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00146caa | 1 | /* $OpenBSD: sshconnect.c,v 1.193 2006/07/22 20:48:23 stevesk 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> |
9794d008 | 21 | #include <sys/socket.h> |
22 | ||
23 | #include <netinet/in.h> | |
a75f5360 | 24 | |
b6438382 | 25 | #include <ctype.h> |
028094f4 | 26 | #include <errno.h> |
c8dfff33 | 27 | #if defined(HAVE_NETDB_H) |
28 | # include <netdb.h> | |
29 | #endif | |
b5b88c19 | 30 | #ifdef HAVE_PATHS_H |
a75f5360 | 31 | #include <paths.h> |
b5b88c19 | 32 | #endif |
b1842393 | 33 | #include <pwd.h> |
00146caa | 34 | #include <string.h> |
5188ba17 | 35 | #include <unistd.h> |
8efc0c15 | 36 | |
42f11eb2 | 37 | #include "ssh.h" |
8efc0c15 | 38 | #include "xmalloc.h" |
39 | #include "rsa.h" | |
8ce64345 | 40 | #include "buffer.h" |
8efc0c15 | 41 | #include "packet.h" |
8efc0c15 | 42 | #include "uidswap.h" |
43 | #include "compat.h" | |
4fe2af09 | 44 | #include "key.h" |
a306f2dd | 45 | #include "sshconnect.h" |
4fe2af09 | 46 | #include "hostfile.h" |
42f11eb2 | 47 | #include "log.h" |
48 | #include "readconf.h" | |
49 | #include "atomicio.h" | |
50 | #include "misc.h" | |
21289cd0 | 51 | #include "dns.h" |
28015df4 | 52 | #include "version.h" |
21289cd0 | 53 | |
a306f2dd | 54 | char *client_version_string = NULL; |
55 | char *server_version_string = NULL; | |
8ce64345 | 56 | |
ed82a2a9 | 57 | static int matching_host_key_dns = 0; |
1432b5c4 | 58 | |
3fb156df | 59 | /* import */ |
57112b5a | 60 | extern Options options; |
48e671d5 | 61 | extern char *__progname; |
3fb156df | 62 | extern uid_t original_real_uid; |
63 | extern uid_t original_effective_uid; | |
6939bbd4 | 64 | extern pid_t proxy_command_pid; |
57112b5a | 65 | |
a704dd54 | 66 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ |
67 | #define INET6_ADDRSTRLEN 46 | |
68 | #endif | |
69 | ||
8a48a7ef | 70 | static int show_other_keys(const char *, Key *); |
1a1bc5d5 | 71 | static void warn_changed_key(Key *); |
8a48a7ef | 72 | |
5260325f | 73 | /* |
74 | * Connect to the given ssh server using a proxy command. | |
75 | */ | |
396c147e | 76 | static int |
3fb156df | 77 | ssh_proxy_connect(const char *host, u_short port, const char *proxy_command) |
8efc0c15 | 78 | { |
a980cbd7 | 79 | char *command_string, *tmp; |
5260325f | 80 | int pin[2], pout[2]; |
9da5c3c9 | 81 | pid_t pid; |
48e671d5 | 82 | char strport[NI_MAXSERV]; |
5260325f | 83 | |
84 | /* Convert the port number into a string. */ | |
48e671d5 | 85 | snprintf(strport, sizeof strport, "%hu", port); |
5260325f | 86 | |
6939bbd4 | 87 | /* |
88 | * Build the final command string in the buffer by making the | |
89 | * appropriate substitutions to the given proxy command. | |
90 | * | |
aff51935 | 91 | * Use "exec" to avoid "sh -c" processes on some platforms |
6939bbd4 | 92 | * (e.g. Solaris) |
93 | */ | |
52e3daed | 94 | xasprintf(&tmp, "exec %s", proxy_command); |
a980cbd7 | 95 | command_string = percent_expand(tmp, "h", host, |
96 | "p", strport, (char *)NULL); | |
97 | xfree(tmp); | |
5260325f | 98 | |
99 | /* Create pipes for communicating with the proxy. */ | |
100 | if (pipe(pin) < 0 || pipe(pout) < 0) | |
101 | fatal("Could not create pipes to communicate with the proxy: %.100s", | |
184eed6a | 102 | strerror(errno)); |
5260325f | 103 | |
104 | debug("Executing proxy command: %.500s", command_string); | |
105 | ||
106 | /* Fork and execute the proxy command. */ | |
107 | if ((pid = fork()) == 0) { | |
108 | char *argv[10]; | |
109 | ||
110 | /* Child. Permanently give up superuser privileges. */ | |
3c33c1b6 | 111 | permanently_drop_suid(original_real_uid); |
5260325f | 112 | |
113 | /* Redirect stdin and stdout. */ | |
114 | close(pin[1]); | |
115 | if (pin[0] != 0) { | |
116 | if (dup2(pin[0], 0) < 0) | |
117 | perror("dup2 stdin"); | |
118 | close(pin[0]); | |
119 | } | |
120 | close(pout[0]); | |
121 | if (dup2(pout[1], 1) < 0) | |
122 | perror("dup2 stdout"); | |
123 | /* Cannot be 1 because pin allocated two descriptors. */ | |
124 | close(pout[1]); | |
125 | ||
126 | /* Stderr is left as it is so that error messages get | |
127 | printed on the user's terminal. */ | |
30228d7c | 128 | argv[0] = _PATH_BSHELL; |
5260325f | 129 | argv[1] = "-c"; |
130 | argv[2] = command_string; | |
131 | argv[3] = NULL; | |
132 | ||
133 | /* Execute the proxy command. Note that we gave up any | |
134 | extra privileges above. */ | |
328654d8 | 135 | execv(argv[0], argv); |
136 | perror(argv[0]); | |
5260325f | 137 | exit(1); |
8efc0c15 | 138 | } |
5260325f | 139 | /* Parent. */ |
140 | if (pid < 0) | |
141 | fatal("fork failed: %.100s", strerror(errno)); | |
6939bbd4 | 142 | else |
143 | proxy_command_pid = pid; /* save pid to clean up later */ | |
5260325f | 144 | |
145 | /* Close child side of the descriptors. */ | |
146 | close(pin[0]); | |
147 | close(pout[1]); | |
148 | ||
149 | /* Free the command name. */ | |
a980cbd7 | 150 | xfree(command_string); |
5260325f | 151 | |
152 | /* Set the connection file descriptors. */ | |
153 | packet_set_connection(pout[0], pin[1]); | |
8efc0c15 | 154 | |
ce773142 | 155 | /* Indicate OK return */ |
156 | return 0; | |
5260325f | 157 | } |
8efc0c15 | 158 | |
5260325f | 159 | /* |
160 | * Creates a (possibly privileged) socket for use as the ssh connection. | |
161 | */ | |
396c147e | 162 | static int |
3e131a6d | 163 | ssh_create_socket(int privileged, struct addrinfo *ai) |
8efc0c15 | 164 | { |
3435f5a6 | 165 | int sock, gaierr; |
166 | struct addrinfo hints, *res; | |
5260325f | 167 | |
aa3378df | 168 | /* |
169 | * If we are running as root and want to connect to a privileged | |
170 | * port, bind our own socket to a privileged port. | |
171 | */ | |
5260325f | 172 | if (privileged) { |
173 | int p = IPPORT_RESERVED - 1; | |
3fb156df | 174 | PRIV_START; |
3e131a6d | 175 | sock = rresvport_af(&p, ai->ai_family); |
3fb156df | 176 | PRIV_END; |
5260325f | 177 | if (sock < 0) |
3e131a6d | 178 | error("rresvport: af=%d %.100s", ai->ai_family, |
179 | strerror(errno)); | |
c8d54615 | 180 | else |
181 | debug("Allocated local port %d.", p); | |
3435f5a6 | 182 | return sock; |
183 | } | |
3e131a6d | 184 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3435f5a6 | 185 | if (sock < 0) |
186 | error("socket: %.100s", strerror(errno)); | |
3435f5a6 | 187 | |
188 | /* Bind the socket to an alternative local IP address */ | |
189 | if (options.bind_address == NULL) | |
190 | return sock; | |
191 | ||
192 | memset(&hints, 0, sizeof(hints)); | |
3e131a6d | 193 | hints.ai_family = ai->ai_family; |
194 | hints.ai_socktype = ai->ai_socktype; | |
195 | hints.ai_protocol = ai->ai_protocol; | |
3435f5a6 | 196 | hints.ai_flags = AI_PASSIVE; |
197 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); | |
198 | if (gaierr) { | |
199 | error("getaddrinfo: %s: %s", options.bind_address, | |
200 | gai_strerror(gaierr)); | |
201 | close(sock); | |
202 | return -1; | |
203 | } | |
204 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { | |
205 | error("bind: %s: %s", options.bind_address, strerror(errno)); | |
206 | close(sock); | |
207 | freeaddrinfo(res); | |
208 | return -1; | |
5260325f | 209 | } |
3435f5a6 | 210 | freeaddrinfo(res); |
5260325f | 211 | return sock; |
8efc0c15 | 212 | } |
213 | ||
09ab3296 | 214 | static int |
215 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, | |
216 | socklen_t addrlen, int timeout) | |
217 | { | |
218 | fd_set *fdset; | |
219 | struct timeval tv; | |
220 | socklen_t optlen; | |
52e3daed | 221 | int optval, rc, result = -1; |
09ab3296 | 222 | |
223 | if (timeout <= 0) | |
224 | return (connect(sockfd, serv_addr, addrlen)); | |
225 | ||
2daf1db1 | 226 | set_nonblock(sockfd); |
09ab3296 | 227 | rc = connect(sockfd, serv_addr, addrlen); |
2daf1db1 | 228 | if (rc == 0) { |
229 | unset_nonblock(sockfd); | |
09ab3296 | 230 | return (0); |
2daf1db1 | 231 | } |
09ab3296 | 232 | if (errno != EINPROGRESS) |
233 | return (-1); | |
234 | ||
52e3daed | 235 | fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS), |
236 | sizeof(fd_mask)); | |
09ab3296 | 237 | FD_SET(sockfd, fdset); |
238 | tv.tv_sec = timeout; | |
239 | tv.tv_usec = 0; | |
240 | ||
f8cc7664 | 241 | for (;;) { |
09ab3296 | 242 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
243 | if (rc != -1 || errno != EINTR) | |
244 | break; | |
245 | } | |
246 | ||
f8cc7664 | 247 | switch (rc) { |
09ab3296 | 248 | case 0: |
249 | /* Timed out */ | |
250 | errno = ETIMEDOUT; | |
da54f5be | 251 | break; |
09ab3296 | 252 | case -1: |
253 | /* Select error */ | |
aff51935 | 254 | debug("select: %s", strerror(errno)); |
da54f5be | 255 | break; |
09ab3296 | 256 | case 1: |
257 | /* Completed or failed */ | |
258 | optval = 0; | |
259 | optlen = sizeof(optval); | |
aff51935 | 260 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
ce26c02a | 261 | &optlen) == -1) { |
aff51935 | 262 | debug("getsockopt: %s", strerror(errno)); |
da54f5be | 263 | break; |
ce26c02a | 264 | } |
09ab3296 | 265 | if (optval != 0) { |
266 | errno = optval; | |
da54f5be | 267 | break; |
09ab3296 | 268 | } |
da54f5be | 269 | result = 0; |
2daf1db1 | 270 | unset_nonblock(sockfd); |
09ab3296 | 271 | break; |
272 | default: | |
273 | /* Should not occur */ | |
274 | fatal("Bogus return (%d) from select()", rc); | |
275 | } | |
276 | ||
da54f5be | 277 | xfree(fdset); |
278 | return (result); | |
09ab3296 | 279 | } |
280 | ||
5260325f | 281 | /* |
48e671d5 | 282 | * Opens a TCP/IP connection to the remote server on the given host. |
283 | * The address of the remote host will be returned in hostaddr. | |
3fb156df | 284 | * If port is 0, the default port will be used. If needpriv is true, |
5260325f | 285 | * a privileged port will be allocated to make the connection. |
3fb156df | 286 | * This requires super-user privileges if needpriv is true. |
5260325f | 287 | * Connection_attempts specifies the maximum number of tries (one per |
288 | * second). If proxy_command is non-NULL, it specifies the command (with %h | |
289 | * and %p substituted for host and port, respectively) to use to contact | |
290 | * the daemon. | |
291 | */ | |
292 | int | |
48e671d5 | 293 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
dab89049 | 294 | u_short port, int family, int connection_attempts, |
3fb156df | 295 | int needpriv, const char *proxy_command) |
8efc0c15 | 296 | { |
b5c334cc | 297 | int gaierr; |
298 | int on = 1; | |
48e671d5 | 299 | int sock = -1, attempt; |
48e671d5 | 300 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
b5c334cc | 301 | struct addrinfo hints, *ai, *aitop; |
5260325f | 302 | |
a77673cc | 303 | debug2("ssh_connect: needpriv %d", needpriv); |
5260325f | 304 | |
5260325f | 305 | /* If a proxy command is given, connect using it. */ |
306 | if (proxy_command != NULL) | |
3fb156df | 307 | return ssh_proxy_connect(host, port, proxy_command); |
5260325f | 308 | |
309 | /* No proxy command. */ | |
310 | ||
48e671d5 | 311 | memset(&hints, 0, sizeof(hints)); |
dab89049 | 312 | hints.ai_family = family; |
48e671d5 | 313 | hints.ai_socktype = SOCK_STREAM; |
d6133f43 | 314 | snprintf(strport, sizeof strport, "%u", port); |
48e671d5 | 315 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
316 | fatal("%s: %.100s: %s", __progname, host, | |
317 | gai_strerror(gaierr)); | |
5260325f | 318 | |
4439dde1 | 319 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
5260325f | 320 | if (attempt > 0) |
321 | debug("Trying again..."); | |
322 | ||
4439dde1 | 323 | /* |
324 | * Loop through addresses for this host, and try each one in | |
325 | * sequence until the connection succeeds. | |
326 | */ | |
48e671d5 | 327 | for (ai = aitop; ai; ai = ai->ai_next) { |
328 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
329 | continue; | |
330 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
331 | ntop, sizeof(ntop), strport, sizeof(strport), | |
332 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
333 | error("ssh_connect: getnameinfo failed"); | |
334 | continue; | |
335 | } | |
336 | debug("Connecting to %.200s [%.100s] port %s.", | |
337 | host, ntop, strport); | |
338 | ||
339 | /* Create a socket for connecting. */ | |
3e131a6d | 340 | sock = ssh_create_socket(needpriv, ai); |
48e671d5 | 341 | if (sock < 0) |
ce773142 | 342 | /* Any error is already output */ |
48e671d5 | 343 | continue; |
344 | ||
09ab3296 | 345 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
346 | options.connection_timeout) >= 0) { | |
48e671d5 | 347 | /* Successful connection. */ |
cd332296 | 348 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
5260325f | 349 | break; |
48e671d5 | 350 | } else { |
c750d869 | 351 | debug("connect to address %s port %s: %s", |
352 | ntop, strport, strerror(errno)); | |
5260325f | 353 | close(sock); |
4439dde1 | 354 | sock = -1; |
5260325f | 355 | } |
8efc0c15 | 356 | } |
4439dde1 | 357 | if (sock != -1) |
48e671d5 | 358 | break; /* Successful connection. */ |
8efc0c15 | 359 | |
5260325f | 360 | /* Sleep a moment before retrying. */ |
361 | sleep(1); | |
362 | } | |
48e671d5 | 363 | |
364 | freeaddrinfo(aitop); | |
365 | ||
5260325f | 366 | /* Return failure if we didn't get a successful connection. */ |
4439dde1 | 367 | if (sock == -1) { |
cf039bd1 | 368 | error("ssh: connect to host %s port %s: %s", |
9bd68577 | 369 | host, strport, strerror(errno)); |
cf039bd1 | 370 | return (-1); |
9bd68577 | 371 | } |
8efc0c15 | 372 | |
5260325f | 373 | debug("Connection established."); |
8efc0c15 | 374 | |
fd573618 | 375 | /* Set SO_KEEPALIVE if requested. */ |
376 | if (options.tcp_keep_alive && | |
b5c334cc | 377 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
378 | sizeof(on)) < 0) | |
379 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
8efc0c15 | 380 | |
5260325f | 381 | /* Set the connection. */ |
382 | packet_set_connection(sock, sock); | |
8efc0c15 | 383 | |
ce773142 | 384 | return 0; |
8efc0c15 | 385 | } |
386 | ||
5260325f | 387 | /* |
388 | * Waits for the server identification string, and sends our own | |
389 | * identification string. | |
390 | */ | |
396c147e | 391 | static void |
5ca51e19 | 392 | ssh_exchange_identification(void) |
8efc0c15 | 393 | { |
5260325f | 394 | char buf[256], remote_version[256]; /* must be same size! */ |
2ceb8101 | 395 | int remote_major, remote_minor, mismatch; |
5260325f | 396 | int connection_in = packet_get_connection_in(); |
397 | int connection_out = packet_get_connection_out(); | |
2b87da3b | 398 | int minor1 = PROTOCOL_MINOR_1; |
e5c76324 | 399 | u_int i, n; |
5260325f | 400 | |
05624c18 | 401 | /* Read other side's version identification. */ |
e5c76324 | 402 | for (n = 0;;) { |
38c295d6 | 403 | for (i = 0; i < sizeof(buf) - 1; i++) { |
05624c18 | 404 | size_t len = atomicio(read, connection_in, &buf[i], 1); |
405 | ||
56964485 | 406 | if (len != 1 && errno == EPIPE) |
38c295d6 | 407 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
05624c18 | 408 | else if (len != 1) |
409 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); | |
38c295d6 | 410 | if (buf[i] == '\r') { |
411 | buf[i] = '\n'; | |
412 | buf[i + 1] = 0; | |
413 | continue; /**XXX wait for \n */ | |
414 | } | |
415 | if (buf[i] == '\n') { | |
416 | buf[i + 1] = 0; | |
417 | break; | |
418 | } | |
e5c76324 | 419 | if (++n > 65536) |
420 | fatal("ssh_exchange_identification: No banner received"); | |
5260325f | 421 | } |
38c295d6 | 422 | buf[sizeof(buf) - 1] = 0; |
423 | if (strncmp(buf, "SSH-", 4) == 0) | |
5260325f | 424 | break; |
38c295d6 | 425 | debug("ssh_exchange_identification: %s", buf); |
8efc0c15 | 426 | } |
8ce64345 | 427 | server_version_string = xstrdup(buf); |
5260325f | 428 | |
aa3378df | 429 | /* |
430 | * Check that the versions match. In future this might accept | |
431 | * several versions and set appropriate flags to handle them. | |
432 | */ | |
8ce64345 | 433 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
434 | &remote_major, &remote_minor, remote_version) != 3) | |
5260325f | 435 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
436 | debug("Remote protocol version %d.%d, remote software version %.100s", | |
184eed6a | 437 | remote_major, remote_minor, remote_version); |
5260325f | 438 | |
8ce64345 | 439 | compat_datafellows(remote_version); |
a8be9f80 | 440 | mismatch = 0; |
441 | ||
6aacefa7 | 442 | switch (remote_major) { |
a8be9f80 | 443 | case 1: |
444 | if (remote_minor == 99 && | |
445 | (options.protocol & SSH_PROTO_2) && | |
446 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { | |
447 | enable_compat20(); | |
448 | break; | |
5260325f | 449 | } |
a8be9f80 | 450 | if (!(options.protocol & SSH_PROTO_1)) { |
451 | mismatch = 1; | |
452 | break; | |
453 | } | |
454 | if (remote_minor < 3) { | |
455 | fatal("Remote machine has too old SSH software version."); | |
fa08c86b | 456 | } else if (remote_minor == 3 || remote_minor == 4) { |
a8be9f80 | 457 | /* We speak 1.3, too. */ |
458 | enable_compat13(); | |
fa08c86b | 459 | minor1 = 3; |
a8be9f80 | 460 | if (options.forward_agent) { |
bbe88b6d | 461 | logit("Agent forwarding disabled for protocol 1.3"); |
a8be9f80 | 462 | options.forward_agent = 0; |
463 | } | |
464 | } | |
465 | break; | |
466 | case 2: | |
467 | if (options.protocol & SSH_PROTO_2) { | |
468 | enable_compat20(); | |
469 | break; | |
470 | } | |
471 | /* FALLTHROUGH */ | |
6ae2364d | 472 | default: |
a8be9f80 | 473 | mismatch = 1; |
474 | break; | |
8efc0c15 | 475 | } |
a8be9f80 | 476 | if (mismatch) |
5260325f | 477 | fatal("Protocol major versions differ: %d vs. %d", |
a8be9f80 | 478 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
479 | remote_major); | |
5260325f | 480 | /* Send our own protocol version identification. */ |
481 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | |
a8be9f80 | 482 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
fa08c86b | 483 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
8ce64345 | 484 | SSH_VERSION); |
dc54438a | 485 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
5260325f | 486 | fatal("write: %.100s", strerror(errno)); |
8ce64345 | 487 | client_version_string = xstrdup(buf); |
488 | chop(client_version_string); | |
489 | chop(server_version_string); | |
490 | debug("Local version string %.100s", client_version_string); | |
8efc0c15 | 491 | } |
492 | ||
f21032a6 | 493 | /* defaults to 'no' */ |
396c147e | 494 | static int |
a2c92c4a | 495 | confirm(const char *prompt) |
8efc0c15 | 496 | { |
616a6b93 | 497 | const char *msg, *again = "Please type 'yes' or 'no': "; |
498 | char *p; | |
499 | int ret = -1; | |
5260325f | 500 | |
f21032a6 | 501 | if (options.batch_mode) |
502 | return 0; | |
616a6b93 | 503 | for (msg = prompt;;msg = again) { |
504 | p = read_passphrase(msg, RP_ECHO); | |
505 | if (p == NULL || | |
506 | (p[0] == '\0') || (p[0] == '\n') || | |
507 | strncasecmp(p, "no", 2) == 0) | |
508 | ret = 0; | |
f11fe301 | 509 | if (p && strncasecmp(p, "yes", 3) == 0) |
616a6b93 | 510 | ret = 1; |
511 | if (p) | |
512 | xfree(p); | |
513 | if (ret != -1) | |
514 | return ret; | |
8efc0c15 | 515 | } |
8efc0c15 | 516 | } |
517 | ||
5260325f | 518 | /* |
f49bc4f7 | 519 | * check whether the supplied host key is valid, return -1 if the key |
520 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. | |
5260325f | 521 | */ |
396c147e | 522 | static int |
d4530052 | 523 | check_host_key(char *hostname, struct sockaddr *hostaddr, Key *host_key, |
f49bc4f7 | 524 | int readonly, const char *user_hostfile, const char *system_hostfile) |
8efc0c15 | 525 | { |
4fe2af09 | 526 | Key *file_key; |
b6c7b7b7 | 527 | const char *type = key_type(host_key); |
d4530052 | 528 | char *ip = NULL, *host = NULL; |
22138a36 | 529 | char hostline[1000], *hostp, *fp; |
5260325f | 530 | HostStatus host_status; |
531 | HostStatus ip_status; | |
e79276c2 | 532 | int r, local = 0, host_ip_differ = 0; |
20af321f | 533 | int salen; |
48e671d5 | 534 | char ntop[NI_MAXHOST]; |
616a6b93 | 535 | char msg[1024]; |
1432b5c4 | 536 | int len, host_line, ip_line; |
1e3b8b07 | 537 | const char *host_file = NULL, *ip_file = NULL; |
48e671d5 | 538 | |
539 | /* | |
540 | * Force accepting of the host key for loopback/localhost. The | |
541 | * problem is that if the home directory is NFS-mounted to multiple | |
542 | * machines, localhost will refer to a different machine in each of | |
543 | * them, and the user will get bogus HOST_CHANGED warnings. This | |
544 | * essentially disables host authentication for localhost; however, | |
545 | * this is probably not a real problem. | |
546 | */ | |
a306f2dd | 547 | /** hostaddr == 0! */ |
48e671d5 | 548 | switch (hostaddr->sa_family) { |
549 | case AF_INET: | |
f49bc4f7 | 550 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
4e2e5cfd | 551 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
20af321f | 552 | salen = sizeof(struct sockaddr_in); |
48e671d5 | 553 | break; |
554 | case AF_INET6: | |
f49bc4f7 | 555 | local = IN6_IS_ADDR_LOOPBACK( |
556 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | |
20af321f | 557 | salen = sizeof(struct sockaddr_in6); |
48e671d5 | 558 | break; |
559 | default: | |
560 | local = 0; | |
20af321f | 561 | salen = sizeof(struct sockaddr_storage); |
48e671d5 | 562 | break; |
563 | } | |
8bbc048a | 564 | if (options.no_host_authentication_for_localhost == 1 && local && |
565 | options.host_key_alias == NULL) { | |
7c49df64 | 566 | debug("Forcing accepting of host key for " |
567 | "loopback/localhost."); | |
f49bc4f7 | 568 | return 0; |
48e671d5 | 569 | } |
5260325f | 570 | |
57112b5a | 571 | /* |
7c49df64 | 572 | * We don't have the remote ip-address for connections |
573 | * using a proxy command | |
574 | */ | |
575 | if (options.proxy_command == NULL) { | |
576 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), | |
577 | NULL, 0, NI_NUMERICHOST) != 0) | |
578 | fatal("check_host_key: getnameinfo failed"); | |
d4530052 | 579 | ip = put_host_port(ntop, options.port); |
7c49df64 | 580 | } else { |
581 | ip = xstrdup("<no hostip for proxy command>"); | |
582 | } | |
583 | /* | |
584 | * Turn off check_host_ip if the connection is to localhost, via proxy | |
585 | * command or if we don't have a hostname to compare with | |
57112b5a | 586 | */ |
d4530052 | 587 | if (options.check_host_ip && (local || |
588 | strcmp(hostname, ip) == 0 || options.proxy_command != NULL)) | |
57112b5a | 589 | options.check_host_ip = 0; |
590 | ||
8abcdba4 | 591 | /* |
d4530052 | 592 | * Allow the user to record the key under a different name or |
593 | * differentiate a non-standard port. This is useful for ssh | |
594 | * tunneling over forwarded connections or if you run multiple | |
595 | * sshd's on different ports on the same machine. | |
8abcdba4 | 596 | */ |
597 | if (options.host_key_alias != NULL) { | |
d4530052 | 598 | host = xstrdup(options.host_key_alias); |
8abcdba4 | 599 | debug("using hostkeyalias: %s", host); |
d4530052 | 600 | } else { |
601 | host = put_host_port(hostname, options.port); | |
8abcdba4 | 602 | } |
603 | ||
95f1eccc | 604 | /* |
605 | * Store the host key from the known host file in here so that we can | |
606 | * compare it with the key for the IP address. | |
607 | */ | |
4fe2af09 | 608 | file_key = key_new(host_key->type); |
5260325f | 609 | |
aa3378df | 610 | /* |
7b9b0103 | 611 | * Check if the host key is present in the user's list of known |
aa3378df | 612 | * hosts or in the systemwide list. |
613 | */ | |
1e3b8b07 | 614 | host_file = user_hostfile; |
f49bc4f7 | 615 | host_status = check_host_in_hostfile(host_file, host, host_key, |
184eed6a | 616 | file_key, &host_line); |
1e3b8b07 | 617 | if (host_status == HOST_NEW) { |
618 | host_file = system_hostfile; | |
f49bc4f7 | 619 | host_status = check_host_in_hostfile(host_file, host, host_key, |
620 | file_key, &host_line); | |
1e3b8b07 | 621 | } |
aa3378df | 622 | /* |
623 | * Also perform check for the ip address, skip the check if we are | |
624 | * localhost or the hostname was an ip address to begin with | |
625 | */ | |
7c49df64 | 626 | if (options.check_host_ip) { |
4fe2af09 | 627 | Key *ip_key = key_new(host_key->type); |
5260325f | 628 | |
1e3b8b07 | 629 | ip_file = user_hostfile; |
f49bc4f7 | 630 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
631 | ip_key, &ip_line); | |
1e3b8b07 | 632 | if (ip_status == HOST_NEW) { |
633 | ip_file = system_hostfile; | |
f49bc4f7 | 634 | ip_status = check_host_in_hostfile(ip_file, ip, |
635 | host_key, ip_key, &ip_line); | |
1e3b8b07 | 636 | } |
5260325f | 637 | if (host_status == HOST_CHANGED && |
4fe2af09 | 638 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
5260325f | 639 | host_ip_differ = 1; |
640 | ||
4fe2af09 | 641 | key_free(ip_key); |
5260325f | 642 | } else |
643 | ip_status = host_status; | |
644 | ||
4fe2af09 | 645 | key_free(file_key); |
5260325f | 646 | |
647 | switch (host_status) { | |
648 | case HOST_OK: | |
649 | /* The host is known and the key matches. */ | |
1d1ffb87 | 650 | debug("Host '%.200s' is known and matches the %s host key.", |
651 | host, type); | |
1e3b8b07 | 652 | debug("Found key in %s:%d", host_file, host_line); |
7c49df64 | 653 | if (options.check_host_ip && ip_status == HOST_NEW) { |
f49bc4f7 | 654 | if (readonly) |
bbe88b6d | 655 | logit("%s host key for IP address " |
f49bc4f7 | 656 | "'%.128s' not in list of known hosts.", |
7c49df64 | 657 | type, ip); |
f49bc4f7 | 658 | else if (!add_host_to_hostfile(user_hostfile, ip, |
5c63c2ab | 659 | host_key, options.hash_known_hosts)) |
bbe88b6d | 660 | logit("Failed to add the %s host key for IP " |
f49bc4f7 | 661 | "address '%.128s' to the list of known " |
662 | "hosts (%.30s).", type, ip, user_hostfile); | |
663 | else | |
bbe88b6d | 664 | logit("Warning: Permanently added the %s host " |
f49bc4f7 | 665 | "key for IP address '%.128s' to the list " |
666 | "of known hosts.", type, ip); | |
5260325f | 667 | } |
668 | break; | |
669 | case HOST_NEW: | |
f49bc4f7 | 670 | if (readonly) |
671 | goto fail; | |
5260325f | 672 | /* The host is new. */ |
673 | if (options.strict_host_key_checking == 1) { | |
f49bc4f7 | 674 | /* |
675 | * User has requested strict host key checking. We | |
676 | * will not add the host key automatically. The only | |
677 | * alternative left is to abort. | |
678 | */ | |
679 | error("No %s host key is known for %.200s and you " | |
680 | "have requested strict checking.", type, host); | |
681 | goto fail; | |
5260325f | 682 | } else if (options.strict_host_key_checking == 2) { |
1432b5c4 | 683 | char msg1[1024], msg2[1024]; |
684 | ||
685 | if (show_other_keys(host, host_key)) | |
686 | snprintf(msg1, sizeof(msg1), | |
4e2e5cfd | 687 | "\nbut keys of different type are already" |
688 | " known for this host."); | |
1432b5c4 | 689 | else |
690 | snprintf(msg1, sizeof(msg1), "."); | |
5260325f | 691 | /* The default */ |
22138a36 | 692 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
1432b5c4 | 693 | msg2[0] = '\0'; |
1432b5c4 | 694 | if (options.verify_host_key_dns) { |
0161a13d | 695 | if (matching_host_key_dns) |
1432b5c4 | 696 | snprintf(msg2, sizeof(msg2), |
697 | "Matching host key fingerprint" | |
698 | " found in DNS.\n"); | |
699 | else | |
700 | snprintf(msg2, sizeof(msg2), | |
701 | "No matching host key fingerprint" | |
702 | " found in DNS.\n"); | |
703 | } | |
616a6b93 | 704 | snprintf(msg, sizeof(msg), |
f49bc4f7 | 705 | "The authenticity of host '%.200s (%s)' can't be " |
8a48a7ef | 706 | "established%s\n" |
1432b5c4 | 707 | "%s key fingerprint is %s.\n%s" |
f49bc4f7 | 708 | "Are you sure you want to continue connecting " |
8a48a7ef | 709 | "(yes/no)? ", |
1432b5c4 | 710 | host, ip, msg1, type, fp, msg2); |
22138a36 | 711 | xfree(fp); |
616a6b93 | 712 | if (!confirm(msg)) |
f49bc4f7 | 713 | goto fail; |
5260325f | 714 | } |
f49bc4f7 | 715 | /* |
716 | * If not in strict mode, add the key automatically to the | |
717 | * local known_hosts file. | |
718 | */ | |
e79276c2 | 719 | if (options.check_host_ip && ip_status == HOST_NEW) { |
720 | snprintf(hostline, sizeof(hostline), "%s,%s", | |
721 | host, ip); | |
722 | hostp = hostline; | |
723 | if (options.hash_known_hosts) { | |
724 | /* Add hash of host and IP separately */ | |
725 | r = add_host_to_hostfile(user_hostfile, host, | |
726 | host_key, options.hash_known_hosts) && | |
727 | add_host_to_hostfile(user_hostfile, ip, | |
728 | host_key, options.hash_known_hosts); | |
729 | } else { | |
730 | /* Add unhashed "host,ip" */ | |
731 | r = add_host_to_hostfile(user_hostfile, | |
732 | hostline, host_key, | |
733 | options.hash_known_hosts); | |
734 | } | |
735 | } else { | |
736 | r = add_host_to_hostfile(user_hostfile, host, host_key, | |
737 | options.hash_known_hosts); | |
738 | hostp = host; | |
739 | } | |
740 | ||
741 | if (!r) | |
bbe88b6d | 742 | logit("Failed to add the host to the list of known " |
f49bc4f7 | 743 | "hosts (%.500s).", user_hostfile); |
5260325f | 744 | else |
bbe88b6d | 745 | logit("Warning: Permanently added '%.200s' (%s) to the " |
f49bc4f7 | 746 | "list of known hosts.", hostp, type); |
5260325f | 747 | break; |
748 | case HOST_CHANGED: | |
749 | if (options.check_host_ip && host_ip_differ) { | |
ca75d7de | 750 | char *key_msg; |
5260325f | 751 | if (ip_status == HOST_NEW) |
ca75d7de | 752 | key_msg = "is unknown"; |
5260325f | 753 | else if (ip_status == HOST_OK) |
ca75d7de | 754 | key_msg = "is unchanged"; |
5260325f | 755 | else |
ca75d7de | 756 | key_msg = "has a different value"; |
5260325f | 757 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
758 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); | |
759 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1d1ffb87 | 760 | error("The %s host key for %s has changed,", type, host); |
5260325f | 761 | error("and the key for the according IP address %s", ip); |
ca75d7de | 762 | error("%s. This could either mean that", key_msg); |
5260325f | 763 | error("DNS SPOOFING is happening or the IP address for the host"); |
1e3b8b07 | 764 | error("and its host key have changed at the same time."); |
7c49df64 | 765 | if (ip_status != HOST_NEW) |
1e3b8b07 | 766 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
5260325f | 767 | } |
768 | /* The host key has changed. */ | |
1a1bc5d5 | 769 | warn_changed_key(host_key); |
5260325f | 770 | error("Add correct host key in %.100s to get rid of this message.", |
8abcdba4 | 771 | user_hostfile); |
1e3b8b07 | 772 | error("Offending key in %s:%d", host_file, host_line); |
5260325f | 773 | |
aa3378df | 774 | /* |
775 | * If strict host key checking is in use, the user will have | |
776 | * to edit the key manually and we can only abort. | |
777 | */ | |
f49bc4f7 | 778 | if (options.strict_host_key_checking) { |
779 | error("%s host key for %.200s has changed and you have " | |
780 | "requested strict checking.", type, host); | |
781 | goto fail; | |
782 | } | |
5260325f | 783 | |
aa3378df | 784 | /* |
785 | * If strict host key checking has not been requested, allow | |
d453a600 | 786 | * the connection but without MITM-able authentication or |
aa3378df | 787 | * agent forwarding. |
788 | */ | |
5260325f | 789 | if (options.password_authentication) { |
f49bc4f7 | 790 | error("Password authentication is disabled to avoid " |
791 | "man-in-the-middle attacks."); | |
5260325f | 792 | options.password_authentication = 0; |
793 | } | |
d453a600 | 794 | if (options.kbd_interactive_authentication) { |
795 | error("Keyboard-interactive authentication is disabled" | |
796 | " to avoid man-in-the-middle attacks."); | |
797 | options.kbd_interactive_authentication = 0; | |
798 | options.challenge_response_authentication = 0; | |
799 | } | |
800 | if (options.challenge_response_authentication) { | |
801 | error("Challenge/response authentication is disabled" | |
802 | " to avoid man-in-the-middle attacks."); | |
803 | options.challenge_response_authentication = 0; | |
804 | } | |
5260325f | 805 | if (options.forward_agent) { |
f49bc4f7 | 806 | error("Agent forwarding is disabled to avoid " |
807 | "man-in-the-middle attacks."); | |
5260325f | 808 | options.forward_agent = 0; |
809 | } | |
0b6fbf03 | 810 | if (options.forward_x11) { |
f49bc4f7 | 811 | error("X11 forwarding is disabled to avoid " |
812 | "man-in-the-middle attacks."); | |
0b6fbf03 | 813 | options.forward_x11 = 0; |
814 | } | |
f49bc4f7 | 815 | if (options.num_local_forwards > 0 || |
816 | options.num_remote_forwards > 0) { | |
817 | error("Port forwarding is disabled to avoid " | |
818 | "man-in-the-middle attacks."); | |
819 | options.num_local_forwards = | |
184eed6a | 820 | options.num_remote_forwards = 0; |
0b6fbf03 | 821 | } |
aa3378df | 822 | /* |
823 | * XXX Should permit the user to change to use the new id. | |
824 | * This could be done by converting the host key to an | |
825 | * identifying sentence, tell that the host identifies itself | |
826 | * by that sentence, and ask the user if he/she whishes to | |
827 | * accept the authentication. | |
828 | */ | |
5260325f | 829 | break; |
8a48a7ef | 830 | case HOST_FOUND: |
831 | fatal("internal error"); | |
832 | break; | |
5260325f | 833 | } |
0b6fbf03 | 834 | |
7c49df64 | 835 | if (options.check_host_ip && host_status != HOST_CHANGED && |
836 | ip_status == HOST_CHANGED) { | |
616a6b93 | 837 | snprintf(msg, sizeof(msg), |
838 | "Warning: the %s host key for '%.200s' " | |
839 | "differs from the key for the IP address '%.128s'" | |
840 | "\nOffending key for IP in %s:%d", | |
841 | type, host, ip, ip_file, ip_line); | |
842 | if (host_status == HOST_OK) { | |
843 | len = strlen(msg); | |
844 | snprintf(msg + len, sizeof(msg) - len, | |
845 | "\nMatching host key in %s:%d", | |
7203d6bb | 846 | host_file, host_line); |
616a6b93 | 847 | } |
7c49df64 | 848 | if (options.strict_host_key_checking == 1) { |
b0545fe6 | 849 | logit("%s", msg); |
f49bc4f7 | 850 | error("Exiting, you have requested strict checking."); |
851 | goto fail; | |
7c49df64 | 852 | } else if (options.strict_host_key_checking == 2) { |
616a6b93 | 853 | strlcat(msg, "\nAre you sure you want " |
854 | "to continue connecting (yes/no)? ", sizeof(msg)); | |
855 | if (!confirm(msg)) | |
f49bc4f7 | 856 | goto fail; |
616a6b93 | 857 | } else { |
b0545fe6 | 858 | logit("%s", msg); |
7c49df64 | 859 | } |
860 | } | |
861 | ||
0b6fbf03 | 862 | xfree(ip); |
d4530052 | 863 | xfree(host); |
f49bc4f7 | 864 | return 0; |
865 | ||
866 | fail: | |
867 | xfree(ip); | |
d4530052 | 868 | xfree(host); |
f49bc4f7 | 869 | return -1; |
870 | } | |
871 | ||
21289cd0 | 872 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
f49bc4f7 | 873 | int |
874 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) | |
875 | { | |
876 | struct stat st; | |
0161a13d | 877 | int flags = 0; |
f49bc4f7 | 878 | |
0161a13d | 879 | if (options.verify_host_key_dns && |
880 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { | |
881 | ||
882 | if (flags & DNS_VERIFY_FOUND) { | |
883 | ||
884 | if (options.verify_host_key_dns == 1 && | |
885 | flags & DNS_VERIFY_MATCH && | |
886 | flags & DNS_VERIFY_SECURE) | |
887 | return 0; | |
888 | ||
889 | if (flags & DNS_VERIFY_MATCH) { | |
890 | matching_host_key_dns = 1; | |
891 | } else { | |
892 | warn_changed_key(host_key); | |
893 | error("Update the SSHFP RR in DNS with the new " | |
894 | "host key to get rid of this message."); | |
895 | } | |
21289cd0 | 896 | } |
897 | } | |
21289cd0 | 898 | |
f49bc4f7 | 899 | /* return ok if the key can be found in an old keyfile */ |
900 | if (stat(options.system_hostfile2, &st) == 0 || | |
901 | stat(options.user_hostfile2, &st) == 0) { | |
902 | if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, | |
903 | options.user_hostfile2, options.system_hostfile2) == 0) | |
904 | return 0; | |
905 | } | |
906 | return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, | |
907 | options.user_hostfile, options.system_hostfile); | |
95f1eccc | 908 | } |
909 | ||
8ce64345 | 910 | /* |
a306f2dd | 911 | * Starts a dialog with the server, and authenticates the current user on the |
912 | * server. This does not need any extra privileges. The basic connection | |
913 | * to the server must already have been established before this is called. | |
914 | * If login fails, this function prints an error and never returns. | |
915 | * This function does not require super-user privileges. | |
8ce64345 | 916 | */ |
917 | void | |
39c00dc2 | 918 | ssh_login(Sensitive *sensitive, const char *orighost, |
63bd8c36 | 919 | struct sockaddr *hostaddr, struct passwd *pw) |
8ce64345 | 920 | { |
a306f2dd | 921 | char *host, *cp; |
8ce64345 | 922 | char *server_user, *local_user; |
8ce64345 | 923 | |
8ce64345 | 924 | local_user = xstrdup(pw->pw_name); |
925 | server_user = options.user ? options.user : local_user; | |
926 | ||
7b2ea3a1 | 927 | /* Convert the user-supplied hostname into all lowercase. */ |
928 | host = xstrdup(orighost); | |
929 | for (cp = host; *cp; cp++) | |
930 | if (isupper(*cp)) | |
9555d258 | 931 | *cp = (char)tolower(*cp); |
7b2ea3a1 | 932 | |
933 | /* Exchange protocol version identification strings with the server. */ | |
934 | ssh_exchange_identification(); | |
935 | ||
936 | /* Put the connection into non-blocking mode. */ | |
937 | packet_set_nonblocking(); | |
938 | ||
7b2ea3a1 | 939 | /* key exchange */ |
7b2ea3a1 | 940 | /* authenticate user */ |
8ce64345 | 941 | if (compat20) { |
942 | ssh_kex2(host, hostaddr); | |
39c00dc2 | 943 | ssh_userauth2(local_user, server_user, host, sensitive); |
8ce64345 | 944 | } else { |
8ce64345 | 945 | ssh_kex(host, hostaddr); |
39c00dc2 | 946 | ssh_userauth1(local_user, server_user, host, sensitive); |
8ce64345 | 947 | } |
2b8dc5e3 | 948 | xfree(local_user); |
7b2ea3a1 | 949 | } |
0ae4fe1d | 950 | |
951 | void | |
952 | ssh_put_password(char *password) | |
953 | { | |
954 | int size; | |
955 | char *padded; | |
956 | ||
99c415db | 957 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
449c5ba5 | 958 | packet_put_cstring(password); |
99c415db | 959 | return; |
960 | } | |
0ae4fe1d | 961 | size = roundup(strlen(password) + 1, 32); |
52e3daed | 962 | padded = xcalloc(1, size); |
0ae4fe1d | 963 | strlcpy(padded, password, size); |
964 | packet_put_string(padded, size); | |
965 | memset(padded, 0, size); | |
966 | xfree(padded); | |
967 | } | |
8a48a7ef | 968 | |
969 | static int | |
970 | show_key_from_file(const char *file, const char *host, int keytype) | |
971 | { | |
972 | Key *found; | |
973 | char *fp; | |
974 | int line, ret; | |
975 | ||
976 | found = key_new(keytype); | |
977 | if ((ret = lookup_key_in_hostfile_by_type(file, host, | |
978 | keytype, found, &line))) { | |
979 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); | |
bbe88b6d | 980 | logit("WARNING: %s key found for host %s\n" |
567a05bf | 981 | "in %s:%d\n" |
8a48a7ef | 982 | "%s key fingerprint %s.", |
983 | key_type(found), host, file, line, | |
984 | key_type(found), fp); | |
985 | xfree(fp); | |
986 | } | |
987 | key_free(found); | |
988 | return (ret); | |
989 | } | |
990 | ||
991 | /* print all known host keys for a given host, but skip keys of given type */ | |
992 | static int | |
993 | show_other_keys(const char *host, Key *key) | |
994 | { | |
995 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; | |
996 | int i, found = 0; | |
997 | ||
998 | for (i = 0; type[i] != -1; i++) { | |
999 | if (type[i] == key->type) | |
1000 | continue; | |
1001 | if (type[i] != KEY_RSA1 && | |
1002 | show_key_from_file(options.user_hostfile2, host, type[i])) { | |
1003 | found = 1; | |
1004 | continue; | |
1005 | } | |
1006 | if (type[i] != KEY_RSA1 && | |
1007 | show_key_from_file(options.system_hostfile2, host, type[i])) { | |
1008 | found = 1; | |
1009 | continue; | |
1010 | } | |
1011 | if (show_key_from_file(options.user_hostfile, host, type[i])) { | |
1012 | found = 1; | |
1013 | continue; | |
1014 | } | |
1015 | if (show_key_from_file(options.system_hostfile, host, type[i])) { | |
1016 | found = 1; | |
1017 | continue; | |
1018 | } | |
1019 | debug2("no key of type %d for host %s", type[i], host); | |
1020 | } | |
1021 | return (found); | |
1022 | } | |
1a1bc5d5 | 1023 | |
1024 | static void | |
1025 | warn_changed_key(Key *host_key) | |
1026 | { | |
1027 | char *fp; | |
f5da7f70 | 1028 | const char *type = key_type(host_key); |
1a1bc5d5 | 1029 | |
1030 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); | |
1031 | ||
1032 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1033 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); | |
1034 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1035 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); | |
1036 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); | |
1037 | error("It is also possible that the %s host key has just been changed.", type); | |
1038 | error("The fingerprint for the %s key sent by the remote host is\n%s.", | |
1039 | type, fp); | |
1040 | error("Please contact your system administrator."); | |
1041 | ||
1042 | xfree(fp); | |
1a1bc5d5 | 1043 | } |
d20f3c9e | 1044 | |
1045 | /* | |
1046 | * Execute a local command | |
1047 | */ | |
1048 | int | |
1049 | ssh_local_cmd(const char *args) | |
1050 | { | |
1051 | char *shell; | |
1052 | pid_t pid; | |
1053 | int status; | |
1054 | ||
1055 | if (!options.permit_local_command || | |
1056 | args == NULL || !*args) | |
1057 | return (1); | |
1058 | ||
1059 | if ((shell = getenv("SHELL")) == NULL) | |
1060 | shell = _PATH_BSHELL; | |
1061 | ||
1062 | pid = fork(); | |
1063 | if (pid == 0) { | |
1064 | debug3("Executing %s -c \"%s\"", shell, args); | |
1065 | execl(shell, shell, "-c", args, (char *)NULL); | |
1066 | error("Couldn't execute %s -c \"%s\": %s", | |
1067 | shell, args, strerror(errno)); | |
1068 | _exit(1); | |
1069 | } else if (pid == -1) | |
1070 | fatal("fork failed: %.100s", strerror(errno)); | |
1071 | while (waitpid(pid, &status, 0) == -1) | |
1072 | if (errno != EINTR) | |
1073 | fatal("Couldn't wait for child: %s", strerror(errno)); | |
1074 | ||
1075 | if (!WIFEXITED(status)) | |
1076 | return (1); | |
1077 | ||
1078 | return (WEXITSTATUS(status)); | |
1079 | } |