2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * Code to connect to a remote host, and to perform the client side of the
6 * login (authentication) dialog.
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
16 RCSID("$OpenBSD: sshconnect.c,v 1.165 2005/06/17 02:44:33 djm Exp $");
18 #include <openssl/bn.h>
28 #include "sshconnect.h"
37 char *client_version_string = NULL;
38 char *server_version_string = NULL;
40 int matching_host_key_dns = 0;
43 extern Options options;
44 extern char *__progname;
45 extern uid_t original_real_uid;
46 extern uid_t original_effective_uid;
47 extern pid_t proxy_command_pid;
49 #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */
50 #define INET6_ADDRSTRLEN 46
53 static int show_other_keys(const char *, Key *);
54 static void warn_changed_key(Key *);
57 * Connect to the given ssh server using a proxy command.
60 ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
62 char *command_string, *tmp;
65 char strport[NI_MAXSERV];
68 /* Convert the port number into a string. */
69 snprintf(strport, sizeof strport, "%hu", port);
72 * Build the final command string in the buffer by making the
73 * appropriate substitutions to the given proxy command.
75 * Use "exec" to avoid "sh -c" processes on some platforms
78 len = strlen(proxy_command) + 6;
80 strlcpy(tmp, "exec ", len);
81 strlcat(tmp, proxy_command, len);
82 command_string = percent_expand(tmp, "h", host,
83 "p", strport, (char *)NULL);
86 /* Create pipes for communicating with the proxy. */
87 if (pipe(pin) < 0 || pipe(pout) < 0)
88 fatal("Could not create pipes to communicate with the proxy: %.100s",
91 debug("Executing proxy command: %.500s", command_string);
93 /* Fork and execute the proxy command. */
94 if ((pid = fork()) == 0) {
97 /* Child. Permanently give up superuser privileges. */
98 seteuid(original_real_uid);
99 setuid(original_real_uid);
101 /* Redirect stdin and stdout. */
104 if (dup2(pin[0], 0) < 0)
105 perror("dup2 stdin");
109 if (dup2(pout[1], 1) < 0)
110 perror("dup2 stdout");
111 /* Cannot be 1 because pin allocated two descriptors. */
114 /* Stderr is left as it is so that error messages get
115 printed on the user's terminal. */
116 argv[0] = _PATH_BSHELL;
118 argv[2] = command_string;
121 /* Execute the proxy command. Note that we gave up any
122 extra privileges above. */
123 execv(argv[0], argv);
129 fatal("fork failed: %.100s", strerror(errno));
131 proxy_command_pid = pid; /* save pid to clean up later */
133 /* Close child side of the descriptors. */
137 /* Free the command name. */
138 xfree(command_string);
140 /* Set the connection file descriptors. */
141 packet_set_connection(pout[0], pin[1]);
143 /* Indicate OK return */
148 * Creates a (possibly privileged) socket for use as the ssh connection.
151 ssh_create_socket(int privileged, struct addrinfo *ai)
154 struct addrinfo hints, *res;
157 * If we are running as root and want to connect to a privileged
158 * port, bind our own socket to a privileged port.
161 int p = IPPORT_RESERVED - 1;
163 sock = rresvport_af(&p, ai->ai_family);
166 error("rresvport: af=%d %.100s", ai->ai_family,
169 debug("Allocated local port %d.", p);
172 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
174 error("socket: %.100s", strerror(errno));
176 /* Bind the socket to an alternative local IP address */
177 if (options.bind_address == NULL)
180 memset(&hints, 0, sizeof(hints));
181 hints.ai_family = ai->ai_family;
182 hints.ai_socktype = ai->ai_socktype;
183 hints.ai_protocol = ai->ai_protocol;
184 hints.ai_flags = AI_PASSIVE;
185 gaierr = getaddrinfo(options.bind_address, "0", &hints, &res);
187 error("getaddrinfo: %s: %s", options.bind_address,
188 gai_strerror(gaierr));
192 if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
193 error("bind: %s: %s", options.bind_address, strerror(errno));
203 timeout_connect(int sockfd, const struct sockaddr *serv_addr,
204 socklen_t addrlen, int timeout)
209 int fdsetsz, optval, rc, result = -1;
212 return (connect(sockfd, serv_addr, addrlen));
214 set_nonblock(sockfd);
215 rc = connect(sockfd, serv_addr, addrlen);
217 unset_nonblock(sockfd);
220 if (errno != EINPROGRESS)
223 fdsetsz = howmany(sockfd + 1, NFDBITS) * sizeof(fd_mask);
224 fdset = (fd_set *)xmalloc(fdsetsz);
226 memset(fdset, 0, fdsetsz);
227 FD_SET(sockfd, fdset);
232 rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
233 if (rc != -1 || errno != EINTR)
244 debug("select: %s", strerror(errno));
247 /* Completed or failed */
249 optlen = sizeof(optval);
250 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
252 debug("getsockopt: %s", strerror(errno));
260 unset_nonblock(sockfd);
263 /* Should not occur */
264 fatal("Bogus return (%d) from select()", rc);
272 * Opens a TCP/IP connection to the remote server on the given host.
273 * The address of the remote host will be returned in hostaddr.
274 * If port is 0, the default port will be used. If needpriv is true,
275 * a privileged port will be allocated to make the connection.
276 * This requires super-user privileges if needpriv is true.
277 * Connection_attempts specifies the maximum number of tries (one per
278 * second). If proxy_command is non-NULL, it specifies the command (with %h
279 * and %p substituted for host and port, respectively) to use to contact
283 ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
284 u_short port, int family, int connection_attempts,
285 int needpriv, const char *proxy_command)
289 int sock = -1, attempt;
290 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
291 struct addrinfo hints, *ai, *aitop;
294 debug2("ssh_connect: needpriv %d", needpriv);
296 /* Get default port if port has not been set. */
298 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
300 port = ntohs(sp->s_port);
302 port = SSH_DEFAULT_PORT;
304 /* If a proxy command is given, connect using it. */
305 if (proxy_command != NULL)
306 return ssh_proxy_connect(host, port, proxy_command);
308 /* No proxy command. */
310 memset(&hints, 0, sizeof(hints));
311 hints.ai_family = family;
312 hints.ai_socktype = SOCK_STREAM;
313 snprintf(strport, sizeof strport, "%u", port);
314 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
315 fatal("%s: %.100s: %s", __progname, host,
316 gai_strerror(gaierr));
319 * Try to connect several times. On some machines, the first time
320 * will sometimes fail. In general socket code appears to behave
321 * quite magically on many machines.
323 for (attempt = 0; ;) {
325 debug("Trying again...");
327 /* Loop through addresses for this host, and try each one in
328 sequence until the connection succeeds. */
329 for (ai = aitop; ai; ai = ai->ai_next) {
330 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
332 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
333 ntop, sizeof(ntop), strport, sizeof(strport),
334 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
335 error("ssh_connect: getnameinfo failed");
338 debug("Connecting to %.200s [%.100s] port %s.",
339 host, ntop, strport);
341 /* Create a socket for connecting. */
342 sock = ssh_create_socket(needpriv, ai);
344 /* Any error is already output */
347 if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
348 options.connection_timeout) >= 0) {
349 /* Successful connection. */
350 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
353 debug("connect to address %s port %s: %s",
354 ntop, strport, strerror(errno));
356 * Close the failed socket; there appear to
357 * be some problems when reusing a socket for
358 * which connect() has already returned an
365 break; /* Successful connection. */
368 if (attempt >= connection_attempts)
370 /* Sleep a moment before retrying. */
376 /* Return failure if we didn't get a successful connection. */
377 if (attempt >= connection_attempts) {
378 error("ssh: connect to host %s port %s: %s",
379 host, strport, strerror(errno));
383 debug("Connection established.");
385 /* Set SO_KEEPALIVE if requested. */
386 if (options.tcp_keep_alive &&
387 setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
389 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
391 /* Set the connection. */
392 packet_set_connection(sock, sock);
398 * Waits for the server identification string, and sends our own
399 * identification string.
402 ssh_exchange_identification(void)
404 char buf[256], remote_version[256]; /* must be same size! */
405 int remote_major, remote_minor, mismatch;
406 int connection_in = packet_get_connection_in();
407 int connection_out = packet_get_connection_out();
408 int minor1 = PROTOCOL_MINOR_1;
411 /* Read other side's version identification. */
413 for (i = 0; i < sizeof(buf) - 1; i++) {
414 size_t len = atomicio(read, connection_in, &buf[i], 1);
416 if (len != 1 && errno == EPIPE)
417 fatal("ssh_exchange_identification: Connection closed by remote host");
419 fatal("ssh_exchange_identification: read: %.100s", strerror(errno));
420 if (buf[i] == '\r') {
423 continue; /**XXX wait for \n */
425 if (buf[i] == '\n') {
430 buf[sizeof(buf) - 1] = 0;
431 if (strncmp(buf, "SSH-", 4) == 0)
433 debug("ssh_exchange_identification: %s", buf);
435 server_version_string = xstrdup(buf);
438 * Check that the versions match. In future this might accept
439 * several versions and set appropriate flags to handle them.
441 if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
442 &remote_major, &remote_minor, remote_version) != 3)
443 fatal("Bad remote protocol version identification: '%.100s'", buf);
444 debug("Remote protocol version %d.%d, remote software version %.100s",
445 remote_major, remote_minor, remote_version);
447 compat_datafellows(remote_version);
450 switch (remote_major) {
452 if (remote_minor == 99 &&
453 (options.protocol & SSH_PROTO_2) &&
454 !(options.protocol & SSH_PROTO_1_PREFERRED)) {
458 if (!(options.protocol & SSH_PROTO_1)) {
462 if (remote_minor < 3) {
463 fatal("Remote machine has too old SSH software version.");
464 } else if (remote_minor == 3 || remote_minor == 4) {
465 /* We speak 1.3, too. */
468 if (options.forward_agent) {
469 logit("Agent forwarding disabled for protocol 1.3");
470 options.forward_agent = 0;
475 if (options.protocol & SSH_PROTO_2) {
485 fatal("Protocol major versions differ: %d vs. %d",
486 (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
488 /* Send our own protocol version identification. */
489 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
490 compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
491 compat20 ? PROTOCOL_MINOR_2 : minor1,
493 if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf))
494 fatal("write: %.100s", strerror(errno));
495 client_version_string = xstrdup(buf);
496 chop(client_version_string);
497 chop(server_version_string);
498 debug("Local version string %.100s", client_version_string);
501 /* defaults to 'no' */
503 confirm(const char *prompt)
505 const char *msg, *again = "Please type 'yes' or 'no': ";
509 if (options.batch_mode)
511 for (msg = prompt;;msg = again) {
512 p = read_passphrase(msg, RP_ECHO);
514 (p[0] == '\0') || (p[0] == '\n') ||
515 strncasecmp(p, "no", 2) == 0)
517 if (p && strncasecmp(p, "yes", 3) == 0)
527 * check whether the supplied host key is valid, return -1 if the key
528 * is not valid. the user_hostfile will not be updated if 'readonly' is true.
531 check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key,
532 int readonly, const char *user_hostfile, const char *system_hostfile)
535 const char *type = key_type(host_key);
537 char hostline[1000], *hostp, *fp;
538 HostStatus host_status;
539 HostStatus ip_status;
540 int r, local = 0, host_ip_differ = 0;
542 char ntop[NI_MAXHOST];
544 int len, host_line, ip_line;
545 const char *host_file = NULL, *ip_file = NULL;
548 * Force accepting of the host key for loopback/localhost. The
549 * problem is that if the home directory is NFS-mounted to multiple
550 * machines, localhost will refer to a different machine in each of
551 * them, and the user will get bogus HOST_CHANGED warnings. This
552 * essentially disables host authentication for localhost; however,
553 * this is probably not a real problem.
555 /** hostaddr == 0! */
556 switch (hostaddr->sa_family) {
558 local = (ntohl(((struct sockaddr_in *)hostaddr)->
559 sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
560 salen = sizeof(struct sockaddr_in);
563 local = IN6_IS_ADDR_LOOPBACK(
564 &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
565 salen = sizeof(struct sockaddr_in6);
569 salen = sizeof(struct sockaddr_storage);
572 if (options.no_host_authentication_for_localhost == 1 && local &&
573 options.host_key_alias == NULL) {
574 debug("Forcing accepting of host key for "
575 "loopback/localhost.");
580 * We don't have the remote ip-address for connections
581 * using a proxy command
583 if (options.proxy_command == NULL) {
584 if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop),
585 NULL, 0, NI_NUMERICHOST) != 0)
586 fatal("check_host_key: getnameinfo failed");
589 ip = xstrdup("<no hostip for proxy command>");
592 * Turn off check_host_ip if the connection is to localhost, via proxy
593 * command or if we don't have a hostname to compare with
595 if (options.check_host_ip &&
596 (local || strcmp(host, ip) == 0 || options.proxy_command != NULL))
597 options.check_host_ip = 0;
600 * Allow the user to record the key under a different name. This is
601 * useful for ssh tunneling over forwarded connections or if you run
602 * multiple sshd's on different ports on the same machine.
604 if (options.host_key_alias != NULL) {
605 host = options.host_key_alias;
606 debug("using hostkeyalias: %s", host);
610 * Store the host key from the known host file in here so that we can
611 * compare it with the key for the IP address.
613 file_key = key_new(host_key->type);
616 * Check if the host key is present in the user\'s list of known
617 * hosts or in the systemwide list.
619 host_file = user_hostfile;
620 host_status = check_host_in_hostfile(host_file, host, host_key,
621 file_key, &host_line);
622 if (host_status == HOST_NEW) {
623 host_file = system_hostfile;
624 host_status = check_host_in_hostfile(host_file, host, host_key,
625 file_key, &host_line);
628 * Also perform check for the ip address, skip the check if we are
629 * localhost or the hostname was an ip address to begin with
631 if (options.check_host_ip) {
632 Key *ip_key = key_new(host_key->type);
634 ip_file = user_hostfile;
635 ip_status = check_host_in_hostfile(ip_file, ip, host_key,
637 if (ip_status == HOST_NEW) {
638 ip_file = system_hostfile;
639 ip_status = check_host_in_hostfile(ip_file, ip,
640 host_key, ip_key, &ip_line);
642 if (host_status == HOST_CHANGED &&
643 (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
648 ip_status = host_status;
652 switch (host_status) {
654 /* The host is known and the key matches. */
655 debug("Host '%.200s' is known and matches the %s host key.",
657 debug("Found key in %s:%d", host_file, host_line);
658 if (options.check_host_ip && ip_status == HOST_NEW) {
660 logit("%s host key for IP address "
661 "'%.128s' not in list of known hosts.",
663 else if (!add_host_to_hostfile(user_hostfile, ip,
664 host_key, options.hash_known_hosts))
665 logit("Failed to add the %s host key for IP "
666 "address '%.128s' to the list of known "
667 "hosts (%.30s).", type, ip, user_hostfile);
669 logit("Warning: Permanently added the %s host "
670 "key for IP address '%.128s' to the list "
671 "of known hosts.", type, ip);
677 /* The host is new. */
678 if (options.strict_host_key_checking == 1) {
680 * User has requested strict host key checking. We
681 * will not add the host key automatically. The only
682 * alternative left is to abort.
684 error("No %s host key is known for %.200s and you "
685 "have requested strict checking.", type, host);
687 } else if (options.strict_host_key_checking == 2) {
688 char msg1[1024], msg2[1024];
690 if (show_other_keys(host, host_key))
691 snprintf(msg1, sizeof(msg1),
692 "\nbut keys of different type are already"
693 " known for this host.");
695 snprintf(msg1, sizeof(msg1), ".");
697 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
699 if (options.verify_host_key_dns) {
700 if (matching_host_key_dns)
701 snprintf(msg2, sizeof(msg2),
702 "Matching host key fingerprint"
705 snprintf(msg2, sizeof(msg2),
706 "No matching host key fingerprint"
709 snprintf(msg, sizeof(msg),
710 "The authenticity of host '%.200s (%s)' can't be "
712 "%s key fingerprint is %s.\n%s"
713 "Are you sure you want to continue connecting "
715 host, ip, msg1, type, fp, msg2);
721 * If not in strict mode, add the key automatically to the
722 * local known_hosts file.
724 if (options.check_host_ip && ip_status == HOST_NEW) {
725 snprintf(hostline, sizeof(hostline), "%s,%s",
728 if (options.hash_known_hosts) {
729 /* Add hash of host and IP separately */
730 r = add_host_to_hostfile(user_hostfile, host,
731 host_key, options.hash_known_hosts) &&
732 add_host_to_hostfile(user_hostfile, ip,
733 host_key, options.hash_known_hosts);
735 /* Add unhashed "host,ip" */
736 r = add_host_to_hostfile(user_hostfile,
738 options.hash_known_hosts);
741 r = add_host_to_hostfile(user_hostfile, host, host_key,
742 options.hash_known_hosts);
747 logit("Failed to add the host to the list of known "
748 "hosts (%.500s).", user_hostfile);
750 logit("Warning: Permanently added '%.200s' (%s) to the "
751 "list of known hosts.", hostp, type);
754 if (options.check_host_ip && host_ip_differ) {
756 if (ip_status == HOST_NEW)
757 key_msg = "is unknown";
758 else if (ip_status == HOST_OK)
759 key_msg = "is unchanged";
761 key_msg = "has a different value";
762 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
763 error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
764 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
765 error("The %s host key for %s has changed,", type, host);
766 error("and the key for the according IP address %s", ip);
767 error("%s. This could either mean that", key_msg);
768 error("DNS SPOOFING is happening or the IP address for the host");
769 error("and its host key have changed at the same time.");
770 if (ip_status != HOST_NEW)
771 error("Offending key for IP in %s:%d", ip_file, ip_line);
773 /* The host key has changed. */
774 warn_changed_key(host_key);
775 error("Add correct host key in %.100s to get rid of this message.",
777 error("Offending key in %s:%d", host_file, host_line);
780 * If strict host key checking is in use, the user will have
781 * to edit the key manually and we can only abort.
783 if (options.strict_host_key_checking) {
784 error("%s host key for %.200s has changed and you have "
785 "requested strict checking.", type, host);
790 * If strict host key checking has not been requested, allow
791 * the connection but without MITM-able authentication or
794 if (options.password_authentication) {
795 error("Password authentication is disabled to avoid "
796 "man-in-the-middle attacks.");
797 options.password_authentication = 0;
799 if (options.kbd_interactive_authentication) {
800 error("Keyboard-interactive authentication is disabled"
801 " to avoid man-in-the-middle attacks.");
802 options.kbd_interactive_authentication = 0;
803 options.challenge_response_authentication = 0;
805 if (options.challenge_response_authentication) {
806 error("Challenge/response authentication is disabled"
807 " to avoid man-in-the-middle attacks.");
808 options.challenge_response_authentication = 0;
810 if (options.forward_agent) {
811 error("Agent forwarding is disabled to avoid "
812 "man-in-the-middle attacks.");
813 options.forward_agent = 0;
815 if (options.forward_x11) {
816 error("X11 forwarding is disabled to avoid "
817 "man-in-the-middle attacks.");
818 options.forward_x11 = 0;
820 if (options.num_local_forwards > 0 ||
821 options.num_remote_forwards > 0) {
822 error("Port forwarding is disabled to avoid "
823 "man-in-the-middle attacks.");
824 options.num_local_forwards =
825 options.num_remote_forwards = 0;
828 * XXX Should permit the user to change to use the new id.
829 * This could be done by converting the host key to an
830 * identifying sentence, tell that the host identifies itself
831 * by that sentence, and ask the user if he/she whishes to
832 * accept the authentication.
836 fatal("internal error");
840 if (options.check_host_ip && host_status != HOST_CHANGED &&
841 ip_status == HOST_CHANGED) {
842 snprintf(msg, sizeof(msg),
843 "Warning: the %s host key for '%.200s' "
844 "differs from the key for the IP address '%.128s'"
845 "\nOffending key for IP in %s:%d",
846 type, host, ip, ip_file, ip_line);
847 if (host_status == HOST_OK) {
849 snprintf(msg + len, sizeof(msg) - len,
850 "\nMatching host key in %s:%d",
851 host_file, host_line);
853 if (options.strict_host_key_checking == 1) {
855 error("Exiting, you have requested strict checking.");
857 } else if (options.strict_host_key_checking == 2) {
858 strlcat(msg, "\nAre you sure you want "
859 "to continue connecting (yes/no)? ", sizeof(msg));
875 /* returns 0 if key verifies or -1 if key does NOT verify */
877 verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
882 if (options.verify_host_key_dns &&
883 verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
885 if (flags & DNS_VERIFY_FOUND) {
887 if (options.verify_host_key_dns == 1 &&
888 flags & DNS_VERIFY_MATCH &&
889 flags & DNS_VERIFY_SECURE)
892 if (flags & DNS_VERIFY_MATCH) {
893 matching_host_key_dns = 1;
895 warn_changed_key(host_key);
896 error("Update the SSHFP RR in DNS with the new "
897 "host key to get rid of this message.");
902 /* return ok if the key can be found in an old keyfile */
903 if (stat(options.system_hostfile2, &st) == 0 ||
904 stat(options.user_hostfile2, &st) == 0) {
905 if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1,
906 options.user_hostfile2, options.system_hostfile2) == 0)
909 return check_host_key(host, hostaddr, host_key, /*readonly*/ 0,
910 options.user_hostfile, options.system_hostfile);
914 * Starts a dialog with the server, and authenticates the current user on the
915 * server. This does not need any extra privileges. The basic connection
916 * to the server must already have been established before this is called.
917 * If login fails, this function prints an error and never returns.
918 * This function does not require super-user privileges.
921 ssh_login(Sensitive *sensitive, const char *orighost,
922 struct sockaddr *hostaddr, struct passwd *pw)
925 char *server_user, *local_user;
927 local_user = xstrdup(pw->pw_name);
928 server_user = options.user ? options.user : local_user;
930 /* Convert the user-supplied hostname into all lowercase. */
931 host = xstrdup(orighost);
932 for (cp = host; *cp; cp++)
936 /* Exchange protocol version identification strings with the server. */
937 ssh_exchange_identification();
939 /* Put the connection into non-blocking mode. */
940 packet_set_nonblocking();
943 /* authenticate user */
945 ssh_kex2(host, hostaddr);
946 ssh_userauth2(local_user, server_user, host, sensitive);
948 ssh_kex(host, hostaddr);
949 ssh_userauth1(local_user, server_user, host, sensitive);
954 ssh_put_password(char *password)
959 if (datafellows & SSH_BUG_PASSWORDPAD) {
960 packet_put_cstring(password);
963 size = roundup(strlen(password) + 1, 32);
964 padded = xmalloc(size);
965 memset(padded, 0, size);
966 strlcpy(padded, password, size);
967 packet_put_string(padded, size);
968 memset(padded, 0, size);
973 show_key_from_file(const char *file, const char *host, int keytype)
979 found = key_new(keytype);
980 if ((ret = lookup_key_in_hostfile_by_type(file, host,
981 keytype, found, &line))) {
982 fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
983 logit("WARNING: %s key found for host %s\n"
985 "%s key fingerprint %s.",
986 key_type(found), host, file, line,
987 key_type(found), fp);
994 /* print all known host keys for a given host, but skip keys of given type */
996 show_other_keys(const char *host, Key *key)
998 int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1};
1001 for (i = 0; type[i] != -1; i++) {
1002 if (type[i] == key->type)
1004 if (type[i] != KEY_RSA1 &&
1005 show_key_from_file(options.user_hostfile2, host, type[i])) {
1009 if (type[i] != KEY_RSA1 &&
1010 show_key_from_file(options.system_hostfile2, host, type[i])) {
1014 if (show_key_from_file(options.user_hostfile, host, type[i])) {
1018 if (show_key_from_file(options.system_hostfile, host, type[i])) {
1022 debug2("no key of type %d for host %s", type[i], host);
1028 warn_changed_key(Key *host_key)
1031 const char *type = key_type(host_key);
1033 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1035 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1036 error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1037 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1038 error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1039 error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1040 error("It is also possible that the %s host key has just been changed.", type);
1041 error("The fingerprint for the %s key sent by the remote host is\n%s.",
1043 error("Please contact your system administrator.");