Annotation of src/usr.bin/ssh/sshconnect.c, Revision 1.227
1.227 ! djm 1: /* $OpenBSD: sshconnect.c,v 1.226 2010/10/05 05:13:18 djm 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"
1.219 djm 52: #include "ssh2.h"
1.186 stevesk 53: #include "version.h"
1.140 jakob 54:
1.70 markus 55: char *client_version_string = NULL;
56: char *server_version_string = NULL;
1.59 markus 57:
1.169 stevesk 58: static int matching_host_key_dns = 0;
1.145 jakob 59:
1.227 ! djm 60: static pid_t proxy_command_pid = 0;
! 61:
1.124 markus 62: /* import */
1.43 markus 63: extern Options options;
1.50 markus 64: extern char *__progname;
1.124 markus 65: extern uid_t original_real_uid;
66: extern uid_t original_effective_uid;
1.91 markus 67:
1.132 markus 68: static int show_other_keys(const char *, Key *);
1.150 jakob 69: static void warn_changed_key(Key *);
1.132 markus 70:
1.39 deraadt 71: /*
72: * Connect to the given ssh server using a proxy command.
73: */
1.109 itojun 74: static int
1.124 markus 75: ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
1.1 deraadt 76: {
1.164 djm 77: char *command_string, *tmp;
1.38 markus 78: int pin[2], pout[2];
1.69 deraadt 79: pid_t pid;
1.201 djm 80: char *shell, strport[NI_MAXSERV];
81:
1.226 djm 82: if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
1.201 djm 83: shell = _PATH_BSHELL;
1.38 markus 84:
85: /* Convert the port number into a string. */
1.49 markus 86: snprintf(strport, sizeof strport, "%hu", port);
1.38 markus 87:
1.135 djm 88: /*
89: * Build the final command string in the buffer by making the
90: * appropriate substitutions to the given proxy command.
91: *
1.154 djm 92: * Use "exec" to avoid "sh -c" processes on some platforms
1.135 djm 93: * (e.g. Solaris)
94: */
1.179 djm 95: xasprintf(&tmp, "exec %s", proxy_command);
1.222 djm 96: command_string = percent_expand(tmp, "h", host, "p", strport,
1.224 djm 97: "r", options.user, (char *)NULL);
1.164 djm 98: xfree(tmp);
1.38 markus 99:
100: /* Create pipes for communicating with the proxy. */
101: if (pipe(pin) < 0 || pipe(pout) < 0)
102: fatal("Could not create pipes to communicate with the proxy: %.100s",
1.118 deraadt 103: strerror(errno));
1.38 markus 104:
105: debug("Executing proxy command: %.500s", command_string);
106:
107: /* Fork and execute the proxy command. */
108: if ((pid = fork()) == 0) {
109: char *argv[10];
110:
111: /* Child. Permanently give up superuser privileges. */
1.184 markus 112: permanently_drop_suid(original_real_uid);
1.38 markus 113:
114: /* Redirect stdin and stdout. */
115: close(pin[1]);
116: if (pin[0] != 0) {
117: if (dup2(pin[0], 0) < 0)
118: perror("dup2 stdin");
119: close(pin[0]);
120: }
121: close(pout[0]);
122: if (dup2(pout[1], 1) < 0)
123: perror("dup2 stdout");
124: /* Cannot be 1 because pin allocated two descriptors. */
125: close(pout[1]);
126:
127: /* Stderr is left as it is so that error messages get
128: printed on the user's terminal. */
1.201 djm 129: argv[0] = shell;
1.38 markus 130: argv[1] = "-c";
131: argv[2] = command_string;
132: argv[3] = NULL;
133:
134: /* Execute the proxy command. Note that we gave up any
135: extra privileges above. */
1.89 markus 136: execv(argv[0], argv);
137: perror(argv[0]);
1.38 markus 138: exit(1);
139: }
140: /* Parent. */
141: if (pid < 0)
142: fatal("fork failed: %.100s", strerror(errno));
1.135 djm 143: else
144: proxy_command_pid = pid; /* save pid to clean up later */
1.38 markus 145:
146: /* Close child side of the descriptors. */
147: close(pin[0]);
148: close(pout[1]);
149:
150: /* Free the command name. */
1.164 djm 151: xfree(command_string);
1.38 markus 152:
153: /* Set the connection file descriptors. */
154: packet_set_connection(pout[0], pin[1]);
1.207 dtucker 155: packet_set_timeout(options.server_alive_interval,
156: options.server_alive_count_max);
1.1 deraadt 157:
1.110 markus 158: /* Indicate OK return */
159: return 0;
1.227 ! djm 160: }
! 161:
! 162: void
! 163: ssh_kill_proxy_command(void)
! 164: {
! 165: /*
! 166: * Send SIGHUP to proxy command if used. We don't wait() in
! 167: * case it hangs and instead rely on init to reap the child
! 168: */
! 169: if (proxy_command_pid > 1)
! 170: kill(SIGHUP, proxy_command_pid);
1.1 deraadt 171: }
172:
1.39 deraadt 173: /*
174: * Creates a (possibly privileged) socket for use as the ssh connection.
175: */
1.109 itojun 176: static int
1.139 markus 177: ssh_create_socket(int privileged, struct addrinfo *ai)
1.1 deraadt 178: {
1.105 markus 179: int sock, gaierr;
180: struct addrinfo hints, *res;
1.1 deraadt 181:
1.40 markus 182: /*
183: * If we are running as root and want to connect to a privileged
184: * port, bind our own socket to a privileged port.
185: */
1.38 markus 186: if (privileged) {
187: int p = IPPORT_RESERVED - 1;
1.124 markus 188: PRIV_START;
1.139 markus 189: sock = rresvport_af(&p, ai->ai_family);
1.124 markus 190: PRIV_END;
1.38 markus 191: if (sock < 0)
1.139 markus 192: error("rresvport: af=%d %.100s", ai->ai_family,
193: strerror(errno));
1.55 markus 194: else
195: debug("Allocated local port %d.", p);
1.105 markus 196: return sock;
197: }
1.217 dtucker 198: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.216 dtucker 199: if (sock < 0) {
1.105 markus 200: error("socket: %.100s", strerror(errno));
1.216 dtucker 201: return -1;
202: }
203: fcntl(sock, F_SETFD, FD_CLOEXEC);
1.105 markus 204:
205: /* Bind the socket to an alternative local IP address */
206: if (options.bind_address == NULL)
207: return sock;
208:
209: memset(&hints, 0, sizeof(hints));
1.139 markus 210: hints.ai_family = ai->ai_family;
211: hints.ai_socktype = ai->ai_socktype;
212: hints.ai_protocol = ai->ai_protocol;
1.105 markus 213: hints.ai_flags = AI_PASSIVE;
1.205 dtucker 214: gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res);
1.105 markus 215: if (gaierr) {
216: error("getaddrinfo: %s: %s", options.bind_address,
1.203 dtucker 217: ssh_gai_strerror(gaierr));
1.105 markus 218: close(sock);
219: return -1;
220: }
221: if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
222: error("bind: %s: %s", options.bind_address, strerror(errno));
223: close(sock);
224: freeaddrinfo(res);
225: return -1;
1.38 markus 226: }
1.105 markus 227: freeaddrinfo(res);
1.38 markus 228: return sock;
1.1 deraadt 229: }
230:
1.141 djm 231: static int
232: timeout_connect(int sockfd, const struct sockaddr *serv_addr,
1.202 djm 233: socklen_t addrlen, int *timeoutp)
1.141 djm 234: {
235: fd_set *fdset;
1.202 djm 236: struct timeval tv, t_start;
1.141 djm 237: socklen_t optlen;
1.179 djm 238: int optval, rc, result = -1;
1.141 djm 239:
1.202 djm 240: gettimeofday(&t_start, NULL);
241:
242: if (*timeoutp <= 0) {
243: result = connect(sockfd, serv_addr, addrlen);
244: goto done;
245: }
1.141 djm 246:
1.156 djm 247: set_nonblock(sockfd);
1.141 djm 248: rc = connect(sockfd, serv_addr, addrlen);
1.156 djm 249: if (rc == 0) {
250: unset_nonblock(sockfd);
1.202 djm 251: result = 0;
252: goto done;
253: }
254: if (errno != EINPROGRESS) {
255: result = -1;
256: goto done;
1.156 djm 257: }
1.141 djm 258:
1.179 djm 259: fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
260: sizeof(fd_mask));
1.141 djm 261: FD_SET(sockfd, fdset);
1.202 djm 262: ms_to_timeval(&tv, *timeoutp);
1.141 djm 263:
1.162 deraadt 264: for (;;) {
1.141 djm 265: rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
266: if (rc != -1 || errno != EINTR)
267: break;
268: }
269:
1.162 deraadt 270: switch (rc) {
1.141 djm 271: case 0:
272: /* Timed out */
273: errno = ETIMEDOUT;
1.142 djm 274: break;
1.141 djm 275: case -1:
276: /* Select error */
1.154 djm 277: debug("select: %s", strerror(errno));
1.142 djm 278: break;
1.141 djm 279: case 1:
280: /* Completed or failed */
281: optval = 0;
282: optlen = sizeof(optval);
1.154 djm 283: if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
1.148 markus 284: &optlen) == -1) {
1.154 djm 285: debug("getsockopt: %s", strerror(errno));
1.142 djm 286: break;
1.148 markus 287: }
1.141 djm 288: if (optval != 0) {
289: errno = optval;
1.142 djm 290: break;
1.141 djm 291: }
1.142 djm 292: result = 0;
1.156 djm 293: unset_nonblock(sockfd);
1.141 djm 294: break;
295: default:
296: /* Should not occur */
297: fatal("Bogus return (%d) from select()", rc);
298: }
299:
1.142 djm 300: xfree(fdset);
1.202 djm 301:
302: done:
303: if (result == 0 && *timeoutp > 0) {
304: ms_subtract_diff(&t_start, timeoutp);
305: if (*timeoutp <= 0) {
306: errno = ETIMEDOUT;
307: result = -1;
308: }
309: }
310:
1.142 djm 311: return (result);
1.141 djm 312: }
313:
1.39 deraadt 314: /*
1.49 markus 315: * Opens a TCP/IP connection to the remote server on the given host.
316: * The address of the remote host will be returned in hostaddr.
1.124 markus 317: * If port is 0, the default port will be used. If needpriv is true,
1.39 deraadt 318: * a privileged port will be allocated to make the connection.
1.124 markus 319: * This requires super-user privileges if needpriv is true.
1.39 deraadt 320: * Connection_attempts specifies the maximum number of tries (one per
321: * second). If proxy_command is non-NULL, it specifies the command (with %h
322: * and %p substituted for host and port, respectively) to use to contact
323: * the daemon.
324: */
1.38 markus 325: int
1.49 markus 326: ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
1.202 djm 327: u_short port, int family, int connection_attempts, int *timeout_ms,
328: int want_keepalive, int needpriv, const char *proxy_command)
1.1 deraadt 329: {
1.90 markus 330: int gaierr;
331: int on = 1;
1.49 markus 332: int sock = -1, attempt;
1.90 markus 333: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.49 markus 334: struct addrinfo hints, *ai, *aitop;
1.38 markus 335:
1.136 markus 336: debug2("ssh_connect: needpriv %d", needpriv);
1.38 markus 337:
338: /* If a proxy command is given, connect using it. */
339: if (proxy_command != NULL)
1.124 markus 340: return ssh_proxy_connect(host, port, proxy_command);
1.38 markus 341:
342: /* No proxy command. */
343:
1.49 markus 344: memset(&hints, 0, sizeof(hints));
1.115 markus 345: hints.ai_family = family;
1.49 markus 346: hints.ai_socktype = SOCK_STREAM;
1.126 deraadt 347: snprintf(strport, sizeof strport, "%u", port);
1.49 markus 348: if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
1.203 dtucker 349: fatal("%s: Could not resolve hostname %.100s: %s", __progname,
350: host, ssh_gai_strerror(gaierr));
1.38 markus 351:
1.181 markus 352: for (attempt = 0; attempt < connection_attempts; attempt++) {
1.200 markus 353: if (attempt > 0) {
354: /* Sleep a moment before retrying. */
355: sleep(1);
1.38 markus 356: debug("Trying again...");
1.200 markus 357: }
1.181 markus 358: /*
359: * Loop through addresses for this host, and try each one in
360: * sequence until the connection succeeds.
361: */
1.49 markus 362: for (ai = aitop; ai; ai = ai->ai_next) {
363: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
364: continue;
365: if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
366: ntop, sizeof(ntop), strport, sizeof(strport),
367: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
368: error("ssh_connect: getnameinfo failed");
369: continue;
370: }
371: debug("Connecting to %.200s [%.100s] port %s.",
372: host, ntop, strport);
373:
374: /* Create a socket for connecting. */
1.139 markus 375: sock = ssh_create_socket(needpriv, ai);
1.49 markus 376: if (sock < 0)
1.110 markus 377: /* Any error is already output */
1.49 markus 378: continue;
379:
1.141 djm 380: if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
1.202 djm 381: timeout_ms) >= 0) {
1.49 markus 382: /* Successful connection. */
1.102 markus 383: memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
1.38 markus 384: break;
1.49 markus 385: } else {
1.131 itojun 386: debug("connect to address %s port %s: %s",
387: ntop, strport, strerror(errno));
1.38 markus 388: close(sock);
1.181 markus 389: sock = -1;
1.38 markus 390: }
391: }
1.181 markus 392: if (sock != -1)
1.49 markus 393: break; /* Successful connection. */
1.38 markus 394: }
1.49 markus 395:
396: freeaddrinfo(aitop);
397:
1.38 markus 398: /* Return failure if we didn't get a successful connection. */
1.181 markus 399: if (sock == -1) {
1.159 markus 400: error("ssh: connect to host %s port %s: %s",
1.130 itojun 401: host, strport, strerror(errno));
1.159 markus 402: return (-1);
1.130 itojun 403: }
1.38 markus 404:
405: debug("Connection established.");
1.90 markus 406:
1.155 markus 407: /* Set SO_KEEPALIVE if requested. */
1.202 djm 408: if (want_keepalive &&
1.90 markus 409: setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
410: sizeof(on)) < 0)
411: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.38 markus 412:
413: /* Set the connection. */
414: packet_set_connection(sock, sock);
1.207 dtucker 415: packet_set_timeout(options.server_alive_interval,
416: options.server_alive_count_max);
1.1 deraadt 417:
1.110 markus 418: return 0;
1.59 markus 419: }
420:
1.43 markus 421: /*
1.39 deraadt 422: * Waits for the server identification string, and sends our own
423: * identification string.
424: */
1.213 andreas 425: void
1.202 djm 426: ssh_exchange_identification(int timeout_ms)
1.1 deraadt 427: {
1.38 markus 428: char buf[256], remote_version[256]; /* must be same size! */
1.165 djm 429: int remote_major, remote_minor, mismatch;
1.38 markus 430: int connection_in = packet_get_connection_in();
431: int connection_out = packet_get_connection_out();
1.93 stevesk 432: int minor1 = PROTOCOL_MINOR_1;
1.185 djm 433: u_int i, n;
1.202 djm 434: size_t len;
435: int fdsetsz, remaining, rc;
436: struct timeval t_start, t_remaining;
437: fd_set *fdset;
438:
439: fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask);
440: fdset = xcalloc(1, fdsetsz);
1.38 markus 441:
1.163 avsm 442: /* Read other side's version identification. */
1.202 djm 443: remaining = timeout_ms;
1.185 djm 444: for (n = 0;;) {
1.75 markus 445: for (i = 0; i < sizeof(buf) - 1; i++) {
1.202 djm 446: if (timeout_ms > 0) {
447: gettimeofday(&t_start, NULL);
448: ms_to_timeval(&t_remaining, remaining);
449: FD_SET(connection_in, fdset);
450: rc = select(connection_in + 1, fdset, NULL,
451: fdset, &t_remaining);
452: ms_subtract_diff(&t_start, &remaining);
453: if (rc == 0 || remaining <= 0)
454: fatal("Connection timed out during "
455: "banner exchange");
456: if (rc == -1) {
457: if (errno == EINTR)
458: continue;
459: fatal("ssh_exchange_identification: "
460: "select: %s", strerror(errno));
461: }
462: }
463:
1.214 andreas 464: len = roaming_atomicio(read, connection_in, &buf[i], 1);
1.163 avsm 465:
1.167 djm 466: if (len != 1 && errno == EPIPE)
1.202 djm 467: fatal("ssh_exchange_identification: "
468: "Connection closed by remote host");
1.163 avsm 469: else if (len != 1)
1.202 djm 470: fatal("ssh_exchange_identification: "
471: "read: %.100s", strerror(errno));
1.75 markus 472: if (buf[i] == '\r') {
473: buf[i] = '\n';
474: buf[i + 1] = 0;
475: continue; /**XXX wait for \n */
476: }
477: if (buf[i] == '\n') {
478: buf[i + 1] = 0;
479: break;
480: }
1.185 djm 481: if (++n > 65536)
1.202 djm 482: fatal("ssh_exchange_identification: "
483: "No banner received");
1.38 markus 484: }
1.75 markus 485: buf[sizeof(buf) - 1] = 0;
1.76 markus 486: if (strncmp(buf, "SSH-", 4) == 0)
1.38 markus 487: break;
1.75 markus 488: debug("ssh_exchange_identification: %s", buf);
1.38 markus 489: }
1.59 markus 490: server_version_string = xstrdup(buf);
1.202 djm 491: xfree(fdset);
1.38 markus 492:
1.40 markus 493: /*
494: * Check that the versions match. In future this might accept
495: * several versions and set appropriate flags to handle them.
496: */
1.59 markus 497: if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
498: &remote_major, &remote_minor, remote_version) != 3)
1.38 markus 499: fatal("Bad remote protocol version identification: '%.100s'", buf);
500: debug("Remote protocol version %d.%d, remote software version %.100s",
1.118 deraadt 501: remote_major, remote_minor, remote_version);
1.38 markus 502:
1.59 markus 503: compat_datafellows(remote_version);
1.64 markus 504: mismatch = 0;
1.59 markus 505:
1.116 deraadt 506: switch (remote_major) {
1.64 markus 507: case 1:
508: if (remote_minor == 99 &&
509: (options.protocol & SSH_PROTO_2) &&
510: !(options.protocol & SSH_PROTO_1_PREFERRED)) {
511: enable_compat20();
512: break;
513: }
514: if (!(options.protocol & SSH_PROTO_1)) {
515: mismatch = 1;
516: break;
517: }
518: if (remote_minor < 3) {
519: fatal("Remote machine has too old SSH software version.");
1.81 markus 520: } else if (remote_minor == 3 || remote_minor == 4) {
1.64 markus 521: /* We speak 1.3, too. */
522: enable_compat13();
1.81 markus 523: minor1 = 3;
1.64 markus 524: if (options.forward_agent) {
1.138 itojun 525: logit("Agent forwarding disabled for protocol 1.3");
1.64 markus 526: options.forward_agent = 0;
527: }
528: }
529: break;
530: case 2:
531: if (options.protocol & SSH_PROTO_2) {
532: enable_compat20();
533: break;
1.38 markus 534: }
1.64 markus 535: /* FALLTHROUGH */
1.68 markus 536: default:
1.64 markus 537: mismatch = 1;
538: break;
1.38 markus 539: }
1.64 markus 540: if (mismatch)
1.38 markus 541: fatal("Protocol major versions differ: %d vs. %d",
1.64 markus 542: (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
543: remote_major);
1.38 markus 544: /* Send our own protocol version identification. */
1.211 dtucker 545: snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s%s",
1.64 markus 546: compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
1.81 markus 547: compat20 ? PROTOCOL_MINOR_2 : minor1,
1.211 dtucker 548: SSH_VERSION, compat20 ? "\r\n" : "\n");
1.214 andreas 549: if (roaming_atomicio(vwrite, connection_out, buf, strlen(buf))
550: != strlen(buf))
1.38 markus 551: fatal("write: %.100s", strerror(errno));
1.59 markus 552: client_version_string = xstrdup(buf);
553: chop(client_version_string);
554: chop(server_version_string);
555: debug("Local version string %.100s", client_version_string);
1.1 deraadt 556: }
557:
1.96 markus 558: /* defaults to 'no' */
1.109 itojun 559: static int
1.112 markus 560: confirm(const char *prompt)
1.1 deraadt 561: {
1.119 markus 562: const char *msg, *again = "Please type 'yes' or 'no': ";
563: char *p;
564: int ret = -1;
1.96 markus 565:
566: if (options.batch_mode)
567: return 0;
1.119 markus 568: for (msg = prompt;;msg = again) {
569: p = read_passphrase(msg, RP_ECHO);
570: if (p == NULL ||
571: (p[0] == '\0') || (p[0] == '\n') ||
572: strncasecmp(p, "no", 2) == 0)
573: ret = 0;
1.127 markus 574: if (p && strncasecmp(p, "yes", 3) == 0)
1.119 markus 575: ret = 1;
576: if (p)
577: xfree(p);
578: if (ret != -1)
579: return ret;
1.1 deraadt 580: }
581: }
582:
1.219 djm 583: static int
584: check_host_cert(const char *host, const Key *host_key)
585: {
586: const char *reason;
587:
588: if (key_cert_check_authority(host_key, 1, 0, host, &reason) != 0) {
589: error("%s", reason);
590: return 0;
591: }
1.223 djm 592: if (buffer_len(&host_key->cert->critical) != 0) {
593: error("Certificate for %s contains unsupported "
594: "critical options(s)", host);
1.219 djm 595: return 0;
596: }
597: return 1;
598: }
599:
1.39 deraadt 600: /*
1.108 markus 601: * check whether the supplied host key is valid, return -1 if the key
602: * is not valid. the user_hostfile will not be updated if 'readonly' is true.
1.39 deraadt 603: */
1.197 dtucker 604: #define RDRW 0
605: #define RDONLY 1
606: #define ROQUIET 2
1.109 itojun 607: static int
1.197 dtucker 608: check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
609: Key *host_key, int readonly, const char *user_hostfile,
610: const char *system_hostfile)
1.1 deraadt 611: {
1.219 djm 612: Key *file_key, *raw_key = NULL;
613: const char *type;
1.189 dtucker 614: char *ip = NULL, *host = NULL;
1.204 grunk 615: char hostline[1000], *hostp, *fp, *ra;
1.38 markus 616: HostStatus host_status;
617: HostStatus ip_status;
1.219 djm 618: int r, want_cert, local = 0, host_ip_differ = 0;
1.49 markus 619: char ntop[NI_MAXHOST];
1.119 markus 620: char msg[1024];
1.210 dtucker 621: int len, host_line, ip_line, cancelled_forwarding = 0;
1.85 markus 622: const char *host_file = NULL, *ip_file = NULL;
1.49 markus 623:
624: /*
625: * Force accepting of the host key for loopback/localhost. The
626: * problem is that if the home directory is NFS-mounted to multiple
627: * machines, localhost will refer to a different machine in each of
628: * them, and the user will get bogus HOST_CHANGED warnings. This
629: * essentially disables host authentication for localhost; however,
630: * this is probably not a real problem.
631: */
1.70 markus 632: /** hostaddr == 0! */
1.49 markus 633: switch (hostaddr->sa_family) {
634: case AF_INET:
1.108 markus 635: local = (ntohl(((struct sockaddr_in *)hostaddr)->
1.168 djm 636: sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
1.49 markus 637: break;
638: case AF_INET6:
1.108 markus 639: local = IN6_IS_ADDR_LOOPBACK(
640: &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
1.49 markus 641: break;
642: default:
643: local = 0;
644: break;
645: }
1.111 markus 646: if (options.no_host_authentication_for_localhost == 1 && local &&
647: options.host_key_alias == NULL) {
1.88 markus 648: debug("Forcing accepting of host key for "
649: "loopback/localhost.");
1.108 markus 650: return 0;
1.49 markus 651: }
1.42 markus 652:
653: /*
1.88 markus 654: * We don't have the remote ip-address for connections
655: * using a proxy command
1.42 markus 656: */
1.84 markus 657: if (options.proxy_command == NULL) {
658: if (getnameinfo(hostaddr, hostaddr->sa_len, ntop, sizeof(ntop),
1.86 markus 659: NULL, 0, NI_NUMERICHOST) != 0)
1.84 markus 660: fatal("check_host_key: getnameinfo failed");
1.197 dtucker 661: ip = put_host_port(ntop, port);
1.84 markus 662: } else {
663: ip = xstrdup("<no hostip for proxy command>");
1.86 markus 664: }
1.206 grunk 665:
666: /*
1.88 markus 667: * Turn off check_host_ip if the connection is to localhost, via proxy
668: * command or if we don't have a hostname to compare with
669: */
1.189 dtucker 670: if (options.check_host_ip && (local ||
671: strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
1.88 markus 672: options.check_host_ip = 0;
1.86 markus 673:
674: /*
1.189 dtucker 675: * Allow the user to record the key under a different name or
676: * differentiate a non-standard port. This is useful for ssh
677: * tunneling over forwarded connections or if you run multiple
678: * sshd's on different ports on the same machine.
1.86 markus 679: */
680: if (options.host_key_alias != NULL) {
1.189 dtucker 681: host = xstrdup(options.host_key_alias);
1.86 markus 682: debug("using hostkeyalias: %s", host);
1.189 dtucker 683: } else {
1.197 dtucker 684: host = put_host_port(hostname, port);
1.84 markus 685: }
1.38 markus 686:
1.219 djm 687: retry:
688: want_cert = key_is_cert(host_key);
689: type = key_type(host_key);
690:
1.46 markus 691: /*
692: * Store the host key from the known host file in here so that we can
693: * compare it with the key for the IP address.
694: */
1.219 djm 695: file_key = key_new(key_is_cert(host_key) ? KEY_UNSPEC : host_key->type);
1.38 markus 696:
1.40 markus 697: /*
1.170 djm 698: * Check if the host key is present in the user's list of known
1.40 markus 699: * hosts or in the systemwide list.
700: */
1.85 markus 701: host_file = user_hostfile;
1.108 markus 702: host_status = check_host_in_hostfile(host_file, host, host_key,
1.118 deraadt 703: file_key, &host_line);
1.85 markus 704: if (host_status == HOST_NEW) {
705: host_file = system_hostfile;
1.108 markus 706: host_status = check_host_in_hostfile(host_file, host, host_key,
707: file_key, &host_line);
1.85 markus 708: }
1.40 markus 709: /*
710: * Also perform check for the ip address, skip the check if we are
1.219 djm 711: * localhost, looking for a certificate, or the hostname was an ip
712: * address to begin with.
1.40 markus 713: */
1.219 djm 714: if (!want_cert && options.check_host_ip) {
1.58 markus 715: Key *ip_key = key_new(host_key->type);
1.38 markus 716:
1.85 markus 717: ip_file = user_hostfile;
1.108 markus 718: ip_status = check_host_in_hostfile(ip_file, ip, host_key,
719: ip_key, &ip_line);
1.85 markus 720: if (ip_status == HOST_NEW) {
721: ip_file = system_hostfile;
1.108 markus 722: ip_status = check_host_in_hostfile(ip_file, ip,
723: host_key, ip_key, &ip_line);
1.85 markus 724: }
1.38 markus 725: if (host_status == HOST_CHANGED &&
1.58 markus 726: (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
1.38 markus 727: host_ip_differ = 1;
728:
1.58 markus 729: key_free(ip_key);
1.38 markus 730: } else
731: ip_status = host_status;
732:
1.58 markus 733: key_free(file_key);
1.38 markus 734:
735: switch (host_status) {
736: case HOST_OK:
737: /* The host is known and the key matches. */
1.219 djm 738: debug("Host '%.200s' is known and matches the %s host %s.",
739: host, type, want_cert ? "certificate" : "key");
740: debug("Found %s in %s:%d",
1.221 djm 741: want_cert ? "CA key" : "key", host_file, host_line);
1.219 djm 742: if (want_cert && !check_host_cert(hostname, host_key))
743: goto fail;
1.88 markus 744: if (options.check_host_ip && ip_status == HOST_NEW) {
1.219 djm 745: if (readonly || want_cert)
1.138 itojun 746: logit("%s host key for IP address "
1.108 markus 747: "'%.128s' not in list of known hosts.",
748: type, ip);
749: else if (!add_host_to_hostfile(user_hostfile, ip,
1.160 djm 750: host_key, options.hash_known_hosts))
1.138 itojun 751: logit("Failed to add the %s host key for IP "
1.108 markus 752: "address '%.128s' to the list of known "
753: "hosts (%.30s).", type, ip, user_hostfile);
1.88 markus 754: else
1.138 itojun 755: logit("Warning: Permanently added the %s host "
1.108 markus 756: "key for IP address '%.128s' to the list "
757: "of known hosts.", type, ip);
1.209 grunk 758: } else if (options.visual_host_key) {
1.204 grunk 759: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
760: ra = key_fingerprint(host_key, SSH_FP_MD5,
761: SSH_FP_RANDOMART);
762: logit("Host key fingerprint is %s\n%s\n", fp, ra);
763: xfree(ra);
764: xfree(fp);
1.38 markus 765: }
766: break;
767: case HOST_NEW:
1.197 dtucker 768: if (options.host_key_alias == NULL && port != 0 &&
769: port != SSH_DEFAULT_PORT) {
770: debug("checking without port identifier");
1.212 stevesk 771: if (check_host_key(hostname, hostaddr, 0, host_key,
772: ROQUIET, user_hostfile, system_hostfile) == 0) {
1.197 dtucker 773: debug("found matching key w/out port");
774: break;
775: }
776: }
1.219 djm 777: if (readonly || want_cert)
1.108 markus 778: goto fail;
1.38 markus 779: /* The host is new. */
780: if (options.strict_host_key_checking == 1) {
1.108 markus 781: /*
782: * User has requested strict host key checking. We
783: * will not add the host key automatically. The only
784: * alternative left is to abort.
785: */
786: error("No %s host key is known for %.200s and you "
787: "have requested strict checking.", type, host);
788: goto fail;
1.38 markus 789: } else if (options.strict_host_key_checking == 2) {
1.145 jakob 790: char msg1[1024], msg2[1024];
791:
792: if (show_other_keys(host, host_key))
793: snprintf(msg1, sizeof(msg1),
1.168 djm 794: "\nbut keys of different type are already"
795: " known for this host.");
1.145 jakob 796: else
797: snprintf(msg1, sizeof(msg1), ".");
1.38 markus 798: /* The default */
1.100 markus 799: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 800: ra = key_fingerprint(host_key, SSH_FP_MD5,
801: SSH_FP_RANDOMART);
1.145 jakob 802: msg2[0] = '\0';
803: if (options.verify_host_key_dns) {
1.153 jakob 804: if (matching_host_key_dns)
1.145 jakob 805: snprintf(msg2, sizeof(msg2),
806: "Matching host key fingerprint"
807: " found in DNS.\n");
808: else
809: snprintf(msg2, sizeof(msg2),
810: "No matching host key fingerprint"
811: " found in DNS.\n");
812: }
1.119 markus 813: snprintf(msg, sizeof(msg),
1.108 markus 814: "The authenticity of host '%.200s (%s)' can't be "
1.132 markus 815: "established%s\n"
1.209 grunk 816: "%s key fingerprint is %s.%s%s\n%s"
1.108 markus 817: "Are you sure you want to continue connecting "
1.132 markus 818: "(yes/no)? ",
1.209 grunk 819: host, ip, msg1, type, fp,
820: options.visual_host_key ? "\n" : "",
821: options.visual_host_key ? ra : "",
822: msg2);
1.204 grunk 823: xfree(ra);
1.100 markus 824: xfree(fp);
1.119 markus 825: if (!confirm(msg))
1.108 markus 826: goto fail;
1.38 markus 827: }
1.161 djm 828: /*
829: * If not in strict mode, add the key automatically to the
830: * local known_hosts file.
831: */
1.88 markus 832: if (options.check_host_ip && ip_status == HOST_NEW) {
1.161 djm 833: snprintf(hostline, sizeof(hostline), "%s,%s",
834: host, ip);
1.38 markus 835: hostp = hostline;
1.161 djm 836: if (options.hash_known_hosts) {
837: /* Add hash of host and IP separately */
838: r = add_host_to_hostfile(user_hostfile, host,
839: host_key, options.hash_known_hosts) &&
840: add_host_to_hostfile(user_hostfile, ip,
841: host_key, options.hash_known_hosts);
842: } else {
843: /* Add unhashed "host,ip" */
844: r = add_host_to_hostfile(user_hostfile,
845: hostline, host_key,
846: options.hash_known_hosts);
847: }
848: } else {
849: r = add_host_to_hostfile(user_hostfile, host, host_key,
850: options.hash_known_hosts);
1.38 markus 851: hostp = host;
1.161 djm 852: }
1.38 markus 853:
1.161 djm 854: if (!r)
1.138 itojun 855: logit("Failed to add the host to the list of known "
1.108 markus 856: "hosts (%.500s).", user_hostfile);
1.38 markus 857: else
1.138 itojun 858: logit("Warning: Permanently added '%.200s' (%s) to the "
1.108 markus 859: "list of known hosts.", hostp, type);
1.38 markus 860: break;
1.220 djm 861: case HOST_REVOKED:
862: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
863: error("@ WARNING: REVOKED HOST KEY DETECTED! @");
864: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
865: error("The %s host key for %s is marked as revoked.", type, host);
866: error("This could mean that a stolen key is being used to");
867: error("impersonate this host.");
868:
869: /*
870: * If strict host key checking is in use, the user will have
871: * to edit the key manually and we can only abort.
872: */
873: if (options.strict_host_key_checking) {
874: error("%s host key for %.200s was revoked and you have "
875: "requested strict checking.", type, host);
876: goto fail;
877: }
878: goto continue_unsafe;
879:
1.38 markus 880: case HOST_CHANGED:
1.219 djm 881: if (want_cert) {
882: /*
883: * This is only a debug() since it is valid to have
884: * CAs with wildcard DNS matches that don't match
885: * all hosts that one might visit.
886: */
887: debug("Host certificate authority does not "
888: "match %s in %s:%d", CA_MARKER,
889: host_file, host_line);
890: goto fail;
891: }
1.197 dtucker 892: if (readonly == ROQUIET)
893: goto fail;
1.38 markus 894: if (options.check_host_ip && host_ip_differ) {
1.158 avsm 895: char *key_msg;
1.38 markus 896: if (ip_status == HOST_NEW)
1.158 avsm 897: key_msg = "is unknown";
1.38 markus 898: else if (ip_status == HOST_OK)
1.158 avsm 899: key_msg = "is unchanged";
1.38 markus 900: else
1.158 avsm 901: key_msg = "has a different value";
1.38 markus 902: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
903: error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
904: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1.72 markus 905: error("The %s host key for %s has changed,", type, host);
1.208 ian 906: error("and the key for the corresponding IP address %s", ip);
1.158 avsm 907: error("%s. This could either mean that", key_msg);
1.38 markus 908: error("DNS SPOOFING is happening or the IP address for the host");
1.85 markus 909: error("and its host key have changed at the same time.");
1.88 markus 910: if (ip_status != HOST_NEW)
1.85 markus 911: error("Offending key for IP in %s:%d", ip_file, ip_line);
1.38 markus 912: }
913: /* The host key has changed. */
1.150 jakob 914: warn_changed_key(host_key);
1.38 markus 915: error("Add correct host key in %.100s to get rid of this message.",
1.87 markus 916: user_hostfile);
1.85 markus 917: error("Offending key in %s:%d", host_file, host_line);
1.38 markus 918:
1.40 markus 919: /*
920: * If strict host key checking is in use, the user will have
921: * to edit the key manually and we can only abort.
922: */
1.108 markus 923: if (options.strict_host_key_checking) {
924: error("%s host key for %.200s has changed and you have "
925: "requested strict checking.", type, host);
926: goto fail;
927: }
1.38 markus 928:
1.220 djm 929: continue_unsafe:
1.40 markus 930: /*
931: * If strict host key checking has not been requested, allow
1.144 djm 932: * the connection but without MITM-able authentication or
1.194 stevesk 933: * forwarding.
1.40 markus 934: */
1.38 markus 935: if (options.password_authentication) {
1.108 markus 936: error("Password authentication is disabled to avoid "
937: "man-in-the-middle attacks.");
1.38 markus 938: options.password_authentication = 0;
1.210 dtucker 939: cancelled_forwarding = 1;
1.144 djm 940: }
941: if (options.kbd_interactive_authentication) {
942: error("Keyboard-interactive authentication is disabled"
943: " to avoid man-in-the-middle attacks.");
944: options.kbd_interactive_authentication = 0;
945: options.challenge_response_authentication = 0;
1.210 dtucker 946: cancelled_forwarding = 1;
1.144 djm 947: }
948: if (options.challenge_response_authentication) {
949: error("Challenge/response authentication is disabled"
950: " to avoid man-in-the-middle attacks.");
951: options.challenge_response_authentication = 0;
1.210 dtucker 952: cancelled_forwarding = 1;
1.38 markus 953: }
954: if (options.forward_agent) {
1.108 markus 955: error("Agent forwarding is disabled to avoid "
956: "man-in-the-middle attacks.");
1.38 markus 957: options.forward_agent = 0;
1.210 dtucker 958: cancelled_forwarding = 1;
1.83 markus 959: }
960: if (options.forward_x11) {
1.108 markus 961: error("X11 forwarding is disabled to avoid "
962: "man-in-the-middle attacks.");
1.83 markus 963: options.forward_x11 = 0;
1.210 dtucker 964: cancelled_forwarding = 1;
1.83 markus 965: }
1.108 markus 966: if (options.num_local_forwards > 0 ||
967: options.num_remote_forwards > 0) {
968: error("Port forwarding is disabled to avoid "
969: "man-in-the-middle attacks.");
970: options.num_local_forwards =
1.118 deraadt 971: options.num_remote_forwards = 0;
1.210 dtucker 972: cancelled_forwarding = 1;
1.194 stevesk 973: }
974: if (options.tun_open != SSH_TUNMODE_NO) {
975: error("Tunnel forwarding is disabled to avoid "
976: "man-in-the-middle attacks.");
977: options.tun_open = SSH_TUNMODE_NO;
1.210 dtucker 978: cancelled_forwarding = 1;
1.38 markus 979: }
1.210 dtucker 980: if (options.exit_on_forward_failure && cancelled_forwarding)
981: fatal("Error: forwarding disabled due to host key "
982: "check failure");
983:
1.40 markus 984: /*
985: * XXX Should permit the user to change to use the new id.
986: * This could be done by converting the host key to an
987: * identifying sentence, tell that the host identifies itself
1.218 dtucker 988: * by that sentence, and ask the user if he/she wishes to
1.40 markus 989: * accept the authentication.
990: */
1.38 markus 991: break;
1.132 markus 992: case HOST_FOUND:
993: fatal("internal error");
994: break;
1.88 markus 995: }
996:
997: if (options.check_host_ip && host_status != HOST_CHANGED &&
998: ip_status == HOST_CHANGED) {
1.119 markus 999: snprintf(msg, sizeof(msg),
1000: "Warning: the %s host key for '%.200s' "
1001: "differs from the key for the IP address '%.128s'"
1002: "\nOffending key for IP in %s:%d",
1003: type, host, ip, ip_file, ip_line);
1004: if (host_status == HOST_OK) {
1005: len = strlen(msg);
1006: snprintf(msg + len, sizeof(msg) - len,
1007: "\nMatching host key in %s:%d",
1.125 deraadt 1008: host_file, host_line);
1.119 markus 1009: }
1.88 markus 1010: if (options.strict_host_key_checking == 1) {
1.143 djm 1011: logit("%s", msg);
1.108 markus 1012: error("Exiting, you have requested strict checking.");
1013: goto fail;
1.88 markus 1014: } else if (options.strict_host_key_checking == 2) {
1.119 markus 1015: strlcat(msg, "\nAre you sure you want "
1016: "to continue connecting (yes/no)? ", sizeof(msg));
1017: if (!confirm(msg))
1.108 markus 1018: goto fail;
1.119 markus 1019: } else {
1.143 djm 1020: logit("%s", msg);
1.88 markus 1021: }
1.38 markus 1022: }
1.82 provos 1023:
1024: xfree(ip);
1.189 dtucker 1025: xfree(host);
1.108 markus 1026: return 0;
1027:
1028: fail:
1.220 djm 1029: if (want_cert && host_status != HOST_REVOKED) {
1.219 djm 1030: /*
1031: * No matching certificate. Downgrade cert to raw key and
1032: * search normally.
1033: */
1034: debug("No matching CA found. Retry with plain key");
1035: raw_key = key_from_private(host_key);
1036: if (key_drop_cert(raw_key) != 0)
1037: fatal("Couldn't drop certificate");
1038: host_key = raw_key;
1039: goto retry;
1040: }
1041: if (raw_key != NULL)
1042: key_free(raw_key);
1.108 markus 1043: xfree(ip);
1.189 dtucker 1044: xfree(host);
1.108 markus 1045: return -1;
1046: }
1047:
1.140 jakob 1048: /* returns 0 if key verifies or -1 if key does NOT verify */
1.108 markus 1049: int
1050: verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
1051: {
1052: struct stat st;
1.153 jakob 1053: int flags = 0;
1.140 jakob 1054:
1.219 djm 1055: /* XXX certs are not yet supported for DNS */
1056: if (!key_is_cert(host_key) && options.verify_host_key_dns &&
1.153 jakob 1057: verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
1058:
1059: if (flags & DNS_VERIFY_FOUND) {
1060:
1061: if (options.verify_host_key_dns == 1 &&
1062: flags & DNS_VERIFY_MATCH &&
1063: flags & DNS_VERIFY_SECURE)
1064: return 0;
1065:
1066: if (flags & DNS_VERIFY_MATCH) {
1067: matching_host_key_dns = 1;
1068: } else {
1069: warn_changed_key(host_key);
1070: error("Update the SSHFP RR in DNS with the new "
1071: "host key to get rid of this message.");
1072: }
1.140 jakob 1073: }
1074: }
1.108 markus 1075:
1076: /* return ok if the key can be found in an old keyfile */
1077: if (stat(options.system_hostfile2, &st) == 0 ||
1078: stat(options.user_hostfile2, &st) == 0) {
1.197 dtucker 1079: if (check_host_key(host, hostaddr, options.port, host_key,
1080: RDONLY, options.user_hostfile2,
1081: options.system_hostfile2) == 0)
1.108 markus 1082: return 0;
1083: }
1.197 dtucker 1084: return check_host_key(host, hostaddr, options.port, host_key,
1085: RDRW, options.user_hostfile, options.system_hostfile);
1.51 markus 1086: }
1.70 markus 1087:
1.51 markus 1088: /*
1089: * Starts a dialog with the server, and authenticates the current user on the
1090: * server. This does not need any extra privileges. The basic connection
1091: * to the server must already have been established before this is called.
1092: * If login fails, this function prints an error and never returns.
1093: * This function does not require super-user privileges.
1094: */
1095: void
1.120 markus 1096: ssh_login(Sensitive *sensitive, const char *orighost,
1.202 djm 1097: struct sockaddr *hostaddr, struct passwd *pw, int timeout_ms)
1.51 markus 1098: {
1099: char *host, *cp;
1.70 markus 1100: char *server_user, *local_user;
1101:
1102: local_user = xstrdup(pw->pw_name);
1103: server_user = options.user ? options.user : local_user;
1.51 markus 1104:
1105: /* Convert the user-supplied hostname into all lowercase. */
1106: host = xstrdup(orighost);
1107: for (cp = host; *cp; cp++)
1108: if (isupper(*cp))
1.178 deraadt 1109: *cp = (char)tolower(*cp);
1.51 markus 1110:
1111: /* Exchange protocol version identification strings with the server. */
1.202 djm 1112: ssh_exchange_identification(timeout_ms);
1.51 markus 1113:
1114: /* Put the connection into non-blocking mode. */
1115: packet_set_nonblocking();
1116:
1117: /* key exchange */
1118: /* authenticate user */
1.59 markus 1119: if (compat20) {
1120: ssh_kex2(host, hostaddr);
1.120 markus 1121: ssh_userauth2(local_user, server_user, host, sensitive);
1.59 markus 1122: } else {
1123: ssh_kex(host, hostaddr);
1.120 markus 1124: ssh_userauth1(local_user, server_user, host, sensitive);
1.59 markus 1125: }
1.182 markus 1126: xfree(local_user);
1.97 markus 1127: }
1128:
1129: void
1130: ssh_put_password(char *password)
1131: {
1132: int size;
1133: char *padded;
1134:
1.99 deraadt 1135: if (datafellows & SSH_BUG_PASSWORDPAD) {
1.107 markus 1136: packet_put_cstring(password);
1.99 deraadt 1137: return;
1138: }
1.97 markus 1139: size = roundup(strlen(password) + 1, 32);
1.179 djm 1140: padded = xcalloc(1, size);
1.97 markus 1141: strlcpy(padded, password, size);
1142: packet_put_string(padded, size);
1143: memset(padded, 0, size);
1144: xfree(padded);
1.132 markus 1145: }
1146:
1147: static int
1148: show_key_from_file(const char *file, const char *host, int keytype)
1149: {
1150: Key *found;
1.204 grunk 1151: char *fp, *ra;
1.132 markus 1152: int line, ret;
1153:
1154: found = key_new(keytype);
1155: if ((ret = lookup_key_in_hostfile_by_type(file, host,
1156: keytype, found, &line))) {
1157: fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 1158: ra = key_fingerprint(found, SSH_FP_MD5, SSH_FP_RANDOMART);
1.138 itojun 1159: logit("WARNING: %s key found for host %s\n"
1.133 markus 1160: "in %s:%d\n"
1.204 grunk 1161: "%s key fingerprint %s.\n%s\n",
1.132 markus 1162: key_type(found), host, file, line,
1.204 grunk 1163: key_type(found), fp, ra);
1164: xfree(ra);
1.132 markus 1165: xfree(fp);
1166: }
1167: key_free(found);
1168: return (ret);
1169: }
1170:
1171: /* print all known host keys for a given host, but skip keys of given type */
1172: static int
1173: show_other_keys(const char *host, Key *key)
1174: {
1.225 djm 1175: int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, KEY_ECDSA, -1};
1.132 markus 1176: int i, found = 0;
1177:
1178: for (i = 0; type[i] != -1; i++) {
1179: if (type[i] == key->type)
1180: continue;
1181: if (type[i] != KEY_RSA1 &&
1182: show_key_from_file(options.user_hostfile2, host, type[i])) {
1183: found = 1;
1184: continue;
1185: }
1186: if (type[i] != KEY_RSA1 &&
1187: show_key_from_file(options.system_hostfile2, host, type[i])) {
1188: found = 1;
1189: continue;
1190: }
1191: if (show_key_from_file(options.user_hostfile, host, type[i])) {
1192: found = 1;
1193: continue;
1194: }
1195: if (show_key_from_file(options.system_hostfile, host, type[i])) {
1196: found = 1;
1197: continue;
1198: }
1199: debug2("no key of type %d for host %s", type[i], host);
1200: }
1201: return (found);
1.150 jakob 1202: }
1203:
1204: static void
1205: warn_changed_key(Key *host_key)
1206: {
1207: char *fp;
1.151 jakob 1208: const char *type = key_type(host_key);
1.150 jakob 1209:
1210: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1211:
1212: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1213: error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1214: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1215: error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1216: error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1217: error("It is also possible that the %s host key has just been changed.", type);
1218: error("The fingerprint for the %s key sent by the remote host is\n%s.",
1219: type, fp);
1220: error("Please contact your system administrator.");
1221:
1222: xfree(fp);
1.171 reyk 1223: }
1224:
1225: /*
1226: * Execute a local command
1227: */
1228: int
1229: ssh_local_cmd(const char *args)
1230: {
1231: char *shell;
1232: pid_t pid;
1233: int status;
1234:
1235: if (!options.permit_local_command ||
1236: args == NULL || !*args)
1237: return (1);
1238:
1.226 djm 1239: if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
1.171 reyk 1240: shell = _PATH_BSHELL;
1241:
1242: pid = fork();
1243: if (pid == 0) {
1244: debug3("Executing %s -c \"%s\"", shell, args);
1245: execl(shell, shell, "-c", args, (char *)NULL);
1246: error("Couldn't execute %s -c \"%s\": %s",
1247: shell, args, strerror(errno));
1248: _exit(1);
1249: } else if (pid == -1)
1250: fatal("fork failed: %.100s", strerror(errno));
1251: while (waitpid(pid, &status, 0) == -1)
1252: if (errno != EINTR)
1253: fatal("Couldn't wait for child: %s", strerror(errno));
1254:
1255: if (!WIFEXITED(status))
1256: return (1);
1257:
1258: return (WEXITSTATUS(status));
1.1 deraadt 1259: }
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