Annotation of src/usr.bin/ssh/sshconnect.c, Revision 1.218
1.218 ! dtucker 1: /* $OpenBSD: sshconnect.c,v 1.217 2010/01/09 23:04:13 dtucker Exp $ */
1.1 deraadt 2: /*
1.39 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * Code to connect to a remote host, and to perform the client side of the
7: * login (authentication) dialog.
1.78 deraadt 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".
1.39 deraadt 14: */
1.1 deraadt 15:
1.174 stevesk 16: #include <sys/types.h>
17: #include <sys/wait.h>
1.175 stevesk 18: #include <sys/stat.h>
1.187 stevesk 19: #include <sys/socket.h>
1.195 stevesk 20: #include <sys/time.h>
1.187 stevesk 21:
22: #include <netinet/in.h>
1.172 stevesk 23:
1.176 stevesk 24: #include <ctype.h>
1.190 stevesk 25: #include <errno.h>
1.216 dtucker 26: #include <fcntl.h>
1.191 stevesk 27: #include <netdb.h>
1.172 stevesk 28: #include <paths.h>
1.199 deraadt 29: #include <signal.h>
1.188 stevesk 30: #include <pwd.h>
1.198 stevesk 31: #include <stdio.h>
1.196 stevesk 32: #include <stdlib.h>
1.193 stevesk 33: #include <string.h>
1.192 stevesk 34: #include <unistd.h>
1.71 markus 35:
1.199 deraadt 36: #include "xmalloc.h"
1.91 markus 37: #include "ssh.h"
1.1 deraadt 38: #include "rsa.h"
1.59 markus 39: #include "buffer.h"
1.1 deraadt 40: #include "packet.h"
41: #include "uidswap.h"
1.21 markus 42: #include "compat.h"
1.58 markus 43: #include "key.h"
1.71 markus 44: #include "sshconnect.h"
1.58 markus 45: #include "hostfile.h"
1.91 markus 46: #include "log.h"
47: #include "readconf.h"
48: #include "atomicio.h"
49: #include "misc.h"
1.140 jakob 50: #include "dns.h"
1.214 andreas 51: #include "roaming.h"
1.186 stevesk 52: #include "version.h"
1.140 jakob 53:
1.70 markus 54: char *client_version_string = NULL;
55: char *server_version_string = NULL;
1.59 markus 56:
1.169 stevesk 57: static int matching_host_key_dns = 0;
1.145 jakob 58:
1.124 markus 59: /* import */
1.43 markus 60: extern Options options;
1.50 markus 61: extern char *__progname;
1.124 markus 62: extern uid_t original_real_uid;
63: extern uid_t original_effective_uid;
1.135 djm 64: extern pid_t proxy_command_pid;
1.91 markus 65:
1.132 markus 66: static int show_other_keys(const char *, Key *);
1.150 jakob 67: static void warn_changed_key(Key *);
1.132 markus 68:
1.39 deraadt 69: /*
70: * Connect to the given ssh server using a proxy command.
71: */
1.109 itojun 72: static int
1.124 markus 73: ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
1.1 deraadt 74: {
1.164 djm 75: char *command_string, *tmp;
1.38 markus 76: int pin[2], pout[2];
1.69 deraadt 77: pid_t pid;
1.201 djm 78: char *shell, strport[NI_MAXSERV];
79:
80: if ((shell = getenv("SHELL")) == NULL)
81: shell = _PATH_BSHELL;
1.38 markus 82:
83: /* Convert the port number into a string. */
1.49 markus 84: snprintf(strport, sizeof strport, "%hu", port);
1.38 markus 85:
1.135 djm 86: /*
87: * Build the final command string in the buffer by making the
88: * appropriate substitutions to the given proxy command.
89: *
1.154 djm 90: * Use "exec" to avoid "sh -c" processes on some platforms
1.135 djm 91: * (e.g. Solaris)
92: */
1.179 djm 93: xasprintf(&tmp, "exec %s", proxy_command);
1.164 djm 94: command_string = percent_expand(tmp, "h", host,
95: "p", strport, (char *)NULL);
96: xfree(tmp);
1.38 markus 97:
98: /* Create pipes for communicating with the proxy. */
99: if (pipe(pin) < 0 || pipe(pout) < 0)
100: fatal("Could not create pipes to communicate with the proxy: %.100s",
1.118 deraadt 101: strerror(errno));
1.38 markus 102:
103: debug("Executing proxy command: %.500s", command_string);
104:
105: /* Fork and execute the proxy command. */
106: if ((pid = fork()) == 0) {
107: char *argv[10];
108:
109: /* Child. Permanently give up superuser privileges. */
1.184 markus 110: permanently_drop_suid(original_real_uid);
1.38 markus 111:
112: /* Redirect stdin and stdout. */
113: close(pin[1]);
114: if (pin[0] != 0) {
115: if (dup2(pin[0], 0) < 0)
116: perror("dup2 stdin");
117: close(pin[0]);
118: }
119: close(pout[0]);
120: if (dup2(pout[1], 1) < 0)
121: perror("dup2 stdout");
122: /* Cannot be 1 because pin allocated two descriptors. */
123: close(pout[1]);
124:
125: /* Stderr is left as it is so that error messages get
126: printed on the user's terminal. */
1.201 djm 127: argv[0] = shell;
1.38 markus 128: argv[1] = "-c";
129: argv[2] = command_string;
130: argv[3] = NULL;
131:
132: /* Execute the proxy command. Note that we gave up any
133: extra privileges above. */
1.89 markus 134: execv(argv[0], argv);
135: perror(argv[0]);
1.38 markus 136: exit(1);
137: }
138: /* Parent. */
139: if (pid < 0)
140: fatal("fork failed: %.100s", strerror(errno));
1.135 djm 141: else
142: proxy_command_pid = pid; /* save pid to clean up later */
1.38 markus 143:
144: /* Close child side of the descriptors. */
145: close(pin[0]);
146: close(pout[1]);
147:
148: /* Free the command name. */
1.164 djm 149: xfree(command_string);
1.38 markus 150:
151: /* Set the connection file descriptors. */
152: packet_set_connection(pout[0], pin[1]);
1.207 dtucker 153: packet_set_timeout(options.server_alive_interval,
154: options.server_alive_count_max);
1.1 deraadt 155:
1.110 markus 156: /* Indicate OK return */
157: return 0;
1.1 deraadt 158: }
159:
1.39 deraadt 160: /*
161: * Creates a (possibly privileged) socket for use as the ssh connection.
162: */
1.109 itojun 163: static int
1.139 markus 164: ssh_create_socket(int privileged, struct addrinfo *ai)
1.1 deraadt 165: {
1.105 markus 166: int sock, gaierr;
167: struct addrinfo hints, *res;
1.1 deraadt 168:
1.40 markus 169: /*
170: * If we are running as root and want to connect to a privileged
171: * port, bind our own socket to a privileged port.
172: */
1.38 markus 173: if (privileged) {
174: int p = IPPORT_RESERVED - 1;
1.124 markus 175: PRIV_START;
1.139 markus 176: sock = rresvport_af(&p, ai->ai_family);
1.124 markus 177: PRIV_END;
1.38 markus 178: if (sock < 0)
1.139 markus 179: error("rresvport: af=%d %.100s", ai->ai_family,
180: strerror(errno));
1.55 markus 181: else
182: debug("Allocated local port %d.", p);
1.105 markus 183: return sock;
184: }
1.217 dtucker 185: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.216 dtucker 186: if (sock < 0) {
1.105 markus 187: error("socket: %.100s", strerror(errno));
1.216 dtucker 188: return -1;
189: }
190: fcntl(sock, F_SETFD, FD_CLOEXEC);
1.105 markus 191:
192: /* Bind the socket to an alternative local IP address */
193: if (options.bind_address == NULL)
194: return sock;
195:
196: memset(&hints, 0, sizeof(hints));
1.139 markus 197: hints.ai_family = ai->ai_family;
198: hints.ai_socktype = ai->ai_socktype;
199: hints.ai_protocol = ai->ai_protocol;
1.105 markus 200: hints.ai_flags = AI_PASSIVE;
1.205 dtucker 201: gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res);
1.105 markus 202: if (gaierr) {
203: error("getaddrinfo: %s: %s", options.bind_address,
1.203 dtucker 204: ssh_gai_strerror(gaierr));
1.105 markus 205: close(sock);
206: return -1;
207: }
208: if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
209: error("bind: %s: %s", options.bind_address, strerror(errno));
210: close(sock);
211: freeaddrinfo(res);
212: return -1;
1.38 markus 213: }
1.105 markus 214: freeaddrinfo(res);
1.38 markus 215: return sock;
1.1 deraadt 216: }
217:
1.141 djm 218: static int
219: timeout_connect(int sockfd, const struct sockaddr *serv_addr,
1.202 djm 220: socklen_t addrlen, int *timeoutp)
1.141 djm 221: {
222: fd_set *fdset;
1.202 djm 223: struct timeval tv, t_start;
1.141 djm 224: socklen_t optlen;
1.179 djm 225: int optval, rc, result = -1;
1.141 djm 226:
1.202 djm 227: gettimeofday(&t_start, NULL);
228:
229: if (*timeoutp <= 0) {
230: result = connect(sockfd, serv_addr, addrlen);
231: goto done;
232: }
1.141 djm 233:
1.156 djm 234: set_nonblock(sockfd);
1.141 djm 235: rc = connect(sockfd, serv_addr, addrlen);
1.156 djm 236: if (rc == 0) {
237: unset_nonblock(sockfd);
1.202 djm 238: result = 0;
239: goto done;
240: }
241: if (errno != EINPROGRESS) {
242: result = -1;
243: goto done;
1.156 djm 244: }
1.141 djm 245:
1.179 djm 246: fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
247: sizeof(fd_mask));
1.141 djm 248: FD_SET(sockfd, fdset);
1.202 djm 249: ms_to_timeval(&tv, *timeoutp);
1.141 djm 250:
1.162 deraadt 251: for (;;) {
1.141 djm 252: rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
253: if (rc != -1 || errno != EINTR)
254: break;
255: }
256:
1.162 deraadt 257: switch (rc) {
1.141 djm 258: case 0:
259: /* Timed out */
260: errno = ETIMEDOUT;
1.142 djm 261: break;
1.141 djm 262: case -1:
263: /* Select error */
1.154 djm 264: debug("select: %s", strerror(errno));
1.142 djm 265: break;
1.141 djm 266: case 1:
267: /* Completed or failed */
268: optval = 0;
269: optlen = sizeof(optval);
1.154 djm 270: if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
1.148 markus 271: &optlen) == -1) {
1.154 djm 272: debug("getsockopt: %s", strerror(errno));
1.142 djm 273: break;
1.148 markus 274: }
1.141 djm 275: if (optval != 0) {
276: errno = optval;
1.142 djm 277: break;
1.141 djm 278: }
1.142 djm 279: result = 0;
1.156 djm 280: unset_nonblock(sockfd);
1.141 djm 281: break;
282: default:
283: /* Should not occur */
284: fatal("Bogus return (%d) from select()", rc);
285: }
286:
1.142 djm 287: xfree(fdset);
1.202 djm 288:
289: done:
290: if (result == 0 && *timeoutp > 0) {
291: ms_subtract_diff(&t_start, timeoutp);
292: if (*timeoutp <= 0) {
293: errno = ETIMEDOUT;
294: result = -1;
295: }
296: }
297:
1.142 djm 298: return (result);
1.141 djm 299: }
300:
1.39 deraadt 301: /*
1.49 markus 302: * Opens a TCP/IP connection to the remote server on the given host.
303: * The address of the remote host will be returned in hostaddr.
1.124 markus 304: * If port is 0, the default port will be used. If needpriv is true,
1.39 deraadt 305: * a privileged port will be allocated to make the connection.
1.124 markus 306: * This requires super-user privileges if needpriv is true.
1.39 deraadt 307: * Connection_attempts specifies the maximum number of tries (one per
308: * second). If proxy_command is non-NULL, it specifies the command (with %h
309: * and %p substituted for host and port, respectively) to use to contact
310: * the daemon.
311: */
1.38 markus 312: int
1.49 markus 313: ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
1.202 djm 314: u_short port, int family, int connection_attempts, int *timeout_ms,
315: int want_keepalive, int needpriv, const char *proxy_command)
1.1 deraadt 316: {
1.90 markus 317: int gaierr;
318: int on = 1;
1.49 markus 319: int sock = -1, attempt;
1.90 markus 320: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.49 markus 321: struct addrinfo hints, *ai, *aitop;
1.38 markus 322:
1.136 markus 323: debug2("ssh_connect: needpriv %d", needpriv);
1.38 markus 324:
325: /* If a proxy command is given, connect using it. */
326: if (proxy_command != NULL)
1.124 markus 327: return ssh_proxy_connect(host, port, proxy_command);
1.38 markus 328:
329: /* No proxy command. */
330:
1.49 markus 331: memset(&hints, 0, sizeof(hints));
1.115 markus 332: hints.ai_family = family;
1.49 markus 333: hints.ai_socktype = SOCK_STREAM;
1.126 deraadt 334: snprintf(strport, sizeof strport, "%u", port);
1.49 markus 335: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
1.203 dtucker 336: fatal("%s: Could not resolve hostname %.100s: %s", __progname,
337: host, ssh_gai_strerror(gaierr));
1.38 markus 338:
1.181 markus 339: for (attempt = 0; attempt < connection_attempts; attempt++) {
1.200 markus 340: if (attempt > 0) {
341: /* Sleep a moment before retrying. */
342: sleep(1);
1.38 markus 343: debug("Trying again...");
1.200 markus 344: }
1.181 markus 345: /*
346: * Loop through addresses for this host, and try each one in
347: * sequence until the connection succeeds.
348: */
1.49 markus 349: for (ai = aitop; ai; ai = ai->ai_next) {
350: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
351: continue;
352: if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
353: ntop, sizeof(ntop), strport, sizeof(strport),
354: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
355: error("ssh_connect: getnameinfo failed");
356: continue;
357: }
358: debug("Connecting to %.200s [%.100s] port %s.",
359: host, ntop, strport);
360:
361: /* Create a socket for connecting. */
1.139 markus 362: sock = ssh_create_socket(needpriv, ai);
1.49 markus 363: if (sock < 0)
1.110 markus 364: /* Any error is already output */
1.49 markus 365: continue;
366:
1.141 djm 367: if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
1.202 djm 368: timeout_ms) >= 0) {
1.49 markus 369: /* Successful connection. */
1.102 markus 370: memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
1.38 markus 371: break;
1.49 markus 372: } else {
1.131 itojun 373: debug("connect to address %s port %s: %s",
374: ntop, strport, strerror(errno));
1.38 markus 375: close(sock);
1.181 markus 376: sock = -1;
1.38 markus 377: }
378: }
1.181 markus 379: if (sock != -1)
1.49 markus 380: break; /* Successful connection. */
1.38 markus 381: }
1.49 markus 382:
383: freeaddrinfo(aitop);
384:
1.38 markus 385: /* Return failure if we didn't get a successful connection. */
1.181 markus 386: if (sock == -1) {
1.159 markus 387: error("ssh: connect to host %s port %s: %s",
1.130 itojun 388: host, strport, strerror(errno));
1.159 markus 389: return (-1);
1.130 itojun 390: }
1.38 markus 391:
392: debug("Connection established.");
1.90 markus 393:
1.155 markus 394: /* Set SO_KEEPALIVE if requested. */
1.202 djm 395: if (want_keepalive &&
1.90 markus 396: setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
397: sizeof(on)) < 0)
398: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.38 markus 399:
400: /* Set the connection. */
401: packet_set_connection(sock, sock);
1.207 dtucker 402: packet_set_timeout(options.server_alive_interval,
403: options.server_alive_count_max);
1.1 deraadt 404:
1.110 markus 405: return 0;
1.59 markus 406: }
407:
1.43 markus 408: /*
1.39 deraadt 409: * Waits for the server identification string, and sends our own
410: * identification string.
411: */
1.213 andreas 412: void
1.202 djm 413: ssh_exchange_identification(int timeout_ms)
1.1 deraadt 414: {
1.38 markus 415: char buf[256], remote_version[256]; /* must be same size! */
1.165 djm 416: int remote_major, remote_minor, mismatch;
1.38 markus 417: int connection_in = packet_get_connection_in();
418: int connection_out = packet_get_connection_out();
1.93 stevesk 419: int minor1 = PROTOCOL_MINOR_1;
1.185 djm 420: u_int i, n;
1.202 djm 421: size_t len;
422: int fdsetsz, remaining, rc;
423: struct timeval t_start, t_remaining;
424: fd_set *fdset;
425:
426: fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask);
427: fdset = xcalloc(1, fdsetsz);
1.38 markus 428:
1.163 avsm 429: /* Read other side's version identification. */
1.202 djm 430: remaining = timeout_ms;
1.185 djm 431: for (n = 0;;) {
1.75 markus 432: for (i = 0; i < sizeof(buf) - 1; i++) {
1.202 djm 433: if (timeout_ms > 0) {
434: gettimeofday(&t_start, NULL);
435: ms_to_timeval(&t_remaining, remaining);
436: FD_SET(connection_in, fdset);
437: rc = select(connection_in + 1, fdset, NULL,
438: fdset, &t_remaining);
439: ms_subtract_diff(&t_start, &remaining);
440: if (rc == 0 || remaining <= 0)
441: fatal("Connection timed out during "
442: "banner exchange");
443: if (rc == -1) {
444: if (errno == EINTR)
445: continue;
446: fatal("ssh_exchange_identification: "
447: "select: %s", strerror(errno));
448: }
449: }
450:
1.214 andreas 451: len = roaming_atomicio(read, connection_in, &buf[i], 1);
1.163 avsm 452:
1.167 djm 453: if (len != 1 && errno == EPIPE)
1.202 djm 454: fatal("ssh_exchange_identification: "
455: "Connection closed by remote host");
1.163 avsm 456: else if (len != 1)
1.202 djm 457: fatal("ssh_exchange_identification: "
458: "read: %.100s", strerror(errno));
1.75 markus 459: if (buf[i] == '\r') {
460: buf[i] = '\n';
461: buf[i + 1] = 0;
462: continue; /**XXX wait for \n */
463: }
464: if (buf[i] == '\n') {
465: buf[i + 1] = 0;
466: break;
467: }
1.185 djm 468: if (++n > 65536)
1.202 djm 469: fatal("ssh_exchange_identification: "
470: "No banner received");
1.38 markus 471: }
1.75 markus 472: buf[sizeof(buf) - 1] = 0;
1.76 markus 473: if (strncmp(buf, "SSH-", 4) == 0)
1.38 markus 474: break;
1.75 markus 475: debug("ssh_exchange_identification: %s", buf);
1.38 markus 476: }
1.59 markus 477: server_version_string = xstrdup(buf);
1.202 djm 478: xfree(fdset);
1.38 markus 479:
1.40 markus 480: /*
481: * Check that the versions match. In future this might accept
482: * several versions and set appropriate flags to handle them.
483: */
1.59 markus 484: if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
485: &remote_major, &remote_minor, remote_version) != 3)
1.38 markus 486: fatal("Bad remote protocol version identification: '%.100s'", buf);
487: debug("Remote protocol version %d.%d, remote software version %.100s",
1.118 deraadt 488: remote_major, remote_minor, remote_version);
1.38 markus 489:
1.59 markus 490: compat_datafellows(remote_version);
1.64 markus 491: mismatch = 0;
1.59 markus 492:
1.116 deraadt 493: switch (remote_major) {
1.64 markus 494: case 1:
495: if (remote_minor == 99 &&
496: (options.protocol & SSH_PROTO_2) &&
497: !(options.protocol & SSH_PROTO_1_PREFERRED)) {
498: enable_compat20();
499: break;
500: }
501: if (!(options.protocol & SSH_PROTO_1)) {
502: mismatch = 1;
503: break;
504: }
505: if (remote_minor < 3) {
506: fatal("Remote machine has too old SSH software version.");
1.81 markus 507: } else if (remote_minor == 3 || remote_minor == 4) {
1.64 markus 508: /* We speak 1.3, too. */
509: enable_compat13();
1.81 markus 510: minor1 = 3;
1.64 markus 511: if (options.forward_agent) {
1.138 itojun 512: logit("Agent forwarding disabled for protocol 1.3");
1.64 markus 513: options.forward_agent = 0;
514: }
515: }
516: break;
517: case 2:
518: if (options.protocol & SSH_PROTO_2) {
519: enable_compat20();
520: break;
1.38 markus 521: }
1.64 markus 522: /* FALLTHROUGH */
1.68 markus 523: default:
1.64 markus 524: mismatch = 1;
525: break;
1.38 markus 526: }
1.64 markus 527: if (mismatch)
1.38 markus 528: fatal("Protocol major versions differ: %d vs. %d",
1.64 markus 529: (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
530: remote_major);
1.38 markus 531: /* Send our own protocol version identification. */
1.211 dtucker 532: snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s%s",
1.64 markus 533: compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
1.81 markus 534: compat20 ? PROTOCOL_MINOR_2 : minor1,
1.211 dtucker 535: SSH_VERSION, compat20 ? "\r\n" : "\n");
1.214 andreas 536: if (roaming_atomicio(vwrite, connection_out, buf, strlen(buf))
537: != strlen(buf))
1.38 markus 538: fatal("write: %.100s", strerror(errno));
1.59 markus 539: client_version_string = xstrdup(buf);
540: chop(client_version_string);
541: chop(server_version_string);
542: debug("Local version string %.100s", client_version_string);
1.1 deraadt 543: }
544:
1.96 markus 545: /* defaults to 'no' */
1.109 itojun 546: static int
1.112 markus 547: confirm(const char *prompt)
1.1 deraadt 548: {
1.119 markus 549: const char *msg, *again = "Please type 'yes' or 'no': ";
550: char *p;
551: int ret = -1;
1.96 markus 552:
553: if (options.batch_mode)
554: return 0;
1.119 markus 555: for (msg = prompt;;msg = again) {
556: p = read_passphrase(msg, RP_ECHO);
557: if (p == NULL ||
558: (p[0] == '\0') || (p[0] == '\n') ||
559: strncasecmp(p, "no", 2) == 0)
560: ret = 0;
1.127 markus 561: if (p && strncasecmp(p, "yes", 3) == 0)
1.119 markus 562: ret = 1;
563: if (p)
564: xfree(p);
565: if (ret != -1)
566: return ret;
1.1 deraadt 567: }
568: }
569:
1.39 deraadt 570: /*
1.108 markus 571: * check whether the supplied host key is valid, return -1 if the key
572: * is not valid. the user_hostfile will not be updated if 'readonly' is true.
1.39 deraadt 573: */
1.197 dtucker 574: #define RDRW 0
575: #define RDONLY 1
576: #define ROQUIET 2
1.109 itojun 577: static int
1.197 dtucker 578: check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
579: Key *host_key, int readonly, const char *user_hostfile,
580: const char *system_hostfile)
1.1 deraadt 581: {
1.58 markus 582: Key *file_key;
1.152 jakob 583: const char *type = key_type(host_key);
1.189 dtucker 584: char *ip = NULL, *host = NULL;
1.204 grunk 585: char hostline[1000], *hostp, *fp, *ra;
1.38 markus 586: HostStatus host_status;
587: HostStatus ip_status;
1.161 djm 588: int r, local = 0, host_ip_differ = 0;
1.49 markus 589: char ntop[NI_MAXHOST];
1.119 markus 590: char msg[1024];
1.210 dtucker 591: int len, host_line, ip_line, cancelled_forwarding = 0;
1.85 markus 592: const char *host_file = NULL, *ip_file = NULL;
1.49 markus 593:
594: /*
595: * Force accepting of the host key for loopback/localhost. The
596: * problem is that if the home directory is NFS-mounted to multiple
597: * machines, localhost will refer to a different machine in each of
598: * them, and the user will get bogus HOST_CHANGED warnings. This
599: * essentially disables host authentication for localhost; however,
600: * this is probably not a real problem.
601: */
1.70 markus 602: /** hostaddr == 0! */
1.49 markus 603: switch (hostaddr->sa_family) {
604: case AF_INET:
1.108 markus 605: local = (ntohl(((struct sockaddr_in *)hostaddr)->
1.168 djm 606: sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
1.49 markus 607: break;
608: case AF_INET6:
1.108 markus 609: local = IN6_IS_ADDR_LOOPBACK(
610: &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
1.49 markus 611: break;
612: default:
613: local = 0;
614: break;
615: }
1.111 markus 616: if (options.no_host_authentication_for_localhost == 1 && local &&
617: options.host_key_alias == NULL) {
1.88 markus 618: debug("Forcing accepting of host key for "
619: "loopback/localhost.");
1.108 markus 620: return 0;
1.49 markus 621: }
1.42 markus 622:
623: /*
1.88 markus 624: * We don't have the remote ip-address for connections
625: * using a proxy command
1.42 markus 626: */
1.84 markus 627: if (options.proxy_command == NULL) {
628: if (getnameinfo(hostaddr, hostaddr->sa_len, ntop, sizeof(ntop),
1.86 markus 629: NULL, 0, NI_NUMERICHOST) != 0)
1.84 markus 630: fatal("check_host_key: getnameinfo failed");
1.197 dtucker 631: ip = put_host_port(ntop, port);
1.84 markus 632: } else {
633: ip = xstrdup("<no hostip for proxy command>");
1.86 markus 634: }
1.206 grunk 635:
636: /*
1.88 markus 637: * Turn off check_host_ip if the connection is to localhost, via proxy
638: * command or if we don't have a hostname to compare with
639: */
1.189 dtucker 640: if (options.check_host_ip && (local ||
641: strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
1.88 markus 642: options.check_host_ip = 0;
1.86 markus 643:
644: /*
1.189 dtucker 645: * Allow the user to record the key under a different name or
646: * differentiate a non-standard port. This is useful for ssh
647: * tunneling over forwarded connections or if you run multiple
648: * sshd's on different ports on the same machine.
1.86 markus 649: */
650: if (options.host_key_alias != NULL) {
1.189 dtucker 651: host = xstrdup(options.host_key_alias);
1.86 markus 652: debug("using hostkeyalias: %s", host);
1.189 dtucker 653: } else {
1.197 dtucker 654: host = put_host_port(hostname, port);
1.84 markus 655: }
1.38 markus 656:
1.46 markus 657: /*
658: * Store the host key from the known host file in here so that we can
659: * compare it with the key for the IP address.
660: */
1.58 markus 661: file_key = key_new(host_key->type);
1.38 markus 662:
1.40 markus 663: /*
1.170 djm 664: * Check if the host key is present in the user's list of known
1.40 markus 665: * hosts or in the systemwide list.
666: */
1.85 markus 667: host_file = user_hostfile;
1.108 markus 668: host_status = check_host_in_hostfile(host_file, host, host_key,
1.118 deraadt 669: file_key, &host_line);
1.85 markus 670: if (host_status == HOST_NEW) {
671: host_file = system_hostfile;
1.108 markus 672: host_status = check_host_in_hostfile(host_file, host, host_key,
673: file_key, &host_line);
1.85 markus 674: }
1.40 markus 675: /*
676: * Also perform check for the ip address, skip the check if we are
677: * localhost or the hostname was an ip address to begin with
678: */
1.88 markus 679: if (options.check_host_ip) {
1.58 markus 680: Key *ip_key = key_new(host_key->type);
1.38 markus 681:
1.85 markus 682: ip_file = user_hostfile;
1.108 markus 683: ip_status = check_host_in_hostfile(ip_file, ip, host_key,
684: ip_key, &ip_line);
1.85 markus 685: if (ip_status == HOST_NEW) {
686: ip_file = system_hostfile;
1.108 markus 687: ip_status = check_host_in_hostfile(ip_file, ip,
688: host_key, ip_key, &ip_line);
1.85 markus 689: }
1.38 markus 690: if (host_status == HOST_CHANGED &&
1.58 markus 691: (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
1.38 markus 692: host_ip_differ = 1;
693:
1.58 markus 694: key_free(ip_key);
1.38 markus 695: } else
696: ip_status = host_status;
697:
1.58 markus 698: key_free(file_key);
1.38 markus 699:
700: switch (host_status) {
701: case HOST_OK:
702: /* The host is known and the key matches. */
1.72 markus 703: debug("Host '%.200s' is known and matches the %s host key.",
704: host, type);
1.85 markus 705: debug("Found key in %s:%d", host_file, host_line);
1.88 markus 706: if (options.check_host_ip && ip_status == HOST_NEW) {
1.108 markus 707: if (readonly)
1.138 itojun 708: logit("%s host key for IP address "
1.108 markus 709: "'%.128s' not in list of known hosts.",
710: type, ip);
711: else if (!add_host_to_hostfile(user_hostfile, ip,
1.160 djm 712: host_key, options.hash_known_hosts))
1.138 itojun 713: logit("Failed to add the %s host key for IP "
1.108 markus 714: "address '%.128s' to the list of known "
715: "hosts (%.30s).", type, ip, user_hostfile);
1.88 markus 716: else
1.138 itojun 717: logit("Warning: Permanently added the %s host "
1.108 markus 718: "key for IP address '%.128s' to the list "
719: "of known hosts.", type, ip);
1.209 grunk 720: } else if (options.visual_host_key) {
1.204 grunk 721: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
722: ra = key_fingerprint(host_key, SSH_FP_MD5,
723: SSH_FP_RANDOMART);
724: logit("Host key fingerprint is %s\n%s\n", fp, ra);
725: xfree(ra);
726: xfree(fp);
1.38 markus 727: }
728: break;
729: case HOST_NEW:
1.197 dtucker 730: if (options.host_key_alias == NULL && port != 0 &&
731: port != SSH_DEFAULT_PORT) {
732: debug("checking without port identifier");
1.212 stevesk 733: if (check_host_key(hostname, hostaddr, 0, host_key,
734: ROQUIET, user_hostfile, system_hostfile) == 0) {
1.197 dtucker 735: debug("found matching key w/out port");
736: break;
737: }
738: }
1.108 markus 739: if (readonly)
740: goto fail;
1.38 markus 741: /* The host is new. */
742: if (options.strict_host_key_checking == 1) {
1.108 markus 743: /*
744: * User has requested strict host key checking. We
745: * will not add the host key automatically. The only
746: * alternative left is to abort.
747: */
748: error("No %s host key is known for %.200s and you "
749: "have requested strict checking.", type, host);
750: goto fail;
1.38 markus 751: } else if (options.strict_host_key_checking == 2) {
1.145 jakob 752: char msg1[1024], msg2[1024];
753:
754: if (show_other_keys(host, host_key))
755: snprintf(msg1, sizeof(msg1),
1.168 djm 756: "\nbut keys of different type are already"
757: " known for this host.");
1.145 jakob 758: else
759: snprintf(msg1, sizeof(msg1), ".");
1.38 markus 760: /* The default */
1.100 markus 761: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 762: ra = key_fingerprint(host_key, SSH_FP_MD5,
763: SSH_FP_RANDOMART);
1.145 jakob 764: msg2[0] = '\0';
765: if (options.verify_host_key_dns) {
1.153 jakob 766: if (matching_host_key_dns)
1.145 jakob 767: snprintf(msg2, sizeof(msg2),
768: "Matching host key fingerprint"
769: " found in DNS.\n");
770: else
771: snprintf(msg2, sizeof(msg2),
772: "No matching host key fingerprint"
773: " found in DNS.\n");
774: }
1.119 markus 775: snprintf(msg, sizeof(msg),
1.108 markus 776: "The authenticity of host '%.200s (%s)' can't be "
1.132 markus 777: "established%s\n"
1.209 grunk 778: "%s key fingerprint is %s.%s%s\n%s"
1.108 markus 779: "Are you sure you want to continue connecting "
1.132 markus 780: "(yes/no)? ",
1.209 grunk 781: host, ip, msg1, type, fp,
782: options.visual_host_key ? "\n" : "",
783: options.visual_host_key ? ra : "",
784: msg2);
1.204 grunk 785: xfree(ra);
1.100 markus 786: xfree(fp);
1.119 markus 787: if (!confirm(msg))
1.108 markus 788: goto fail;
1.38 markus 789: }
1.161 djm 790: /*
791: * If not in strict mode, add the key automatically to the
792: * local known_hosts file.
793: */
1.88 markus 794: if (options.check_host_ip && ip_status == HOST_NEW) {
1.161 djm 795: snprintf(hostline, sizeof(hostline), "%s,%s",
796: host, ip);
1.38 markus 797: hostp = hostline;
1.161 djm 798: if (options.hash_known_hosts) {
799: /* Add hash of host and IP separately */
800: r = add_host_to_hostfile(user_hostfile, host,
801: host_key, options.hash_known_hosts) &&
802: add_host_to_hostfile(user_hostfile, ip,
803: host_key, options.hash_known_hosts);
804: } else {
805: /* Add unhashed "host,ip" */
806: r = add_host_to_hostfile(user_hostfile,
807: hostline, host_key,
808: options.hash_known_hosts);
809: }
810: } else {
811: r = add_host_to_hostfile(user_hostfile, host, host_key,
812: options.hash_known_hosts);
1.38 markus 813: hostp = host;
1.161 djm 814: }
1.38 markus 815:
1.161 djm 816: if (!r)
1.138 itojun 817: logit("Failed to add the host to the list of known "
1.108 markus 818: "hosts (%.500s).", user_hostfile);
1.38 markus 819: else
1.138 itojun 820: logit("Warning: Permanently added '%.200s' (%s) to the "
1.108 markus 821: "list of known hosts.", hostp, type);
1.38 markus 822: break;
823: case HOST_CHANGED:
1.197 dtucker 824: if (readonly == ROQUIET)
825: goto fail;
1.38 markus 826: if (options.check_host_ip && host_ip_differ) {
1.158 avsm 827: char *key_msg;
1.38 markus 828: if (ip_status == HOST_NEW)
1.158 avsm 829: key_msg = "is unknown";
1.38 markus 830: else if (ip_status == HOST_OK)
1.158 avsm 831: key_msg = "is unchanged";
1.38 markus 832: else
1.158 avsm 833: key_msg = "has a different value";
1.38 markus 834: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
835: error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
836: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1.72 markus 837: error("The %s host key for %s has changed,", type, host);
1.208 ian 838: error("and the key for the corresponding IP address %s", ip);
1.158 avsm 839: error("%s. This could either mean that", key_msg);
1.38 markus 840: error("DNS SPOOFING is happening or the IP address for the host");
1.85 markus 841: error("and its host key have changed at the same time.");
1.88 markus 842: if (ip_status != HOST_NEW)
1.85 markus 843: error("Offending key for IP in %s:%d", ip_file, ip_line);
1.38 markus 844: }
845: /* The host key has changed. */
1.150 jakob 846: warn_changed_key(host_key);
1.38 markus 847: error("Add correct host key in %.100s to get rid of this message.",
1.87 markus 848: user_hostfile);
1.85 markus 849: error("Offending key in %s:%d", host_file, host_line);
1.38 markus 850:
1.40 markus 851: /*
852: * If strict host key checking is in use, the user will have
853: * to edit the key manually and we can only abort.
854: */
1.108 markus 855: if (options.strict_host_key_checking) {
856: error("%s host key for %.200s has changed and you have "
857: "requested strict checking.", type, host);
858: goto fail;
859: }
1.38 markus 860:
1.40 markus 861: /*
862: * If strict host key checking has not been requested, allow
1.144 djm 863: * the connection but without MITM-able authentication or
1.194 stevesk 864: * forwarding.
1.40 markus 865: */
1.38 markus 866: if (options.password_authentication) {
1.108 markus 867: error("Password authentication is disabled to avoid "
868: "man-in-the-middle attacks.");
1.38 markus 869: options.password_authentication = 0;
1.210 dtucker 870: cancelled_forwarding = 1;
1.144 djm 871: }
872: if (options.kbd_interactive_authentication) {
873: error("Keyboard-interactive authentication is disabled"
874: " to avoid man-in-the-middle attacks.");
875: options.kbd_interactive_authentication = 0;
876: options.challenge_response_authentication = 0;
1.210 dtucker 877: cancelled_forwarding = 1;
1.144 djm 878: }
879: if (options.challenge_response_authentication) {
880: error("Challenge/response authentication is disabled"
881: " to avoid man-in-the-middle attacks.");
882: options.challenge_response_authentication = 0;
1.210 dtucker 883: cancelled_forwarding = 1;
1.38 markus 884: }
885: if (options.forward_agent) {
1.108 markus 886: error("Agent forwarding is disabled to avoid "
887: "man-in-the-middle attacks.");
1.38 markus 888: options.forward_agent = 0;
1.210 dtucker 889: cancelled_forwarding = 1;
1.83 markus 890: }
891: if (options.forward_x11) {
1.108 markus 892: error("X11 forwarding is disabled to avoid "
893: "man-in-the-middle attacks.");
1.83 markus 894: options.forward_x11 = 0;
1.210 dtucker 895: cancelled_forwarding = 1;
1.83 markus 896: }
1.108 markus 897: if (options.num_local_forwards > 0 ||
898: options.num_remote_forwards > 0) {
899: error("Port forwarding is disabled to avoid "
900: "man-in-the-middle attacks.");
901: options.num_local_forwards =
1.118 deraadt 902: options.num_remote_forwards = 0;
1.210 dtucker 903: cancelled_forwarding = 1;
1.194 stevesk 904: }
905: if (options.tun_open != SSH_TUNMODE_NO) {
906: error("Tunnel forwarding is disabled to avoid "
907: "man-in-the-middle attacks.");
908: options.tun_open = SSH_TUNMODE_NO;
1.210 dtucker 909: cancelled_forwarding = 1;
1.38 markus 910: }
1.210 dtucker 911: if (options.exit_on_forward_failure && cancelled_forwarding)
912: fatal("Error: forwarding disabled due to host key "
913: "check failure");
914:
1.40 markus 915: /*
916: * XXX Should permit the user to change to use the new id.
917: * This could be done by converting the host key to an
918: * identifying sentence, tell that the host identifies itself
1.218 ! dtucker 919: * by that sentence, and ask the user if he/she wishes to
1.40 markus 920: * accept the authentication.
921: */
1.38 markus 922: break;
1.132 markus 923: case HOST_FOUND:
924: fatal("internal error");
925: break;
1.88 markus 926: }
927:
928: if (options.check_host_ip && host_status != HOST_CHANGED &&
929: ip_status == HOST_CHANGED) {
1.119 markus 930: snprintf(msg, sizeof(msg),
931: "Warning: the %s host key for '%.200s' "
932: "differs from the key for the IP address '%.128s'"
933: "\nOffending key for IP in %s:%d",
934: type, host, ip, ip_file, ip_line);
935: if (host_status == HOST_OK) {
936: len = strlen(msg);
937: snprintf(msg + len, sizeof(msg) - len,
938: "\nMatching host key in %s:%d",
1.125 deraadt 939: host_file, host_line);
1.119 markus 940: }
1.88 markus 941: if (options.strict_host_key_checking == 1) {
1.143 djm 942: logit("%s", msg);
1.108 markus 943: error("Exiting, you have requested strict checking.");
944: goto fail;
1.88 markus 945: } else if (options.strict_host_key_checking == 2) {
1.119 markus 946: strlcat(msg, "\nAre you sure you want "
947: "to continue connecting (yes/no)? ", sizeof(msg));
948: if (!confirm(msg))
1.108 markus 949: goto fail;
1.119 markus 950: } else {
1.143 djm 951: logit("%s", msg);
1.88 markus 952: }
1.38 markus 953: }
1.82 provos 954:
955: xfree(ip);
1.189 dtucker 956: xfree(host);
1.108 markus 957: return 0;
958:
959: fail:
960: xfree(ip);
1.189 dtucker 961: xfree(host);
1.108 markus 962: return -1;
963: }
964:
1.140 jakob 965: /* returns 0 if key verifies or -1 if key does NOT verify */
1.108 markus 966: int
967: verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
968: {
969: struct stat st;
1.153 jakob 970: int flags = 0;
1.140 jakob 971:
1.153 jakob 972: if (options.verify_host_key_dns &&
973: verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
974:
975: if (flags & DNS_VERIFY_FOUND) {
976:
977: if (options.verify_host_key_dns == 1 &&
978: flags & DNS_VERIFY_MATCH &&
979: flags & DNS_VERIFY_SECURE)
980: return 0;
981:
982: if (flags & DNS_VERIFY_MATCH) {
983: matching_host_key_dns = 1;
984: } else {
985: warn_changed_key(host_key);
986: error("Update the SSHFP RR in DNS with the new "
987: "host key to get rid of this message.");
988: }
1.140 jakob 989: }
990: }
1.108 markus 991:
992: /* return ok if the key can be found in an old keyfile */
993: if (stat(options.system_hostfile2, &st) == 0 ||
994: stat(options.user_hostfile2, &st) == 0) {
1.197 dtucker 995: if (check_host_key(host, hostaddr, options.port, host_key,
996: RDONLY, options.user_hostfile2,
997: options.system_hostfile2) == 0)
1.108 markus 998: return 0;
999: }
1.197 dtucker 1000: return check_host_key(host, hostaddr, options.port, host_key,
1001: RDRW, options.user_hostfile, options.system_hostfile);
1.51 markus 1002: }
1.70 markus 1003:
1.51 markus 1004: /*
1005: * Starts a dialog with the server, and authenticates the current user on the
1006: * server. This does not need any extra privileges. The basic connection
1007: * to the server must already have been established before this is called.
1008: * If login fails, this function prints an error and never returns.
1009: * This function does not require super-user privileges.
1010: */
1011: void
1.120 markus 1012: ssh_login(Sensitive *sensitive, const char *orighost,
1.202 djm 1013: struct sockaddr *hostaddr, struct passwd *pw, int timeout_ms)
1.51 markus 1014: {
1015: char *host, *cp;
1.70 markus 1016: char *server_user, *local_user;
1017:
1018: local_user = xstrdup(pw->pw_name);
1019: server_user = options.user ? options.user : local_user;
1.51 markus 1020:
1021: /* Convert the user-supplied hostname into all lowercase. */
1022: host = xstrdup(orighost);
1023: for (cp = host; *cp; cp++)
1024: if (isupper(*cp))
1.178 deraadt 1025: *cp = (char)tolower(*cp);
1.51 markus 1026:
1027: /* Exchange protocol version identification strings with the server. */
1.202 djm 1028: ssh_exchange_identification(timeout_ms);
1.51 markus 1029:
1030: /* Put the connection into non-blocking mode. */
1031: packet_set_nonblocking();
1032:
1033: /* key exchange */
1034: /* authenticate user */
1.59 markus 1035: if (compat20) {
1036: ssh_kex2(host, hostaddr);
1.120 markus 1037: ssh_userauth2(local_user, server_user, host, sensitive);
1.59 markus 1038: } else {
1039: ssh_kex(host, hostaddr);
1.120 markus 1040: ssh_userauth1(local_user, server_user, host, sensitive);
1.59 markus 1041: }
1.182 markus 1042: xfree(local_user);
1.97 markus 1043: }
1044:
1045: void
1046: ssh_put_password(char *password)
1047: {
1048: int size;
1049: char *padded;
1050:
1.99 deraadt 1051: if (datafellows & SSH_BUG_PASSWORDPAD) {
1.107 markus 1052: packet_put_cstring(password);
1.99 deraadt 1053: return;
1054: }
1.97 markus 1055: size = roundup(strlen(password) + 1, 32);
1.179 djm 1056: padded = xcalloc(1, size);
1.97 markus 1057: strlcpy(padded, password, size);
1058: packet_put_string(padded, size);
1059: memset(padded, 0, size);
1060: xfree(padded);
1.132 markus 1061: }
1062:
1063: static int
1064: show_key_from_file(const char *file, const char *host, int keytype)
1065: {
1066: Key *found;
1.204 grunk 1067: char *fp, *ra;
1.132 markus 1068: int line, ret;
1069:
1070: found = key_new(keytype);
1071: if ((ret = lookup_key_in_hostfile_by_type(file, host,
1072: keytype, found, &line))) {
1073: fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 1074: ra = key_fingerprint(found, SSH_FP_MD5, SSH_FP_RANDOMART);
1.138 itojun 1075: logit("WARNING: %s key found for host %s\n"
1.133 markus 1076: "in %s:%d\n"
1.204 grunk 1077: "%s key fingerprint %s.\n%s\n",
1.132 markus 1078: key_type(found), host, file, line,
1.204 grunk 1079: key_type(found), fp, ra);
1080: xfree(ra);
1.132 markus 1081: xfree(fp);
1082: }
1083: key_free(found);
1084: return (ret);
1085: }
1086:
1087: /* print all known host keys for a given host, but skip keys of given type */
1088: static int
1089: show_other_keys(const char *host, Key *key)
1090: {
1091: int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1};
1092: int i, found = 0;
1093:
1094: for (i = 0; type[i] != -1; i++) {
1095: if (type[i] == key->type)
1096: continue;
1097: if (type[i] != KEY_RSA1 &&
1098: show_key_from_file(options.user_hostfile2, host, type[i])) {
1099: found = 1;
1100: continue;
1101: }
1102: if (type[i] != KEY_RSA1 &&
1103: show_key_from_file(options.system_hostfile2, host, type[i])) {
1104: found = 1;
1105: continue;
1106: }
1107: if (show_key_from_file(options.user_hostfile, host, type[i])) {
1108: found = 1;
1109: continue;
1110: }
1111: if (show_key_from_file(options.system_hostfile, host, type[i])) {
1112: found = 1;
1113: continue;
1114: }
1115: debug2("no key of type %d for host %s", type[i], host);
1116: }
1117: return (found);
1.150 jakob 1118: }
1119:
1120: static void
1121: warn_changed_key(Key *host_key)
1122: {
1123: char *fp;
1.151 jakob 1124: const char *type = key_type(host_key);
1.150 jakob 1125:
1126: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1127:
1128: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1129: error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1130: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1131: error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1132: error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1133: error("It is also possible that the %s host key has just been changed.", type);
1134: error("The fingerprint for the %s key sent by the remote host is\n%s.",
1135: type, fp);
1136: error("Please contact your system administrator.");
1137:
1138: xfree(fp);
1.171 reyk 1139: }
1140:
1141: /*
1142: * Execute a local command
1143: */
1144: int
1145: ssh_local_cmd(const char *args)
1146: {
1147: char *shell;
1148: pid_t pid;
1149: int status;
1150:
1151: if (!options.permit_local_command ||
1152: args == NULL || !*args)
1153: return (1);
1154:
1155: if ((shell = getenv("SHELL")) == NULL)
1156: shell = _PATH_BSHELL;
1157:
1158: pid = fork();
1159: if (pid == 0) {
1160: debug3("Executing %s -c \"%s\"", shell, args);
1161: execl(shell, shell, "-c", args, (char *)NULL);
1162: error("Couldn't execute %s -c \"%s\": %s",
1163: shell, args, strerror(errno));
1164: _exit(1);
1165: } else if (pid == -1)
1166: fatal("fork failed: %.100s", strerror(errno));
1167: while (waitpid(pid, &status, 0) == -1)
1168: if (errno != EINTR)
1169: fatal("Couldn't wait for child: %s", strerror(errno));
1170:
1171: if (!WIFEXITED(status))
1172: return (1);
1173:
1174: return (WEXITSTATUS(status));
1.1 deraadt 1175: }
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