server. This does not need any extra privileges. The basic connection | |
896 | * to the server must already have been established before this is called. | |
897 | * If login fails, this function prints an error and never returns. | |
898 | * This function does not require super-user privileges. | |
8ce64345 | 899 | */ |
900 | void | |
39c00dc2 | 901 | ssh_login(Sensitive *sensitive, const char *orighost, |
63bd8c36 | 902 | struct sockaddr *hostaddr, struct passwd *pw) |
8ce64345 | 903 | { |
a306f2dd | 904 | char *host, *cp; |
8ce64345 | 905 | char *server_user, *local_user; |
8ce64345 | 906 | |
8ce64345 | 907 | local_user = xstrdup(pw->pw_name); |
908 | server_user = options.user ? options.user : local_user; | |
909 | ||
7b2ea3a1 | 910 | /* Convert the user-supplied hostname into all lowercase. */ |
911 | host = xstrdup(orighost); | |
912 | for (cp = host; *cp; cp++) | |
913 | if (isupper(*cp)) | |
9555d258 | 914 | *cp = (char)tolower(*cp); |
7b2ea3a1 | 915 | |
916 | /* Exchange protocol version identification strings with the server. */ | |
917 | ssh_exchange_identification(); | |
918 | ||
919 | /* Put the connection into non-blocking mode. */ | |
920 | packet_set_nonblocking(); | |
921 | ||
7b2ea3a1 | 922 | /* key exchange */ |
7b2ea3a1 | 923 | /* authenticate user */ |
8ce64345 | 924 | if (compat20) { |
925 | ssh_kex2(host, hostaddr); | |
39c00dc2 | 926 | ssh_userauth2(local_user, server_user, host, sensitive); |
8ce64345 | 927 | } else { |
8ce64345 | 928 | ssh_kex(host, hostaddr); |
39c00dc2 | 929 | ssh_userauth1(local_user, server_user, host, sensitive); |
8ce64345 | 930 | } |
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 | } |