Annotation of src/usr.bin/ssh/sshconnect.c, Revision 1.367
1.367 ! jsg 1: /* $OpenBSD: sshconnect.c,v 1.366 2024/01/11 01:45:36 djm Exp $ */
1.1 deraadt 2: /*
1.39 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * Code to connect to a remote host, and to perform the client side of the
7: * login (authentication) dialog.
1.78 deraadt 8: *
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".
1.39 deraadt 14: */
1.1 deraadt 15:
1.174 stevesk 16: #include <sys/types.h>
17: #include <sys/wait.h>
1.175 stevesk 18: #include <sys/stat.h>
1.187 stevesk 19: #include <sys/socket.h>
1.195 stevesk 20: #include <sys/time.h>
1.187 stevesk 21:
1.295 djm 22: #include <net/if.h>
1.187 stevesk 23: #include <netinet/in.h>
1.172 stevesk 24:
1.176 stevesk 25: #include <ctype.h>
1.190 stevesk 26: #include <errno.h>
1.216 dtucker 27: #include <fcntl.h>
1.191 stevesk 28: #include <netdb.h>
1.345 djm 29: #include <limits.h>
1.172 stevesk 30: #include <paths.h>
1.199 deraadt 31: #include <signal.h>
1.188 stevesk 32: #include <pwd.h>
1.198 stevesk 33: #include <stdio.h>
1.196 stevesk 34: #include <stdlib.h>
1.323 deraadt 35: #include <stdarg.h>
1.193 stevesk 36: #include <string.h>
1.192 stevesk 37: #include <unistd.h>
1.295 djm 38: #include <ifaddrs.h>
1.71 markus 39:
1.199 deraadt 40: #include "xmalloc.h"
1.91 markus 41: #include "ssh.h"
1.299 markus 42: #include "sshbuf.h"
1.1 deraadt 43: #include "packet.h"
1.300 markus 44: #include "sshkey.h"
1.71 markus 45: #include "sshconnect.h"
1.58 markus 46: #include "hostfile.h"
1.91 markus 47: #include "log.h"
1.251 millert 48: #include "misc.h"
1.91 markus 49: #include "readconf.h"
50: #include "atomicio.h"
1.140 jakob 51: #include "dns.h"
1.239 djm 52: #include "monitor_fdpass.h"
1.219 djm 53: #include "ssh2.h"
1.186 stevesk 54: #include "version.h"
1.252 djm 55: #include "authfile.h"
56: #include "ssherr.h"
1.266 jcs 57: #include "authfd.h"
1.309 djm 58: #include "kex.h"
1.310 djm 59:
1.279 markus 60: struct sshkey *previous_host_key = NULL;
1.59 markus 61:
1.169 stevesk 62: static int matching_host_key_dns = 0;
1.145 jakob 63:
1.227 djm 64: static pid_t proxy_command_pid = 0;
65:
1.124 markus 66: /* import */
1.307 djm 67: extern int debug_flag;
1.43 markus 68: extern Options options;
1.50 markus 69: extern char *__progname;
1.91 markus 70:
1.279 markus 71: static int show_other_keys(struct hostkeys *, struct sshkey *);
72: static void warn_changed_key(struct sshkey *);
1.132 markus 73:
1.239 djm 74: /* Expand a proxy command */
75: static char *
76: expand_proxy_command(const char *proxy_command, const char *user,
1.325 naddy 77: const char *host, const char *host_arg, int port)
1.239 djm 78: {
79: char *tmp, *ret, strport[NI_MAXSERV];
1.330 dtucker 80: const char *keyalias = options.host_key_alias ?
1.352 djm 81: options.host_key_alias : host_arg;
1.239 djm 82:
1.241 djm 83: snprintf(strport, sizeof strport, "%d", port);
1.239 djm 84: xasprintf(&tmp, "exec %s", proxy_command);
1.318 djm 85: ret = percent_expand(tmp,
86: "h", host,
1.330 dtucker 87: "k", keyalias,
1.318 djm 88: "n", host_arg,
89: "p", strport,
90: "r", options.user,
91: (char *)NULL);
1.239 djm 92: free(tmp);
93: return ret;
94: }
95:
96: /*
97: * Connect to the given ssh server using a proxy command that passes a
98: * a connected fd back to us.
99: */
100: static int
1.318 djm 101: ssh_proxy_fdpass_connect(struct ssh *ssh, const char *host,
102: const char *host_arg, u_short port, const char *proxy_command)
1.239 djm 103: {
104: char *command_string;
105: int sp[2], sock;
106: pid_t pid;
107: char *shell;
108:
109: if ((shell = getenv("SHELL")) == NULL)
110: shell = _PATH_BSHELL;
111:
1.317 deraadt 112: if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) == -1)
1.239 djm 113: fatal("Could not create socketpair to communicate with "
114: "proxy dialer: %.100s", strerror(errno));
115:
116: command_string = expand_proxy_command(proxy_command, options.user,
1.325 naddy 117: host, host_arg, port);
1.239 djm 118: debug("Executing proxy dialer command: %.500s", command_string);
119:
120: /* Fork and execute the proxy command. */
121: if ((pid = fork()) == 0) {
122: char *argv[10];
123:
124: close(sp[1]);
125: /* Redirect stdin and stdout. */
126: if (sp[0] != 0) {
1.317 deraadt 127: if (dup2(sp[0], 0) == -1)
1.239 djm 128: perror("dup2 stdin");
129: }
130: if (sp[0] != 1) {
1.317 deraadt 131: if (dup2(sp[0], 1) == -1)
1.239 djm 132: perror("dup2 stdout");
133: }
134: if (sp[0] >= 2)
135: close(sp[0]);
136:
137: /*
1.307 djm 138: * Stderr is left for non-ControlPersist connections is so
139: * error messages may be printed on the user's terminal.
1.239 djm 140: */
1.308 dtucker 141: if (!debug_flag && options.control_path != NULL &&
1.334 djm 142: options.control_persist && stdfd_devnull(0, 0, 1) == -1)
1.341 djm 143: error_f("stdfd_devnull failed");
1.307 djm 144:
1.239 djm 145: argv[0] = shell;
146: argv[1] = "-c";
147: argv[2] = command_string;
148: argv[3] = NULL;
149:
150: /*
151: * Execute the proxy command.
152: * Note that we gave up any extra privileges above.
153: */
154: execv(argv[0], argv);
155: perror(argv[0]);
156: exit(1);
157: }
158: /* Parent. */
1.317 deraadt 159: if (pid == -1)
1.239 djm 160: fatal("fork failed: %.100s", strerror(errno));
161: close(sp[0]);
162: free(command_string);
163:
164: if ((sock = mm_receive_fd(sp[1])) == -1)
165: fatal("proxy dialer did not pass back a connection");
1.271 markus 166: close(sp[1]);
1.239 djm 167:
168: while (waitpid(pid, NULL, 0) == -1)
169: if (errno != EINTR)
170: fatal("Couldn't wait for child: %s", strerror(errno));
171:
172: /* Set the connection file descriptors. */
1.286 djm 173: if (ssh_packet_set_connection(ssh, sock, sock) == NULL)
174: return -1; /* ssh_packet_set_connection logs error */
1.239 djm 175:
176: return 0;
177: }
178:
1.39 deraadt 179: /*
180: * Connect to the given ssh server using a proxy command.
181: */
1.109 itojun 182: static int
1.318 djm 183: ssh_proxy_connect(struct ssh *ssh, const char *host, const char *host_arg,
184: u_short port, const char *proxy_command)
1.1 deraadt 185: {
1.239 djm 186: char *command_string;
1.38 markus 187: int pin[2], pout[2];
1.69 deraadt 188: pid_t pid;
1.239 djm 189: char *shell;
1.237 markus 190:
1.226 djm 191: if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
1.201 djm 192: shell = _PATH_BSHELL;
1.38 markus 193:
194: /* Create pipes for communicating with the proxy. */
1.317 deraadt 195: if (pipe(pin) == -1 || pipe(pout) == -1)
1.38 markus 196: fatal("Could not create pipes to communicate with the proxy: %.100s",
1.118 deraadt 197: strerror(errno));
1.38 markus 198:
1.239 djm 199: command_string = expand_proxy_command(proxy_command, options.user,
1.325 naddy 200: host, host_arg, port);
1.38 markus 201: debug("Executing proxy command: %.500s", command_string);
202:
203: /* Fork and execute the proxy command. */
204: if ((pid = fork()) == 0) {
205: char *argv[10];
206:
207: /* Redirect stdin and stdout. */
208: close(pin[1]);
209: if (pin[0] != 0) {
1.317 deraadt 210: if (dup2(pin[0], 0) == -1)
1.38 markus 211: perror("dup2 stdin");
212: close(pin[0]);
213: }
214: close(pout[0]);
1.317 deraadt 215: if (dup2(pout[1], 1) == -1)
1.38 markus 216: perror("dup2 stdout");
217: /* Cannot be 1 because pin allocated two descriptors. */
218: close(pout[1]);
219:
1.307 djm 220: /*
221: * Stderr is left for non-ControlPersist connections is so
222: * error messages may be printed on the user's terminal.
223: */
1.308 dtucker 224: if (!debug_flag && options.control_path != NULL &&
1.334 djm 225: options.control_persist && stdfd_devnull(0, 0, 1) == -1)
1.341 djm 226: error_f("stdfd_devnull failed");
1.307 djm 227:
1.201 djm 228: argv[0] = shell;
1.38 markus 229: argv[1] = "-c";
230: argv[2] = command_string;
231: argv[3] = NULL;
232:
1.352 djm 233: /*
234: * Execute the proxy command. Note that we gave up any
235: * extra privileges above.
236: */
1.327 dtucker 237: ssh_signal(SIGPIPE, SIG_DFL);
1.89 markus 238: execv(argv[0], argv);
239: perror(argv[0]);
1.38 markus 240: exit(1);
241: }
242: /* Parent. */
1.317 deraadt 243: if (pid == -1)
1.38 markus 244: fatal("fork failed: %.100s", strerror(errno));
1.135 djm 245: else
246: proxy_command_pid = pid; /* save pid to clean up later */
1.38 markus 247:
248: /* Close child side of the descriptors. */
249: close(pin[0]);
250: close(pout[1]);
251:
252: /* Free the command name. */
1.238 djm 253: free(command_string);
1.38 markus 254:
255: /* Set the connection file descriptors. */
1.286 djm 256: if (ssh_packet_set_connection(ssh, pout[0], pin[1]) == NULL)
257: return -1; /* ssh_packet_set_connection logs error */
1.1 deraadt 258:
1.110 markus 259: return 0;
1.227 djm 260: }
261:
262: void
263: ssh_kill_proxy_command(void)
264: {
265: /*
266: * Send SIGHUP to proxy command if used. We don't wait() in
267: * case it hangs and instead rely on init to reap the child
268: */
269: if (proxy_command_pid > 1)
1.228 djm 270: kill(proxy_command_pid, SIGHUP);
1.1 deraadt 271: }
272:
1.39 deraadt 273: /*
1.295 djm 274: * Search a interface address list (returned from getifaddrs(3)) for an
1.298 djm 275: * address that matches the desired address family on the specified interface.
1.295 djm 276: * Returns 0 and fills in *resultp and *rlenp on success. Returns -1 on failure.
277: */
278: static int
279: check_ifaddrs(const char *ifname, int af, const struct ifaddrs *ifaddrs,
280: struct sockaddr_storage *resultp, socklen_t *rlenp)
281: {
282: struct sockaddr_in6 *sa6;
283: struct sockaddr_in *sa;
284: struct in6_addr *v6addr;
285: const struct ifaddrs *ifa;
286: int allow_local;
287:
288: /*
289: * Prefer addresses that are not loopback or linklocal, but use them
290: * if nothing else matches.
291: */
292: for (allow_local = 0; allow_local < 2; allow_local++) {
293: for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
294: if (ifa->ifa_addr == NULL || ifa->ifa_name == NULL ||
295: (ifa->ifa_flags & IFF_UP) == 0 ||
296: ifa->ifa_addr->sa_family != af ||
297: strcmp(ifa->ifa_name, options.bind_interface) != 0)
298: continue;
299: switch (ifa->ifa_addr->sa_family) {
300: case AF_INET:
301: sa = (struct sockaddr_in *)ifa->ifa_addr;
302: if (!allow_local && sa->sin_addr.s_addr ==
303: htonl(INADDR_LOOPBACK))
304: continue;
305: if (*rlenp < sizeof(struct sockaddr_in)) {
1.341 djm 306: error_f("v4 addr doesn't fit");
1.295 djm 307: return -1;
308: }
309: *rlenp = sizeof(struct sockaddr_in);
310: memcpy(resultp, sa, *rlenp);
311: return 0;
312: case AF_INET6:
313: sa6 = (struct sockaddr_in6 *)ifa->ifa_addr;
314: v6addr = &sa6->sin6_addr;
315: if (!allow_local &&
316: (IN6_IS_ADDR_LINKLOCAL(v6addr) ||
317: IN6_IS_ADDR_LOOPBACK(v6addr)))
318: continue;
319: if (*rlenp < sizeof(struct sockaddr_in6)) {
1.341 djm 320: error_f("v6 addr doesn't fit");
1.295 djm 321: return -1;
322: }
323: *rlenp = sizeof(struct sockaddr_in6);
324: memcpy(resultp, sa6, *rlenp);
325: return 0;
326: }
327: }
328: }
329: return -1;
330: }
331:
332: /*
1.303 dtucker 333: * Creates a socket for use as the ssh connection.
1.39 deraadt 334: */
1.109 itojun 335: static int
1.302 dtucker 336: ssh_create_socket(struct addrinfo *ai)
1.1 deraadt 337: {
1.301 dtucker 338: int sock, r;
1.295 djm 339: struct sockaddr_storage bindaddr;
340: socklen_t bindaddrlen = 0;
1.246 djm 341: struct addrinfo hints, *res = NULL;
1.295 djm 342: struct ifaddrs *ifaddrs = NULL;
343: char ntop[NI_MAXHOST];
1.1 deraadt 344:
1.217 dtucker 345: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.317 deraadt 346: if (sock == -1) {
1.240 djm 347: error("socket: %s", strerror(errno));
1.216 dtucker 348: return -1;
349: }
1.363 dtucker 350: (void)fcntl(sock, F_SETFD, FD_CLOEXEC);
1.345 djm 351:
352: /* Use interactive QOS (if specified) until authentication completed */
353: if (options.ip_qos_interactive != INT_MAX)
354: set_sock_tos(sock, options.ip_qos_interactive);
1.105 markus 355:
356: /* Bind the socket to an alternative local IP address */
1.302 dtucker 357: if (options.bind_address == NULL && options.bind_interface == NULL)
1.105 markus 358: return sock;
359:
1.295 djm 360: if (options.bind_address != NULL) {
1.246 djm 361: memset(&hints, 0, sizeof(hints));
362: hints.ai_family = ai->ai_family;
363: hints.ai_socktype = ai->ai_socktype;
364: hints.ai_protocol = ai->ai_protocol;
365: hints.ai_flags = AI_PASSIVE;
1.295 djm 366: if ((r = getaddrinfo(options.bind_address, NULL,
367: &hints, &res)) != 0) {
1.246 djm 368: error("getaddrinfo: %s: %s", options.bind_address,
1.295 djm 369: ssh_gai_strerror(r));
370: goto fail;
371: }
1.296 dtucker 372: if (res == NULL) {
1.295 djm 373: error("getaddrinfo: no addrs");
374: goto fail;
375: }
376: memcpy(&bindaddr, res->ai_addr, res->ai_addrlen);
377: bindaddrlen = res->ai_addrlen;
378: } else if (options.bind_interface != NULL) {
379: if ((r = getifaddrs(&ifaddrs)) != 0) {
380: error("getifaddrs: %s: %s", options.bind_interface,
1.352 djm 381: strerror(errno));
1.295 djm 382: goto fail;
383: }
384: bindaddrlen = sizeof(bindaddr);
385: if (check_ifaddrs(options.bind_interface, ai->ai_family,
386: ifaddrs, &bindaddr, &bindaddrlen) != 0) {
387: logit("getifaddrs: %s: no suitable addresses",
1.352 djm 388: options.bind_interface);
1.295 djm 389: goto fail;
1.246 djm 390: }
1.105 markus 391: }
1.295 djm 392: if ((r = getnameinfo((struct sockaddr *)&bindaddr, bindaddrlen,
393: ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST)) != 0) {
1.341 djm 394: error_f("getnameinfo failed: %s", ssh_gai_strerror(r));
1.295 djm 395: goto fail;
396: }
1.301 dtucker 397: if (bind(sock, (struct sockaddr *)&bindaddr, bindaddrlen) != 0) {
1.295 djm 398: error("bind %s: %s", ntop, strerror(errno));
399: goto fail;
1.38 markus 400: }
1.341 djm 401: debug_f("bound to %s", ntop);
1.295 djm 402: /* success */
403: goto out;
404: fail:
405: close(sock);
406: sock = -1;
407: out:
1.246 djm 408: if (res != NULL)
409: freeaddrinfo(res);
1.295 djm 410: if (ifaddrs != NULL)
411: freeifaddrs(ifaddrs);
1.38 markus 412: return sock;
1.1 deraadt 413: }
414:
1.282 djm 415: /*
1.49 markus 416: * Opens a TCP/IP connection to the remote server on the given host.
417: * The address of the remote host will be returned in hostaddr.
1.302 dtucker 418: * If port is 0, the default port will be used.
1.39 deraadt 419: * Connection_attempts specifies the maximum number of tries (one per
420: * second). If proxy_command is non-NULL, it specifies the command (with %h
421: * and %p substituted for host and port, respectively) to use to contact
422: * the daemon.
423: */
1.241 djm 424: static int
1.286 djm 425: ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop,
1.340 kn 426: struct sockaddr_storage *hostaddr, u_short port, int connection_attempts,
427: int *timeout_ms, int want_keepalive)
1.1 deraadt 428: {
1.313 dtucker 429: int on = 1, saved_timeout_ms = *timeout_ms;
1.290 djm 430: int oerrno, sock = -1, attempt;
1.90 markus 431: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.241 djm 432: struct addrinfo *ai;
1.38 markus 433:
1.341 djm 434: debug3_f("entering");
1.268 djm 435: memset(ntop, 0, sizeof(ntop));
436: memset(strport, 0, sizeof(strport));
1.38 markus 437:
1.181 markus 438: for (attempt = 0; attempt < connection_attempts; attempt++) {
1.200 markus 439: if (attempt > 0) {
440: /* Sleep a moment before retrying. */
441: sleep(1);
1.38 markus 442: debug("Trying again...");
1.200 markus 443: }
1.181 markus 444: /*
445: * Loop through addresses for this host, and try each one in
446: * sequence until the connection succeeds.
447: */
1.49 markus 448: for (ai = aitop; ai; ai = ai->ai_next) {
1.241 djm 449: if (ai->ai_family != AF_INET &&
1.290 djm 450: ai->ai_family != AF_INET6) {
451: errno = EAFNOSUPPORT;
1.49 markus 452: continue;
1.290 djm 453: }
1.49 markus 454: if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
455: ntop, sizeof(ntop), strport, sizeof(strport),
456: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.290 djm 457: oerrno = errno;
1.341 djm 458: error_f("getnameinfo failed");
1.290 djm 459: errno = oerrno;
1.49 markus 460: continue;
461: }
1.364 djm 462: if (options.address_family != AF_UNSPEC &&
463: ai->ai_family != options.address_family) {
464: debug2_f("skipping address [%s]:%s: "
465: "wrong address family", ntop, strport);
1.365 djm 466: errno = EAFNOSUPPORT;
1.364 djm 467: continue;
468: }
469:
1.49 markus 470: debug("Connecting to %.200s [%.100s] port %s.",
471: host, ntop, strport);
472:
473: /* Create a socket for connecting. */
1.302 dtucker 474: sock = ssh_create_socket(ai);
1.292 stsp 475: if (sock < 0) {
1.110 markus 476: /* Any error is already output */
1.290 djm 477: errno = 0;
1.49 markus 478: continue;
1.292 stsp 479: }
1.49 markus 480:
1.313 dtucker 481: *timeout_ms = saved_timeout_ms;
1.141 djm 482: if (timeout_connect(sock, ai->ai_addr, ai->ai_addrlen,
1.202 djm 483: timeout_ms) >= 0) {
1.49 markus 484: /* Successful connection. */
1.102 markus 485: memcpy(hostaddr, ai->ai_addr, ai->ai_addrlen);
1.38 markus 486: break;
1.49 markus 487: } else {
1.290 djm 488: oerrno = errno;
1.131 itojun 489: debug("connect to address %s port %s: %s",
490: ntop, strport, strerror(errno));
1.38 markus 491: close(sock);
1.181 markus 492: sock = -1;
1.290 djm 493: errno = oerrno;
1.38 markus 494: }
495: }
1.181 markus 496: if (sock != -1)
1.49 markus 497: break; /* Successful connection. */
1.38 markus 498: }
1.49 markus 499:
1.38 markus 500: /* Return failure if we didn't get a successful connection. */
1.181 markus 501: if (sock == -1) {
1.159 markus 502: error("ssh: connect to host %s port %s: %s",
1.290 djm 503: host, strport, errno == 0 ? "failure" : strerror(errno));
504: return -1;
1.130 itojun 505: }
1.38 markus 506:
507: debug("Connection established.");
1.90 markus 508:
1.155 markus 509: /* Set SO_KEEPALIVE if requested. */
1.202 djm 510: if (want_keepalive &&
1.90 markus 511: setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
1.317 deraadt 512: sizeof(on)) == -1)
1.90 markus 513: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.38 markus 514:
515: /* Set the connection. */
1.286 djm 516: if (ssh_packet_set_connection(ssh, sock, sock) == NULL)
517: return -1; /* ssh_packet_set_connection logs error */
1.1 deraadt 518:
1.319 djm 519: return 0;
1.59 markus 520: }
521:
1.241 djm 522: int
1.318 djm 523: ssh_connect(struct ssh *ssh, const char *host, const char *host_arg,
524: struct addrinfo *addrs, struct sockaddr_storage *hostaddr, u_short port,
1.340 kn 525: int connection_attempts, int *timeout_ms, int want_keepalive)
1.241 djm 526: {
1.314 markus 527: int in, out;
528:
1.241 djm 529: if (options.proxy_command == NULL) {
1.286 djm 530: return ssh_connect_direct(ssh, host, addrs, hostaddr, port,
1.340 kn 531: connection_attempts, timeout_ms, want_keepalive);
1.241 djm 532: } else if (strcmp(options.proxy_command, "-") == 0) {
1.317 deraadt 533: if ((in = dup(STDIN_FILENO)) == -1 ||
534: (out = dup(STDOUT_FILENO)) == -1) {
1.314 markus 535: if (in >= 0)
536: close(in);
1.341 djm 537: error_f("dup() in/out failed");
1.314 markus 538: return -1; /* ssh_packet_set_connection logs error */
539: }
540: if ((ssh_packet_set_connection(ssh, in, out)) == NULL)
1.286 djm 541: return -1; /* ssh_packet_set_connection logs error */
542: return 0;
1.241 djm 543: } else if (options.proxy_use_fdpass) {
1.318 djm 544: return ssh_proxy_fdpass_connect(ssh, host, host_arg, port,
1.241 djm 545: options.proxy_command);
546: }
1.318 djm 547: return ssh_proxy_connect(ssh, host, host_arg, port,
548: options.proxy_command);
1.241 djm 549: }
550:
1.96 markus 551: /* defaults to 'no' */
1.109 itojun 552: static int
1.312 dtucker 553: confirm(const char *prompt, const char *fingerprint)
1.1 deraadt 554: {
1.119 markus 555: const char *msg, *again = "Please type 'yes' or 'no': ";
1.312 dtucker 556: const char *again_fp = "Please type 'yes', 'no' or the fingerprint: ";
1.326 dtucker 557: char *p, *cp;
1.119 markus 558: int ret = -1;
1.96 markus 559:
560: if (options.batch_mode)
561: return 0;
1.312 dtucker 562: for (msg = prompt;;msg = fingerprint ? again_fp : again) {
1.326 dtucker 563: cp = p = read_passphrase(msg, RP_ECHO);
1.289 djm 564: if (p == NULL)
565: return 0;
1.326 dtucker 566: p += strspn(p, " \t"); /* skip leading whitespace */
567: p[strcspn(p, " \t\n")] = '\0'; /* remove trailing whitespace */
1.289 djm 568: if (p[0] == '\0' || strcasecmp(p, "no") == 0)
1.119 markus 569: ret = 0;
1.312 dtucker 570: else if (strcasecmp(p, "yes") == 0 || (fingerprint != NULL &&
1.332 djm 571: strcmp(p, fingerprint) == 0))
1.119 markus 572: ret = 1;
1.326 dtucker 573: free(cp);
1.119 markus 574: if (ret != -1)
575: return ret;
1.1 deraadt 576: }
577: }
578:
1.219 djm 579: static int
1.229 djm 580: sockaddr_is_local(struct sockaddr *hostaddr)
581: {
582: switch (hostaddr->sa_family) {
583: case AF_INET:
584: return (ntohl(((struct sockaddr_in *)hostaddr)->
585: sin_addr.s_addr) >> 24) == IN_LOOPBACKNET;
586: case AF_INET6:
587: return IN6_IS_ADDR_LOOPBACK(
588: &(((struct sockaddr_in6 *)hostaddr)->sin6_addr));
589: default:
590: return 0;
591: }
592: }
593:
594: /*
595: * Prepare the hostname and ip address strings that are used to lookup
596: * host keys in known_hosts files. These may have a port number appended.
597: */
598: void
599: get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr,
600: u_short port, char **hostfile_hostname, char **hostfile_ipaddr)
601: {
602: char ntop[NI_MAXHOST];
603:
604: /*
605: * We don't have the remote ip-address for connections
606: * using a proxy command
607: */
608: if (hostfile_ipaddr != NULL) {
609: if (options.proxy_command == NULL) {
610: if (getnameinfo(hostaddr, hostaddr->sa_len,
611: ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST) != 0)
1.367 ! jsg 612: fatal_f("getnameinfo failed");
1.229 djm 613: *hostfile_ipaddr = put_host_port(ntop, port);
614: } else {
615: *hostfile_ipaddr = xstrdup("<no hostip for proxy "
616: "command>");
617: }
618: }
619:
620: /*
621: * Allow the user to record the key under a different name or
622: * differentiate a non-standard port. This is useful for ssh
623: * tunneling over forwarded connections or if you run multiple
624: * sshd's on different ports on the same machine.
625: */
626: if (hostfile_hostname != NULL) {
627: if (options.host_key_alias != NULL) {
628: *hostfile_hostname = xstrdup(options.host_key_alias);
629: debug("using hostkeyalias: %s", *hostfile_hostname);
630: } else {
631: *hostfile_hostname = put_host_port(hostname, port);
632: }
633: }
634: }
635:
1.338 djm 636: /* returns non-zero if path appears in hostfiles, or 0 if not. */
637: static int
638: path_in_hostfiles(const char *path, char **hostfiles, u_int num_hostfiles)
639: {
640: u_int i;
641:
642: for (i = 0; i < num_hostfiles; i++) {
643: if (strcmp(path, hostfiles[i]) == 0)
644: return 1;
645: }
646: return 0;
647: }
648:
1.342 djm 649: struct find_by_key_ctx {
650: const char *host, *ip;
651: const struct sshkey *key;
652: char **names;
653: u_int nnames;
654: };
655:
656: /* Try to replace home directory prefix (per $HOME) with a ~/ sequence */
657: static char *
658: try_tilde_unexpand(const char *path)
659: {
660: char *home, *ret = NULL;
661: size_t l;
662:
663: if (*path != '/')
664: return xstrdup(path);
665: if ((home = getenv("HOME")) == NULL || (l = strlen(home)) == 0)
666: return xstrdup(path);
667: if (strncmp(path, home, l) != 0)
668: return xstrdup(path);
669: /*
670: * ensure we have matched on a path boundary: either the $HOME that
671: * we just compared ends with a '/' or the next character of the path
672: * must be a '/'.
673: */
674: if (home[l - 1] != '/' && path[l] != '/')
675: return xstrdup(path);
676: if (path[l] == '/')
677: l++;
678: xasprintf(&ret, "~/%s", path + l);
679: return ret;
680: }
681:
682: static int
683: hostkeys_find_by_key_cb(struct hostkey_foreach_line *l, void *_ctx)
684: {
685: struct find_by_key_ctx *ctx = (struct find_by_key_ctx *)_ctx;
686: char *path;
687:
688: /* we are looking for keys with names that *do not* match */
689: if ((l->match & HKF_MATCH_HOST) != 0)
690: return 0;
691: /* not interested in marker lines */
692: if (l->marker != MRK_NONE)
693: return 0;
694: /* we are only interested in exact key matches */
695: if (l->key == NULL || !sshkey_equal(ctx->key, l->key))
696: return 0;
697: path = try_tilde_unexpand(l->path);
698: debug_f("found matching key in %s:%lu", path, l->linenum);
699: ctx->names = xrecallocarray(ctx->names,
700: ctx->nnames, ctx->nnames + 1, sizeof(*ctx->names));
701: xasprintf(&ctx->names[ctx->nnames], "%s:%lu: %s", path, l->linenum,
702: strncmp(l->hosts, HASH_MAGIC, strlen(HASH_MAGIC)) == 0 ?
703: "[hashed name]" : l->hosts);
704: ctx->nnames++;
705: free(path);
706: return 0;
707: }
708:
709: static int
710: hostkeys_find_by_key_hostfile(const char *file, const char *which,
711: struct find_by_key_ctx *ctx)
712: {
713: int r;
714:
715: debug3_f("trying %s hostfile \"%s\"", which, file);
716: if ((r = hostkeys_foreach(file, hostkeys_find_by_key_cb, ctx,
1.346 djm 717: ctx->host, ctx->ip, HKF_WANT_PARSE_KEY, 0)) != 0) {
1.342 djm 718: if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
719: debug_f("hostkeys file %s does not exist", file);
720: return 0;
721: }
722: error_fr(r, "hostkeys_foreach failed for %s", file);
723: return r;
724: }
725: return 0;
726: }
727:
728: /*
729: * Find 'key' in known hosts file(s) that do not match host/ip.
730: * Used to display also-known-as information for previously-unseen hostkeys.
731: */
732: static void
733: hostkeys_find_by_key(const char *host, const char *ip, const struct sshkey *key,
734: char **user_hostfiles, u_int num_user_hostfiles,
735: char **system_hostfiles, u_int num_system_hostfiles,
736: char ***names, u_int *nnames)
737: {
1.343 dtucker 738: struct find_by_key_ctx ctx = {0, 0, 0, 0, 0};
1.342 djm 739: u_int i;
740:
741: *names = NULL;
742: *nnames = 0;
743:
744: if (key == NULL || sshkey_is_cert(key))
745: return;
746:
747: ctx.host = host;
748: ctx.ip = ip;
749: ctx.key = key;
750:
751: for (i = 0; i < num_user_hostfiles; i++) {
752: if (hostkeys_find_by_key_hostfile(user_hostfiles[i],
753: "user", &ctx) != 0)
754: goto fail;
755: }
756: for (i = 0; i < num_system_hostfiles; i++) {
757: if (hostkeys_find_by_key_hostfile(system_hostfiles[i],
758: "system", &ctx) != 0)
759: goto fail;
760: }
761: /* success */
762: *names = ctx.names;
763: *nnames = ctx.nnames;
764: ctx.names = NULL;
765: ctx.nnames = 0;
766: return;
767: fail:
768: for (i = 0; i < ctx.nnames; i++)
769: free(ctx.names[i]);
770: free(ctx.names);
771: }
772:
773: #define MAX_OTHER_NAMES 8 /* Maximum number of names to list */
774: static char *
775: other_hostkeys_message(const char *host, const char *ip,
776: const struct sshkey *key,
777: char **user_hostfiles, u_int num_user_hostfiles,
778: char **system_hostfiles, u_int num_system_hostfiles)
779: {
780: char *ret = NULL, **othernames = NULL;
781: u_int i, n, num_othernames = 0;
782:
783: hostkeys_find_by_key(host, ip, key,
784: user_hostfiles, num_user_hostfiles,
785: system_hostfiles, num_system_hostfiles,
786: &othernames, &num_othernames);
787: if (num_othernames == 0)
1.357 dtucker 788: return xstrdup("This key is not known by any other names.");
1.342 djm 789:
790: xasprintf(&ret, "This host key is known by the following other "
791: "names/addresses:");
792:
793: n = num_othernames;
794: if (n > MAX_OTHER_NAMES)
795: n = MAX_OTHER_NAMES;
796: for (i = 0; i < n; i++) {
797: xextendf(&ret, "\n", " %s", othernames[i]);
798: }
799: if (n < num_othernames) {
1.351 sthen 800: xextendf(&ret, "\n", " (%d additional names omitted)",
1.342 djm 801: num_othernames - n);
802: }
803: for (i = 0; i < num_othernames; i++)
804: free(othernames[i]);
805: free(othernames);
806: return ret;
807: }
808:
1.349 djm 809: void
810: load_hostkeys_command(struct hostkeys *hostkeys, const char *command_template,
811: const char *invocation, const struct ssh_conn_info *cinfo,
812: const struct sshkey *host_key, const char *hostfile_hostname)
813: {
814: int r, i, ac = 0;
815: char *key_fp = NULL, *keytext = NULL, *tmp;
816: char *command = NULL, *tag = NULL, **av = NULL;
817: FILE *f = NULL;
818: pid_t pid;
819: void (*osigchld)(int);
820:
821: xasprintf(&tag, "KnownHostsCommand-%s", invocation);
822:
823: if (host_key != NULL) {
824: if ((key_fp = sshkey_fingerprint(host_key,
825: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
826: fatal_f("sshkey_fingerprint failed");
827: if ((r = sshkey_to_base64(host_key, &keytext)) != 0)
828: fatal_fr(r, "sshkey_to_base64 failed");
829: }
830: /*
831: * NB. all returns later this function should go via "out" to
832: * ensure the original SIGCHLD handler is restored properly.
833: */
834: osigchld = ssh_signal(SIGCHLD, SIG_DFL);
835:
836: /* Turn the command into an argument vector */
1.353 djm 837: if (argv_split(command_template, &ac, &av, 0) != 0) {
1.349 djm 838: error("%s \"%s\" contains invalid quotes", tag,
1.352 djm 839: command_template);
1.349 djm 840: goto out;
841: }
842: if (ac == 0) {
843: error("%s \"%s\" yielded no arguments", tag,
844: command_template);
845: goto out;
846: }
847: for (i = 1; i < ac; i++) {
848: tmp = percent_dollar_expand(av[i],
849: DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
850: "H", hostfile_hostname,
851: "I", invocation,
852: "t", host_key == NULL ? "NONE" : sshkey_ssh_name(host_key),
853: "f", key_fp == NULL ? "NONE" : key_fp,
854: "K", keytext == NULL ? "NONE" : keytext,
855: (char *)NULL);
856: if (tmp == NULL)
857: fatal_f("percent_expand failed");
858: free(av[i]);
859: av[i] = tmp;
860: }
861: /* Prepare a printable command for logs, etc. */
862: command = argv_assemble(ac, av);
863:
864: if ((pid = subprocess(tag, command, ac, av, &f,
865: SSH_SUBPROCESS_STDOUT_CAPTURE|SSH_SUBPROCESS_UNSAFE_PATH|
866: SSH_SUBPROCESS_PRESERVE_ENV, NULL, NULL, NULL)) == 0)
867: goto out;
868:
869: load_hostkeys_file(hostkeys, hostfile_hostname, tag, f, 1);
870:
871: if (exited_cleanly(pid, tag, command, 0) != 0)
872: fatal("KnownHostsCommand failed");
873:
874: out:
875: if (f != NULL)
876: fclose(f);
877: ssh_signal(SIGCHLD, osigchld);
878: for (i = 0; i < ac; i++)
879: free(av[i]);
880: free(av);
881: free(tag);
882: free(command);
883: free(key_fp);
884: free(keytext);
885: }
886:
1.39 deraadt 887: /*
1.108 markus 888: * check whether the supplied host key is valid, return -1 if the key
1.234 djm 889: * is not valid. user_hostfile[0] will not be updated if 'readonly' is true.
1.39 deraadt 890: */
1.197 dtucker 891: #define RDRW 0
892: #define RDONLY 1
893: #define ROQUIET 2
1.109 itojun 894: static int
1.348 djm 895: check_host_key(char *hostname, const struct ssh_conn_info *cinfo,
896: struct sockaddr *hostaddr, u_short port,
897: struct sshkey *host_key, int readonly, int clobber_port,
1.234 djm 898: char **user_hostfiles, u_int num_user_hostfiles,
1.349 djm 899: char **system_hostfiles, u_int num_system_hostfiles,
900: const char *hostfile_command)
1.1 deraadt 901: {
1.338 djm 902: HostStatus host_status = -1, ip_status = -1;
1.279 markus 903: struct sshkey *raw_key = NULL;
1.189 dtucker 904: char *ip = NULL, *host = NULL;
1.204 grunk 905: char hostline[1000], *hostp, *fp, *ra;
1.119 markus 906: char msg[1024];
1.359 djm 907: const char *type, *fail_reason = NULL;
1.338 djm 908: const struct hostkey_entry *host_found = NULL, *ip_found = NULL;
1.312 dtucker 909: int len, cancelled_forwarding = 0, confirmed;
1.337 djm 910: int local = sockaddr_is_local(hostaddr);
1.280 markus 911: int r, want_cert = sshkey_is_cert(host_key), host_ip_differ = 0;
1.257 djm 912: int hostkey_trusted = 0; /* Known or explicitly accepted by user */
1.229 djm 913: struct hostkeys *host_hostkeys, *ip_hostkeys;
1.234 djm 914: u_int i;
1.49 markus 915:
916: /*
917: * Force accepting of the host key for loopback/localhost. The
918: * problem is that if the home directory is NFS-mounted to multiple
919: * machines, localhost will refer to a different machine in each of
920: * them, and the user will get bogus HOST_CHANGED warnings. This
921: * essentially disables host authentication for localhost; however,
922: * this is probably not a real problem.
923: */
1.111 markus 924: if (options.no_host_authentication_for_localhost == 1 && local &&
925: options.host_key_alias == NULL) {
1.88 markus 926: debug("Forcing accepting of host key for "
927: "loopback/localhost.");
1.338 djm 928: options.update_hostkeys = 0;
1.108 markus 929: return 0;
1.49 markus 930: }
1.42 markus 931:
932: /*
1.360 djm 933: * Don't ever try to write an invalid name to a known hosts file.
934: * Note: do this before get_hostfile_hostname_ipaddr() to catch
935: * '[' or ']' in the name before they are added.
936: */
937: if (strcspn(hostname, "@?*#[]|'\'\"\\") != strlen(hostname)) {
938: debug_f("invalid hostname \"%s\"; will not record: %s",
939: hostname, fail_reason);
940: readonly = RDONLY;
941: }
942:
943: /*
1.229 djm 944: * Prepare the hostname and address strings used for hostkey lookup.
945: * In some cases, these will have a port number appended.
1.42 markus 946: */
1.348 djm 947: get_hostfile_hostname_ipaddr(hostname, hostaddr,
948: clobber_port ? 0 : port, &host, &ip);
1.206 grunk 949:
950: /*
1.88 markus 951: * Turn off check_host_ip if the connection is to localhost, via proxy
952: * command or if we don't have a hostname to compare with
953: */
1.189 dtucker 954: if (options.check_host_ip && (local ||
955: strcmp(hostname, ip) == 0 || options.proxy_command != NULL))
1.88 markus 956: options.check_host_ip = 0;
1.86 markus 957:
1.229 djm 958: host_hostkeys = init_hostkeys();
1.234 djm 959: for (i = 0; i < num_user_hostfiles; i++)
1.346 djm 960: load_hostkeys(host_hostkeys, host, user_hostfiles[i], 0);
1.234 djm 961: for (i = 0; i < num_system_hostfiles; i++)
1.346 djm 962: load_hostkeys(host_hostkeys, host, system_hostfiles[i], 0);
1.349 djm 963: if (hostfile_command != NULL && !clobber_port) {
964: load_hostkeys_command(host_hostkeys, hostfile_command,
965: "HOSTNAME", cinfo, host_key, host);
966: }
1.229 djm 967:
968: ip_hostkeys = NULL;
969: if (!want_cert && options.check_host_ip) {
970: ip_hostkeys = init_hostkeys();
1.234 djm 971: for (i = 0; i < num_user_hostfiles; i++)
1.346 djm 972: load_hostkeys(ip_hostkeys, ip, user_hostfiles[i], 0);
1.234 djm 973: for (i = 0; i < num_system_hostfiles; i++)
1.346 djm 974: load_hostkeys(ip_hostkeys, ip, system_hostfiles[i], 0);
1.349 djm 975: if (hostfile_command != NULL && !clobber_port) {
976: load_hostkeys_command(ip_hostkeys, hostfile_command,
977: "ADDRESS", cinfo, host_key, ip);
978: }
1.84 markus 979: }
1.38 markus 980:
1.219 djm 981: retry:
1.229 djm 982: /* Reload these as they may have changed on cert->key downgrade */
1.280 markus 983: want_cert = sshkey_is_cert(host_key);
984: type = sshkey_type(host_key);
1.219 djm 985:
1.46 markus 986: /*
1.170 djm 987: * Check if the host key is present in the user's list of known
1.40 markus 988: * hosts or in the systemwide list.
989: */
1.229 djm 990: host_status = check_key_in_hostkeys(host_hostkeys, host_key,
991: &host_found);
1.347 djm 992:
1.349 djm 993: /*
994: * If there are no hostfiles, or if the hostkey was found via
995: * KnownHostsCommand, then don't try to touch the disk.
996: */
997: if (!readonly && (num_user_hostfiles == 0 ||
998: (host_found != NULL && host_found->note != 0)))
1.347 djm 999: readonly = RDONLY;
1.229 djm 1000:
1.40 markus 1001: /*
1002: * Also perform check for the ip address, skip the check if we are
1.219 djm 1003: * localhost, looking for a certificate, or the hostname was an ip
1004: * address to begin with.
1.40 markus 1005: */
1.229 djm 1006: if (!want_cert && ip_hostkeys != NULL) {
1007: ip_status = check_key_in_hostkeys(ip_hostkeys, host_key,
1008: &ip_found);
1.38 markus 1009: if (host_status == HOST_CHANGED &&
1.319 djm 1010: (ip_status != HOST_CHANGED ||
1.229 djm 1011: (ip_found != NULL &&
1.280 markus 1012: !sshkey_equal(ip_found->key, host_found->key))))
1.38 markus 1013: host_ip_differ = 1;
1014: } else
1015: ip_status = host_status;
1016:
1017: switch (host_status) {
1018: case HOST_OK:
1019: /* The host is known and the key matches. */
1.219 djm 1020: debug("Host '%.200s' is known and matches the %s host %s.",
1021: host, type, want_cert ? "certificate" : "key");
1.229 djm 1022: debug("Found %s in %s:%lu", want_cert ? "CA key" : "key",
1023: host_found->file, host_found->line);
1.350 djm 1024: if (want_cert) {
1025: if (sshkey_cert_check_host(host_key,
1026: options.host_key_alias == NULL ?
1027: hostname : options.host_key_alias, 0,
1028: options.ca_sign_algorithms, &fail_reason) != 0) {
1029: error("%s", fail_reason);
1030: goto fail;
1031: }
1032: /*
1033: * Do not attempt hostkey update if a certificate was
1034: * successfully matched.
1035: */
1036: if (options.update_hostkeys != 0) {
1037: options.update_hostkeys = 0;
1038: debug3_f("certificate host key in use; "
1039: "disabling UpdateHostkeys");
1040: }
1041: }
1.338 djm 1042: /* Turn off UpdateHostkeys if key was in system known_hosts */
1043: if (options.update_hostkeys != 0 &&
1044: (path_in_hostfiles(host_found->file,
1045: system_hostfiles, num_system_hostfiles) ||
1046: (ip_status == HOST_OK && ip_found != NULL &&
1047: path_in_hostfiles(ip_found->file,
1048: system_hostfiles, num_system_hostfiles)))) {
1049: options.update_hostkeys = 0;
1.341 djm 1050: debug3_f("host key found in GlobalKnownHostsFile; "
1051: "disabling UpdateHostkeys");
1.338 djm 1052: }
1.349 djm 1053: if (options.update_hostkeys != 0 && host_found->note) {
1054: options.update_hostkeys = 0;
1055: debug3_f("host key found via KnownHostsCommand; "
1056: "disabling UpdateHostkeys");
1057: }
1.88 markus 1058: if (options.check_host_ip && ip_status == HOST_NEW) {
1.219 djm 1059: if (readonly || want_cert)
1.138 itojun 1060: logit("%s host key for IP address "
1.108 markus 1061: "'%.128s' not in list of known hosts.",
1062: type, ip);
1.234 djm 1063: else if (!add_host_to_hostfile(user_hostfiles[0], ip,
1.160 djm 1064: host_key, options.hash_known_hosts))
1.138 itojun 1065: logit("Failed to add the %s host key for IP "
1.108 markus 1066: "address '%.128s' to the list of known "
1.262 dtucker 1067: "hosts (%.500s).", type, ip,
1.234 djm 1068: user_hostfiles[0]);
1.88 markus 1069: else
1.138 itojun 1070: logit("Warning: Permanently added the %s host "
1.108 markus 1071: "key for IP address '%.128s' to the list "
1072: "of known hosts.", type, ip);
1.209 grunk 1073: } else if (options.visual_host_key) {
1.259 djm 1074: fp = sshkey_fingerprint(host_key,
1.254 djm 1075: options.fingerprint_hash, SSH_FP_DEFAULT);
1.259 djm 1076: ra = sshkey_fingerprint(host_key,
1.254 djm 1077: options.fingerprint_hash, SSH_FP_RANDOMART);
1.259 djm 1078: if (fp == NULL || ra == NULL)
1.341 djm 1079: fatal_f("sshkey_fingerprint failed");
1.264 djm 1080: logit("Host key fingerprint is %s\n%s", fp, ra);
1.238 djm 1081: free(ra);
1082: free(fp);
1.38 markus 1083: }
1.257 djm 1084: hostkey_trusted = 1;
1.38 markus 1085: break;
1086: case HOST_NEW:
1.197 dtucker 1087: if (options.host_key_alias == NULL && port != 0 &&
1.348 djm 1088: port != SSH_DEFAULT_PORT && !clobber_port) {
1.197 dtucker 1089: debug("checking without port identifier");
1.348 djm 1090: if (check_host_key(hostname, cinfo, hostaddr, 0,
1091: host_key, ROQUIET, 1,
1092: user_hostfiles, num_user_hostfiles,
1.349 djm 1093: system_hostfiles, num_system_hostfiles,
1094: hostfile_command) == 0) {
1.197 dtucker 1095: debug("found matching key w/out port");
1096: break;
1097: }
1098: }
1.219 djm 1099: if (readonly || want_cert)
1.108 markus 1100: goto fail;
1.38 markus 1101: /* The host is new. */
1.285 djm 1102: if (options.strict_host_key_checking ==
1103: SSH_STRICT_HOSTKEY_YES) {
1.108 markus 1104: /*
1105: * User has requested strict host key checking. We
1106: * will not add the host key automatically. The only
1107: * alternative left is to abort.
1108: */
1109: error("No %s host key is known for %.200s and you "
1110: "have requested strict checking.", type, host);
1111: goto fail;
1.285 djm 1112: } else if (options.strict_host_key_checking ==
1113: SSH_STRICT_HOSTKEY_ASK) {
1.342 djm 1114: char *msg1 = NULL, *msg2 = NULL;
1115:
1116: xasprintf(&msg1, "The authenticity of host "
1117: "'%.200s (%s)' can't be established", host, ip);
1118:
1119: if (show_other_keys(host_hostkeys, host_key)) {
1120: xextendf(&msg1, "\n", "but keys of different "
1121: "type are already known for this host.");
1122: } else
1123: xextendf(&msg1, "", ".");
1.145 jakob 1124:
1.259 djm 1125: fp = sshkey_fingerprint(host_key,
1.254 djm 1126: options.fingerprint_hash, SSH_FP_DEFAULT);
1.259 djm 1127: ra = sshkey_fingerprint(host_key,
1.254 djm 1128: options.fingerprint_hash, SSH_FP_RANDOMART);
1.259 djm 1129: if (fp == NULL || ra == NULL)
1.341 djm 1130: fatal_f("sshkey_fingerprint failed");
1.342 djm 1131: xextendf(&msg1, "\n", "%s key fingerprint is %s.",
1132: type, fp);
1133: if (options.visual_host_key)
1134: xextendf(&msg1, "\n", "%s", ra);
1.145 jakob 1135: if (options.verify_host_key_dns) {
1.342 djm 1136: xextendf(&msg1, "\n",
1137: "%s host key fingerprint found in DNS.",
1138: matching_host_key_dns ?
1139: "Matching" : "No matching");
1.145 jakob 1140: }
1.342 djm 1141: /* msg2 informs for other names matching this key */
1142: if ((msg2 = other_hostkeys_message(host, ip, host_key,
1143: user_hostfiles, num_user_hostfiles,
1144: system_hostfiles, num_system_hostfiles)) != NULL)
1145: xextendf(&msg1, "\n", "%s", msg2);
1146:
1147: xextendf(&msg1, "\n",
1.108 markus 1148: "Are you sure you want to continue connecting "
1.342 djm 1149: "(yes/no/[fingerprint])? ");
1150:
1151: confirmed = confirm(msg1, fp);
1.238 djm 1152: free(ra);
1153: free(fp);
1.342 djm 1154: free(msg1);
1155: free(msg2);
1.312 dtucker 1156: if (!confirmed)
1.108 markus 1157: goto fail;
1.257 djm 1158: hostkey_trusted = 1; /* user explicitly confirmed */
1.38 markus 1159: }
1.161 djm 1160: /*
1.285 djm 1161: * If in "new" or "off" strict mode, add the key automatically
1162: * to the local known_hosts file.
1.161 djm 1163: */
1.88 markus 1164: if (options.check_host_ip && ip_status == HOST_NEW) {
1.229 djm 1165: snprintf(hostline, sizeof(hostline), "%s,%s", host, ip);
1.38 markus 1166: hostp = hostline;
1.161 djm 1167: if (options.hash_known_hosts) {
1168: /* Add hash of host and IP separately */
1.234 djm 1169: r = add_host_to_hostfile(user_hostfiles[0],
1170: host, host_key, options.hash_known_hosts) &&
1171: add_host_to_hostfile(user_hostfiles[0], ip,
1.161 djm 1172: host_key, options.hash_known_hosts);
1173: } else {
1174: /* Add unhashed "host,ip" */
1.234 djm 1175: r = add_host_to_hostfile(user_hostfiles[0],
1.161 djm 1176: hostline, host_key,
1177: options.hash_known_hosts);
1178: }
1179: } else {
1.234 djm 1180: r = add_host_to_hostfile(user_hostfiles[0], host,
1181: host_key, options.hash_known_hosts);
1.38 markus 1182: hostp = host;
1.161 djm 1183: }
1.38 markus 1184:
1.161 djm 1185: if (!r)
1.138 itojun 1186: logit("Failed to add the host to the list of known "
1.234 djm 1187: "hosts (%.500s).", user_hostfiles[0]);
1.38 markus 1188: else
1.138 itojun 1189: logit("Warning: Permanently added '%.200s' (%s) to the "
1.108 markus 1190: "list of known hosts.", hostp, type);
1.38 markus 1191: break;
1.220 djm 1192: case HOST_REVOKED:
1193: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1194: error("@ WARNING: REVOKED HOST KEY DETECTED! @");
1195: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1196: error("The %s host key for %s is marked as revoked.", type, host);
1197: error("This could mean that a stolen key is being used to");
1198: error("impersonate this host.");
1199:
1200: /*
1201: * If strict host key checking is in use, the user will have
1202: * to edit the key manually and we can only abort.
1203: */
1.285 djm 1204: if (options.strict_host_key_checking !=
1205: SSH_STRICT_HOSTKEY_OFF) {
1.220 djm 1206: error("%s host key for %.200s was revoked and you have "
1207: "requested strict checking.", type, host);
1208: goto fail;
1209: }
1210: goto continue_unsafe;
1211:
1.38 markus 1212: case HOST_CHANGED:
1.219 djm 1213: if (want_cert) {
1214: /*
1215: * This is only a debug() since it is valid to have
1216: * CAs with wildcard DNS matches that don't match
1217: * all hosts that one might visit.
1218: */
1219: debug("Host certificate authority does not "
1.229 djm 1220: "match %s in %s:%lu", CA_MARKER,
1221: host_found->file, host_found->line);
1.219 djm 1222: goto fail;
1223: }
1.197 dtucker 1224: if (readonly == ROQUIET)
1225: goto fail;
1.38 markus 1226: if (options.check_host_ip && host_ip_differ) {
1.158 avsm 1227: char *key_msg;
1.38 markus 1228: if (ip_status == HOST_NEW)
1.158 avsm 1229: key_msg = "is unknown";
1.38 markus 1230: else if (ip_status == HOST_OK)
1.158 avsm 1231: key_msg = "is unchanged";
1.38 markus 1232: else
1.158 avsm 1233: key_msg = "has a different value";
1.38 markus 1234: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1235: error("@ WARNING: POSSIBLE DNS SPOOFING DETECTED! @");
1236: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1.72 markus 1237: error("The %s host key for %s has changed,", type, host);
1.208 ian 1238: error("and the key for the corresponding IP address %s", ip);
1.158 avsm 1239: error("%s. This could either mean that", key_msg);
1.38 markus 1240: error("DNS SPOOFING is happening or the IP address for the host");
1.85 markus 1241: error("and its host key have changed at the same time.");
1.88 markus 1242: if (ip_status != HOST_NEW)
1.229 djm 1243: error("Offending key for IP in %s:%lu",
1244: ip_found->file, ip_found->line);
1.38 markus 1245: }
1246: /* The host key has changed. */
1.150 jakob 1247: warn_changed_key(host_key);
1.361 djm 1248: if (num_user_hostfiles > 0 || num_system_hostfiles > 0) {
1249: error("Add correct host key in %.100s to get rid "
1250: "of this message.", num_user_hostfiles > 0 ?
1251: user_hostfiles[0] : system_hostfiles[0]);
1252: }
1.280 markus 1253: error("Offending %s key in %s:%lu",
1254: sshkey_type(host_found->key),
1.229 djm 1255: host_found->file, host_found->line);
1.38 markus 1256:
1.40 markus 1257: /*
1258: * If strict host key checking is in use, the user will have
1259: * to edit the key manually and we can only abort.
1260: */
1.285 djm 1261: if (options.strict_host_key_checking !=
1262: SSH_STRICT_HOSTKEY_OFF) {
1.344 djm 1263: error("Host key for %.200s has changed and you have "
1264: "requested strict checking.", host);
1.108 markus 1265: goto fail;
1266: }
1.38 markus 1267:
1.220 djm 1268: continue_unsafe:
1.40 markus 1269: /*
1270: * If strict host key checking has not been requested, allow
1.144 djm 1271: * the connection but without MITM-able authentication or
1.194 stevesk 1272: * forwarding.
1.40 markus 1273: */
1.38 markus 1274: if (options.password_authentication) {
1.108 markus 1275: error("Password authentication is disabled to avoid "
1276: "man-in-the-middle attacks.");
1.38 markus 1277: options.password_authentication = 0;
1.210 dtucker 1278: cancelled_forwarding = 1;
1.144 djm 1279: }
1280: if (options.kbd_interactive_authentication) {
1281: error("Keyboard-interactive authentication is disabled"
1282: " to avoid man-in-the-middle attacks.");
1283: options.kbd_interactive_authentication = 0;
1.210 dtucker 1284: cancelled_forwarding = 1;
1.38 markus 1285: }
1286: if (options.forward_agent) {
1.108 markus 1287: error("Agent forwarding is disabled to avoid "
1288: "man-in-the-middle attacks.");
1.38 markus 1289: options.forward_agent = 0;
1.210 dtucker 1290: cancelled_forwarding = 1;
1.83 markus 1291: }
1292: if (options.forward_x11) {
1.108 markus 1293: error("X11 forwarding is disabled to avoid "
1294: "man-in-the-middle attacks.");
1.83 markus 1295: options.forward_x11 = 0;
1.210 dtucker 1296: cancelled_forwarding = 1;
1.83 markus 1297: }
1.108 markus 1298: if (options.num_local_forwards > 0 ||
1299: options.num_remote_forwards > 0) {
1300: error("Port forwarding is disabled to avoid "
1301: "man-in-the-middle attacks.");
1302: options.num_local_forwards =
1.118 deraadt 1303: options.num_remote_forwards = 0;
1.210 dtucker 1304: cancelled_forwarding = 1;
1.194 stevesk 1305: }
1306: if (options.tun_open != SSH_TUNMODE_NO) {
1307: error("Tunnel forwarding is disabled to avoid "
1308: "man-in-the-middle attacks.");
1309: options.tun_open = SSH_TUNMODE_NO;
1.210 dtucker 1310: cancelled_forwarding = 1;
1.339 djm 1311: }
1312: if (options.update_hostkeys != 0) {
1313: error("UpdateHostkeys is disabled because the host "
1314: "key is not trusted.");
1315: options.update_hostkeys = 0;
1.38 markus 1316: }
1.210 dtucker 1317: if (options.exit_on_forward_failure && cancelled_forwarding)
1318: fatal("Error: forwarding disabled due to host key "
1319: "check failure");
1.358 djm 1320:
1.40 markus 1321: /*
1322: * XXX Should permit the user to change to use the new id.
1323: * This could be done by converting the host key to an
1324: * identifying sentence, tell that the host identifies itself
1.354 dtucker 1325: * by that sentence, and ask the user if they wish to
1.40 markus 1326: * accept the authentication.
1327: */
1.38 markus 1328: break;
1.132 markus 1329: case HOST_FOUND:
1330: fatal("internal error");
1331: break;
1.88 markus 1332: }
1333:
1334: if (options.check_host_ip && host_status != HOST_CHANGED &&
1335: ip_status == HOST_CHANGED) {
1.119 markus 1336: snprintf(msg, sizeof(msg),
1337: "Warning: the %s host key for '%.200s' "
1338: "differs from the key for the IP address '%.128s'"
1.229 djm 1339: "\nOffending key for IP in %s:%lu",
1340: type, host, ip, ip_found->file, ip_found->line);
1.119 markus 1341: if (host_status == HOST_OK) {
1342: len = strlen(msg);
1343: snprintf(msg + len, sizeof(msg) - len,
1.229 djm 1344: "\nMatching host key in %s:%lu",
1345: host_found->file, host_found->line);
1.119 markus 1346: }
1.285 djm 1347: if (options.strict_host_key_checking ==
1348: SSH_STRICT_HOSTKEY_ASK) {
1.119 markus 1349: strlcat(msg, "\nAre you sure you want "
1350: "to continue connecting (yes/no)? ", sizeof(msg));
1.312 dtucker 1351: if (!confirm(msg, NULL))
1.108 markus 1352: goto fail;
1.285 djm 1353: } else if (options.strict_host_key_checking !=
1354: SSH_STRICT_HOSTKEY_OFF) {
1355: logit("%s", msg);
1356: error("Exiting, you have requested strict checking.");
1357: goto fail;
1.119 markus 1358: } else {
1.143 djm 1359: logit("%s", msg);
1.88 markus 1360: }
1.257 djm 1361: }
1362:
1363: if (!hostkey_trusted && options.update_hostkeys) {
1.341 djm 1364: debug_f("hostkey not known or explicitly trusted: "
1365: "disabling UpdateHostkeys");
1.257 djm 1366: options.update_hostkeys = 0;
1.38 markus 1367: }
1.82 provos 1368:
1.238 djm 1369: free(ip);
1370: free(host);
1.229 djm 1371: if (host_hostkeys != NULL)
1372: free_hostkeys(host_hostkeys);
1373: if (ip_hostkeys != NULL)
1374: free_hostkeys(ip_hostkeys);
1.108 markus 1375: return 0;
1376:
1377: fail:
1.337 djm 1378: if (want_cert && host_status != HOST_REVOKED) {
1.219 djm 1379: /*
1380: * No matching certificate. Downgrade cert to raw key and
1381: * search normally.
1382: */
1383: debug("No matching CA found. Retry with plain key");
1.280 markus 1384: if ((r = sshkey_from_private(host_key, &raw_key)) != 0)
1.341 djm 1385: fatal_fr(r, "decode key");
1.280 markus 1386: if ((r = sshkey_drop_cert(raw_key)) != 0)
1.341 djm 1387: fatal_r(r, "Couldn't drop certificate");
1.219 djm 1388: host_key = raw_key;
1389: goto retry;
1390: }
1.293 dtucker 1391: sshkey_free(raw_key);
1.238 djm 1392: free(ip);
1393: free(host);
1.229 djm 1394: if (host_hostkeys != NULL)
1395: free_hostkeys(host_hostkeys);
1396: if (ip_hostkeys != NULL)
1397: free_hostkeys(ip_hostkeys);
1.108 markus 1398: return -1;
1399: }
1400:
1.337 djm 1401: /* returns 0 if key verifies or -1 if key does NOT verify */
1.108 markus 1402: int
1.348 djm 1403: verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key,
1404: const struct ssh_conn_info *cinfo)
1.108 markus 1405: {
1.267 djm 1406: u_int i;
1.337 djm 1407: int r = -1, flags = 0;
1.267 djm 1408: char valid[64], *fp = NULL, *cafp = NULL;
1.252 djm 1409: struct sshkey *plain = NULL;
1.229 djm 1410:
1.252 djm 1411: if ((fp = sshkey_fingerprint(host_key,
1.254 djm 1412: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) {
1.341 djm 1413: error_fr(r, "fingerprint host key");
1.252 djm 1414: r = -1;
1415: goto out;
1416: }
1417:
1.267 djm 1418: if (sshkey_is_cert(host_key)) {
1419: if ((cafp = sshkey_fingerprint(host_key->cert->signature_key,
1420: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) {
1.341 djm 1421: error_fr(r, "fingerprint CA key");
1.267 djm 1422: r = -1;
1423: goto out;
1424: }
1425: sshkey_format_cert_validity(host_key->cert,
1426: valid, sizeof(valid));
1427: debug("Server host certificate: %s %s, serial %llu "
1428: "ID \"%s\" CA %s %s valid %s",
1429: sshkey_ssh_name(host_key), fp,
1.269 djm 1430: (unsigned long long)host_key->cert->serial,
1431: host_key->cert->key_id,
1.267 djm 1432: sshkey_ssh_name(host_key->cert->signature_key), cafp,
1433: valid);
1434: for (i = 0; i < host_key->cert->nprincipals; i++) {
1435: debug2("Server host certificate hostname: %s",
1436: host_key->cert->principals[i]);
1437: }
1438: } else {
1.276 djm 1439: debug("Server host key: %s %s", sshkey_ssh_name(host_key), fp);
1.267 djm 1440: }
1.252 djm 1441:
1442: if (sshkey_equal(previous_host_key, host_key)) {
1.341 djm 1443: debug2_f("server host key %s %s matches cached key",
1444: sshkey_type(host_key), fp);
1.252 djm 1445: r = 0;
1446: goto out;
1447: }
1448:
1449: /* Check in RevokedHostKeys file if specified */
1450: if (options.revoked_host_keys != NULL) {
1451: r = sshkey_check_revoked(host_key, options.revoked_host_keys);
1452: switch (r) {
1453: case 0:
1454: break; /* not revoked */
1455: case SSH_ERR_KEY_REVOKED:
1456: error("Host key %s %s revoked by file %s",
1457: sshkey_type(host_key), fp,
1458: options.revoked_host_keys);
1459: r = -1;
1460: goto out;
1461: default:
1.341 djm 1462: error_r(r, "Error checking host key %s %s in "
1463: "revoked keys file %s", sshkey_type(host_key),
1464: fp, options.revoked_host_keys);
1.252 djm 1465: r = -1;
1466: goto out;
1467: }
1.250 djm 1468: }
1469:
1.247 djm 1470: if (options.verify_host_key_dns) {
1471: /*
1472: * XXX certs are not yet supported for DNS, so downgrade
1473: * them and try the plain key.
1474: */
1.252 djm 1475: if ((r = sshkey_from_private(host_key, &plain)) != 0)
1476: goto out;
1477: if (sshkey_is_cert(plain))
1478: sshkey_drop_cert(plain);
1.247 djm 1479: if (verify_host_key_dns(host, hostaddr, plain, &flags) == 0) {
1480: if (flags & DNS_VERIFY_FOUND) {
1481: if (options.verify_host_key_dns == 1 &&
1482: flags & DNS_VERIFY_MATCH &&
1483: flags & DNS_VERIFY_SECURE) {
1.250 djm 1484: r = 0;
1.252 djm 1485: goto out;
1.247 djm 1486: }
1487: if (flags & DNS_VERIFY_MATCH) {
1488: matching_host_key_dns = 1;
1489: } else {
1.287 djm 1490: warn_changed_key(plain);
1491: error("Update the SSHFP RR in DNS "
1492: "with the new host key to get rid "
1493: "of this message.");
1.247 djm 1494: }
1.153 jakob 1495: }
1.140 jakob 1496: }
1497: }
1.348 djm 1498: r = check_host_key(host, cinfo, hostaddr, options.port, host_key,
1499: RDRW, 0, options.user_hostfiles, options.num_user_hostfiles,
1.349 djm 1500: options.system_hostfiles, options.num_system_hostfiles,
1501: options.known_hosts_command);
1.250 djm 1502:
1.252 djm 1503: out:
1504: sshkey_free(plain);
1505: free(fp);
1.267 djm 1506: free(cafp);
1.337 djm 1507: if (r == 0 && host_key != NULL) {
1508: sshkey_free(previous_host_key);
1509: r = sshkey_from_private(host_key, &previous_host_key);
1.250 djm 1510: }
1511:
1512: return r;
1.51 markus 1513: }
1.70 markus 1514:
1.51 markus 1515: /*
1516: * Starts a dialog with the server, and authenticates the current user on the
1517: * server. This does not need any extra privileges. The basic connection
1518: * to the server must already have been established before this is called.
1519: * If login fails, this function prints an error and never returns.
1520: * This function does not require super-user privileges.
1521: */
1522: void
1.309 djm 1523: ssh_login(struct ssh *ssh, Sensitive *sensitive, const char *orighost,
1.348 djm 1524: struct sockaddr *hostaddr, u_short port, struct passwd *pw, int timeout_ms,
1525: const struct ssh_conn_info *cinfo)
1.51 markus 1526: {
1.241 djm 1527: char *host;
1.70 markus 1528: char *server_user, *local_user;
1.329 djm 1529: int r;
1.70 markus 1530:
1531: local_user = xstrdup(pw->pw_name);
1532: server_user = options.user ? options.user : local_user;
1.51 markus 1533:
1534: /* Convert the user-supplied hostname into all lowercase. */
1535: host = xstrdup(orighost);
1.241 djm 1536: lowercase(host);
1.51 markus 1537:
1538: /* Exchange protocol version identification strings with the server. */
1.329 djm 1539: if ((r = kex_exchange_identification(ssh, timeout_ms, NULL)) != 0)
1540: sshpkt_fatal(ssh, r, "banner exchange");
1.51 markus 1541:
1542: /* Put the connection into non-blocking mode. */
1.309 djm 1543: ssh_packet_set_nonblocking(ssh);
1.51 markus 1544:
1545: /* key exchange */
1546: /* authenticate user */
1.261 dtucker 1547: debug("Authenticating to %s:%d as '%s'", host, port, server_user);
1.348 djm 1548: ssh_kex2(ssh, host, hostaddr, port, cinfo);
1.309 djm 1549: ssh_userauth2(ssh, local_user, server_user, host, sensitive);
1.238 djm 1550: free(local_user);
1.315 dtucker 1551: free(host);
1.132 markus 1552: }
1553:
1554: /* print all known host keys for a given host, but skip keys of given type */
1555: static int
1.279 markus 1556: show_other_keys(struct hostkeys *hostkeys, struct sshkey *key)
1.132 markus 1557: {
1.242 djm 1558: int type[] = {
1559: KEY_RSA,
1.366 djm 1560: #ifdef WITH_DSA
1.242 djm 1561: KEY_DSA,
1.366 djm 1562: #endif
1.242 djm 1563: KEY_ECDSA,
1564: KEY_ED25519,
1.297 markus 1565: KEY_XMSS,
1.242 djm 1566: -1
1567: };
1.229 djm 1568: int i, ret = 0;
1569: char *fp, *ra;
1570: const struct hostkey_entry *found;
1.132 markus 1571:
1572: for (i = 0; type[i] != -1; i++) {
1573: if (type[i] == key->type)
1574: continue;
1.335 djm 1575: if (!lookup_key_in_hostkeys_by_type(hostkeys, type[i],
1576: -1, &found))
1.132 markus 1577: continue;
1.259 djm 1578: fp = sshkey_fingerprint(found->key,
1.254 djm 1579: options.fingerprint_hash, SSH_FP_DEFAULT);
1.259 djm 1580: ra = sshkey_fingerprint(found->key,
1.254 djm 1581: options.fingerprint_hash, SSH_FP_RANDOMART);
1.259 djm 1582: if (fp == NULL || ra == NULL)
1.341 djm 1583: fatal_f("sshkey_fingerprint fail");
1.229 djm 1584: logit("WARNING: %s key found for host %s\n"
1585: "in %s:%lu\n"
1586: "%s key fingerprint %s.",
1.300 markus 1587: sshkey_type(found->key),
1.229 djm 1588: found->host, found->file, found->line,
1.300 markus 1589: sshkey_type(found->key), fp);
1.229 djm 1590: if (options.visual_host_key)
1591: logit("%s", ra);
1.238 djm 1592: free(ra);
1593: free(fp);
1.229 djm 1594: ret = 1;
1.132 markus 1595: }
1.229 djm 1596: return ret;
1.150 jakob 1597: }
1598:
1599: static void
1.279 markus 1600: warn_changed_key(struct sshkey *host_key)
1.150 jakob 1601: {
1602: char *fp;
1603:
1.259 djm 1604: fp = sshkey_fingerprint(host_key, options.fingerprint_hash,
1.254 djm 1605: SSH_FP_DEFAULT);
1.259 djm 1606: if (fp == NULL)
1.341 djm 1607: fatal_f("sshkey_fingerprint fail");
1.150 jakob 1608:
1609: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1610: error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @");
1611: error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
1612: error("IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!");
1613: error("Someone could be eavesdropping on you right now (man-in-the-middle attack)!");
1.230 markus 1614: error("It is also possible that a host key has just been changed.");
1.150 jakob 1615: error("The fingerprint for the %s key sent by the remote host is\n%s.",
1.300 markus 1616: sshkey_type(host_key), fp);
1.150 jakob 1617: error("Please contact your system administrator.");
1618:
1.238 djm 1619: free(fp);
1.171 reyk 1620: }
1621:
1622: /*
1623: * Execute a local command
1624: */
1625: int
1626: ssh_local_cmd(const char *args)
1627: {
1628: char *shell;
1629: pid_t pid;
1630: int status;
1.231 djm 1631: void (*osighand)(int);
1.171 reyk 1632:
1633: if (!options.permit_local_command ||
1634: args == NULL || !*args)
1635: return (1);
1636:
1.226 djm 1637: if ((shell = getenv("SHELL")) == NULL || *shell == '\0')
1.171 reyk 1638: shell = _PATH_BSHELL;
1639:
1.327 dtucker 1640: osighand = ssh_signal(SIGCHLD, SIG_DFL);
1.171 reyk 1641: pid = fork();
1642: if (pid == 0) {
1.327 dtucker 1643: ssh_signal(SIGPIPE, SIG_DFL);
1.171 reyk 1644: debug3("Executing %s -c \"%s\"", shell, args);
1645: execl(shell, shell, "-c", args, (char *)NULL);
1646: error("Couldn't execute %s -c \"%s\": %s",
1647: shell, args, strerror(errno));
1648: _exit(1);
1649: } else if (pid == -1)
1650: fatal("fork failed: %.100s", strerror(errno));
1651: while (waitpid(pid, &status, 0) == -1)
1652: if (errno != EINTR)
1653: fatal("Couldn't wait for child: %s", strerror(errno));
1.327 dtucker 1654: ssh_signal(SIGCHLD, osighand);
1.171 reyk 1655:
1656: if (!WIFEXITED(status))
1657: return (1);
1658:
1659: return (WEXITSTATUS(status));
1.266 jcs 1660: }
1661:
1662: void
1.328 djm 1663: maybe_add_key_to_agent(const char *authfile, struct sshkey *private,
1664: const char *comment, const char *passphrase)
1.266 jcs 1665: {
1666: int auth_sock = -1, r;
1.321 djm 1667: const char *skprovider = NULL;
1.266 jcs 1668:
1669: if (options.add_keys_to_agent == 0)
1670: return;
1671:
1672: if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) {
1673: debug3("no authentication agent, not adding key");
1674: return;
1675: }
1676:
1677: if (options.add_keys_to_agent == 2 &&
1678: !ask_permission("Add key %s (%s) to agent?", authfile, comment)) {
1679: debug3("user denied adding this key");
1.273 dtucker 1680: close(auth_sock);
1.266 jcs 1681: return;
1682: }
1.322 markus 1683: if (sshkey_is_sk(private))
1.321 djm 1684: skprovider = options.sk_provider;
1.328 djm 1685: if ((r = ssh_add_identity_constrained(auth_sock, private,
1.331 djm 1686: comment == NULL ? authfile : comment,
1687: options.add_keys_to_agent_lifespan,
1.356 djm 1688: (options.add_keys_to_agent == 3), 0, skprovider, NULL, 0)) == 0)
1.266 jcs 1689: debug("identity added to agent: %s", authfile);
1690: else
1691: debug("could not add identity to agent: %s (%d)", authfile, r);
1.273 dtucker 1692: close(auth_sock);
1.1 deraadt 1693: }
![[BACK]](/icons/back.gif){kind=icon}
Return to sshconnect.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh