1 /* $OpenBSD: sshconnect.c,v 1.363 2023/03/10 07:17:08 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>
22 #ifdef HAVE_SYS_TIME_H
23 # include <sys/time.h>
27 #include <netinet/in.h>
28 #include <arpa/inet.h>
58 #include "sshconnect.h"
64 #include "monitor_fdpass.h"
72 struct sshkey *previous_host_key = NULL;
74 static int matching_host_key_dns = 0;
76 static pid_t proxy_command_pid = 0;
79 extern int debug_flag;
80 extern Options options;
81 extern char *__progname;
83 static int show_other_keys(struct hostkeys *, struct sshkey *);
84 static void warn_changed_key(struct sshkey *);
86 /* Expand a proxy command */
88 expand_proxy_command(const char *proxy_command, const char *user,
89 const char *host, const char *host_arg, int port)
91 char *tmp, *ret, strport[NI_MAXSERV];
92 const char *keyalias = options.host_key_alias ?
93 options.host_key_alias : host_arg;
95 snprintf(strport, sizeof strport, "%d", port);
96 xasprintf(&tmp, "exec %s", proxy_command);
97 ret = percent_expand(tmp,
109 * Connect to the given ssh server using a proxy command that passes a
110 * a connected fd back to us.
113 ssh_proxy_fdpass_connect(struct ssh *ssh, const char *host,
114 const char *host_arg, u_short port, const char *proxy_command)
116 char *command_string;
121 if ((shell = getenv("SHELL")) == NULL)
122 shell = _PATH_BSHELL;
124 if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) == -1)
125 fatal("Could not create socketpair to communicate with "
126 "proxy dialer: %.100s", strerror(errno));
128 command_string = expand_proxy_command(proxy_command, options.user,
129 host, host_arg, port);
130 debug("Executing proxy dialer command: %.500s", command_string);
132 /* Fork and execute the proxy command. */
133 if ((pid = fork()) == 0) {
137 /* Redirect stdin and stdout. */
139 if (dup2(sp[0], 0) == -1)
140 perror("dup2 stdin");
143 if (dup2(sp[0], 1) == -1)
144 perror("dup2 stdout");
150 * Stderr is left for non-ControlPersist connections is so
151 * error messages may be printed on the user's terminal.
153 if (!debug_flag && options.control_path != NULL &&
154 options.control_persist && stdfd_devnull(0, 0, 1) == -1)
155 error_f("stdfd_devnull failed");
159 argv[2] = command_string;
163 * Execute the proxy command.
164 * Note that we gave up any extra privileges above.
166 execv(argv[0], argv);
172 fatal("fork failed: %.100s", strerror(errno));
174 free(command_string);
176 if ((sock = mm_receive_fd(sp[1])) == -1)
177 fatal("proxy dialer did not pass back a connection");
180 while (waitpid(pid, NULL, 0) == -1)
182 fatal("Couldn't wait for child: %s", strerror(errno));
184 /* Set the connection file descriptors. */
185 if (ssh_packet_set_connection(ssh, sock, sock) == NULL)
186 return -1; /* ssh_packet_set_connection logs error */
192 * Connect to the given ssh server using a proxy command.
195 ssh_proxy_connect(struct ssh *ssh, const char *host, const char *host_arg,
196 u_short port, const char *proxy_command)
198 char *command_string;
203 if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
204 shell = _PATH_BSHELL;
206 /* Create pipes for communicating with the proxy. */
207 if (pipe(pin) == -1 || pipe(pout) == -1)
208 fatal("Could not create pipes to communicate with the proxy: %.100s",
211 command_string = expand_proxy_command(proxy_command, options.user,
212 host, host_arg, port);
213 debug("Executing proxy command: %.500s", command_string);
215 /* Fork and execute the proxy command. */
216 if ((pid = fork()) == 0) {
219 /* Redirect stdin and stdout. */
222 if (dup2(pin[0], 0) == -1)
223 perror("dup2 stdin");
227 if (dup2(pout[1], 1) == -1)
228 perror("dup2 stdout");
229 /* Cannot be 1 because pin allocated two descriptors. */
233 * Stderr is left for non-ControlPersist connections is so
234 * error messages may be printed on the user's terminal.
236 if (!debug_flag && options.control_path != NULL &&
237 options.control_persist && stdfd_devnull(0, 0, 1) == -1)
238 error_f("stdfd_devnull failed");
242 argv[2] = command_string;
246 * Execute the proxy command. Note that we gave up any
247 * extra privileges above.
249 ssh_signal(SIGPIPE, SIG_DFL);
250 execv(argv[0], argv);
256 fatal("fork failed: %.100s", strerror(errno));
258 proxy_command_pid = pid; /* save pid to clean up later */
260 /* Close child side of the descriptors. */
264 /* Free the command name. */
265 free(command_string);
267 /* Set the connection file descriptors. */
268 if (ssh_packet_set_connection(ssh, pout[0], pin[1]) == NULL)
269 return -1; /* ssh_packet_set_connection logs error */
275 ssh_kill_proxy_command(void)
278 * Send SIGHUP to proxy command if used. We don't wait() in
279 * case it hangs and instead rely on init to reap the child
281 if (proxy_command_pid > 1)
282 kill(proxy_command_pid, SIGHUP);
285 #ifdef HAVE_IFADDRS_H
287 * Search a interface address list (returned from getifaddrs(3)) for an
288 * address that matches the desired address family on the specified interface.
289 * Returns 0 and fills in *resultp and *rlenp on success. Returns -1 on failure.
292 check_ifaddrs(const char *ifname, int af, const struct ifaddrs *ifaddrs,
293 struct sockaddr_storage *resultp, socklen_t *rlenp)
295 struct sockaddr_in6 *sa6;
296 struct sockaddr_in *sa;
297 struct in6_addr *v6addr;
298 const struct ifaddrs *ifa;
302 * Prefer addresses that are not loopback or linklocal, but use them
303 * if nothing else matches.
305 for (allow_local = 0; allow_local < 2; allow_local++) {
306 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
307 if (ifa->ifa_addr == NULL || ifa->ifa_name == NULL ||
308 (ifa->ifa_flags & IFF_UP) == 0 ||
309 ifa->ifa_addr->sa_family != af ||
310 strcmp(ifa->ifa_name, options.bind_interface) != 0)
312 switch (ifa->ifa_addr->sa_family) {
314 sa = (struct sockaddr_in *)ifa->ifa_addr;
315 if (!allow_local && sa->sin_addr.s_addr ==
316 htonl(INADDR_LOOPBACK))
318 if (*rlenp < sizeof(struct sockaddr_in)) {
319 error_f("v4 addr doesn't fit");
322 *rlenp = sizeof(struct sockaddr_in);
323 memcpy(resultp, sa, *rlenp);
326 sa6 = (struct sockaddr_in6 *)ifa->ifa_addr;
327 v6addr = &sa6->sin6_addr;
329 (IN6_IS_ADDR_LINKLOCAL(v6addr) ||
330 IN6_IS_ADDR_LOOPBACK(v6addr)))
332 if (*rlenp < sizeof(struct sockaddr_in6)) {
333 error_f("v6 addr doesn't fit");
336 *rlenp = sizeof(struct sockaddr_in6);
337 memcpy(resultp, sa6, *rlenp);
347 * Creates a socket for use as the ssh connection.
350 ssh_create_socket(struct addrinfo *ai)
353 struct sockaddr_storage bindaddr;
354 socklen_t bindaddrlen = 0;
355 struct addrinfo hints, *res = NULL;
356 #ifdef HAVE_IFADDRS_H
357 struct ifaddrs *ifaddrs = NULL;
359 char ntop[NI_MAXHOST];
361 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
363 error("socket: %s", strerror(errno));
366 (void)fcntl(sock, F_SETFD, FD_CLOEXEC);
368 /* Use interactive QOS (if specified) until authentication completed */
369 if (options.ip_qos_interactive != INT_MAX)
370 set_sock_tos(sock, options.ip_qos_interactive);
372 /* Bind the socket to an alternative local IP address */
373 if (options.bind_address == NULL && options.bind_interface == NULL)
376 if (options.bind_address != NULL) {
377 memset(&hints, 0, sizeof(hints));
378 hints.ai_family = ai->ai_family;
379 hints.ai_socktype = ai->ai_socktype;
380 hints.ai_protocol = ai->ai_protocol;
381 hints.ai_flags = AI_PASSIVE;
382 if ((r = getaddrinfo(options.bind_address, NULL,
383 &hints, &res)) != 0) {
384 error("getaddrinfo: %s: %s", options.bind_address,
385 ssh_gai_strerror(r));
389 error("getaddrinfo: no addrs");
392 memcpy(&bindaddr, res->ai_addr, res->ai_addrlen);
393 bindaddrlen = res->ai_addrlen;
394 } else if (options.bind_interface != NULL) {
395 #ifdef HAVE_IFADDRS_H
396 if ((r = getifaddrs(&ifaddrs)) != 0) {
397 error("getifaddrs: %s: %s", options.bind_interface,
401 bindaddrlen = sizeof(bindaddr);
402 if (check_ifaddrs(options.bind_interface, ai->ai_family,
403 ifaddrs, &bindaddr, &bindaddrlen) != 0) {
404 logit("getifaddrs: %s: no suitable addresses",
405 options.bind_interface);
409 error("BindInterface not supported on this platform.");
412 if ((r = getnameinfo((struct sockaddr *)&bindaddr, bindaddrlen,
413 ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST)) != 0) {
414 error_f("getnameinfo failed: %s", ssh_gai_strerror(r));
417 if (bind(sock, (struct sockaddr *)&bindaddr, bindaddrlen) != 0) {
418 error("bind %s: %s", ntop, strerror(errno));
421 debug_f("bound to %s", ntop);
430 #ifdef HAVE_IFADDRS_H
432 freeifaddrs(ifaddrs);
438 * Opens a TCP/IP connection to the remote server on the given host.
439 * The address of the remote host will be returned in hostaddr.
440 * If port is 0, the default port will be used.
441 * Connection_attempts specifies the maximum number of tries (one per
442 * second). If proxy_command is non-NULL, it specifies the command (with %h
443 * and %p substituted for host and port, respectively) to use to contact
447 ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
448 struct sockaddr_storage *hostaddr, u_short port, int connection_attempts,
449 int *timeout_ms, int want_keepalive)
451 int on = 1, saved_timeout_ms = *timeout_ms;
452 int oerrno, sock = -1, attempt;
453 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
456 debug3_f("entering");
457 memset(ntop, 0, sizeof(ntop));
458 memset(strport, 0, sizeof(strport));
460 for (attempt = 0; attempt < connection_attempts; attempt++) {
462 /* Sleep a moment before retrying. */
464 debug("Trying again...");
467 * Loop through addresses for this host, and try each one in
468 * sequence until the connection succeeds.
470 for (ai = aitop; ai; ai = ai->ai_next) {
471 if (ai->ai_family != AF_INET &&
472 ai->ai_family != AF_INET6) {
473 errno = EAFNOSUPPORT;
476 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
477 ntop, sizeof(ntop), strport, sizeof(strport),
478 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
480 error_f("getnameinfo failed");
484 debug("Connecting to %.200s [%.100s] port %s.",
485 host, ntop, strport);
487 /* Create a socket for connecting. */
488 sock = ssh_create_socket(ai);
490 /* Any error is already output */
495 *timeout_ms = saved_timeout_ms;
496 if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
498 /* Successful connection. */
499 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
503 debug("connect to address %s port %s: %s",
504 ntop, strport, strerror(errno));
511 break; /* Successful connection. */
514 /* Return failure if we didn't get a successful connection. */
516 error("ssh: connect to host %s port %s: %s",
517 host, strport, errno == 0 ? "failure" : strerror(errno));
521 debug("Connection established.");
523 /* Set SO_KEEPALIVE if requested. */
524 if (want_keepalive &&
525 setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
527 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
529 /* Set the connection. */
530 if (ssh_packet_set_connection(ssh, sock, sock) == NULL)
531 return -1; /* ssh_packet_set_connection logs error */
537 ssh_connect(struct ssh *ssh, const char *host, const char *host_arg,
538 struct addrinfo *addrs, struct sockaddr_storage *hostaddr, u_short port,
539 int connection_attempts, int *timeout_ms, int want_keepalive)
543 if (options.proxy_command == NULL) {
544 return ssh_connect_direct(ssh, host, addrs, hostaddr, port,
545 connection_attempts, timeout_ms, want_keepalive);
546 } else if (strcmp(options.proxy_command, "-") == 0) {
547 if ((in = dup(STDIN_FILENO)) == -1 ||
548 (out = dup(STDOUT_FILENO)) == -1) {
551 error_f("dup() in/out failed");
552 return -1; /* ssh_packet_set_connection logs error */
554 if ((ssh_packet_set_connection(ssh, in, out)) == NULL)
555 return -1; /* ssh_packet_set_connection logs error */
557 } else if (options.proxy_use_fdpass) {
558 return ssh_proxy_fdpass_connect(ssh, host, host_arg, port,
559 options.proxy_command);
561 return ssh_proxy_connect(ssh, host, host_arg, port,
562 options.proxy_command);
565 /* defaults to 'no' */
567 confirm(const char *prompt, const char *fingerprint)
569 const char *msg, *again = "Please type 'yes' or 'no': ";
570 const char *again_fp = "Please type 'yes', 'no' or the fingerprint: ";
574 if (options.batch_mode)
576 for (msg = prompt;;msg = fingerprint ? again_fp : again) {
577 cp = p = read_passphrase(msg, RP_ECHO);
580 p += strspn(p, " \t"); /* skip leading whitespace */
581 p[strcspn(p, " \t\n")] = '\0'; /* remove trailing whitespace */
582 if (p[0] == '\0' || strcasecmp(p, "no") == 0)
584 else if (strcasecmp(p, "yes") == 0 || (fingerprint != NULL &&
585 strcmp(p, fingerprint) == 0))
594 sockaddr_is_local(struct sockaddr *hostaddr)
596 switch (hostaddr->sa_family) {
598 return (ntohl(((struct sockaddr_in *)hostaddr)->
599 sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
601 return IN6_IS_ADDR_LOOPBACK(
602 &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
609 * Prepare the hostname and ip address strings that are used to lookup
610 * host keys in known_hosts files. These may have a port number appended.
613 get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr,
614 u_short port, char **hostfile_hostname, char **hostfile_ipaddr)
616 char ntop[NI_MAXHOST];
619 switch (hostaddr == NULL ? -1 : hostaddr->sa_family) {
624 addrlen = sizeof(struct sockaddr_in);
627 addrlen = sizeof(struct sockaddr_in6);
630 addrlen = sizeof(struct sockaddr);
635 * We don't have the remote ip-address for connections
636 * using a proxy command
638 if (hostfile_ipaddr != NULL) {
639 if (options.proxy_command == NULL) {
640 if (getnameinfo(hostaddr, addrlen,
641 ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST) != 0)
642 fatal_f("getnameinfo failed");
643 *hostfile_ipaddr = put_host_port(ntop, port);
645 *hostfile_ipaddr = xstrdup("<no hostip for proxy "
651 * Allow the user to record the key under a different name or
652 * differentiate a non-standard port. This is useful for ssh
653 * tunneling over forwarded connections or if you run multiple
654 * sshd's on different ports on the same machine.
656 if (hostfile_hostname != NULL) {
657 if (options.host_key_alias != NULL) {
658 *hostfile_hostname = xstrdup(options.host_key_alias);
659 debug("using hostkeyalias: %s", *hostfile_hostname);
661 *hostfile_hostname = put_host_port(hostname, port);
666 /* returns non-zero if path appears in hostfiles, or 0 if not. */
668 path_in_hostfiles(const char *path, char **hostfiles, u_int num_hostfiles)
672 for (i = 0; i < num_hostfiles; i++) {
673 if (strcmp(path, hostfiles[i]) == 0)
679 struct find_by_key_ctx {
680 const char *host, *ip;
681 const struct sshkey *key;
686 /* Try to replace home directory prefix (per $HOME) with a ~/ sequence */
688 try_tilde_unexpand(const char *path)
690 char *home, *ret = NULL;
694 return xstrdup(path);
695 if ((home = getenv("HOME")) == NULL || (l = strlen(home)) == 0)
696 return xstrdup(path);
697 if (strncmp(path, home, l) != 0)
698 return xstrdup(path);
700 * ensure we have matched on a path boundary: either the $HOME that
701 * we just compared ends with a '/' or the next character of the path
704 if (home[l - 1] != '/' && path[l] != '/')
705 return xstrdup(path);
708 xasprintf(&ret, "~/%s", path + l);
713 hostkeys_find_by_key_cb(struct hostkey_foreach_line *l, void *_ctx)
715 struct find_by_key_ctx *ctx = (struct find_by_key_ctx *)_ctx;
718 /* we are looking for keys with names that *do not* match */
719 if ((l->match & HKF_MATCH_HOST) != 0)
721 /* not interested in marker lines */
722 if (l->marker != MRK_NONE)
724 /* we are only interested in exact key matches */
725 if (l->key == NULL || !sshkey_equal(ctx->key, l->key))
727 path = try_tilde_unexpand(l->path);
728 debug_f("found matching key in %s:%lu", path, l->linenum);
729 ctx->names = xrecallocarray(ctx->names,
730 ctx->nnames, ctx->nnames + 1, sizeof(*ctx->names));
731 xasprintf(&ctx->names[ctx->nnames], "%s:%lu: %s", path, l->linenum,
732 strncmp(l->hosts, HASH_MAGIC, strlen(HASH_MAGIC)) == 0 ?
733 "[hashed name]" : l->hosts);
740 hostkeys_find_by_key_hostfile(const char *file, const char *which,
741 struct find_by_key_ctx *ctx)
745 debug3_f("trying %s hostfile \"%s\"", which, file);
746 if ((r = hostkeys_foreach(file, hostkeys_find_by_key_cb, ctx,
747 ctx->host, ctx->ip, HKF_WANT_PARSE_KEY, 0)) != 0) {
748 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
749 debug_f("hostkeys file %s does not exist", file);
752 error_fr(r, "hostkeys_foreach failed for %s", file);
759 * Find 'key' in known hosts file(s) that do not match host/ip.
760 * Used to display also-known-as information for previously-unseen hostkeys.
763 hostkeys_find_by_key(const char *host, const char *ip, const struct sshkey *key,
764 char **user_hostfiles, u_int num_user_hostfiles,
765 char **system_hostfiles, u_int num_system_hostfiles,
766 char ***names, u_int *nnames)
768 struct find_by_key_ctx ctx = {0, 0, 0, 0, 0};
774 if (key == NULL || sshkey_is_cert(key))
781 for (i = 0; i < num_user_hostfiles; i++) {
782 if (hostkeys_find_by_key_hostfile(user_hostfiles[i],
786 for (i = 0; i < num_system_hostfiles; i++) {
787 if (hostkeys_find_by_key_hostfile(system_hostfiles[i],
788 "system", &ctx) != 0)
793 *nnames = ctx.nnames;
798 for (i = 0; i < ctx.nnames; i++)
803 #define MAX_OTHER_NAMES 8 /* Maximum number of names to list */
805 other_hostkeys_message(const char *host, const char *ip,
806 const struct sshkey *key,
807 char **user_hostfiles, u_int num_user_hostfiles,
808 char **system_hostfiles, u_int num_system_hostfiles)
810 char *ret = NULL, **othernames = NULL;
811 u_int i, n, num_othernames = 0;
813 hostkeys_find_by_key(host, ip, key,
814 user_hostfiles, num_user_hostfiles,
815 system_hostfiles, num_system_hostfiles,
816 &othernames, &num_othernames);
817 if (num_othernames == 0)
818 return xstrdup("This key is not known by any other names.");
820 xasprintf(&ret, "This host key is known by the following other "
824 if (n > MAX_OTHER_NAMES)
826 for (i = 0; i < n; i++) {
827 xextendf(&ret, "\n", " %s", othernames[i]);
829 if (n < num_othernames) {
830 xextendf(&ret, "\n", " (%d additional names omitted)",
833 for (i = 0; i < num_othernames; i++)
840 load_hostkeys_command(struct hostkeys *hostkeys, const char *command_template,
841 const char *invocation, const struct ssh_conn_info *cinfo,
842 const struct sshkey *host_key, const char *hostfile_hostname)
845 char *key_fp = NULL, *keytext = NULL, *tmp;
846 char *command = NULL, *tag = NULL, **av = NULL;
849 void (*osigchld)(int);
851 xasprintf(&tag, "KnownHostsCommand-%s", invocation);
853 if (host_key != NULL) {
854 if ((key_fp = sshkey_fingerprint(host_key,
855 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
856 fatal_f("sshkey_fingerprint failed");
857 if ((r = sshkey_to_base64(host_key, &keytext)) != 0)
858 fatal_fr(r, "sshkey_to_base64 failed");
861 * NB. all returns later this function should go via "out" to
862 * ensure the original SIGCHLD handler is restored properly.
864 osigchld = ssh_signal(SIGCHLD, SIG_DFL);
866 /* Turn the command into an argument vector */
867 if (argv_split(command_template, &ac, &av, 0) != 0) {
868 error("%s \"%s\" contains invalid quotes", tag,
873 error("%s \"%s\" yielded no arguments", tag,
877 for (i = 1; i < ac; i++) {
878 tmp = percent_dollar_expand(av[i],
879 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
880 "H", hostfile_hostname,
882 "t", host_key == NULL ? "NONE" : sshkey_ssh_name(host_key),
883 "f", key_fp == NULL ? "NONE" : key_fp,
884 "K", keytext == NULL ? "NONE" : keytext,
887 fatal_f("percent_expand failed");
891 /* Prepare a printable command for logs, etc. */
892 command = argv_assemble(ac, av);
894 if ((pid = subprocess(tag, command, ac, av, &f,
895 SSH_SUBPROCESS_STDOUT_CAPTURE|SSH_SUBPROCESS_UNSAFE_PATH|
896 SSH_SUBPROCESS_PRESERVE_ENV, NULL, NULL, NULL)) == 0)
899 load_hostkeys_file(hostkeys, hostfile_hostname, tag, f, 1);
901 if (exited_cleanly(pid, tag, command, 0) != 0)
902 fatal("KnownHostsCommand failed");
907 ssh_signal(SIGCHLD, osigchld);
908 for (i = 0; i < ac; i++)
918 * check whether the supplied host key is valid, return -1 if the key
919 * is not valid. user_hostfile[0] will not be updated if 'readonly' is true.
925 check_host_key(char *hostname, const struct ssh_conn_info *cinfo,
926 struct sockaddr *hostaddr, u_short port,
927 struct sshkey *host_key, int readonly, int clobber_port,
928 char **user_hostfiles, u_int num_user_hostfiles,
929 char **system_hostfiles, u_int num_system_hostfiles,
930 const char *hostfile_command)
932 HostStatus host_status = -1, ip_status = -1;
933 struct sshkey *raw_key = NULL;
934 char *ip = NULL, *host = NULL;
935 char hostline[1000], *hostp, *fp, *ra;
937 const char *type, *fail_reason = NULL;
938 const struct hostkey_entry *host_found = NULL, *ip_found = NULL;
939 int len, cancelled_forwarding = 0, confirmed;
940 int local = sockaddr_is_local(hostaddr);
941 int r, want_cert = sshkey_is_cert(host_key), host_ip_differ = 0;
942 int hostkey_trusted = 0; /* Known or explicitly accepted by user */
943 struct hostkeys *host_hostkeys, *ip_hostkeys;
947 * Force accepting of the host key for loopback/localhost. The
948 * problem is that if the home directory is NFS-mounted to multiple
949 * machines, localhost will refer to a different machine in each of
950 * them, and the user will get bogus HOST_CHANGED warnings. This
951 * essentially disables host authentication for localhost; however,
952 * this is probably not a real problem.
954 if (options.no_host_authentication_for_localhost == 1 && local &&
955 options.host_key_alias == NULL) {
956 debug("Forcing accepting of host key for "
957 "loopback/localhost.");
958 options.update_hostkeys = 0;
963 * Don't ever try to write an invalid name to a known hosts file.
964 * Note: do this before get_hostfile_hostname_ipaddr() to catch
965 * '[' or ']' in the name before they are added.
967 if (strcspn(hostname, "@?*#[]|'\'\"\\") != strlen(hostname)) {
968 debug_f("invalid hostname \"%s\"; will not record: %s",
969 hostname, fail_reason);
974 * Prepare the hostname and address strings used for hostkey lookup.
975 * In some cases, these will have a port number appended.
977 get_hostfile_hostname_ipaddr(hostname, hostaddr,
978 clobber_port ? 0 : port, &host, &ip);
981 * Turn off check_host_ip if the connection is to localhost, via proxy
982 * command or if we don't have a hostname to compare with
984 if (options.check_host_ip && (local ||
985 strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
986 options.check_host_ip = 0;
988 host_hostkeys = init_hostkeys();
989 for (i = 0; i < num_user_hostfiles; i++)
990 load_hostkeys(host_hostkeys, host, user_hostfiles[i], 0);
991 for (i = 0; i < num_system_hostfiles; i++)
992 load_hostkeys(host_hostkeys, host, system_hostfiles[i], 0);
993 if (hostfile_command != NULL && !clobber_port) {
994 load_hostkeys_command(host_hostkeys, hostfile_command,
995 "HOSTNAME", cinfo, host_key, host);
999 if (!want_cert && options.check_host_ip) {
1000 ip_hostkeys = init_hostkeys();
1001 for (i = 0; i < num_user_hostfiles; i++)
1002 load_hostkeys(ip_hostkeys, ip, user_hostfiles[i], 0);
1003 for (i = 0; i < num_system_hostfiles; i++)
1004 load_hostkeys(ip_hostkeys, ip, system_hostfiles[i], 0);
1005 if (hostfile_command != NULL && !clobber_port) {
1006 load_hostkeys_command(ip_hostkeys, hostfile_command,
1007 "ADDRESS", cinfo, host_key, ip);
1012 /* Reload these as they may have changed on cert->key downgrade */
1013 want_cert = sshkey_is_cert(host_key);
1014 type = sshkey_type(host_key);
1017 * Check if the host key is present in the user's list of known
1018 * hosts or in the systemwide list.
1020 host_status = check_key_in_hostkeys(host_hostkeys, host_key,
1024 * If there are no hostfiles, or if the hostkey was found via
1025 * KnownHostsCommand, then don't try to touch the disk.
1027 if (!readonly && (num_user_hostfiles == 0 ||
1028 (host_found != NULL && host_found->note != 0)))
1032 * Also perform check for the ip address, skip the check if we are
1033 * localhost, looking for a certificate, or the hostname was an ip
1034 * address to begin with.
1036 if (!want_cert && ip_hostkeys != NULL) {
1037 ip_status = check_key_in_hostkeys(ip_hostkeys, host_key,
1039 if (host_status == HOST_CHANGED &&
1040 (ip_status != HOST_CHANGED ||
1041 (ip_found != NULL &&
1042 !sshkey_equal(ip_found->key, host_found->key))))
1045 ip_status = host_status;
1047 switch (host_status) {
1049 /* The host is known and the key matches. */
1050 debug("Host '%.200s' is known and matches the %s host %s.",
1051 host, type, want_cert ? "certificate" : "key");
1052 debug("Found %s in %s:%lu", want_cert ? "CA key" : "key",
1053 host_found->file, host_found->line);
1055 if (sshkey_cert_check_host(host_key,
1056 options.host_key_alias == NULL ?
1057 hostname : options.host_key_alias, 0,
1058 options.ca_sign_algorithms, &fail_reason) != 0) {
1059 error("%s", fail_reason);
1063 * Do not attempt hostkey update if a certificate was
1064 * successfully matched.
1066 if (options.update_hostkeys != 0) {
1067 options.update_hostkeys = 0;
1068 debug3_f("certificate host key in use; "
1069 "disabling UpdateHostkeys");
1072 /* Turn off UpdateHostkeys if key was in system known_hosts */
1073 if (options.update_hostkeys != 0 &&
1074 (path_in_hostfiles(host_found->file,
1075 system_hostfiles, num_system_hostfiles) ||
1076 (ip_status == HOST_OK && ip_found != NULL &&
1077 path_in_hostfiles(ip_found->file,
1078 system_hostfiles, num_system_hostfiles)))) {
1079 options.update_hostkeys = 0;
1080 debug3_f("host key found in GlobalKnownHostsFile; "
1081 "disabling UpdateHostkeys");
1083 if (options.update_hostkeys != 0 && host_found->note) {
1084 options.update_hostkeys = 0;
1085 debug3_f("host key found via KnownHostsCommand; "
1086 "disabling UpdateHostkeys");
1088 if (options.check_host_ip && ip_status == HOST_NEW) {
1089 if (readonly || want_cert)
1090 logit("%s host key for IP address "
1091 "'%.128s' not in list of known hosts.",
1093 else if (!add_host_to_hostfile(user_hostfiles[0], ip,
1094 host_key, options.hash_known_hosts))
1095 logit("Failed to add the %s host key for IP "
1096 "address '%.128s' to the list of known "
1097 "hosts (%.500s).", type, ip,
1100 logit("Warning: Permanently added the %s host "
1101 "key for IP address '%.128s' to the list "
1102 "of known hosts.", type, ip);
1103 } else if (options.visual_host_key) {
1104 fp = sshkey_fingerprint(host_key,
1105 options.fingerprint_hash, SSH_FP_DEFAULT);
1106 ra = sshkey_fingerprint(host_key,
1107 options.fingerprint_hash, SSH_FP_RANDOMART);
1108 if (fp == NULL || ra == NULL)
1109 fatal_f("sshkey_fingerprint failed");
1110 logit("Host key fingerprint is %s\n%s", fp, ra);
1114 hostkey_trusted = 1;
1117 if (options.host_key_alias == NULL && port != 0 &&
1118 port != SSH_DEFAULT_PORT && !clobber_port) {
1119 debug("checking without port identifier");
1120 if (check_host_key(hostname, cinfo, hostaddr, 0,
1121 host_key, ROQUIET, 1,
1122 user_hostfiles, num_user_hostfiles,
1123 system_hostfiles, num_system_hostfiles,
1124 hostfile_command) == 0) {
1125 debug("found matching key w/out port");
1129 if (readonly || want_cert)
1131 /* The host is new. */
1132 if (options.strict_host_key_checking ==
1133 SSH_STRICT_HOSTKEY_YES) {
1135 * User has requested strict host key checking. We
1136 * will not add the host key automatically. The only
1137 * alternative left is to abort.
1139 error("No %s host key is known for %.200s and you "
1140 "have requested strict checking.", type, host);
1142 } else if (options.strict_host_key_checking ==
1143 SSH_STRICT_HOSTKEY_ASK) {
1144 char *msg1 = NULL, *msg2 = NULL;
1146 xasprintf(&msg1, "The authenticity of host "
1147 "'%.200s (%s)' can't be established", host, ip);
1149 if (show_other_keys(host_hostkeys, host_key)) {
1150 xextendf(&msg1, "\n", "but keys of different "
1151 "type are already known for this host.");
1153 xextendf(&msg1, "", ".");
1155 fp = sshkey_fingerprint(host_key,
1156 options.fingerprint_hash, SSH_FP_DEFAULT);
1157 ra = sshkey_fingerprint(host_key,
1158 options.fingerprint_hash, SSH_FP_RANDOMART);
1159 if (fp == NULL || ra == NULL)
1160 fatal_f("sshkey_fingerprint failed");
1161 xextendf(&msg1, "\n", "%s key fingerprint is %s.",
1163 if (options.visual_host_key)
1164 xextendf(&msg1, "\n", "%s", ra);
1165 if (options.verify_host_key_dns) {
1166 xextendf(&msg1, "\n",
1167 "%s host key fingerprint found in DNS.",
1168 matching_host_key_dns ?
1169 "Matching" : "No matching");
1171 /* msg2 informs for other names matching this key */
1172 if ((msg2 = other_hostkeys_message(host, ip, host_key,
1173 user_hostfiles, num_user_hostfiles,
1174 system_hostfiles, num_system_hostfiles)) != NULL)
1175 xextendf(&msg1, "\n", "%s", msg2);
1177 xextendf(&msg1, "\n",
1178 "Are you sure you want to continue connecting "
1179 "(yes/no/[fingerprint])? ");
1181 confirmed = confirm(msg1, fp);
1188 hostkey_trusted = 1; /* user explicitly confirmed */
1191 * If in "new" or "off" strict mode, add the key automatically
1192 * to the local known_hosts file.
1194 if (options.check_host_ip && ip_status == HOST_NEW) {
1195 snprintf(hostline, sizeof(hostline), "%s,%s", host, ip);
1197 if (options.hash_known_hosts) {
1198 /* Add hash of host and IP separately */
1199 r = add_host_to_hostfile(user_hostfiles[0],
1200 host, host_key, options.hash_known_hosts) &&
1201 add_host_to_hostfile(user_hostfiles[0], ip,
1202 host_key, options.hash_known_hosts);
1204 /* Add unhashed "host,ip" */
1205 r = add_host_to_hostfile(user_hostfiles[0],
1207 options.hash_known_hosts);
1210 r = add_host_to_hostfile(user_hostfiles[0], host,
1211 host_key, options.hash_known_hosts);
1216 logit("Failed to add the host to the list of known "
1217 "hosts (%.500s).", user_hostfiles[0]);
1219 logit("Warning: Permanently added '%.200s' (%s) to the "
1220 "list of known hosts.", hostp, type);
1223 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1224 error("@ WARNING: REVOKED HOST KEY DETECTED! @");
1225 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1226 error("The %s host key for %s is marked as revoked.", type, host);
1227 error("This could mean that a stolen key is being used to");
1228 error("impersonate this host.");
1231 * If strict host key checking is in use, the user will have
1232 * to edit the key manually and we can only abort.
1234 if (options.strict_host_key_checking !=
1235 SSH_STRICT_HOSTKEY_OFF) {
1236 error("%s host key for %.200s was revoked and you have "
1237 "requested strict checking.", type, host);
1240 goto continue_unsafe;
1245 * This is only a debug() since it is valid to have
1246 * CAs with wildcard DNS matches that don't match
1247 * all hosts that one might visit.
1249 debug("Host certificate authority does not "
1250 "match %s in %s:%lu", CA_MARKER,
1251 host_found->file, host_found->line);
1254 if (readonly == ROQUIET)
1256 if (options.check_host_ip && host_ip_differ) {
1258 if (ip_status == HOST_NEW)
1259 key_msg = "is unknown";
1260 else if (ip_status == HOST_OK)
1261 key_msg = "is unchanged";
1263 key_msg = "has a different value";
1264 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1265 error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
1266 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1267 error("The %s host key for %s has changed,", type, host);
1268 error("and the key for the corresponding IP address %s", ip);
1269 error("%s. This could either mean that", key_msg);
1270 error("DNS SPOOFING is happening or the IP address for the host");
1271 error("and its host key have changed at the same time.");
1272 if (ip_status != HOST_NEW)
1273 error("Offending key for IP in %s:%lu",
1274 ip_found->file, ip_found->line);
1276 /* The host key has changed. */
1277 warn_changed_key(host_key);
1278 if (num_user_hostfiles > 0 || num_system_hostfiles > 0) {
1279 error("Add correct host key in %.100s to get rid "
1280 "of this message.", num_user_hostfiles > 0 ?
1281 user_hostfiles[0] : system_hostfiles[0]);
1283 error("Offending %s key in %s:%lu",
1284 sshkey_type(host_found->key),
1285 host_found->file, host_found->line);
1288 * If strict host key checking is in use, the user will have
1289 * to edit the key manually and we can only abort.
1291 if (options.strict_host_key_checking !=
1292 SSH_STRICT_HOSTKEY_OFF) {
1293 error("Host key for %.200s has changed and you have "
1294 "requested strict checking.", host);
1300 * If strict host key checking has not been requested, allow
1301 * the connection but without MITM-able authentication or
1304 if (options.password_authentication) {
1305 error("Password authentication is disabled to avoid "
1306 "man-in-the-middle attacks.");
1307 options.password_authentication = 0;
1308 cancelled_forwarding = 1;
1310 if (options.kbd_interactive_authentication) {
1311 error("Keyboard-interactive authentication is disabled"
1312 " to avoid man-in-the-middle attacks.");
1313 options.kbd_interactive_authentication = 0;
1314 cancelled_forwarding = 1;
1316 if (options.forward_agent) {
1317 error("Agent forwarding is disabled to avoid "
1318 "man-in-the-middle attacks.");
1319 options.forward_agent = 0;
1320 cancelled_forwarding = 1;
1322 if (options.forward_x11) {
1323 error("X11 forwarding is disabled to avoid "
1324 "man-in-the-middle attacks.");
1325 options.forward_x11 = 0;
1326 cancelled_forwarding = 1;
1328 if (options.num_local_forwards > 0 ||
1329 options.num_remote_forwards > 0) {
1330 error("Port forwarding is disabled to avoid "
1331 "man-in-the-middle attacks.");
1332 options.num_local_forwards =
1333 options.num_remote_forwards = 0;
1334 cancelled_forwarding = 1;
1336 if (options.tun_open != SSH_TUNMODE_NO) {
1337 error("Tunnel forwarding is disabled to avoid "
1338 "man-in-the-middle attacks.");
1339 options.tun_open = SSH_TUNMODE_NO;
1340 cancelled_forwarding = 1;
1342 if (options.update_hostkeys != 0) {
1343 error("UpdateHostkeys is disabled because the host "
1344 "key is not trusted.");
1345 options.update_hostkeys = 0;
1347 if (options.exit_on_forward_failure && cancelled_forwarding)
1348 fatal("Error: forwarding disabled due to host key "
1352 * XXX Should permit the user to change to use the new id.
1353 * This could be done by converting the host key to an
1354 * identifying sentence, tell that the host identifies itself
1355 * by that sentence, and ask the user if they wish to
1356 * accept the authentication.
1360 fatal("internal error");
1364 if (options.check_host_ip && host_status != HOST_CHANGED &&
1365 ip_status == HOST_CHANGED) {
1366 snprintf(msg, sizeof(msg),
1367 "Warning: the %s host key for '%.200s' "
1368 "differs from the key for the IP address '%.128s'"
1369 "\nOffending key for IP in %s:%lu",
1370 type, host, ip, ip_found->file, ip_found->line);
1371 if (host_status == HOST_OK) {
1373 snprintf(msg + len, sizeof(msg) - len,
1374 "\nMatching host key in %s:%lu",
1375 host_found->file, host_found->line);
1377 if (options.strict_host_key_checking ==
1378 SSH_STRICT_HOSTKEY_ASK) {
1379 strlcat(msg, "\nAre you sure you want "
1380 "to continue connecting (yes/no)? ", sizeof(msg));
1381 if (!confirm(msg, NULL))
1383 } else if (options.strict_host_key_checking !=
1384 SSH_STRICT_HOSTKEY_OFF) {
1386 error("Exiting, you have requested strict checking.");
1393 if (!hostkey_trusted && options.update_hostkeys) {
1394 debug_f("hostkey not known or explicitly trusted: "
1395 "disabling UpdateHostkeys");
1396 options.update_hostkeys = 0;
1401 if (host_hostkeys != NULL)
1402 free_hostkeys(host_hostkeys);
1403 if (ip_hostkeys != NULL)
1404 free_hostkeys(ip_hostkeys);
1408 if (want_cert && host_status != HOST_REVOKED) {
1410 * No matching certificate. Downgrade cert to raw key and
1413 debug("No matching CA found. Retry with plain key");
1414 if ((r = sshkey_from_private(host_key, &raw_key)) != 0)
1415 fatal_fr(r, "decode key");
1416 if ((r = sshkey_drop_cert(raw_key)) != 0)
1417 fatal_r(r, "Couldn't drop certificate");
1421 sshkey_free(raw_key);
1424 if (host_hostkeys != NULL)
1425 free_hostkeys(host_hostkeys);
1426 if (ip_hostkeys != NULL)
1427 free_hostkeys(ip_hostkeys);
1431 /* returns 0 if key verifies or -1 if key does NOT verify */
1433 verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key,
1434 const struct ssh_conn_info *cinfo)
1437 int r = -1, flags = 0;
1438 char valid[64], *fp = NULL, *cafp = NULL;
1439 struct sshkey *plain = NULL;
1441 if ((fp = sshkey_fingerprint(host_key,
1442 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) {
1443 error_fr(r, "fingerprint host key");
1448 if (sshkey_is_cert(host_key)) {
1449 if ((cafp = sshkey_fingerprint(host_key->cert->signature_key,
1450 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) {
1451 error_fr(r, "fingerprint CA key");
1455 sshkey_format_cert_validity(host_key->cert,
1456 valid, sizeof(valid));
1457 debug("Server host certificate: %s %s, serial %llu "
1458 "ID \"%s\" CA %s %s valid %s",
1459 sshkey_ssh_name(host_key), fp,
1460 (unsigned long long)host_key->cert->serial,
1461 host_key->cert->key_id,
1462 sshkey_ssh_name(host_key->cert->signature_key), cafp,
1464 for (i = 0; i < host_key->cert->nprincipals; i++) {
1465 debug2("Server host certificate hostname: %s",
1466 host_key->cert->principals[i]);
1469 debug("Server host key: %s %s", sshkey_ssh_name(host_key), fp);
1472 if (sshkey_equal(previous_host_key, host_key)) {
1473 debug2_f("server host key %s %s matches cached key",
1474 sshkey_type(host_key), fp);
1479 /* Check in RevokedHostKeys file if specified */
1480 if (options.revoked_host_keys != NULL) {
1481 r = sshkey_check_revoked(host_key, options.revoked_host_keys);
1484 break; /* not revoked */
1485 case SSH_ERR_KEY_REVOKED:
1486 error("Host key %s %s revoked by file %s",
1487 sshkey_type(host_key), fp,
1488 options.revoked_host_keys);
1492 error_r(r, "Error checking host key %s %s in "
1493 "revoked keys file %s", sshkey_type(host_key),
1494 fp, options.revoked_host_keys);
1500 if (options.verify_host_key_dns) {
1502 * XXX certs are not yet supported for DNS, so downgrade
1503 * them and try the plain key.
1505 if ((r = sshkey_from_private(host_key, &plain)) != 0)
1507 if (sshkey_is_cert(plain))
1508 sshkey_drop_cert(plain);
1509 if (verify_host_key_dns(host, hostaddr, plain, &flags) == 0) {
1510 if (flags & DNS_VERIFY_FOUND) {
1511 if (options.verify_host_key_dns == 1 &&
1512 flags & DNS_VERIFY_MATCH &&
1513 flags & DNS_VERIFY_SECURE) {
1517 if (flags & DNS_VERIFY_MATCH) {
1518 matching_host_key_dns = 1;
1520 warn_changed_key(plain);
1521 error("Update the SSHFP RR in DNS "
1522 "with the new host key to get rid "
1523 "of this message.");
1528 r = check_host_key(host, cinfo, hostaddr, options.port, host_key,
1529 RDRW, 0, options.user_hostfiles, options.num_user_hostfiles,
1530 options.system_hostfiles, options.num_system_hostfiles,
1531 options.known_hosts_command);
1537 if (r == 0 && host_key != NULL) {
1538 sshkey_free(previous_host_key);
1539 r = sshkey_from_private(host_key, &previous_host_key);
1546 * Starts a dialog with the server, and authenticates the current user on the
1547 * server. This does not need any extra privileges. The basic connection
1548 * to the server must already have been established before this is called.
1549 * If login fails, this function prints an error and never returns.
1550 * This function does not require super-user privileges.
1553 ssh_login(struct ssh *ssh, Sensitive *sensitive, const char *orighost,
1554 struct sockaddr *hostaddr, u_short port, struct passwd *pw, int timeout_ms,
1555 const struct ssh_conn_info *cinfo)
1558 char *server_user, *local_user;
1561 local_user = xstrdup(pw->pw_name);
1562 server_user = options.user ? options.user : local_user;
1564 /* Convert the user-supplied hostname into all lowercase. */
1565 host = xstrdup(orighost);
1568 /* Exchange protocol version identification strings with the server. */
1569 if ((r = kex_exchange_identification(ssh, timeout_ms, NULL)) != 0)
1570 sshpkt_fatal(ssh, r, "banner exchange");
1572 /* Put the connection into non-blocking mode. */
1573 ssh_packet_set_nonblocking(ssh);
1576 /* authenticate user */
1577 debug("Authenticating to %s:%d as '%s'", host, port, server_user);
1578 ssh_kex2(ssh, host, hostaddr, port, cinfo);
1579 ssh_userauth2(ssh, local_user, server_user, host, sensitive);
1584 /* print all known host keys for a given host, but skip keys of given type */
1586 show_other_keys(struct hostkeys *hostkeys, struct sshkey *key)
1598 const struct hostkey_entry *found;
1600 for (i = 0; type[i] != -1; i++) {
1601 if (type[i] == key->type)
1603 if (!lookup_key_in_hostkeys_by_type(hostkeys, type[i],
1606 fp = sshkey_fingerprint(found->key,
1607 options.fingerprint_hash, SSH_FP_DEFAULT);
1608 ra = sshkey_fingerprint(found->key,
1609 options.fingerprint_hash, SSH_FP_RANDOMART);
1610 if (fp == NULL || ra == NULL)
1611 fatal_f("sshkey_fingerprint fail");
1612 logit("WARNING: %s key found for host %s\n"
1614 "%s key fingerprint %s.",
1615 sshkey_type(found->key),
1616 found->host, found->file, found->line,
1617 sshkey_type(found->key), fp);
1618 if (options.visual_host_key)
1628 warn_changed_key(struct sshkey *host_key)
1632 fp = sshkey_fingerprint(host_key, options.fingerprint_hash,
1635 fatal_f("sshkey_fingerprint fail");
1637 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1638 error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1639 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1640 error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1641 error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1642 error("It is also possible that a host key has just been changed.");
1643 error("The fingerprint for the %s key sent by the remote host is\n%s.",
1644 sshkey_type(host_key), fp);
1645 error("Please contact your system administrator.");
1651 * Execute a local command
1654 ssh_local_cmd(const char *args)
1659 void (*osighand)(int);
1661 if (!options.permit_local_command ||
1662 args == NULL || !*args)
1665 if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
1666 shell = _PATH_BSHELL;
1668 osighand = ssh_signal(SIGCHLD, SIG_DFL);
1671 ssh_signal(SIGPIPE, SIG_DFL);
1672 debug3("Executing %s -c \"%s\"", shell, args);
1673 execl(shell, shell, "-c", args, (char *)NULL);
1674 error("Couldn't execute %s -c \"%s\": %s",
1675 shell, args, strerror(errno));
1677 } else if (pid == -1)
1678 fatal("fork failed: %.100s", strerror(errno));
1679 while (waitpid(pid, &status, 0) == -1)
1681 fatal("Couldn't wait for child: %s", strerror(errno));
1682 ssh_signal(SIGCHLD, osighand);
1684 if (!WIFEXITED(status))
1687 return (WEXITSTATUS(status));
1691 maybe_add_key_to_agent(const char *authfile, struct sshkey *private,
1692 const char *comment, const char *passphrase)
1694 int auth_sock = -1, r;
1695 const char *skprovider = NULL;
1697 if (options.add_keys_to_agent == 0)
1700 if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) {
1701 debug3("no authentication agent, not adding key");
1705 if (options.add_keys_to_agent == 2 &&
1706 !ask_permission("Add key %s (%s) to agent?", authfile, comment)) {
1707 debug3("user denied adding this key");
1711 if (sshkey_is_sk(private))
1712 skprovider = options.sk_provider;
1713 if ((r = ssh_add_identity_constrained(auth_sock, private,
1714 comment == NULL ? authfile : comment,
1715 options.add_keys_to_agent_lifespan,
1716 (options.add_keys_to_agent == 3), 0, skprovider, NULL, 0)) == 0)
1717 debug("identity added to agent: %s", authfile);
1719 debug("could not add identity to agent: %s (%d)", authfile, r);