1 /* $OpenBSD: sshconnect.c,v 1.361 2023/01/13 02:44:02 djm 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>
59 #include "sshconnect.h"
65 #include "monitor_fdpass.h"
73 struct sshkey *previous_host_key = NULL;
75 static int matching_host_key_dns = 0;
77 static pid_t proxy_command_pid = 0;
80 extern int debug_flag;
81 extern Options options;
82 extern char *__progname;
84 static int show_other_keys(struct hostkeys *, struct sshkey *);
85 static void warn_changed_key(struct sshkey *);
87 /* Expand a proxy command */
89 expand_proxy_command(const char *proxy_command, const char *user,
90 const char *host, const char *host_arg, int port)
92 char *tmp, *ret, strport[NI_MAXSERV];
93 const char *keyalias = options.host_key_alias ?
94 options.host_key_alias : host_arg;
96 snprintf(strport, sizeof strport, "%d", port);
97 xasprintf(&tmp, "exec %s", proxy_command);
98 ret = percent_expand(tmp,
110 * Connect to the given ssh server using a proxy command that passes a
111 * a connected fd back to us.
114 ssh_proxy_fdpass_connect(struct ssh *ssh, const char *host,
115 const char *host_arg, u_short port, const char *proxy_command)
117 char *command_string;
122 if ((shell = getenv("SHELL")) == NULL)
123 shell = _PATH_BSHELL;
125 if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) == -1)
126 fatal("Could not create socketpair to communicate with "
127 "proxy dialer: %.100s", strerror(errno));
129 command_string = expand_proxy_command(proxy_command, options.user,
130 host, host_arg, port);
131 debug("Executing proxy dialer command: %.500s", command_string);
133 /* Fork and execute the proxy command. */
134 if ((pid = fork()) == 0) {
138 /* Redirect stdin and stdout. */
140 if (dup2(sp[0], 0) == -1)
141 perror("dup2 stdin");
144 if (dup2(sp[0], 1) == -1)
145 perror("dup2 stdout");
151 * Stderr is left for non-ControlPersist connections is so
152 * error messages may be printed on the user's terminal.
154 if (!debug_flag && options.control_path != NULL &&
155 options.control_persist && stdfd_devnull(0, 0, 1) == -1)
156 error_f("stdfd_devnull failed");
160 argv[2] = command_string;
164 * Execute the proxy command.
165 * Note that we gave up any extra privileges above.
167 execv(argv[0], argv);
173 fatal("fork failed: %.100s", strerror(errno));
175 free(command_string);
177 if ((sock = mm_receive_fd(sp[1])) == -1)
178 fatal("proxy dialer did not pass back a connection");
181 while (waitpid(pid, NULL, 0) == -1)
183 fatal("Couldn't wait for child: %s", strerror(errno));
185 /* Set the connection file descriptors. */
186 if (ssh_packet_set_connection(ssh, sock, sock) == NULL)
187 return -1; /* ssh_packet_set_connection logs error */
193 * Connect to the given ssh server using a proxy command.
196 ssh_proxy_connect(struct ssh *ssh, const char *host, const char *host_arg,
197 u_short port, const char *proxy_command)
199 char *command_string;
204 if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
205 shell = _PATH_BSHELL;
207 /* Create pipes for communicating with the proxy. */
208 if (pipe(pin) == -1 || pipe(pout) == -1)
209 fatal("Could not create pipes to communicate with the proxy: %.100s",
212 command_string = expand_proxy_command(proxy_command, options.user,
213 host, host_arg, port);
214 debug("Executing proxy command: %.500s", command_string);
216 /* Fork and execute the proxy command. */
217 if ((pid = fork()) == 0) {
220 /* Redirect stdin and stdout. */
223 if (dup2(pin[0], 0) == -1)
224 perror("dup2 stdin");
228 if (dup2(pout[1], 1) == -1)
229 perror("dup2 stdout");
230 /* Cannot be 1 because pin allocated two descriptors. */
234 * Stderr is left for non-ControlPersist connections is so
235 * error messages may be printed on the user's terminal.
237 if (!debug_flag && options.control_path != NULL &&
238 options.control_persist && stdfd_devnull(0, 0, 1) == -1)
239 error_f("stdfd_devnull failed");
243 argv[2] = command_string;
247 * Execute the proxy command. Note that we gave up any
248 * extra privileges above.
250 ssh_signal(SIGPIPE, SIG_DFL);
251 execv(argv[0], argv);
257 fatal("fork failed: %.100s", strerror(errno));
259 proxy_command_pid = pid; /* save pid to clean up later */
261 /* Close child side of the descriptors. */
265 /* Free the command name. */
266 free(command_string);
268 /* Set the connection file descriptors. */
269 if (ssh_packet_set_connection(ssh, pout[0], pin[1]) == NULL)
270 return -1; /* ssh_packet_set_connection logs error */
276 ssh_kill_proxy_command(void)
279 * Send SIGHUP to proxy command if used. We don't wait() in
280 * case it hangs and instead rely on init to reap the child
282 if (proxy_command_pid > 1)
283 kill(proxy_command_pid, SIGHUP);
286 #ifdef HAVE_IFADDRS_H
288 * Search a interface address list (returned from getifaddrs(3)) for an
289 * address that matches the desired address family on the specified interface.
290 * Returns 0 and fills in *resultp and *rlenp on success. Returns -1 on failure.
293 check_ifaddrs(const char *ifname, int af, const struct ifaddrs *ifaddrs,
294 struct sockaddr_storage *resultp, socklen_t *rlenp)
296 struct sockaddr_in6 *sa6;
297 struct sockaddr_in *sa;
298 struct in6_addr *v6addr;
299 const struct ifaddrs *ifa;
303 * Prefer addresses that are not loopback or linklocal, but use them
304 * if nothing else matches.
306 for (allow_local = 0; allow_local < 2; allow_local++) {
307 for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
308 if (ifa->ifa_addr == NULL || ifa->ifa_name == NULL ||
309 (ifa->ifa_flags & IFF_UP) == 0 ||
310 ifa->ifa_addr->sa_family != af ||
311 strcmp(ifa->ifa_name, options.bind_interface) != 0)
313 switch (ifa->ifa_addr->sa_family) {
315 sa = (struct sockaddr_in *)ifa->ifa_addr;
316 if (!allow_local && sa->sin_addr.s_addr ==
317 htonl(INADDR_LOOPBACK))
319 if (*rlenp < sizeof(struct sockaddr_in)) {
320 error_f("v4 addr doesn't fit");
323 *rlenp = sizeof(struct sockaddr_in);
324 memcpy(resultp, sa, *rlenp);
327 sa6 = (struct sockaddr_in6 *)ifa->ifa_addr;
328 v6addr = &sa6->sin6_addr;
330 (IN6_IS_ADDR_LINKLOCAL(v6addr) ||
331 IN6_IS_ADDR_LOOPBACK(v6addr)))
333 if (*rlenp < sizeof(struct sockaddr_in6)) {
334 error_f("v6 addr doesn't fit");
337 *rlenp = sizeof(struct sockaddr_in6);
338 memcpy(resultp, sa6, *rlenp);
348 * Creates a socket for use as the ssh connection.
351 ssh_create_socket(struct addrinfo *ai)
354 struct sockaddr_storage bindaddr;
355 socklen_t bindaddrlen = 0;
356 struct addrinfo hints, *res = NULL;
357 #ifdef HAVE_IFADDRS_H
358 struct ifaddrs *ifaddrs = NULL;
360 char ntop[NI_MAXHOST];
362 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
364 error("socket: %s", strerror(errno));
367 fcntl(sock, F_SETFD, FD_CLOEXEC);
369 /* Use interactive QOS (if specified) until authentication completed */
370 if (options.ip_qos_interactive != INT_MAX)
371 set_sock_tos(sock, options.ip_qos_interactive);
373 /* Bind the socket to an alternative local IP address */
374 if (options.bind_address == NULL && options.bind_interface == NULL)
377 if (options.bind_address != NULL) {
378 memset(&hints, 0, sizeof(hints));
379 hints.ai_family = ai->ai_family;
380 hints.ai_socktype = ai->ai_socktype;
381 hints.ai_protocol = ai->ai_protocol;
382 hints.ai_flags = AI_PASSIVE;
383 if ((r = getaddrinfo(options.bind_address, NULL,
384 &hints, &res)) != 0) {
385 error("getaddrinfo: %s: %s", options.bind_address,
386 ssh_gai_strerror(r));
390 error("getaddrinfo: no addrs");
393 memcpy(&bindaddr, res->ai_addr, res->ai_addrlen);
394 bindaddrlen = res->ai_addrlen;
395 } else if (options.bind_interface != NULL) {
396 #ifdef HAVE_IFADDRS_H
397 if ((r = getifaddrs(&ifaddrs)) != 0) {
398 error("getifaddrs: %s: %s", options.bind_interface,
402 bindaddrlen = sizeof(bindaddr);
403 if (check_ifaddrs(options.bind_interface, ai->ai_family,
404 ifaddrs, &bindaddr, &bindaddrlen) != 0) {
405 logit("getifaddrs: %s: no suitable addresses",
406 options.bind_interface);
410 error("BindInterface not supported on this platform.");
413 if ((r = getnameinfo((struct sockaddr *)&bindaddr, bindaddrlen,
414 ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST)) != 0) {
415 error_f("getnameinfo failed: %s", ssh_gai_strerror(r));
418 if (bind(sock, (struct sockaddr *)&bindaddr, bindaddrlen) != 0) {
419 error("bind %s: %s", ntop, strerror(errno));
422 debug_f("bound to %s", ntop);
431 #ifdef HAVE_IFADDRS_H
433 freeifaddrs(ifaddrs);
439 * Opens a TCP/IP connection to the remote server on the given host.
440 * The address of the remote host will be returned in hostaddr.
441 * If port is 0, the default port will be used.
442 * Connection_attempts specifies the maximum number of tries (one per
443 * second). If proxy_command is non-NULL, it specifies the command (with %h
444 * and %p substituted for host and port, respectively) to use to contact
448 ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
449 struct sockaddr_storage *hostaddr, u_short port, int connection_attempts,
450 int *timeout_ms, int want_keepalive)
452 int on = 1, saved_timeout_ms = *timeout_ms;
453 int oerrno, sock = -1, attempt;
454 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
457 debug3_f("entering");
458 memset(ntop, 0, sizeof(ntop));
459 memset(strport, 0, sizeof(strport));
461 for (attempt = 0; attempt < connection_attempts; attempt++) {
463 /* Sleep a moment before retrying. */
465 debug("Trying again...");
468 * Loop through addresses for this host, and try each one in
469 * sequence until the connection succeeds.
471 for (ai = aitop; ai; ai = ai->ai_next) {
472 if (ai->ai_family != AF_INET &&
473 ai->ai_family != AF_INET6) {
474 errno = EAFNOSUPPORT;
477 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
478 ntop, sizeof(ntop), strport, sizeof(strport),
479 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
481 error_f("getnameinfo failed");
485 debug("Connecting to %.200s [%.100s] port %s.",
486 host, ntop, strport);
488 /* Create a socket for connecting. */
489 sock = ssh_create_socket(ai);
491 /* Any error is already output */
496 *timeout_ms = saved_timeout_ms;
497 if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
499 /* Successful connection. */
500 memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
504 debug("connect to address %s port %s: %s",
505 ntop, strport, strerror(errno));
512 break; /* Successful connection. */
515 /* Return failure if we didn't get a successful connection. */
517 error("ssh: connect to host %s port %s: %s",
518 host, strport, errno == 0 ? "failure" : strerror(errno));
522 debug("Connection established.");
524 /* Set SO_KEEPALIVE if requested. */
525 if (want_keepalive &&
526 setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
528 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
530 /* Set the connection. */
531 if (ssh_packet_set_connection(ssh, sock, sock) == NULL)
532 return -1; /* ssh_packet_set_connection logs error */
538 ssh_connect(struct ssh *ssh, const char *host, const char *host_arg,
539 struct addrinfo *addrs, struct sockaddr_storage *hostaddr, u_short port,
540 int connection_attempts, int *timeout_ms, int want_keepalive)
544 if (options.proxy_command == NULL) {
545 return ssh_connect_direct(ssh, host, addrs, hostaddr, port,
546 connection_attempts, timeout_ms, want_keepalive);
547 } else if (strcmp(options.proxy_command, "-") == 0) {
548 if ((in = dup(STDIN_FILENO)) == -1 ||
549 (out = dup(STDOUT_FILENO)) == -1) {
552 error_f("dup() in/out failed");
553 return -1; /* ssh_packet_set_connection logs error */
555 if ((ssh_packet_set_connection(ssh, in, out)) == NULL)
556 return -1; /* ssh_packet_set_connection logs error */
558 } else if (options.proxy_use_fdpass) {
559 return ssh_proxy_fdpass_connect(ssh, host, host_arg, port,
560 options.proxy_command);
562 return ssh_proxy_connect(ssh, host, host_arg, port,
563 options.proxy_command);
566 /* defaults to 'no' */
568 confirm(const char *prompt, const char *fingerprint)
570 const char *msg, *again = "Please type 'yes' or 'no': ";
571 const char *again_fp = "Please type 'yes', 'no' or the fingerprint: ";
575 if (options.batch_mode)
577 for (msg = prompt;;msg = fingerprint ? again_fp : again) {
578 cp = p = read_passphrase(msg, RP_ECHO);
581 p += strspn(p, " \t"); /* skip leading whitespace */
582 p[strcspn(p, " \t\n")] = '\0'; /* remove trailing whitespace */
583 if (p[0] == '\0' || strcasecmp(p, "no") == 0)
585 else if (strcasecmp(p, "yes") == 0 || (fingerprint != NULL &&
586 strcmp(p, fingerprint) == 0))
595 sockaddr_is_local(struct sockaddr *hostaddr)
597 switch (hostaddr->sa_family) {
599 return (ntohl(((struct sockaddr_in *)hostaddr)->
600 sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
602 return IN6_IS_ADDR_LOOPBACK(
603 &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
610 * Prepare the hostname and ip address strings that are used to lookup
611 * host keys in known_hosts files. These may have a port number appended.
614 get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr,
615 u_short port, char **hostfile_hostname, char **hostfile_ipaddr)
617 char ntop[NI_MAXHOST];
620 switch (hostaddr == NULL ? -1 : hostaddr->sa_family) {
625 addrlen = sizeof(struct sockaddr_in);
628 addrlen = sizeof(struct sockaddr_in6);
631 addrlen = sizeof(struct sockaddr);
636 * We don't have the remote ip-address for connections
637 * using a proxy command
639 if (hostfile_ipaddr != NULL) {
640 if (options.proxy_command == NULL) {
641 if (getnameinfo(hostaddr, addrlen,
642 ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST) != 0)
643 fatal_f("getnameinfo failed");
644 *hostfile_ipaddr = put_host_port(ntop, port);
646 *hostfile_ipaddr = xstrdup("<no hostip for proxy "
652 * Allow the user to record the key under a different name or
653 * differentiate a non-standard port. This is useful for ssh
654 * tunneling over forwarded connections or if you run multiple
655 * sshd's on different ports on the same machine.
657 if (hostfile_hostname != NULL) {
658 if (options.host_key_alias != NULL) {
659 *hostfile_hostname = xstrdup(options.host_key_alias);
660 debug("using hostkeyalias: %s", *hostfile_hostname);
662 *hostfile_hostname = put_host_port(hostname, port);
667 /* returns non-zero if path appears in hostfiles, or 0 if not. */
669 path_in_hostfiles(const char *path, char **hostfiles, u_int num_hostfiles)
673 for (i = 0; i < num_hostfiles; i++) {
674 if (strcmp(path, hostfiles[i]) == 0)
680 struct find_by_key_ctx {
681 const char *host, *ip;
682 const struct sshkey *key;
687 /* Try to replace home directory prefix (per $HOME) with a ~/ sequence */
689 try_tilde_unexpand(const char *path)
691 char *home, *ret = NULL;
695 return xstrdup(path);
696 if ((home = getenv("HOME")) == NULL || (l = strlen(home)) == 0)
697 return xstrdup(path);
698 if (strncmp(path, home, l) != 0)
699 return xstrdup(path);
701 * ensure we have matched on a path boundary: either the $HOME that
702 * we just compared ends with a '/' or the next character of the path
705 if (home[l - 1] != '/' && path[l] != '/')
706 return xstrdup(path);
709 xasprintf(&ret, "~/%s", path + l);
714 hostkeys_find_by_key_cb(struct hostkey_foreach_line *l, void *_ctx)
716 struct find_by_key_ctx *ctx = (struct find_by_key_ctx *)_ctx;
719 /* we are looking for keys with names that *do not* match */
720 if ((l->match & HKF_MATCH_HOST) != 0)
722 /* not interested in marker lines */
723 if (l->marker != MRK_NONE)
725 /* we are only interested in exact key matches */
726 if (l->key == NULL || !sshkey_equal(ctx->key, l->key))
728 path = try_tilde_unexpand(l->path);
729 debug_f("found matching key in %s:%lu", path, l->linenum);
730 ctx->names = xrecallocarray(ctx->names,
731 ctx->nnames, ctx->nnames + 1, sizeof(*ctx->names));
732 xasprintf(&ctx->names[ctx->nnames], "%s:%lu: %s", path, l->linenum,
733 strncmp(l->hosts, HASH_MAGIC, strlen(HASH_MAGIC)) == 0 ?
734 "[hashed name]" : l->hosts);
741 hostkeys_find_by_key_hostfile(const char *file, const char *which,
742 struct find_by_key_ctx *ctx)
746 debug3_f("trying %s hostfile \"%s\"", which, file);
747 if ((r = hostkeys_foreach(file, hostkeys_find_by_key_cb, ctx,
748 ctx->host, ctx->ip, HKF_WANT_PARSE_KEY, 0)) != 0) {
749 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
750 debug_f("hostkeys file %s does not exist", file);
753 error_fr(r, "hostkeys_foreach failed for %s", file);
760 * Find 'key' in known hosts file(s) that do not match host/ip.
761 * Used to display also-known-as information for previously-unseen hostkeys.
764 hostkeys_find_by_key(const char *host, const char *ip, const struct sshkey *key,
765 char **user_hostfiles, u_int num_user_hostfiles,
766 char **system_hostfiles, u_int num_system_hostfiles,
767 char ***names, u_int *nnames)
769 struct find_by_key_ctx ctx = {0, 0, 0, 0, 0};
775 if (key == NULL || sshkey_is_cert(key))
782 for (i = 0; i < num_user_hostfiles; i++) {
783 if (hostkeys_find_by_key_hostfile(user_hostfiles[i],
787 for (i = 0; i < num_system_hostfiles; i++) {
788 if (hostkeys_find_by_key_hostfile(system_hostfiles[i],
789 "system", &ctx) != 0)
794 *nnames = ctx.nnames;
799 for (i = 0; i < ctx.nnames; i++)
804 #define MAX_OTHER_NAMES 8 /* Maximum number of names to list */
806 other_hostkeys_message(const char *host, const char *ip,
807 const struct sshkey *key,
808 char **user_hostfiles, u_int num_user_hostfiles,
809 char **system_hostfiles, u_int num_system_hostfiles)
811 char *ret = NULL, **othernames = NULL;
812 u_int i, n, num_othernames = 0;
814 hostkeys_find_by_key(host, ip, key,
815 user_hostfiles, num_user_hostfiles,
816 system_hostfiles, num_system_hostfiles,
817 &othernames, &num_othernames);
818 if (num_othernames == 0)
819 return xstrdup("This key is not known by any other names.");
821 xasprintf(&ret, "This host key is known by the following other "
825 if (n > MAX_OTHER_NAMES)
827 for (i = 0; i < n; i++) {
828 xextendf(&ret, "\n", " %s", othernames[i]);
830 if (n < num_othernames) {
831 xextendf(&ret, "\n", " (%d additional names omitted)",
834 for (i = 0; i < num_othernames; i++)
841 load_hostkeys_command(struct hostkeys *hostkeys, const char *command_template,
842 const char *invocation, const struct ssh_conn_info *cinfo,
843 const struct sshkey *host_key, const char *hostfile_hostname)
846 char *key_fp = NULL, *keytext = NULL, *tmp;
847 char *command = NULL, *tag = NULL, **av = NULL;
850 void (*osigchld)(int);
852 xasprintf(&tag, "KnownHostsCommand-%s", invocation);
854 if (host_key != NULL) {
855 if ((key_fp = sshkey_fingerprint(host_key,
856 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
857 fatal_f("sshkey_fingerprint failed");
858 if ((r = sshkey_to_base64(host_key, &keytext)) != 0)
859 fatal_fr(r, "sshkey_to_base64 failed");
862 * NB. all returns later this function should go via "out" to
863 * ensure the original SIGCHLD handler is restored properly.
865 osigchld = ssh_signal(SIGCHLD, SIG_DFL);
867 /* Turn the command into an argument vector */
868 if (argv_split(command_template, &ac, &av, 0) != 0) {
869 error("%s \"%s\" contains invalid quotes", tag,
874 error("%s \"%s\" yielded no arguments", tag,
878 for (i = 1; i < ac; i++) {
879 tmp = percent_dollar_expand(av[i],
880 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
881 "H", hostfile_hostname,
883 "t", host_key == NULL ? "NONE" : sshkey_ssh_name(host_key),
884 "f", key_fp == NULL ? "NONE" : key_fp,
885 "K", keytext == NULL ? "NONE" : keytext,
888 fatal_f("percent_expand failed");
892 /* Prepare a printable command for logs, etc. */
893 command = argv_assemble(ac, av);
895 if ((pid = subprocess(tag, command, ac, av, &f,
896 SSH_SUBPROCESS_STDOUT_CAPTURE|SSH_SUBPROCESS_UNSAFE_PATH|
897 SSH_SUBPROCESS_PRESERVE_ENV, NULL, NULL, NULL)) == 0)
900 load_hostkeys_file(hostkeys, hostfile_hostname, tag, f, 1);
902 if (exited_cleanly(pid, tag, command, 0) != 0)
903 fatal("KnownHostsCommand failed");
908 ssh_signal(SIGCHLD, osigchld);
909 for (i = 0; i < ac; i++)
919 * check whether the supplied host key is valid, return -1 if the key
920 * is not valid. user_hostfile[0] will not be updated if 'readonly' is true.
926 check_host_key(char *hostname, const struct ssh_conn_info *cinfo,
927 struct sockaddr *hostaddr, u_short port,
928 struct sshkey *host_key, int readonly, int clobber_port,
929 char **user_hostfiles, u_int num_user_hostfiles,
930 char **system_hostfiles, u_int num_system_hostfiles,
931 const char *hostfile_command)
933 HostStatus host_status = -1, ip_status = -1;
934 struct sshkey *raw_key = NULL;
935 char *ip = NULL, *host = NULL;
936 char hostline[1000], *hostp, *fp, *ra;
938 const char *type, *fail_reason = NULL;
939 const struct hostkey_entry *host_found = NULL, *ip_found = NULL;
940 int len, cancelled_forwarding = 0, confirmed;
941 int local = sockaddr_is_local(hostaddr);
942 int r, want_cert = sshkey_is_cert(host_key), host_ip_differ = 0;
943 int hostkey_trusted = 0; /* Known or explicitly accepted by user */
944 struct hostkeys *host_hostkeys, *ip_hostkeys;
948 * Force accepting of the host key for loopback/localhost. The
949 * problem is that if the home directory is NFS-mounted to multiple
950 * machines, localhost will refer to a different machine in each of
951 * them, and the user will get bogus HOST_CHANGED warnings. This
952 * essentially disables host authentication for localhost; however,
953 * this is probably not a real problem.
955 if (options.no_host_authentication_for_localhost == 1 && local &&
956 options.host_key_alias == NULL) {
957 debug("Forcing accepting of host key for "
958 "loopback/localhost.");
959 options.update_hostkeys = 0;
964 * Don't ever try to write an invalid name to a known hosts file.
965 * Note: do this before get_hostfile_hostname_ipaddr() to catch
966 * '[' or ']' in the name before they are added.
968 if (strcspn(hostname, "@?*#[]|'\'\"\\") != strlen(hostname)) {
969 debug_f("invalid hostname \"%s\"; will not record: %s",
970 hostname, fail_reason);
975 * Prepare the hostname and address strings used for hostkey lookup.
976 * In some cases, these will have a port number appended.
978 get_hostfile_hostname_ipaddr(hostname, hostaddr,
979 clobber_port ? 0 : port, &host, &ip);
982 * Turn off check_host_ip if the connection is to localhost, via proxy
983 * command or if we don't have a hostname to compare with
985 if (options.check_host_ip && (local ||
986 strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
987 options.check_host_ip = 0;
989 host_hostkeys = init_hostkeys();
990 for (i = 0; i < num_user_hostfiles; i++)
991 load_hostkeys(host_hostkeys, host, user_hostfiles[i], 0);
992 for (i = 0; i < num_system_hostfiles; i++)
993 load_hostkeys(host_hostkeys, host, system_hostfiles[i], 0);
994 if (hostfile_command != NULL && !clobber_port) {
995 load_hostkeys_command(host_hostkeys, hostfile_command,
996 "HOSTNAME", cinfo, host_key, host);
1000 if (!want_cert && options.check_host_ip) {
1001 ip_hostkeys = init_hostkeys();
1002 for (i = 0; i < num_user_hostfiles; i++)
1003 load_hostkeys(ip_hostkeys, ip, user_hostfiles[i], 0);
1004 for (i = 0; i < num_system_hostfiles; i++)
1005 load_hostkeys(ip_hostkeys, ip, system_hostfiles[i], 0);
1006 if (hostfile_command != NULL && !clobber_port) {
1007 load_hostkeys_command(ip_hostkeys, hostfile_command,
1008 "ADDRESS", cinfo, host_key, ip);
1013 /* Reload these as they may have changed on cert->key downgrade */
1014 want_cert = sshkey_is_cert(host_key);
1015 type = sshkey_type(host_key);
1018 * Check if the host key is present in the user's list of known
1019 * hosts or in the systemwide list.
1021 host_status = check_key_in_hostkeys(host_hostkeys, host_key,
1025 * If there are no hostfiles, or if the hostkey was found via
1026 * KnownHostsCommand, then don't try to touch the disk.
1028 if (!readonly && (num_user_hostfiles == 0 ||
1029 (host_found != NULL && host_found->note != 0)))
1033 * Also perform check for the ip address, skip the check if we are
1034 * localhost, looking for a certificate, or the hostname was an ip
1035 * address to begin with.
1037 if (!want_cert && ip_hostkeys != NULL) {
1038 ip_status = check_key_in_hostkeys(ip_hostkeys, host_key,
1040 if (host_status == HOST_CHANGED &&
1041 (ip_status != HOST_CHANGED ||
1042 (ip_found != NULL &&
1043 !sshkey_equal(ip_found->key, host_found->key))))
1046 ip_status = host_status;
1048 switch (host_status) {
1050 /* The host is known and the key matches. */
1051 debug("Host '%.200s' is known and matches the %s host %s.",
1052 host, type, want_cert ? "certificate" : "key");
1053 debug("Found %s in %s:%lu", want_cert ? "CA key" : "key",
1054 host_found->file, host_found->line);
1056 if (sshkey_cert_check_host(host_key,
1057 options.host_key_alias == NULL ?
1058 hostname : options.host_key_alias, 0,
1059 options.ca_sign_algorithms, &fail_reason) != 0) {
1060 error("%s", fail_reason);
1064 * Do not attempt hostkey update if a certificate was
1065 * successfully matched.
1067 if (options.update_hostkeys != 0) {
1068 options.update_hostkeys = 0;
1069 debug3_f("certificate host key in use; "
1070 "disabling UpdateHostkeys");
1073 /* Turn off UpdateHostkeys if key was in system known_hosts */
1074 if (options.update_hostkeys != 0 &&
1075 (path_in_hostfiles(host_found->file,
1076 system_hostfiles, num_system_hostfiles) ||
1077 (ip_status == HOST_OK && ip_found != NULL &&
1078 path_in_hostfiles(ip_found->file,
1079 system_hostfiles, num_system_hostfiles)))) {
1080 options.update_hostkeys = 0;
1081 debug3_f("host key found in GlobalKnownHostsFile; "
1082 "disabling UpdateHostkeys");
1084 if (options.update_hostkeys != 0 && host_found->note) {
1085 options.update_hostkeys = 0;
1086 debug3_f("host key found via KnownHostsCommand; "
1087 "disabling UpdateHostkeys");
1089 if (options.check_host_ip && ip_status == HOST_NEW) {
1090 if (readonly || want_cert)
1091 logit("%s host key for IP address "
1092 "'%.128s' not in list of known hosts.",
1094 else if (!add_host_to_hostfile(user_hostfiles[0], ip,
1095 host_key, options.hash_known_hosts))
1096 logit("Failed to add the %s host key for IP "
1097 "address '%.128s' to the list of known "
1098 "hosts (%.500s).", type, ip,
1101 logit("Warning: Permanently added the %s host "
1102 "key for IP address '%.128s' to the list "
1103 "of known hosts.", type, ip);
1104 } else if (options.visual_host_key) {
1105 fp = sshkey_fingerprint(host_key,
1106 options.fingerprint_hash, SSH_FP_DEFAULT);
1107 ra = sshkey_fingerprint(host_key,
1108 options.fingerprint_hash, SSH_FP_RANDOMART);
1109 if (fp == NULL || ra == NULL)
1110 fatal_f("sshkey_fingerprint failed");
1111 logit("Host key fingerprint is %s\n%s", fp, ra);
1115 hostkey_trusted = 1;
1118 if (options.host_key_alias == NULL && port != 0 &&
1119 port != SSH_DEFAULT_PORT && !clobber_port) {
1120 debug("checking without port identifier");
1121 if (check_host_key(hostname, cinfo, hostaddr, 0,
1122 host_key, ROQUIET, 1,
1123 user_hostfiles, num_user_hostfiles,
1124 system_hostfiles, num_system_hostfiles,
1125 hostfile_command) == 0) {
1126 debug("found matching key w/out port");
1130 if (readonly || want_cert)
1132 /* The host is new. */
1133 if (options.strict_host_key_checking ==
1134 SSH_STRICT_HOSTKEY_YES) {
1136 * User has requested strict host key checking. We
1137 * will not add the host key automatically. The only
1138 * alternative left is to abort.
1140 error("No %s host key is known for %.200s and you "
1141 "have requested strict checking.", type, host);
1143 } else if (options.strict_host_key_checking ==
1144 SSH_STRICT_HOSTKEY_ASK) {
1145 char *msg1 = NULL, *msg2 = NULL;
1147 xasprintf(&msg1, "The authenticity of host "
1148 "'%.200s (%s)' can't be established", host, ip);
1150 if (show_other_keys(host_hostkeys, host_key)) {
1151 xextendf(&msg1, "\n", "but keys of different "
1152 "type are already known for this host.");
1154 xextendf(&msg1, "", ".");
1156 fp = sshkey_fingerprint(host_key,
1157 options.fingerprint_hash, SSH_FP_DEFAULT);
1158 ra = sshkey_fingerprint(host_key,
1159 options.fingerprint_hash, SSH_FP_RANDOMART);
1160 if (fp == NULL || ra == NULL)
1161 fatal_f("sshkey_fingerprint failed");
1162 xextendf(&msg1, "\n", "%s key fingerprint is %s.",
1164 if (options.visual_host_key)
1165 xextendf(&msg1, "\n", "%s", ra);
1166 if (options.verify_host_key_dns) {
1167 xextendf(&msg1, "\n",
1168 "%s host key fingerprint found in DNS.",
1169 matching_host_key_dns ?
1170 "Matching" : "No matching");
1172 /* msg2 informs for other names matching this key */
1173 if ((msg2 = other_hostkeys_message(host, ip, host_key,
1174 user_hostfiles, num_user_hostfiles,
1175 system_hostfiles, num_system_hostfiles)) != NULL)
1176 xextendf(&msg1, "\n", "%s", msg2);
1178 xextendf(&msg1, "\n",
1179 "Are you sure you want to continue connecting "
1180 "(yes/no/[fingerprint])? ");
1182 confirmed = confirm(msg1, fp);
1189 hostkey_trusted = 1; /* user explicitly confirmed */
1192 * If in "new" or "off" strict mode, add the key automatically
1193 * to the local known_hosts file.
1195 if (options.check_host_ip && ip_status == HOST_NEW) {
1196 snprintf(hostline, sizeof(hostline), "%s,%s", host, ip);
1198 if (options.hash_known_hosts) {
1199 /* Add hash of host and IP separately */
1200 r = add_host_to_hostfile(user_hostfiles[0],
1201 host, host_key, options.hash_known_hosts) &&
1202 add_host_to_hostfile(user_hostfiles[0], ip,
1203 host_key, options.hash_known_hosts);
1205 /* Add unhashed "host,ip" */
1206 r = add_host_to_hostfile(user_hostfiles[0],
1208 options.hash_known_hosts);
1211 r = add_host_to_hostfile(user_hostfiles[0], host,
1212 host_key, options.hash_known_hosts);
1217 logit("Failed to add the host to the list of known "
1218 "hosts (%.500s).", user_hostfiles[0]);
1220 logit("Warning: Permanently added '%.200s' (%s) to the "
1221 "list of known hosts.", hostp, type);
1224 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1225 error("@ WARNING: REVOKED HOST KEY DETECTED! @");
1226 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1227 error("The %s host key for %s is marked as revoked.", type, host);
1228 error("This could mean that a stolen key is being used to");
1229 error("impersonate this host.");
1232 * If strict host key checking is in use, the user will have
1233 * to edit the key manually and we can only abort.
1235 if (options.strict_host_key_checking !=
1236 SSH_STRICT_HOSTKEY_OFF) {
1237 error("%s host key for %.200s was revoked and you have "
1238 "requested strict checking.", type, host);
1241 goto continue_unsafe;
1246 * This is only a debug() since it is valid to have
1247 * CAs with wildcard DNS matches that don't match
1248 * all hosts that one might visit.
1250 debug("Host certificate authority does not "
1251 "match %s in %s:%lu", CA_MARKER,
1252 host_found->file, host_found->line);
1255 if (readonly == ROQUIET)
1257 if (options.check_host_ip && host_ip_differ) {
1259 if (ip_status == HOST_NEW)
1260 key_msg = "is unknown";
1261 else if (ip_status == HOST_OK)
1262 key_msg = "is unchanged";
1264 key_msg = "has a different value";
1265 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1266 error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
1267 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1268 error("The %s host key for %s has changed,", type, host);
1269 error("and the key for the corresponding IP address %s", ip);
1270 error("%s. This could either mean that", key_msg);
1271 error("DNS SPOOFING is happening or the IP address for the host");
1272 error("and its host key have changed at the same time.");
1273 if (ip_status != HOST_NEW)
1274 error("Offending key for IP in %s:%lu",
1275 ip_found->file, ip_found->line);
1277 /* The host key has changed. */
1278 warn_changed_key(host_key);
1279 if (num_user_hostfiles > 0 || num_system_hostfiles > 0) {
1280 error("Add correct host key in %.100s to get rid "
1281 "of this message.", num_user_hostfiles > 0 ?
1282 user_hostfiles[0] : system_hostfiles[0]);
1284 error("Offending %s key in %s:%lu",
1285 sshkey_type(host_found->key),
1286 host_found->file, host_found->line);
1289 * If strict host key checking is in use, the user will have
1290 * to edit the key manually and we can only abort.
1292 if (options.strict_host_key_checking !=
1293 SSH_STRICT_HOSTKEY_OFF) {
1294 error("Host key for %.200s has changed and you have "
1295 "requested strict checking.", host);
1301 * If strict host key checking has not been requested, allow
1302 * the connection but without MITM-able authentication or
1305 if (options.password_authentication) {
1306 error("Password authentication is disabled to avoid "
1307 "man-in-the-middle attacks.");
1308 options.password_authentication = 0;
1309 cancelled_forwarding = 1;
1311 if (options.kbd_interactive_authentication) {
1312 error("Keyboard-interactive authentication is disabled"
1313 " to avoid man-in-the-middle attacks.");
1314 options.kbd_interactive_authentication = 0;
1315 cancelled_forwarding = 1;
1317 if (options.forward_agent) {
1318 error("Agent forwarding is disabled to avoid "
1319 "man-in-the-middle attacks.");
1320 options.forward_agent = 0;
1321 cancelled_forwarding = 1;
1323 if (options.forward_x11) {
1324 error("X11 forwarding is disabled to avoid "
1325 "man-in-the-middle attacks.");
1326 options.forward_x11 = 0;
1327 cancelled_forwarding = 1;
1329 if (options.num_local_forwards > 0 ||
1330 options.num_remote_forwards > 0) {
1331 error("Port forwarding is disabled to avoid "
1332 "man-in-the-middle attacks.");
1333 options.num_local_forwards =
1334 options.num_remote_forwards = 0;
1335 cancelled_forwarding = 1;
1337 if (options.tun_open != SSH_TUNMODE_NO) {
1338 error("Tunnel forwarding is disabled to avoid "
1339 "man-in-the-middle attacks.");
1340 options.tun_open = SSH_TUNMODE_NO;
1341 cancelled_forwarding = 1;
1343 if (options.update_hostkeys != 0) {
1344 error("UpdateHostkeys is disabled because the host "
1345 "key is not trusted.");
1346 options.update_hostkeys = 0;
1348 if (options.exit_on_forward_failure && cancelled_forwarding)
1349 fatal("Error: forwarding disabled due to host key "
1353 * XXX Should permit the user to change to use the new id.
1354 * This could be done by converting the host key to an
1355 * identifying sentence, tell that the host identifies itself
1356 * by that sentence, and ask the user if they wish to
1357 * accept the authentication.
1361 fatal("internal error");
1365 if (options.check_host_ip && host_status != HOST_CHANGED &&
1366 ip_status == HOST_CHANGED) {
1367 snprintf(msg, sizeof(msg),
1368 "Warning: the %s host key for '%.200s' "
1369 "differs from the key for the IP address '%.128s'"
1370 "\nOffending key for IP in %s:%lu",
1371 type, host, ip, ip_found->file, ip_found->line);
1372 if (host_status == HOST_OK) {
1374 snprintf(msg + len, sizeof(msg) - len,
1375 "\nMatching host key in %s:%lu",
1376 host_found->file, host_found->line);
1378 if (options.strict_host_key_checking ==
1379 SSH_STRICT_HOSTKEY_ASK) {
1380 strlcat(msg, "\nAre you sure you want "
1381 "to continue connecting (yes/no)? ", sizeof(msg));
1382 if (!confirm(msg, NULL))
1384 } else if (options.strict_host_key_checking !=
1385 SSH_STRICT_HOSTKEY_OFF) {
1387 error("Exiting, you have requested strict checking.");
1394 if (!hostkey_trusted && options.update_hostkeys) {
1395 debug_f("hostkey not known or explicitly trusted: "
1396 "disabling UpdateHostkeys");
1397 options.update_hostkeys = 0;
1402 if (host_hostkeys != NULL)
1403 free_hostkeys(host_hostkeys);
1404 if (ip_hostkeys != NULL)
1405 free_hostkeys(ip_hostkeys);
1409 if (want_cert && host_status != HOST_REVOKED) {
1411 * No matching certificate. Downgrade cert to raw key and
1414 debug("No matching CA found. Retry with plain key");
1415 if ((r = sshkey_from_private(host_key, &raw_key)) != 0)
1416 fatal_fr(r, "decode key");
1417 if ((r = sshkey_drop_cert(raw_key)) != 0)
1418 fatal_r(r, "Couldn't drop certificate");
1422 sshkey_free(raw_key);
1425 if (host_hostkeys != NULL)
1426 free_hostkeys(host_hostkeys);
1427 if (ip_hostkeys != NULL)
1428 free_hostkeys(ip_hostkeys);
1432 /* returns 0 if key verifies or -1 if key does NOT verify */
1434 verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key,
1435 const struct ssh_conn_info *cinfo)
1438 int r = -1, flags = 0;
1439 char valid[64], *fp = NULL, *cafp = NULL;
1440 struct sshkey *plain = NULL;
1442 if ((fp = sshkey_fingerprint(host_key,
1443 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) {
1444 error_fr(r, "fingerprint host key");
1449 if (sshkey_is_cert(host_key)) {
1450 if ((cafp = sshkey_fingerprint(host_key->cert->signature_key,
1451 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) {
1452 error_fr(r, "fingerprint CA key");
1456 sshkey_format_cert_validity(host_key->cert,
1457 valid, sizeof(valid));
1458 debug("Server host certificate: %s %s, serial %llu "
1459 "ID \"%s\" CA %s %s valid %s",
1460 sshkey_ssh_name(host_key), fp,
1461 (unsigned long long)host_key->cert->serial,
1462 host_key->cert->key_id,
1463 sshkey_ssh_name(host_key->cert->signature_key), cafp,
1465 for (i = 0; i < host_key->cert->nprincipals; i++) {
1466 debug2("Server host certificate hostname: %s",
1467 host_key->cert->principals[i]);
1470 debug("Server host key: %s %s", sshkey_ssh_name(host_key), fp);
1473 if (sshkey_equal(previous_host_key, host_key)) {
1474 debug2_f("server host key %s %s matches cached key",
1475 sshkey_type(host_key), fp);
1480 /* Check in RevokedHostKeys file if specified */
1481 if (options.revoked_host_keys != NULL) {
1482 r = sshkey_check_revoked(host_key, options.revoked_host_keys);
1485 break; /* not revoked */
1486 case SSH_ERR_KEY_REVOKED:
1487 error("Host key %s %s revoked by file %s",
1488 sshkey_type(host_key), fp,
1489 options.revoked_host_keys);
1493 error_r(r, "Error checking host key %s %s in "
1494 "revoked keys file %s", sshkey_type(host_key),
1495 fp, options.revoked_host_keys);
1501 if (options.verify_host_key_dns) {
1503 * XXX certs are not yet supported for DNS, so downgrade
1504 * them and try the plain key.
1506 if ((r = sshkey_from_private(host_key, &plain)) != 0)
1508 if (sshkey_is_cert(plain))
1509 sshkey_drop_cert(plain);
1510 if (verify_host_key_dns(host, hostaddr, plain, &flags) == 0) {
1511 if (flags & DNS_VERIFY_FOUND) {
1512 if (options.verify_host_key_dns == 1 &&
1513 flags & DNS_VERIFY_MATCH &&
1514 flags & DNS_VERIFY_SECURE) {
1518 if (flags & DNS_VERIFY_MATCH) {
1519 matching_host_key_dns = 1;
1521 warn_changed_key(plain);
1522 error("Update the SSHFP RR in DNS "
1523 "with the new host key to get rid "
1524 "of this message.");
1529 r = check_host_key(host, cinfo, hostaddr, options.port, host_key,
1530 RDRW, 0, options.user_hostfiles, options.num_user_hostfiles,
1531 options.system_hostfiles, options.num_system_hostfiles,
1532 options.known_hosts_command);
1538 if (r == 0 && host_key != NULL) {
1539 sshkey_free(previous_host_key);
1540 r = sshkey_from_private(host_key, &previous_host_key);
1547 * Starts a dialog with the server, and authenticates the current user on the
1548 * server. This does not need any extra privileges. The basic connection
1549 * to the server must already have been established before this is called.
1550 * If login fails, this function prints an error and never returns.
1551 * This function does not require super-user privileges.
1554 ssh_login(struct ssh *ssh, Sensitive *sensitive, const char *orighost,
1555 struct sockaddr *hostaddr, u_short port, struct passwd *pw, int timeout_ms,
1556 const struct ssh_conn_info *cinfo)
1559 char *server_user, *local_user;
1562 local_user = xstrdup(pw->pw_name);
1563 server_user = options.user ? options.user : local_user;
1565 /* Convert the user-supplied hostname into all lowercase. */
1566 host = xstrdup(orighost);
1569 /* Exchange protocol version identification strings with the server. */
1570 if ((r = kex_exchange_identification(ssh, timeout_ms, NULL)) != 0)
1571 sshpkt_fatal(ssh, r, "banner exchange");
1573 /* Put the connection into non-blocking mode. */
1574 ssh_packet_set_nonblocking(ssh);
1577 /* authenticate user */
1578 debug("Authenticating to %s:%d as '%s'", host, port, server_user);
1579 ssh_kex2(ssh, host, hostaddr, port, cinfo);
1580 ssh_userauth2(ssh, local_user, server_user, host, sensitive);
1585 /* print all known host keys for a given host, but skip keys of given type */
1587 show_other_keys(struct hostkeys *hostkeys, struct sshkey *key)
1599 const struct hostkey_entry *found;
1601 for (i = 0; type[i] != -1; i++) {
1602 if (type[i] == key->type)
1604 if (!lookup_key_in_hostkeys_by_type(hostkeys, type[i],
1607 fp = sshkey_fingerprint(found->key,
1608 options.fingerprint_hash, SSH_FP_DEFAULT);
1609 ra = sshkey_fingerprint(found->key,
1610 options.fingerprint_hash, SSH_FP_RANDOMART);
1611 if (fp == NULL || ra == NULL)
1612 fatal_f("sshkey_fingerprint fail");
1613 logit("WARNING: %s key found for host %s\n"
1615 "%s key fingerprint %s.",
1616 sshkey_type(found->key),
1617 found->host, found->file, found->line,
1618 sshkey_type(found->key), fp);
1619 if (options.visual_host_key)
1629 warn_changed_key(struct sshkey *host_key)
1633 fp = sshkey_fingerprint(host_key, options.fingerprint_hash,
1636 fatal_f("sshkey_fingerprint fail");
1638 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1639 error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1640 error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1641 error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1642 error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1643 error("It is also possible that a host key has just been changed.");
1644 error("The fingerprint for the %s key sent by the remote host is\n%s.",
1645 sshkey_type(host_key), fp);
1646 error("Please contact your system administrator.");
1652 * Execute a local command
1655 ssh_local_cmd(const char *args)
1660 void (*osighand)(int);
1662 if (!options.permit_local_command ||
1663 args == NULL || !*args)
1666 if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
1667 shell = _PATH_BSHELL;
1669 osighand = ssh_signal(SIGCHLD, SIG_DFL);
1672 ssh_signal(SIGPIPE, SIG_DFL);
1673 debug3("Executing %s -c \"%s\"", shell, args);
1674 execl(shell, shell, "-c", args, (char *)NULL);
1675 error("Couldn't execute %s -c \"%s\": %s",
1676 shell, args, strerror(errno));
1678 } else if (pid == -1)
1679 fatal("fork failed: %.100s", strerror(errno));
1680 while (waitpid(pid, &status, 0) == -1)
1682 fatal("Couldn't wait for child: %s", strerror(errno));
1683 ssh_signal(SIGCHLD, osighand);
1685 if (!WIFEXITED(status))
1688 return (WEXITSTATUS(status));
1692 maybe_add_key_to_agent(const char *authfile, struct sshkey *private,
1693 const char *comment, const char *passphrase)
1695 int auth_sock = -1, r;
1696 const char *skprovider = NULL;
1698 if (options.add_keys_to_agent == 0)
1701 if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) {
1702 debug3("no authentication agent, not adding key");
1706 if (options.add_keys_to_agent == 2 &&
1707 !ask_permission("Add key %s (%s) to agent?", authfile, comment)) {
1708 debug3("user denied adding this key");
1712 if (sshkey_is_sk(private))
1713 skprovider = options.sk_provider;
1714 if ((r = ssh_add_identity_constrained(auth_sock, private,
1715 comment == NULL ? authfile : comment,
1716 options.add_keys_to_agent_lifespan,
1717 (options.add_keys_to_agent == 3), 0, skprovider, NULL, 0)) == 0)
1718 debug("identity added to agent: %s", authfile);
1720 debug("could not add identity to agent: %s (%d)", authfile, r);