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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> | |
5e837c7b | 27 | #include <arpa/inet.h> |
a75f5360 | 28 | |
b6438382 | 29 | #include <ctype.h> |
028094f4 | 30 | #include <errno.h> |
28cb0a43 | 31 | #include <netdb.h> |
b5b88c19 | 32 | #ifdef HAVE_PATHS_H |
a75f5360 | 33 | #include <paths.h> |
b5b88c19 | 34 | #endif |
b1842393 | 35 | #include <pwd.h> |
24436b92 | 36 | #include <stdarg.h> |
cf851879 | 37 | #include <stdio.h> |
ffa517a8 | 38 | #include <stdlib.h> |
00146caa | 39 | #include <string.h> |
5188ba17 | 40 | #include <unistd.h> |
8efc0c15 | 41 | |
8efc0c15 | 42 | #include "xmalloc.h" |
31652869 | 43 | #include "key.h" |
44 | #include "hostfile.h" | |
45 | #include "ssh.h" | |
8efc0c15 | 46 | #include "rsa.h" |
8ce64345 | 47 | #include "buffer.h" |
8efc0c15 | 48 | #include "packet.h" |
8efc0c15 | 49 | #include "uidswap.h" |
50 | #include "compat.h" | |
4fe2af09 | 51 | #include "key.h" |
a306f2dd | 52 | #include "sshconnect.h" |
4fe2af09 | 53 | #include "hostfile.h" |
42f11eb2 | 54 | #include "log.h" |
55 | #include "readconf.h" | |
56 | #include "atomicio.h" | |
57 | #include "misc.h" | |
21289cd0 | 58 | #include "dns.h" |
28015df4 | 59 | #include "version.h" |
21289cd0 | 60 | |
a306f2dd | 61 | char *client_version_string = NULL; |
62 | char *server_version_string = NULL; | |
8ce64345 | 63 | |
ed82a2a9 | 64 | static int matching_host_key_dns = 0; |
1432b5c4 | 65 | |
3fb156df | 66 | /* import */ |
57112b5a | 67 | extern Options options; |
48e671d5 | 68 | extern char *__progname; |
3fb156df | 69 | extern uid_t original_real_uid; |
70 | extern uid_t original_effective_uid; | |
6939bbd4 | 71 | extern pid_t proxy_command_pid; |
57112b5a | 72 | |
a704dd54 | 73 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ |
74 | #define INET6_ADDRSTRLEN 46 | |
75 | #endif | |
76 | ||
8a48a7ef | 77 | static int show_other_keys(const char *, Key *); |
1a1bc5d5 | 78 | static void warn_changed_key(Key *); |
8a48a7ef | 79 | |
5260325f | 80 | /* |
81 | * Connect to the given ssh server using a proxy command. | |
82 | */ | |
396c147e | 83 | static int |
3fb156df | 84 | ssh_proxy_connect(const char *host, u_short port, const char *proxy_command) |
8efc0c15 | 85 | { |
a980cbd7 | 86 | char *command_string, *tmp; |
5260325f | 87 | int pin[2], pout[2]; |
9da5c3c9 | 88 | pid_t pid; |
48e671d5 | 89 | char strport[NI_MAXSERV]; |
5260325f | 90 | |
91 | /* Convert the port number into a string. */ | |
48e671d5 | 92 | snprintf(strport, sizeof strport, "%hu", port); |
5260325f | 93 | |
6939bbd4 | 94 | /* |
95 | * Build the final command string in the buffer by making the | |
96 | * appropriate substitutions to the given proxy command. | |
97 | * | |
aff51935 | 98 | * Use "exec" to avoid "sh -c" processes on some platforms |
6939bbd4 | 99 | * (e.g. Solaris) |
100 | */ | |
52e3daed | 101 | xasprintf(&tmp, "exec %s", proxy_command); |
a980cbd7 | 102 | command_string = percent_expand(tmp, "h", host, |
103 | "p", strport, (char *)NULL); | |
104 | xfree(tmp); | |
5260325f | 105 | |
106 | /* Create pipes for communicating with the proxy. */ | |
107 | if (pipe(pin) < 0 || pipe(pout) < 0) | |
108 | fatal("Could not create pipes to communicate with the proxy: %.100s", | |
184eed6a | 109 | strerror(errno)); |
5260325f | 110 | |
111 | debug("Executing proxy command: %.500s", command_string); | |
112 | ||
113 | /* Fork and execute the proxy command. */ | |
114 | if ((pid = fork()) == 0) { | |
115 | char *argv[10]; | |
116 | ||
117 | /* Child. Permanently give up superuser privileges. */ | |
3c33c1b6 | 118 | permanently_drop_suid(original_real_uid); |
5260325f | 119 | |
120 | /* Redirect stdin and stdout. */ | |
121 | close(pin[1]); | |
122 | if (pin[0] != 0) { | |
123 | if (dup2(pin[0], 0) < 0) | |
124 | perror("dup2 stdin"); | |
125 | close(pin[0]); | |
126 | } | |
127 | close(pout[0]); | |
128 | if (dup2(pout[1], 1) < 0) | |
129 | perror("dup2 stdout"); | |
130 | /* Cannot be 1 because pin allocated two descriptors. */ | |
131 | close(pout[1]); | |
132 | ||
133 | /* Stderr is left as it is so that error messages get | |
134 | printed on the user's terminal. */ | |
30228d7c | 135 | argv[0] = _PATH_BSHELL; |
5260325f | 136 | argv[1] = "-c"; |
137 | argv[2] = command_string; | |
138 | argv[3] = NULL; | |
139 | ||
140 | /* Execute the proxy command. Note that we gave up any | |
141 | extra privileges above. */ | |
328654d8 | 142 | execv(argv[0], argv); |
143 | perror(argv[0]); | |
5260325f | 144 | exit(1); |
8efc0c15 | 145 | } |
5260325f | 146 | /* Parent. */ |
147 | if (pid < 0) | |
148 | fatal("fork failed: %.100s", strerror(errno)); | |
6939bbd4 | 149 | else |
150 | proxy_command_pid = pid; /* save pid to clean up later */ | |
5260325f | 151 | |
152 | /* Close child side of the descriptors. */ | |
153 | close(pin[0]); | |
154 | close(pout[1]); | |
155 | ||
156 | /* Free the command name. */ | |
a980cbd7 | 157 | xfree(command_string); |
5260325f | 158 | |
159 | /* Set the connection file descriptors. */ | |
160 | packet_set_connection(pout[0], pin[1]); | |
8efc0c15 | 161 | |
ce773142 | 162 | /* Indicate OK return */ |
163 | return 0; | |
5260325f | 164 | } |
8efc0c15 | 165 | |
5260325f | 166 | /* |
167 | * Creates a (possibly privileged) socket for use as the ssh connection. | |
168 | */ | |
396c147e | 169 | static int |
3e131a6d | 170 | ssh_create_socket(int privileged, struct addrinfo *ai) |
8efc0c15 | 171 | { |
3435f5a6 | 172 | int sock, gaierr; |
173 | struct addrinfo hints, *res; | |
5260325f | 174 | |
aa3378df | 175 | /* |
176 | * If we are running as root and want to connect to a privileged | |
177 | * port, bind our own socket to a privileged port. | |
178 | */ | |
5260325f | 179 | if (privileged) { |
180 | int p = IPPORT_RESERVED - 1; | |
3fb156df | 181 | PRIV_START; |
3e131a6d | 182 | sock = rresvport_af(&p, ai->ai_family); |
3fb156df | 183 | PRIV_END; |
5260325f | 184 | if (sock < 0) |
3e131a6d | 185 | error("rresvport: af=%d %.100s", ai->ai_family, |
186 | strerror(errno)); | |
c8d54615 | 187 | else |
188 | debug("Allocated local port %d.", p); | |
3435f5a6 | 189 | return sock; |
190 | } | |
3e131a6d | 191 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3435f5a6 | 192 | if (sock < 0) |
193 | error("socket: %.100s", strerror(errno)); | |
3435f5a6 | 194 | |
195 | /* Bind the socket to an alternative local IP address */ | |
196 | if (options.bind_address == NULL) | |
197 | return sock; | |
198 | ||
199 | memset(&hints, 0, sizeof(hints)); | |
3e131a6d | 200 | hints.ai_family = ai->ai_family; |
201 | hints.ai_socktype = ai->ai_socktype; | |
202 | hints.ai_protocol = ai->ai_protocol; | |
3435f5a6 | 203 | hints.ai_flags = AI_PASSIVE; |
204 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); | |
205 | if (gaierr) { | |
206 | error("getaddrinfo: %s: %s", options.bind_address, | |
207 | gai_strerror(gaierr)); | |
208 | close(sock); | |
209 | return -1; | |
210 | } | |
211 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { | |
212 | error("bind: %s: %s", options.bind_address, strerror(errno)); | |
213 | close(sock); | |
214 | freeaddrinfo(res); | |
215 | return -1; | |
5260325f | 216 | } |
3435f5a6 | 217 | freeaddrinfo(res); |
5260325f | 218 | return sock; |
8efc0c15 | 219 | } |
220 | ||
09ab3296 | 221 | static int |
222 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, | |
223 | socklen_t addrlen, int timeout) | |
224 | { | |
225 | fd_set *fdset; | |
226 | struct timeval tv; | |
227 | socklen_t optlen; | |
52e3daed | 228 | int optval, rc, result = -1; |
09ab3296 | 229 | |
230 | if (timeout <= 0) | |
231 | return (connect(sockfd, serv_addr, addrlen)); | |
232 | ||
2daf1db1 | 233 | set_nonblock(sockfd); |
09ab3296 | 234 | rc = connect(sockfd, serv_addr, addrlen); |
2daf1db1 | 235 | if (rc == 0) { |
236 | unset_nonblock(sockfd); | |
09ab3296 | 237 | return (0); |
2daf1db1 | 238 | } |
09ab3296 | 239 | if (errno != EINPROGRESS) |
240 | return (-1); | |
241 | ||
52e3daed | 242 | fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS), |
243 | sizeof(fd_mask)); | |
09ab3296 | 244 | FD_SET(sockfd, fdset); |
245 | tv.tv_sec = timeout; | |
246 | tv.tv_usec = 0; | |
247 | ||
f8cc7664 | 248 | for (;;) { |
09ab3296 | 249 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); |
250 | if (rc != -1 || errno != EINTR) | |
251 | break; | |
252 | } | |
253 | ||
f8cc7664 | 254 | switch (rc) { |
09ab3296 | 255 | case 0: |
256 | /* Timed out */ | |
257 | errno = ETIMEDOUT; | |
da54f5be | 258 | break; |
09ab3296 | 259 | case -1: |
260 | /* Select error */ | |
aff51935 | 261 | debug("select: %s", strerror(errno)); |
da54f5be | 262 | break; |
09ab3296 | 263 | case 1: |
264 | /* Completed or failed */ | |
265 | optval = 0; | |
266 | optlen = sizeof(optval); | |
aff51935 | 267 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
ce26c02a | 268 | &optlen) == -1) { |
aff51935 | 269 | debug("getsockopt: %s", strerror(errno)); |
da54f5be | 270 | break; |
ce26c02a | 271 | } |
09ab3296 | 272 | if (optval != 0) { |
273 | errno = optval; | |
da54f5be | 274 | break; |
09ab3296 | 275 | } |
da54f5be | 276 | result = 0; |
2daf1db1 | 277 | unset_nonblock(sockfd); |
09ab3296 | 278 | break; |
279 | default: | |
280 | /* Should not occur */ | |
281 | fatal("Bogus return (%d) from select()", rc); | |
282 | } | |
283 | ||
da54f5be | 284 | xfree(fdset); |
285 | return (result); | |
09ab3296 | 286 | } |
287 | ||
5260325f | 288 | /* |
48e671d5 | 289 | * Opens a TCP/IP connection to the remote server on the given host. |
290 | * The address of the remote host will be returned in hostaddr. | |
3fb156df | 291 | * If port is 0, the default port will be used. If needpriv is true, |
5260325f | 292 | * a privileged port will be allocated to make the connection. |
3fb156df | 293 | * This requires super-user privileges if needpriv is true. |
5260325f | 294 | * Connection_attempts specifies the maximum number of tries (one per |
295 | * second). If proxy_command is non-NULL, it specifies the command (with %h | |
296 | * and %p substituted for host and port, respectively) to use to contact | |
297 | * the daemon. | |
298 | */ | |
299 | int | |
48e671d5 | 300 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
dab89049 | 301 | u_short port, int family, int connection_attempts, |
3fb156df | 302 | int needpriv, const char *proxy_command) |
8efc0c15 | 303 | { |
b5c334cc | 304 | int gaierr; |
305 | int on = 1; | |
48e671d5 | 306 | int sock = -1, attempt; |
48e671d5 | 307 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
b5c334cc | 308 | struct addrinfo hints, *ai, *aitop; |
5260325f | 309 | |
a77673cc | 310 | debug2("ssh_connect: needpriv %d", needpriv); |
5260325f | 311 | |
5260325f | 312 | /* If a proxy command is given, connect using it. */ |
313 | if (proxy_command != NULL) | |
3fb156df | 314 | return ssh_proxy_connect(host, port, proxy_command); |
5260325f | 315 | |
316 | /* No proxy command. */ | |
317 | ||
48e671d5 | 318 | memset(&hints, 0, sizeof(hints)); |
dab89049 | 319 | hints.ai_family = family; |
48e671d5 | 320 | hints.ai_socktype = SOCK_STREAM; |
d6133f43 | 321 | snprintf(strport, sizeof strport, "%u", port); |
48e671d5 | 322 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
323 | fatal("%s: %.100s: %s", __progname, host, | |
324 | gai_strerror(gaierr)); | |
5260325f | 325 | |
4439dde1 | 326 | for (attempt = 0; attempt < connection_attempts; attempt++) { |
5260325f | 327 | if (attempt > 0) |
328 | debug("Trying again..."); | |
329 | ||
4439dde1 | 330 | /* |
331 | * Loop through addresses for this host, and try each one in | |
332 | * sequence until the connection succeeds. | |
333 | */ | |
48e671d5 | 334 | for (ai = aitop; ai; ai = ai->ai_next) { |
335 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
336 | continue; | |
337 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
338 | ntop, sizeof(ntop), strport, sizeof(strport), | |
339 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
340 | error("ssh_connect: getnameinfo failed"); | |
341 | continue; | |
342 | } | |
343 | debug("Connecting to %.200s [%.100s] port %s.", | |
344 | host, ntop, strport); | |
345 | ||
346 | /* Create a socket for connecting. */ | |
3e131a6d | 347 | sock = ssh_create_socket(needpriv, ai); |
48e671d5 | 348 | if (sock < 0) |
ce773142 | 349 | /* Any error is already output */ |
48e671d5 | 350 | continue; |
351 | ||
09ab3296 | 352 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
353 | options.connection_timeout) >= 0) { | |
48e671d5 | 354 | /* Successful connection. */ |
cd332296 | 355 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
5260325f | 356 | break; |
48e671d5 | 357 | } else { |
c750d869 | 358 | debug("connect to address %s port %s: %s", |
359 | ntop, strport, strerror(errno)); | |
5260325f | 360 | close(sock); |
4439dde1 | 361 | sock = -1; |
5260325f | 362 | } |
8efc0c15 | 363 | } |
4439dde1 | 364 | if (sock != -1) |
48e671d5 | 365 | break; /* Successful connection. */ |
8efc0c15 | 366 | |
5260325f | 367 | /* Sleep a moment before retrying. */ |
368 | sleep(1); | |
369 | } | |
48e671d5 | 370 | |
371 | freeaddrinfo(aitop); | |
372 | ||
5260325f | 373 | /* Return failure if we didn't get a successful connection. */ |
4439dde1 | 374 | if (sock == -1) { |
cf039bd1 | 375 | error("ssh: connect to host %s port %s: %s", |
9bd68577 | 376 | host, strport, strerror(errno)); |
cf039bd1 | 377 | return (-1); |
9bd68577 | 378 | } |
8efc0c15 | 379 | |
5260325f | 380 | debug("Connection established."); |
8efc0c15 | 381 | |
fd573618 | 382 | /* Set SO_KEEPALIVE if requested. */ |
383 | if (options.tcp_keep_alive && | |
b5c334cc | 384 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
385 | sizeof(on)) < 0) | |
386 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
8efc0c15 | 387 | |
5260325f | 388 | /* Set the connection. */ |
389 | packet_set_connection(sock, sock); | |
8efc0c15 | 390 | |
ce773142 | 391 | return 0; |
8efc0c15 | 392 | } |
393 | ||
5260325f | 394 | /* |
395 | * Waits for the server identification string, and sends our own | |
396 | * identification string. | |
397 | */ | |
396c147e | 398 | static void |
5ca51e19 | 399 | ssh_exchange_identification(void) |
8efc0c15 | 400 | { |
5260325f | 401 | char buf[256], remote_version[256]; /* must be same size! */ |
2ceb8101 | 402 | int remote_major, remote_minor, mismatch; |
5260325f | 403 | int connection_in = packet_get_connection_in(); |
404 | int connection_out = packet_get_connection_out(); | |
2b87da3b | 405 | int minor1 = PROTOCOL_MINOR_1; |
e5c76324 | 406 | u_int i, n; |
5260325f | 407 | |
05624c18 | 408 | /* Read other side's version identification. */ |
e5c76324 | 409 | for (n = 0;;) { |
38c295d6 | 410 | for (i = 0; i < sizeof(buf) - 1; i++) { |
05624c18 | 411 | size_t len = atomicio(read, connection_in, &buf[i], 1); |
412 | ||
56964485 | 413 | if (len != 1 && errno == EPIPE) |
38c295d6 | 414 | fatal("ssh_exchange_identification: Connection closed by remote host"); |
05624c18 | 415 | else if (len != 1) |
416 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); | |
38c295d6 | 417 | if (buf[i] == '\r') { |
418 | buf[i] = '\n'; | |
419 | buf[i + 1] = 0; | |
420 | continue; /**XXX wait for \n */ | |
421 | } | |
422 | if (buf[i] == '\n') { | |
423 | buf[i + 1] = 0; | |
424 | break; | |
425 | } | |
e5c76324 | 426 | if (++n > 65536) |
427 | fatal("ssh_exchange_identification: No banner received"); | |
5260325f | 428 | } |
38c295d6 | 429 | buf[sizeof(buf) - 1] = 0; |
430 | if (strncmp(buf, "SSH-", 4) == 0) | |
5260325f | 431 | break; |
38c295d6 | 432 | debug("ssh_exchange_identification: %s", buf); |
8efc0c15 | 433 | } |
8ce64345 | 434 | server_version_string = xstrdup(buf); |
5260325f | 435 | |
aa3378df | 436 | /* |
437 | * Check that the versions match. In future this might accept | |
438 | * several versions and set appropriate flags to handle them. | |
439 | */ | |
8ce64345 | 440 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
441 | &remote_major, &remote_minor, remote_version) != 3) | |
5260325f | 442 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
443 | debug("Remote protocol version %d.%d, remote software version %.100s", | |
184eed6a | 444 | remote_major, remote_minor, remote_version); |
5260325f | 445 | |
8ce64345 | 446 | compat_datafellows(remote_version); |
a8be9f80 | 447 | mismatch = 0; |
448 | ||
6aacefa7 | 449 | switch (remote_major) { |
a8be9f80 | 450 | case 1: |
451 | if (remote_minor == 99 && | |
452 | (options.protocol & SSH_PROTO_2) && | |
453 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { | |
454 | enable_compat20(); | |
455 | break; | |
5260325f | 456 | } |
a8be9f80 | 457 | if (!(options.protocol & SSH_PROTO_1)) { |
458 | mismatch = 1; | |
459 | break; | |
460 | } | |
461 | if (remote_minor < 3) { | |
462 | fatal("Remote machine has too old SSH software version."); | |
fa08c86b | 463 | } else if (remote_minor == 3 || remote_minor == 4) { |
a8be9f80 | 464 | /* We speak 1.3, too. */ |
465 | enable_compat13(); | |
fa08c86b | 466 | minor1 = 3; |
a8be9f80 | 467 | if (options.forward_agent) { |
bbe88b6d | 468 | logit("Agent forwarding disabled for protocol 1.3"); |
a8be9f80 | 469 | options.forward_agent = 0; |
470 | } | |
471 | } | |
472 | break; | |
473 | case 2: | |
474 | if (options.protocol & SSH_PROTO_2) { | |
475 | enable_compat20(); | |
476 | break; | |
477 | } | |
478 | /* FALLTHROUGH */ | |
6ae2364d | 479 | default: |
a8be9f80 | 480 | mismatch = 1; |
481 | break; | |
8efc0c15 | 482 | } |
a8be9f80 | 483 | if (mismatch) |
5260325f | 484 | fatal("Protocol major versions differ: %d vs. %d", |
a8be9f80 | 485 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
486 | remote_major); | |
5260325f | 487 | /* Send our own protocol version identification. */ |
488 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | |
a8be9f80 | 489 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
fa08c86b | 490 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
8ce64345 | 491 | SSH_VERSION); |
dc54438a | 492 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
5260325f | 493 | fatal("write: %.100s", strerror(errno)); |
8ce64345 | 494 | client_version_string = xstrdup(buf); |
495 | chop(client_version_string); | |
496 | chop(server_version_string); | |
497 | debug("Local version string %.100s", client_version_string); | |
8efc0c15 | 498 | } |
499 | ||
f21032a6 | 500 | /* defaults to 'no' */ |
396c147e | 501 | static int |
a2c92c4a | 502 | confirm(const char *prompt) |
8efc0c15 | 503 | { |
616a6b93 | 504 | const char *msg, *again = "Please type 'yes' or 'no': "; |
505 | char *p; | |
506 | int ret = -1; | |
5260325f | 507 | |
f21032a6 | 508 | if (options.batch_mode) |
509 | return 0; | |
616a6b93 | 510 | for (msg = prompt;;msg = again) { |
511 | p = read_passphrase(msg, RP_ECHO); | |
512 | if (p == NULL || | |
513 | (p[0] == '\0') || (p[0] == '\n') || | |
514 | strncasecmp(p, "no", 2) == 0) | |
515 | ret = 0; | |
f11fe301 | 516 | if (p && strncasecmp(p, "yes", 3) == 0) |
616a6b93 | 517 | ret = 1; |
518 | if (p) | |
519 | xfree(p); | |
520 | if (ret != -1) | |
521 | return ret; | |
8efc0c15 | 522 | } |
8efc0c15 | 523 | } |
524 | ||
5260325f | 525 | /* |
f49bc4f7 | 526 | * check whether the supplied host key is valid, return -1 if the key |
527 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. | |
5260325f | 528 | */ |
331c3884 | 529 | #define RDRW 0 |
530 | #define RDONLY 1 | |
531 | #define ROQUIET 2 | |
396c147e | 532 | static int |
331c3884 | 533 | check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, |
534 | Key *host_key, int readonly, const char *user_hostfile, | |
535 | const char *system_hostfile) | |
8efc0c15 | 536 | { |
4fe2af09 | 537 | Key *file_key; |
b6c7b7b7 | 538 | const char *type = key_type(host_key); |
d4530052 | 539 | char *ip = NULL, *host = NULL; |
22138a36 | 540 | char hostline[1000], *hostp, *fp; |
5260325f | 541 | HostStatus host_status; |
542 | HostStatus ip_status; | |
e79276c2 | 543 | int r, local = 0, host_ip_differ = 0; |
20af321f | 544 | int salen; |
48e671d5 | 545 | char ntop[NI_MAXHOST]; |
616a6b93 | 546 | char msg[1024]; |
1432b5c4 | 547 | int len, host_line, ip_line; |
1e3b8b07 | 548 | const char *host_file = NULL, *ip_file = NULL; |
48e671d5 | 549 | |
550 | /* | |
551 | * Force accepting of the host key for loopback/localhost. The | |
552 | * problem is that if the home directory is NFS-mounted to multiple | |
553 | * machines, localhost will refer to a different machine in each of | |
554 | * them, and the user will get bogus HOST_CHANGED warnings. This | |
555 | * essentially disables host authentication for localhost; however, | |
556 | * this is probably not a real problem. | |
557 | */ | |
a306f2dd | 558 | /** hostaddr == 0! */ |
48e671d5 | 559 | switch (hostaddr->sa_family) { |
560 | case AF_INET: | |
f49bc4f7 | 561 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
4e2e5cfd | 562 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
20af321f | 563 | salen = sizeof(struct sockaddr_in); |
48e671d5 | 564 | break; |
565 | case AF_INET6: | |
f49bc4f7 | 566 | local = IN6_IS_ADDR_LOOPBACK( |
567 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | |
20af321f | 568 | salen = sizeof(struct sockaddr_in6); |
48e671d5 | 569 | break; |
570 | default: | |
571 | local = 0; | |
20af321f | 572 | salen = sizeof(struct sockaddr_storage); |
48e671d5 | 573 | break; |
574 | } | |
8bbc048a | 575 | if (options.no_host_authentication_for_localhost == 1 && local && |
576 | options.host_key_alias == NULL) { | |
7c49df64 | 577 | debug("Forcing accepting of host key for " |
578 | "loopback/localhost."); | |
f49bc4f7 | 579 | return 0; |
48e671d5 | 580 | } |
5260325f | 581 | |
57112b5a | 582 | /* |
7c49df64 | 583 | * We don't have the remote ip-address for connections |
584 | * using a proxy command | |
585 | */ | |
586 | if (options.proxy_command == NULL) { | |
587 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), | |
588 | NULL, 0, NI_NUMERICHOST) != 0) | |
589 | fatal("check_host_key: getnameinfo failed"); | |
331c3884 | 590 | ip = put_host_port(ntop, port); |
7c49df64 | 591 | } else { |
592 | ip = xstrdup("<no hostip for proxy command>"); | |
593 | } | |
594 | /* | |
595 | * Turn off check_host_ip if the connection is to localhost, via proxy | |
596 | * command or if we don't have a hostname to compare with | |
57112b5a | 597 | */ |
d4530052 | 598 | if (options.check_host_ip && (local || |
599 | strcmp(hostname, ip) == 0 || options.proxy_command != NULL)) | |
57112b5a | 600 | options.check_host_ip = 0; |
601 | ||
8abcdba4 | 602 | /* |
d4530052 | 603 | * Allow the user to record the key under a different name or |
604 | * differentiate a non-standard port. This is useful for ssh | |
605 | * tunneling over forwarded connections or if you run multiple | |
606 | * sshd's on different ports on the same machine. | |
8abcdba4 | 607 | */ |
608 | if (options.host_key_alias != NULL) { | |
d4530052 | 609 | host = xstrdup(options.host_key_alias); |
8abcdba4 | 610 | debug("using hostkeyalias: %s", host); |
d4530052 | 611 | } else { |
331c3884 | 612 | host = put_host_port(hostname, port); |
8abcdba4 | 613 | } |
614 | ||
95f1eccc | 615 | /* |
616 | * Store the host key from the known host file in here so that we can | |
617 | * compare it with the key for the IP address. | |
618 | */ | |
4fe2af09 | 619 | file_key = key_new(host_key->type); |
5260325f | 620 | |
aa3378df | 621 | /* |
7b9b0103 | 622 | * Check if the host key is present in the user's list of known |
aa3378df | 623 | * hosts or in the systemwide list. |
624 | */ | |
1e3b8b07 | 625 | host_file = user_hostfile; |
f49bc4f7 | 626 | host_status = check_host_in_hostfile(host_file, host, host_key, |
184eed6a | 627 | file_key, &host_line); |
1e3b8b07 | 628 | if (host_status == HOST_NEW) { |
629 | host_file = system_hostfile; | |
f49bc4f7 | 630 | host_status = check_host_in_hostfile(host_file, host, host_key, |
631 | file_key, &host_line); | |
1e3b8b07 | 632 | } |
aa3378df | 633 | /* |
634 | * Also perform check for the ip address, skip the check if we are | |
635 | * localhost or the hostname was an ip address to begin with | |
636 | */ | |
7c49df64 | 637 | if (options.check_host_ip) { |
4fe2af09 | 638 | Key *ip_key = key_new(host_key->type); |
5260325f | 639 | |
1e3b8b07 | 640 | ip_file = user_hostfile; |
f49bc4f7 | 641 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
642 | ip_key, &ip_line); | |
1e3b8b07 | 643 | if (ip_status == HOST_NEW) { |
644 | ip_file = system_hostfile; | |
f49bc4f7 | 645 | ip_status = check_host_in_hostfile(ip_file, ip, |
646 | host_key, ip_key, &ip_line); | |
1e3b8b07 | 647 | } |
5260325f | 648 | if (host_status == HOST_CHANGED && |
4fe2af09 | 649 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
5260325f | 650 | host_ip_differ = 1; |
651 | ||
4fe2af09 | 652 | key_free(ip_key); |
5260325f | 653 | } else |
654 | ip_status = host_status; | |
655 | ||
4fe2af09 | 656 | key_free(file_key); |
5260325f | 657 | |
658 | switch (host_status) { | |
659 | case HOST_OK: | |
660 | /* The host is known and the key matches. */ | |
1d1ffb87 | 661 | debug("Host '%.200s' is known and matches the %s host key.", |
662 | host, type); | |
1e3b8b07 | 663 | debug("Found key in %s:%d", host_file, host_line); |
7c49df64 | 664 | if (options.check_host_ip && ip_status == HOST_NEW) { |
f49bc4f7 | 665 | if (readonly) |
bbe88b6d | 666 | logit("%s host key for IP address " |
f49bc4f7 | 667 | "'%.128s' not in list of known hosts.", |
7c49df64 | 668 | type, ip); |
f49bc4f7 | 669 | else if (!add_host_to_hostfile(user_hostfile, ip, |
5c63c2ab | 670 | host_key, options.hash_known_hosts)) |
bbe88b6d | 671 | logit("Failed to add the %s host key for IP " |
f49bc4f7 | 672 | "address '%.128s' to the list of known " |
673 | "hosts (%.30s).", type, ip, user_hostfile); | |
674 | else | |
bbe88b6d | 675 | logit("Warning: Permanently added the %s host " |
f49bc4f7 | 676 | "key for IP address '%.128s' to the list " |
677 | "of known hosts.", type, ip); | |
5260325f | 678 | } |
679 | break; | |
680 | case HOST_NEW: | |
331c3884 | 681 | if (options.host_key_alias == NULL && port != 0 && |
682 | port != SSH_DEFAULT_PORT) { | |
683 | debug("checking without port identifier"); | |
684 | if (check_host_key(hostname, hostaddr, 0, host_key, 2, | |
685 | user_hostfile, system_hostfile) == 0) { | |
686 | debug("found matching key w/out port"); | |
687 | break; | |
688 | } | |
689 | } | |
f49bc4f7 | 690 | if (readonly) |
691 | goto fail; | |
5260325f | 692 | /* The host is new. */ |
693 | if (options.strict_host_key_checking == 1) { | |
f49bc4f7 | 694 | /* |
695 | * User has requested strict host key checking. We | |
696 | * will not add the host key automatically. The only | |
697 | * alternative left is to abort. | |
698 | */ | |
699 | error("No %s host key is known for %.200s and you " | |
700 | "have requested strict checking.", type, host); | |
701 | goto fail; | |
5260325f | 702 | } else if (options.strict_host_key_checking == 2) { |
1432b5c4 | 703 | char msg1[1024], msg2[1024]; |
704 | ||
705 | if (show_other_keys(host, host_key)) | |
706 | snprintf(msg1, sizeof(msg1), | |
4e2e5cfd | 707 | "\nbut keys of different type are already" |
708 | " known for this host."); | |
1432b5c4 | 709 | else |
710 | snprintf(msg1, sizeof(msg1), "."); | |
5260325f | 711 | /* The default */ |
22138a36 | 712 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
1432b5c4 | 713 | msg2[0] = '\0'; |
1432b5c4 | 714 | if (options.verify_host_key_dns) { |
0161a13d | 715 | if (matching_host_key_dns) |
1432b5c4 | 716 | snprintf(msg2, sizeof(msg2), |
717 | "Matching host key fingerprint" | |
718 | " found in DNS.\n"); | |
719 | else | |
720 | snprintf(msg2, sizeof(msg2), | |
721 | "No matching host key fingerprint" | |
722 | " found in DNS.\n"); | |
723 | } | |
616a6b93 | 724 | snprintf(msg, sizeof(msg), |
f49bc4f7 | 725 | "The authenticity of host '%.200s (%s)' can't be " |
8a48a7ef | 726 | "established%s\n" |
1432b5c4 | 727 | "%s key fingerprint is %s.\n%s" |
f49bc4f7 | 728 | "Are you sure you want to continue connecting " |
8a48a7ef | 729 | "(yes/no)? ", |
1432b5c4 | 730 | host, ip, msg1, type, fp, msg2); |
22138a36 | 731 | xfree(fp); |
616a6b93 | 732 | if (!confirm(msg)) |
f49bc4f7 | 733 | goto fail; |
5260325f | 734 | } |
f49bc4f7 | 735 | /* |
736 | * If not in strict mode, add the key automatically to the | |
737 | * local known_hosts file. | |
738 | */ | |
e79276c2 | 739 | if (options.check_host_ip && ip_status == HOST_NEW) { |
740 | snprintf(hostline, sizeof(hostline), "%s,%s", | |
741 | host, ip); | |
742 | hostp = hostline; | |
743 | if (options.hash_known_hosts) { | |
744 | /* Add hash of host and IP separately */ | |
745 | r = add_host_to_hostfile(user_hostfile, host, | |
746 | host_key, options.hash_known_hosts) && | |
747 | add_host_to_hostfile(user_hostfile, ip, | |
748 | host_key, options.hash_known_hosts); | |
749 | } else { | |
750 | /* Add unhashed "host,ip" */ | |
751 | r = add_host_to_hostfile(user_hostfile, | |
752 | hostline, host_key, | |
753 | options.hash_known_hosts); | |
754 | } | |
755 | } else { | |
756 | r = add_host_to_hostfile(user_hostfile, host, host_key, | |
757 | options.hash_known_hosts); | |
758 | hostp = host; | |
759 | } | |
760 | ||
761 | if (!r) | |
bbe88b6d | 762 | logit("Failed to add the host to the list of known " |
f49bc4f7 | 763 | "hosts (%.500s).", user_hostfile); |
5260325f | 764 | else |
bbe88b6d | 765 | logit("Warning: Permanently added '%.200s' (%s) to the " |
f49bc4f7 | 766 | "list of known hosts.", hostp, type); |
5260325f | 767 | break; |
768 | case HOST_CHANGED: | |
331c3884 | 769 | if (readonly == ROQUIET) |
770 | goto fail; | |
5260325f | 771 | if (options.check_host_ip && host_ip_differ) { |
ca75d7de | 772 | char *key_msg; |
5260325f | 773 | if (ip_status == HOST_NEW) |
ca75d7de | 774 | key_msg = "is unknown"; |
5260325f | 775 | else if (ip_status == HOST_OK) |
ca75d7de | 776 | key_msg = "is unchanged"; |
5260325f | 777 | else |
ca75d7de | 778 | key_msg = "has a different value"; |
5260325f | 779 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); |
780 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); | |
781 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1d1ffb87 | 782 | error("The %s host key for %s has changed,", type, host); |
5260325f | 783 | error("and the key for the according IP address %s", ip); |
ca75d7de | 784 | error("%s. This could either mean that", key_msg); |
5260325f | 785 | error("DNS SPOOFING is happening or the IP address for the host"); |
1e3b8b07 | 786 | error("and its host key have changed at the same time."); |
7c49df64 | 787 | if (ip_status != HOST_NEW) |
1e3b8b07 | 788 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
5260325f | 789 | } |
790 | /* The host key has changed. */ | |
1a1bc5d5 | 791 | warn_changed_key(host_key); |
5260325f | 792 | error("Add correct host key in %.100s to get rid of this message.", |
8abcdba4 | 793 | user_hostfile); |
1e3b8b07 | 794 | error("Offending key in %s:%d", host_file, host_line); |
5260325f | 795 | |
aa3378df | 796 | /* |
797 | * If strict host key checking is in use, the user will have | |
798 | * to edit the key manually and we can only abort. | |
799 | */ | |
f49bc4f7 | 800 | if (options.strict_host_key_checking) { |
801 | error("%s host key for %.200s has changed and you have " | |
802 | "requested strict checking.", type, host); | |
803 | goto fail; | |
804 | } | |
5260325f | 805 | |
aa3378df | 806 | /* |
807 | * If strict host key checking has not been requested, allow | |
d453a600 | 808 | * the connection but without MITM-able authentication or |
fee76795 | 809 | * forwarding. |
aa3378df | 810 | */ |
5260325f | 811 | if (options.password_authentication) { |
f49bc4f7 | 812 | error("Password authentication is disabled to avoid " |
813 | "man-in-the-middle attacks."); | |
5260325f | 814 | options.password_authentication = 0; |
815 | } | |
d453a600 | 816 | if (options.kbd_interactive_authentication) { |
817 | error("Keyboard-interactive authentication is disabled" | |
818 | " to avoid man-in-the-middle attacks."); | |
819 | options.kbd_interactive_authentication = 0; | |
820 | options.challenge_response_authentication = 0; | |
821 | } | |
822 | if (options.challenge_response_authentication) { | |
823 | error("Challenge/response authentication is disabled" | |
824 | " to avoid man-in-the-middle attacks."); | |
825 | options.challenge_response_authentication = 0; | |
826 | } | |
5260325f | 827 | if (options.forward_agent) { |
f49bc4f7 | 828 | error("Agent forwarding is disabled to avoid " |
829 | "man-in-the-middle attacks."); | |
5260325f | 830 | options.forward_agent = 0; |
831 | } | |
0b6fbf03 | 832 | if (options.forward_x11) { |
f49bc4f7 | 833 | error("X11 forwarding is disabled to avoid " |
834 | "man-in-the-middle attacks."); | |
0b6fbf03 | 835 | options.forward_x11 = 0; |
836 | } | |
f49bc4f7 | 837 | if (options.num_local_forwards > 0 || |
838 | options.num_remote_forwards > 0) { | |
839 | error("Port forwarding is disabled to avoid " | |
840 | "man-in-the-middle attacks."); | |
841 | options.num_local_forwards = | |
184eed6a | 842 | options.num_remote_forwards = 0; |
0b6fbf03 | 843 | } |
fee76795 | 844 | if (options.tun_open != SSH_TUNMODE_NO) { |
845 | error("Tunnel forwarding is disabled to avoid " | |
846 | "man-in-the-middle attacks."); | |
847 | options.tun_open = SSH_TUNMODE_NO; | |
848 | } | |
aa3378df | 849 | /* |
850 | * XXX Should permit the user to change to use the new id. | |
851 | * This could be done by converting the host key to an | |
852 | * identifying sentence, tell that the host identifies itself | |
853 | * by that sentence, and ask the user if he/she whishes to | |
854 | * accept the authentication. | |
855 | */ | |
5260325f | 856 | break; |
8a48a7ef | 857 | case HOST_FOUND: |
858 | fatal("internal error"); | |
859 | break; | |
5260325f | 860 | } |
0b6fbf03 | 861 | |
7c49df64 | 862 | if (options.check_host_ip && host_status != HOST_CHANGED && |
863 | ip_status == HOST_CHANGED) { | |
616a6b93 | 864 | snprintf(msg, sizeof(msg), |
865 | "Warning: the %s host key for '%.200s' " | |
866 | "differs from the key for the IP address '%.128s'" | |
867 | "\nOffending key for IP in %s:%d", | |
868 | type, host, ip, ip_file, ip_line); | |
869 | if (host_status == HOST_OK) { | |
870 | len = strlen(msg); | |
871 | snprintf(msg + len, sizeof(msg) - len, | |
872 | "\nMatching host key in %s:%d", | |
7203d6bb | 873 | host_file, host_line); |
616a6b93 | 874 | } |
7c49df64 | 875 | if (options.strict_host_key_checking == 1) { |
b0545fe6 | 876 | logit("%s", msg); |
f49bc4f7 | 877 | error("Exiting, you have requested strict checking."); |
878 | goto fail; | |
7c49df64 | 879 | } else if (options.strict_host_key_checking == 2) { |
616a6b93 | 880 | strlcat(msg, "\nAre you sure you want " |
881 | "to continue connecting (yes/no)? ", sizeof(msg)); | |
882 | if (!confirm(msg)) | |
f49bc4f7 | 883 | goto fail; |
616a6b93 | 884 | } else { |
b0545fe6 | 885 | logit("%s", msg); |
7c49df64 | 886 | } |
887 | } | |
888 | ||
0b6fbf03 | 889 | xfree(ip); |
d4530052 | 890 | xfree(host); |
f49bc4f7 | 891 | return 0; |
892 | ||
893 | fail: | |
894 | xfree(ip); | |
d4530052 | 895 | xfree(host); |
f49bc4f7 | 896 | return -1; |
897 | } | |
898 | ||
21289cd0 | 899 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
f49bc4f7 | 900 | int |
901 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) | |
902 | { | |
903 | struct stat st; | |
0161a13d | 904 | int flags = 0; |
f49bc4f7 | 905 | |
0161a13d | 906 | if (options.verify_host_key_dns && |
907 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { | |
908 | ||
909 | if (flags & DNS_VERIFY_FOUND) { | |
910 | ||
911 | if (options.verify_host_key_dns == 1 && | |
912 | flags & DNS_VERIFY_MATCH && | |
913 | flags & DNS_VERIFY_SECURE) | |
914 | return 0; | |
915 | ||
916 | if (flags & DNS_VERIFY_MATCH) { | |
917 | matching_host_key_dns = 1; | |
918 | } else { | |
919 | warn_changed_key(host_key); | |
920 | error("Update the SSHFP RR in DNS with the new " | |
921 | "host key to get rid of this message."); | |
922 | } | |
21289cd0 | 923 | } |
924 | } | |
21289cd0 | 925 | |
f49bc4f7 | 926 | /* return ok if the key can be found in an old keyfile */ |
927 | if (stat(options.system_hostfile2, &st) == 0 || | |
928 | stat(options.user_hostfile2, &st) == 0) { | |
331c3884 | 929 | if (check_host_key(host, hostaddr, options.port, host_key, |
930 | RDONLY, options.user_hostfile2, | |
931 | options.system_hostfile2) == 0) | |
f49bc4f7 | 932 | return 0; |
933 | } | |
331c3884 | 934 | return check_host_key(host, hostaddr, options.port, host_key, |
935 | RDRW, options.user_hostfile, options.system_hostfile); | |
95f1eccc | 936 | } |
937 | ||
8ce64345 | 938 | /* |
a306f2dd | 939 | * Starts a dialog with the server, and authenticates the current user on the |
940 | * server. This does not need any extra privileges. The basic connection | |
941 | * to the server must already have been established before this is called. | |
942 | * If login fails, this function prints an error and never returns. | |
943 | * This function does not require super-user privileges. | |
8ce64345 | 944 | */ |
945 | void | |
39c00dc2 | 946 | ssh_login(Sensitive *sensitive, const char *orighost, |
63bd8c36 | 947 | struct sockaddr *hostaddr, struct passwd *pw) |
8ce64345 | 948 | { |
a306f2dd | 949 | char *host, *cp; |
8ce64345 | 950 | char *server_user, *local_user; |
8ce64345 | 951 | |
8ce64345 | 952 | local_user = xstrdup(pw->pw_name); |
953 | server_user = options.user ? options.user : local_user; | |
954 | ||
7b2ea3a1 | 955 | /* Convert the user-supplied hostname into all lowercase. */ |
956 | host = xstrdup(orighost); | |
957 | for (cp = host; *cp; cp++) | |
958 | if (isupper(*cp)) | |
9555d258 | 959 | *cp = (char)tolower(*cp); |
7b2ea3a1 | 960 | |
961 | /* Exchange protocol version identification strings with the server. */ | |
962 | ssh_exchange_identification(); | |
963 | ||
964 | /* Put the connection into non-blocking mode. */ | |
965 | packet_set_nonblocking(); | |
966 | ||
7b2ea3a1 | 967 | /* key exchange */ |
7b2ea3a1 | 968 | /* authenticate user */ |
8ce64345 | 969 | if (compat20) { |
970 | ssh_kex2(host, hostaddr); | |
39c00dc2 | 971 | ssh_userauth2(local_user, server_user, host, sensitive); |
8ce64345 | 972 | } else { |
8ce64345 | 973 | ssh_kex(host, hostaddr); |
39c00dc2 | 974 | ssh_userauth1(local_user, server_user, host, sensitive); |
8ce64345 | 975 | } |
2b8dc5e3 | 976 | xfree(local_user); |
7b2ea3a1 | 977 | } |
0ae4fe1d | 978 | |
979 | void | |
980 | ssh_put_password(char *password) | |
981 | { | |
982 | int size; | |
983 | char *padded; | |
984 | ||
99c415db | 985 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
449c5ba5 | 986 | packet_put_cstring(password); |
99c415db | 987 | return; |
988 | } | |
0ae4fe1d | 989 | size = roundup(strlen(password) + 1, 32); |
52e3daed | 990 | padded = xcalloc(1, size); |
0ae4fe1d | 991 | strlcpy(padded, password, size); |
992 | packet_put_string(padded, size); | |
993 | memset(padded, 0, size); | |
994 | xfree(padded); | |
995 | } | |
8a48a7ef | 996 | |
997 | static int | |
998 | show_key_from_file(const char *file, const char *host, int keytype) | |
999 | { | |
1000 | Key *found; | |
1001 | char *fp; | |
1002 | int line, ret; | |
1003 | ||
1004 | found = key_new(keytype); | |
1005 | if ((ret = lookup_key_in_hostfile_by_type(file, host, | |
1006 | keytype, found, &line))) { | |
1007 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); | |
bbe88b6d | 1008 | logit("WARNING: %s key found for host %s\n" |
567a05bf | 1009 | "in %s:%d\n" |
8a48a7ef | 1010 | "%s key fingerprint %s.", |
1011 | key_type(found), host, file, line, | |
1012 | key_type(found), fp); | |
1013 | xfree(fp); | |
1014 | } | |
1015 | key_free(found); | |
1016 | return (ret); | |
1017 | } | |
1018 | ||
1019 | /* print all known host keys for a given host, but skip keys of given type */ | |
1020 | static int | |
1021 | show_other_keys(const char *host, Key *key) | |
1022 | { | |
1023 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; | |
1024 | int i, found = 0; | |
1025 | ||
1026 | for (i = 0; type[i] != -1; i++) { | |
1027 | if (type[i] == key->type) | |
1028 | continue; | |
1029 | if (type[i] != KEY_RSA1 && | |
1030 | show_key_from_file(options.user_hostfile2, host, type[i])) { | |
1031 | found = 1; | |
1032 | continue; | |
1033 | } | |
1034 | if (type[i] != KEY_RSA1 && | |
1035 | show_key_from_file(options.system_hostfile2, host, type[i])) { | |
1036 | found = 1; | |
1037 | continue; | |
1038 | } | |
1039 | if (show_key_from_file(options.user_hostfile, host, type[i])) { | |
1040 | found = 1; | |
1041 | continue; | |
1042 | } | |
1043 | if (show_key_from_file(options.system_hostfile, host, type[i])) { | |
1044 | found = 1; | |
1045 | continue; | |
1046 | } | |
1047 | debug2("no key of type %d for host %s", type[i], host); | |
1048 | } | |
1049 | return (found); | |
1050 | } | |
1a1bc5d5 | 1051 | |
1052 | static void | |
1053 | warn_changed_key(Key *host_key) | |
1054 | { | |
1055 | char *fp; | |
f5da7f70 | 1056 | const char *type = key_type(host_key); |
1a1bc5d5 | 1057 | |
1058 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); | |
1059 | ||
1060 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1061 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); | |
1062 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1063 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); | |
1064 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); | |
1065 | error("It is also possible that the %s host key has just been changed.", type); | |
1066 | error("The fingerprint for the %s key sent by the remote host is\n%s.", | |
1067 | type, fp); | |
1068 | error("Please contact your system administrator."); | |
1069 | ||
1070 | xfree(fp); | |
1a1bc5d5 | 1071 | } |
d20f3c9e | 1072 | |
1073 | /* | |
1074 | * Execute a local command | |
1075 | */ | |
1076 | int | |
1077 | ssh_local_cmd(const char *args) | |
1078 | { | |
1079 | char *shell; | |
1080 | pid_t pid; | |
1081 | int status; | |
1082 | ||
1083 | if (!options.permit_local_command || | |
1084 | args == NULL || !*args) | |
1085 | return (1); | |
1086 | ||
1087 | if ((shell = getenv("SHELL")) == NULL) | |
1088 | shell = _PATH_BSHELL; | |
1089 | ||
1090 | pid = fork(); | |
1091 | if (pid == 0) { | |
1092 | debug3("Executing %s -c \"%s\"", shell, args); | |
1093 | execl(shell, shell, "-c", args, (char *)NULL); | |
1094 | error("Couldn't execute %s -c \"%s\": %s", | |
1095 | shell, args, strerror(errno)); | |
1096 | _exit(1); | |
1097 | } else if (pid == -1) | |
1098 | fatal("fork failed: %.100s", strerror(errno)); | |
1099 | while (waitpid(pid, &status, 0) == -1) | |
1100 | if (errno != EINTR) | |
1101 | fatal("Couldn't wait for child: %s", strerror(errno)); | |
1102 | ||
1103 | if (!WIFEXITED(status)) | |
1104 | return (1); | |
1105 | ||
1106 | return (WEXITSTATUS(status)); | |
1107 | } |