1 /* $OpenBSD: sshconnect.c,v 1.189 2006/07/10 12:46:51 dtucker Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * Code to connect to a remote host, and to perform the client side of the
7 * login (authentication) dialog.
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".
18 #include <sys/types.h>
21 #include <sys/socket.h>
23 #include <netinet/in.h>
39 #include "sshconnect.h"
48 char *client_version_string = NULL;
49 char *server_version_string = NULL;
51 static int matching_host_key_dns = 0;
54 extern Options options;
55 extern char *__progname;
56 extern uid_t original_real_uid;
57 extern uid_t original_effective_uid;
58 extern pid_t proxy_command_pid;
60 #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */
61 #define INET6_ADDRSTRLEN 46
64 static int show_other_keys(const char *, Key *);
65 static void warn_changed_key(Key *);
68 * Connect to the given ssh server using a proxy command.
71 ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
73 char *command_string, *tmp;
76 char strport[NI_MAXSERV];
78 /* Convert the port number into a string. */
79 snprintf(strport, sizeof strport, "%hu", port);
82 * Build the final command string in the buffer by making the
83 * appropriate substitutions to the given proxy command.
85 * Use "exec" to avoid "sh -c" processes on some platforms
88 xasprintf(&tmp, "exec %s", proxy_command);
89 command_string = percent_expand(tmp, "h", host,
90 "p", strport, (char *)NULL);
93 /* Create pipes for communicating with the proxy. */
94 if (pipe(pin) < 0 || pipe(pout) < 0)
95 fatal("Could not create pipes to communicate with the proxy: %.100s",
98 debug("Executing proxy command: %.500s", command_string);
100 /* Fork and execute the proxy command. */
101 if ((pid = fork()) == 0) {
104 /* Child. Permanently give up superuser privileges. */
105 permanently_drop_suid(original_real_uid);
107 /* Redirect stdin and stdout. */
110 if (dup2(pin[0], 0) < 0)
111 perror("dup2 stdin");
115 if (dup2(pout[1], 1) < 0)
116 perror("dup2 stdout");
117 /* Cannot be 1 because pin allocated two descriptors. */
120 /* Stderr is left as it is so that error messages get
121 printed on the user's terminal. */
122 argv[0] = _PATH_BSHELL;
124 argv[2] = command_string;
127 /* Execute the proxy command. Note that we gave up any
128 extra privileges above. */
129 execv(argv[0], argv);
135 fatal("fork failed: %.100s", strerror(errno));
137 proxy_command_pid = pid; /* save pid to clean up later */
139 /* Close child side of the descriptors. */
143 /* Free the command name. */
144 xfree(command_string);
146 /* Set the connection file descriptors. */
147 packet_set_connection(pout[0], pin[1]);
149 /* Indicate OK return */
154 * Creates a (possibly privileged) socket for use as the ssh connection.
157 ssh_create_socket(int privileged, struct addrinfo *ai)
160 struct addrinfo hints, *res;
163 * If we are running as root and want to connect to a privileged
164 * port, bind our own socket to a privileged port.
167 int p = IPPORT_RESERVED - 1;
169 sock = rresvport_af(&p, ai->ai_family);
172 error("rresvport: af=%d %.100s", ai->ai_family,
175 debug("Allocated local port %d.", p);
178 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
180 error("socket: %.100s", strerror(errno));
182 /* Bind the socket to an alternative local IP address */
183 if (options.bind_address == NULL)
186 memset(&hints, 0, sizeof(hints));
187 hints.ai_family = ai->ai_family;
188 hints.ai_socktype = ai->ai_socktype;
189 hints.ai_protocol = ai->ai_protocol;
190 hints.ai_flags = AI_PASSIVE;
191 gaierr = getaddrinfo(options.bind_address, "0", &hints, &res);
193 error("getaddrinfo: %s: %s", options.bind_address,
194 gai_strerror(gaierr));
198 if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
199 error("bind: %s: %s", options.bind_address, strerror(errno));
209 timeout_connect(int sockfd, const struct sockaddr *serv_addr,
210 socklen_t addrlen, int timeout)
215 int optval, rc, result = -1;
218 return (connect(sockfd, serv_addr, addrlen));
220 set_nonblock(sockfd);
221 rc = connect(sockfd, serv_addr, addrlen);
223 unset_nonblock(sockfd);
226 if (errno != EINPROGRESS)
229 fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
231 FD_SET(sockfd, fdset);
236 rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
237 if (rc != -1 || errno != EINTR)
248 debug("select: %s", strerror(errno));
251 /* Completed or failed */
253 optlen = sizeof(optval);
254 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
256 debug("getsockopt: %s", strerror(errno));
264 unset_nonblock(sockfd);
267 /* Should not occur */
268 fatal("Bogus return (%d) from select()", rc);
276 * Opens a TCP/IP connection to the remote server on the given host.
277 * The address of the remote host will be returned in hostaddr.
278 * If port is 0, the default port will be used. If needpriv is true,
279 * a privileged port will be allocated to make the connection.
280 * This requires super-user privileges if needpriv is true.
281 * Connection_attempts specifies the maximum number of tries (one per
282 * second). If proxy_command is non-NULL, it specifies the command (with %h
283 * and %p substituted for host and port, respectively) to use to contact
287 ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
288 u_short port, int family, int connection_attempts,
289 int needpriv, const char *proxy_command)
293 int sock = -1, attempt;
294 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
295 struct addrinfo hints, *ai, *aitop;
297 debug2("ssh_connect: needpriv %d", needpriv);
299 /* If a proxy command is given, connect using it. */
300 if (proxy_command != NULL)
301 return ssh_proxy_connect(host, port, proxy_command);
303 /* No proxy command. */
305 memset(&hints, 0, sizeof(hints));
306 hints.ai_family = family;
307 hints.ai_socktype = SOCK_STREAM;
308 snprintf(strport, sizeof strport, "%u", port);
309 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
310 fatal("%s: %.100s: %s", __progname, host,
311 gai_strerror(gaierr));
313 for (attempt = 0; attempt < connection_attempts; attempt++) {
315 debug("Trying again...");
318 * Loop through addresses for this host, and try each one in
319 * sequence until the connection succeeds.
321 for (ai = aitop; ai; ai = ai->ai_next) {
322 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
324 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
325 ntop, sizeof(ntop), strport, sizeof(strport),
326 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
327 error("ssh_connect: getnameinfo failed");
330 debug("Connecting to %.200s [%.100s] port %s.",
331 host, ntop, strport);
333 /* Create a socket for connecting. */
334 sock = ssh_create_socket(needpriv, ai);
336 /* Any error is already output */
339 if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
340 options.connection_timeout) >= 0) {
341 /* Successful connection. */
342 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
345 debug("connect to address %s port %s: %s",
346 ntop, strport, strerror(errno));
352 break; /* Successful connection. */
354 /* Sleep a moment before retrying. */
360 /* Return failure if we didn't get a successful connection. */
362 error("ssh: connect to host %s port %s: %s",
363 host, strport, strerror(errno));
367 debug("Connection established.");
369 /* Set SO_KEEPALIVE if requested. */
370 if (options.tcp_keep_alive &&
371 setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
373 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
375 /* Set the connection. */
376 packet_set_connection(sock, sock);
382 * Waits for the server identification string, and sends our own
383 * identification string.
386 ssh_exchange_identification(void)
388 char buf[256], remote_version[256]; /* must be same size! */
389 int remote_major, remote_minor, mismatch;
390 int connection_in = packet_get_connection_in();
391 int connection_out = packet_get_connection_out();
392 int minor1 = PROTOCOL_MINOR_1;
395 /* Read other side's version identification. */
397 for (i = 0; i < sizeof(buf) - 1; i++) {
398 size_t len = atomicio(read, connection_in, &buf[i], 1);
400 if (len != 1 && errno == EPIPE)
401 fatal("ssh_exchange_identification: Connection closed by remote host");
403 fatal("ssh_exchange_identification: read: %.100s", strerror(errno));
404 if (buf[i] == '\r') {
407 continue; /**XXX wait for \n */
409 if (buf[i] == '\n') {
414 fatal("ssh_exchange_identification: No banner received");
416 buf[sizeof(buf) - 1] = 0;
417 if (strncmp(buf, "SSH-", 4) == 0)
419 debug("ssh_exchange_identification: %s", buf);
421 server_version_string = xstrdup(buf);
424 * Check that the versions match. In future this might accept
425 * several versions and set appropriate flags to handle them.
427 if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
428 &remote_major, &remote_minor, remote_version) != 3)
429 fatal("Bad remote protocol version identification: '%.100s'", buf);
430 debug("Remote protocol version %d.%d, remote software version %.100s",
431 remote_major, remote_minor, remote_version);
433 compat_datafellows(remote_version);
436 switch (remote_major) {
438 if (remote_minor == 99 &&
439 (options.protocol & SSH_PROTO_2) &&
440 !(options.protocol & SSH_PROTO_1_PREFERRED)) {
444 if (!(options.protocol & SSH_PROTO_1)) {
448 if (remote_minor < 3) {
449 fatal("Remote machine has too old SSH software version.");
450 } else if (remote_minor == 3 || remote_minor == 4) {
451 /* We speak 1.3, too. */
454 if (options.forward_agent) {
455 logit("Agent forwarding disabled for protocol 1.3");
456 options.forward_agent = 0;
461 if (options.protocol & SSH_PROTO_2) {
471 fatal("Protocol major versions differ: %d vs. %d",
472 (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
474 /* Send our own protocol version identification. */
475 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
476 compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
477 compat20 ? PROTOCOL_MINOR_2 : minor1,
479 if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf))
480 fatal("write: %.100s", strerror(errno));
481 client_version_string = xstrdup(buf);
482 chop(client_version_string);
483 chop(server_version_string);
484 debug("Local version string %.100s", client_version_string);
487 /* defaults to 'no' */
489 confirm(const char *prompt)
491 const char *msg, *again = "Please type 'yes' or 'no': ";
495 if (options.batch_mode)
497 for (msg = prompt;;msg = again) {
498 p = read_passphrase(msg, RP_ECHO);
500 (p[0] == '\0') || (p[0] == '\n') ||
501 strncasecmp(p, "no", 2) == 0)
503 if (p && strncasecmp(p, "yes", 3) == 0)
513 * check whether the supplied host key is valid, return -1 if the key
514 * is not valid. the user_hostfile will not be updated if 'readonly' is true.
517 check_host_key(char *hostname, struct sockaddr *hostaddr, Key *host_key,
518 int readonly, const char *user_hostfile, const char *system_hostfile)
521 const char *type = key_type(host_key);
522 char *ip = NULL, *host = NULL;
523 char hostline[1000], *hostp, *fp;
524 HostStatus host_status;
525 HostStatus ip_status;
526 int r, local = 0, host_ip_differ = 0;
528 char ntop[NI_MAXHOST];
530 int len, host_line, ip_line;
531 const char *host_file = NULL, *ip_file = NULL;
534 * Force accepting of the host key for loopback/localhost. The
535 * problem is that if the home directory is NFS-mounted to multiple
536 * machines, localhost will refer to a different machine in each of
537 * them, and the user will get bogus HOST_CHANGED warnings. This
538 * essentially disables host authentication for localhost; however,
539 * this is probably not a real problem.
541 /** hostaddr == 0! */
542 switch (hostaddr->sa_family) {
544 local = (ntohl(((struct sockaddr_in *)hostaddr)->
545 sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
546 salen = sizeof(struct sockaddr_in);
549 local = IN6_IS_ADDR_LOOPBACK(
550 &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
551 salen = sizeof(struct sockaddr_in6);
555 salen = sizeof(struct sockaddr_storage);
558 if (options.no_host_authentication_for_localhost == 1 && local &&
559 options.host_key_alias == NULL) {
560 debug("Forcing accepting of host key for "
561 "loopback/localhost.");
566 * We don't have the remote ip-address for connections
567 * using a proxy command
569 if (options.proxy_command == NULL) {
570 if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop),
571 NULL, 0, NI_NUMERICHOST) != 0)
572 fatal("check_host_key: getnameinfo failed");
573 ip = put_host_port(ntop, options.port);
575 ip = xstrdup("<no hostip for proxy command>");
578 * Turn off check_host_ip if the connection is to localhost, via proxy
579 * command or if we don't have a hostname to compare with
581 if (options.check_host_ip && (local ||
582 strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
583 options.check_host_ip = 0;
586 * Allow the user to record the key under a different name or
587 * differentiate a non-standard port. This is useful for ssh
588 * tunneling over forwarded connections or if you run multiple
589 * sshd's on different ports on the same machine.
591 if (options.host_key_alias != NULL) {
592 host = xstrdup(options.host_key_alias);
593 debug("using hostkeyalias: %s", host);
595 host = put_host_port(hostname, options.port);
599 * Store the host key from the known host file in here so that we can
600 * compare it with the key for the IP address.
602 file_key = key_new(host_key->type);
605 * Check if the host key is present in the user's list of known
606 * hosts or in the systemwide list.
608 host_file = user_hostfile;
609 host_status = check_host_in_hostfile(host_file, host, host_key,
610 file_key, &host_line);
611 if (host_status == HOST_NEW) {
612 host_file = system_hostfile;
613 host_status = check_host_in_hostfile(host_file, host, host_key,
614 file_key, &host_line);
617 * Also perform check for the ip address, skip the check if we are
618 * localhost or the hostname was an ip address to begin with
620 if (options.check_host_ip) {
621 Key *ip_key = key_new(host_key->type);
623 ip_file = user_hostfile;
624 ip_status = check_host_in_hostfile(ip_file, ip, host_key,
626 if (ip_status == HOST_NEW) {
627 ip_file = system_hostfile;
628 ip_status = check_host_in_hostfile(ip_file, ip,
629 host_key, ip_key, &ip_line);
631 if (host_status == HOST_CHANGED &&
632 (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
637 ip_status = host_status;
641 switch (host_status) {
643 /* The host is known and the key matches. */
644 debug("Host '%.200s' is known and matches the %s host key.",
646 debug("Found key in %s:%d", host_file, host_line);
647 if (options.check_host_ip && ip_status == HOST_NEW) {
649 logit("%s host key for IP address "
650 "'%.128s' not in list of known hosts.",
652 else if (!add_host_to_hostfile(user_hostfile, ip,
653 host_key, options.hash_known_hosts))
654 logit("Failed to add the %s host key for IP "
655 "address '%.128s' to the list of known "
656 "hosts (%.30s).", type, ip, user_hostfile);
658 logit("Warning: Permanently added the %s host "
659 "key for IP address '%.128s' to the list "
660 "of known hosts.", type, ip);
666 /* The host is new. */
667 if (options.strict_host_key_checking == 1) {
669 * User has requested strict host key checking. We
670 * will not add the host key automatically. The only
671 * alternative left is to abort.
673 error("No %s host key is known for %.200s and you "
674 "have requested strict checking.", type, host);
676 } else if (options.strict_host_key_checking == 2) {
677 char msg1[1024], msg2[1024];
679 if (show_other_keys(host, host_key))
680 snprintf(msg1, sizeof(msg1),
681 "\nbut keys of different type are already"
682 " known for this host.");
684 snprintf(msg1, sizeof(msg1), ".");
686 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
688 if (options.verify_host_key_dns) {
689 if (matching_host_key_dns)
690 snprintf(msg2, sizeof(msg2),
691 "Matching host key fingerprint"
694 snprintf(msg2, sizeof(msg2),
695 "No matching host key fingerprint"
698 snprintf(msg, sizeof(msg),
699 "The authenticity of host '%.200s (%s)' can't be "
701 "%s key fingerprint is %s.\n%s"
702 "Are you sure you want to continue connecting "
704 host, ip, msg1, type, fp, msg2);
710 * If not in strict mode, add the key automatically to the
711 * local known_hosts file.
713 if (options.check_host_ip && ip_status == HOST_NEW) {
714 snprintf(hostline, sizeof(hostline), "%s,%s",
717 if (options.hash_known_hosts) {
718 /* Add hash of host and IP separately */
719 r = add_host_to_hostfile(user_hostfile, host,
720 host_key, options.hash_known_hosts) &&
721 add_host_to_hostfile(user_hostfile, ip,
722 host_key, options.hash_known_hosts);
724 /* Add unhashed "host,ip" */
725 r = add_host_to_hostfile(user_hostfile,
727 options.hash_known_hosts);
730 r = add_host_to_hostfile(user_hostfile, host, host_key,
731 options.hash_known_hosts);
736 logit("Failed to add the host to the list of known "
737 "hosts (%.500s).", user_hostfile);
739 logit("Warning: Permanently added '%.200s' (%s) to the "
740 "list of known hosts.", hostp, type);
743 if (options.check_host_ip && host_ip_differ) {
745 if (ip_status == HOST_NEW)
746 key_msg = "is unknown";
747 else if (ip_status == HOST_OK)
748 key_msg = "is unchanged";
750 key_msg = "has a different value";
751 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
752 error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
753 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
754 error("The %s host key for %s has changed,", type, host);
755 error("and the key for the according IP address %s", ip);
756 error("%s. This could either mean that", key_msg);
757 error("DNS SPOOFING is happening or the IP address for the host");
758 error("and its host key have changed at the same time.");
759 if (ip_status != HOST_NEW)
760 error("Offending key for IP in %s:%d", ip_file, ip_line);
762 /* The host key has changed. */
763 warn_changed_key(host_key);
764 error("Add correct host key in %.100s to get rid of this message.",
766 error("Offending key in %s:%d", host_file, host_line);
769 * If strict host key checking is in use, the user will have
770 * to edit the key manually and we can only abort.
772 if (options.strict_host_key_checking) {
773 error("%s host key for %.200s has changed and you have "
774 "requested strict checking.", type, host);
779 * If strict host key checking has not been requested, allow
780 * the connection but without MITM-able authentication or
783 if (options.password_authentication) {
784 error("Password authentication is disabled to avoid "
785 "man-in-the-middle attacks.");
786 options.password_authentication = 0;
788 if (options.kbd_interactive_authentication) {
789 error("Keyboard-interactive authentication is disabled"
790 " to avoid man-in-the-middle attacks.");
791 options.kbd_interactive_authentication = 0;
792 options.challenge_response_authentication = 0;
794 if (options.challenge_response_authentication) {
795 error("Challenge/response authentication is disabled"
796 " to avoid man-in-the-middle attacks.");
797 options.challenge_response_authentication = 0;
799 if (options.forward_agent) {
800 error("Agent forwarding is disabled to avoid "
801 "man-in-the-middle attacks.");
802 options.forward_agent = 0;
804 if (options.forward_x11) {
805 error("X11 forwarding is disabled to avoid "
806 "man-in-the-middle attacks.");
807 options.forward_x11 = 0;
809 if (options.num_local_forwards > 0 ||
810 options.num_remote_forwards > 0) {
811 error("Port forwarding is disabled to avoid "
812 "man-in-the-middle attacks.");
813 options.num_local_forwards =
814 options.num_remote_forwards = 0;
817 * XXX Should permit the user to change to use the new id.
818 * This could be done by converting the host key to an
819 * identifying sentence, tell that the host identifies itself
820 * by that sentence, and ask the user if he/she whishes to
821 * accept the authentication.
825 fatal("internal error");
829 if (options.check_host_ip && host_status != HOST_CHANGED &&
830 ip_status == HOST_CHANGED) {
831 snprintf(msg, sizeof(msg),
832 "Warning: the %s host key for '%.200s' "
833 "differs from the key for the IP address '%.128s'"
834 "\nOffending key for IP in %s:%d",
835 type, host, ip, ip_file, ip_line);
836 if (host_status == HOST_OK) {
838 snprintf(msg + len, sizeof(msg) - len,
839 "\nMatching host key in %s:%d",
840 host_file, host_line);
842 if (options.strict_host_key_checking == 1) {
844 error("Exiting, you have requested strict checking.");
846 } else if (options.strict_host_key_checking == 2) {
847 strlcat(msg, "\nAre you sure you want "
848 "to continue connecting (yes/no)? ", sizeof(msg));
866 /* returns 0 if key verifies or -1 if key does NOT verify */
868 verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
873 if (options.verify_host_key_dns &&
874 verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
876 if (flags & DNS_VERIFY_FOUND) {
878 if (options.verify_host_key_dns == 1 &&
879 flags & DNS_VERIFY_MATCH &&
880 flags & DNS_VERIFY_SECURE)
883 if (flags & DNS_VERIFY_MATCH) {
884 matching_host_key_dns = 1;
886 warn_changed_key(host_key);
887 error("Update the SSHFP RR in DNS with the new "
888 "host key to get rid of this message.");
893 /* return ok if the key can be found in an old keyfile */
894 if (stat(options.system_hostfile2, &st) == 0 ||
895 stat(options.user_hostfile2, &st) == 0) {
896 if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1,
897 options.user_hostfile2, options.system_hostfile2) == 0)
900 return check_host_key(host, hostaddr, host_key, /*readonly*/ 0,
901 options.user_hostfile, options.system_hostfile);
905 * Starts a dialog with the server, and authenticates the current user on the
906 * server. This does not need any extra privileges. The basic connection
907 * to the server must already have been established before this is called.
908 * If login fails, this function prints an error and never returns.
909 * This function does not require super-user privileges.
912 ssh_login(Sensitive *sensitive, const char *orighost,
913 struct sockaddr *hostaddr, struct passwd *pw)
916 char *server_user, *local_user;
918 local_user = xstrdup(pw->pw_name);
919 server_user = options.user ? options.user : local_user;
921 /* Convert the user-supplied hostname into all lowercase. */
922 host = xstrdup(orighost);
923 for (cp = host; *cp; cp++)
925 *cp = (char)tolower(*cp);
927 /* Exchange protocol version identification strings with the server. */
928 ssh_exchange_identification();
930 /* Put the connection into non-blocking mode. */
931 packet_set_nonblocking();
934 /* authenticate user */
936 ssh_kex2(host, hostaddr);
937 ssh_userauth2(local_user, server_user, host, sensitive);
939 ssh_kex(host, hostaddr);
940 ssh_userauth1(local_user, server_user, host, sensitive);
946 ssh_put_password(char *password)
951 if (datafellows & SSH_BUG_PASSWORDPAD) {
952 packet_put_cstring(password);
955 size = roundup(strlen(password) + 1, 32);
956 padded = xcalloc(1, size);
957 strlcpy(padded, password, size);
958 packet_put_string(padded, size);
959 memset(padded, 0, size);
964 show_key_from_file(const char *file, const char *host, int keytype)
970 found = key_new(keytype);
971 if ((ret = lookup_key_in_hostfile_by_type(file, host,
972 keytype, found, &line))) {
973 fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
974 logit("WARNING: %s key found for host %s\n"
976 "%s key fingerprint %s.",
977 key_type(found), host, file, line,
978 key_type(found), fp);
985 /* print all known host keys for a given host, but skip keys of given type */
987 show_other_keys(const char *host, Key *key)
989 int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1};
992 for (i = 0; type[i] != -1; i++) {
993 if (type[i] == key->type)
995 if (type[i] != KEY_RSA1 &&
996 show_key_from_file(options.user_hostfile2, host, type[i])) {
1000 if (type[i] != KEY_RSA1 &&
1001 show_key_from_file(options.system_hostfile2, host, type[i])) {
1005 if (show_key_from_file(options.user_hostfile, host, type[i])) {
1009 if (show_key_from_file(options.system_hostfile, host, type[i])) {
1013 debug2("no key of type %d for host %s", type[i], host);
1019 warn_changed_key(Key *host_key)
1022 const char *type = key_type(host_key);
1024 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1026 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1027 error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1028 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1029 error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1030 error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1031 error("It is also possible that the %s host key has just been changed.", type);
1032 error("The fingerprint for the %s key sent by the remote host is\n%s.",
1034 error("Please contact your system administrator.");
1040 * Execute a local command
1043 ssh_local_cmd(const char *args)
1049 if (!options.permit_local_command ||
1050 args == NULL || !*args)
1053 if ((shell = getenv("SHELL")) == NULL)
1054 shell = _PATH_BSHELL;
1058 debug3("Executing %s -c \"%s\"", shell, args);
1059 execl(shell, shell, "-c", args, (char *)NULL);
1060 error("Couldn't execute %s -c \"%s\": %s",
1061 shell, args, strerror(errno));
1063 } else if (pid == -1)
1064 fatal("fork failed: %.100s", strerror(errno));
1065 while (waitpid(pid, &status, 0) == -1)
1067 fatal("Couldn't wait for child: %s", strerror(errno));
1069 if (!WIFEXITED(status))
1072 return (WEXITSTATUS(status));