Annotation of src/usr.bin/ssh/sshconnect.c, Revision 1.210
1.210 ! dtucker 1: /* $OpenBSD: sshconnect.c,v 1.209 2008/06/26 11:46:31 grunk 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>
1.191 stevesk 26: #include <netdb.h>
1.172 stevesk 27: #include <paths.h>
1.199 deraadt 28: #include <signal.h>
1.188 stevesk 29: #include <pwd.h>
1.198 stevesk 30: #include <stdio.h>
1.196 stevesk 31: #include <stdlib.h>
1.193 stevesk 32: #include <string.h>
1.192 stevesk 33: #include <unistd.h>
1.71 markus 34:
1.199 deraadt 35: #include "xmalloc.h"
1.91 markus 36: #include "ssh.h"
1.1 deraadt 37: #include "rsa.h"
1.59 markus 38: #include "buffer.h"
1.1 deraadt 39: #include "packet.h"
40: #include "uidswap.h"
1.21 markus 41: #include "compat.h"
1.58 markus 42: #include "key.h"
1.71 markus 43: #include "sshconnect.h"
1.58 markus 44: #include "hostfile.h"
1.91 markus 45: #include "log.h"
46: #include "readconf.h"
47: #include "atomicio.h"
48: #include "misc.h"
1.140 jakob 49: #include "dns.h"
1.186 stevesk 50: #include "version.h"
1.140 jakob 51:
1.70 markus 52: char *client_version_string = NULL;
53: char *server_version_string = NULL;
1.59 markus 54:
1.169 stevesk 55: static int matching_host_key_dns = 0;
1.145 jakob 56:
1.124 markus 57: /* import */
1.43 markus 58: extern Options options;
1.50 markus 59: extern char *__progname;
1.124 markus 60: extern uid_t original_real_uid;
61: extern uid_t original_effective_uid;
1.135 djm 62: extern pid_t proxy_command_pid;
1.91 markus 63:
1.132 markus 64: static int show_other_keys(const char *, Key *);
1.150 jakob 65: static void warn_changed_key(Key *);
1.132 markus 66:
1.39 deraadt 67: /*
68: * Connect to the given ssh server using a proxy command.
69: */
1.109 itojun 70: static int
1.124 markus 71: ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
1.1 deraadt 72: {
1.164 djm 73: char *command_string, *tmp;
1.38 markus 74: int pin[2], pout[2];
1.69 deraadt 75: pid_t pid;
1.201 djm 76: char *shell, strport[NI_MAXSERV];
77:
78: if ((shell = getenv("SHELL")) == NULL)
79: shell = _PATH_BSHELL;
1.38 markus 80:
81: /* Convert the port number into a string. */
1.49 markus 82: snprintf(strport, sizeof strport, "%hu", port);
1.38 markus 83:
1.135 djm 84: /*
85: * Build the final command string in the buffer by making the
86: * appropriate substitutions to the given proxy command.
87: *
1.154 djm 88: * Use "exec" to avoid "sh -c" processes on some platforms
1.135 djm 89: * (e.g. Solaris)
90: */
1.179 djm 91: xasprintf(&tmp, "exec %s", proxy_command);
1.164 djm 92: command_string = percent_expand(tmp, "h", host,
93: "p", strport, (char *)NULL);
94: xfree(tmp);
1.38 markus 95:
96: /* Create pipes for communicating with the proxy. */
97: if (pipe(pin) < 0 || pipe(pout) < 0)
98: fatal("Could not create pipes to communicate with the proxy: %.100s",
1.118 deraadt 99: strerror(errno));
1.38 markus 100:
101: debug("Executing proxy command: %.500s", command_string);
102:
103: /* Fork and execute the proxy command. */
104: if ((pid = fork()) == 0) {
105: char *argv[10];
106:
107: /* Child. Permanently give up superuser privileges. */
1.184 markus 108: permanently_drop_suid(original_real_uid);
1.38 markus 109:
110: /* Redirect stdin and stdout. */
111: close(pin[1]);
112: if (pin[0] != 0) {
113: if (dup2(pin[0], 0) < 0)
114: perror("dup2 stdin");
115: close(pin[0]);
116: }
117: close(pout[0]);
118: if (dup2(pout[1], 1) < 0)
119: perror("dup2 stdout");
120: /* Cannot be 1 because pin allocated two descriptors. */
121: close(pout[1]);
122:
123: /* Stderr is left as it is so that error messages get
124: printed on the user's terminal. */
1.201 djm 125: argv[0] = shell;
1.38 markus 126: argv[1] = "-c";
127: argv[2] = command_string;
128: argv[3] = NULL;
129:
130: /* Execute the proxy command. Note that we gave up any
131: extra privileges above. */
1.89 markus 132: execv(argv[0], argv);
133: perror(argv[0]);
1.38 markus 134: exit(1);
135: }
136: /* Parent. */
137: if (pid < 0)
138: fatal("fork failed: %.100s", strerror(errno));
1.135 djm 139: else
140: proxy_command_pid = pid; /* save pid to clean up later */
1.38 markus 141:
142: /* Close child side of the descriptors. */
143: close(pin[0]);
144: close(pout[1]);
145:
146: /* Free the command name. */
1.164 djm 147: xfree(command_string);
1.38 markus 148:
149: /* Set the connection file descriptors. */
150: packet_set_connection(pout[0], pin[1]);
1.207 dtucker 151: packet_set_timeout(options.server_alive_interval,
152: options.server_alive_count_max);
1.1 deraadt 153:
1.110 markus 154: /* Indicate OK return */
155: return 0;
1.1 deraadt 156: }
157:
1.39 deraadt 158: /*
159: * Creates a (possibly privileged) socket for use as the ssh connection.
160: */
1.109 itojun 161: static int
1.139 markus 162: ssh_create_socket(int privileged, struct addrinfo *ai)
1.1 deraadt 163: {
1.105 markus 164: int sock, gaierr;
165: struct addrinfo hints, *res;
1.1 deraadt 166:
1.40 markus 167: /*
168: * If we are running as root and want to connect to a privileged
169: * port, bind our own socket to a privileged port.
170: */
1.38 markus 171: if (privileged) {
172: int p = IPPORT_RESERVED - 1;
1.124 markus 173: PRIV_START;
1.139 markus 174: sock = rresvport_af(&p, ai->ai_family);
1.124 markus 175: PRIV_END;
1.38 markus 176: if (sock < 0)
1.139 markus 177: error("rresvport: af=%d %.100s", ai->ai_family,
178: strerror(errno));
1.55 markus 179: else
180: debug("Allocated local port %d.", p);
1.105 markus 181: return sock;
182: }
1.139 markus 183: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.105 markus 184: if (sock < 0)
185: error("socket: %.100s", strerror(errno));
186:
187: /* Bind the socket to an alternative local IP address */
188: if (options.bind_address == NULL)
189: return sock;
190:
191: memset(&hints, 0, sizeof(hints));
1.139 markus 192: hints.ai_family = ai->ai_family;
193: hints.ai_socktype = ai->ai_socktype;
194: hints.ai_protocol = ai->ai_protocol;
1.105 markus 195: hints.ai_flags = AI_PASSIVE;
1.205 dtucker 196: gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res);
1.105 markus 197: if (gaierr) {
198: error("getaddrinfo: %s: %s", options.bind_address,
1.203 dtucker 199: ssh_gai_strerror(gaierr));
1.105 markus 200: close(sock);
201: return -1;
202: }
203: if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
204: error("bind: %s: %s", options.bind_address, strerror(errno));
205: close(sock);
206: freeaddrinfo(res);
207: return -1;
1.38 markus 208: }
1.105 markus 209: freeaddrinfo(res);
1.38 markus 210: return sock;
1.1 deraadt 211: }
212:
1.141 djm 213: static int
214: timeout_connect(int sockfd, const struct sockaddr *serv_addr,
1.202 djm 215: socklen_t addrlen, int *timeoutp)
1.141 djm 216: {
217: fd_set *fdset;
1.202 djm 218: struct timeval tv, t_start;
1.141 djm 219: socklen_t optlen;
1.179 djm 220: int optval, rc, result = -1;
1.141 djm 221:
1.202 djm 222: gettimeofday(&t_start, NULL);
223:
224: if (*timeoutp <= 0) {
225: result = connect(sockfd, serv_addr, addrlen);
226: goto done;
227: }
1.141 djm 228:
1.156 djm 229: set_nonblock(sockfd);
1.141 djm 230: rc = connect(sockfd, serv_addr, addrlen);
1.156 djm 231: if (rc == 0) {
232: unset_nonblock(sockfd);
1.202 djm 233: result = 0;
234: goto done;
235: }
236: if (errno != EINPROGRESS) {
237: result = -1;
238: goto done;
1.156 djm 239: }
1.141 djm 240:
1.179 djm 241: fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
242: sizeof(fd_mask));
1.141 djm 243: FD_SET(sockfd, fdset);
1.202 djm 244: ms_to_timeval(&tv, *timeoutp);
1.141 djm 245:
1.162 deraadt 246: for (;;) {
1.141 djm 247: rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
248: if (rc != -1 || errno != EINTR)
249: break;
250: }
251:
1.162 deraadt 252: switch (rc) {
1.141 djm 253: case 0:
254: /* Timed out */
255: errno = ETIMEDOUT;
1.142 djm 256: break;
1.141 djm 257: case -1:
258: /* Select error */
1.154 djm 259: debug("select: %s", strerror(errno));
1.142 djm 260: break;
1.141 djm 261: case 1:
262: /* Completed or failed */
263: optval = 0;
264: optlen = sizeof(optval);
1.154 djm 265: if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
1.148 markus 266: &optlen) == -1) {
1.154 djm 267: debug("getsockopt: %s", strerror(errno));
1.142 djm 268: break;
1.148 markus 269: }
1.141 djm 270: if (optval != 0) {
271: errno = optval;
1.142 djm 272: break;
1.141 djm 273: }
1.142 djm 274: result = 0;
1.156 djm 275: unset_nonblock(sockfd);
1.141 djm 276: break;
277: default:
278: /* Should not occur */
279: fatal("Bogus return (%d) from select()", rc);
280: }
281:
1.142 djm 282: xfree(fdset);
1.202 djm 283:
284: done:
285: if (result == 0 && *timeoutp > 0) {
286: ms_subtract_diff(&t_start, timeoutp);
287: if (*timeoutp <= 0) {
288: errno = ETIMEDOUT;
289: result = -1;
290: }
291: }
292:
1.142 djm 293: return (result);
1.141 djm 294: }
295:
1.39 deraadt 296: /*
1.49 markus 297: * Opens a TCP/IP connection to the remote server on the given host.
298: * The address of the remote host will be returned in hostaddr.
1.124 markus 299: * If port is 0, the default port will be used. If needpriv is true,
1.39 deraadt 300: * a privileged port will be allocated to make the connection.
1.124 markus 301: * This requires super-user privileges if needpriv is true.
1.39 deraadt 302: * Connection_attempts specifies the maximum number of tries (one per
303: * second). If proxy_command is non-NULL, it specifies the command (with %h
304: * and %p substituted for host and port, respectively) to use to contact
305: * the daemon.
306: */
1.38 markus 307: int
1.49 markus 308: ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
1.202 djm 309: u_short port, int family, int connection_attempts, int *timeout_ms,
310: int want_keepalive, int needpriv, const char *proxy_command)
1.1 deraadt 311: {
1.90 markus 312: int gaierr;
313: int on = 1;
1.49 markus 314: int sock = -1, attempt;
1.90 markus 315: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.49 markus 316: struct addrinfo hints, *ai, *aitop;
1.38 markus 317:
1.136 markus 318: debug2("ssh_connect: needpriv %d", needpriv);
1.38 markus 319:
320: /* If a proxy command is given, connect using it. */
321: if (proxy_command != NULL)
1.124 markus 322: return ssh_proxy_connect(host, port, proxy_command);
1.38 markus 323:
324: /* No proxy command. */
325:
1.49 markus 326: memset(&hints, 0, sizeof(hints));
1.115 markus 327: hints.ai_family = family;
1.49 markus 328: hints.ai_socktype = SOCK_STREAM;
1.126 deraadt 329: snprintf(strport, sizeof strport, "%u", port);
1.49 markus 330: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
1.203 dtucker 331: fatal("%s: Could not resolve hostname %.100s: %s", __progname,
332: host, ssh_gai_strerror(gaierr));
1.38 markus 333:
1.181 markus 334: for (attempt = 0; attempt < connection_attempts; attempt++) {
1.200 markus 335: if (attempt > 0) {
336: /* Sleep a moment before retrying. */
337: sleep(1);
1.38 markus 338: debug("Trying again...");
1.200 markus 339: }
1.181 markus 340: /*
341: * Loop through addresses for this host, and try each one in
342: * sequence until the connection succeeds.
343: */
1.49 markus 344: for (ai = aitop; ai; ai = ai->ai_next) {
345: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
346: continue;
347: if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
348: ntop, sizeof(ntop), strport, sizeof(strport),
349: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
350: error("ssh_connect: getnameinfo failed");
351: continue;
352: }
353: debug("Connecting to %.200s [%.100s] port %s.",
354: host, ntop, strport);
355:
356: /* Create a socket for connecting. */
1.139 markus 357: sock = ssh_create_socket(needpriv, ai);
1.49 markus 358: if (sock < 0)
1.110 markus 359: /* Any error is already output */
1.49 markus 360: continue;
361:
1.141 djm 362: if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
1.202 djm 363: timeout_ms) >= 0) {
1.49 markus 364: /* Successful connection. */
1.102 markus 365: memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
1.38 markus 366: break;
1.49 markus 367: } else {
1.131 itojun 368: debug("connect to address %s port %s: %s",
369: ntop, strport, strerror(errno));
1.38 markus 370: close(sock);
1.181 markus 371: sock = -1;
1.38 markus 372: }
373: }
1.181 markus 374: if (sock != -1)
1.49 markus 375: break; /* Successful connection. */
1.38 markus 376: }
1.49 markus 377:
378: freeaddrinfo(aitop);
379:
1.38 markus 380: /* Return failure if we didn't get a successful connection. */
1.181 markus 381: if (sock == -1) {
1.159 markus 382: error("ssh: connect to host %s port %s: %s",
1.130 itojun 383: host, strport, strerror(errno));
1.159 markus 384: return (-1);
1.130 itojun 385: }
1.38 markus 386:
387: debug("Connection established.");
1.90 markus 388:
1.155 markus 389: /* Set SO_KEEPALIVE if requested. */
1.202 djm 390: if (want_keepalive &&
1.90 markus 391: setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
392: sizeof(on)) < 0)
393: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.38 markus 394:
395: /* Set the connection. */
396: packet_set_connection(sock, sock);
1.207 dtucker 397: packet_set_timeout(options.server_alive_interval,
398: options.server_alive_count_max);
1.1 deraadt 399:
1.110 markus 400: return 0;
1.59 markus 401: }
402:
1.43 markus 403: /*
1.39 deraadt 404: * Waits for the server identification string, and sends our own
405: * identification string.
406: */
1.109 itojun 407: static void
1.202 djm 408: ssh_exchange_identification(int timeout_ms)
1.1 deraadt 409: {
1.38 markus 410: char buf[256], remote_version[256]; /* must be same size! */
1.165 djm 411: int remote_major, remote_minor, mismatch;
1.38 markus 412: int connection_in = packet_get_connection_in();
413: int connection_out = packet_get_connection_out();
1.93 stevesk 414: int minor1 = PROTOCOL_MINOR_1;
1.185 djm 415: u_int i, n;
1.202 djm 416: size_t len;
417: int fdsetsz, remaining, rc;
418: struct timeval t_start, t_remaining;
419: fd_set *fdset;
420:
421: fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask);
422: fdset = xcalloc(1, fdsetsz);
1.38 markus 423:
1.163 avsm 424: /* Read other side's version identification. */
1.202 djm 425: remaining = timeout_ms;
1.185 djm 426: for (n = 0;;) {
1.75 markus 427: for (i = 0; i < sizeof(buf) - 1; i++) {
1.202 djm 428: if (timeout_ms > 0) {
429: gettimeofday(&t_start, NULL);
430: ms_to_timeval(&t_remaining, remaining);
431: FD_SET(connection_in, fdset);
432: rc = select(connection_in + 1, fdset, NULL,
433: fdset, &t_remaining);
434: ms_subtract_diff(&t_start, &remaining);
435: if (rc == 0 || remaining <= 0)
436: fatal("Connection timed out during "
437: "banner exchange");
438: if (rc == -1) {
439: if (errno == EINTR)
440: continue;
441: fatal("ssh_exchange_identification: "
442: "select: %s", strerror(errno));
443: }
444: }
445:
446: len = atomicio(read, connection_in, &buf[i], 1);
1.163 avsm 447:
1.167 djm 448: if (len != 1 && errno == EPIPE)
1.202 djm 449: fatal("ssh_exchange_identification: "
450: "Connection closed by remote host");
1.163 avsm 451: else if (len != 1)
1.202 djm 452: fatal("ssh_exchange_identification: "
453: "read: %.100s", strerror(errno));
1.75 markus 454: if (buf[i] == '\r') {
455: buf[i] = '\n';
456: buf[i + 1] = 0;
457: continue; /**XXX wait for \n */
458: }
459: if (buf[i] == '\n') {
460: buf[i + 1] = 0;
461: break;
462: }
1.185 djm 463: if (++n > 65536)
1.202 djm 464: fatal("ssh_exchange_identification: "
465: "No banner received");
1.38 markus 466: }
1.75 markus 467: buf[sizeof(buf) - 1] = 0;
1.76 markus 468: if (strncmp(buf, "SSH-", 4) == 0)
1.38 markus 469: break;
1.75 markus 470: debug("ssh_exchange_identification: %s", buf);
1.38 markus 471: }
1.59 markus 472: server_version_string = xstrdup(buf);
1.202 djm 473: xfree(fdset);
1.38 markus 474:
1.40 markus 475: /*
476: * Check that the versions match. In future this might accept
477: * several versions and set appropriate flags to handle them.
478: */
1.59 markus 479: if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
480: &remote_major, &remote_minor, remote_version) != 3)
1.38 markus 481: fatal("Bad remote protocol version identification: '%.100s'", buf);
482: debug("Remote protocol version %d.%d, remote software version %.100s",
1.118 deraadt 483: remote_major, remote_minor, remote_version);
1.38 markus 484:
1.59 markus 485: compat_datafellows(remote_version);
1.64 markus 486: mismatch = 0;
1.59 markus 487:
1.116 deraadt 488: switch (remote_major) {
1.64 markus 489: case 1:
490: if (remote_minor == 99 &&
491: (options.protocol & SSH_PROTO_2) &&
492: !(options.protocol & SSH_PROTO_1_PREFERRED)) {
493: enable_compat20();
494: break;
495: }
496: if (!(options.protocol & SSH_PROTO_1)) {
497: mismatch = 1;
498: break;
499: }
500: if (remote_minor < 3) {
501: fatal("Remote machine has too old SSH software version.");
1.81 markus 502: } else if (remote_minor == 3 || remote_minor == 4) {
1.64 markus 503: /* We speak 1.3, too. */
504: enable_compat13();
1.81 markus 505: minor1 = 3;
1.64 markus 506: if (options.forward_agent) {
1.138 itojun 507: logit("Agent forwarding disabled for protocol 1.3");
1.64 markus 508: options.forward_agent = 0;
509: }
510: }
511: break;
512: case 2:
513: if (options.protocol & SSH_PROTO_2) {
514: enable_compat20();
515: break;
1.38 markus 516: }
1.64 markus 517: /* FALLTHROUGH */
1.68 markus 518: default:
1.64 markus 519: mismatch = 1;
520: break;
1.38 markus 521: }
1.64 markus 522: if (mismatch)
1.38 markus 523: fatal("Protocol major versions differ: %d vs. %d",
1.64 markus 524: (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
525: remote_major);
1.38 markus 526: /* Send our own protocol version identification. */
527: snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
1.64 markus 528: compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
1.81 markus 529: compat20 ? PROTOCOL_MINOR_2 : minor1,
1.59 markus 530: SSH_VERSION);
1.146 deraadt 531: if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf))
1.38 markus 532: fatal("write: %.100s", strerror(errno));
1.59 markus 533: client_version_string = xstrdup(buf);
534: chop(client_version_string);
535: chop(server_version_string);
536: debug("Local version string %.100s", client_version_string);
1.1 deraadt 537: }
538:
1.96 markus 539: /* defaults to 'no' */
1.109 itojun 540: static int
1.112 markus 541: confirm(const char *prompt)
1.1 deraadt 542: {
1.119 markus 543: const char *msg, *again = "Please type 'yes' or 'no': ";
544: char *p;
545: int ret = -1;
1.96 markus 546:
547: if (options.batch_mode)
548: return 0;
1.119 markus 549: for (msg = prompt;;msg = again) {
550: p = read_passphrase(msg, RP_ECHO);
551: if (p == NULL ||
552: (p[0] == '\0') || (p[0] == '\n') ||
553: strncasecmp(p, "no", 2) == 0)
554: ret = 0;
1.127 markus 555: if (p && strncasecmp(p, "yes", 3) == 0)
1.119 markus 556: ret = 1;
557: if (p)
558: xfree(p);
559: if (ret != -1)
560: return ret;
1.1 deraadt 561: }
562: }
563:
1.39 deraadt 564: /*
1.108 markus 565: * check whether the supplied host key is valid, return -1 if the key
566: * is not valid. the user_hostfile will not be updated if 'readonly' is true.
1.39 deraadt 567: */
1.197 dtucker 568: #define RDRW 0
569: #define RDONLY 1
570: #define ROQUIET 2
1.109 itojun 571: static int
1.197 dtucker 572: check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
573: Key *host_key, int readonly, const char *user_hostfile,
574: const char *system_hostfile)
1.1 deraadt 575: {
1.58 markus 576: Key *file_key;
1.152 jakob 577: const char *type = key_type(host_key);
1.189 dtucker 578: char *ip = NULL, *host = NULL;
1.204 grunk 579: char hostline[1000], *hostp, *fp, *ra;
1.38 markus 580: HostStatus host_status;
581: HostStatus ip_status;
1.161 djm 582: int r, local = 0, host_ip_differ = 0;
1.49 markus 583: char ntop[NI_MAXHOST];
1.119 markus 584: char msg[1024];
1.210 ! dtucker 585: int len, host_line, ip_line, cancelled_forwarding = 0;
1.85 markus 586: const char *host_file = NULL, *ip_file = NULL;
1.49 markus 587:
588: /*
589: * Force accepting of the host key for loopback/localhost. The
590: * problem is that if the home directory is NFS-mounted to multiple
591: * machines, localhost will refer to a different machine in each of
592: * them, and the user will get bogus HOST_CHANGED warnings. This
593: * essentially disables host authentication for localhost; however,
594: * this is probably not a real problem.
595: */
1.70 markus 596: /** hostaddr == 0! */
1.49 markus 597: switch (hostaddr->sa_family) {
598: case AF_INET:
1.108 markus 599: local = (ntohl(((struct sockaddr_in *)hostaddr)->
1.168 djm 600: sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
1.49 markus 601: break;
602: case AF_INET6:
1.108 markus 603: local = IN6_IS_ADDR_LOOPBACK(
604: &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
1.49 markus 605: break;
606: default:
607: local = 0;
608: break;
609: }
1.111 markus 610: if (options.no_host_authentication_for_localhost == 1 && local &&
611: options.host_key_alias == NULL) {
1.88 markus 612: debug("Forcing accepting of host key for "
613: "loopback/localhost.");
1.108 markus 614: return 0;
1.49 markus 615: }
1.42 markus 616:
617: /*
1.88 markus 618: * We don't have the remote ip-address for connections
619: * using a proxy command
1.42 markus 620: */
1.84 markus 621: if (options.proxy_command == NULL) {
622: if (getnameinfo(hostaddr, hostaddr->sa_len, ntop, sizeof(ntop),
1.86 markus 623: NULL, 0, NI_NUMERICHOST) != 0)
1.84 markus 624: fatal("check_host_key: getnameinfo failed");
1.197 dtucker 625: ip = put_host_port(ntop, port);
1.84 markus 626: } else {
627: ip = xstrdup("<no hostip for proxy command>");
1.86 markus 628: }
1.206 grunk 629:
630: /*
1.88 markus 631: * Turn off check_host_ip if the connection is to localhost, via proxy
632: * command or if we don't have a hostname to compare with
633: */
1.189 dtucker 634: if (options.check_host_ip && (local ||
635: strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
1.88 markus 636: options.check_host_ip = 0;
1.86 markus 637:
638: /*
1.189 dtucker 639: * Allow the user to record the key under a different name or
640: * differentiate a non-standard port. This is useful for ssh
641: * tunneling over forwarded connections or if you run multiple
642: * sshd's on different ports on the same machine.
1.86 markus 643: */
644: if (options.host_key_alias != NULL) {
1.189 dtucker 645: host = xstrdup(options.host_key_alias);
1.86 markus 646: debug("using hostkeyalias: %s", host);
1.189 dtucker 647: } else {
1.197 dtucker 648: host = put_host_port(hostname, port);
1.84 markus 649: }
1.38 markus 650:
1.46 markus 651: /*
652: * Store the host key from the known host file in here so that we can
653: * compare it with the key for the IP address.
654: */
1.58 markus 655: file_key = key_new(host_key->type);
1.38 markus 656:
1.40 markus 657: /*
1.170 djm 658: * Check if the host key is present in the user's list of known
1.40 markus 659: * hosts or in the systemwide list.
660: */
1.85 markus 661: host_file = user_hostfile;
1.108 markus 662: host_status = check_host_in_hostfile(host_file, host, host_key,
1.118 deraadt 663: file_key, &host_line);
1.85 markus 664: if (host_status == HOST_NEW) {
665: host_file = system_hostfile;
1.108 markus 666: host_status = check_host_in_hostfile(host_file, host, host_key,
667: file_key, &host_line);
1.85 markus 668: }
1.40 markus 669: /*
670: * Also perform check for the ip address, skip the check if we are
671: * localhost or the hostname was an ip address to begin with
672: */
1.88 markus 673: if (options.check_host_ip) {
1.58 markus 674: Key *ip_key = key_new(host_key->type);
1.38 markus 675:
1.85 markus 676: ip_file = user_hostfile;
1.108 markus 677: ip_status = check_host_in_hostfile(ip_file, ip, host_key,
678: ip_key, &ip_line);
1.85 markus 679: if (ip_status == HOST_NEW) {
680: ip_file = system_hostfile;
1.108 markus 681: ip_status = check_host_in_hostfile(ip_file, ip,
682: host_key, ip_key, &ip_line);
1.85 markus 683: }
1.38 markus 684: if (host_status == HOST_CHANGED &&
1.58 markus 685: (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
1.38 markus 686: host_ip_differ = 1;
687:
1.58 markus 688: key_free(ip_key);
1.38 markus 689: } else
690: ip_status = host_status;
691:
1.58 markus 692: key_free(file_key);
1.38 markus 693:
694: switch (host_status) {
695: case HOST_OK:
696: /* The host is known and the key matches. */
1.72 markus 697: debug("Host '%.200s' is known and matches the %s host key.",
698: host, type);
1.85 markus 699: debug("Found key in %s:%d", host_file, host_line);
1.88 markus 700: if (options.check_host_ip && ip_status == HOST_NEW) {
1.108 markus 701: if (readonly)
1.138 itojun 702: logit("%s host key for IP address "
1.108 markus 703: "'%.128s' not in list of known hosts.",
704: type, ip);
705: else if (!add_host_to_hostfile(user_hostfile, ip,
1.160 djm 706: host_key, options.hash_known_hosts))
1.138 itojun 707: logit("Failed to add the %s host key for IP "
1.108 markus 708: "address '%.128s' to the list of known "
709: "hosts (%.30s).", type, ip, user_hostfile);
1.88 markus 710: else
1.138 itojun 711: logit("Warning: Permanently added the %s host "
1.108 markus 712: "key for IP address '%.128s' to the list "
713: "of known hosts.", type, ip);
1.209 grunk 714: } else if (options.visual_host_key) {
1.204 grunk 715: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
716: ra = key_fingerprint(host_key, SSH_FP_MD5,
717: SSH_FP_RANDOMART);
718: logit("Host key fingerprint is %s\n%s\n", fp, ra);
719: xfree(ra);
720: xfree(fp);
1.38 markus 721: }
722: break;
723: case HOST_NEW:
1.197 dtucker 724: if (options.host_key_alias == NULL && port != 0 &&
725: port != SSH_DEFAULT_PORT) {
726: debug("checking without port identifier");
727: if (check_host_key(hostname, hostaddr, 0, host_key, 2,
728: user_hostfile, system_hostfile) == 0) {
729: debug("found matching key w/out port");
730: break;
731: }
732: }
1.108 markus 733: if (readonly)
734: goto fail;
1.38 markus 735: /* The host is new. */
736: if (options.strict_host_key_checking == 1) {
1.108 markus 737: /*
738: * User has requested strict host key checking. We
739: * will not add the host key automatically. The only
740: * alternative left is to abort.
741: */
742: error("No %s host key is known for %.200s and you "
743: "have requested strict checking.", type, host);
744: goto fail;
1.38 markus 745: } else if (options.strict_host_key_checking == 2) {
1.145 jakob 746: char msg1[1024], msg2[1024];
747:
748: if (show_other_keys(host, host_key))
749: snprintf(msg1, sizeof(msg1),
1.168 djm 750: "\nbut keys of different type are already"
751: " known for this host.");
1.145 jakob 752: else
753: snprintf(msg1, sizeof(msg1), ".");
1.38 markus 754: /* The default */
1.100 markus 755: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 756: ra = key_fingerprint(host_key, SSH_FP_MD5,
757: SSH_FP_RANDOMART);
1.145 jakob 758: msg2[0] = '\0';
759: if (options.verify_host_key_dns) {
1.153 jakob 760: if (matching_host_key_dns)
1.145 jakob 761: snprintf(msg2, sizeof(msg2),
762: "Matching host key fingerprint"
763: " found in DNS.\n");
764: else
765: snprintf(msg2, sizeof(msg2),
766: "No matching host key fingerprint"
767: " found in DNS.\n");
768: }
1.119 markus 769: snprintf(msg, sizeof(msg),
1.108 markus 770: "The authenticity of host '%.200s (%s)' can't be "
1.132 markus 771: "established%s\n"
1.209 grunk 772: "%s key fingerprint is %s.%s%s\n%s"
1.108 markus 773: "Are you sure you want to continue connecting "
1.132 markus 774: "(yes/no)? ",
1.209 grunk 775: host, ip, msg1, type, fp,
776: options.visual_host_key ? "\n" : "",
777: options.visual_host_key ? ra : "",
778: msg2);
1.204 grunk 779: xfree(ra);
1.100 markus 780: xfree(fp);
1.119 markus 781: if (!confirm(msg))
1.108 markus 782: goto fail;
1.38 markus 783: }
1.161 djm 784: /*
785: * If not in strict mode, add the key automatically to the
786: * local known_hosts file.
787: */
1.88 markus 788: if (options.check_host_ip && ip_status == HOST_NEW) {
1.161 djm 789: snprintf(hostline, sizeof(hostline), "%s,%s",
790: host, ip);
1.38 markus 791: hostp = hostline;
1.161 djm 792: if (options.hash_known_hosts) {
793: /* Add hash of host and IP separately */
794: r = add_host_to_hostfile(user_hostfile, host,
795: host_key, options.hash_known_hosts) &&
796: add_host_to_hostfile(user_hostfile, ip,
797: host_key, options.hash_known_hosts);
798: } else {
799: /* Add unhashed "host,ip" */
800: r = add_host_to_hostfile(user_hostfile,
801: hostline, host_key,
802: options.hash_known_hosts);
803: }
804: } else {
805: r = add_host_to_hostfile(user_hostfile, host, host_key,
806: options.hash_known_hosts);
1.38 markus 807: hostp = host;
1.161 djm 808: }
1.38 markus 809:
1.161 djm 810: if (!r)
1.138 itojun 811: logit("Failed to add the host to the list of known "
1.108 markus 812: "hosts (%.500s).", user_hostfile);
1.38 markus 813: else
1.138 itojun 814: logit("Warning: Permanently added '%.200s' (%s) to the "
1.108 markus 815: "list of known hosts.", hostp, type);
1.38 markus 816: break;
817: case HOST_CHANGED:
1.197 dtucker 818: if (readonly == ROQUIET)
819: goto fail;
1.38 markus 820: if (options.check_host_ip && host_ip_differ) {
1.158 avsm 821: char *key_msg;
1.38 markus 822: if (ip_status == HOST_NEW)
1.158 avsm 823: key_msg = "is unknown";
1.38 markus 824: else if (ip_status == HOST_OK)
1.158 avsm 825: key_msg = "is unchanged";
1.38 markus 826: else
1.158 avsm 827: key_msg = "has a different value";
1.38 markus 828: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
829: error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
830: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1.72 markus 831: error("The %s host key for %s has changed,", type, host);
1.208 ian 832: error("and the key for the corresponding IP address %s", ip);
1.158 avsm 833: error("%s. This could either mean that", key_msg);
1.38 markus 834: error("DNS SPOOFING is happening or the IP address for the host");
1.85 markus 835: error("and its host key have changed at the same time.");
1.88 markus 836: if (ip_status != HOST_NEW)
1.85 markus 837: error("Offending key for IP in %s:%d", ip_file, ip_line);
1.38 markus 838: }
839: /* The host key has changed. */
1.150 jakob 840: warn_changed_key(host_key);
1.38 markus 841: error("Add correct host key in %.100s to get rid of this message.",
1.87 markus 842: user_hostfile);
1.85 markus 843: error("Offending key in %s:%d", host_file, host_line);
1.38 markus 844:
1.40 markus 845: /*
846: * If strict host key checking is in use, the user will have
847: * to edit the key manually and we can only abort.
848: */
1.108 markus 849: if (options.strict_host_key_checking) {
850: error("%s host key for %.200s has changed and you have "
851: "requested strict checking.", type, host);
852: goto fail;
853: }
1.38 markus 854:
1.40 markus 855: /*
856: * If strict host key checking has not been requested, allow
1.144 djm 857: * the connection but without MITM-able authentication or
1.194 stevesk 858: * forwarding.
1.40 markus 859: */
1.38 markus 860: if (options.password_authentication) {
1.108 markus 861: error("Password authentication is disabled to avoid "
862: "man-in-the-middle attacks.");
1.38 markus 863: options.password_authentication = 0;
1.210 ! dtucker 864: cancelled_forwarding = 1;
1.144 djm 865: }
866: if (options.kbd_interactive_authentication) {
867: error("Keyboard-interactive authentication is disabled"
868: " to avoid man-in-the-middle attacks.");
869: options.kbd_interactive_authentication = 0;
870: options.challenge_response_authentication = 0;
1.210 ! dtucker 871: cancelled_forwarding = 1;
1.144 djm 872: }
873: if (options.challenge_response_authentication) {
874: error("Challenge/response authentication is disabled"
875: " to avoid man-in-the-middle attacks.");
876: options.challenge_response_authentication = 0;
1.210 ! dtucker 877: cancelled_forwarding = 1;
1.38 markus 878: }
879: if (options.forward_agent) {
1.108 markus 880: error("Agent forwarding is disabled to avoid "
881: "man-in-the-middle attacks.");
1.38 markus 882: options.forward_agent = 0;
1.210 ! dtucker 883: cancelled_forwarding = 1;
1.83 markus 884: }
885: if (options.forward_x11) {
1.108 markus 886: error("X11 forwarding is disabled to avoid "
887: "man-in-the-middle attacks.");
1.83 markus 888: options.forward_x11 = 0;
1.210 ! dtucker 889: cancelled_forwarding = 1;
1.83 markus 890: }
1.108 markus 891: if (options.num_local_forwards > 0 ||
892: options.num_remote_forwards > 0) {
893: error("Port forwarding is disabled to avoid "
894: "man-in-the-middle attacks.");
895: options.num_local_forwards =
1.118 deraadt 896: options.num_remote_forwards = 0;
1.210 ! dtucker 897: cancelled_forwarding = 1;
1.194 stevesk 898: }
899: if (options.tun_open != SSH_TUNMODE_NO) {
900: error("Tunnel forwarding is disabled to avoid "
901: "man-in-the-middle attacks.");
902: options.tun_open = SSH_TUNMODE_NO;
1.210 ! dtucker 903: cancelled_forwarding = 1;
1.38 markus 904: }
1.210 ! dtucker 905: if (options.exit_on_forward_failure && cancelled_forwarding)
! 906: fatal("Error: forwarding disabled due to host key "
! 907: "check failure");
! 908:
1.40 markus 909: /*
910: * XXX Should permit the user to change to use the new id.
911: * This could be done by converting the host key to an
912: * identifying sentence, tell that the host identifies itself
913: * by that sentence, and ask the user if he/she whishes to
914: * accept the authentication.
915: */
1.38 markus 916: break;
1.132 markus 917: case HOST_FOUND:
918: fatal("internal error");
919: break;
1.88 markus 920: }
921:
922: if (options.check_host_ip && host_status != HOST_CHANGED &&
923: ip_status == HOST_CHANGED) {
1.119 markus 924: snprintf(msg, sizeof(msg),
925: "Warning: the %s host key for '%.200s' "
926: "differs from the key for the IP address '%.128s'"
927: "\nOffending key for IP in %s:%d",
928: type, host, ip, ip_file, ip_line);
929: if (host_status == HOST_OK) {
930: len = strlen(msg);
931: snprintf(msg + len, sizeof(msg) - len,
932: "\nMatching host key in %s:%d",
1.125 deraadt 933: host_file, host_line);
1.119 markus 934: }
1.88 markus 935: if (options.strict_host_key_checking == 1) {
1.143 djm 936: logit("%s", msg);
1.108 markus 937: error("Exiting, you have requested strict checking.");
938: goto fail;
1.88 markus 939: } else if (options.strict_host_key_checking == 2) {
1.119 markus 940: strlcat(msg, "\nAre you sure you want "
941: "to continue connecting (yes/no)? ", sizeof(msg));
942: if (!confirm(msg))
1.108 markus 943: goto fail;
1.119 markus 944: } else {
1.143 djm 945: logit("%s", msg);
1.88 markus 946: }
1.38 markus 947: }
1.82 provos 948:
949: xfree(ip);
1.189 dtucker 950: xfree(host);
1.108 markus 951: return 0;
952:
953: fail:
954: xfree(ip);
1.189 dtucker 955: xfree(host);
1.108 markus 956: return -1;
957: }
958:
1.140 jakob 959: /* returns 0 if key verifies or -1 if key does NOT verify */
1.108 markus 960: int
961: verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
962: {
963: struct stat st;
1.153 jakob 964: int flags = 0;
1.140 jakob 965:
1.153 jakob 966: if (options.verify_host_key_dns &&
967: verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
968:
969: if (flags & DNS_VERIFY_FOUND) {
970:
971: if (options.verify_host_key_dns == 1 &&
972: flags & DNS_VERIFY_MATCH &&
973: flags & DNS_VERIFY_SECURE)
974: return 0;
975:
976: if (flags & DNS_VERIFY_MATCH) {
977: matching_host_key_dns = 1;
978: } else {
979: warn_changed_key(host_key);
980: error("Update the SSHFP RR in DNS with the new "
981: "host key to get rid of this message.");
982: }
1.140 jakob 983: }
984: }
1.108 markus 985:
986: /* return ok if the key can be found in an old keyfile */
987: if (stat(options.system_hostfile2, &st) == 0 ||
988: stat(options.user_hostfile2, &st) == 0) {
1.197 dtucker 989: if (check_host_key(host, hostaddr, options.port, host_key,
990: RDONLY, options.user_hostfile2,
991: options.system_hostfile2) == 0)
1.108 markus 992: return 0;
993: }
1.197 dtucker 994: return check_host_key(host, hostaddr, options.port, host_key,
995: RDRW, options.user_hostfile, options.system_hostfile);
1.51 markus 996: }
1.70 markus 997:
1.51 markus 998: /*
999: * Starts a dialog with the server, and authenticates the current user on the
1000: * server. This does not need any extra privileges. The basic connection
1001: * to the server must already have been established before this is called.
1002: * If login fails, this function prints an error and never returns.
1003: * This function does not require super-user privileges.
1004: */
1005: void
1.120 markus 1006: ssh_login(Sensitive *sensitive, const char *orighost,
1.202 djm 1007: struct sockaddr *hostaddr, struct passwd *pw, int timeout_ms)
1.51 markus 1008: {
1009: char *host, *cp;
1.70 markus 1010: char *server_user, *local_user;
1011:
1012: local_user = xstrdup(pw->pw_name);
1013: server_user = options.user ? options.user : local_user;
1.51 markus 1014:
1015: /* Convert the user-supplied hostname into all lowercase. */
1016: host = xstrdup(orighost);
1017: for (cp = host; *cp; cp++)
1018: if (isupper(*cp))
1.178 deraadt 1019: *cp = (char)tolower(*cp);
1.51 markus 1020:
1021: /* Exchange protocol version identification strings with the server. */
1.202 djm 1022: ssh_exchange_identification(timeout_ms);
1.51 markus 1023:
1024: /* Put the connection into non-blocking mode. */
1025: packet_set_nonblocking();
1026:
1027: /* key exchange */
1028: /* authenticate user */
1.59 markus 1029: if (compat20) {
1030: ssh_kex2(host, hostaddr);
1.120 markus 1031: ssh_userauth2(local_user, server_user, host, sensitive);
1.59 markus 1032: } else {
1033: ssh_kex(host, hostaddr);
1.120 markus 1034: ssh_userauth1(local_user, server_user, host, sensitive);
1.59 markus 1035: }
1.182 markus 1036: xfree(local_user);
1.97 markus 1037: }
1038:
1039: void
1040: ssh_put_password(char *password)
1041: {
1042: int size;
1043: char *padded;
1044:
1.99 deraadt 1045: if (datafellows & SSH_BUG_PASSWORDPAD) {
1.107 markus 1046: packet_put_cstring(password);
1.99 deraadt 1047: return;
1048: }
1.97 markus 1049: size = roundup(strlen(password) + 1, 32);
1.179 djm 1050: padded = xcalloc(1, size);
1.97 markus 1051: strlcpy(padded, password, size);
1052: packet_put_string(padded, size);
1053: memset(padded, 0, size);
1054: xfree(padded);
1.132 markus 1055: }
1056:
1057: static int
1058: show_key_from_file(const char *file, const char *host, int keytype)
1059: {
1060: Key *found;
1.204 grunk 1061: char *fp, *ra;
1.132 markus 1062: int line, ret;
1063:
1064: found = key_new(keytype);
1065: if ((ret = lookup_key_in_hostfile_by_type(file, host,
1066: keytype, found, &line))) {
1067: fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 1068: ra = key_fingerprint(found, SSH_FP_MD5, SSH_FP_RANDOMART);
1.138 itojun 1069: logit("WARNING: %s key found for host %s\n"
1.133 markus 1070: "in %s:%d\n"
1.204 grunk 1071: "%s key fingerprint %s.\n%s\n",
1.132 markus 1072: key_type(found), host, file, line,
1.204 grunk 1073: key_type(found), fp, ra);
1074: xfree(ra);
1.132 markus 1075: xfree(fp);
1076: }
1077: key_free(found);
1078: return (ret);
1079: }
1080:
1081: /* print all known host keys for a given host, but skip keys of given type */
1082: static int
1083: show_other_keys(const char *host, Key *key)
1084: {
1085: int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1};
1086: int i, found = 0;
1087:
1088: for (i = 0; type[i] != -1; i++) {
1089: if (type[i] == key->type)
1090: continue;
1091: if (type[i] != KEY_RSA1 &&
1092: show_key_from_file(options.user_hostfile2, host, type[i])) {
1093: found = 1;
1094: continue;
1095: }
1096: if (type[i] != KEY_RSA1 &&
1097: show_key_from_file(options.system_hostfile2, host, type[i])) {
1098: found = 1;
1099: continue;
1100: }
1101: if (show_key_from_file(options.user_hostfile, host, type[i])) {
1102: found = 1;
1103: continue;
1104: }
1105: if (show_key_from_file(options.system_hostfile, host, type[i])) {
1106: found = 1;
1107: continue;
1108: }
1109: debug2("no key of type %d for host %s", type[i], host);
1110: }
1111: return (found);
1.150 jakob 1112: }
1113:
1114: static void
1115: warn_changed_key(Key *host_key)
1116: {
1117: char *fp;
1.151 jakob 1118: const char *type = key_type(host_key);
1.150 jakob 1119:
1120: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1121:
1122: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1123: error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1124: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1125: error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1126: error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1127: error("It is also possible that the %s host key has just been changed.", type);
1128: error("The fingerprint for the %s key sent by the remote host is\n%s.",
1129: type, fp);
1130: error("Please contact your system administrator.");
1131:
1132: xfree(fp);
1.171 reyk 1133: }
1134:
1135: /*
1136: * Execute a local command
1137: */
1138: int
1139: ssh_local_cmd(const char *args)
1140: {
1141: char *shell;
1142: pid_t pid;
1143: int status;
1144:
1145: if (!options.permit_local_command ||
1146: args == NULL || !*args)
1147: return (1);
1148:
1149: if ((shell = getenv("SHELL")) == NULL)
1150: shell = _PATH_BSHELL;
1151:
1152: pid = fork();
1153: if (pid == 0) {
1154: debug3("Executing %s -c \"%s\"", shell, args);
1155: execl(shell, shell, "-c", args, (char *)NULL);
1156: error("Couldn't execute %s -c \"%s\": %s",
1157: shell, args, strerror(errno));
1158: _exit(1);
1159: } else if (pid == -1)
1160: fatal("fork failed: %.100s", strerror(errno));
1161: while (waitpid(pid, &status, 0) == -1)
1162: if (errno != EINTR)
1163: fatal("Couldn't wait for child: %s", strerror(errno));
1164:
1165: if (!WIFEXITED(status))
1166: return (1);
1167:
1168: return (WEXITSTATUS(status));
1.1 deraadt 1169: }
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