1 /* $OpenBSD: sshconnect.c,v 1.193 2006/07/22 20:48:23 stevesk 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>
43 #include "sshconnect.h"
52 char *client_version_string = NULL;
53 char *server_version_string = NULL;
55 static int matching_host_key_dns = 0;
58 extern Options options;
59 extern char *__progname;
60 extern uid_t original_real_uid;
61 extern uid_t original_effective_uid;
62 extern pid_t proxy_command_pid;
64 #ifndef INET6_ADDRSTRLEN /* for non IPv6 machines */
65 #define INET6_ADDRSTRLEN 46
68 static int show_other_keys(const char *, Key *);
69 static void warn_changed_key(Key *);
72 * Connect to the given ssh server using a proxy command.
75 ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
77 char *command_string, *tmp;
80 char strport[NI_MAXSERV];
82 /* Convert the port number into a string. */
83 snprintf(strport, sizeof strport, "%hu", port);
86 * Build the final command string in the buffer by making the
87 * appropriate substitutions to the given proxy command.
89 * Use "exec" to avoid "sh -c" processes on some platforms
92 xasprintf(&tmp, "exec %s", proxy_command);
93 command_string = percent_expand(tmp, "h", host,
94 "p", strport, (char *)NULL);
97 /* Create pipes for communicating with the proxy. */
98 if (pipe(pin) < 0 || pipe(pout) < 0)
99 fatal("Could not create pipes to communicate with the proxy: %.100s",
102 debug("Executing proxy command: %.500s", command_string);
104 /* Fork and execute the proxy command. */
105 if ((pid = fork()) == 0) {
108 /* Child. Permanently give up superuser privileges. */
109 permanently_drop_suid(original_real_uid);
111 /* Redirect stdin and stdout. */
114 if (dup2(pin[0], 0) < 0)
115 perror("dup2 stdin");
119 if (dup2(pout[1], 1) < 0)
120 perror("dup2 stdout");
121 /* Cannot be 1 because pin allocated two descriptors. */
124 /* Stderr is left as it is so that error messages get
125 printed on the user's terminal. */
126 argv[0] = _PATH_BSHELL;
128 argv[2] = command_string;
131 /* Execute the proxy command. Note that we gave up any
132 extra privileges above. */
133 execv(argv[0], argv);
139 fatal("fork failed: %.100s", strerror(errno));
141 proxy_command_pid = pid; /* save pid to clean up later */
143 /* Close child side of the descriptors. */
147 /* Free the command name. */
148 xfree(command_string);
150 /* Set the connection file descriptors. */
151 packet_set_connection(pout[0], pin[1]);
153 /* Indicate OK return */
158 * Creates a (possibly privileged) socket for use as the ssh connection.
161 ssh_create_socket(int privileged, struct addrinfo *ai)
164 struct addrinfo hints, *res;
167 * If we are running as root and want to connect to a privileged
168 * port, bind our own socket to a privileged port.
171 int p = IPPORT_RESERVED - 1;
173 sock = rresvport_af(&p, ai->ai_family);
176 error("rresvport: af=%d %.100s", ai->ai_family,
179 debug("Allocated local port %d.", p);
182 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
184 error("socket: %.100s", strerror(errno));
186 /* Bind the socket to an alternative local IP address */
187 if (options.bind_address == NULL)
190 memset(&hints, 0, sizeof(hints));
191 hints.ai_family = ai->ai_family;
192 hints.ai_socktype = ai->ai_socktype;
193 hints.ai_protocol = ai->ai_protocol;
194 hints.ai_flags = AI_PASSIVE;
195 gaierr = getaddrinfo(options.bind_address, "0", &hints, &res);
197 error("getaddrinfo: %s: %s", options.bind_address,
198 gai_strerror(gaierr));
202 if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
203 error("bind: %s: %s", options.bind_address, strerror(errno));
213 timeout_connect(int sockfd, const struct sockaddr *serv_addr,
214 socklen_t addrlen, int timeout)
219 int optval, rc, result = -1;
222 return (connect(sockfd, serv_addr, addrlen));
224 set_nonblock(sockfd);
225 rc = connect(sockfd, serv_addr, addrlen);
227 unset_nonblock(sockfd);
230 if (errno != EINPROGRESS)
233 fdset = (fd_set *)xcalloc(howmany(sockfd + 1, NFDBITS),
235 FD_SET(sockfd, fdset);
240 rc = select(sockfd + 1, NULL, fdset, NULL, &tv);
241 if (rc != -1 || errno != EINTR)
252 debug("select: %s", strerror(errno));
255 /* Completed or failed */
257 optlen = sizeof(optval);
258 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval,
260 debug("getsockopt: %s", strerror(errno));
268 unset_nonblock(sockfd);
271 /* Should not occur */
272 fatal("Bogus return (%d) from select()", rc);
280 * Opens a TCP/IP connection to the remote server on the given host.
281 * The address of the remote host will be returned in hostaddr.
282 * If port is 0, the default port will be used. If needpriv is true,
283 * a privileged port will be allocated to make the connection.
284 * This requires super-user privileges if needpriv is true.
285 * Connection_attempts specifies the maximum number of tries (one per
286 * second). If proxy_command is non-NULL, it specifies the command (with %h
287 * and %p substituted for host and port, respectively) to use to contact
291 ssh_connect(const char *host, struct sockaddr_storage * hostaddr,
292 u_short port, int family, int connection_attempts,
293 int needpriv, const char *proxy_command)
297 int sock = -1, attempt;
298 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
299 struct addrinfo hints, *ai, *aitop;
301 debug2("ssh_connect: needpriv %d", needpriv);
303 /* If a proxy command is given, connect using it. */
304 if (proxy_command != NULL)
305 return ssh_proxy_connect(host, port, proxy_command);
307 /* No proxy command. */
309 memset(&hints, 0, sizeof(hints));
310 hints.ai_family = family;
311 hints.ai_socktype = SOCK_STREAM;
312 snprintf(strport, sizeof strport, "%u", port);
313 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
314 fatal("%s: %.100s: %s", __progname, host,
315 gai_strerror(gaierr));
317 for (attempt = 0; attempt < connection_attempts; attempt++) {
319 debug("Trying again...");
322 * Loop through addresses for this host, and try each one in
323 * sequence until the connection succeeds.
325 for (ai = aitop; ai; ai = ai->ai_next) {
326 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
328 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
329 ntop, sizeof(ntop), strport, sizeof(strport),
330 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
331 error("ssh_connect: getnameinfo failed");
334 debug("Connecting to %.200s [%.100s] port %s.",
335 host, ntop, strport);
337 /* Create a socket for connecting. */
338 sock = ssh_create_socket(needpriv, ai);
340 /* Any error is already output */
343 if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
344 options.connection_timeout) >= 0) {
345 /* Successful connection. */
346 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
349 debug("connect to address %s port %s: %s",
350 ntop, strport, strerror(errno));
356 break; /* Successful connection. */
358 /* Sleep a moment before retrying. */
364 /* Return failure if we didn't get a successful connection. */
366 error("ssh: connect to host %s port %s: %s",
367 host, strport, strerror(errno));
371 debug("Connection established.");
373 /* Set SO_KEEPALIVE if requested. */
374 if (options.tcp_keep_alive &&
375 setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
377 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
379 /* Set the connection. */
380 packet_set_connection(sock, sock);
386 * Waits for the server identification string, and sends our own
387 * identification string.
390 ssh_exchange_identification(void)
392 char buf[256], remote_version[256]; /* must be same size! */
393 int remote_major, remote_minor, mismatch;
394 int connection_in = packet_get_connection_in();
395 int connection_out = packet_get_connection_out();
396 int minor1 = PROTOCOL_MINOR_1;
399 /* Read other side's version identification. */
401 for (i = 0; i < sizeof(buf) - 1; i++) {
402 size_t len = atomicio(read, connection_in, &buf[i], 1);
404 if (len != 1 && errno == EPIPE)
405 fatal("ssh_exchange_identification: Connection closed by remote host");
407 fatal("ssh_exchange_identification: read: %.100s", strerror(errno));
408 if (buf[i] == '\r') {
411 continue; /**XXX wait for \n */
413 if (buf[i] == '\n') {
418 fatal("ssh_exchange_identification: No banner received");
420 buf[sizeof(buf) - 1] = 0;
421 if (strncmp(buf, "SSH-", 4) == 0)
423 debug("ssh_exchange_identification: %s", buf);
425 server_version_string = xstrdup(buf);
428 * Check that the versions match. In future this might accept
429 * several versions and set appropriate flags to handle them.
431 if (sscanf(server_version_string, "SSH-%d.%d-%[^\n]\n",
432 &remote_major, &remote_minor, remote_version) != 3)
433 fatal("Bad remote protocol version identification: '%.100s'", buf);
434 debug("Remote protocol version %d.%d, remote software version %.100s",
435 remote_major, remote_minor, remote_version);
437 compat_datafellows(remote_version);
440 switch (remote_major) {
442 if (remote_minor == 99 &&
443 (options.protocol & SSH_PROTO_2) &&
444 !(options.protocol & SSH_PROTO_1_PREFERRED)) {
448 if (!(options.protocol & SSH_PROTO_1)) {
452 if (remote_minor < 3) {
453 fatal("Remote machine has too old SSH software version.");
454 } else if (remote_minor == 3 || remote_minor == 4) {
455 /* We speak 1.3, too. */
458 if (options.forward_agent) {
459 logit("Agent forwarding disabled for protocol 1.3");
460 options.forward_agent = 0;
465 if (options.protocol & SSH_PROTO_2) {
475 fatal("Protocol major versions differ: %d vs. %d",
476 (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
478 /* Send our own protocol version identification. */
479 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
480 compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1,
481 compat20 ? PROTOCOL_MINOR_2 : minor1,
483 if (atomicio(vwrite, connection_out, buf, strlen(buf)) != strlen(buf))
484 fatal("write: %.100s", strerror(errno));
485 client_version_string = xstrdup(buf);
486 chop(client_version_string);
487 chop(server_version_string);
488 debug("Local version string %.100s", client_version_string);
491 /* defaults to 'no' */
493 confirm(const char *prompt)
495 const char *msg, *again = "Please type 'yes' or 'no': ";
499 if (options.batch_mode)
501 for (msg = prompt;;msg = again) {
502 p = read_passphrase(msg, RP_ECHO);
504 (p[0] == '\0') || (p[0] == '\n') ||
505 strncasecmp(p, "no", 2) == 0)
507 if (p && strncasecmp(p, "yes", 3) == 0)
517 * check whether the supplied host key is valid, return -1 if the key
518 * is not valid. the user_hostfile will not be updated if 'readonly' is true.
521 check_host_key(char *hostname, struct sockaddr *hostaddr, Key *host_key,
522 int readonly, const char *user_hostfile, const char *system_hostfile)
525 const char *type = key_type(host_key);
526 char *ip = NULL, *host = NULL;
527 char hostline[1000], *hostp, *fp;
528 HostStatus host_status;
529 HostStatus ip_status;
530 int r, local = 0, host_ip_differ = 0;
532 char ntop[NI_MAXHOST];
534 int len, host_line, ip_line;
535 const char *host_file = NULL, *ip_file = NULL;
538 * Force accepting of the host key for loopback/localhost. The
539 * problem is that if the home directory is NFS-mounted to multiple
540 * machines, localhost will refer to a different machine in each of
541 * them, and the user will get bogus HOST_CHANGED warnings. This
542 * essentially disables host authentication for localhost; however,
543 * this is probably not a real problem.
545 /** hostaddr == 0! */
546 switch (hostaddr->sa_family) {
548 local = (ntohl(((struct sockaddr_in *)hostaddr)->
549 sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
550 salen = sizeof(struct sockaddr_in);
553 local = IN6_IS_ADDR_LOOPBACK(
554 &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
555 salen = sizeof(struct sockaddr_in6);
559 salen = sizeof(struct sockaddr_storage);
562 if (options.no_host_authentication_for_localhost == 1 && local &&
563 options.host_key_alias == NULL) {
564 debug("Forcing accepting of host key for "
565 "loopback/localhost.");
570 * We don't have the remote ip-address for connections
571 * using a proxy command
573 if (options.proxy_command == NULL) {
574 if (getnameinfo(hostaddr, salen, ntop, sizeof(ntop),
575 NULL, 0, NI_NUMERICHOST) != 0)
576 fatal("check_host_key: getnameinfo failed");
577 ip = put_host_port(ntop, options.port);
579 ip = xstrdup("<no hostip for proxy command>");
582 * Turn off check_host_ip if the connection is to localhost, via proxy
583 * command or if we don't have a hostname to compare with
585 if (options.check_host_ip && (local ||
586 strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
587 options.check_host_ip = 0;
590 * Allow the user to record the key under a different name or
591 * differentiate a non-standard port. This is useful for ssh
592 * tunneling over forwarded connections or if you run multiple
593 * sshd's on different ports on the same machine.
595 if (options.host_key_alias != NULL) {
596 host = xstrdup(options.host_key_alias);
597 debug("using hostkeyalias: %s", host);
599 host = put_host_port(hostname, options.port);
603 * Store the host key from the known host file in here so that we can
604 * compare it with the key for the IP address.
606 file_key = key_new(host_key->type);
609 * Check if the host key is present in the user's list of known
610 * hosts or in the systemwide list.
612 host_file = user_hostfile;
613 host_status = check_host_in_hostfile(host_file, host, host_key,
614 file_key, &host_line);
615 if (host_status == HOST_NEW) {
616 host_file = system_hostfile;
617 host_status = check_host_in_hostfile(host_file, host, host_key,
618 file_key, &host_line);
621 * Also perform check for the ip address, skip the check if we are
622 * localhost or the hostname was an ip address to begin with
624 if (options.check_host_ip) {
625 Key *ip_key = key_new(host_key->type);
627 ip_file = user_hostfile;
628 ip_status = check_host_in_hostfile(ip_file, ip, host_key,
630 if (ip_status == HOST_NEW) {
631 ip_file = system_hostfile;
632 ip_status = check_host_in_hostfile(ip_file, ip,
633 host_key, ip_key, &ip_line);
635 if (host_status == HOST_CHANGED &&
636 (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key)))
641 ip_status = host_status;
645 switch (host_status) {
647 /* The host is known and the key matches. */
648 debug("Host '%.200s' is known and matches the %s host key.",
650 debug("Found key in %s:%d", host_file, host_line);
651 if (options.check_host_ip && ip_status == HOST_NEW) {
653 logit("%s host key for IP address "
654 "'%.128s' not in list of known hosts.",
656 else if (!add_host_to_hostfile(user_hostfile, ip,
657 host_key, options.hash_known_hosts))
658 logit("Failed to add the %s host key for IP "
659 "address '%.128s' to the list of known "
660 "hosts (%.30s).", type, ip, user_hostfile);
662 logit("Warning: Permanently added the %s host "
663 "key for IP address '%.128s' to the list "
664 "of known hosts.", type, ip);
670 /* The host is new. */
671 if (options.strict_host_key_checking == 1) {
673 * User has requested strict host key checking. We
674 * will not add the host key automatically. The only
675 * alternative left is to abort.
677 error("No %s host key is known for %.200s and you "
678 "have requested strict checking.", type, host);
680 } else if (options.strict_host_key_checking == 2) {
681 char msg1[1024], msg2[1024];
683 if (show_other_keys(host, host_key))
684 snprintf(msg1, sizeof(msg1),
685 "\nbut keys of different type are already"
686 " known for this host.");
688 snprintf(msg1, sizeof(msg1), ".");
690 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
692 if (options.verify_host_key_dns) {
693 if (matching_host_key_dns)
694 snprintf(msg2, sizeof(msg2),
695 "Matching host key fingerprint"
698 snprintf(msg2, sizeof(msg2),
699 "No matching host key fingerprint"
702 snprintf(msg, sizeof(msg),
703 "The authenticity of host '%.200s (%s)' can't be "
705 "%s key fingerprint is %s.\n%s"
706 "Are you sure you want to continue connecting "
708 host, ip, msg1, type, fp, msg2);
714 * If not in strict mode, add the key automatically to the
715 * local known_hosts file.
717 if (options.check_host_ip && ip_status == HOST_NEW) {
718 snprintf(hostline, sizeof(hostline), "%s,%s",
721 if (options.hash_known_hosts) {
722 /* Add hash of host and IP separately */
723 r = add_host_to_hostfile(user_hostfile, host,
724 host_key, options.hash_known_hosts) &&
725 add_host_to_hostfile(user_hostfile, ip,
726 host_key, options.hash_known_hosts);
728 /* Add unhashed "host,ip" */
729 r = add_host_to_hostfile(user_hostfile,
731 options.hash_known_hosts);
734 r = add_host_to_hostfile(user_hostfile, host, host_key,
735 options.hash_known_hosts);
740 logit("Failed to add the host to the list of known "
741 "hosts (%.500s).", user_hostfile);
743 logit("Warning: Permanently added '%.200s' (%s) to the "
744 "list of known hosts.", hostp, type);
747 if (options.check_host_ip && host_ip_differ) {
749 if (ip_status == HOST_NEW)
750 key_msg = "is unknown";
751 else if (ip_status == HOST_OK)
752 key_msg = "is unchanged";
754 key_msg = "has a different value";
755 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
756 error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
757 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
758 error("The %s host key for %s has changed,", type, host);
759 error("and the key for the according IP address %s", ip);
760 error("%s. This could either mean that", key_msg);
761 error("DNS SPOOFING is happening or the IP address for the host");
762 error("and its host key have changed at the same time.");
763 if (ip_status != HOST_NEW)
764 error("Offending key for IP in %s:%d", ip_file, ip_line);
766 /* The host key has changed. */
767 warn_changed_key(host_key);
768 error("Add correct host key in %.100s to get rid of this message.",
770 error("Offending key in %s:%d", host_file, host_line);
773 * If strict host key checking is in use, the user will have
774 * to edit the key manually and we can only abort.
776 if (options.strict_host_key_checking) {
777 error("%s host key for %.200s has changed and you have "
778 "requested strict checking.", type, host);
783 * If strict host key checking has not been requested, allow
784 * the connection but without MITM-able authentication or
787 if (options.password_authentication) {
788 error("Password authentication is disabled to avoid "
789 "man-in-the-middle attacks.");
790 options.password_authentication = 0;
792 if (options.kbd_interactive_authentication) {
793 error("Keyboard-interactive authentication is disabled"
794 " to avoid man-in-the-middle attacks.");
795 options.kbd_interactive_authentication = 0;
796 options.challenge_response_authentication = 0;
798 if (options.challenge_response_authentication) {
799 error("Challenge/response authentication is disabled"
800 " to avoid man-in-the-middle attacks.");
801 options.challenge_response_authentication = 0;
803 if (options.forward_agent) {
804 error("Agent forwarding is disabled to avoid "
805 "man-in-the-middle attacks.");
806 options.forward_agent = 0;
808 if (options.forward_x11) {
809 error("X11 forwarding is disabled to avoid "
810 "man-in-the-middle attacks.");
811 options.forward_x11 = 0;
813 if (options.num_local_forwards > 0 ||
814 options.num_remote_forwards > 0) {
815 error("Port forwarding is disabled to avoid "
816 "man-in-the-middle attacks.");
817 options.num_local_forwards =
818 options.num_remote_forwards = 0;
821 * XXX Should permit the user to change to use the new id.
822 * This could be done by converting the host key to an
823 * identifying sentence, tell that the host identifies itself
824 * by that sentence, and ask the user if he/she whishes to
825 * accept the authentication.
829 fatal("internal error");
833 if (options.check_host_ip && host_status != HOST_CHANGED &&
834 ip_status == HOST_CHANGED) {
835 snprintf(msg, sizeof(msg),
836 "Warning: the %s host key for '%.200s' "
837 "differs from the key for the IP address '%.128s'"
838 "\nOffending key for IP in %s:%d",
839 type, host, ip, ip_file, ip_line);
840 if (host_status == HOST_OK) {
842 snprintf(msg + len, sizeof(msg) - len,
843 "\nMatching host key in %s:%d",
844 host_file, host_line);
846 if (options.strict_host_key_checking == 1) {
848 error("Exiting, you have requested strict checking.");
850 } else if (options.strict_host_key_checking == 2) {
851 strlcat(msg, "\nAre you sure you want "
852 "to continue connecting (yes/no)? ", sizeof(msg));
870 /* returns 0 if key verifies or -1 if key does NOT verify */
872 verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key)
877 if (options.verify_host_key_dns &&
878 verify_host_key_dns(host, hostaddr, host_key, &flags) == 0) {
880 if (flags & DNS_VERIFY_FOUND) {
882 if (options.verify_host_key_dns == 1 &&
883 flags & DNS_VERIFY_MATCH &&
884 flags & DNS_VERIFY_SECURE)
887 if (flags & DNS_VERIFY_MATCH) {
888 matching_host_key_dns = 1;
890 warn_changed_key(host_key);
891 error("Update the SSHFP RR in DNS with the new "
892 "host key to get rid of this message.");
897 /* return ok if the key can be found in an old keyfile */
898 if (stat(options.system_hostfile2, &st) == 0 ||
899 stat(options.user_hostfile2, &st) == 0) {
900 if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1,
901 options.user_hostfile2, options.system_hostfile2) == 0)
904 return check_host_key(host, hostaddr, host_key, /*readonly*/ 0,
905 options.user_hostfile, options.system_hostfile);
909 * Starts a dialog with the server, and authenticates the current user on the
910 * server. This does not need any extra privileges. The basic connection
911 * to the server must already have been established before this is called.
912 * If login fails, this function prints an error and never returns.
913 * This function does not require super-user privileges.
916 ssh_login(Sensitive *sensitive, const char *orighost,
917 struct sockaddr *hostaddr, struct passwd *pw)
920 char *server_user, *local_user;
922 local_user = xstrdup(pw->pw_name);
923 server_user = options.user ? options.user : local_user;
925 /* Convert the user-supplied hostname into all lowercase. */
926 host = xstrdup(orighost);
927 for (cp = host; *cp; cp++)
929 *cp = (char)tolower(*cp);
931 /* Exchange protocol version identification strings with the server. */
932 ssh_exchange_identification();
934 /* Put the connection into non-blocking mode. */
935 packet_set_nonblocking();
938 /* authenticate user */
940 ssh_kex2(host, hostaddr);
941 ssh_userauth2(local_user, server_user, host, sensitive);
943 ssh_kex(host, hostaddr);
944 ssh_userauth1(local_user, server_user, host, sensitive);
950 ssh_put_password(char *password)
955 if (datafellows & SSH_BUG_PASSWORDPAD) {
956 packet_put_cstring(password);
959 size = roundup(strlen(password) + 1, 32);
960 padded = xcalloc(1, size);
961 strlcpy(padded, password, size);
962 packet_put_string(padded, size);
963 memset(padded, 0, size);
968 show_key_from_file(const char *file, const char *host, int keytype)
974 found = key_new(keytype);
975 if ((ret = lookup_key_in_hostfile_by_type(file, host,
976 keytype, found, &line))) {
977 fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
978 logit("WARNING: %s key found for host %s\n"
980 "%s key fingerprint %s.",
981 key_type(found), host, file, line,
982 key_type(found), fp);
989 /* print all known host keys for a given host, but skip keys of given type */
991 show_other_keys(const char *host, Key *key)
993 int type[] = { KEY_RSA1, KEY_RSA, KEY_DSA, -1};
996 for (i = 0; type[i] != -1; i++) {
997 if (type[i] == key->type)
999 if (type[i] != KEY_RSA1 &&
1000 show_key_from_file(options.user_hostfile2, host, type[i])) {
1004 if (type[i] != KEY_RSA1 &&
1005 show_key_from_file(options.system_hostfile2, host, type[i])) {
1009 if (show_key_from_file(options.user_hostfile, host, type[i])) {
1013 if (show_key_from_file(options.system_hostfile, host, type[i])) {
1017 debug2("no key of type %d for host %s", type[i], host);
1023 warn_changed_key(Key *host_key)
1026 const char *type = key_type(host_key);
1028 fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX);
1030 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1031 error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1032 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1033 error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1034 error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1035 error("It is also possible that the %s host key has just been changed.", type);
1036 error("The fingerprint for the %s key sent by the remote host is\n%s.",
1038 error("Please contact your system administrator.");
1044 * Execute a local command
1047 ssh_local_cmd(const char *args)
1053 if (!options.permit_local_command ||
1054 args == NULL || !*args)
1057 if ((shell = getenv("SHELL")) == NULL)
1058 shell = _PATH_BSHELL;
1062 debug3("Executing %s -c \"%s\"", shell, args);
1063 execl(shell, shell, "-c", args, (char *)NULL);
1064 error("Couldn't execute %s -c \"%s\": %s",
1065 shell, args, strerror(errno));
1067 } else if (pid == -1)
1068 fatal("fork failed: %.100s", strerror(errno));
1069 while (waitpid(pid, &status, 0) == -1)
1071 fatal("Couldn't wait for child: %s", strerror(errno));
1073 if (!WIFEXITED(status))
1076 return (WEXITSTATUS(status));