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31652869 | 1 | /* $OpenBSD: sshconnect.c,v 1.199 2006/08/03 03:34:42 deraadt 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> |
e264ac72 | 22 | #ifdef HAVE_SYS_TIME_H |
23 | # include <sys/time.h> | |
24 | #endif | |
9794d008 | 25 | |
26 | #include <netinet/in.h> | |
a75f5360 | 27 | |
b6438382 | 28 | #include <ctype.h> |
028094f4 | 29 | #include <errno.h> |
28cb0a43 | 30 | #include <netdb.h> |
b5b88c19 | 31 | #ifdef HAVE_PATHS_H |
a75f5360 | 32 | #include <paths.h> |
b5b88c19 | 33 | #endif |
b1842393 | 34 | #include <pwd.h> |
cf851879 | 35 | #include <stdio.h> |
ffa517a8 | 36 | #include <stdlib.h> |
00146caa | 37 | #include <string.h> |
5188ba17 | 38 | #include <unistd.h> |
8efc0c15 | 39 | |
8efc0c15 | 40 | #include "xmalloc.h" |
31652869 | 41 | #include "key.h" |
42 | #include "hostfile.h" | |
43 | #include "ssh.h" | |
8efc0c15 | 44 | #include "rsa.h" |
8ce64345 | 45 | #include "buffer.h" |
8efc0c15 | 46 | #include "packet.h" |
8efc0c15 | 47 | #include "uidswap.h" |
48 | #include "compat.h" | |
4fe2af09 | 49 | #include "key.h" |
a306f2dd | 50 | #include "sshconnect.h" |
4fe2af09 | 51 | #include "hostfile.h" |
42f11eb2 | 52 | #include "log.h" |
53 | #include "readconf.h" | |
54 | #include "atomicio.h" | |
55 | #include "misc.h" | |
21289cd0 | 56 | #include "dns.h" |
28015df4 | 57 | #include "version.h" |
21289cd0 | 58 | |
a306f2dd | 59 | char *client_version_string = NULL; |
60 | char *server_version_string = NULL; | |
8ce64345 | 61 | |
ed82a2a9 | 62 | static int matching_host_key_dns = 0; |
1432b5c4 | 63 | |
3fb156df | 64 | /* import */ |
57112b5a | 65 | extern Options options; |
48e671d5 | 66 | extern char *__progname; |
3fb156df | 67 | extern uid_t original_real_uid; |
68 | extern uid_t original_effective_uid; | |
6939bbd4 | 69 | extern pid_t proxy_command_pid; |
57112b5a | 70 | |
a704dd54 | 71 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ |
72 | #define INET6_ADDRSTRLEN 46 | |
73 | #endif | |
74 | ||
8a48a7ef | 75 | static int show_other_keys(const char *, Key *); |
1a1bc5d5 | 76 | static void warn_changed_key(Key *); |
8a48a7ef | 77 | |
5260325f | 78 | /* |
79 | * Connect to the given ssh server using a proxy command. | |
80 | */ | |
396c147e | 81 | static int |
3fb156df | 82 | ssh_proxy_connect(const char *host, u_short port, const char *proxy_command) |
8efc0c15 | 83 | { |
a980cbd7 | 84 | char *command_string, *tmp; |
5260325f | 85 | int pin[2], pout[2]; |
9da5c3c9 | 86 | pid_t pid; |
48e671d5 | 87 | char strport[NI_MAXSERV]; |
5260325f | 88 | |
89 | /* Convert the port number into a string. */ | |
48e671d5 | 90 | snprintf(strport, sizeof strport, "%hu", port); |
5260325f | 91 | |
6939bbd4 | 92 | /* |
93 | * Build the final command string in the buffer by making the | |
94 | * appropriate substitutions to the given proxy command. | |
95 | * | |
aff51935 | 96 | * Use "exec" to avoid "sh -c" processes on some platforms |
6939bbd4 | 97 | * (e.g. Solaris) |
98 | */ | |
52e3daed | 99 | xasprintf(&tmp, "exec %s", proxy_command); |
a980cbd7 | 100 | command_string = percent_expand(tmp, "h", host, |
101 | "p", strport, (char *)NULL); | |
102 | xfree(tmp); | |
5260325f | 103 | |
104 | /* Create pipes for communicating with the proxy. */ | |
105 | if (pipe(pin) < 0 || pipe(pout) < 0) | |
106 | fatal("Could not create pipes to communicate with the proxy: %.100s", | |
184eed6a | 107 | strerror(errno)); |
5260325f | 108 | |
109 | debug("Executing proxy command: %.500s", command_string); | |
110 | ||
111 | /* Fork and execute the proxy command. */ | |
112 | if ((pid = fork()) == 0) { | |
113 | char *argv[10]; | |
114 | ||
115 | /* Child. Permanently give up superuser privileges. */ | |
3c33c1b6 | 116 | permanently_drop_suid(original_real_uid); |
5260325f | 117 | |
118 | /* Redirect stdin and stdout. */ | |
119 | close(pin[1]); | |
120 | if (pin[0] != 0) { | |
121 | if (dup2(pin[0], 0) < 0) | |
122 | perror("dup2 stdin"); | |
123 | close(pin[0]); | |
124 | } | |
125 | close(pout[0]); | |
126 | if (dup2(pout[1], 1) < 0) | |
127 | perror("dup2 stdout"); | |
128 | /* Cannot be 1 because pin allocated two descriptors. */ | |
129 | close(pout[1]); | |
130 | ||
131 | /* Stderr is left as it is so that error messages get | |
132 | printed on the user's terminal. */ | |
30228d7c | 133 | argv[0] = _PATH_BSHELL; |
5260325f | 134 | argv[1] = "-c"; |
135 | argv[2] = command_string; | |
136 | argv[3] = NULL; | |
137 | ||
138 | /* Execute the proxy command. Note that we gave up any | |
139 | extra privileges above. */ | |
328654d8 | 140 | execv(argv[0], argv); |
141 | perror(argv[0]); | |
5260325f | 142 | exit(1); |
8efc0c15 | 143 | } |
5260325f | 144 | /* Parent. */ |
145 | if (pid < 0) | |
146 | fatal("fork failed: %.100s", strerror(errno)); | |
6939bbd4 | 147 | else |
148 | proxy_command_pid = pid; /* save pid to clean up later */ | |
5260325f | 149 | |
150 | /* Close child side of the descriptors. */ | |
151 | close(pin[0]); | |
152 | close(pout[1]); | |
153 | ||
154 | /* Free the command name. */ | |
a980cbd7 | 155 | xfree(command_string); |
5260325f | 156 | |
157 | /* Set the connection file descriptors. */ | |
158 | packet_set_connection(pout[0], pin[1]); | |
8efc0c15 | 159 | |
ce773142 | 160 | /* Indicate OK return */ |
161 | return 0; | |
5260325f | 162 | } |
8efc0c15 | 163 | |
5260325f | 164 | /* |
165 | * Creates a (possibly privileged) socket for use as the ssh connection. | |
166 | */ | |
396c147e | 167 | static int |
3e131a6d | 168 | ssh_create_socket(int privileged, struct addrinfo *ai) |
8efc0c15 | 169 | { |
3435f5a6 | 170 | int sock, gaierr; |
171 | struct addrinfo hints, *res; | |
5260325f | 172 | |
aa3378df | 173 | /* |
174 | * If we are running as root and want to connect to a privileged | |
175 | * port, bind our own socket to a privileged port. | |
176 | */ | |
5260325f | 177 | if (privileged) { |
178 | int p = IPPORT_RESERVED - 1; | |
3fb156df | 179 | PRIV_START; |
3e131a6d | 180 | sock = rresvport_af(&p, ai->ai_family); |
3fb156df | 181 | PRIV_END; |
5260325f | 182 | if (sock < 0) |
3e131a6d | 183 | error("rresvport: af=%d %.100s", ai->ai_family, |
184 | strerror(errno)); | |
c8d54615 | 185 | else |
186 | debug("Allocated local port %d.", p); | |
3435f5a6 | 187 | return sock; |
188 | } | |
3e131a6d | 189 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3435f5a6 | 190 | if (sock < 0) |
191 | error("socket: %.100s", strerror(errno)); | |
3435f5a6 | 192 | |
193 | /* Bind the socket to an alternative local IP address */ | |
194 | if (options.bind_address == NULL) | |
195 | return sock; | |
196 | ||
197 | memset(&hints, 0, sizeof(hints)); | |
3e131a6d | 198 | hints.ai_family = ai->ai_family; |
199 | hints.ai_socktype = ai->ai_socktype; | |
200 | hints.ai_protocol = ai->ai_protocol; | |
3435f5a6 | 201 | hints.ai_flags = AI_PASSIVE; |
202 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); | |
203 | if (gaierr) { | |
204 | error("getaddrinfo: %s: %s", options.bind_address, | |
205 | gai_strerror(gaierr)); | |
206 | close(sock); | |
207 | return -1; | |
208 | } | |
209 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { | |
210 | error("bind: %s: %s", options.bind_address, strerror(errno)); | |
211 | close(sock); | |
212 | freeaddrinfo(res); | |
213 | return -1; | |
5260325f | 214 | } |
3435f5a6 | 215 | freeaddrinfo(res); |
5260325f | 216 | return sock; |
8efc0c15 | 217 | } |
218 | ||
09ab3296 | 219 | static int |
220 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, | |
221 | socklen_t addrlen, int timeout) | |
222 | { | |
223 | fd_set *fdset; | |
224 | struct timeval tv; | |
225 | socklen_t optlen; | |
52e3daed | 226 | int optval, rc, result = -1; |
09ab3296 | 227 | |
228 | if (timeout <= 0) | |
229 | return (connect(sockfd, serv_addr, addrlen)); | |
230 | ||
2daf1db1 | 231 | set_nonblock(sockfd); |
09ab3296 | 232 | rc = connect(sockfd, serv_addr, addrlen); |
2daf1db1 | 233 | if (rc == 0) { |
234 | unset_nonblock(sockfd); | |
09ab3296 | 235 | return (0); |
2daf1db1 | 236 | } |
09ab3296 | 237 | if (errno != EINPROGRESS) |
238 | return (-1); | |
239 | ||
52e3daed | 240 | fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS), |
241 | sizeof(fd_mask)); | |
09ab3296 | 242 | FD_SET(sockfd, fdset); |
243 | tv.tv_sec = timeout; | |
244 | tv.tv_usec = 0; | |
245 | ||
f8cc7664 | 246 | for (;;) { |
09ab3296 | 247 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
248 | if (rc != -1 || errno != EINTR) | |
249 | break; | |
250 | } | |
251 | ||
f8cc7664 | 252 | switch (rc) { |
09ab3296 | 253 | case 0: |
254 | /* Timed out */ | |
255 | errno = ETIMEDOUT; | |
da54f5be | 256 | break; |
09ab3296 | 257 | case -1: |
258 | /* Select error */ | |
aff51935 | 259 | debug("select: %s", strerror(errno)); |
da54f5be | 260 | break; |
09ab3296 | 261 | case 1: |
262 | /* Completed or failed */ | |
263 | optval = 0; | |
264 | optlen = sizeof(optval); | |
aff51935 | 265 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
ce26c02a | 266 | &optlen) == -1) { |
aff51935 | 267 | debug("getsockopt: %s", strerror(errno)); |
da54f5be | 268 | break; |
ce26c02a | 269 | } |
09ab3296 | 270 | if (optval != 0) { |
271 | errno = optval; | |
da54f5be | 272 | break; |
09ab3296 | 273 | } |
da54f5be | 274 | result = 0; |
2daf1db1 | 275 | unset_nonblock(sockfd); |
09ab3296 | 276 | break; |
277 | default: | |
278 | /* Should not occur */ | |
279 | fatal("Bogus return (%d) from select()", rc); | |
280 | } | |
281 | ||
da54f5be | 282 | xfree(fdset); |
283 | return (result); | |
09ab3296 | 284 | } |
285 | ||
5260325f | 286 | /* |
48e671d5 | 287 | * Opens a TCP/IP connection to the remote server on the given host. |
288 | * The address of the remote host will be returned in hostaddr. | |
3fb156df | 289 | * If port is 0, the default port will be used. If needpriv is true, |
5260325f | 290 | * a privileged port will be allocated to make the connection. |
3fb156df | 291 | * This requires super-user privileges if needpriv is true. |
5260325f | 292 | * Connection_attempts specifies the maximum number of tries (one per |
293 | * second). If proxy_command is non-NULL, it specifies the command (with %h | |
294 | * and %p substituted for host and port, respectively) to use to contact | |
295 | * the daemon. | |
296 | */ | |
297 | int | |
48e671d5 | 298 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
dab89049 | 299 | u_short port, int family, int connection_attempts, |
3fb156df | 300 | int needpriv, const char *proxy_command) |
8efc0c15 | 301 | { |
b5c334cc | 302 | int gaierr; |
303 | int on = 1; | |
48e671d5 | 304 | int sock = -1, attempt; |
48e671d5 | 305 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
b5c334cc | 306 | struct addrinfo hints, *ai, *aitop; |
5260325f | 307 | |
a77673cc | 308 | debug2("ssh_connect: needpriv %d", needpriv); |
5260325f | 309 | |
5260325f | 310 | /* If a proxy command is given, connect using it. */ |
311 | if (proxy_command != NULL) | |
3fb156df | 312 | return ssh_proxy_connect(host, port, proxy_command); |
5260325f | 313 | |
314 | /* No proxy command. */ | |
315 | ||
48e671d5 | 316 | memset(&hints, 0, sizeof(hints)); |
dab89049 | 317 | hints.ai_family = family; |
48e671d5 | 318 | hints.ai_socktype = SOCK_STREAM; |
d6133f43 | 319 | snprintf(strport, sizeof strport, "%u", port); |
48e671d5 | 320 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
321 | fatal("%s: %.100s: %s", __progname, host, | |
322 | gai_strerror(gaierr)); | |
5260325f | 323 | |
4439dde1 | 324 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
5260325f | 325 | if (attempt > 0) |
326 | debug("Trying again..."); | |
327 | ||
4439dde1 | 328 | /* |
329 | * Loop through addresses for this host, and try each one in | |
330 | * sequence until the connection succeeds. | |
331 | */ | |
48e671d5 | 332 | for (ai = aitop; ai; ai = ai->ai_next) { |
333 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
334 | continue; | |
335 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
336 | ntop, sizeof(ntop), strport, sizeof(strport), | |
337 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
338 | error("ssh_connect: getnameinfo failed"); | |
339 | continue; | |
340 | } | |
341 | debug("Connecting to %.200s [%.100s] port %s.", | |
342 | host, ntop, strport); | |
343 | ||
344 | /* Create a socket for connecting. */ | |
3e131a6d | 345 | sock = ssh_create_socket(needpriv, ai); |
48e671d5 | 346 | if (sock < 0) |
ce773142 | 347 | /* Any error is already output */ |
48e671d5 | 348 | continue; |
349 | ||
09ab3296 | 350 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
351 | options.connection_timeout) >= 0) { | |
48e671d5 | 352 | /* Successful connection. */ |
cd332296 | 353 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
5260325f | 354 | break; |
48e671d5 | 355 | } else { |
c750d869 | 356 | debug("connect to address %s port %s: %s", |
357 | ntop, strport, strerror(errno)); | |
5260325f | 358 | close(sock); |
4439dde1 | 359 | sock = -1; |
5260325f | 360 | } |
8efc0c15 | 361 | } |
4439dde1 | 362 | if (sock != -1) |
48e671d5 | 363 | break; /* Successful connection. */ |
8efc0c15 | 364 | |
5260325f | 365 | /* Sleep a moment before retrying. */ |
366 | sleep(1); | |
367 | } | |
48e671d5 | 368 | |
369 | freeaddrinfo(aitop); | |
370 | ||
5260325f | 371 | /* Return failure if we didn't get a successful connection. */ |
4439dde1 | 372 | if (sock == -1) { |
cf039bd1 | 373 | error("ssh: connect to host %s port %s: %s", |
9bd68577 | 374 | host, strport, strerror(errno)); |
cf039bd1 | 375 | return (-1); |
9bd68577 | 376 | } |
8efc0c15 | 377 | |
5260325f | 378 | debug("Connection established."); |
8efc0c15 | 379 | |
fd573618 | 380 | /* Set SO_KEEPALIVE if requested. */ |
381 | if (options.tcp_keep_alive && | |
b5c334cc | 382 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
383 | sizeof(on)) < 0) | |
384 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
8efc0c15 | 385 | |
5260325f | 386 | /* Set the connection. */ |
387 | packet_set_connection(sock, sock); | |
8efc0c15 | 388 | |
ce773142 | 389 | return 0; |
8efc0c15 | 390 | } |
391 | ||
5260325f | 392 | /* |
393 | * Waits for the server identification string, and sends our own | |
394 | * identification string. | |
395 | */ | |
396c147e | 396 | static void |
5ca51e19 | 397 | ssh_exchange_identification(void) |
8efc0c15 | 398 | { |
5260325f | 399 | char buf[256], remote_version[256]; /* must be same size! */ |
2ceb8101 | 400 | int remote_major, remote_minor, mismatch; |
5260325f | 401 | int connection_in = packet_get_connection_in(); |
402 | int connection_out = packet_get_connection_out(); | |
2b87da3b | 403 | int minor1 = PROTOCOL_MINOR_1; |
e5c76324 | 404 | u_int i, n; |
5260325f | 405 | |
05624c18 | 406 | /* Read other side's version identification. */ |
e5c76324 | 407 | for (n = 0;;) { |
38c295d6 | 408 | for (i = 0; i < sizeof(buf) - 1; i++) { |
05624c18 | 409 | size_t len = atomicio(read, connection_in, &buf[i], 1); |
410 | ||
56964485 | 411 | if (len != 1 && errno == EPIPE) |
38c295d6 | 412 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
05624c18 | 413 | else if (len != 1) |
414 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); | |
38c295d6 | 415 | if (buf[i] == '\r') { |
416 | buf[i] = '\n'; | |
417 | buf[i + 1] = 0; | |
418 | continue; /**XXX wait for \n */ | |
419 | } | |
420 | if (buf[i] == '\n') { | |
421 | buf[i + 1] = 0; | |
422 | break; | |
423 | } | |
e5c76324 | 424 | if (++n > 65536) |
425 | fatal("ssh_exchange_identification: No banner received"); | |
5260325f | 426 | } |
38c295d6 | 427 | buf[sizeof(buf) - 1] = 0; |
428 | if (strncmp(buf, "SSH-", 4) == 0) | |
5260325f | 429 | break; |
38c295d6 | 430 | debug("ssh_exchange_identification: %s", buf); |
8efc0c15 | 431 | } |
8ce64345 | 432 | server_version_string = xstrdup(buf); |
5260325f | 433 | |
aa3378df | 434 | /* |
435 | * Check that the versions match. In future this might accept | |
436 | * several versions and set appropriate flags to handle them. | |
437 | */ | |
8ce64345 | 438 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
439 | &remote_major, &remote_minor, remote_version) != 3) | |
5260325f | 440 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
441 | debug("Remote protocol version %d.%d, remote software version %.100s", | |
184eed6a | 442 | remote_major, remote_minor, remote_version); |
5260325f | 443 | |
8ce64345 | 444 | compat_datafellows(remote_version); |
a8be9f80 | 445 | mismatch = 0; |
446 | ||
6aacefa7 | 447 | switch (remote_major) { |
a8be9f80 | 448 | case 1: |
449 | if (remote_minor == 99 && | |
450 | (options.protocol & SSH_PROTO_2) && | |
451 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { | |
452 | enable_compat20(); | |
453 | break; | |
5260325f | 454 | } |
a8be9f80 | 455 | if (!(options.protocol & SSH_PROTO_1)) { |
456 | mismatch = 1; | |
457 | break; | |
458 | } | |
459 | if (remote_minor < 3) { | |
460 | fatal("Remote machine has too old SSH software version."); | |
fa08c86b | 461 | } else if (remote_minor == 3 || remote_minor == 4) { |
a8be9f80 | 462 | /* We speak 1.3, too. */ |
463 | enable_compat13(); | |
fa08c86b | 464 | minor1 = 3; |
a8be9f80 | 465 | if (options.forward_agent) { |
bbe88b6d | 466 | logit("Agent forwarding disabled for protocol 1.3"); |
a8be9f80 | 467 | options.forward_agent = 0; |
468 | } | |
469 | } | |
470 | break; | |
471 | case 2: | |
472 | if (options.protocol & SSH_PROTO_2) { | |
473 | enable_compat20(); | |
474 | break; | |
475 | } | |
476 | /* FALLTHROUGH */ | |
6ae2364d | 477 | default: |
a8be9f80 | 478 | mismatch = 1; |
479 | break; | |
8efc0c15 | 480 | } |
a8be9f80 | 481 | if (mismatch) |
5260325f | 482 | fatal("Protocol major versions differ: %d vs. %d", |
a8be9f80 | 483 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
484 | remote_major); | |
5260325f | 485 | /* Send our own protocol version identification. */ |
486 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | |
a8be9f80 | 487 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
fa08c86b | 488 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
8ce64345 | 489 | SSH_VERSION); |
dc54438a | 490 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
5260325f | 491 | fatal("write: %.100s", strerror(errno)); |
8ce64345 | 492 | client_version_string = xstrdup(buf); |
493 | chop(client_version_string); | |
494 | chop(server_version_string); | |
495 | debug("Local version string %.100s", client_version_string); | |
8efc0c15 | 496 | } |
497 | ||
f21032a6 | 498 | /* defaults to 'no' */ |
396c147e | 499 | static int |
a2c92c4a | 500 | confirm(const char *prompt) |
8efc0c15 | 501 | { |
616a6b93 | 502 | const char *msg, *again = "Please type 'yes' or 'no': "; |
503 | char *p; | |
504 | int ret = -1; | |
5260325f | 505 | |
f21032a6 | 506 | if (options.batch_mode) |
507 | return 0; | |
616a6b93 | 508 | for (msg = prompt;;msg = again) { |
509 | p = read_passphrase(msg, RP_ECHO); | |
510 | if (p == NULL || | |
511 | (p[0] == '\0') || (p[0] == '\n') || | |
512 | strncasecmp(p, "no", 2) == 0) | |
513 | ret = 0; | |
f11fe301 | 514 | if (p && strncasecmp(p, "yes", 3) == 0) |
616a6b93 | 515 | ret = 1; |
516 | if (p) | |
517 | xfree(p); | |
518 | if (ret != -1) | |
519 | return ret; | |
8efc0c15 | 520 | } |
8efc0c15 | 521 | } |
522 | ||
5260325f | 523 | /* |
f49bc4f7 | 524 | * check whether the supplied host key is valid, return -1 if the key |
525 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. | |
5260325f | 526 | */ |
331c3884 | 527 | #define RDRW 0 |
528 | #define RDONLY 1 | |
529 | #define ROQUIET 2 | |
396c147e | 530 | static int |
331c3884 | 531 | check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, |
532 | Key *host_key, int readonly, const char *user_hostfile, | |
533 | const char *system_hostfile) | |
8efc0c15 | 534 | { |
4fe2af09 | 535 | Key *file_key; |
b6c7b7b7 | 536 | const char *type = key_type(host_key); |
d4530052 | 537 | char *ip = NULL, *host = NULL; |
22138a36 | 538 | char hostline[1000], *hostp, *fp; |
5260325f | 539 | HostStatus host_status; |
540 | HostStatus ip_status; | |
e79276c2 | 541 | int r, local = 0, host_ip_differ = 0; |
20af321f | 542 | int salen; |
48e671d5 | 543 | char ntop[NI_MAXHOST]; |
616a6b93 | 544 | char msg[1024]; |
1432b5c4 | 545 | int len, host_line, ip_line; |
1e3b8b07 | 546 | const char *host_file = NULL, *ip_file = NULL; |
48e671d5 | 547 | |
548 | /* | |
549 | * Force accepting of the host key for loopback/localhost. The | |
550 | * problem is that if the home directory is NFS-mounted to multiple | |
551 | * machines, localhost will refer to a different machine in each of | |
552 | * them, and the user will get bogus HOST_CHANGED warnings. This | |
553 | * essentially disables host authentication for localhost; however, | |
554 | * this is probably not a real problem. | |
555 | */ | |
a306f2dd | 556 | /** hostaddr == 0! */ |
48e671d5 | 557 | switch (hostaddr->sa_family) { |
558 | case AF_INET: | |
f49bc4f7 | 559 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
4e2e5cfd | 560 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
20af321f | 561 | salen = sizeof(struct sockaddr_in); |
48e671d5 | 562 | break; |
563 | case AF_INET6: | |
f49bc4f7 | 564 | local = IN6_IS_ADDR_LOOPBACK( |
565 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | |
20af321f | 566 | salen = sizeof(struct sockaddr_in6); |
48e671d5 | 567 | break; |
568 | default: | |
569 | local = 0; | |
20af321f | 570 | salen = sizeof(struct sockaddr_storage); |
48e671d5 | 571 | break; |
572 | } | |
8bbc048a | 573 | if (options.no_host_authentication_for_localhost == 1 && local && |
574 | options.host_key_alias == NULL) { | |
7c49df64 | 575 | debug("Forcing accepting of host key for " |
576 | "loopback/localhost."); | |
f49bc4f7 | 577 | return 0; |
48e671d5 | 578 | } |
5260325f | 579 | |
57112b5a | 580 | /* |
7c49df64 | 581 | * We don't have the remote ip-address for connections |
582 | * using a proxy command | |
583 | */ | |
584 | if (options.proxy_command == NULL) { | |
585 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), | |
586 | NULL, 0, NI_NUMERICHOST) != 0) | |
587 | fatal("check_host_key: getnameinfo failed"); | |
331c3884 | 588 | ip = put_host_port(ntop, port); |
7c49df64 | 589 | } else { |
590 | ip = xstrdup("<no hostip for proxy command>"); | |
591 | } | |
592 | /* | |
593 | * Turn off check_host_ip if the connection is to localhost, via proxy | |
594 | * command or if we don't have a hostname to compare with | |
57112b5a | 595 | */ |
d4530052 | 596 | if (options.check_host_ip && (local || |
597 | strcmp(hostname, ip) == 0 || options.proxy_command != NULL)) | |
57112b5a | 598 | options.check_host_ip = 0; |
599 | ||
8abcdba4 | 600 | /* |
d4530052 | 601 | * Allow the user to record the key under a different name or |
602 | * differentiate a non-standard port. This is useful for ssh | |
603 | * tunneling over forwarded connections or if you run multiple | |
604 | * sshd's on different ports on the same machine. | |
8abcdba4 | 605 | */ |
606 | if (options.host_key_alias != NULL) { | |
d4530052 | 607 | host = xstrdup(options.host_key_alias); |
8abcdba4 | 608 | debug("using hostkeyalias: %s", host); |
d4530052 | 609 | } else { |
331c3884 | 610 | host = put_host_port(hostname, port); |
8abcdba4 | 611 | } |
612 | ||
95f1eccc | 613 | /* |
614 | * Store the host key from the known host file in here so that we can | |
615 | * compare it with the key for the IP address. | |
616 | */ | |
4fe2af09 | 617 | file_key = key_new(host_key->type); |
5260325f | 618 | |
aa3378df | 619 | /* |
7b9b0103 | 620 | * Check if the host key is present in the user's list of known |
aa3378df | 621 | * hosts or in the systemwide list. |
622 | */ | |
1e3b8b07 | 623 | host_file = user_hostfile; |
f49bc4f7 | 624 | host_status = check_host_in_hostfile(host_file, host, host_key, |
184eed6a | 625 | file_key, &host_line); |
1e3b8b07 | 626 | if (host_status == HOST_NEW) { |
627 | host_file = system_hostfile; | |
f49bc4f7 | 628 | host_status = check_host_in_hostfile(host_file, host, host_key, |
629 | file_key, &host_line); | |
1e3b8b07 | 630 | } |
aa3378df | 631 | /* |
632 | * Also perform check for the ip address, skip the check if we are | |
633 | * localhost or the hostname was an ip address to begin with | |
634 | */ | |
7c49df64 | 635 | if (options.check_host_ip) { |
4fe2af09 | 636 | Key *ip_key = key_new(host_key->type); |
5260325f | 637 | |
1e3b8b07 | 638 | ip_file = user_hostfile; |
f49bc4f7 | 639 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
640 | ip_key, &ip_line); | |
1e3b8b07 | 641 | if (ip_status == HOST_NEW) { |
642 | ip_file = system_hostfile; | |
f49bc4f7 | 643 | ip_status = check_host_in_hostfile(ip_file, ip, |
644 | host_key, ip_key, &ip_line); | |
1e3b8b07 | 645 | } |
5260325f | 646 | if (host_status == HOST_CHANGED && |
4fe2af09 | 647 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
5260325f | 648 | host_ip_differ = 1; |
649 | ||
4fe2af09 | 650 | key_free(ip_key); |
5260325f | 651 | } else |
652 | ip_status = host_status; | |
653 | ||
4fe2af09 | 654 | key_free(file_key); |
5260325f | 655 | |
656 | switch (host_status) { | |
657 | case HOST_OK: | |
658 | /* The host is known and the key matches. */ | |
1d1ffb87 | 659 | debug("Host '%.200s' is known and matches the %s host key.", |
660 | host, type); | |
1e3b8b07 | 661 | debug("Found key in %s:%d", host_file, host_line); |
7c49df64 | 662 | if (options.check_host_ip && ip_status == HOST_NEW) { |
f49bc4f7 | 663 | if (readonly) |
bbe88b6d | 664 | logit("%s host key for IP address " |
f49bc4f7 | 665 | "'%.128s' not in list of known hosts.", |
7c49df64 | 666 | type, ip); |
f49bc4f7 | 667 | else if (!add_host_to_hostfile(user_hostfile, ip, |
5c63c2ab | 668 | host_key, options.hash_known_hosts)) |
bbe88b6d | 669 | logit("Failed to add the %s host key for IP " |
f49bc4f7 | 670 | "address '%.128s' to the list of known " |
671 | "hosts (%.30s).", type, ip, user_hostfile); | |
672 | else | |
bbe88b6d | 673 | logit("Warning: Permanently added the %s host " |
f49bc4f7 | 674 | "key for IP address '%.128s' to the list " |
675 | "of known hosts.", type, ip); | |
5260325f | 676 | } |
677 | break; | |
678 | case HOST_NEW: | |
331c3884 | 679 | if (options.host_key_alias == NULL && port != 0 && |
680 | port != SSH_DEFAULT_PORT) { | |
681 | debug("checking without port identifier"); | |
682 | if (check_host_key(hostname, hostaddr, 0, host_key, 2, | |
683 | user_hostfile, system_hostfile) == 0) { | |
684 | debug("found matching key w/out port"); | |
685 | break; | |
686 | } | |
687 | } | |
f49bc4f7 | 688 | if (readonly) |
689 | goto fail; | |
5260325f | 690 | /* The host is new. */ |
691 | if (options.strict_host_key_checking == 1) { | |
f49bc4f7 | 692 | /* |
693 | * User has requested strict host key checking. We | |
694 | * will not add the host key automatically. The only | |
695 | * alternative left is to abort. | |
696 | */ | |
697 | error("No %s host key is known for %.200s and you " | |
698 | "have requested strict checking.", type, host); | |
699 | goto fail; | |
5260325f | 700 | } else if (options.strict_host_key_checking == 2) { |
1432b5c4 | 701 | char msg1[1024], msg2[1024]; |
702 | ||
703 | if (show_other_keys(host, host_key)) | |
704 | snprintf(msg1, sizeof(msg1), | |
4e2e5cfd | 705 | "\nbut keys of different type are already" |
706 | " known for this host."); | |
1432b5c4 | 707 | else |
708 | snprintf(msg1, sizeof(msg1), "."); | |
5260325f | 709 | /* The default */ |
22138a36 | 710 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
1432b5c4 | 711 | msg2[0] = '\0'; |
1432b5c4 | 712 | if (options.verify_host_key_dns) { |
0161a13d | 713 | if (matching_host_key_dns) |
1432b5c4 | 714 | snprintf(msg2, sizeof(msg2), |
715 | "Matching host key fingerprint" | |
716 | " found in DNS.\n"); | |
717 | else | |
718 | snprintf(msg2, sizeof(msg2), | |
719 | "No matching host key fingerprint" | |
720 | " found in DNS.\n"); | |
721 | } | |
616a6b93 | 722 | snprintf(msg, sizeof(msg), |
f49bc4f7 | 723 | "The authenticity of host '%.200s (%s)' can't be " |
8a48a7ef | 724 | "established%s\n" |
1432b5c4 | 725 | "%s key fingerprint is %s.\n%s" |
f49bc4f7 | 726 | "Are you sure you want to continue connecting " |
8a48a7ef | 727 | "(yes/no)? ", |
1432b5c4 | 728 | host, ip, msg1, type, fp, msg2); |
22138a36 | 729 | xfree(fp); |
616a6b93 | 730 | if (!confirm(msg)) |
f49bc4f7 | 731 | goto fail; |
5260325f | 732 | } |
f49bc4f7 | 733 | /* |
734 | * If not in strict mode, add the key automatically to the | |
735 | * local known_hosts file. | |
736 | */ | |
e79276c2 | 737 | if (options.check_host_ip && ip_status == HOST_NEW) { |
738 | snprintf(hostline, sizeof(hostline), "%s,%s", | |
739 | host, ip); | |
740 | hostp = hostline; | |
741 | if (options.hash_known_hosts) { | |
742 | /* Add hash of host and IP separately */ | |
743 | r = add_host_to_hostfile(user_hostfile, host, | |
744 | host_key, options.hash_known_hosts) && | |
745 | add_host_to_hostfile(user_hostfile, ip, | |
746 | host_key, options.hash_known_hosts); | |
747 | } else { | |
748 | /* Add unhashed "host,ip" */ | |
749 | r = add_host_to_hostfile(user_hostfile, | |
750 | hostline, host_key, | |
751 | options.hash_known_hosts); | |
752 | } | |
753 | } else { | |
754 | r = add_host_to_hostfile(user_hostfile, host, host_key, | |
755 | options.hash_known_hosts); | |
756 | hostp = host; | |
757 | } | |
758 | ||
759 | if (!r) | |
bbe88b6d | 760 | logit("Failed to add the host to the list of known " |
f49bc4f7 | 761 | "hosts (%.500s).", user_hostfile); |
5260325f | 762 | else |
bbe88b6d | 763 | logit("Warning: Permanently added '%.200s' (%s) to the " |
f49bc4f7 | 764 | "list of known hosts.", hostp, type); |
5260325f | 765 | break; |
766 | case HOST_CHANGED: | |
331c3884 | 767 | if (readonly == ROQUIET) |
768 | goto fail; | |
5260325f | 769 | if (options.check_host_ip && host_ip_differ) { |
ca75d7de | 770 | char *key_msg; |
5260325f | 771 | if (ip_status == HOST_NEW) |
ca75d7de | 772 | key_msg = "is unknown"; |
5260325f | 773 | else if (ip_status == HOST_OK) |
ca75d7de | 774 | key_msg = "is unchanged"; |
5260325f | 775 | else |
ca75d7de | 776 | key_msg = "has a different value"; |
5260325f | 777 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
778 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); | |
779 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1d1ffb87 | 780 | error("The %s host key for %s has changed,", type, host); |
5260325f | 781 | error("and the key for the according IP address %s", ip); |
ca75d7de | 782 | error("%s. This could either mean that", key_msg); |
5260325f | 783 | error("DNS SPOOFING is happening or the IP address for the host"); |
1e3b8b07 | 784 | error("and its host key have changed at the same time."); |
7c49df64 | 785 | if (ip_status != HOST_NEW) |
1e3b8b07 | 786 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
5260325f | 787 | } |
788 | /* The host key has changed. */ | |
1a1bc5d5 | 789 | warn_changed_key(host_key); |
5260325f | 790 | error("Add correct host key in %.100s to get rid of this message.", |
8abcdba4 | 791 | user_hostfile); |
1e3b8b07 | 792 | error("Offending key in %s:%d", host_file, host_line); |
5260325f | 793 | |
aa3378df | 794 | /* |
795 | * If strict host key checking is in use, the user will have | |
796 | * to edit the key manually and we can only abort. | |
797 | */ | |
f49bc4f7 | 798 | if (options.strict_host_key_checking) { |
799 | error("%s host key for %.200s has changed and you have " | |
800 | "requested strict checking.", type, host); | |
801 | goto fail; | |
802 | } | |
5260325f | 803 | |
aa3378df | 804 | /* |
805 | * If strict host key checking has not been requested, allow | |
d453a600 | 806 | * the connection but without MITM-able authentication or |
fee76795 | 807 | * forwarding. |
aa3378df | 808 | */ |
5260325f | 809 | if (options.password_authentication) { |
f49bc4f7 | 810 | error("Password authentication is disabled to avoid " |
811 | "man-in-the-middle attacks."); | |
5260325f | 812 | options.password_authentication = 0; |
813 | } | |
d453a600 | 814 | if (options.kbd_interactive_authentication) { |
815 | error("Keyboard-interactive authentication is disabled" | |
816 | " to avoid man-in-the-middle attacks."); | |
817 | options.kbd_interactive_authentication = 0; | |
818 | options.challenge_response_authentication = 0; | |
819 | } | |
820 | if (options.challenge_response_authentication) { | |
821 | error("Challenge/response authentication is disabled" | |
822 | " to avoid man-in-the-middle attacks."); | |
823 | options.challenge_response_authentication = 0; | |
824 | } | |
5260325f | 825 | if (options.forward_agent) { |
f49bc4f7 | 826 | error("Agent forwarding is disabled to avoid " |
827 | "man-in-the-middle attacks."); | |
5260325f | 828 | options.forward_agent = 0; |
829 | } | |
0b6fbf03 | 830 | if (options.forward_x11) { |
f49bc4f7 | 831 | error("X11 forwarding is disabled to avoid " |
832 | "man-in-the-middle attacks."); | |
0b6fbf03 | 833 | options.forward_x11 = 0; |
834 | } | |
f49bc4f7 | 835 | if (options.num_local_forwards > 0 || |
836 | options.num_remote_forwards > 0) { | |
837 | error("Port forwarding is disabled to avoid " | |
838 | "man-in-the-middle attacks."); | |
839 | options.num_local_forwards = | |
184eed6a | 840 | options.num_remote_forwards = 0; |
0b6fbf03 | 841 | } |
fee76795 | 842 | if (options.tun_open != SSH_TUNMODE_NO) { |
843 | error("Tunnel forwarding is disabled to avoid " | |
844 | "man-in-the-middle attacks."); | |
845 | options.tun_open = SSH_TUNMODE_NO; | |
846 | } | |
aa3378df | 847 | /* |
848 | * XXX Should permit the user to change to use the new id. | |
849 | * This could be done by converting the host key to an | |
850 | * identifying sentence, tell that the host identifies itself | |
851 | * by that sentence, and ask the user if he/she whishes to | |
852 | * accept the authentication. | |
853 | */ | |
5260325f | 854 | break; |
8a48a7ef | 855 | case HOST_FOUND: |
856 | fatal("internal error"); | |
857 | break; | |
5260325f | 858 | } |
0b6fbf03 | 859 | |
7c49df64 | 860 | if (options.check_host_ip && host_status != HOST_CHANGED && |
861 | ip_status == HOST_CHANGED) { | |
616a6b93 | 862 | snprintf(msg, sizeof(msg), |
863 | "Warning: the %s host key for '%.200s' " | |
864 | "differs from the key for the IP address '%.128s'" | |
865 | "\nOffending key for IP in %s:%d", | |
866 | type, host, ip, ip_file, ip_line); | |
867 | if (host_status == HOST_OK) { | |
868 | len = strlen(msg); | |
869 | snprintf(msg + len, sizeof(msg) - len, | |
870 | "\nMatching host key in %s:%d", | |
7203d6bb | 871 | host_file, host_line); |
616a6b93 | 872 | } |
7c49df64 | 873 | if (options.strict_host_key_checking == 1) { |
b0545fe6 | 874 | logit("%s", msg); |
f49bc4f7 | 875 | error("Exiting, you have requested strict checking."); |
876 | goto fail; | |
7c49df64 | 877 | } else if (options.strict_host_key_checking == 2) { |
616a6b93 | 878 | strlcat(msg, "\nAre you sure you want " |
879 | "to continue connecting (yes/no)? ", sizeof(msg)); | |
880 | if (!confirm(msg)) | |
f49bc4f7 | 881 | goto fail; |
616a6b93 | 882 | } else { |
b0545fe6 | 883 | logit("%s", msg); |
7c49df64 | 884 | } |
885 | } | |
886 | ||
0b6fbf03 | 887 | xfree(ip); |
d4530052 | 888 | xfree(host); |
f49bc4f7 | 889 | return 0; |
890 | ||
891 | fail: | |
892 | xfree(ip); | |
d4530052 | 893 | xfree(host); |
f49bc4f7 | 894 | return -1; |
895 | } | |
896 | ||
21289cd0 | 897 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
f49bc4f7 | 898 | int |
899 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) | |
900 | { | |
901 | struct stat st; | |
0161a13d | 902 | int flags = 0; |
f49bc4f7 | 903 | |
0161a13d | 904 | if (options.verify_host_key_dns && |
905 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { | |
906 | ||
907 | if (flags & DNS_VERIFY_FOUND) { | |
908 | ||
909 | if (options.verify_host_key_dns == 1 && | |
910 | flags & DNS_VERIFY_MATCH && | |
911 | flags & DNS_VERIFY_SECURE) | |
912 | return 0; | |
913 | ||
914 | if (flags & DNS_VERIFY_MATCH) { | |
915 | matching_host_key_dns = 1; | |
916 | } else { | |
917 | warn_changed_key(host_key); | |
918 | error("Update the SSHFP RR in DNS with the new " | |
919 | "host key to get rid of this message."); | |
920 | } | |
21289cd0 | 921 | } |
922 | } | |
21289cd0 | 923 | |
f49bc4f7 | 924 | /* return ok if the key can be found in an old keyfile */ |
925 | if (stat(options.system_hostfile2, &st) == 0 || | |
926 | stat(options.user_hostfile2, &st) == 0) { | |
331c3884 | 927 | if (check_host_key(host, hostaddr, options.port, host_key, |
928 | RDONLY, options.user_hostfile2, | |
929 | options.system_hostfile2) == 0) | |
f49bc4f7 | 930 | return 0; |
931 | } | |
331c3884 | 932 | return check_host_key(host, hostaddr, options.port, host_key, |
933 | RDRW, options.user_hostfile, options.system_hostfile); | |
95f1eccc | 934 | } |
935 | ||
8ce64345 | 936 | /* |
a306f2dd | 937 | * Starts a dialog with the server, and authenticates the current user on the |
938 | * server. This does not need any extra privileges. The basic connection | |
939 | * to the server must already have been established before this is called. | |
940 | * If login fails, this function prints an error and never returns. | |
941 | * This function does not require super-user privileges. | |
8ce64345 | 942 | */ |
943 | void | |
39c00dc2 | 944 | ssh_login(Sensitive *sensitive, const char *orighost, |
63bd8c36 | 945 | struct sockaddr *hostaddr, struct passwd *pw) |
8ce64345 | 946 | { |
a306f2dd | 947 | char *host, *cp; |
8ce64345 | 948 | char *server_user, *local_user; |
8ce64345 | 949 | |
8ce64345 | 950 | local_user = xstrdup(pw->pw_name); |
951 | server_user = options.user ? options.user : local_user; | |
952 | ||
7b2ea3a1 | 953 | /* Convert the user-supplied hostname into all lowercase. */ |
954 | host = xstrdup(orighost); | |
955 | for (cp = host; *cp; cp++) | |
956 | if (isupper(*cp)) | |
9555d258 | 957 | *cp = (char)tolower(*cp); |
7b2ea3a1 | 958 | |
959 | /* Exchange protocol version identification strings with the server. */ | |
960 | ssh_exchange_identification(); | |
961 | ||
962 | /* Put the connection into non-blocking mode. */ | |
963 | packet_set_nonblocking(); | |
964 | ||
7b2ea3a1 | 965 | /* key exchange */ |
7b2ea3a1 | 966 | /* authenticate user */ |
8ce64345 | 967 | if (compat20) { |
968 | ssh_kex2(host, hostaddr); | |
39c00dc2 | 969 | ssh_userauth2(local_user, server_user, host, sensitive); |
8ce64345 | 970 | } else { |
8ce64345 | 971 | ssh_kex(host, hostaddr); |
39c00dc2 | 972 | ssh_userauth1(local_user, server_user, host, sensitive); |
8ce64345 | 973 | } |
2b8dc5e3 | 974 | xfree(local_user); |
7b2ea3a1 | 975 | } |
0ae4fe1d | 976 | |
977 | void | |
978 | ssh_put_password(char *password) | |
979 | { | |
980 | int size; | |
981 | char *padded; | |
982 | ||
99c415db | 983 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
449c5ba5 | 984 | packet_put_cstring(password); |
99c415db | 985 | return; |
986 | } | |
0ae4fe1d | 987 | size = roundup(strlen(password) + 1, 32); |
52e3daed | 988 | padded = xcalloc(1, size); |
0ae4fe1d | 989 | strlcpy(padded, password, size); |
990 | packet_put_string(padded, size); | |
991 | memset(padded, 0, size); | |
992 | xfree(padded); | |
993 | } | |
8a48a7ef | 994 | |
995 | static int | |
996 | show_key_from_file(const char *file, const char *host, int keytype) | |
997 | { | |
998 | Key *found; | |
999 | char *fp; | |
1000 | int line, ret; | |
1001 | ||
1002 | found = key_new(keytype); | |
1003 | if ((ret = lookup_key_in_hostfile_by_type(file, host, | |
1004 | keytype, found, &line))) { | |
1005 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); | |
bbe88b6d | 1006 | logit("WARNING: %s key found for host %s\n" |
567a05bf | 1007 | "in %s:%d\n" |
8a48a7ef | 1008 | "%s key fingerprint %s.", |
1009 | key_type(found), host, file, line, | |
1010 | key_type(found), fp); | |
1011 | xfree(fp); | |
1012 | } | |
1013 | key_free(found); | |
1014 | return (ret); | |
1015 | } | |
1016 | ||
1017 | /* print all known host keys for a given host, but skip keys of given type */ | |
1018 | static int | |
1019 | show_other_keys(const char *host, Key *key) | |
1020 | { | |
1021 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; | |
1022 | int i, found = 0; | |
1023 | ||
1024 | for (i = 0; type[i] != -1; i++) { | |
1025 | if (type[i] == key->type) | |
1026 | continue; | |
1027 | if (type[i] != KEY_RSA1 && | |
1028 | show_key_from_file(options.user_hostfile2, host, type[i])) { | |
1029 | found = 1; | |
1030 | continue; | |
1031 | } | |
1032 | if (type[i] != KEY_RSA1 && | |
1033 | show_key_from_file(options.system_hostfile2, host, type[i])) { | |
1034 | found = 1; | |
1035 | continue; | |
1036 | } | |
1037 | if (show_key_from_file(options.user_hostfile, host, type[i])) { | |
1038 | found = 1; | |
1039 | continue; | |
1040 | } | |
1041 | if (show_key_from_file(options.system_hostfile, host, type[i])) { | |
1042 | found = 1; | |
1043 | continue; | |
1044 | } | |
1045 | debug2("no key of type %d for host %s", type[i], host); | |
1046 | } | |
1047 | return (found); | |
1048 | } | |
1a1bc5d5 | 1049 | |
1050 | static void | |
1051 | warn_changed_key(Key *host_key) | |
1052 | { | |
1053 | char *fp; | |
f5da7f70 | 1054 | const char *type = key_type(host_key); |
1a1bc5d5 | 1055 | |
1056 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); | |
1057 | ||
1058 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1059 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); | |
1060 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1061 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); | |
1062 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); | |
1063 | error("It is also possible that the %s host key has just been changed.", type); | |
1064 | error("The fingerprint for the %s key sent by the remote host is\n%s.", | |
1065 | type, fp); | |
1066 | error("Please contact your system administrator."); | |
1067 | ||
1068 | xfree(fp); | |
1a1bc5d5 | 1069 | } |
d20f3c9e | 1070 | |
1071 | /* | |
1072 | * Execute a local command | |
1073 | */ | |
1074 | int | |
1075 | ssh_local_cmd(const char *args) | |
1076 | { | |
1077 | char *shell; | |
1078 | pid_t pid; | |
1079 | int status; | |
1080 | ||
1081 | if (!options.permit_local_command || | |
1082 | args == NULL || !*args) | |
1083 | return (1); | |
1084 | ||
1085 | if ((shell = getenv("SHELL")) == NULL) | |
1086 | shell = _PATH_BSHELL; | |
1087 | ||
1088 | pid = fork(); | |
1089 | if (pid == 0) { | |
1090 | debug3("Executing %s -c \"%s\"", shell, args); | |
1091 | execl(shell, shell, "-c", args, (char *)NULL); | |
1092 | error("Couldn't execute %s -c \"%s\": %s", | |
1093 | shell, args, strerror(errno)); | |
1094 | _exit(1); | |
1095 | } else if (pid == -1) | |
1096 | fatal("fork failed: %.100s", strerror(errno)); | |
1097 | while (waitpid(pid, &status, 0) == -1) | |
1098 | if (errno != EINTR) | |
1099 | fatal("Couldn't wait for child: %s", strerror(errno)); | |
1100 | ||
1101 | if (!WIFEXITED(status)) | |
1102 | return (1); | |
1103 | ||
1104 | return (WEXITSTATUS(status)); | |
1105 | } |