blob: 9de52224d34c3c87c2f0645cd260606f8ca6d80e [file] [log] [blame]
Damien Miller1aed65e2010-03-04 21:53:35 +11001/* $OpenBSD: sshconnect.c,v 1.220 2010/03/04 10:36:03 djm Exp $ */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002/*
Damien Miller95def091999-11-25 00:26:21 +11003 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11006 * Code to connect to a remote host, and to perform the client side of the
7 * login (authentication) dialog.
Damien Millere4340be2000-09-16 13:29:08 +11008 *
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".
Damien Miller95def091999-11-25 00:26:21 +110014 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100015
16#include "includes.h"
Damien Miller9cf6d072006-03-15 11:29:24 +110017
18#include <sys/types.h>
19#include <sys/wait.h>
Damien Millerf17883e2006-03-15 11:45:54 +110020#include <sys/stat.h>
Damien Miller8ec8c3e2006-07-10 20:35:38 +100021#include <sys/socket.h>
Damien Miller9aec9192006-08-05 10:57:45 +100022#ifdef HAVE_SYS_TIME_H
23# include <sys/time.h>
24#endif
Damien Miller8ec8c3e2006-07-10 20:35:38 +100025
26#include <netinet/in.h>
Darren Tucker46aa3e02006-09-02 15:32:40 +100027#include <arpa/inet.h>
Damien Miller03e20032006-03-15 11:16:59 +110028
Damien Millerc7b06362006-03-15 11:53:45 +110029#include <ctype.h>
Darren Tucker39972492006-07-12 22:22:46 +100030#include <errno.h>
Darren Tucker6e7fe1c2010-01-08 17:07:22 +110031#include <fcntl.h>
Damien Millerb8fe89c2006-07-24 14:51:00 +100032#include <netdb.h>
Damien Miller6645e7a2006-03-15 14:42:54 +110033#ifdef HAVE_PATHS_H
Damien Miller03e20032006-03-15 11:16:59 +110034#include <paths.h>
Damien Miller6645e7a2006-03-15 14:42:54 +110035#endif
Damien Miller9f2abc42006-07-10 20:53:08 +100036#include <pwd.h>
Damien Millerded319c2006-09-01 15:38:36 +100037#include <stdarg.h>
Damien Millera7a73ee2006-08-05 11:37:59 +100038#include <stdio.h>
Damien Millere7a1e5c2006-08-05 11:34:19 +100039#include <stdlib.h>
Damien Millere3476ed2006-07-24 14:13:33 +100040#include <string.h>
Damien Millere6b3b612006-07-24 14:01:23 +100041#include <unistd.h>
Damien Millerd4a8b7e1999-10-27 13:42:43 +100042
Damien Millerd4a8b7e1999-10-27 13:42:43 +100043#include "xmalloc.h"
Damien Millerd7834352006-08-05 12:39:39 +100044#include "key.h"
45#include "hostfile.h"
46#include "ssh.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100047#include "rsa.h"
Damien Miller1383bd82000-04-06 12:32:37 +100048#include "buffer.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100049#include "packet.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100050#include "uidswap.h"
51#include "compat.h"
Damien Miller450a7a12000-03-26 13:04:51 +100052#include "key.h"
Damien Millereba71ba2000-04-29 23:57:08 +100053#include "sshconnect.h"
Damien Miller450a7a12000-03-26 13:04:51 +100054#include "hostfile.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000055#include "log.h"
56#include "readconf.h"
57#include "atomicio.h"
58#include "misc.h"
Damien Miller37876e92003-05-15 10:19:46 +100059#include "dns.h"
Darren Tuckerc5564e12009-06-21 18:53:53 +100060#include "roaming.h"
Damien Miller0a80ca12010-02-27 07:55:05 +110061#include "ssh2.h"
Damien Millerb7576772006-07-10 20:23:39 +100062#include "version.h"
Damien Miller37876e92003-05-15 10:19:46 +100063
Damien Millereba71ba2000-04-29 23:57:08 +100064char *client_version_string = NULL;
65char *server_version_string = NULL;
Damien Miller1383bd82000-04-06 12:32:37 +100066
Damien Millerc1af1d52005-11-05 15:08:57 +110067static int matching_host_key_dns = 0;
Damien Miller7392ae62003-06-11 22:05:25 +100068
Ben Lindstromf9c48842002-06-11 16:37:51 +000069/* import */
Damien Milleraae6c611999-12-06 11:47:28 +110070extern Options options;
Damien Miller34132e52000-01-14 15:45:46 +110071extern char *__progname;
Ben Lindstromf9c48842002-06-11 16:37:51 +000072extern uid_t original_real_uid;
73extern uid_t original_effective_uid;
Damien Miller8c4e18a2002-09-19 12:05:02 +100074extern pid_t proxy_command_pid;
Damien Milleraae6c611999-12-06 11:47:28 +110075
Ben Lindstrom3ed66402002-08-01 01:21:56 +000076static int show_other_keys(const char *, Key *);
Damien Miller5a388972003-11-17 21:10:47 +110077static void warn_changed_key(Key *);
Ben Lindstrom3ed66402002-08-01 01:21:56 +000078
Damien Miller95def091999-11-25 00:26:21 +110079/*
80 * Connect to the given ssh server using a proxy command.
81 */
Ben Lindstrombba81212001-06-25 05:01:22 +000082static int
Ben Lindstromf9c48842002-06-11 16:37:51 +000083ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
Damien Millerd4a8b7e1999-10-27 13:42:43 +100084{
Damien Miller6476cad2005-06-16 13:18:34 +100085 char *command_string, *tmp;
Damien Miller95def091999-11-25 00:26:21 +110086 int pin[2], pout[2];
Damien Miller166fca82000-04-20 07:42:21 +100087 pid_t pid;
Damien Miller1d824ab2007-09-17 11:58:04 +100088 char *shell, strport[NI_MAXSERV];
89
90 if ((shell = getenv("SHELL")) == NULL)
91 shell = _PATH_BSHELL;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100092
Damien Miller95def091999-11-25 00:26:21 +110093 /* Convert the port number into a string. */
Damien Miller34132e52000-01-14 15:45:46 +110094 snprintf(strport, sizeof strport, "%hu", port);
Damien Millerd4a8b7e1999-10-27 13:42:43 +100095
Damien Miller8c4e18a2002-09-19 12:05:02 +100096 /*
97 * Build the final command string in the buffer by making the
98 * appropriate substitutions to the given proxy command.
99 *
Damien Millera8e06ce2003-11-21 23:48:55 +1100100 * Use "exec" to avoid "sh -c" processes on some platforms
Damien Miller8c4e18a2002-09-19 12:05:02 +1000101 * (e.g. Solaris)
102 */
Damien Miller07d86be2006-03-26 14:19:21 +1100103 xasprintf(&tmp, "exec %s", proxy_command);
Damien Miller6476cad2005-06-16 13:18:34 +1000104 command_string = percent_expand(tmp, "h", host,
105 "p", strport, (char *)NULL);
106 xfree(tmp);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000107
Damien Miller95def091999-11-25 00:26:21 +1100108 /* Create pipes for communicating with the proxy. */
109 if (pipe(pin) < 0 || pipe(pout) < 0)
110 fatal("Could not create pipes to communicate with the proxy: %.100s",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100111 strerror(errno));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000112
Damien Miller95def091999-11-25 00:26:21 +1100113 debug("Executing proxy command: %.500s", command_string);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000114
Damien Miller95def091999-11-25 00:26:21 +1100115 /* Fork and execute the proxy command. */
116 if ((pid = fork()) == 0) {
117 char *argv[10];
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000118
Damien Miller95def091999-11-25 00:26:21 +1100119 /* Child. Permanently give up superuser privileges. */
Damien Miller2e5fe882006-06-13 13:10:00 +1000120 permanently_drop_suid(original_real_uid);
Damien Miller95def091999-11-25 00:26:21 +1100121
122 /* Redirect stdin and stdout. */
123 close(pin[1]);
124 if (pin[0] != 0) {
125 if (dup2(pin[0], 0) < 0)
126 perror("dup2 stdin");
127 close(pin[0]);
128 }
129 close(pout[0]);
130 if (dup2(pout[1], 1) < 0)
131 perror("dup2 stdout");
132 /* Cannot be 1 because pin allocated two descriptors. */
133 close(pout[1]);
134
135 /* Stderr is left as it is so that error messages get
136 printed on the user's terminal. */
Damien Miller1d824ab2007-09-17 11:58:04 +1000137 argv[0] = shell;
Damien Miller95def091999-11-25 00:26:21 +1100138 argv[1] = "-c";
139 argv[2] = command_string;
140 argv[3] = NULL;
141
142 /* Execute the proxy command. Note that we gave up any
143 extra privileges above. */
Kevin Stevesfcd5d602001-01-07 11:45:22 +0000144 execv(argv[0], argv);
145 perror(argv[0]);
Damien Miller95def091999-11-25 00:26:21 +1100146 exit(1);
147 }
148 /* Parent. */
149 if (pid < 0)
150 fatal("fork failed: %.100s", strerror(errno));
Damien Miller8c4e18a2002-09-19 12:05:02 +1000151 else
152 proxy_command_pid = pid; /* save pid to clean up later */
Damien Miller95def091999-11-25 00:26:21 +1100153
154 /* Close child side of the descriptors. */
155 close(pin[0]);
156 close(pout[1]);
157
158 /* Free the command name. */
Damien Miller6476cad2005-06-16 13:18:34 +1000159 xfree(command_string);
Damien Miller95def091999-11-25 00:26:21 +1100160
161 /* Set the connection file descriptors. */
162 packet_set_connection(pout[0], pin[1]);
Darren Tucker3fc464e2008-06-13 06:42:45 +1000163 packet_set_timeout(options.server_alive_interval,
164 options.server_alive_count_max);
Damien Miller95def091999-11-25 00:26:21 +1100165
Ben Lindstromf9cedb92001-08-06 21:07:11 +0000166 /* Indicate OK return */
167 return 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000168}
169
Damien Miller95def091999-11-25 00:26:21 +1100170/*
171 * Creates a (possibly privileged) socket for use as the ssh connection.
172 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000173static int
Damien Miller2372ace2003-05-14 13:42:23 +1000174ssh_create_socket(int privileged, struct addrinfo *ai)
Damien Miller95def091999-11-25 00:26:21 +1100175{
Ben Lindstrome0f88042001-04-30 13:06:24 +0000176 int sock, gaierr;
177 struct addrinfo hints, *res;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000178
Damien Miller5428f641999-11-25 11:54:57 +1100179 /*
180 * If we are running as root and want to connect to a privileged
181 * port, bind our own socket to a privileged port.
182 */
Damien Miller95def091999-11-25 00:26:21 +1100183 if (privileged) {
184 int p = IPPORT_RESERVED - 1;
Ben Lindstromf9c48842002-06-11 16:37:51 +0000185 PRIV_START;
Damien Miller2372ace2003-05-14 13:42:23 +1000186 sock = rresvport_af(&p, ai->ai_family);
Ben Lindstromf9c48842002-06-11 16:37:51 +0000187 PRIV_END;
Damien Miller95def091999-11-25 00:26:21 +1100188 if (sock < 0)
Damien Miller2372ace2003-05-14 13:42:23 +1000189 error("rresvport: af=%d %.100s", ai->ai_family,
190 strerror(errno));
Damien Miller98c7ad62000-03-09 21:27:49 +1100191 else
192 debug("Allocated local port %d.", p);
Ben Lindstrome0f88042001-04-30 13:06:24 +0000193 return sock;
Damien Miller95def091999-11-25 00:26:21 +1100194 }
Darren Tucker7bd98e72010-01-10 10:31:12 +1100195 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
Darren Tucker6e7fe1c2010-01-08 17:07:22 +1100196 if (sock < 0) {
Ben Lindstrome0f88042001-04-30 13:06:24 +0000197 error("socket: %.100s", strerror(errno));
Darren Tucker6e7fe1c2010-01-08 17:07:22 +1100198 return -1;
199 }
200 fcntl(sock, F_SETFD, FD_CLOEXEC);
Ben Lindstrome0f88042001-04-30 13:06:24 +0000201
202 /* Bind the socket to an alternative local IP address */
203 if (options.bind_address == NULL)
204 return sock;
205
206 memset(&hints, 0, sizeof(hints));
Damien Miller2372ace2003-05-14 13:42:23 +1000207 hints.ai_family = ai->ai_family;
208 hints.ai_socktype = ai->ai_socktype;
209 hints.ai_protocol = ai->ai_protocol;
Ben Lindstrome0f88042001-04-30 13:06:24 +0000210 hints.ai_flags = AI_PASSIVE;
Darren Tucker30ac73b2008-06-13 04:46:45 +1000211 gaierr = getaddrinfo(options.bind_address, NULL, &hints, &res);
Ben Lindstrome0f88042001-04-30 13:06:24 +0000212 if (gaierr) {
213 error("getaddrinfo: %s: %s", options.bind_address,
Darren Tucker4abde772007-12-29 02:43:51 +1100214 ssh_gai_strerror(gaierr));
Ben Lindstrome0f88042001-04-30 13:06:24 +0000215 close(sock);
216 return -1;
217 }
218 if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
219 error("bind: %s: %s", options.bind_address, strerror(errno));
220 close(sock);
221 freeaddrinfo(res);
222 return -1;
223 }
224 freeaddrinfo(res);
Damien Miller95def091999-11-25 00:26:21 +1100225 return sock;
226}
227
Damien Millerb78d5eb2003-05-16 11:39:04 +1000228static int
229timeout_connect(int sockfd, const struct sockaddr *serv_addr,
Damien Miller67bd0622007-09-17 12:06:57 +1000230 socklen_t addrlen, int *timeoutp)
Damien Millerb78d5eb2003-05-16 11:39:04 +1000231{
232 fd_set *fdset;
Damien Miller67bd0622007-09-17 12:06:57 +1000233 struct timeval tv, t_start;
Damien Millerb78d5eb2003-05-16 11:39:04 +1000234 socklen_t optlen;
Damien Miller07d86be2006-03-26 14:19:21 +1100235 int optval, rc, result = -1;
Damien Millerb78d5eb2003-05-16 11:39:04 +1000236
Damien Miller67bd0622007-09-17 12:06:57 +1000237 gettimeofday(&t_start, NULL);
238
239 if (*timeoutp <= 0) {
240 result = connect(sockfd, serv_addr, addrlen);
241 goto done;
242 }
Damien Millerb78d5eb2003-05-16 11:39:04 +1000243
Damien Millerf6723f02004-01-27 21:21:27 +1100244 set_nonblock(sockfd);
Damien Millerb78d5eb2003-05-16 11:39:04 +1000245 rc = connect(sockfd, serv_addr, addrlen);
Damien Millerf6723f02004-01-27 21:21:27 +1100246 if (rc == 0) {
247 unset_nonblock(sockfd);
Damien Miller67bd0622007-09-17 12:06:57 +1000248 result = 0;
249 goto done;
Damien Millerf6723f02004-01-27 21:21:27 +1100250 }
Damien Miller67bd0622007-09-17 12:06:57 +1000251 if (errno != EINPROGRESS) {
252 result = -1;
253 goto done;
254 }
Damien Millerb78d5eb2003-05-16 11:39:04 +1000255
Damien Miller07d86be2006-03-26 14:19:21 +1100256 fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
257 sizeof(fd_mask));
Damien Millerb78d5eb2003-05-16 11:39:04 +1000258 FD_SET(sockfd, fdset);
Damien Miller67bd0622007-09-17 12:06:57 +1000259 ms_to_timeval(&tv, *timeoutp);
Damien Millerb78d5eb2003-05-16 11:39:04 +1000260
Darren Tucker47eede72005-03-14 23:08:12 +1100261 for (;;) {
Damien Millerb78d5eb2003-05-16 11:39:04 +1000262 rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
263 if (rc != -1 || errno != EINTR)
264 break;
265 }
266
Darren Tucker47eede72005-03-14 23:08:12 +1100267 switch (rc) {
Damien Millerb78d5eb2003-05-16 11:39:04 +1000268 case 0:
269 /* Timed out */
270 errno = ETIMEDOUT;
Damien Miller08293fa2003-05-23 18:44:41 +1000271 break;
Damien Millerb78d5eb2003-05-16 11:39:04 +1000272 case -1:
273 /* Select error */
Damien Millera8e06ce2003-11-21 23:48:55 +1100274 debug("select: %s", strerror(errno));
Damien Miller08293fa2003-05-23 18:44:41 +1000275 break;
Damien Millerb78d5eb2003-05-16 11:39:04 +1000276 case 1:
277 /* Completed or failed */
278 optval = 0;
279 optlen = sizeof(optval);
Damien Millera8e06ce2003-11-21 23:48:55 +1100280 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
Darren Tuckerbd5361b2003-09-22 20:59:16 +1000281 &optlen) == -1) {
Damien Millera8e06ce2003-11-21 23:48:55 +1100282 debug("getsockopt: %s", strerror(errno));
Damien Miller08293fa2003-05-23 18:44:41 +1000283 break;
Darren Tuckerbd5361b2003-09-22 20:59:16 +1000284 }
Damien Millerb78d5eb2003-05-16 11:39:04 +1000285 if (optval != 0) {
286 errno = optval;
Damien Miller08293fa2003-05-23 18:44:41 +1000287 break;
Damien Millerb78d5eb2003-05-16 11:39:04 +1000288 }
Damien Miller08293fa2003-05-23 18:44:41 +1000289 result = 0;
Damien Millerf6723f02004-01-27 21:21:27 +1100290 unset_nonblock(sockfd);
Damien Millerb78d5eb2003-05-16 11:39:04 +1000291 break;
292 default:
293 /* Should not occur */
294 fatal("Bogus return (%d) from select()", rc);
295 }
296
Damien Miller08293fa2003-05-23 18:44:41 +1000297 xfree(fdset);
Damien Miller67bd0622007-09-17 12:06:57 +1000298
299 done:
300 if (result == 0 && *timeoutp > 0) {
301 ms_subtract_diff(&t_start, timeoutp);
302 if (*timeoutp <= 0) {
303 errno = ETIMEDOUT;
304 result = -1;
305 }
306 }
307
Damien Miller08293fa2003-05-23 18:44:41 +1000308 return (result);
Damien Millerb78d5eb2003-05-16 11:39:04 +1000309}
310
Damien Miller95def091999-11-25 00:26:21 +1100311/*
Damien Miller34132e52000-01-14 15:45:46 +1100312 * Opens a TCP/IP connection to the remote server on the given host.
313 * The address of the remote host will be returned in hostaddr.
Ben Lindstromf9c48842002-06-11 16:37:51 +0000314 * If port is 0, the default port will be used. If needpriv is true,
Damien Miller95def091999-11-25 00:26:21 +1100315 * a privileged port will be allocated to make the connection.
Ben Lindstromf9c48842002-06-11 16:37:51 +0000316 * This requires super-user privileges if needpriv is true.
Damien Miller95def091999-11-25 00:26:21 +1100317 * Connection_attempts specifies the maximum number of tries (one per
318 * second). If proxy_command is non-NULL, it specifies the command (with %h
319 * and %p substituted for host and port, respectively) to use to contact
320 * the daemon.
321 */
322int
Damien Miller34132e52000-01-14 15:45:46 +1100323ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
Damien Miller67bd0622007-09-17 12:06:57 +1000324 u_short port, int family, int connection_attempts, int *timeout_ms,
325 int want_keepalive, int needpriv, const char *proxy_command)
Damien Miller95def091999-11-25 00:26:21 +1100326{
Damien Miller34132e52000-01-14 15:45:46 +1100327 int gaierr;
Ben Lindstrombf555ba2001-01-18 02:04:35 +0000328 int on = 1;
329 int sock = -1, attempt;
330 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
331 struct addrinfo hints, *ai, *aitop;
Damien Miller95def091999-11-25 00:26:21 +1100332
Ben Lindstrom064496f2002-12-23 02:04:22 +0000333 debug2("ssh_connect: needpriv %d", needpriv);
Damien Miller95def091999-11-25 00:26:21 +1100334
Damien Miller95def091999-11-25 00:26:21 +1100335 /* If a proxy command is given, connect using it. */
336 if (proxy_command != NULL)
Ben Lindstromf9c48842002-06-11 16:37:51 +0000337 return ssh_proxy_connect(host, port, proxy_command);
Damien Miller95def091999-11-25 00:26:21 +1100338
339 /* No proxy command. */
340
Damien Miller34132e52000-01-14 15:45:46 +1100341 memset(&hints, 0, sizeof(hints));
Damien Miller139d4cd2001-10-10 15:07:44 +1000342 hints.ai_family = family;
Damien Miller34132e52000-01-14 15:45:46 +1100343 hints.ai_socktype = SOCK_STREAM;
Ben Lindstrom5c385522002-06-23 21:23:20 +0000344 snprintf(strport, sizeof strport, "%u", port);
Damien Miller34132e52000-01-14 15:45:46 +1100345 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
Darren Tucker4abde772007-12-29 02:43:51 +1100346 fatal("%s: Could not resolve hostname %.100s: %s", __progname,
347 host, ssh_gai_strerror(gaierr));
Damien Miller95def091999-11-25 00:26:21 +1100348
Damien Miller56e5e6a2006-04-23 12:08:59 +1000349 for (attempt = 0; attempt < connection_attempts; attempt++) {
Damien Millerf4bcd102006-10-24 03:02:23 +1000350 if (attempt > 0) {
351 /* Sleep a moment before retrying. */
352 sleep(1);
Damien Miller95def091999-11-25 00:26:21 +1100353 debug("Trying again...");
Damien Millerf4bcd102006-10-24 03:02:23 +1000354 }
Damien Miller56e5e6a2006-04-23 12:08:59 +1000355 /*
356 * Loop through addresses for this host, and try each one in
357 * sequence until the connection succeeds.
358 */
Damien Miller34132e52000-01-14 15:45:46 +1100359 for (ai = aitop; ai; ai = ai->ai_next) {
360 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
361 continue;
362 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
363 ntop, sizeof(ntop), strport, sizeof(strport),
364 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
365 error("ssh_connect: getnameinfo failed");
366 continue;
367 }
368 debug("Connecting to %.200s [%.100s] port %s.",
369 host, ntop, strport);
Damien Miller95def091999-11-25 00:26:21 +1100370
Damien Miller34132e52000-01-14 15:45:46 +1100371 /* Create a socket for connecting. */
Damien Miller2372ace2003-05-14 13:42:23 +1000372 sock = ssh_create_socket(needpriv, ai);
Damien Miller34132e52000-01-14 15:45:46 +1100373 if (sock < 0)
Ben Lindstromf9cedb92001-08-06 21:07:11 +0000374 /* Any error is already output */
Damien Miller34132e52000-01-14 15:45:46 +1100375 continue;
Damien Miller95def091999-11-25 00:26:21 +1100376
Damien Millerb78d5eb2003-05-16 11:39:04 +1000377 if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
Damien Miller67bd0622007-09-17 12:06:57 +1000378 timeout_ms) >= 0) {
Damien Miller34132e52000-01-14 15:45:46 +1100379 /* Successful connection. */
Ben Lindstroma3700052001-04-05 23:26:32 +0000380 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
Damien Miller95def091999-11-25 00:26:21 +1100381 break;
Damien Miller34132e52000-01-14 15:45:46 +1100382 } else {
Ben Lindstrom728aa7e2002-07-15 17:48:11 +0000383 debug("connect to address %s port %s: %s",
384 ntop, strport, strerror(errno));
Damien Miller95def091999-11-25 00:26:21 +1100385 close(sock);
Damien Miller56e5e6a2006-04-23 12:08:59 +1000386 sock = -1;
Damien Miller95def091999-11-25 00:26:21 +1100387 }
Damien Miller95def091999-11-25 00:26:21 +1100388 }
Damien Miller56e5e6a2006-04-23 12:08:59 +1000389 if (sock != -1)
Damien Miller34132e52000-01-14 15:45:46 +1100390 break; /* Successful connection. */
Damien Miller95def091999-11-25 00:26:21 +1100391 }
Damien Miller34132e52000-01-14 15:45:46 +1100392
393 freeaddrinfo(aitop);
394
Damien Miller95def091999-11-25 00:26:21 +1100395 /* Return failure if we didn't get a successful connection. */
Damien Miller56e5e6a2006-04-23 12:08:59 +1000396 if (sock == -1) {
Darren Tuckerb2161e32005-01-20 11:00:46 +1100397 error("ssh: connect to host %s port %s: %s",
Ben Lindstroma6cd75c2002-07-11 04:00:19 +0000398 host, strport, strerror(errno));
Darren Tuckerb2161e32005-01-20 11:00:46 +1100399 return (-1);
Ben Lindstroma6cd75c2002-07-11 04:00:19 +0000400 }
Damien Miller95def091999-11-25 00:26:21 +1100401
402 debug("Connection established.");
403
Damien Miller12c150e2003-12-17 16:31:10 +1100404 /* Set SO_KEEPALIVE if requested. */
Damien Miller67bd0622007-09-17 12:06:57 +1000405 if (want_keepalive &&
Ben Lindstrombf555ba2001-01-18 02:04:35 +0000406 setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
407 sizeof(on)) < 0)
408 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
Damien Miller95def091999-11-25 00:26:21 +1100409
410 /* Set the connection. */
411 packet_set_connection(sock, sock);
Darren Tucker3fc464e2008-06-13 06:42:45 +1000412 packet_set_timeout(options.server_alive_interval,
413 options.server_alive_count_max);
Damien Miller95def091999-11-25 00:26:21 +1100414
Ben Lindstromf9cedb92001-08-06 21:07:11 +0000415 return 0;
Damien Miller95def091999-11-25 00:26:21 +1100416}
417
Damien Milleraae6c611999-12-06 11:47:28 +1100418/*
Damien Miller95def091999-11-25 00:26:21 +1100419 * Waits for the server identification string, and sends our own
420 * identification string.
421 */
Darren Tucker1cc55d72009-06-21 18:17:19 +1000422void
Damien Miller67bd0622007-09-17 12:06:57 +1000423ssh_exchange_identification(int timeout_ms)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000424{
Damien Miller95def091999-11-25 00:26:21 +1100425 char buf[256], remote_version[256]; /* must be same size! */
Damien Millereccb9de2005-06-17 12:59:34 +1000426 int remote_major, remote_minor, mismatch;
Damien Miller95def091999-11-25 00:26:21 +1100427 int connection_in = packet_get_connection_in();
428 int connection_out = packet_get_connection_out();
Kevin Stevesef4eea92001-02-05 12:42:17 +0000429 int minor1 = PROTOCOL_MINOR_1;
Damien Miller1e88ea62006-07-10 20:15:56 +1000430 u_int i, n;
Damien Miller67bd0622007-09-17 12:06:57 +1000431 size_t len;
432 int fdsetsz, remaining, rc;
433 struct timeval t_start, t_remaining;
434 fd_set *fdset;
435
436 fdsetsz = howmany(connection_in + 1, NFDBITS) * sizeof(fd_mask);
437 fdset = xcalloc(1, fdsetsz);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000438
Damien Millerb253cc42005-05-26 12:23:44 +1000439 /* Read other side's version identification. */
Damien Miller67bd0622007-09-17 12:06:57 +1000440 remaining = timeout_ms;
Damien Miller1e88ea62006-07-10 20:15:56 +1000441 for (n = 0;;) {
Damien Millerf6d9e222000-06-18 14:50:44 +1000442 for (i = 0; i < sizeof(buf) - 1; i++) {
Damien Miller67bd0622007-09-17 12:06:57 +1000443 if (timeout_ms > 0) {
444 gettimeofday(&t_start, NULL);
445 ms_to_timeval(&t_remaining, remaining);
446 FD_SET(connection_in, fdset);
447 rc = select(connection_in + 1, fdset, NULL,
448 fdset, &t_remaining);
449 ms_subtract_diff(&t_start, &remaining);
450 if (rc == 0 || remaining <= 0)
451 fatal("Connection timed out during "
452 "banner exchange");
453 if (rc == -1) {
454 if (errno == EINTR)
455 continue;
456 fatal("ssh_exchange_identification: "
457 "select: %s", strerror(errno));
458 }
459 }
460
Darren Tuckerc5564e12009-06-21 18:53:53 +1000461 len = roaming_atomicio(read, connection_in, &buf[i], 1);
Damien Millerb253cc42005-05-26 12:23:44 +1000462
Damien Miller46d38de2005-07-17 17:02:09 +1000463 if (len != 1 && errno == EPIPE)
Damien Miller67bd0622007-09-17 12:06:57 +1000464 fatal("ssh_exchange_identification: "
465 "Connection closed by remote host");
Damien Millerb253cc42005-05-26 12:23:44 +1000466 else if (len != 1)
Damien Miller67bd0622007-09-17 12:06:57 +1000467 fatal("ssh_exchange_identification: "
468 "read: %.100s", strerror(errno));
Damien Millerf6d9e222000-06-18 14:50:44 +1000469 if (buf[i] == '\r') {
470 buf[i] = '\n';
471 buf[i + 1] = 0;
472 continue; /**XXX wait for \n */
473 }
474 if (buf[i] == '\n') {
475 buf[i + 1] = 0;
476 break;
477 }
Damien Miller1e88ea62006-07-10 20:15:56 +1000478 if (++n > 65536)
Damien Miller67bd0622007-09-17 12:06:57 +1000479 fatal("ssh_exchange_identification: "
480 "No banner received");
Damien Miller95def091999-11-25 00:26:21 +1100481 }
Damien Millerf6d9e222000-06-18 14:50:44 +1000482 buf[sizeof(buf) - 1] = 0;
483 if (strncmp(buf, "SSH-", 4) == 0)
Damien Miller95def091999-11-25 00:26:21 +1100484 break;
Damien Millerf6d9e222000-06-18 14:50:44 +1000485 debug("ssh_exchange_identification: %s", buf);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000486 }
Damien Miller1383bd82000-04-06 12:32:37 +1000487 server_version_string = xstrdup(buf);
Damien Miller67bd0622007-09-17 12:06:57 +1000488 xfree(fdset);
Damien Miller95def091999-11-25 00:26:21 +1100489
Damien Miller5428f641999-11-25 11:54:57 +1100490 /*
491 * Check that the versions match. In future this might accept
492 * several versions and set appropriate flags to handle them.
493 */
Damien Miller1383bd82000-04-06 12:32:37 +1000494 if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
495 &remote_major, &remote_minor, remote_version) != 3)
Damien Miller95def091999-11-25 00:26:21 +1100496 fatal("Bad remote protocol version identification: '%.100s'", buf);
497 debug("Remote protocol version %d.%d, remote software version %.100s",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100498 remote_major, remote_minor, remote_version);
Damien Miller95def091999-11-25 00:26:21 +1100499
Damien Miller1383bd82000-04-06 12:32:37 +1000500 compat_datafellows(remote_version);
Damien Miller78928792000-04-12 20:17:38 +1000501 mismatch = 0;
Damien Miller1383bd82000-04-06 12:32:37 +1000502
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000503 switch (remote_major) {
Damien Miller78928792000-04-12 20:17:38 +1000504 case 1:
505 if (remote_minor == 99 &&
506 (options.protocol & SSH_PROTO_2) &&
507 !(options.protocol & SSH_PROTO_1_PREFERRED)) {
508 enable_compat20();
509 break;
Damien Miller95def091999-11-25 00:26:21 +1100510 }
Damien Miller78928792000-04-12 20:17:38 +1000511 if (!(options.protocol & SSH_PROTO_1)) {
512 mismatch = 1;
513 break;
514 }
515 if (remote_minor < 3) {
516 fatal("Remote machine has too old SSH software version.");
Damien Miller0bc1bd82000-11-13 22:57:25 +1100517 } else if (remote_minor == 3 || remote_minor == 4) {
Damien Miller78928792000-04-12 20:17:38 +1000518 /* We speak 1.3, too. */
519 enable_compat13();
Damien Miller0bc1bd82000-11-13 22:57:25 +1100520 minor1 = 3;
Damien Miller78928792000-04-12 20:17:38 +1000521 if (options.forward_agent) {
Damien Miller996acd22003-04-09 20:59:48 +1000522 logit("Agent forwarding disabled for protocol 1.3");
Damien Miller78928792000-04-12 20:17:38 +1000523 options.forward_agent = 0;
524 }
525 }
526 break;
527 case 2:
528 if (options.protocol & SSH_PROTO_2) {
529 enable_compat20();
530 break;
531 }
532 /* FALLTHROUGH */
Damien Miller4af51302000-04-16 11:18:38 +1000533 default:
Damien Miller78928792000-04-12 20:17:38 +1000534 mismatch = 1;
535 break;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000536 }
Damien Miller78928792000-04-12 20:17:38 +1000537 if (mismatch)
Damien Miller95def091999-11-25 00:26:21 +1100538 fatal("Protocol major versions differ: %d vs. %d",
Damien Miller78928792000-04-12 20:17:38 +1000539 (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
540 remote_major);
Damien Miller95def091999-11-25 00:26:21 +1100541 /* Send our own protocol version identification. */
Darren Tuckerd7bdc0c2008-07-02 22:34:30 +1000542 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s%s",
Damien Miller78928792000-04-12 20:17:38 +1000543 compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
Damien Miller0bc1bd82000-11-13 22:57:25 +1100544 compat20 ? PROTOCOL_MINOR_2 : minor1,
Darren Tuckerd7bdc0c2008-07-02 22:34:30 +1000545 SSH_VERSION, compat20 ? "\r\n" : "\n");
Darren Tuckerc5564e12009-06-21 18:53:53 +1000546 if (roaming_atomicio(vwrite, connection_out, buf, strlen(buf))
547 != strlen(buf))
Damien Miller95def091999-11-25 00:26:21 +1100548 fatal("write: %.100s", strerror(errno));
Damien Miller1383bd82000-04-06 12:32:37 +1000549 client_version_string = xstrdup(buf);
550 chop(client_version_string);
551 chop(server_version_string);
552 debug("Local version string %.100s", client_version_string);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000553}
554
Ben Lindstromb6c06d92001-02-10 23:21:09 +0000555/* defaults to 'no' */
Ben Lindstrombba81212001-06-25 05:01:22 +0000556static int
Damien Millere3980042001-10-10 15:02:03 +1000557confirm(const char *prompt)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000558{
Damien Miller49d795c2002-01-22 23:34:12 +1100559 const char *msg, *again = "Please type 'yes' or 'no': ";
560 char *p;
561 int ret = -1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000562
Ben Lindstromb6c06d92001-02-10 23:21:09 +0000563 if (options.batch_mode)
564 return 0;
Damien Miller49d795c2002-01-22 23:34:12 +1100565 for (msg = prompt;;msg = again) {
566 p = read_passphrase(msg, RP_ECHO);
567 if (p == NULL ||
568 (p[0] == '\0') || (p[0] == '\n') ||
569 strncasecmp(p, "no", 2) == 0)
570 ret = 0;
Ben Lindstrom04f9af72002-07-04 00:03:56 +0000571 if (p && strncasecmp(p, "yes", 3) == 0)
Damien Miller49d795c2002-01-22 23:34:12 +1100572 ret = 1;
573 if (p)
574 xfree(p);
575 if (ret != -1)
576 return ret;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000577 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000578}
579
Damien Miller0a80ca12010-02-27 07:55:05 +1100580static int
581check_host_cert(const char *host, const Key *host_key)
582{
583 const char *reason;
584
585 if (key_cert_check_authority(host_key, 1, 0, host, &reason) != 0) {
586 error("%s", reason);
587 return 0;
588 }
589 if (buffer_len(&host_key->cert->constraints) != 0) {
590 error("Certificate for %s contains unsupported constraint(s)",
591 host);
592 return 0;
593 }
594 return 1;
595}
596
Damien Miller95def091999-11-25 00:26:21 +1100597/*
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000598 * check whether the supplied host key is valid, return -1 if the key
599 * is not valid. the user_hostfile will not be updated if 'readonly' is true.
Damien Miller95def091999-11-25 00:26:21 +1100600 */
Damien Millerda828392006-08-05 11:35:45 +1000601#define RDRW 0
602#define RDONLY 1
603#define ROQUIET 2
Ben Lindstrombba81212001-06-25 05:01:22 +0000604static int
Damien Millerda828392006-08-05 11:35:45 +1000605check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port,
606 Key *host_key, int readonly, const char *user_hostfile,
607 const char *system_hostfile)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000608{
Damien Miller0a80ca12010-02-27 07:55:05 +1100609 Key *file_key, *raw_key = NULL;
610 const char *type;
Darren Tuckerda345532006-07-10 23:04:19 +1000611 char *ip = NULL, *host = NULL;
Darren Tucker9c16ac92008-06-13 04:40:35 +1000612 char hostline[1000], *hostp, *fp, *ra;
Damien Miller95def091999-11-25 00:26:21 +1100613 HostStatus host_status;
614 HostStatus ip_status;
Damien Miller0a80ca12010-02-27 07:55:05 +1100615 int r, want_cert, local = 0, host_ip_differ = 0;
Damien Millereaf99942000-01-19 13:45:07 +1100616 int salen;
Damien Miller34132e52000-01-14 15:45:46 +1100617 char ntop[NI_MAXHOST];
Damien Miller49d795c2002-01-22 23:34:12 +1100618 char msg[1024];
Darren Tucker068e01f2008-07-02 22:33:55 +1000619 int len, host_line, ip_line, cancelled_forwarding = 0;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000620 const char *host_file = NULL, *ip_file = NULL;
Damien Miller34132e52000-01-14 15:45:46 +1100621
622 /*
623 * Force accepting of the host key for loopback/localhost. The
624 * problem is that if the home directory is NFS-mounted to multiple
625 * machines, localhost will refer to a different machine in each of
626 * them, and the user will get bogus HOST_CHANGED warnings. This
627 * essentially disables host authentication for localhost; however,
628 * this is probably not a real problem.
629 */
Damien Millereba71ba2000-04-29 23:57:08 +1000630 /** hostaddr == 0! */
Damien Miller34132e52000-01-14 15:45:46 +1100631 switch (hostaddr->sa_family) {
632 case AF_INET:
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000633 local = (ntohl(((struct sockaddr_in *)hostaddr)->
Damien Miller0dc1bef2005-07-17 17:22:45 +1000634 sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
Damien Millereaf99942000-01-19 13:45:07 +1100635 salen = sizeof(struct sockaddr_in);
Damien Miller34132e52000-01-14 15:45:46 +1100636 break;
637 case AF_INET6:
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000638 local = IN6_IS_ADDR_LOOPBACK(
639 &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
Damien Millereaf99942000-01-19 13:45:07 +1100640 salen = sizeof(struct sockaddr_in6);
Damien Miller34132e52000-01-14 15:45:46 +1100641 break;
642 default:
643 local = 0;
Damien Millereaf99942000-01-19 13:45:07 +1100644 salen = sizeof(struct sockaddr_storage);
Damien Miller34132e52000-01-14 15:45:46 +1100645 break;
646 }
Ben Lindstrom3cecc9a2001-10-03 17:39:38 +0000647 if (options.no_host_authentication_for_localhost == 1 && local &&
648 options.host_key_alias == NULL) {
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000649 debug("Forcing accepting of host key for "
650 "loopback/localhost.");
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000651 return 0;
Damien Miller34132e52000-01-14 15:45:46 +1100652 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000653
Damien Milleraae6c611999-12-06 11:47:28 +1100654 /*
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000655 * We don't have the remote ip-address for connections
656 * using a proxy command
Damien Milleraae6c611999-12-06 11:47:28 +1100657 */
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000658 if (options.proxy_command == NULL) {
659 if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop),
660 NULL, 0, NI_NUMERICHOST) != 0)
661 fatal("check_host_key: getnameinfo failed");
Damien Millerda828392006-08-05 11:35:45 +1000662 ip = put_host_port(ntop, port);
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000663 } else {
664 ip = xstrdup("<no hostip for proxy command>");
665 }
Darren Tucker78913e02008-06-13 04:47:34 +1000666
667 /*
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000668 * Turn off check_host_ip if the connection is to localhost, via proxy
669 * command or if we don't have a hostname to compare with
670 */
Darren Tuckerda345532006-07-10 23:04:19 +1000671 if (options.check_host_ip && (local ||
672 strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
Damien Milleraae6c611999-12-06 11:47:28 +1100673 options.check_host_ip = 0;
674
Damien Millera34a28b1999-12-14 10:47:15 +1100675 /*
Darren Tuckerda345532006-07-10 23:04:19 +1000676 * Allow the user to record the key under a different name or
677 * differentiate a non-standard port. This is useful for ssh
678 * tunneling over forwarded connections or if you run multiple
679 * sshd's on different ports on the same machine.
Ben Lindstrom4dccfa52000-12-28 16:40:05 +0000680 */
681 if (options.host_key_alias != NULL) {
Darren Tuckerda345532006-07-10 23:04:19 +1000682 host = xstrdup(options.host_key_alias);
Ben Lindstrom4dccfa52000-12-28 16:40:05 +0000683 debug("using hostkeyalias: %s", host);
Darren Tuckerda345532006-07-10 23:04:19 +1000684 } else {
Damien Millerda828392006-08-05 11:35:45 +1000685 host = put_host_port(hostname, port);
Ben Lindstrom4dccfa52000-12-28 16:40:05 +0000686 }
687
Damien Miller0a80ca12010-02-27 07:55:05 +1100688 retry:
689 want_cert = key_is_cert(host_key);
690 type = key_type(host_key);
691
Ben Lindstrom4dccfa52000-12-28 16:40:05 +0000692 /*
Damien Millera34a28b1999-12-14 10:47:15 +1100693 * Store the host key from the known host file in here so that we can
694 * compare it with the key for the IP address.
695 */
Damien Miller0a80ca12010-02-27 07:55:05 +1100696 file_key = key_new(key_is_cert(host_key) ? KEY_UNSPEC : host_key->type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000697
Damien Miller5428f641999-11-25 11:54:57 +1100698 /*
Damien Miller788f2122005-11-05 15:14:59 +1100699 * Check if the host key is present in the user's list of known
Damien Miller5428f641999-11-25 11:54:57 +1100700 * hosts or in the systemwide list.
701 */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000702 host_file = user_hostfile;
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000703 host_status = check_host_in_hostfile(host_file, host, host_key,
Damien Miller9f0f5c62001-12-21 14:45:46 +1100704 file_key, &host_line);
Ben Lindstrom46c16222000-12-22 01:43:59 +0000705 if (host_status == HOST_NEW) {
706 host_file = system_hostfile;
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000707 host_status = check_host_in_hostfile(host_file, host, host_key,
708 file_key, &host_line);
Ben Lindstrom46c16222000-12-22 01:43:59 +0000709 }
Damien Miller5428f641999-11-25 11:54:57 +1100710 /*
Damien Miller5428f641999-11-25 11:54:57 +1100711 * Also perform check for the ip address, skip the check if we are
Damien Miller0a80ca12010-02-27 07:55:05 +1100712 * localhost, looking for a certificate, or the hostname was an ip
713 * address to begin with.
Damien Miller5428f641999-11-25 11:54:57 +1100714 */
Damien Miller0a80ca12010-02-27 07:55:05 +1100715 if (!want_cert && options.check_host_ip) {
Damien Miller450a7a12000-03-26 13:04:51 +1000716 Key *ip_key = key_new(host_key->type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000717
Ben Lindstrom46c16222000-12-22 01:43:59 +0000718 ip_file = user_hostfile;
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000719 ip_status = check_host_in_hostfile(ip_file, ip, host_key,
720 ip_key, &ip_line);
Ben Lindstrom46c16222000-12-22 01:43:59 +0000721 if (ip_status == HOST_NEW) {
722 ip_file = system_hostfile;
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000723 ip_status = check_host_in_hostfile(ip_file, ip,
724 host_key, ip_key, &ip_line);
Ben Lindstrom46c16222000-12-22 01:43:59 +0000725 }
Damien Miller95def091999-11-25 00:26:21 +1100726 if (host_status == HOST_CHANGED &&
Damien Miller450a7a12000-03-26 13:04:51 +1000727 (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
Damien Miller95def091999-11-25 00:26:21 +1100728 host_ip_differ = 1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000729
Damien Miller450a7a12000-03-26 13:04:51 +1000730 key_free(ip_key);
Damien Miller95def091999-11-25 00:26:21 +1100731 } else
732 ip_status = host_status;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000733
Damien Miller450a7a12000-03-26 13:04:51 +1000734 key_free(file_key);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000735
Damien Miller95def091999-11-25 00:26:21 +1100736 switch (host_status) {
737 case HOST_OK:
738 /* The host is known and the key matches. */
Damien Miller0a80ca12010-02-27 07:55:05 +1100739 debug("Host '%.200s' is known and matches the %s host %s.",
740 host, type, want_cert ? "certificate" : "key");
741 debug("Found %s in %s:%d",
742 want_cert ? "certificate" : "key", host_file, host_line);
743 if (want_cert && !check_host_cert(hostname, host_key))
744 goto fail;
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000745 if (options.check_host_ip && ip_status == HOST_NEW) {
Damien Miller0a80ca12010-02-27 07:55:05 +1100746 if (readonly || want_cert)
Damien Miller996acd22003-04-09 20:59:48 +1000747 logit("%s host key for IP address "
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000748 "'%.128s' not in list of known hosts.",
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000749 type, ip);
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000750 else if (!add_host_to_hostfile(user_hostfile, ip,
Damien Millere1776152005-03-01 21:47:37 +1100751 host_key, options.hash_known_hosts))
Damien Miller996acd22003-04-09 20:59:48 +1000752 logit("Failed to add the %s host key for IP "
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000753 "address '%.128s' to the list of known "
754 "hosts (%.30s).", type, ip, user_hostfile);
755 else
Damien Miller996acd22003-04-09 20:59:48 +1000756 logit("Warning: Permanently added the %s host "
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000757 "key for IP address '%.128s' to the list "
758 "of known hosts.", type, ip);
Damien Miller10288242008-06-30 00:04:03 +1000759 } else if (options.visual_host_key) {
Darren Tucker9c16ac92008-06-13 04:40:35 +1000760 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
761 ra = key_fingerprint(host_key, SSH_FP_MD5,
762 SSH_FP_RANDOMART);
763 logit("Host key fingerprint is %s\n%s\n", fp, ra);
764 xfree(ra);
765 xfree(fp);
Damien Miller95def091999-11-25 00:26:21 +1100766 }
767 break;
768 case HOST_NEW:
Damien Millerda828392006-08-05 11:35:45 +1000769 if (options.host_key_alias == NULL && port != 0 &&
770 port != SSH_DEFAULT_PORT) {
771 debug("checking without port identifier");
Damien Millerece92c82008-11-03 19:25:03 +1100772 if (check_host_key(hostname, hostaddr, 0, host_key,
773 ROQUIET, user_hostfile, system_hostfile) == 0) {
Damien Millerda828392006-08-05 11:35:45 +1000774 debug("found matching key w/out port");
775 break;
776 }
777 }
Damien Miller0a80ca12010-02-27 07:55:05 +1100778 if (readonly || want_cert)
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000779 goto fail;
Damien Miller95def091999-11-25 00:26:21 +1100780 /* The host is new. */
781 if (options.strict_host_key_checking == 1) {
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000782 /*
783 * User has requested strict host key checking. We
784 * will not add the host key automatically. The only
785 * alternative left is to abort.
786 */
787 error("No %s host key is known for %.200s and you "
788 "have requested strict checking.", type, host);
789 goto fail;
Damien Miller95def091999-11-25 00:26:21 +1100790 } else if (options.strict_host_key_checking == 2) {
Damien Miller7392ae62003-06-11 22:05:25 +1000791 char msg1[1024], msg2[1024];
792
793 if (show_other_keys(host, host_key))
794 snprintf(msg1, sizeof(msg1),
Damien Miller0dc1bef2005-07-17 17:22:45 +1000795 "\nbut keys of different type are already"
796 " known for this host.");
Damien Miller7392ae62003-06-11 22:05:25 +1000797 else
798 snprintf(msg1, sizeof(msg1), ".");
Damien Miller95def091999-11-25 00:26:21 +1100799 /* The default */
Ben Lindstromcfccef92001-03-13 04:57:58 +0000800 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
Darren Tucker9c16ac92008-06-13 04:40:35 +1000801 ra = key_fingerprint(host_key, SSH_FP_MD5,
802 SSH_FP_RANDOMART);
Damien Miller7392ae62003-06-11 22:05:25 +1000803 msg2[0] = '\0';
Damien Miller7392ae62003-06-11 22:05:25 +1000804 if (options.verify_host_key_dns) {
Damien Miller150b5572003-11-17 21:19:29 +1100805 if (matching_host_key_dns)
Damien Miller7392ae62003-06-11 22:05:25 +1000806 snprintf(msg2, sizeof(msg2),
807 "Matching host key fingerprint"
808 " found in DNS.\n");
809 else
810 snprintf(msg2, sizeof(msg2),
811 "No matching host key fingerprint"
812 " found in DNS.\n");
813 }
Damien Miller49d795c2002-01-22 23:34:12 +1100814 snprintf(msg, sizeof(msg),
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000815 "The authenticity of host '%.200s (%s)' can't be "
Ben Lindstrom3ed66402002-08-01 01:21:56 +0000816 "established%s\n"
Damien Miller10288242008-06-30 00:04:03 +1000817 "%s key fingerprint is %s.%s%s\n%s"
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000818 "Are you sure you want to continue connecting "
Ben Lindstrom3ed66402002-08-01 01:21:56 +0000819 "(yes/no)? ",
Damien Miller10288242008-06-30 00:04:03 +1000820 host, ip, msg1, type, fp,
821 options.visual_host_key ? "\n" : "",
822 options.visual_host_key ? ra : "",
823 msg2);
Darren Tucker9c16ac92008-06-13 04:40:35 +1000824 xfree(ra);
Ben Lindstromcfccef92001-03-13 04:57:58 +0000825 xfree(fp);
Damien Miller49d795c2002-01-22 23:34:12 +1100826 if (!confirm(msg))
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000827 goto fail;
Damien Miller95def091999-11-25 00:26:21 +1100828 }
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000829 /*
830 * If not in strict mode, add the key automatically to the
831 * local known_hosts file.
832 */
Damien Miller1227d4c2005-03-02 12:06:51 +1100833 if (options.check_host_ip && ip_status == HOST_NEW) {
834 snprintf(hostline, sizeof(hostline), "%s,%s",
835 host, ip);
836 hostp = hostline;
837 if (options.hash_known_hosts) {
838 /* Add hash of host and IP separately */
839 r = add_host_to_hostfile(user_hostfile, host,
840 host_key, options.hash_known_hosts) &&
841 add_host_to_hostfile(user_hostfile, ip,
842 host_key, options.hash_known_hosts);
843 } else {
844 /* Add unhashed "host,ip" */
845 r = add_host_to_hostfile(user_hostfile,
846 hostline, host_key,
847 options.hash_known_hosts);
848 }
849 } else {
850 r = add_host_to_hostfile(user_hostfile, host, host_key,
851 options.hash_known_hosts);
852 hostp = host;
853 }
854
855 if (!r)
Damien Miller996acd22003-04-09 20:59:48 +1000856 logit("Failed to add the host to the list of known "
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000857 "hosts (%.500s).", user_hostfile);
Damien Miller95def091999-11-25 00:26:21 +1100858 else
Damien Miller996acd22003-04-09 20:59:48 +1000859 logit("Warning: Permanently added '%.200s' (%s) to the "
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000860 "list of known hosts.", hostp, type);
Damien Miller95def091999-11-25 00:26:21 +1100861 break;
Damien Miller1aed65e2010-03-04 21:53:35 +1100862 case HOST_REVOKED:
863 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
864 error("@ WARNING: REVOKED HOST KEY DETECTED! @");
865 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
866 error("The %s host key for %s is marked as revoked.", type, host);
867 error("This could mean that a stolen key is being used to");
868 error("impersonate this host.");
869
870 /*
871 * If strict host key checking is in use, the user will have
872 * to edit the key manually and we can only abort.
873 */
874 if (options.strict_host_key_checking) {
875 error("%s host key for %.200s was revoked and you have "
876 "requested strict checking.", type, host);
877 goto fail;
878 }
879 goto continue_unsafe;
880
Damien Miller95def091999-11-25 00:26:21 +1100881 case HOST_CHANGED:
Damien Miller0a80ca12010-02-27 07:55:05 +1100882 if (want_cert) {
883 /*
884 * This is only a debug() since it is valid to have
885 * CAs with wildcard DNS matches that don't match
886 * all hosts that one might visit.
887 */
888 debug("Host certificate authority does not "
889 "match %s in %s:%d", CA_MARKER,
890 host_file, host_line);
891 goto fail;
892 }
Damien Millerda828392006-08-05 11:35:45 +1000893 if (readonly == ROQUIET)
894 goto fail;
Damien Miller95def091999-11-25 00:26:21 +1100895 if (options.check_host_ip && host_ip_differ) {
Darren Tucker3f9fdc72004-06-22 12:56:01 +1000896 char *key_msg;
Damien Miller95def091999-11-25 00:26:21 +1100897 if (ip_status == HOST_NEW)
Darren Tucker3f9fdc72004-06-22 12:56:01 +1000898 key_msg = "is unknown";
Damien Miller95def091999-11-25 00:26:21 +1100899 else if (ip_status == HOST_OK)
Darren Tucker3f9fdc72004-06-22 12:56:01 +1000900 key_msg = "is unchanged";
Damien Miller95def091999-11-25 00:26:21 +1100901 else
Darren Tucker3f9fdc72004-06-22 12:56:01 +1000902 key_msg = "has a different value";
Damien Miller95def091999-11-25 00:26:21 +1100903 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
904 error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
905 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
Damien Millere247cc42000-05-07 12:03:14 +1000906 error("The %s host key for %s has changed,", type, host);
Darren Tuckerff4454d2008-06-13 10:21:51 +1000907 error("and the key for the corresponding IP address %s", ip);
Darren Tucker3f9fdc72004-06-22 12:56:01 +1000908 error("%s. This could either mean that", key_msg);
Damien Miller95def091999-11-25 00:26:21 +1100909 error("DNS SPOOFING is happening or the IP address for the host");
Ben Lindstrom46c16222000-12-22 01:43:59 +0000910 error("and its host key have changed at the same time.");
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000911 if (ip_status != HOST_NEW)
Ben Lindstrom46c16222000-12-22 01:43:59 +0000912 error("Offending key for IP in %s:%d", ip_file, ip_line);
Damien Miller95def091999-11-25 00:26:21 +1100913 }
914 /* The host key has changed. */
Damien Miller5a388972003-11-17 21:10:47 +1100915 warn_changed_key(host_key);
Damien Miller95def091999-11-25 00:26:21 +1100916 error("Add correct host key in %.100s to get rid of this message.",
Ben Lindstrom4dccfa52000-12-28 16:40:05 +0000917 user_hostfile);
Ben Lindstrom46c16222000-12-22 01:43:59 +0000918 error("Offending key in %s:%d", host_file, host_line);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000919
Damien Miller5428f641999-11-25 11:54:57 +1100920 /*
921 * If strict host key checking is in use, the user will have
922 * to edit the key manually and we can only abort.
923 */
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000924 if (options.strict_host_key_checking) {
925 error("%s host key for %.200s has changed and you have "
926 "requested strict checking.", type, host);
927 goto fail;
928 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000929
Damien Miller1aed65e2010-03-04 21:53:35 +1100930 continue_unsafe:
Damien Miller5428f641999-11-25 11:54:57 +1100931 /*
932 * If strict host key checking has not been requested, allow
Damien Miller941ac452003-06-04 20:31:53 +1000933 * the connection but without MITM-able authentication or
Damien Miller437edb92006-08-05 09:11:13 +1000934 * forwarding.
Damien Miller5428f641999-11-25 11:54:57 +1100935 */
Damien Miller95def091999-11-25 00:26:21 +1100936 if (options.password_authentication) {
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000937 error("Password authentication is disabled to avoid "
938 "man-in-the-middle attacks.");
Damien Miller95def091999-11-25 00:26:21 +1100939 options.password_authentication = 0;
Darren Tucker068e01f2008-07-02 22:33:55 +1000940 cancelled_forwarding = 1;
Damien Miller95def091999-11-25 00:26:21 +1100941 }
Damien Miller941ac452003-06-04 20:31:53 +1000942 if (options.kbd_interactive_authentication) {
943 error("Keyboard-interactive authentication is disabled"
944 " to avoid man-in-the-middle attacks.");
945 options.kbd_interactive_authentication = 0;
946 options.challenge_response_authentication = 0;
Darren Tucker068e01f2008-07-02 22:33:55 +1000947 cancelled_forwarding = 1;
Damien Miller941ac452003-06-04 20:31:53 +1000948 }
949 if (options.challenge_response_authentication) {
950 error("Challenge/response authentication is disabled"
951 " to avoid man-in-the-middle attacks.");
952 options.challenge_response_authentication = 0;
Darren Tucker068e01f2008-07-02 22:33:55 +1000953 cancelled_forwarding = 1;
Damien Miller941ac452003-06-04 20:31:53 +1000954 }
Damien Miller95def091999-11-25 00:26:21 +1100955 if (options.forward_agent) {
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000956 error("Agent forwarding is disabled to avoid "
957 "man-in-the-middle attacks.");
Damien Miller95def091999-11-25 00:26:21 +1100958 options.forward_agent = 0;
Darren Tucker068e01f2008-07-02 22:33:55 +1000959 cancelled_forwarding = 1;
Damien Miller95def091999-11-25 00:26:21 +1100960 }
Ben Lindstromc72745a2000-12-02 19:03:54 +0000961 if (options.forward_x11) {
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000962 error("X11 forwarding is disabled to avoid "
963 "man-in-the-middle attacks.");
Ben Lindstromc72745a2000-12-02 19:03:54 +0000964 options.forward_x11 = 0;
Darren Tucker068e01f2008-07-02 22:33:55 +1000965 cancelled_forwarding = 1;
Ben Lindstromc72745a2000-12-02 19:03:54 +0000966 }
Ben Lindstromd6481ea2001-06-25 04:37:41 +0000967 if (options.num_local_forwards > 0 ||
968 options.num_remote_forwards > 0) {
969 error("Port forwarding is disabled to avoid "
970 "man-in-the-middle attacks.");
971 options.num_local_forwards =
Damien Miller9f0f5c62001-12-21 14:45:46 +1100972 options.num_remote_forwards = 0;
Darren Tucker068e01f2008-07-02 22:33:55 +1000973 cancelled_forwarding = 1;
Ben Lindstromc72745a2000-12-02 19:03:54 +0000974 }
Damien Miller437edb92006-08-05 09:11:13 +1000975 if (options.tun_open != SSH_TUNMODE_NO) {
976 error("Tunnel forwarding is disabled to avoid "
977 "man-in-the-middle attacks.");
978 options.tun_open = SSH_TUNMODE_NO;
Darren Tucker068e01f2008-07-02 22:33:55 +1000979 cancelled_forwarding = 1;
Damien Miller437edb92006-08-05 09:11:13 +1000980 }
Darren Tucker068e01f2008-07-02 22:33:55 +1000981 if (options.exit_on_forward_failure && cancelled_forwarding)
982 fatal("Error: forwarding disabled due to host key "
983 "check failure");
984
Damien Miller5428f641999-11-25 11:54:57 +1100985 /*
986 * XXX Should permit the user to change to use the new id.
987 * This could be done by converting the host key to an
988 * identifying sentence, tell that the host identifies itself
Darren Tuckere2b36742010-01-13 22:42:34 +1100989 * by that sentence, and ask the user if he/she wishes to
Damien Miller5428f641999-11-25 11:54:57 +1100990 * accept the authentication.
991 */
Damien Miller95def091999-11-25 00:26:21 +1100992 break;
Ben Lindstrom3ed66402002-08-01 01:21:56 +0000993 case HOST_FOUND:
994 fatal("internal error");
995 break;
Damien Miller95def091999-11-25 00:26:21 +1100996 }
Ben Lindstromc72745a2000-12-02 19:03:54 +0000997
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000998 if (options.check_host_ip && host_status != HOST_CHANGED &&
999 ip_status == HOST_CHANGED) {
Damien Miller49d795c2002-01-22 23:34:12 +11001000 snprintf(msg, sizeof(msg),
1001 "Warning: the %s host key for '%.200s' "
1002 "differs from the key for the IP address '%.128s'"
1003 "\nOffending key for IP in %s:%d",
1004 type, host, ip, ip_file, ip_line);
1005 if (host_status == HOST_OK) {
1006 len = strlen(msg);
1007 snprintf(msg + len, sizeof(msg) - len,
1008 "\nMatching host key in %s:%d",
Ben Lindstromcb72e4f2002-06-21 00:41:51 +00001009 host_file, host_line);
Damien Miller49d795c2002-01-22 23:34:12 +11001010 }
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +00001011 if (options.strict_host_key_checking == 1) {
Damien Millerab2db412003-06-02 19:09:13 +10001012 logit("%s", msg);
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001013 error("Exiting, you have requested strict checking.");
1014 goto fail;
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +00001015 } else if (options.strict_host_key_checking == 2) {
Damien Miller49d795c2002-01-22 23:34:12 +11001016 strlcat(msg, "\nAre you sure you want "
1017 "to continue connecting (yes/no)? ", sizeof(msg));
1018 if (!confirm(msg))
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001019 goto fail;
Damien Miller49d795c2002-01-22 23:34:12 +11001020 } else {
Damien Millerab2db412003-06-02 19:09:13 +10001021 logit("%s", msg);
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +00001022 }
1023 }
1024
Ben Lindstromc72745a2000-12-02 19:03:54 +00001025 xfree(ip);
Darren Tuckerda345532006-07-10 23:04:19 +10001026 xfree(host);
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001027 return 0;
1028
1029fail:
Damien Miller1aed65e2010-03-04 21:53:35 +11001030 if (want_cert && host_status != HOST_REVOKED) {
Damien Miller0a80ca12010-02-27 07:55:05 +11001031 /*
1032 * No matching certificate. Downgrade cert to raw key and
1033 * search normally.
1034 */
1035 debug("No matching CA found. Retry with plain key");
1036 raw_key = key_from_private(host_key);
1037 if (key_drop_cert(raw_key) != 0)
1038 fatal("Couldn't drop certificate");
1039 host_key = raw_key;
1040 goto retry;
1041 }
1042 if (raw_key != NULL)
1043 key_free(raw_key);
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001044 xfree(ip);
Darren Tuckerda345532006-07-10 23:04:19 +10001045 xfree(host);
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001046 return -1;
1047}
1048
Damien Miller37876e92003-05-15 10:19:46 +10001049/* returns 0 if key verifies or -1 if key does NOT verify */
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001050int
1051verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
1052{
1053 struct stat st;
Damien Miller150b5572003-11-17 21:19:29 +11001054 int flags = 0;
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001055
Damien Miller0a80ca12010-02-27 07:55:05 +11001056 /* XXX certs are not yet supported for DNS */
1057 if (!key_is_cert(host_key) && options.verify_host_key_dns &&
Damien Miller150b5572003-11-17 21:19:29 +11001058 verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
1059
1060 if (flags & DNS_VERIFY_FOUND) {
1061
1062 if (options.verify_host_key_dns == 1 &&
1063 flags & DNS_VERIFY_MATCH &&
1064 flags & DNS_VERIFY_SECURE)
1065 return 0;
1066
1067 if (flags & DNS_VERIFY_MATCH) {
1068 matching_host_key_dns = 1;
1069 } else {
1070 warn_changed_key(host_key);
1071 error("Update the SSHFP RR in DNS with the new "
1072 "host key to get rid of this message.");
1073 }
Damien Miller37876e92003-05-15 10:19:46 +10001074 }
1075 }
Damien Miller37876e92003-05-15 10:19:46 +10001076
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001077 /* return ok if the key can be found in an old keyfile */
1078 if (stat(options.system_hostfile2, &st) == 0 ||
1079 stat(options.user_hostfile2, &st) == 0) {
Damien Millerda828392006-08-05 11:35:45 +10001080 if (check_host_key(host, hostaddr, options.port, host_key,
1081 RDONLY, options.user_hostfile2,
1082 options.system_hostfile2) == 0)
Ben Lindstromd6481ea2001-06-25 04:37:41 +00001083 return 0;
1084 }
Damien Millerda828392006-08-05 11:35:45 +10001085 return check_host_key(host, hostaddr, options.port, host_key,
1086 RDRW, options.user_hostfile, options.system_hostfile);
Damien Millera34a28b1999-12-14 10:47:15 +11001087}
Damien Miller037a0dc1999-12-07 15:38:31 +11001088
Damien Miller396691a2000-01-20 22:44:08 +11001089/*
1090 * Starts a dialog with the server, and authenticates the current user on the
1091 * server. This does not need any extra privileges. The basic connection
1092 * to the server must already have been established before this is called.
1093 * If login fails, this function prints an error and never returns.
1094 * This function does not require super-user privileges.
1095 */
1096void
Ben Lindstrom1bad2562002-06-06 19:57:33 +00001097ssh_login(Sensitive *sensitive, const char *orighost,
Damien Miller67bd0622007-09-17 12:06:57 +10001098 struct sockaddr *hostaddr, struct passwd *pw, int timeout_ms)
Damien Miller396691a2000-01-20 22:44:08 +11001099{
1100 char *host, *cp;
Damien Millereba71ba2000-04-29 23:57:08 +10001101 char *server_user, *local_user;
1102
Damien Millereba71ba2000-04-29 23:57:08 +10001103 local_user = xstrdup(pw->pw_name);
1104 server_user = options.user ? options.user : local_user;
Damien Miller396691a2000-01-20 22:44:08 +11001105
1106 /* Convert the user-supplied hostname into all lowercase. */
1107 host = xstrdup(orighost);
1108 for (cp = host; *cp; cp++)
1109 if (isupper(*cp))
Damien Miller1d2b6702006-03-26 14:09:54 +11001110 *cp = (char)tolower(*cp);
Damien Miller396691a2000-01-20 22:44:08 +11001111
1112 /* Exchange protocol version identification strings with the server. */
Damien Miller67bd0622007-09-17 12:06:57 +10001113 ssh_exchange_identification(timeout_ms);
Damien Miller396691a2000-01-20 22:44:08 +11001114
1115 /* Put the connection into non-blocking mode. */
1116 packet_set_nonblocking();
1117
Damien Miller396691a2000-01-20 22:44:08 +11001118 /* key exchange */
Damien Miller396691a2000-01-20 22:44:08 +11001119 /* authenticate user */
Damien Miller1383bd82000-04-06 12:32:37 +10001120 if (compat20) {
1121 ssh_kex2(host, hostaddr);
Ben Lindstrom1bad2562002-06-06 19:57:33 +00001122 ssh_userauth2(local_user, server_user, host, sensitive);
Damien Miller1383bd82000-04-06 12:32:37 +10001123 } else {
Damien Miller1383bd82000-04-06 12:32:37 +10001124 ssh_kex(host, hostaddr);
Ben Lindstrom1bad2562002-06-06 19:57:33 +00001125 ssh_userauth1(local_user, server_user, host, sensitive);
Damien Miller1383bd82000-04-06 12:32:37 +10001126 }
Damien Miller40b59852006-06-13 13:00:25 +10001127 xfree(local_user);
Damien Miller396691a2000-01-20 22:44:08 +11001128}
Damien Miller79438cc2001-02-16 12:34:57 +11001129
1130void
1131ssh_put_password(char *password)
1132{
1133 int size;
1134 char *padded;
1135
Ben Lindstromd20d0f32001-03-10 17:22:20 +00001136 if (datafellows & SSH_BUG_PASSWORDPAD) {
Ben Lindstrom664408d2001-06-09 01:42:01 +00001137 packet_put_cstring(password);
Ben Lindstromd20d0f32001-03-10 17:22:20 +00001138 return;
1139 }
Damien Miller79438cc2001-02-16 12:34:57 +11001140 size = roundup(strlen(password) + 1, 32);
Damien Miller07d86be2006-03-26 14:19:21 +11001141 padded = xcalloc(1, size);
Damien Miller79438cc2001-02-16 12:34:57 +11001142 strlcpy(padded, password, size);
1143 packet_put_string(padded, size);
1144 memset(padded, 0, size);
1145 xfree(padded);
1146}
Ben Lindstrom3ed66402002-08-01 01:21:56 +00001147
1148static int
1149show_key_from_file(const char *file, const char *host, int keytype)
1150{
1151 Key *found;
Darren Tucker9c16ac92008-06-13 04:40:35 +10001152 char *fp, *ra;
Ben Lindstrom3ed66402002-08-01 01:21:56 +00001153 int line, ret;
1154
1155 found = key_new(keytype);
1156 if ((ret = lookup_key_in_hostfile_by_type(file, host,
1157 keytype, found, &line))) {
1158 fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
Darren Tucker9c16ac92008-06-13 04:40:35 +10001159 ra = key_fingerprint(found, SSH_FP_MD5, SSH_FP_RANDOMART);
Damien Miller996acd22003-04-09 20:59:48 +10001160 logit("WARNING: %s key found for host %s\n"
Ben Lindstrom4b99be82002-08-01 01:26:29 +00001161 "in %s:%d\n"
Darren Tucker9c16ac92008-06-13 04:40:35 +10001162 "%s key fingerprint %s.\n%s\n",
Ben Lindstrom3ed66402002-08-01 01:21:56 +00001163 key_type(found), host, file, line,
Darren Tucker9c16ac92008-06-13 04:40:35 +10001164 key_type(found), fp, ra);
1165 xfree(ra);
Ben Lindstrom3ed66402002-08-01 01:21:56 +00001166 xfree(fp);
1167 }
1168 key_free(found);
1169 return (ret);
1170}
1171
1172/* print all known host keys for a given host, but skip keys of given type */
1173static int
1174show_other_keys(const char *host, Key *key)
1175{
1176 int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1};
1177 int i, found = 0;
1178
1179 for (i = 0; type[i] != -1; i++) {
1180 if (type[i] == key->type)
1181 continue;
1182 if (type[i] != KEY_RSA1 &&
1183 show_key_from_file(options.user_hostfile2, host, type[i])) {
1184 found = 1;
1185 continue;
1186 }
1187 if (type[i] != KEY_RSA1 &&
1188 show_key_from_file(options.system_hostfile2, host, type[i])) {
1189 found = 1;
1190 continue;
1191 }
1192 if (show_key_from_file(options.user_hostfile, host, type[i])) {
1193 found = 1;
1194 continue;
1195 }
1196 if (show_key_from_file(options.system_hostfile, host, type[i])) {
1197 found = 1;
1198 continue;
1199 }
1200 debug2("no key of type %d for host %s", type[i], host);
1201 }
1202 return (found);
1203}
Damien Miller5a388972003-11-17 21:10:47 +11001204
1205static void
1206warn_changed_key(Key *host_key)
1207{
1208 char *fp;
Damien Miller8f746ec2003-11-17 21:11:15 +11001209 const char *type = key_type(host_key);
Damien Miller5a388972003-11-17 21:10:47 +11001210
1211 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1212
1213 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1214 error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1215 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1216 error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1217 error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1218 error("It is also possible that the %s host key has just been changed.", type);
1219 error("The fingerprint for the %s key sent by the remote host is\n%s.",
1220 type, fp);
1221 error("Please contact your system administrator.");
1222
1223 xfree(fp);
Damien Miller5a388972003-11-17 21:10:47 +11001224}
Damien Millerd27b9472005-12-13 19:29:02 +11001225
1226/*
1227 * Execute a local command
1228 */
1229int
1230ssh_local_cmd(const char *args)
1231{
1232 char *shell;
1233 pid_t pid;
1234 int status;
1235
1236 if (!options.permit_local_command ||
1237 args == NULL || !*args)
1238 return (1);
1239
1240 if ((shell = getenv("SHELL")) == NULL)
1241 shell = _PATH_BSHELL;
1242
1243 pid = fork();
1244 if (pid == 0) {
1245 debug3("Executing %s -c \"%s\"", shell, args);
1246 execl(shell, shell, "-c", args, (char *)NULL);
1247 error("Couldn't execute %s -c \"%s\": %s",
1248 shell, args, strerror(errno));
1249 _exit(1);
1250 } else if (pid == -1)
1251 fatal("fork failed: %.100s", strerror(errno));
1252 while (waitpid(pid, &status, 0) == -1)
1253 if (errno != EINTR)
1254 fatal("Couldn't wait for child: %s", strerror(errno));
1255
1256 if (!WIFEXITED(status))
1257 return (1);
1258
1259 return (WEXITSTATUS(status));
1260}