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Commit | Line | Data |
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8efc0c15 | 1 | /* |
5260325f | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5260325f | 5 | * Code to connect to a remote host, and to perform the client side of the |
6 | * login (authentication) dialog. | |
bcbf86ec | 7 | * |
8 | * As far as I am concerned, the code I have written for this software | |
9 | * can be used freely for any purpose. Any derived versions of this | |
10 | * software must be clearly marked as such, and if the derived work is | |
11 | * incompatible with the protocol description in the RFC file, it must be | |
12 | * called by a name other than "ssh" or "Secure Shell". | |
5260325f | 13 | */ |
8efc0c15 | 14 | |
15 | #include "includes.h" | |
2daf1db1 | 16 | RCSID("$OpenBSD: sshconnect.c,v 1.156 2004/01/25 03:49:09 djm Exp $"); |
8efc0c15 | 17 | |
8ce64345 | 18 | #include <openssl/bn.h> |
a306f2dd | 19 | |
42f11eb2 | 20 | #include "ssh.h" |
8efc0c15 | 21 | #include "xmalloc.h" |
22 | #include "rsa.h" | |
8ce64345 | 23 | #include "buffer.h" |
8efc0c15 | 24 | #include "packet.h" |
8efc0c15 | 25 | #include "uidswap.h" |
26 | #include "compat.h" | |
4fe2af09 | 27 | #include "key.h" |
a306f2dd | 28 | #include "sshconnect.h" |
4fe2af09 | 29 | #include "hostfile.h" |
42f11eb2 | 30 | #include "log.h" |
31 | #include "readconf.h" | |
32 | #include "atomicio.h" | |
33 | #include "misc.h" | |
616a6b93 | 34 | #include "readpass.h" |
8efc0c15 | 35 | |
21289cd0 | 36 | #include "dns.h" |
21289cd0 | 37 | |
a306f2dd | 38 | char *client_version_string = NULL; |
39 | char *server_version_string = NULL; | |
8ce64345 | 40 | |
0161a13d | 41 | int matching_host_key_dns = 0; |
1432b5c4 | 42 | |
3fb156df | 43 | /* import */ |
57112b5a | 44 | extern Options options; |
48e671d5 | 45 | extern char *__progname; |
3fb156df | 46 | extern uid_t original_real_uid; |
47 | extern uid_t original_effective_uid; | |
6939bbd4 | 48 | extern pid_t proxy_command_pid; |
57112b5a | 49 | |
a704dd54 | 50 | #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */ |
51 | #define INET6_ADDRSTRLEN 46 | |
52 | #endif | |
53 | ||
8a48a7ef | 54 | static int show_other_keys(const char *, Key *); |
1a1bc5d5 | 55 | static void warn_changed_key(Key *); |
8a48a7ef | 56 | |
5260325f | 57 | /* |
58 | * Connect to the given ssh server using a proxy command. | |
59 | */ | |
396c147e | 60 | static int |
3fb156df | 61 | ssh_proxy_connect(const char *host, u_short port, const char *proxy_command) |
8efc0c15 | 62 | { |
5260325f | 63 | Buffer command; |
64 | const char *cp; | |
65 | char *command_string; | |
66 | int pin[2], pout[2]; | |
9da5c3c9 | 67 | pid_t pid; |
48e671d5 | 68 | char strport[NI_MAXSERV]; |
5260325f | 69 | |
70 | /* Convert the port number into a string. */ | |
48e671d5 | 71 | snprintf(strport, sizeof strport, "%hu", port); |
5260325f | 72 | |
6939bbd4 | 73 | /* |
74 | * Build the final command string in the buffer by making the | |
75 | * appropriate substitutions to the given proxy command. | |
76 | * | |
aff51935 | 77 | * Use "exec" to avoid "sh -c" processes on some platforms |
6939bbd4 | 78 | * (e.g. Solaris) |
79 | */ | |
5260325f | 80 | buffer_init(&command); |
6939bbd4 | 81 | buffer_append(&command, "exec ", 5); |
82 | ||
5260325f | 83 | for (cp = proxy_command; *cp; cp++) { |
84 | if (cp[0] == '%' && cp[1] == '%') { | |
85 | buffer_append(&command, "%", 1); | |
86 | cp++; | |
87 | continue; | |
88 | } | |
89 | if (cp[0] == '%' && cp[1] == 'h') { | |
90 | buffer_append(&command, host, strlen(host)); | |
91 | cp++; | |
92 | continue; | |
93 | } | |
94 | if (cp[0] == '%' && cp[1] == 'p') { | |
48e671d5 | 95 | buffer_append(&command, strport, strlen(strport)); |
5260325f | 96 | cp++; |
97 | continue; | |
98 | } | |
99 | buffer_append(&command, cp, 1); | |
8efc0c15 | 100 | } |
5260325f | 101 | buffer_append(&command, "\0", 1); |
102 | ||
103 | /* Get the final command string. */ | |
104 | command_string = buffer_ptr(&command); | |
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. */ | |
3fb156df | 118 | seteuid(original_real_uid); |
119 | setuid(original_real_uid); | |
5260325f | 120 | |
121 | /* Redirect stdin and stdout. */ | |
122 | close(pin[1]); | |
123 | if (pin[0] != 0) { | |
124 | if (dup2(pin[0], 0) < 0) | |
125 | perror("dup2 stdin"); | |
126 | close(pin[0]); | |
127 | } | |
128 | close(pout[0]); | |
129 | if (dup2(pout[1], 1) < 0) | |
130 | perror("dup2 stdout"); | |
131 | /* Cannot be 1 because pin allocated two descriptors. */ | |
132 | close(pout[1]); | |
133 | ||
134 | /* Stderr is left as it is so that error messages get | |
135 | printed on the user's terminal. */ | |
30228d7c | 136 | argv[0] = _PATH_BSHELL; |
5260325f | 137 | argv[1] = "-c"; |
138 | argv[2] = command_string; | |
139 | argv[3] = NULL; | |
140 | ||
141 | /* Execute the proxy command. Note that we gave up any | |
142 | extra privileges above. */ | |
328654d8 | 143 | execv(argv[0], argv); |
144 | perror(argv[0]); | |
5260325f | 145 | exit(1); |
8efc0c15 | 146 | } |
5260325f | 147 | /* Parent. */ |
148 | if (pid < 0) | |
149 | fatal("fork failed: %.100s", strerror(errno)); | |
6939bbd4 | 150 | else |
151 | proxy_command_pid = pid; /* save pid to clean up later */ | |
5260325f | 152 | |
153 | /* Close child side of the descriptors. */ | |
154 | close(pin[0]); | |
155 | close(pout[1]); | |
156 | ||
157 | /* Free the command name. */ | |
158 | buffer_free(&command); | |
159 | ||
160 | /* Set the connection file descriptors. */ | |
161 | packet_set_connection(pout[0], pin[1]); | |
8efc0c15 | 162 | |
ce773142 | 163 | /* Indicate OK return */ |
164 | return 0; | |
5260325f | 165 | } |
8efc0c15 | 166 | |
5260325f | 167 | /* |
168 | * Creates a (possibly privileged) socket for use as the ssh connection. | |
169 | */ | |
396c147e | 170 | static int |
3e131a6d | 171 | ssh_create_socket(int privileged, struct addrinfo *ai) |
8efc0c15 | 172 | { |
3435f5a6 | 173 | int sock, gaierr; |
174 | struct addrinfo hints, *res; | |
5260325f | 175 | |
aa3378df | 176 | /* |
177 | * If we are running as root and want to connect to a privileged | |
178 | * port, bind our own socket to a privileged port. | |
179 | */ | |
5260325f | 180 | if (privileged) { |
181 | int p = IPPORT_RESERVED - 1; | |
3fb156df | 182 | PRIV_START; |
3e131a6d | 183 | sock = rresvport_af(&p, ai->ai_family); |
3fb156df | 184 | PRIV_END; |
5260325f | 185 | if (sock < 0) |
3e131a6d | 186 | error("rresvport: af=%d %.100s", ai->ai_family, |
187 | strerror(errno)); | |
c8d54615 | 188 | else |
189 | debug("Allocated local port %d.", p); | |
3435f5a6 | 190 | return sock; |
191 | } | |
3e131a6d | 192 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3435f5a6 | 193 | if (sock < 0) |
194 | error("socket: %.100s", strerror(errno)); | |
3435f5a6 | 195 | |
196 | /* Bind the socket to an alternative local IP address */ | |
197 | if (options.bind_address == NULL) | |
198 | return sock; | |
199 | ||
200 | memset(&hints, 0, sizeof(hints)); | |
3e131a6d | 201 | hints.ai_family = ai->ai_family; |
202 | hints.ai_socktype = ai->ai_socktype; | |
203 | hints.ai_protocol = ai->ai_protocol; | |
3435f5a6 | 204 | hints.ai_flags = AI_PASSIVE; |
205 | gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); | |
206 | if (gaierr) { | |
207 | error("getaddrinfo: %s: %s", options.bind_address, | |
208 | gai_strerror(gaierr)); | |
209 | close(sock); | |
210 | return -1; | |
211 | } | |
212 | if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { | |
213 | error("bind: %s: %s", options.bind_address, strerror(errno)); | |
214 | close(sock); | |
215 | freeaddrinfo(res); | |
216 | return -1; | |
5260325f | 217 | } |
3435f5a6 | 218 | freeaddrinfo(res); |
5260325f | 219 | return sock; |
8efc0c15 | 220 | } |
221 | ||
09ab3296 | 222 | static int |
223 | timeout_connect(int sockfd, const struct sockaddr *serv_addr, | |
224 | socklen_t addrlen, int timeout) | |
225 | { | |
226 | fd_set *fdset; | |
227 | struct timeval tv; | |
228 | socklen_t optlen; | |
da54f5be | 229 | int fdsetsz, optval, rc, result = -1; |
09ab3296 | 230 | |
231 | if (timeout <= 0) | |
232 | return (connect(sockfd, serv_addr, addrlen)); | |
233 | ||
2daf1db1 | 234 | set_nonblock(sockfd); |
09ab3296 | 235 | rc = connect(sockfd, serv_addr, addrlen); |
2daf1db1 | 236 | if (rc == 0) { |
237 | unset_nonblock(sockfd); | |
09ab3296 | 238 | return (0); |
2daf1db1 | 239 | } |
09ab3296 | 240 | if (errno != EINPROGRESS) |
241 | return (-1); | |
242 | ||
243 | fdsetsz = howmany(sockfd + 1, NFDBITS) * sizeof(fd_mask); | |
244 | fdset = (fd_set *)xmalloc(fdsetsz); | |
245 | ||
7caca6d4 | 246 | memset(fdset, 0, fdsetsz); |
09ab3296 | 247 | FD_SET(sockfd, fdset); |
248 | tv.tv_sec = timeout; | |
249 | tv.tv_usec = 0; | |
250 | ||
251 | for(;;) { | |
252 | rc = select(sockfd + 1, NULL, fdset, NULL, &tv); | |
253 | if (rc != -1 || errno != EINTR) | |
254 | break; | |
255 | } | |
256 | ||
257 | switch(rc) { | |
258 | case 0: | |
259 | /* Timed out */ | |
260 | errno = ETIMEDOUT; | |
da54f5be | 261 | break; |
09ab3296 | 262 | case -1: |
263 | /* Select error */ | |
aff51935 | 264 | debug("select: %s", strerror(errno)); |
da54f5be | 265 | break; |
09ab3296 | 266 | case 1: |
267 | /* Completed or failed */ | |
268 | optval = 0; | |
269 | optlen = sizeof(optval); | |
aff51935 | 270 | if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, |
ce26c02a | 271 | &optlen) == -1) { |
aff51935 | 272 | debug("getsockopt: %s", strerror(errno)); |
da54f5be | 273 | break; |
ce26c02a | 274 | } |
09ab3296 | 275 | if (optval != 0) { |
276 | errno = optval; | |
da54f5be | 277 | break; |
09ab3296 | 278 | } |
da54f5be | 279 | result = 0; |
2daf1db1 | 280 | unset_nonblock(sockfd); |
09ab3296 | 281 | break; |
282 | default: | |
283 | /* Should not occur */ | |
284 | fatal("Bogus return (%d) from select()", rc); | |
285 | } | |
286 | ||
da54f5be | 287 | xfree(fdset); |
288 | return (result); | |
09ab3296 | 289 | } |
290 | ||
5260325f | 291 | /* |
48e671d5 | 292 | * Opens a TCP/IP connection to the remote server on the given host. |
293 | * The address of the remote host will be returned in hostaddr. | |
3fb156df | 294 | * If port is 0, the default port will be used. If needpriv is true, |
5260325f | 295 | * a privileged port will be allocated to make the connection. |
3fb156df | 296 | * This requires super-user privileges if needpriv is true. |
5260325f | 297 | * Connection_attempts specifies the maximum number of tries (one per |
298 | * second). If proxy_command is non-NULL, it specifies the command (with %h | |
299 | * and %p substituted for host and port, respectively) to use to contact | |
300 | * the daemon. | |
ce773142 | 301 | * Return values: |
302 | * 0 for OK | |
303 | * ECONNREFUSED if we got a "Connection Refused" by the peer on any address | |
304 | * ECONNABORTED if we failed without a "Connection refused" | |
305 | * Suitable error messages for the connection failure will already have been | |
306 | * printed. | |
5260325f | 307 | */ |
308 | int | |
48e671d5 | 309 | ssh_connect(const char *host, struct sockaddr_storage * hostaddr, |
dab89049 | 310 | u_short port, int family, int connection_attempts, |
3fb156df | 311 | int needpriv, const char *proxy_command) |
8efc0c15 | 312 | { |
b5c334cc | 313 | int gaierr; |
314 | int on = 1; | |
48e671d5 | 315 | int sock = -1, attempt; |
48e671d5 | 316 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
b5c334cc | 317 | struct addrinfo hints, *ai, *aitop; |
b5c334cc | 318 | struct servent *sp; |
ce773142 | 319 | /* |
320 | * Did we get only other errors than "Connection refused" (which | |
321 | * should block fallback to rsh and similar), or did we get at least | |
322 | * one "Connection refused"? | |
323 | */ | |
324 | int full_failure = 1; | |
5260325f | 325 | |
a77673cc | 326 | debug2("ssh_connect: needpriv %d", needpriv); |
5260325f | 327 | |
328 | /* Get default port if port has not been set. */ | |
329 | if (port == 0) { | |
330 | sp = getservbyname(SSH_SERVICE_NAME, "tcp"); | |
331 | if (sp) | |
332 | port = ntohs(sp->s_port); | |
333 | else | |
334 | port = SSH_DEFAULT_PORT; | |
8efc0c15 | 335 | } |
5260325f | 336 | /* If a proxy command is given, connect using it. */ |
337 | if (proxy_command != NULL) | |
3fb156df | 338 | return ssh_proxy_connect(host, port, proxy_command); |
5260325f | 339 | |
340 | /* No proxy command. */ | |
341 | ||
48e671d5 | 342 | memset(&hints, 0, sizeof(hints)); |
dab89049 | 343 | hints.ai_family = family; |
48e671d5 | 344 | hints.ai_socktype = SOCK_STREAM; |
d6133f43 | 345 | snprintf(strport, sizeof strport, "%u", port); |
48e671d5 | 346 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) |
347 | fatal("%s: %.100s: %s", __progname, host, | |
348 | gai_strerror(gaierr)); | |
5260325f | 349 | |
95f1eccc | 350 | /* |
351 | * Try to connect several times. On some machines, the first time | |
352 | * will sometimes fail. In general socket code appears to behave | |
353 | * quite magically on many machines. | |
ce773142 | 354 | */ |
355 | for (attempt = 0; ;) { | |
5260325f | 356 | if (attempt > 0) |
357 | debug("Trying again..."); | |
358 | ||
48e671d5 | 359 | /* Loop through addresses for this host, and try each one in |
6ae2364d | 360 | sequence until the connection succeeds. */ |
48e671d5 | 361 | for (ai = aitop; ai; ai = ai->ai_next) { |
362 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
363 | continue; | |
364 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
365 | ntop, sizeof(ntop), strport, sizeof(strport), | |
366 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
367 | error("ssh_connect: getnameinfo failed"); | |
368 | continue; | |
369 | } | |
370 | debug("Connecting to %.200s [%.100s] port %s.", | |
371 | host, ntop, strport); | |
372 | ||
373 | /* Create a socket for connecting. */ | |
3e131a6d | 374 | sock = ssh_create_socket(needpriv, ai); |
48e671d5 | 375 | if (sock < 0) |
ce773142 | 376 | /* Any error is already output */ |
48e671d5 | 377 | continue; |
378 | ||
09ab3296 | 379 | if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen, |
380 | options.connection_timeout) >= 0) { | |
48e671d5 | 381 | /* Successful connection. */ |
cd332296 | 382 | memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen); |
5260325f | 383 | break; |
48e671d5 | 384 | } else { |
ce773142 | 385 | if (errno == ECONNREFUSED) |
386 | full_failure = 0; | |
c750d869 | 387 | debug("connect to address %s port %s: %s", |
388 | ntop, strport, strerror(errno)); | |
aa3378df | 389 | /* |
390 | * Close the failed socket; there appear to | |
391 | * be some problems when reusing a socket for | |
392 | * which connect() has already returned an | |
393 | * error. | |
394 | */ | |
5260325f | 395 | close(sock); |
396 | } | |
8efc0c15 | 397 | } |
48e671d5 | 398 | if (ai) |
399 | break; /* Successful connection. */ | |
8efc0c15 | 400 | |
ce773142 | 401 | attempt++; |
402 | if (attempt >= connection_attempts) | |
403 | break; | |
5260325f | 404 | /* Sleep a moment before retrying. */ |
405 | sleep(1); | |
406 | } | |
48e671d5 | 407 | |
408 | freeaddrinfo(aitop); | |
409 | ||
5260325f | 410 | /* Return failure if we didn't get a successful connection. */ |
9bd68577 | 411 | if (attempt >= connection_attempts) { |
bbe88b6d | 412 | logit("ssh: connect to host %s port %s: %s", |
9bd68577 | 413 | host, strport, strerror(errno)); |
ce773142 | 414 | return full_failure ? ECONNABORTED : ECONNREFUSED; |
9bd68577 | 415 | } |
8efc0c15 | 416 | |
5260325f | 417 | debug("Connection established."); |
8efc0c15 | 418 | |
fd573618 | 419 | /* Set SO_KEEPALIVE if requested. */ |
420 | if (options.tcp_keep_alive && | |
b5c334cc | 421 | setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, |
422 | sizeof(on)) < 0) | |
423 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
8efc0c15 | 424 | |
5260325f | 425 | /* Set the connection. */ |
426 | packet_set_connection(sock, sock); | |
8efc0c15 | 427 | |
ce773142 | 428 | return 0; |
8efc0c15 | 429 | } |
430 | ||
5260325f | 431 | /* |
432 | * Waits for the server identification string, and sends our own | |
433 | * identification string. | |
434 | */ | |
396c147e | 435 | static void |
5ca51e19 | 436 | ssh_exchange_identification(void) |
8efc0c15 | 437 | { |
5260325f | 438 | char buf[256], remote_version[256]; /* must be same size! */ |
a8be9f80 | 439 | int remote_major, remote_minor, i, mismatch; |
5260325f | 440 | int connection_in = packet_get_connection_in(); |
441 | int connection_out = packet_get_connection_out(); | |
2b87da3b | 442 | int minor1 = PROTOCOL_MINOR_1; |
5260325f | 443 | |
444 | /* Read other side\'s version identification. */ | |
38c295d6 | 445 | for (;;) { |
446 | for (i = 0; i < sizeof(buf) - 1; i++) { | |
447 | int len = atomicio(read, connection_in, &buf[i], 1); | |
448 | if (len < 0) | |
449 | fatal("ssh_exchange_identification: read: %.100s", strerror(errno)); | |
450 | if (len != 1) | |
451 | fatal("ssh_exchange_identification: Connection closed by remote host"); | |
452 | if (buf[i] == '\r') { | |
453 | buf[i] = '\n'; | |
454 | buf[i + 1] = 0; | |
455 | continue; /**XXX wait for \n */ | |
456 | } | |
457 | if (buf[i] == '\n') { | |
458 | buf[i + 1] = 0; | |
459 | break; | |
460 | } | |
5260325f | 461 | } |
38c295d6 | 462 | buf[sizeof(buf) - 1] = 0; |
463 | if (strncmp(buf, "SSH-", 4) == 0) | |
5260325f | 464 | break; |
38c295d6 | 465 | debug("ssh_exchange_identification: %s", buf); |
8efc0c15 | 466 | } |
8ce64345 | 467 | server_version_string = xstrdup(buf); |
5260325f | 468 | |
aa3378df | 469 | /* |
470 | * Check that the versions match. In future this might accept | |
471 | * several versions and set appropriate flags to handle them. | |
472 | */ | |
8ce64345 | 473 | if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n", |
474 | &remote_major, &remote_minor, remote_version) != 3) | |
5260325f | 475 | fatal("Bad remote protocol version identification: '%.100s'", buf); |
476 | debug("Remote protocol version %d.%d, remote software version %.100s", | |
184eed6a | 477 | remote_major, remote_minor, remote_version); |
5260325f | 478 | |
8ce64345 | 479 | compat_datafellows(remote_version); |
a8be9f80 | 480 | mismatch = 0; |
481 | ||
6aacefa7 | 482 | switch (remote_major) { |
a8be9f80 | 483 | case 1: |
484 | if (remote_minor == 99 && | |
485 | (options.protocol & SSH_PROTO_2) && | |
486 | !(options.protocol & SSH_PROTO_1_PREFERRED)) { | |
487 | enable_compat20(); | |
488 | break; | |
5260325f | 489 | } |
a8be9f80 | 490 | if (!(options.protocol & SSH_PROTO_1)) { |
491 | mismatch = 1; | |
492 | break; | |
493 | } | |
494 | if (remote_minor < 3) { | |
495 | fatal("Remote machine has too old SSH software version."); | |
fa08c86b | 496 | } else if (remote_minor == 3 || remote_minor == 4) { |
a8be9f80 | 497 | /* We speak 1.3, too. */ |
498 | enable_compat13(); | |
fa08c86b | 499 | minor1 = 3; |
a8be9f80 | 500 | if (options.forward_agent) { |
bbe88b6d | 501 | logit("Agent forwarding disabled for protocol 1.3"); |
a8be9f80 | 502 | options.forward_agent = 0; |
503 | } | |
504 | } | |
505 | break; | |
506 | case 2: | |
507 | if (options.protocol & SSH_PROTO_2) { | |
508 | enable_compat20(); | |
509 | break; | |
510 | } | |
511 | /* FALLTHROUGH */ | |
6ae2364d | 512 | default: |
a8be9f80 | 513 | mismatch = 1; |
514 | break; | |
8efc0c15 | 515 | } |
a8be9f80 | 516 | if (mismatch) |
5260325f | 517 | fatal("Protocol major versions differ: %d vs. %d", |
a8be9f80 | 518 | (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
519 | remote_major); | |
5260325f | 520 | /* Send our own protocol version identification. */ |
521 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", | |
a8be9f80 | 522 | compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, |
fa08c86b | 523 | compat20 ? PROTOCOL_MINOR_2 : minor1, |
8ce64345 | 524 | SSH_VERSION); |
dc54438a | 525 | if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf)) |
5260325f | 526 | fatal("write: %.100s", strerror(errno)); |
8ce64345 | 527 | client_version_string = xstrdup(buf); |
528 | chop(client_version_string); | |
529 | chop(server_version_string); | |
530 | debug("Local version string %.100s", client_version_string); | |
8efc0c15 | 531 | } |
532 | ||
f21032a6 | 533 | /* defaults to 'no' */ |
396c147e | 534 | static int |
a2c92c4a | 535 | confirm(const char *prompt) |
8efc0c15 | 536 | { |
616a6b93 | 537 | const char *msg, *again = "Please type 'yes' or 'no': "; |
538 | char *p; | |
539 | int ret = -1; | |
5260325f | 540 | |
f21032a6 | 541 | if (options.batch_mode) |
542 | return 0; | |
616a6b93 | 543 | for (msg = prompt;;msg = again) { |
544 | p = read_passphrase(msg, RP_ECHO); | |
545 | if (p == NULL || | |
546 | (p[0] == '\0') || (p[0] == '\n') || | |
547 | strncasecmp(p, "no", 2) == 0) | |
548 | ret = 0; | |
f11fe301 | 549 | if (p && strncasecmp(p, "yes", 3) == 0) |
616a6b93 | 550 | ret = 1; |
551 | if (p) | |
552 | xfree(p); | |
553 | if (ret != -1) | |
554 | return ret; | |
8efc0c15 | 555 | } |
8efc0c15 | 556 | } |
557 | ||
5260325f | 558 | /* |
f49bc4f7 | 559 | * check whether the supplied host key is valid, return -1 if the key |
560 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. | |
5260325f | 561 | */ |
396c147e | 562 | static int |
a306f2dd | 563 | check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, |
f49bc4f7 | 564 | int readonly, const char *user_hostfile, const char *system_hostfile) |
8efc0c15 | 565 | { |
4fe2af09 | 566 | Key *file_key; |
b6c7b7b7 | 567 | const char *type = key_type(host_key); |
95f1eccc | 568 | char *ip = NULL; |
22138a36 | 569 | char hostline[1000], *hostp, *fp; |
5260325f | 570 | HostStatus host_status; |
571 | HostStatus ip_status; | |
48e671d5 | 572 | int local = 0, host_ip_differ = 0; |
20af321f | 573 | int salen; |
48e671d5 | 574 | char ntop[NI_MAXHOST]; |
616a6b93 | 575 | char msg[1024]; |
1432b5c4 | 576 | int len, host_line, ip_line; |
1e3b8b07 | 577 | const char *host_file = NULL, *ip_file = NULL; |
48e671d5 | 578 | |
579 | /* | |
580 | * Force accepting of the host key for loopback/localhost. The | |
581 | * problem is that if the home directory is NFS-mounted to multiple | |
582 | * machines, localhost will refer to a different machine in each of | |
583 | * them, and the user will get bogus HOST_CHANGED warnings. This | |
584 | * essentially disables host authentication for localhost; however, | |
585 | * this is probably not a real problem. | |
586 | */ | |
a306f2dd | 587 | /** hostaddr == 0! */ |
48e671d5 | 588 | switch (hostaddr->sa_family) { |
589 | case AF_INET: | |
f49bc4f7 | 590 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
20a11d35 | 591 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; |
20af321f | 592 | salen = sizeof(struct sockaddr_in); |
48e671d5 | 593 | break; |
594 | case AF_INET6: | |
f49bc4f7 | 595 | local = IN6_IS_ADDR_LOOPBACK( |
596 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | |
20af321f | 597 | salen = sizeof(struct sockaddr_in6); |
48e671d5 | 598 | break; |
599 | default: | |
600 | local = 0; | |
20af321f | 601 | salen = sizeof(struct sockaddr_storage); |
48e671d5 | 602 | break; |
603 | } | |
8bbc048a | 604 | if (options.no_host_authentication_for_localhost == 1 && local && |
605 | options.host_key_alias == NULL) { | |
7c49df64 | 606 | debug("Forcing accepting of host key for " |
607 | "loopback/localhost."); | |
f49bc4f7 | 608 | return 0; |
48e671d5 | 609 | } |
5260325f | 610 | |
57112b5a | 611 | /* |
7c49df64 | 612 | * We don't have the remote ip-address for connections |
613 | * using a proxy command | |
614 | */ | |
615 | if (options.proxy_command == NULL) { | |
616 | if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop), | |
617 | NULL, 0, NI_NUMERICHOST) != 0) | |
618 | fatal("check_host_key: getnameinfo failed"); | |
619 | ip = xstrdup(ntop); | |
620 | } else { | |
621 | ip = xstrdup("<no hostip for proxy command>"); | |
622 | } | |
623 | /* | |
624 | * Turn off check_host_ip if the connection is to localhost, via proxy | |
625 | * command or if we don't have a hostname to compare with | |
57112b5a | 626 | */ |
7c49df64 | 627 | if (options.check_host_ip && |
628 | (local || strcmp(host, ip) == 0 || options.proxy_command != NULL)) | |
57112b5a | 629 | options.check_host_ip = 0; |
630 | ||
8abcdba4 | 631 | /* |
7c49df64 | 632 | * Allow the user to record the key under a different name. This is |
8abcdba4 | 633 | * useful for ssh tunneling over forwarded connections or if you run |
7c49df64 | 634 | * multiple sshd's on different ports on the same machine. |
8abcdba4 | 635 | */ |
636 | if (options.host_key_alias != NULL) { | |
637 | host = options.host_key_alias; | |
638 | debug("using hostkeyalias: %s", host); | |
639 | } | |
640 | ||
95f1eccc | 641 | /* |
642 | * Store the host key from the known host file in here so that we can | |
643 | * compare it with the key for the IP address. | |
644 | */ | |
4fe2af09 | 645 | file_key = key_new(host_key->type); |
5260325f | 646 | |
aa3378df | 647 | /* |
648 | * Check if the host key is present in the user\'s list of known | |
649 | * hosts or in the systemwide list. | |
650 | */ | |
1e3b8b07 | 651 | host_file = user_hostfile; |
f49bc4f7 | 652 | host_status = check_host_in_hostfile(host_file, host, host_key, |
184eed6a | 653 | file_key, &host_line); |
1e3b8b07 | 654 | if (host_status == HOST_NEW) { |
655 | host_file = system_hostfile; | |
f49bc4f7 | 656 | host_status = check_host_in_hostfile(host_file, host, host_key, |
657 | file_key, &host_line); | |
1e3b8b07 | 658 | } |
aa3378df | 659 | /* |
660 | * Also perform check for the ip address, skip the check if we are | |
661 | * localhost or the hostname was an ip address to begin with | |
662 | */ | |
7c49df64 | 663 | if (options.check_host_ip) { |
4fe2af09 | 664 | Key *ip_key = key_new(host_key->type); |
5260325f | 665 | |
1e3b8b07 | 666 | ip_file = user_hostfile; |
f49bc4f7 | 667 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
668 | ip_key, &ip_line); | |
1e3b8b07 | 669 | if (ip_status == HOST_NEW) { |
670 | ip_file = system_hostfile; | |
f49bc4f7 | 671 | ip_status = check_host_in_hostfile(ip_file, ip, |
672 | host_key, ip_key, &ip_line); | |
1e3b8b07 | 673 | } |
5260325f | 674 | if (host_status == HOST_CHANGED && |
4fe2af09 | 675 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
5260325f | 676 | host_ip_differ = 1; |
677 | ||
4fe2af09 | 678 | key_free(ip_key); |
5260325f | 679 | } else |
680 | ip_status = host_status; | |
681 | ||
4fe2af09 | 682 | key_free(file_key); |
5260325f | 683 | |
684 | switch (host_status) { | |
685 | case HOST_OK: | |
686 | /* The host is known and the key matches. */ | |
1d1ffb87 | 687 | debug("Host '%.200s' is known and matches the %s host key.", |
688 | host, type); | |
1e3b8b07 | 689 | debug("Found key in %s:%d", host_file, host_line); |
7c49df64 | 690 | if (options.check_host_ip && ip_status == HOST_NEW) { |
f49bc4f7 | 691 | if (readonly) |
bbe88b6d | 692 | logit("%s host key for IP address " |
f49bc4f7 | 693 | "'%.128s' not in list of known hosts.", |
7c49df64 | 694 | type, ip); |
f49bc4f7 | 695 | else if (!add_host_to_hostfile(user_hostfile, ip, |
184eed6a | 696 | host_key)) |
bbe88b6d | 697 | logit("Failed to add the %s host key for IP " |
f49bc4f7 | 698 | "address '%.128s' to the list of known " |
699 | "hosts (%.30s).", type, ip, user_hostfile); | |
700 | else | |
bbe88b6d | 701 | logit("Warning: Permanently added the %s host " |
f49bc4f7 | 702 | "key for IP address '%.128s' to the list " |
703 | "of known hosts.", type, ip); | |
5260325f | 704 | } |
705 | break; | |
706 | case HOST_NEW: | |
f49bc4f7 | 707 | if (readonly) |
708 | goto fail; | |
5260325f | 709 | /* The host is new. */ |
710 | if (options.strict_host_key_checking == 1) { | |
f49bc4f7 | 711 | /* |
712 | * User has requested strict host key checking. We | |
713 | * will not add the host key automatically. The only | |
714 | * alternative left is to abort. | |
715 | */ | |
716 | error("No %s host key is known for %.200s and you " | |
717 | "have requested strict checking.", type, host); | |
718 | goto fail; | |
5260325f | 719 | } else if (options.strict_host_key_checking == 2) { |
1432b5c4 | 720 | char msg1[1024], msg2[1024]; |
721 | ||
722 | if (show_other_keys(host, host_key)) | |
723 | snprintf(msg1, sizeof(msg1), | |
724 | "\nbut keys of different type are already" | |
725 | " known for this host."); | |
726 | else | |
727 | snprintf(msg1, sizeof(msg1), "."); | |
5260325f | 728 | /* The default */ |
22138a36 | 729 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
1432b5c4 | 730 | msg2[0] = '\0'; |
1432b5c4 | 731 | if (options.verify_host_key_dns) { |
0161a13d | 732 | if (matching_host_key_dns) |
1432b5c4 | 733 | snprintf(msg2, sizeof(msg2), |
734 | "Matching host key fingerprint" | |
735 | " found in DNS.\n"); | |
736 | else | |
737 | snprintf(msg2, sizeof(msg2), | |
738 | "No matching host key fingerprint" | |
739 | " found in DNS.\n"); | |
740 | } | |
616a6b93 | 741 | snprintf(msg, sizeof(msg), |
f49bc4f7 | 742 | "The authenticity of host '%.200s (%s)' can't be " |
8a48a7ef | 743 | "established%s\n" |
1432b5c4 | 744 | "%s key fingerprint is %s.\n%s" |
f49bc4f7 | 745 | "Are you sure you want to continue connecting " |
8a48a7ef | 746 | "(yes/no)? ", |
1432b5c4 | 747 | host, ip, msg1, type, fp, msg2); |
22138a36 | 748 | xfree(fp); |
616a6b93 | 749 | if (!confirm(msg)) |
f49bc4f7 | 750 | goto fail; |
5260325f | 751 | } |
7c49df64 | 752 | if (options.check_host_ip && ip_status == HOST_NEW) { |
5260325f | 753 | snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); |
754 | hostp = hostline; | |
755 | } else | |
756 | hostp = host; | |
757 | ||
f49bc4f7 | 758 | /* |
759 | * If not in strict mode, add the key automatically to the | |
760 | * local known_hosts file. | |
761 | */ | |
a306f2dd | 762 | if (!add_host_to_hostfile(user_hostfile, hostp, host_key)) |
bbe88b6d | 763 | logit("Failed to add the host to the list of known " |
f49bc4f7 | 764 | "hosts (%.500s).", user_hostfile); |
5260325f | 765 | else |
bbe88b6d | 766 | logit("Warning: Permanently added '%.200s' (%s) to the " |
f49bc4f7 | 767 | "list of known hosts.", hostp, type); |
5260325f | 768 | break; |
769 | case HOST_CHANGED: | |
770 | if (options.check_host_ip && host_ip_differ) { | |
771 | char *msg; | |
772 | if (ip_status == HOST_NEW) | |
773 | msg = "is unknown"; | |
774 | else if (ip_status == HOST_OK) | |
775 | msg = "is unchanged"; | |
776 | else | |
777 | msg = "has a different value"; | |
778 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
779 | error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @"); | |
780 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1d1ffb87 | 781 | error("The %s host key for %s has changed,", type, host); |
5260325f | 782 | error("and the key for the according IP address %s", ip); |
783 | error("%s. This could either mean that", msg); | |
784 | error("DNS SPOOFING is happening or the IP address for the host"); | |
1e3b8b07 | 785 | error("and its host key have changed at the same time."); |
7c49df64 | 786 | if (ip_status != HOST_NEW) |
1e3b8b07 | 787 | error("Offending key for IP in %s:%d", ip_file, ip_line); |
5260325f | 788 | } |
789 | /* The host key has changed. */ | |
1a1bc5d5 | 790 | warn_changed_key(host_key); |
5260325f | 791 | error("Add correct host key in %.100s to get rid of this message.", |
8abcdba4 | 792 | user_hostfile); |
1e3b8b07 | 793 | error("Offending key in %s:%d", host_file, host_line); |
5260325f | 794 | |
aa3378df | 795 | /* |
796 | * If strict host key checking is in use, the user will have | |
797 | * to edit the key manually and we can only abort. | |
798 | */ | |
f49bc4f7 | 799 | if (options.strict_host_key_checking) { |
800 | error("%s host key for %.200s has changed and you have " | |
801 | "requested strict checking.", type, host); | |
802 | goto fail; | |
803 | } | |
5260325f | 804 | |
aa3378df | 805 | /* |
806 | * If strict host key checking has not been requested, allow | |
d453a600 | 807 | * the connection but without MITM-able authentication or |
aa3378df | 808 | * agent forwarding. |
809 | */ | |
5260325f | 810 | if (options.password_authentication) { |
f49bc4f7 | 811 | error("Password authentication is disabled to avoid " |
812 | "man-in-the-middle attacks."); | |
5260325f | 813 | options.password_authentication = 0; |
814 | } | |
d453a600 | 815 | if (options.kbd_interactive_authentication) { |
816 | error("Keyboard-interactive authentication is disabled" | |
817 | " to avoid man-in-the-middle attacks."); | |
818 | options.kbd_interactive_authentication = 0; | |
819 | options.challenge_response_authentication = 0; | |
820 | } | |
821 | if (options.challenge_response_authentication) { | |
822 | error("Challenge/response authentication is disabled" | |
823 | " to avoid man-in-the-middle attacks."); | |
824 | options.challenge_response_authentication = 0; | |
825 | } | |
5260325f | 826 | if (options.forward_agent) { |
f49bc4f7 | 827 | error("Agent forwarding is disabled to avoid " |
828 | "man-in-the-middle attacks."); | |
5260325f | 829 | options.forward_agent = 0; |
830 | } | |
0b6fbf03 | 831 | if (options.forward_x11) { |
f49bc4f7 | 832 | error("X11 forwarding is disabled to avoid " |
833 | "man-in-the-middle attacks."); | |
0b6fbf03 | 834 | options.forward_x11 = 0; |
835 | } | |
f49bc4f7 | 836 | if (options.num_local_forwards > 0 || |
837 | options.num_remote_forwards > 0) { | |
838 | error("Port forwarding is disabled to avoid " | |
839 | "man-in-the-middle attacks."); | |
840 | options.num_local_forwards = | |
184eed6a | 841 | options.num_remote_forwards = 0; |
0b6fbf03 | 842 | } |
aa3378df | 843 | /* |
844 | * XXX Should permit the user to change to use the new id. | |
845 | * This could be done by converting the host key to an | |
846 | * identifying sentence, tell that the host identifies itself | |
847 | * by that sentence, and ask the user if he/she whishes to | |
848 | * accept the authentication. | |
849 | */ | |
5260325f | 850 | break; |
8a48a7ef | 851 | case HOST_FOUND: |
852 | fatal("internal error"); | |
853 | break; | |
5260325f | 854 | } |
0b6fbf03 | 855 | |
7c49df64 | 856 | if (options.check_host_ip && host_status != HOST_CHANGED && |
857 | ip_status == HOST_CHANGED) { | |
616a6b93 | 858 | snprintf(msg, sizeof(msg), |
859 | "Warning: the %s host key for '%.200s' " | |
860 | "differs from the key for the IP address '%.128s'" | |
861 | "\nOffending key for IP in %s:%d", | |
862 | type, host, ip, ip_file, ip_line); | |
863 | if (host_status == HOST_OK) { | |
864 | len = strlen(msg); | |
865 | snprintf(msg + len, sizeof(msg) - len, | |
866 | "\nMatching host key in %s:%d", | |
7203d6bb | 867 | host_file, host_line); |
616a6b93 | 868 | } |
7c49df64 | 869 | if (options.strict_host_key_checking == 1) { |
b0545fe6 | 870 | logit("%s", msg); |
f49bc4f7 | 871 | error("Exiting, you have requested strict checking."); |
872 | goto fail; | |
7c49df64 | 873 | } else if (options.strict_host_key_checking == 2) { |
616a6b93 | 874 | strlcat(msg, "\nAre you sure you want " |
875 | "to continue connecting (yes/no)? ", sizeof(msg)); | |
876 | if (!confirm(msg)) | |
f49bc4f7 | 877 | goto fail; |
616a6b93 | 878 | } else { |
b0545fe6 | 879 | logit("%s", msg); |
7c49df64 | 880 | } |
881 | } | |
882 | ||
0b6fbf03 | 883 | xfree(ip); |
f49bc4f7 | 884 | return 0; |
885 | ||
886 | fail: | |
887 | xfree(ip); | |
888 | return -1; | |
889 | } | |
890 | ||
21289cd0 | 891 | /* returns 0 if key verifies or -1 if key does NOT verify */ |
f49bc4f7 | 892 | int |
893 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) | |
894 | { | |
895 | struct stat st; | |
0161a13d | 896 | int flags = 0; |
f49bc4f7 | 897 | |
0161a13d | 898 | if (options.verify_host_key_dns && |
899 | verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) { | |
900 | ||
901 | if (flags & DNS_VERIFY_FOUND) { | |
902 | ||
903 | if (options.verify_host_key_dns == 1 && | |
904 | flags & DNS_VERIFY_MATCH && | |
905 | flags & DNS_VERIFY_SECURE) | |
906 | return 0; | |
907 | ||
908 | if (flags & DNS_VERIFY_MATCH) { | |
909 | matching_host_key_dns = 1; | |
910 | } else { | |
911 | warn_changed_key(host_key); | |
912 | error("Update the SSHFP RR in DNS with the new " | |
913 | "host key to get rid of this message."); | |
914 | } | |
21289cd0 | 915 | } |
916 | } | |
21289cd0 | 917 | |
f49bc4f7 | 918 | /* return ok if the key can be found in an old keyfile */ |
919 | if (stat(options.system_hostfile2, &st) == 0 || | |
920 | stat(options.user_hostfile2, &st) == 0) { | |
921 | if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, | |
922 | options.user_hostfile2, options.system_hostfile2) == 0) | |
923 | return 0; | |
924 | } | |
925 | return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, | |
926 | options.user_hostfile, options.system_hostfile); | |
95f1eccc | 927 | } |
928 | ||
8ce64345 | 929 | /* |
a306f2dd | 930 | * Starts a dialog with the server, and authenticates the current user on the |
931 | * server. This does not need any extra privileges. The basic connection | |
932 | * to the server must already have been established before this is called. | |
933 | * If login fails, this function prints an error and never returns. | |
934 | * This function does not require super-user privileges. | |
8ce64345 | 935 | */ |
936 | void | |
39c00dc2 | 937 | ssh_login(Sensitive *sensitive, const char *orighost, |
63bd8c36 | 938 | struct sockaddr *hostaddr, struct passwd *pw) |
8ce64345 | 939 | { |
a306f2dd | 940 | char *host, *cp; |
8ce64345 | 941 | char *server_user, *local_user; |
8ce64345 | 942 | |
8ce64345 | 943 | local_user = xstrdup(pw->pw_name); |
944 | server_user = options.user ? options.user : local_user; | |
945 | ||
7b2ea3a1 | 946 | /* Convert the user-supplied hostname into all lowercase. */ |
947 | host = xstrdup(orighost); | |
948 | for (cp = host; *cp; cp++) | |
949 | if (isupper(*cp)) | |
950 | *cp = tolower(*cp); | |
951 | ||
952 | /* Exchange protocol version identification strings with the server. */ | |
953 | ssh_exchange_identification(); | |
954 | ||
955 | /* Put the connection into non-blocking mode. */ | |
956 | packet_set_nonblocking(); | |
957 | ||
7b2ea3a1 | 958 | /* key exchange */ |
7b2ea3a1 | 959 | /* authenticate user */ |
8ce64345 | 960 | if (compat20) { |
961 | ssh_kex2(host, hostaddr); | |
39c00dc2 | 962 | ssh_userauth2(local_user, server_user, host, sensitive); |
8ce64345 | 963 | } else { |
8ce64345 | 964 | ssh_kex(host, hostaddr); |
39c00dc2 | 965 | ssh_userauth1(local_user, server_user, host, sensitive); |
8ce64345 | 966 | } |
7b2ea3a1 | 967 | } |
0ae4fe1d | 968 | |
969 | void | |
970 | ssh_put_password(char *password) | |
971 | { | |
972 | int size; | |
973 | char *padded; | |
974 | ||
99c415db | 975 | if (datafellows & SSH_BUG_PASSWORDPAD) { |
449c5ba5 | 976 | packet_put_cstring(password); |
99c415db | 977 | return; |
978 | } | |
0ae4fe1d | 979 | size = roundup(strlen(password) + 1, 32); |
980 | padded = xmalloc(size); | |
981 | memset(padded, 0, size); | |
982 | strlcpy(padded, password, size); | |
983 | packet_put_string(padded, size); | |
984 | memset(padded, 0, size); | |
985 | xfree(padded); | |
986 | } | |
8a48a7ef | 987 | |
988 | static int | |
989 | show_key_from_file(const char *file, const char *host, int keytype) | |
990 | { | |
991 | Key *found; | |
992 | char *fp; | |
993 | int line, ret; | |
994 | ||
995 | found = key_new(keytype); | |
996 | if ((ret = lookup_key_in_hostfile_by_type(file, host, | |
997 | keytype, found, &line))) { | |
998 | fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); | |
bbe88b6d | 999 | logit("WARNING: %s key found for host %s\n" |
567a05bf | 1000 | "in %s:%d\n" |
8a48a7ef | 1001 | "%s key fingerprint %s.", |
1002 | key_type(found), host, file, line, | |
1003 | key_type(found), fp); | |
1004 | xfree(fp); | |
1005 | } | |
1006 | key_free(found); | |
1007 | return (ret); | |
1008 | } | |
1009 | ||
1010 | /* print all known host keys for a given host, but skip keys of given type */ | |
1011 | static int | |
1012 | show_other_keys(const char *host, Key *key) | |
1013 | { | |
1014 | int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1}; | |
1015 | int i, found = 0; | |
1016 | ||
1017 | for (i = 0; type[i] != -1; i++) { | |
1018 | if (type[i] == key->type) | |
1019 | continue; | |
1020 | if (type[i] != KEY_RSA1 && | |
1021 | show_key_from_file(options.user_hostfile2, host, type[i])) { | |
1022 | found = 1; | |
1023 | continue; | |
1024 | } | |
1025 | if (type[i] != KEY_RSA1 && | |
1026 | show_key_from_file(options.system_hostfile2, host, type[i])) { | |
1027 | found = 1; | |
1028 | continue; | |
1029 | } | |
1030 | if (show_key_from_file(options.user_hostfile, host, type[i])) { | |
1031 | found = 1; | |
1032 | continue; | |
1033 | } | |
1034 | if (show_key_from_file(options.system_hostfile, host, type[i])) { | |
1035 | found = 1; | |
1036 | continue; | |
1037 | } | |
1038 | debug2("no key of type %d for host %s", type[i], host); | |
1039 | } | |
1040 | return (found); | |
1041 | } | |
1a1bc5d5 | 1042 | |
1043 | static void | |
1044 | warn_changed_key(Key *host_key) | |
1045 | { | |
1046 | char *fp; | |
f5da7f70 | 1047 | const char *type = key_type(host_key); |
1a1bc5d5 | 1048 | |
1049 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); | |
1050 | ||
1051 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1052 | error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); | |
1053 | error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); | |
1054 | error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!"); | |
1055 | error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!"); | |
1056 | error("It is also possible that the %s host key has just been changed.", type); | |
1057 | error("The fingerprint for the %s key sent by the remote host is\n%s.", | |
1058 | type, fp); | |
1059 | error("Please contact your system administrator."); | |
1060 | ||
1061 | xfree(fp); | |
1a1bc5d5 | 1062 | } |