Annotation of src/usr.bin/ssh/sshconnect.c, Revision 1.221
1.221 ! djm 1: /* $OpenBSD: sshconnect.c,v 1.220 2010/03/04 10:36:03 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:
1.124 markus 60: /* import */
1.43 markus 61: extern Options options;
1.50 markus 62: extern char *__progname;
1.124 markus 63: extern uid_t original_real_uid;
64: extern uid_t original_effective_uid;
1.135 djm 65: extern pid_t proxy_command_pid;
1.91 markus 66:
1.132 markus 67: static int show_other_keys(const char *, Key *);
1.150 jakob 68: static void warn_changed_key(Key *);
1.132 markus 69:
1.39 deraadt 70: /*
71: * Connect to the given ssh server using a proxy command.
72: */
1.109 itojun 73: static int
1.124 markus 74: ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
1.1 deraadt 75: {
1.164 djm 76: char *command_string, *tmp;
1.38 markus 77: int pin[2], pout[2];
1.69 deraadt 78: pid_t pid;
1.201 djm 79: char *shell, strport[NI_MAXSERV];
80:
81: if ((shell = getenv("SHELL")) == NULL)
82: shell = _PATH_BSHELL;
1.38 markus 83:
84: /* Convert the port number into a string. */
1.49 markus 85: snprintf(strport, sizeof strport, "%hu", port);
1.38 markus 86:
1.135 djm 87: /*
88: * Build the final command string in the buffer by making the
89: * appropriate substitutions to the given proxy command.
90: *
1.154 djm 91: * Use "exec" to avoid "sh -c" processes on some platforms
1.135 djm 92: * (e.g. Solaris)
93: */
1.179 djm 94: xasprintf(&tmp, "exec %s", proxy_command);
1.164 djm 95: command_string = percent_expand(tmp, "h", host,
96: "p", strport, (char *)NULL);
97: xfree(tmp);
1.38 markus 98:
99: /* Create pipes for communicating with the proxy. */
100: if (pipe(pin) < 0 || pipe(pout) < 0)
101: fatal("Could not create pipes to communicate with the proxy: %.100s",
1.118 deraadt 102: strerror(errno));
1.38 markus 103:
104: debug("Executing proxy command: %.500s", command_string);
105:
106: /* Fork and execute the proxy command. */
107: if ((pid = fork()) == 0) {
108: char *argv[10];
109:
110: /* Child. Permanently give up superuser privileges. */
1.184 markus 111: permanently_drop_suid(original_real_uid);
1.38 markus 112:
113: /* Redirect stdin and stdout. */
114: close(pin[1]);
115: if (pin[0] != 0) {
116: if (dup2(pin[0], 0) < 0)
117: perror("dup2 stdin");
118: close(pin[0]);
119: }
120: close(pout[0]);
121: if (dup2(pout[1], 1) < 0)
122: perror("dup2 stdout");
123: /* Cannot be 1 because pin allocated two descriptors. */
124: close(pout[1]);
125:
126: /* Stderr is left as it is so that error messages get
127: printed on the user's terminal. */
1.201 djm 128: argv[0] = shell;
1.38 markus 129: argv[1] = "-c";
130: argv[2] = command_string;
131: argv[3] = NULL;
132:
133: /* Execute the proxy command. Note that we gave up any
134: extra privileges above. */
1.89 markus 135: execv(argv[0], argv);
136: perror(argv[0]);
1.38 markus 137: exit(1);
138: }
139: /* Parent. */
140: if (pid < 0)
141: fatal("fork failed: %.100s", strerror(errno));
1.135 djm 142: else
143: proxy_command_pid = pid; /* save pid to clean up later */
1.38 markus 144:
145: /* Close child side of the descriptors. */
146: close(pin[0]);
147: close(pout[1]);
148:
149: /* Free the command name. */
1.164 djm 150: xfree(command_string);
1.38 markus 151:
152: /* Set the connection file descriptors. */
153: packet_set_connection(pout[0], pin[1]);
1.207 dtucker 154: packet_set_timeout(options.server_alive_interval,
155: options.server_alive_count_max);
1.1 deraadt 156:
1.110 markus 157: /* Indicate OK return */
158: return 0;
1.1 deraadt 159: }
160:
1.39 deraadt 161: /*
162: * Creates a (possibly privileged) socket for use as the ssh connection.
163: */
1.109 itojun 164: static int
1.139 markus 165: ssh_create_socket(int privileged, struct addrinfo *ai)
1.1 deraadt 166: {
1.105 markus 167: int sock, gaierr;
168: struct addrinfo hints, *res;
1.1 deraadt 169:
1.40 markus 170: /*
171: * If we are running as root and want to connect to a privileged
172: * port, bind our own socket to a privileged port.
173: */
1.38 markus 174: if (privileged) {
175: int p = IPPORT_RESERVED - 1;
1.124 markus 176: PRIV_START;
1.139 markus 177: sock = rresvport_af(&p, ai->ai_family);
1.124 markus 178: PRIV_END;
1.38 markus 179: if (sock < 0)
1.139 markus 180: error("rresvport: af=%d %.100s", ai->ai_family,
181: strerror(errno));
1.55 markus 182: else
183: debug("Allocated local port %d.", p);
1.105 markus 184: return sock;
185: }
1.217 dtucker 186: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
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:
1.219 djm 571: static int
572: check_host_cert(const char *host, const Key *host_key)
573: {
574: const char *reason;
575:
576: if (key_cert_check_authority(host_key, 1, 0, host, &reason) != 0) {
577: error("%s", reason);
578: return 0;
579: }
580: if (buffer_len(&host_key->cert->constraints) != 0) {
581: error("Certificate for %s contains unsupported constraint(s)",
582: host);
583: return 0;
584: }
585: return 1;
586: }
587:
1.39 deraadt 588: /*
1.108 markus 589: * check whether the supplied host key is valid, return -1 if the key
590: * is not valid. the user_hostfile will not be updated if 'readonly' is true.
1.39 deraadt 591: */
1.197 dtucker 592: #define RDRW 0
593: #define RDONLY 1
594: #define ROQUIET 2
1.109 itojun 595: static int
1.197 dtucker 596: check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
597: Key *host_key, int readonly, const char *user_hostfile,
598: const char *system_hostfile)
1.1 deraadt 599: {
1.219 djm 600: Key *file_key, *raw_key = NULL;
601: const char *type;
1.189 dtucker 602: char *ip = NULL, *host = NULL;
1.204 grunk 603: char hostline[1000], *hostp, *fp, *ra;
1.38 markus 604: HostStatus host_status;
605: HostStatus ip_status;
1.219 djm 606: int r, want_cert, local = 0, host_ip_differ = 0;
1.49 markus 607: char ntop[NI_MAXHOST];
1.119 markus 608: char msg[1024];
1.210 dtucker 609: int len, host_line, ip_line, cancelled_forwarding = 0;
1.85 markus 610: const char *host_file = NULL, *ip_file = NULL;
1.49 markus 611:
612: /*
613: * Force accepting of the host key for loopback/localhost. The
614: * problem is that if the home directory is NFS-mounted to multiple
615: * machines, localhost will refer to a different machine in each of
616: * them, and the user will get bogus HOST_CHANGED warnings. This
617: * essentially disables host authentication for localhost; however,
618: * this is probably not a real problem.
619: */
1.70 markus 620: /** hostaddr == 0! */
1.49 markus 621: switch (hostaddr->sa_family) {
622: case AF_INET:
1.108 markus 623: local = (ntohl(((struct sockaddr_in *)hostaddr)->
1.168 djm 624: sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
1.49 markus 625: break;
626: case AF_INET6:
1.108 markus 627: local = IN6_IS_ADDR_LOOPBACK(
628: &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
1.49 markus 629: break;
630: default:
631: local = 0;
632: break;
633: }
1.111 markus 634: if (options.no_host_authentication_for_localhost == 1 && local &&
635: options.host_key_alias == NULL) {
1.88 markus 636: debug("Forcing accepting of host key for "
637: "loopback/localhost.");
1.108 markus 638: return 0;
1.49 markus 639: }
1.42 markus 640:
641: /*
1.88 markus 642: * We don't have the remote ip-address for connections
643: * using a proxy command
1.42 markus 644: */
1.84 markus 645: if (options.proxy_command == NULL) {
646: if (getnameinfo(hostaddr, hostaddr->sa_len, ntop, sizeof(ntop),
1.86 markus 647: NULL, 0, NI_NUMERICHOST) != 0)
1.84 markus 648: fatal("check_host_key: getnameinfo failed");
1.197 dtucker 649: ip = put_host_port(ntop, port);
1.84 markus 650: } else {
651: ip = xstrdup("<no hostip for proxy command>");
1.86 markus 652: }
1.206 grunk 653:
654: /*
1.88 markus 655: * Turn off check_host_ip if the connection is to localhost, via proxy
656: * command or if we don't have a hostname to compare with
657: */
1.189 dtucker 658: if (options.check_host_ip && (local ||
659: strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
1.88 markus 660: options.check_host_ip = 0;
1.86 markus 661:
662: /*
1.189 dtucker 663: * Allow the user to record the key under a different name or
664: * differentiate a non-standard port. This is useful for ssh
665: * tunneling over forwarded connections or if you run multiple
666: * sshd's on different ports on the same machine.
1.86 markus 667: */
668: if (options.host_key_alias != NULL) {
1.189 dtucker 669: host = xstrdup(options.host_key_alias);
1.86 markus 670: debug("using hostkeyalias: %s", host);
1.189 dtucker 671: } else {
1.197 dtucker 672: host = put_host_port(hostname, port);
1.84 markus 673: }
1.38 markus 674:
1.219 djm 675: retry:
676: want_cert = key_is_cert(host_key);
677: type = key_type(host_key);
678:
1.46 markus 679: /*
680: * Store the host key from the known host file in here so that we can
681: * compare it with the key for the IP address.
682: */
1.219 djm 683: file_key = key_new(key_is_cert(host_key) ? KEY_UNSPEC : host_key->type);
1.38 markus 684:
1.40 markus 685: /*
1.170 djm 686: * Check if the host key is present in the user's list of known
1.40 markus 687: * hosts or in the systemwide list.
688: */
1.85 markus 689: host_file = user_hostfile;
1.108 markus 690: host_status = check_host_in_hostfile(host_file, host, host_key,
1.118 deraadt 691: file_key, &host_line);
1.85 markus 692: if (host_status == HOST_NEW) {
693: host_file = system_hostfile;
1.108 markus 694: host_status = check_host_in_hostfile(host_file, host, host_key,
695: file_key, &host_line);
1.85 markus 696: }
1.40 markus 697: /*
698: * Also perform check for the ip address, skip the check if we are
1.219 djm 699: * localhost, looking for a certificate, or the hostname was an ip
700: * address to begin with.
1.40 markus 701: */
1.219 djm 702: if (!want_cert && options.check_host_ip) {
1.58 markus 703: Key *ip_key = key_new(host_key->type);
1.38 markus 704:
1.85 markus 705: ip_file = user_hostfile;
1.108 markus 706: ip_status = check_host_in_hostfile(ip_file, ip, host_key,
707: ip_key, &ip_line);
1.85 markus 708: if (ip_status == HOST_NEW) {
709: ip_file = system_hostfile;
1.108 markus 710: ip_status = check_host_in_hostfile(ip_file, ip,
711: host_key, ip_key, &ip_line);
1.85 markus 712: }
1.38 markus 713: if (host_status == HOST_CHANGED &&
1.58 markus 714: (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
1.38 markus 715: host_ip_differ = 1;
716:
1.58 markus 717: key_free(ip_key);
1.38 markus 718: } else
719: ip_status = host_status;
720:
1.58 markus 721: key_free(file_key);
1.38 markus 722:
723: switch (host_status) {
724: case HOST_OK:
725: /* The host is known and the key matches. */
1.219 djm 726: debug("Host '%.200s' is known and matches the %s host %s.",
727: host, type, want_cert ? "certificate" : "key");
728: debug("Found %s in %s:%d",
1.221 ! djm 729: want_cert ? "CA key" : "key", host_file, host_line);
1.219 djm 730: if (want_cert && !check_host_cert(hostname, host_key))
731: goto fail;
1.88 markus 732: if (options.check_host_ip && ip_status == HOST_NEW) {
1.219 djm 733: if (readonly || want_cert)
1.138 itojun 734: logit("%s host key for IP address "
1.108 markus 735: "'%.128s' not in list of known hosts.",
736: type, ip);
737: else if (!add_host_to_hostfile(user_hostfile, ip,
1.160 djm 738: host_key, options.hash_known_hosts))
1.138 itojun 739: logit("Failed to add the %s host key for IP "
1.108 markus 740: "address '%.128s' to the list of known "
741: "hosts (%.30s).", type, ip, user_hostfile);
1.88 markus 742: else
1.138 itojun 743: logit("Warning: Permanently added the %s host "
1.108 markus 744: "key for IP address '%.128s' to the list "
745: "of known hosts.", type, ip);
1.209 grunk 746: } else if (options.visual_host_key) {
1.204 grunk 747: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
748: ra = key_fingerprint(host_key, SSH_FP_MD5,
749: SSH_FP_RANDOMART);
750: logit("Host key fingerprint is %s\n%s\n", fp, ra);
751: xfree(ra);
752: xfree(fp);
1.38 markus 753: }
754: break;
755: case HOST_NEW:
1.197 dtucker 756: if (options.host_key_alias == NULL && port != 0 &&
757: port != SSH_DEFAULT_PORT) {
758: debug("checking without port identifier");
1.212 stevesk 759: if (check_host_key(hostname, hostaddr, 0, host_key,
760: ROQUIET, user_hostfile, system_hostfile) == 0) {
1.197 dtucker 761: debug("found matching key w/out port");
762: break;
763: }
764: }
1.219 djm 765: if (readonly || want_cert)
1.108 markus 766: goto fail;
1.38 markus 767: /* The host is new. */
768: if (options.strict_host_key_checking == 1) {
1.108 markus 769: /*
770: * User has requested strict host key checking. We
771: * will not add the host key automatically. The only
772: * alternative left is to abort.
773: */
774: error("No %s host key is known for %.200s and you "
775: "have requested strict checking.", type, host);
776: goto fail;
1.38 markus 777: } else if (options.strict_host_key_checking == 2) {
1.145 jakob 778: char msg1[1024], msg2[1024];
779:
780: if (show_other_keys(host, host_key))
781: snprintf(msg1, sizeof(msg1),
1.168 djm 782: "\nbut keys of different type are already"
783: " known for this host.");
1.145 jakob 784: else
785: snprintf(msg1, sizeof(msg1), ".");
1.38 markus 786: /* The default */
1.100 markus 787: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 788: ra = key_fingerprint(host_key, SSH_FP_MD5,
789: SSH_FP_RANDOMART);
1.145 jakob 790: msg2[0] = '\0';
791: if (options.verify_host_key_dns) {
1.153 jakob 792: if (matching_host_key_dns)
1.145 jakob 793: snprintf(msg2, sizeof(msg2),
794: "Matching host key fingerprint"
795: " found in DNS.\n");
796: else
797: snprintf(msg2, sizeof(msg2),
798: "No matching host key fingerprint"
799: " found in DNS.\n");
800: }
1.119 markus 801: snprintf(msg, sizeof(msg),
1.108 markus 802: "The authenticity of host '%.200s (%s)' can't be "
1.132 markus 803: "established%s\n"
1.209 grunk 804: "%s key fingerprint is %s.%s%s\n%s"
1.108 markus 805: "Are you sure you want to continue connecting "
1.132 markus 806: "(yes/no)? ",
1.209 grunk 807: host, ip, msg1, type, fp,
808: options.visual_host_key ? "\n" : "",
809: options.visual_host_key ? ra : "",
810: msg2);
1.204 grunk 811: xfree(ra);
1.100 markus 812: xfree(fp);
1.119 markus 813: if (!confirm(msg))
1.108 markus 814: goto fail;
1.38 markus 815: }
1.161 djm 816: /*
817: * If not in strict mode, add the key automatically to the
818: * local known_hosts file.
819: */
1.88 markus 820: if (options.check_host_ip && ip_status == HOST_NEW) {
1.161 djm 821: snprintf(hostline, sizeof(hostline), "%s,%s",
822: host, ip);
1.38 markus 823: hostp = hostline;
1.161 djm 824: if (options.hash_known_hosts) {
825: /* Add hash of host and IP separately */
826: r = add_host_to_hostfile(user_hostfile, host,
827: host_key, options.hash_known_hosts) &&
828: add_host_to_hostfile(user_hostfile, ip,
829: host_key, options.hash_known_hosts);
830: } else {
831: /* Add unhashed "host,ip" */
832: r = add_host_to_hostfile(user_hostfile,
833: hostline, host_key,
834: options.hash_known_hosts);
835: }
836: } else {
837: r = add_host_to_hostfile(user_hostfile, host, host_key,
838: options.hash_known_hosts);
1.38 markus 839: hostp = host;
1.161 djm 840: }
1.38 markus 841:
1.161 djm 842: if (!r)
1.138 itojun 843: logit("Failed to add the host to the list of known "
1.108 markus 844: "hosts (%.500s).", user_hostfile);
1.38 markus 845: else
1.138 itojun 846: logit("Warning: Permanently added '%.200s' (%s) to the "
1.108 markus 847: "list of known hosts.", hostp, type);
1.38 markus 848: break;
1.220 djm 849: case HOST_REVOKED:
850: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
851: error("@ WARNING: REVOKED HOST KEY DETECTED! @");
852: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
853: error("The %s host key for %s is marked as revoked.", type, host);
854: error("This could mean that a stolen key is being used to");
855: error("impersonate this host.");
856:
857: /*
858: * If strict host key checking is in use, the user will have
859: * to edit the key manually and we can only abort.
860: */
861: if (options.strict_host_key_checking) {
862: error("%s host key for %.200s was revoked and you have "
863: "requested strict checking.", type, host);
864: goto fail;
865: }
866: goto continue_unsafe;
867:
1.38 markus 868: case HOST_CHANGED:
1.219 djm 869: if (want_cert) {
870: /*
871: * This is only a debug() since it is valid to have
872: * CAs with wildcard DNS matches that don't match
873: * all hosts that one might visit.
874: */
875: debug("Host certificate authority does not "
876: "match %s in %s:%d", CA_MARKER,
877: host_file, host_line);
878: goto fail;
879: }
1.197 dtucker 880: if (readonly == ROQUIET)
881: goto fail;
1.38 markus 882: if (options.check_host_ip && host_ip_differ) {
1.158 avsm 883: char *key_msg;
1.38 markus 884: if (ip_status == HOST_NEW)
1.158 avsm 885: key_msg = "is unknown";
1.38 markus 886: else if (ip_status == HOST_OK)
1.158 avsm 887: key_msg = "is unchanged";
1.38 markus 888: else
1.158 avsm 889: key_msg = "has a different value";
1.38 markus 890: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
891: error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
892: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1.72 markus 893: error("The %s host key for %s has changed,", type, host);
1.208 ian 894: error("and the key for the corresponding IP address %s", ip);
1.158 avsm 895: error("%s. This could either mean that", key_msg);
1.38 markus 896: error("DNS SPOOFING is happening or the IP address for the host");
1.85 markus 897: error("and its host key have changed at the same time.");
1.88 markus 898: if (ip_status != HOST_NEW)
1.85 markus 899: error("Offending key for IP in %s:%d", ip_file, ip_line);
1.38 markus 900: }
901: /* The host key has changed. */
1.150 jakob 902: warn_changed_key(host_key);
1.38 markus 903: error("Add correct host key in %.100s to get rid of this message.",
1.87 markus 904: user_hostfile);
1.85 markus 905: error("Offending key in %s:%d", host_file, host_line);
1.38 markus 906:
1.40 markus 907: /*
908: * If strict host key checking is in use, the user will have
909: * to edit the key manually and we can only abort.
910: */
1.108 markus 911: if (options.strict_host_key_checking) {
912: error("%s host key for %.200s has changed and you have "
913: "requested strict checking.", type, host);
914: goto fail;
915: }
1.38 markus 916:
1.220 djm 917: continue_unsafe:
1.40 markus 918: /*
919: * If strict host key checking has not been requested, allow
1.144 djm 920: * the connection but without MITM-able authentication or
1.194 stevesk 921: * forwarding.
1.40 markus 922: */
1.38 markus 923: if (options.password_authentication) {
1.108 markus 924: error("Password authentication is disabled to avoid "
925: "man-in-the-middle attacks.");
1.38 markus 926: options.password_authentication = 0;
1.210 dtucker 927: cancelled_forwarding = 1;
1.144 djm 928: }
929: if (options.kbd_interactive_authentication) {
930: error("Keyboard-interactive authentication is disabled"
931: " to avoid man-in-the-middle attacks.");
932: options.kbd_interactive_authentication = 0;
933: options.challenge_response_authentication = 0;
1.210 dtucker 934: cancelled_forwarding = 1;
1.144 djm 935: }
936: if (options.challenge_response_authentication) {
937: error("Challenge/response authentication is disabled"
938: " to avoid man-in-the-middle attacks.");
939: options.challenge_response_authentication = 0;
1.210 dtucker 940: cancelled_forwarding = 1;
1.38 markus 941: }
942: if (options.forward_agent) {
1.108 markus 943: error("Agent forwarding is disabled to avoid "
944: "man-in-the-middle attacks.");
1.38 markus 945: options.forward_agent = 0;
1.210 dtucker 946: cancelled_forwarding = 1;
1.83 markus 947: }
948: if (options.forward_x11) {
1.108 markus 949: error("X11 forwarding is disabled to avoid "
950: "man-in-the-middle attacks.");
1.83 markus 951: options.forward_x11 = 0;
1.210 dtucker 952: cancelled_forwarding = 1;
1.83 markus 953: }
1.108 markus 954: if (options.num_local_forwards > 0 ||
955: options.num_remote_forwards > 0) {
956: error("Port forwarding is disabled to avoid "
957: "man-in-the-middle attacks.");
958: options.num_local_forwards =
1.118 deraadt 959: options.num_remote_forwards = 0;
1.210 dtucker 960: cancelled_forwarding = 1;
1.194 stevesk 961: }
962: if (options.tun_open != SSH_TUNMODE_NO) {
963: error("Tunnel forwarding is disabled to avoid "
964: "man-in-the-middle attacks.");
965: options.tun_open = SSH_TUNMODE_NO;
1.210 dtucker 966: cancelled_forwarding = 1;
1.38 markus 967: }
1.210 dtucker 968: if (options.exit_on_forward_failure && cancelled_forwarding)
969: fatal("Error: forwarding disabled due to host key "
970: "check failure");
971:
1.40 markus 972: /*
973: * XXX Should permit the user to change to use the new id.
974: * This could be done by converting the host key to an
975: * identifying sentence, tell that the host identifies itself
1.218 dtucker 976: * by that sentence, and ask the user if he/she wishes to
1.40 markus 977: * accept the authentication.
978: */
1.38 markus 979: break;
1.132 markus 980: case HOST_FOUND:
981: fatal("internal error");
982: break;
1.88 markus 983: }
984:
985: if (options.check_host_ip && host_status != HOST_CHANGED &&
986: ip_status == HOST_CHANGED) {
1.119 markus 987: snprintf(msg, sizeof(msg),
988: "Warning: the %s host key for '%.200s' "
989: "differs from the key for the IP address '%.128s'"
990: "\nOffending key for IP in %s:%d",
991: type, host, ip, ip_file, ip_line);
992: if (host_status == HOST_OK) {
993: len = strlen(msg);
994: snprintf(msg + len, sizeof(msg) - len,
995: "\nMatching host key in %s:%d",
1.125 deraadt 996: host_file, host_line);
1.119 markus 997: }
1.88 markus 998: if (options.strict_host_key_checking == 1) {
1.143 djm 999: logit("%s", msg);
1.108 markus 1000: error("Exiting, you have requested strict checking.");
1001: goto fail;
1.88 markus 1002: } else if (options.strict_host_key_checking == 2) {
1.119 markus 1003: strlcat(msg, "\nAre you sure you want "
1004: "to continue connecting (yes/no)? ", sizeof(msg));
1005: if (!confirm(msg))
1.108 markus 1006: goto fail;
1.119 markus 1007: } else {
1.143 djm 1008: logit("%s", msg);
1.88 markus 1009: }
1.38 markus 1010: }
1.82 provos 1011:
1012: xfree(ip);
1.189 dtucker 1013: xfree(host);
1.108 markus 1014: return 0;
1015:
1016: fail:
1.220 djm 1017: if (want_cert && host_status != HOST_REVOKED) {
1.219 djm 1018: /*
1019: * No matching certificate. Downgrade cert to raw key and
1020: * search normally.
1021: */
1022: debug("No matching CA found. Retry with plain key");
1023: raw_key = key_from_private(host_key);
1024: if (key_drop_cert(raw_key) != 0)
1025: fatal("Couldn't drop certificate");
1026: host_key = raw_key;
1027: goto retry;
1028: }
1029: if (raw_key != NULL)
1030: key_free(raw_key);
1.108 markus 1031: xfree(ip);
1.189 dtucker 1032: xfree(host);
1.108 markus 1033: return -1;
1034: }
1035:
1.140 jakob 1036: /* returns 0 if key verifies or -1 if key does NOT verify */
1.108 markus 1037: int
1038: verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
1039: {
1040: struct stat st;
1.153 jakob 1041: int flags = 0;
1.140 jakob 1042:
1.219 djm 1043: /* XXX certs are not yet supported for DNS */
1044: if (!key_is_cert(host_key) && options.verify_host_key_dns &&
1.153 jakob 1045: verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
1046:
1047: if (flags & DNS_VERIFY_FOUND) {
1048:
1049: if (options.verify_host_key_dns == 1 &&
1050: flags & DNS_VERIFY_MATCH &&
1051: flags & DNS_VERIFY_SECURE)
1052: return 0;
1053:
1054: if (flags & DNS_VERIFY_MATCH) {
1055: matching_host_key_dns = 1;
1056: } else {
1057: warn_changed_key(host_key);
1058: error("Update the SSHFP RR in DNS with the new "
1059: "host key to get rid of this message.");
1060: }
1.140 jakob 1061: }
1062: }
1.108 markus 1063:
1064: /* return ok if the key can be found in an old keyfile */
1065: if (stat(options.system_hostfile2, &st) == 0 ||
1066: stat(options.user_hostfile2, &st) == 0) {
1.197 dtucker 1067: if (check_host_key(host, hostaddr, options.port, host_key,
1068: RDONLY, options.user_hostfile2,
1069: options.system_hostfile2) == 0)
1.108 markus 1070: return 0;
1071: }
1.197 dtucker 1072: return check_host_key(host, hostaddr, options.port, host_key,
1073: RDRW, options.user_hostfile, options.system_hostfile);
1.51 markus 1074: }
1.70 markus 1075:
1.51 markus 1076: /*
1077: * Starts a dialog with the server, and authenticates the current user on the
1078: * server. This does not need any extra privileges. The basic connection
1079: * to the server must already have been established before this is called.
1080: * If login fails, this function prints an error and never returns.
1081: * This function does not require super-user privileges.
1082: */
1083: void
1.120 markus 1084: ssh_login(Sensitive *sensitive, const char *orighost,
1.202 djm 1085: struct sockaddr *hostaddr, struct passwd *pw, int timeout_ms)
1.51 markus 1086: {
1087: char *host, *cp;
1.70 markus 1088: char *server_user, *local_user;
1089:
1090: local_user = xstrdup(pw->pw_name);
1091: server_user = options.user ? options.user : local_user;
1.51 markus 1092:
1093: /* Convert the user-supplied hostname into all lowercase. */
1094: host = xstrdup(orighost);
1095: for (cp = host; *cp; cp++)
1096: if (isupper(*cp))
1.178 deraadt 1097: *cp = (char)tolower(*cp);
1.51 markus 1098:
1099: /* Exchange protocol version identification strings with the server. */
1.202 djm 1100: ssh_exchange_identification(timeout_ms);
1.51 markus 1101:
1102: /* Put the connection into non-blocking mode. */
1103: packet_set_nonblocking();
1104:
1105: /* key exchange */
1106: /* authenticate user */
1.59 markus 1107: if (compat20) {
1108: ssh_kex2(host, hostaddr);
1.120 markus 1109: ssh_userauth2(local_user, server_user, host, sensitive);
1.59 markus 1110: } else {
1111: ssh_kex(host, hostaddr);
1.120 markus 1112: ssh_userauth1(local_user, server_user, host, sensitive);
1.59 markus 1113: }
1.182 markus 1114: xfree(local_user);
1.97 markus 1115: }
1116:
1117: void
1118: ssh_put_password(char *password)
1119: {
1120: int size;
1121: char *padded;
1122:
1.99 deraadt 1123: if (datafellows & SSH_BUG_PASSWORDPAD) {
1.107 markus 1124: packet_put_cstring(password);
1.99 deraadt 1125: return;
1126: }
1.97 markus 1127: size = roundup(strlen(password) + 1, 32);
1.179 djm 1128: padded = xcalloc(1, size);
1.97 markus 1129: strlcpy(padded, password, size);
1130: packet_put_string(padded, size);
1131: memset(padded, 0, size);
1132: xfree(padded);
1.132 markus 1133: }
1134:
1135: static int
1136: show_key_from_file(const char *file, const char *host, int keytype)
1137: {
1138: Key *found;
1.204 grunk 1139: char *fp, *ra;
1.132 markus 1140: int line, ret;
1141:
1142: found = key_new(keytype);
1143: if ((ret = lookup_key_in_hostfile_by_type(file, host,
1144: keytype, found, &line))) {
1145: fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
1.204 grunk 1146: ra = key_fingerprint(found, SSH_FP_MD5, SSH_FP_RANDOMART);
1.138 itojun 1147: logit("WARNING: %s key found for host %s\n"
1.133 markus 1148: "in %s:%d\n"
1.204 grunk 1149: "%s key fingerprint %s.\n%s\n",
1.132 markus 1150: key_type(found), host, file, line,
1.204 grunk 1151: key_type(found), fp, ra);
1152: xfree(ra);
1.132 markus 1153: xfree(fp);
1154: }
1155: key_free(found);
1156: return (ret);
1157: }
1158:
1159: /* print all known host keys for a given host, but skip keys of given type */
1160: static int
1161: show_other_keys(const char *host, Key *key)
1162: {
1163: int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1};
1164: int i, found = 0;
1165:
1166: for (i = 0; type[i] != -1; i++) {
1167: if (type[i] == key->type)
1168: continue;
1169: if (type[i] != KEY_RSA1 &&
1170: show_key_from_file(options.user_hostfile2, host, type[i])) {
1171: found = 1;
1172: continue;
1173: }
1174: if (type[i] != KEY_RSA1 &&
1175: show_key_from_file(options.system_hostfile2, host, type[i])) {
1176: found = 1;
1177: continue;
1178: }
1179: if (show_key_from_file(options.user_hostfile, host, type[i])) {
1180: found = 1;
1181: continue;
1182: }
1183: if (show_key_from_file(options.system_hostfile, host, type[i])) {
1184: found = 1;
1185: continue;
1186: }
1187: debug2("no key of type %d for host %s", type[i], host);
1188: }
1189: return (found);
1.150 jakob 1190: }
1191:
1192: static void
1193: warn_changed_key(Key *host_key)
1194: {
1195: char *fp;
1.151 jakob 1196: const char *type = key_type(host_key);
1.150 jakob 1197:
1198: fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1199:
1200: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1201: error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1202: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1203: error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1204: error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1205: error("It is also possible that the %s host key has just been changed.", type);
1206: error("The fingerprint for the %s key sent by the remote host is\n%s.",
1207: type, fp);
1208: error("Please contact your system administrator.");
1209:
1210: xfree(fp);
1.171 reyk 1211: }
1212:
1213: /*
1214: * Execute a local command
1215: */
1216: int
1217: ssh_local_cmd(const char *args)
1218: {
1219: char *shell;
1220: pid_t pid;
1221: int status;
1222:
1223: if (!options.permit_local_command ||
1224: args == NULL || !*args)
1225: return (1);
1226:
1227: if ((shell = getenv("SHELL")) == NULL)
1228: shell = _PATH_BSHELL;
1229:
1230: pid = fork();
1231: if (pid == 0) {
1232: debug3("Executing %s -c \"%s\"", shell, args);
1233: execl(shell, shell, "-c", args, (char *)NULL);
1234: error("Couldn't execute %s -c \"%s\": %s",
1235: shell, args, strerror(errno));
1236: _exit(1);
1237: } else if (pid == -1)
1238: fatal("fork failed: %.100s", strerror(errno));
1239: while (waitpid(pid, &status, 0) == -1)
1240: if (errno != EINTR)
1241: fatal("Couldn't wait for child: %s", strerror(errno));
1242:
1243: if (!WIFEXITED(status))
1244: return (1);
1245:
1246: return (WEXITSTATUS(status));
1.1 deraadt 1247: }