Annotation of src/usr.bin/ssh/sshconnect.c, Revision 1.216
1.216 ! dtucker 1: /* $OpenBSD: sshconnect.c,v 1.215 2009/10/28 16:38:18 reyk 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: }
1.215 reyk 185: sock = socket_rdomain(ai->ai_family, ai->ai_socktype, ai->ai_protocol,
186: options.rdomain);
1.216 ! dtucker 187: if (sock < 0) {
1.105 markus 188: error("socket: %.100s", strerror(errno));
1.216 ! dtucker 189: return -1;
! 190: }
! 191: fcntl(sock, F_SETFD, FD_CLOEXEC);
1.105 markus 192:
193: /* Bind the socket to an alternative local IP address */
194: if (options.bind_address == NULL)
195: return sock;
196:
197: memset(&hints, 0, sizeof(hints));
1.139 markus 198: hints.ai_family = ai->ai_family;
199: hints.ai_socktype = ai->ai_socktype;
200: hints.ai_protocol = ai->ai_protocol;
1.105 markus 201: hints.ai_flags = AI_PASSIVE;
1.205 dtucker 202: gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res);
1.105 markus 203: if (gaierr) {
204: error("getaddrinfo: %s: %s", options.bind_address,
1.203 dtucker 205: ssh_gai_strerror(gaierr));
1.105 markus 206: close(sock);
207: return -1;
208: }
209: if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
210: error("bind: %s: %s", options.bind_address, strerror(errno));
211: close(sock);
212: freeaddrinfo(res);
213: return -1;
1.38 markus 214: }
1.105 markus 215: freeaddrinfo(res);
1.38 markus 216: return sock;
1.1 deraadt 217: }
218:
1.141 djm 219: static int
220: timeout_connect(int sockfd, const struct sockaddr *serv_addr,
1.202 djm 221: socklen_t addrlen, int *timeoutp)
1.141 djm 222: {
223: fd_set *fdset;
1.202 djm 224: struct timeval tv, t_start;
1.141 djm 225: socklen_t optlen;
1.179 djm 226: int optval, rc, result = -1;
1.141 djm 227:
1.202 djm 228: gettimeofday(&t_start, NULL);
229:
230: if (*timeoutp <= 0) {
231: result = connect(sockfd, serv_addr, addrlen);
232: goto done;
233: }
1.141 djm 234:
1.156 djm 235: set_nonblock(sockfd);
1.141 djm 236: rc = connect(sockfd, serv_addr, addrlen);
1.156 djm 237: if (rc == 0) {
238: unset_nonblock(sockfd);
1.202 djm 239: result = 0;
240: goto done;
241: }
242: if (errno != EINPROGRESS) {
243: result = -1;
244: goto done;
1.156 djm 245: }
1.141 djm 246:
1.179 djm 247: fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
248: sizeof(fd_mask));
1.141 djm 249: FD_SET(sockfd, fdset);
1.202 djm 250: ms_to_timeval(&tv, *timeoutp);
1.141 djm 251:
1.162 deraadt 252: for (;;) {
1.141 djm 253: rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
254: if (rc != -1 || errno != EINTR)
255: break;
256: }
257:
1.162 deraadt 258: switch (rc) {
1.141 djm 259: case 0:
260: /* Timed out */
261: errno = ETIMEDOUT;
1.142 djm 262: break;
1.141 djm 263: case -1:
264: /* Select error */
1.154 djm 265: debug("select: %s", strerror(errno));
1.142 djm 266: break;
1.141 djm 267: case 1:
268: /* Completed or failed */
269: optval = 0;
270: optlen = sizeof(optval);
1.154 djm 271: if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
1.148 markus 272: &optlen) == -1) {
1.154 djm 273: debug("getsockopt: %s", strerror(errno));
1.142 djm 274: break;
1.148 markus 275: }
1.141 djm 276: if (optval != 0) {
277: errno = optval;
1.142 djm 278: break;
1.141 djm 279: }
1.142 djm 280: result = 0;
1.156 djm 281: unset_nonblock(sockfd);
1.141 djm 282: break;
283: default:
284: /* Should not occur */
285: fatal("Bogus return (%d) from select()", rc);
286: }
287:
1.142 djm 288: xfree(fdset);
1.202 djm 289:
290: done:
291: if (result == 0 && *timeoutp > 0) {
292: ms_subtract_diff(&t_start, timeoutp);
293: if (*timeoutp <= 0) {
294: errno = ETIMEDOUT;
295: result = -1;
296: }
297: }
298:
1.142 djm 299: return (result);
1.141 djm 300: }
301:
1.39 deraadt 302: /*
1.49 markus 303: * Opens a TCP/IP connection to the remote server on the given host.
304: * The address of the remote host will be returned in hostaddr.
1.124 markus 305: * If port is 0, the default port will be used. If needpriv is true,
1.39 deraadt 306: * a privileged port will be allocated to make the connection.
1.124 markus 307: * This requires super-user privileges if needpriv is true.
1.39 deraadt 308: * Connection_attempts specifies the maximum number of tries (one per
309: * second). If proxy_command is non-NULL, it specifies the command (with %h
310: * and %p substituted for host and port, respectively) to use to contact
311: * the daemon.
312: */
1.38 markus 313: int
1.49 markus 314: ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
1.202 djm 315: u_short port, int family, int connection_attempts, int *timeout_ms,
316: int want_keepalive, int needpriv, const char *proxy_command)
1.1 deraadt 317: {
1.90 markus 318: int gaierr;
319: int on = 1;
1.49 markus 320: int sock = -1, attempt;
1.90 markus 321: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.49 markus 322: struct addrinfo hints, *ai, *aitop;
1.38 markus 323:
1.136 markus 324: debug2("ssh_connect: needpriv %d", needpriv);
1.38 markus 325:
326: /* If a proxy command is given, connect using it. */
327: if (proxy_command != NULL)
1.124 markus 328: return ssh_proxy_connect(host, port, proxy_command);
1.38 markus 329:
330: /* No proxy command. */
331:
1.49 markus 332: memset(&hints, 0, sizeof(hints));
1.115 markus 333: hints.ai_family = family;
1.49 markus 334: hints.ai_socktype = SOCK_STREAM;
1.126 deraadt 335: snprintf(strport, sizeof strport, "%u", port);
1.49 markus 336: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
1.203 dtucker 337: fatal("%s: Could not resolve hostname %.100s: %s", __progname,
338: host, ssh_gai_strerror(gaierr));
1.38 markus 339:
1.181 markus 340: for (attempt = 0; attempt < connection_attempts; attempt++) {
1.200 markus 341: if (attempt > 0) {
342: /* Sleep a moment before retrying. */
343: sleep(1);
1.38 markus 344: debug("Trying again...");
1.200 markus 345: }
1.181 markus 346: /*
347: * Loop through addresses for this host, and try each one in
348: * sequence until the connection succeeds.
349: */
1.49 markus 350: for (ai = aitop; ai; ai = ai->ai_next) {
351: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
352: continue;
353: if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
354: ntop, sizeof(ntop), strport, sizeof(strport),
355: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
356: error("ssh_connect: getnameinfo failed");
357: continue;
358: }
359: debug("Connecting to %.200s [%.100s] port %s.",
360: host, ntop, strport);
361:
362: /* Create a socket for connecting. */
1.139 markus 363: sock = ssh_create_socket(needpriv, ai);
1.49 markus 364: if (sock < 0)
1.110 markus 365: /* Any error is already output */
1.49 markus 366: continue;
367:
1.141 djm 368: if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
1.202 djm 369: timeout_ms) >= 0) {
1.49 markus 370: /* Successful connection. */
1.102 markus 371: memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
1.38 markus 372: break;
1.49 markus 373: } else {
1.131 itojun 374: debug("connect to address %s port %s: %s",
375: ntop, strport, strerror(errno));
1.38 markus 376: close(sock);
1.181 markus 377: sock = -1;
1.38 markus 378: }
379: }
1.181 markus 380: if (sock != -1)
1.49 markus 381: break; /* Successful connection. */
1.38 markus 382: }
1.49 markus 383:
384: freeaddrinfo(aitop);
385:
1.38 markus 386: /* Return failure if we didn't get a successful connection. */
1.181 markus 387: if (sock == -1) {
1.159 markus 388: error("ssh: connect to host %s port %s: %s",
1.130 itojun 389: host, strport, strerror(errno));
1.159 markus 390: return (-1);
1.130 itojun 391: }
1.38 markus 392:
393: debug("Connection established.");
1.90 markus 394:
1.155 markus 395: /* Set SO_KEEPALIVE if requested. */
1.202 djm 396: if (want_keepalive &&
1.90 markus 397: setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
398: sizeof(on)) < 0)
399: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.38 markus 400:
401: /* Set the connection. */
402: packet_set_connection(sock, sock);
1.207 dtucker 403: packet_set_timeout(options.server_alive_interval,
404: options.server_alive_count_max);
1.1 deraadt 405:
1.110 markus 406: return 0;
1.59 markus 407: }
408:
1.43 markus 409: /*
1.39 deraadt 410: * Waits for the server identification string, and sends our own
411: * identification string.
412: */
1.213 andreas 413: void
1.202 djm 414: ssh_exchange_identification(int timeout_ms)
1.1 deraadt 415: {
1.38 markus 416: char buf[256], remote_version[256]; /* must be same size! */
1.165 djm 417: int remote_major, remote_minor, mismatch;
1.38 markus 418: int connection_in = packet_get_connection_in();
419: int connection_out = packet_get_connection_out();
1.93 stevesk 420: int minor1 = PROTOCOL_MINOR_1;
1.185 djm 421: u_int i, n;
1.202 djm 422: size_t len;
423: int fdsetsz, remaining, rc;
424: struct timeval t_start, t_remaining;
425: fd_set *fdset;
426:
427: fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask);
428: fdset = xcalloc(1, fdsetsz);
1.38 markus 429:
1.163 avsm 430: /* Read other side's version identification. */
1.202 djm 431: remaining = timeout_ms;
1.185 djm 432: for (n = 0;;) {
1.75 markus 433: for (i = 0; i < sizeof(buf) - 1; i++) {
1.202 djm 434: if (timeout_ms > 0) {
435: gettimeofday(&t_start, NULL);
436: ms_to_timeval(&t_remaining, remaining);
437: FD_SET(connection_in, fdset);
438: rc = select(connection_in + 1, fdset, NULL,
439: fdset, &t_remaining);
440: ms_subtract_diff(&t_start, &remaining);
441: if (rc == 0 || remaining <= 0)
442: fatal("Connection timed out during "
443: "banner exchange");
444: if (rc == -1) {
445: if (errno == EINTR)
446: continue;
447: fatal("ssh_exchange_identification: "
448: "select: %s", strerror(errno));
449: }
450: }
451:
1.214 andreas 452: len = roaming_atomicio(read, connection_in, &buf[i], 1);
1.163 avsm 453:
1.167 djm 454: if (len != 1 && errno == EPIPE)
1.202 djm 455: fatal("ssh_exchange_identification: "
456: "Connection closed by remote host");
1.163 avsm 457: else if (len != 1)
1.202 djm 458: fatal("ssh_exchange_identification: "
459: "read: %.100s", strerror(errno));
1.75 markus 460: if (buf[i] == '\r') {
461: buf[i] = '\n';
462: buf[i + 1] = 0;
463: continue; /**XXX wait for \n */
464: }
465: if (buf[i] == '\n') {
466: buf[i + 1] = 0;
467: break;
468: }
1.185 djm 469: if (++n > 65536)
1.202 djm 470: fatal("ssh_exchange_identification: "
471: "No banner received");
1.38 markus 472: }
1.75 markus 473: buf[sizeof(buf) - 1] = 0;
1.76 markus 474: if (strncmp(buf, "SSH-", 4) == 0)
1.38 markus 475: break;
1.75 markus 476: debug("ssh_exchange_identification: %s", buf);
1.38 markus 477: }
1.59 markus 478: server_version_string = xstrdup(buf);
1.202 djm 479: xfree(fdset);
1.38 markus 480:
1.40 markus 481: /*
482: * Check that the versions match. In future this might accept
483: * several versions and set appropriate flags to handle them.
484: */
1.59 markus 485: if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
486: &remote_major, &remote_minor, remote_version) != 3)
1.38 markus 487: fatal("Bad remote protocol version identification: '%.100s'", buf);
488: debug("Remote protocol version %d.%d, remote software version %.100s",
1.118 deraadt 489: remote_major, remote_minor, remote_version);
1.38 markus 490:
1.59 markus 491: compat_datafellows(remote_version);
1.64 markus 492: mismatch = 0;
1.59 markus 493:
1.116 deraadt 494: switch (remote_major) {
1.64 markus 495: case 1:
496: if (remote_minor == 99 &&
497: (options.protocol & SSH_PROTO_2) &&
498: !(options.protocol & SSH_PROTO_1_PREFERRED)) {
499: enable_compat20();
500: break;
501: }
502: if (!(options.protocol & SSH_PROTO_1)) {
503: mismatch = 1;
504: break;
505: }
506: if (remote_minor < 3) {
507: fatal("Remote machine has too old SSH software version.");
1.81 markus 508: } else if (remote_minor == 3 || remote_minor == 4) {
1.64 markus 509: /* We speak 1.3, too. */
510: enable_compat13();
1.81 markus 511: minor1 = 3;
1.64 markus 512: if (options.forward_agent) {
1.138 itojun 513: logit("Agent forwarding disabled for protocol 1.3");
1.64 markus 514: options.forward_agent = 0;
515: }
516: }
517: break;
518: case 2:
519: if (options.protocol & SSH_PROTO_2) {
520: enable_compat20();
521: break;
1.38 markus 522: }
1.64 markus 523: /* FALLTHROUGH */
1.68 markus 524: default:
1.64 markus 525: mismatch = 1;
526: break;
1.38 markus 527: }
1.64 markus 528: if (mismatch)
1.38 markus 529: fatal("Protocol major versions differ: %d vs. %d",
1.64 markus 530: (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
531: remote_major);
1.38 markus 532: /* Send our own protocol version identification. */
1.211 dtucker 533: snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s%s",
1.64 markus 534: compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
1.81 markus 535: compat20 ? PROTOCOL_MINOR_2 : minor1,
1.211 dtucker 536: SSH_VERSION, compat20 ? "\r\n" : "\n");
1.214 andreas 537: if (roaming_atomicio(vwrite, connection_out, buf, strlen(buf))
538: != strlen(buf))
1.38 markus 539: fatal("write: %.100s", strerror(errno));
1.59 markus 540: client_version_string = xstrdup(buf);
541: chop(client_version_string);
542: chop(server_version_string);
543: debug("Local version string %.100s", client_version_string);
1.1 deraadt 544: }
545:
1.96 markus 546: /* defaults to 'no' */
1.109 itojun 547: static int
1.112 markus 548: confirm(const char *prompt)
1.1 deraadt 549: {
1.119 markus 550: const char *msg, *again = "Please type 'yes' or 'no': ";
551: char *p;
552: int ret = -1;
1.96 markus 553:
554: if (options.batch_mode)
555: return 0;
1.119 markus 556: for (msg = prompt;;msg = again) {
557: p = read_passphrase(msg, RP_ECHO);
558: if (p == NULL ||
559: (p[0] == '\0') || (p[0] == '\n') ||
560: strncasecmp(p, "no", 2) == 0)
561: ret = 0;
1.127 markus 562: if (p && strncasecmp(p, "yes", 3) == 0)
1.119 markus 563: ret = 1;
564: if (p)
565: xfree(p);
566: if (ret != -1)
567: return ret;
1.1 deraadt 568: }
569: }
570:
1.39 deraadt 571: /*
1.108 markus 572: * check whether the supplied host key is valid, return -1 if the key
573: * is not valid. the user_hostfile will not be updated if 'readonly' is true.
1.39 deraadt 574: */
1.197 dtucker 575: #define RDRW 0
576: #define RDONLY 1
577: #define ROQUIET 2
1.109 itojun 578: static int
1.197 dtucker 579: check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
580: Key *host_key, int readonly, const char *user_hostfile,
581: const char *system_hostfile)
1.1 deraadt 582: {
1.58 markus 583: Key *file_key;
1.152 jakob 584: const char *type = key_type(host_key);
1.189 dtucker 585: char *ip = NULL, *host = NULL;
1.204 grunk 586: char hostline[1000], *hostp, *fp, *ra;
1.38 markus 587: HostStatus host_status;
588: HostStatus ip_status;
1.161 djm 589: int r, local = 0, host_ip_differ = 0;
1.49 markus 590: char ntop[NI_MAXHOST];
1.119 markus 591: char msg[1024];
1.210 dtucker 592: int len, host_line, ip_line, cancelled_forwarding = 0;
1.85 markus 593: const char *host_file = NULL, *ip_file = NULL;
1.49 markus 594:
595: /*
596: * Force accepting of the host key for loopback/localhost. The
597: * problem is that if the home directory is NFS-mounted to multiple
598: * machines, localhost will refer to a different machine in each of
599: * them, and the user will get bogus HOST_CHANGED warnings. This
600: * essentially disables host authentication for localhost; however,
601: * this is probably not a real problem.
602: */
1.70 markus 603: /** hostaddr == 0! */
1.49 markus 604: switch (hostaddr->sa_family) {
605: case AF_INET:
1.108 markus 606: local = (ntohl(((struct sockaddr_in *)hostaddr)->
1.168 djm 607: sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
1.49 markus 608: break;
609: case AF_INET6:
1.108 markus 610: local = IN6_IS_ADDR_LOOPBACK(
611: &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
1.49 markus 612: break;
613: default:
614: local = 0;
615: break;
616: }
1.111 markus 617: if (options.no_host_authentication_for_localhost == 1 && local &&
618: options.host_key_alias == NULL) {
1.88 markus 619: debug("Forcing accepting of host key for "
620: "loopback/localhost.");
1.108 markus 621: return 0;
1.49 markus 622: }
1.42 markus 623:
624: /*
1.88 markus 625: * We don't have the remote ip-address for connections
626: * using a proxy command
1.42 markus 627: */
1.84 markus 628: if (options.proxy_command == NULL) {
629: if (getnameinfo(hostaddr, hostaddr->sa_len, ntop, sizeof(ntop),
1.86 markus 630: NULL, 0, NI_NUMERICHOST) != 0)
1.84 markus 631: fatal("check_host_key: getnameinfo failed");
1.197 dtucker 632: ip = put_host_port(ntop, port);
1.84 markus 633: } else {
634: ip = xstrdup("<no hostip for proxy command>");
1.86 markus 635: }
1.206 grunk 636:
637: /*
1.88 markus 638: * Turn off check_host_ip if the connection is to localhost, via proxy
639: * command or if we don't have a hostname to compare with
640: */
1.189 dtucker 641: if (options.check_host_ip && (local ||
642: strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
1.88 markus 643: options.check_host_ip = 0;
1.86 markus 644:
645: /*
1.189 dtucker 646: * Allow the user to record the key under a different name or
647: * differentiate a non-standard port. This is useful for ssh
648: * tunneling over forwarded connections or if you run multiple
649: * sshd's on different ports on the same machine.
1.86 markus 650: */
651: if (options.host_key_alias != NULL) {
1.189 dtucker 652: host = xstrdup(options.host_key_alias);
1.86 markus 653: debug("using hostkeyalias: %s", host);
1.189 dtucker 654: } else {
1.197 dtucker 655: host = put_host_port(hostname, port);
1.84 markus 656: }
1.38 markus 657:
1.46 markus 658: /*
659: * Store the host key from the known host file in here so that we can
660: * compare it with the key for the IP address.
661: */
1.58 markus 662: file_key = key_new(host_key->type);
1.38 markus 663:
1.40 markus 664: /*
1.170 djm 665: * Check if the host key is present in the user's list of known
1.40 markus 666: * hosts or in the systemwide list.
667: */
1.85 markus 668: host_file = user_hostfile;
1.108 markus 669: host_status = check_host_in_hostfile(host_file, host, host_key,
1.118 deraadt 670: file_key, &host_line);
1.85 markus 671: if (host_status == HOST_NEW) {
672: host_file = system_hostfile;
1.108 markus 673: host_status = check_host_in_hostfile(host_file, host, host_key,
674: file_key, &host_line);
1.85 markus 675: }
1.40 markus 676: /*
677: * Also perform check for the ip address, skip the check if we are
678: * localhost or the hostname was an ip address to begin with
679: */
1.88 markus 680: if (options.check_host_ip) {
1.58 markus 681: Key *ip_key = key_new(host_key->type);
1.38 markus 682:
1.85 markus 683: ip_file = user_hostfile;
1.108 markus 684: ip_status = check_host_in_hostfile(ip_file, ip, host_key,
685: ip_key, &ip_line);
1.85 markus 686: if (ip_status == HOST_NEW) {
687: ip_file = system_hostfile;
1.108 markus 688: ip_status = check_host_in_hostfile(ip_file, ip,
689: host_key, ip_key, &ip_line);
1.85 markus 690: }
1.38 markus 691: if (host_status == HOST_CHANGED &&
1.58 markus 692: (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
1.38 markus 693: host_ip_differ = 1;
694:
1.58 markus 695: key_free(ip_key);
1.38 markus 696: } else
697: ip_status = host_status;
698:
1.58 markus 699: key_free(file_key);
1.38 markus 700:
701: switch (host_status) {
702: case HOST_OK:
703: /* The host is known and the key matches. */
1.72 markus 704: debug("Host '%.200s' is known and matches the %s host key.",
705: host, type);
1.85 markus 706: debug("Found key in %s:%d", host_file, host_line);
1.88 markus 707: if (options.check_host_ip && ip_status == HOST_NEW) {
1.108 markus 708: if (readonly)
1.138 itojun 709: logit("%s host key for IP address "
1.108 markus 710: "'%.128s' not in list of known hosts.",
711: type, ip);
712: else if (!add_host_to_hostfile(user_hostfile, ip,
1.160 djm 713: host_key, options.hash_known_hosts))
1.138 itojun 714: logit("Failed to add the %s host key for IP "
1.108 markus 715: "address '%.128s' to the list of known "
716: "hosts (%.30s).", type, ip, user_hostfile);
1.88 markus 717: else
1.138 itojun 718: logit("Warning: Permanently added the %s host "
1.108 markus 719: "key for IP address '%.128s' to the list "
720: "of known hosts.", type, ip);
1.209 grunk 721: } else if (options.visual_host_key) {
1.204 grunk 722: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
723: ra = key_fingerprint(host_key, SSH_FP_MD5,
724: SSH_FP_RANDOMART);
725: logit("Host key fingerprint is %s\n%s\n", fp, ra);
726: xfree(ra);
727: xfree(fp);
1.38 markus 728: }
729: break;
730: case HOST_NEW:
1.197 dtucker 731: if (options.host_key_alias == NULL && port != 0 &&
732: port != SSH_DEFAULT_PORT) {
733: debug("checking without port identifier");
1.212 stevesk 734: if (check_host_key(hostname, hostaddr, 0, host_key,
735: ROQUIET, user_hostfile, system_hostfile) == 0) {
1.197 dtucker 736: debug("found matching key w/out port");
737: break;
738: }
739: }
1.108 markus 740: if (readonly)
741: goto fail;
1.38 markus 742: /* The host is new. */
743: if (options.strict_host_key_checking == 1) {
1.108 markus 744: /*
745: * User has requested strict host key checking. We
746: * will not add the host key automatically. The only
747: * alternative left is to abort.
748: */
749: error("No %s host key is known for %.200s and you "
750: "have requested strict checking.", type, host);
751: goto fail;
1.38 markus 752: } else if (options.strict_host_key_checking == 2) {
1.145 jakob 753: char msg1[1024], msg2[1024];
754:
755: if (show_other_keys(host, host_key))
756: snprintf(msg1, sizeof(msg1),
1.168 djm 757: "\nbut keys of different type are already"
758: " known for this host.");
1.145 jakob 759: else
760: snprintf(msg1, sizeof(msg1), ".");
1.38 markus 761: /* The default */
1.100 markus 762: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 763: ra = key_fingerprint(host_key, SSH_FP_MD5,
764: SSH_FP_RANDOMART);
1.145 jakob 765: msg2[0] = '\0';
766: if (options.verify_host_key_dns) {
1.153 jakob 767: if (matching_host_key_dns)
1.145 jakob 768: snprintf(msg2, sizeof(msg2),
769: "Matching host key fingerprint"
770: " found in DNS.\n");
771: else
772: snprintf(msg2, sizeof(msg2),
773: "No matching host key fingerprint"
774: " found in DNS.\n");
775: }
1.119 markus 776: snprintf(msg, sizeof(msg),
1.108 markus 777: "The authenticity of host '%.200s (%s)' can't be "
1.132 markus 778: "established%s\n"
1.209 grunk 779: "%s key fingerprint is %s.%s%s\n%s"
1.108 markus 780: "Are you sure you want to continue connecting "
1.132 markus 781: "(yes/no)? ",
1.209 grunk 782: host, ip, msg1, type, fp,
783: options.visual_host_key ? "\n" : "",
784: options.visual_host_key ? ra : "",
785: msg2);
1.204 grunk 786: xfree(ra);
1.100 markus 787: xfree(fp);
1.119 markus 788: if (!confirm(msg))
1.108 markus 789: goto fail;
1.38 markus 790: }
1.161 djm 791: /*
792: * If not in strict mode, add the key automatically to the
793: * local known_hosts file.
794: */
1.88 markus 795: if (options.check_host_ip && ip_status == HOST_NEW) {
1.161 djm 796: snprintf(hostline, sizeof(hostline), "%s,%s",
797: host, ip);
1.38 markus 798: hostp = hostline;
1.161 djm 799: if (options.hash_known_hosts) {
800: /* Add hash of host and IP separately */
801: r = add_host_to_hostfile(user_hostfile, host,
802: host_key, options.hash_known_hosts) &&
803: add_host_to_hostfile(user_hostfile, ip,
804: host_key, options.hash_known_hosts);
805: } else {
806: /* Add unhashed "host,ip" */
807: r = add_host_to_hostfile(user_hostfile,
808: hostline, host_key,
809: options.hash_known_hosts);
810: }
811: } else {
812: r = add_host_to_hostfile(user_hostfile, host, host_key,
813: options.hash_known_hosts);
1.38 markus 814: hostp = host;
1.161 djm 815: }
1.38 markus 816:
1.161 djm 817: if (!r)
1.138 itojun 818: logit("Failed to add the host to the list of known "
1.108 markus 819: "hosts (%.500s).", user_hostfile);
1.38 markus 820: else
1.138 itojun 821: logit("Warning: Permanently added '%.200s' (%s) to the "
1.108 markus 822: "list of known hosts.", hostp, type);
1.38 markus 823: break;
824: case HOST_CHANGED:
1.197 dtucker 825: if (readonly == ROQUIET)
826: goto fail;
1.38 markus 827: if (options.check_host_ip && host_ip_differ) {
1.158 avsm 828: char *key_msg;
1.38 markus 829: if (ip_status == HOST_NEW)
1.158 avsm 830: key_msg = "is unknown";
1.38 markus 831: else if (ip_status == HOST_OK)
1.158 avsm 832: key_msg = "is unchanged";
1.38 markus 833: else
1.158 avsm 834: key_msg = "has a different value";
1.38 markus 835: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
836: error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
837: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1.72 markus 838: error("The %s host key for %s has changed,", type, host);
1.208 ian 839: error("and the key for the corresponding IP address %s", ip);
1.158 avsm 840: error("%s. This could either mean that", key_msg);
1.38 markus 841: error("DNS SPOOFING is happening or the IP address for the host");
1.85 markus 842: error("and its host key have changed at the same time.");
1.88 markus 843: if (ip_status != HOST_NEW)
1.85 markus 844: error("Offending key for IP in %s:%d", ip_file, ip_line);
1.38 markus 845: }
846: /* The host key has changed. */
1.150 jakob 847: warn_changed_key(host_key);
1.38 markus 848: error("Add correct host key in %.100s to get rid of this message.",
1.87 markus 849: user_hostfile);
1.85 markus 850: error("Offending key in %s:%d", host_file, host_line);
1.38 markus 851:
1.40 markus 852: /*
853: * If strict host key checking is in use, the user will have
854: * to edit the key manually and we can only abort.
855: */
1.108 markus 856: if (options.strict_host_key_checking) {
857: error("%s host key for %.200s has changed and you have "
858: "requested strict checking.", type, host);
859: goto fail;
860: }
1.38 markus 861:
1.40 markus 862: /*
863: * If strict host key checking has not been requested, allow
1.144 djm 864: * the connection but without MITM-able authentication or
1.194 stevesk 865: * forwarding.
1.40 markus 866: */
1.38 markus 867: if (options.password_authentication) {
1.108 markus 868: error("Password authentication is disabled to avoid "
869: "man-in-the-middle attacks.");
1.38 markus 870: options.password_authentication = 0;
1.210 dtucker 871: cancelled_forwarding = 1;
1.144 djm 872: }
873: if (options.kbd_interactive_authentication) {
874: error("Keyboard-interactive authentication is disabled"
875: " to avoid man-in-the-middle attacks.");
876: options.kbd_interactive_authentication = 0;
877: options.challenge_response_authentication = 0;
1.210 dtucker 878: cancelled_forwarding = 1;
1.144 djm 879: }
880: if (options.challenge_response_authentication) {
881: error("Challenge/response authentication is disabled"
882: " to avoid man-in-the-middle attacks.");
883: options.challenge_response_authentication = 0;
1.210 dtucker 884: cancelled_forwarding = 1;
1.38 markus 885: }
886: if (options.forward_agent) {
1.108 markus 887: error("Agent forwarding is disabled to avoid "
888: "man-in-the-middle attacks.");
1.38 markus 889: options.forward_agent = 0;
1.210 dtucker 890: cancelled_forwarding = 1;
1.83 markus 891: }
892: if (options.forward_x11) {
1.108 markus 893: error("X11 forwarding is disabled to avoid "
894: "man-in-the-middle attacks.");
1.83 markus 895: options.forward_x11 = 0;
1.210 dtucker 896: cancelled_forwarding = 1;
1.83 markus 897: }
1.108 markus 898: if (options.num_local_forwards > 0 ||
899: options.num_remote_forwards > 0) {
900: error("Port forwarding is disabled to avoid "
901: "man-in-the-middle attacks.");
902: options.num_local_forwards =
1.118 deraadt 903: options.num_remote_forwards = 0;
1.210 dtucker 904: cancelled_forwarding = 1;
1.194 stevesk 905: }
906: if (options.tun_open != SSH_TUNMODE_NO) {
907: error("Tunnel forwarding is disabled to avoid "
908: "man-in-the-middle attacks.");
909: options.tun_open = SSH_TUNMODE_NO;
1.210 dtucker 910: cancelled_forwarding = 1;
1.38 markus 911: }
1.210 dtucker 912: if (options.exit_on_forward_failure && cancelled_forwarding)
913: fatal("Error: forwarding disabled due to host key "
914: "check failure");
915:
1.40 markus 916: /*
917: * XXX Should permit the user to change to use the new id.
918: * This could be done by converting the host key to an
919: * identifying sentence, tell that the host identifies itself
920: * by that sentence, and ask the user if he/she whishes to
921: * accept the authentication.
922: */
1.38 markus 923: break;
1.132 markus 924: case HOST_FOUND:
925: fatal("internal error");
926: break;
1.88 markus 927: }
928:
929: if (options.check_host_ip && host_status != HOST_CHANGED &&
930: ip_status == HOST_CHANGED) {
1.119 markus 931: snprintf(msg, sizeof(msg),
932: "Warning: the %s host key for '%.200s' "
933: "differs from the key for the IP address '%.128s'"
934: "\nOffending key for IP in %s:%d",
935: type, host, ip, ip_file, ip_line);
936: if (host_status == HOST_OK) {
937: len = strlen(msg);
938: snprintf(msg + len, sizeof(msg) - len,
939: "\nMatching host key in %s:%d",
1.125 deraadt 940: host_file, host_line);
1.119 markus 941: }
1.88 markus 942: if (options.strict_host_key_checking == 1) {
1.143 djm 943: logit("%s", msg);
1.108 markus 944: error("Exiting, you have requested strict checking.");
945: goto fail;
1.88 markus 946: } else if (options.strict_host_key_checking == 2) {
1.119 markus 947: strlcat(msg, "\nAre you sure you want "
948: "to continue connecting (yes/no)? ", sizeof(msg));
949: if (!confirm(msg))
1.108 markus 950: goto fail;
1.119 markus 951: } else {
1.143 djm 952: logit("%s", msg);
1.88 markus 953: }
1.38 markus 954: }
1.82 provos 955:
956: xfree(ip);
1.189 dtucker 957: xfree(host);
1.108 markus 958: return 0;
959:
960: fail:
961: xfree(ip);
1.189 dtucker 962: xfree(host);
1.108 markus 963: return -1;
964: }
965:
1.140 jakob 966: /* returns 0 if key verifies or -1 if key does NOT verify */
1.108 markus 967: int
968: verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
969: {
970: struct stat st;
1.153 jakob 971: int flags = 0;
1.140 jakob 972:
1.153 jakob 973: if (options.verify_host_key_dns &&
974: verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
975:
976: if (flags & DNS_VERIFY_FOUND) {
977:
978: if (options.verify_host_key_dns == 1 &&
979: flags & DNS_VERIFY_MATCH &&
980: flags & DNS_VERIFY_SECURE)
981: return 0;
982:
983: if (flags & DNS_VERIFY_MATCH) {
984: matching_host_key_dns = 1;
985: } else {
986: warn_changed_key(host_key);
987: error("Update the SSHFP RR in DNS with the new "
988: "host key to get rid of this message.");
989: }
1.140 jakob 990: }
991: }
1.108 markus 992:
993: /* return ok if the key can be found in an old keyfile */
994: if (stat(options.system_hostfile2, &st) == 0 ||
995: stat(options.user_hostfile2, &st) == 0) {
1.197 dtucker 996: if (check_host_key(host, hostaddr, options.port, host_key,
997: RDONLY, options.user_hostfile2,
998: options.system_hostfile2) == 0)
1.108 markus 999: return 0;
1000: }
1.197 dtucker 1001: return check_host_key(host, hostaddr, options.port, host_key,
1002: RDRW, options.user_hostfile, options.system_hostfile);
1.51 markus 1003: }
1.70 markus 1004:
1.51 markus 1005: /*
1006: * Starts a dialog with the server, and authenticates the current user on the
1007: * server. This does not need any extra privileges. The basic connection
1008: * to the server must already have been established before this is called.
1009: * If login fails, this function prints an error and never returns.
1010: * This function does not require super-user privileges.
1011: */
1012: void
1.120 markus 1013: ssh_login(Sensitive *sensitive, const char *orighost,
1.202 djm 1014: struct sockaddr *hostaddr, struct passwd *pw, int timeout_ms)
1.51 markus 1015: {
1016: char *host, *cp;
1.70 markus 1017: char *server_user, *local_user;
1018:
1019: local_user = xstrdup(pw->pw_name);
1020: server_user = options.user ? options.user : local_user;
1.51 markus 1021:
1022: /* Convert the user-supplied hostname into all lowercase. */
1023: host = xstrdup(orighost);
1024: for (cp = host; *cp; cp++)
1025: if (isupper(*cp))
1.178 deraadt 1026: *cp = (char)tolower(*cp);
1.51 markus 1027:
1028: /* Exchange protocol version identification strings with the server. */
1.202 djm 1029: ssh_exchange_identification(timeout_ms);
1.51 markus 1030:
1031: /* Put the connection into non-blocking mode. */
1032: packet_set_nonblocking();
1033:
1034: /* key exchange */
1035: /* authenticate user */
1.59 markus 1036: if (compat20) {
1037: ssh_kex2(host, hostaddr);
1.120 markus 1038: ssh_userauth2(local_user, server_user, host, sensitive);
1.59 markus 1039: } else {
1040: ssh_kex(host, hostaddr);
1.120 markus 1041: ssh_userauth1(local_user, server_user, host, sensitive);
1.59 markus 1042: }
1.182 markus 1043: xfree(local_user);
1.97 markus 1044: }
1045:
1046: void
1047: ssh_put_password(char *password)
1048: {
1049: int size;
1050: char *padded;
1051:
1.99 deraadt 1052: if (datafellows & SSH_BUG_PASSWORDPAD) {
1.107 markus 1053: packet_put_cstring(password);
1.99 deraadt 1054: return;
1055: }
1.97 markus 1056: size = roundup(strlen(password) + 1, 32);
1.179 djm 1057: padded = xcalloc(1, size);
1.97 markus 1058: strlcpy(padded, password, size);
1059: packet_put_string(padded, size);
1060: memset(padded, 0, size);
1061: xfree(padded);
1.132 markus 1062: }
1063:
1064: static int
1065: show_key_from_file(const char *file, const char *host, int keytype)
1066: {
1067: Key *found;
1.204 grunk 1068: char *fp, *ra;
1.132 markus 1069: int line, ret;
1070:
1071: found = key_new(keytype);
1072: if ((ret = lookup_key_in_hostfile_by_type(file, host,
1073: keytype, found, &line))) {
1074: fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 1075: ra = key_fingerprint(found, SSH_FP_MD5, SSH_FP_RANDOMART);
1.138 itojun 1076: logit("WARNING: %s key found for host %s\n"
1.133 markus 1077: "in %s:%d\n"
1.204 grunk 1078: "%s key fingerprint %s.\n%s\n",
1.132 markus 1079: key_type(found), host, file, line,
1.204 grunk 1080: key_type(found), fp, ra);
1081: xfree(ra);
1.132 markus 1082: xfree(fp);
1083: }
1084: key_free(found);
1085: return (ret);
1086: }
1087:
1088: /* print all known host keys for a given host, but skip keys of given type */
1089: static int
1090: show_other_keys(const char *host, Key *key)
1091: {
1092: int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1};
1093: int i, found = 0;
1094:
1095: for (i = 0; type[i] != -1; i++) {
1096: if (type[i] == key->type)
1097: continue;
1098: if (type[i] != KEY_RSA1 &&
1099: show_key_from_file(options.user_hostfile2, host, type[i])) {
1100: found = 1;
1101: continue;
1102: }
1103: if (type[i] != KEY_RSA1 &&
1104: show_key_from_file(options.system_hostfile2, host, type[i])) {
1105: found = 1;
1106: continue;
1107: }
1108: if (show_key_from_file(options.user_hostfile, host, type[i])) {
1109: found = 1;
1110: continue;
1111: }
1112: if (show_key_from_file(options.system_hostfile, host, type[i])) {
1113: found = 1;
1114: continue;
1115: }
1116: debug2("no key of type %d for host %s", type[i], host);
1117: }
1118: return (found);
1.150 jakob 1119: }
1120:
1121: static void
1122: warn_changed_key(Key *host_key)
1123: {
1124: char *fp;
1.151 jakob 1125: const char *type = key_type(host_key);
1.150 jakob 1126:
1127: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1128:
1129: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1130: error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1131: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1132: error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1133: error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1134: error("It is also possible that the %s host key has just been changed.", type);
1135: error("The fingerprint for the %s key sent by the remote host is\n%s.",
1136: type, fp);
1137: error("Please contact your system administrator.");
1138:
1139: xfree(fp);
1.171 reyk 1140: }
1141:
1142: /*
1143: * Execute a local command
1144: */
1145: int
1146: ssh_local_cmd(const char *args)
1147: {
1148: char *shell;
1149: pid_t pid;
1150: int status;
1151:
1152: if (!options.permit_local_command ||
1153: args == NULL || !*args)
1154: return (1);
1155:
1156: if ((shell = getenv("SHELL")) == NULL)
1157: shell = _PATH_BSHELL;
1158:
1159: pid = fork();
1160: if (pid == 0) {
1161: debug3("Executing %s -c \"%s\"", shell, args);
1162: execl(shell, shell, "-c", args, (char *)NULL);
1163: error("Couldn't execute %s -c \"%s\": %s",
1164: shell, args, strerror(errno));
1165: _exit(1);
1166: } else if (pid == -1)
1167: fatal("fork failed: %.100s", strerror(errno));
1168: while (waitpid(pid, &status, 0) == -1)
1169: if (errno != EINTR)
1170: fatal("Couldn't wait for child: %s", strerror(errno));
1171:
1172: if (!WIFEXITED(status))
1173: return (1);
1174:
1175: return (WEXITSTATUS(status));
1.1 deraadt 1176: }
![[BACK]](/icons/back.gif){kind=icon}
Return to sshconnect.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh