Annotation of src/usr.bin/ssh/sshd.c, Revision 1.414
1.414 ! djm 1: /* $OpenBSD: sshd.c,v 1.413 2013/12/30 23:52:28 djm Exp $ */
1.86 markus 2: /*
1.65 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
1.126 deraadt 6: * This program is the ssh daemon. It listens for connections from clients,
7: * and performs authentication, executes use commands or shell, and forwards
1.65 deraadt 8: * information to/from the application to the user client over an encrypted
1.126 deraadt 9: * connection. This can also handle forwarding of X11, TCP/IP, and
10: * authentication agent connections.
1.98 markus 11: *
1.126 deraadt 12: * As far as I am concerned, the code I have written for this software
13: * can be used freely for any purpose. Any derived versions of this
14: * software must be clearly marked as such, and if the derived work is
15: * incompatible with the protocol description in the RFC file, it must be
16: * called by a name other than "ssh" or "Secure Shell".
17: *
18: * SSH2 implementation:
1.231 provos 19: * Privilege Separation:
1.126 deraadt 20: *
1.231 provos 21: * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
22: * Copyright (c) 2002 Niels Provos. All rights reserved.
1.126 deraadt 23: *
24: * Redistribution and use in source and binary forms, with or without
25: * modification, are permitted provided that the following conditions
26: * are met:
27: * 1. Redistributions of source code must retain the above copyright
28: * notice, this list of conditions and the following disclaimer.
29: * 2. Redistributions in binary form must reproduce the above copyright
30: * notice, this list of conditions and the following disclaimer in the
31: * documentation and/or other materials provided with the distribution.
32: *
33: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
34: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
36: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
37: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
38: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
39: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
40: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
41: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
42: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.65 deraadt 43: */
1.1 deraadt 44:
1.343 deraadt 45: #include <sys/types.h>
1.320 stevesk 46: #include <sys/ioctl.h>
1.321 stevesk 47: #include <sys/wait.h>
1.343 deraadt 48: #include <sys/tree.h>
1.323 stevesk 49: #include <sys/stat.h>
1.334 stevesk 50: #include <sys/socket.h>
1.340 stevesk 51: #include <sys/time.h>
1.357 djm 52: #include <sys/queue.h>
1.319 stevesk 53:
1.336 stevesk 54: #include <errno.h>
1.335 stevesk 55: #include <fcntl.h>
1.338 stevesk 56: #include <netdb.h>
1.319 stevesk 57: #include <paths.h>
1.333 stevesk 58: #include <pwd.h>
1.322 stevesk 59: #include <signal.h>
1.342 stevesk 60: #include <stdio.h>
1.341 stevesk 61: #include <stdlib.h>
1.339 stevesk 62: #include <string.h>
1.344 dtucker 63: #include <unistd.h>
1.1 deraadt 64:
1.155 markus 65: #include <openssl/dh.h>
66: #include <openssl/bn.h>
1.226 markus 67: #include <openssl/md5.h>
1.231 provos 68: #include <openssl/rand.h>
1.155 markus 69:
1.343 deraadt 70: #include "xmalloc.h"
1.155 markus 71: #include "ssh.h"
72: #include "ssh1.h"
73: #include "ssh2.h"
1.1 deraadt 74: #include "rsa.h"
1.171 djm 75: #include "sshpty.h"
1.1 deraadt 76: #include "packet.h"
1.155 markus 77: #include "log.h"
1.343 deraadt 78: #include "buffer.h"
1.1 deraadt 79: #include "servconf.h"
80: #include "uidswap.h"
1.33 markus 81: #include "compat.h"
1.155 markus 82: #include "cipher.h"
1.343 deraadt 83: #include "key.h"
1.98 markus 84: #include "kex.h"
1.129 provos 85: #include "dh.h"
1.98 markus 86: #include "myproposal.h"
1.108 markus 87: #include "authfile.h"
1.154 markus 88: #include "pathnames.h"
1.155 markus 89: #include "atomicio.h"
90: #include "canohost.h"
1.343 deraadt 91: #include "hostfile.h"
1.155 markus 92: #include "auth.h"
1.404 markus 93: #include "authfd.h"
1.155 markus 94: #include "misc.h"
1.294 djm 95: #include "msg.h"
1.186 markus 96: #include "dispatch.h"
1.206 stevesk 97: #include "channels.h"
1.230 provos 98: #include "session.h"
1.231 provos 99: #include "monitor_mm.h"
100: #include "monitor.h"
1.343 deraadt 101: #ifdef GSSAPI
102: #include "ssh-gss.h"
103: #endif
1.231 provos 104: #include "monitor_wrap.h"
1.367 andreas 105: #include "roaming.h"
1.385 djm 106: #include "ssh-sandbox.h"
1.332 stevesk 107: #include "version.h"
1.1 deraadt 108:
109: #ifdef LIBWRAP
110: #include <tcpd.h>
111: #include <syslog.h>
112: int allow_severity = LOG_INFO;
113: int deny_severity = LOG_WARNING;
114: #endif /* LIBWRAP */
115:
116: #ifndef O_NOCTTY
117: #define O_NOCTTY 0
118: #endif
119:
1.296 djm 120: /* Re-exec fds */
121: #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
122: #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
123: #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3)
124: #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4)
125:
1.138 markus 126: extern char *__progname;
127:
1.1 deraadt 128: /* Server configuration options. */
129: ServerOptions options;
130:
131: /* Name of the server configuration file. */
1.154 markus 132: char *config_file_name = _PATH_SERVER_CONFIG_FILE;
1.1 deraadt 133:
1.105 markus 134: /*
1.65 deraadt 135: * Debug mode flag. This can be set on the command line. If debug
136: * mode is enabled, extra debugging output will be sent to the system
137: * log, the daemon will not go to background, and will exit after processing
138: * the first connection.
139: */
1.1 deraadt 140: int debug_flag = 0;
141:
1.203 stevesk 142: /* Flag indicating that the daemon should only test the configuration and keys. */
143: int test_flag = 0;
144:
1.1 deraadt 145: /* Flag indicating that the daemon is being started from inetd. */
146: int inetd_flag = 0;
147:
1.135 markus 148: /* Flag indicating that sshd should not detach and become a daemon. */
149: int no_daemon_flag = 0;
150:
1.47 markus 151: /* debug goes to stderr unless inetd_flag is set */
152: int log_stderr = 0;
153:
1.1 deraadt 154: /* Saved arguments to main(). */
155: char **saved_argv;
156:
1.294 djm 157: /* re-exec */
158: int rexeced_flag = 0;
159: int rexec_flag = 1;
160: int rexec_argc = 0;
161: char **rexec_argv;
162:
1.66 markus 163: /*
1.75 markus 164: * The sockets that the server is listening; this is used in the SIGHUP
165: * signal handler.
1.66 markus 166: */
1.75 markus 167: #define MAX_LISTEN_SOCKS 16
168: int listen_socks[MAX_LISTEN_SOCKS];
169: int num_listen_socks = 0;
1.1 deraadt 170:
1.66 markus 171: /*
172: * the client's version string, passed by sshd2 in compat mode. if != NULL,
173: * sshd will skip the version-number exchange
174: */
1.61 markus 175: char *client_version_string = NULL;
1.96 markus 176: char *server_version_string = NULL;
1.1 deraadt 177:
1.189 markus 178: /* for rekeying XXX fixme */
179: Kex *xxx_kex;
180:
1.404 markus 181: /* Daemon's agent connection */
182: AuthenticationConnection *auth_conn = NULL;
183: int have_agent = 0;
184:
1.66 markus 185: /*
186: * Any really sensitive data in the application is contained in this
187: * structure. The idea is that this structure could be locked into memory so
188: * that the pages do not get written into swap. However, there are some
189: * problems. The private key contains BIGNUMs, and we do not (in principle)
190: * have access to the internals of them, and locking just the structure is
191: * not very useful. Currently, memory locking is not implemented.
192: */
1.64 markus 193: struct {
1.174 deraadt 194: Key *server_key; /* ephemeral server key */
1.134 markus 195: Key *ssh1_host_key; /* ssh1 host key */
196: Key **host_keys; /* all private host keys */
1.404 markus 197: Key **host_pubkeys; /* all public host keys */
1.373 djm 198: Key **host_certificates; /* all public host certificates */
1.134 markus 199: int have_ssh1_key;
200: int have_ssh2_key;
1.169 markus 201: u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
1.1 deraadt 202: } sensitive_data;
203:
1.66 markus 204: /*
1.151 markus 205: * Flag indicating whether the RSA server key needs to be regenerated.
206: * Is set in the SIGALRM handler and cleared when the key is regenerated.
1.66 markus 207: */
1.212 markus 208: static volatile sig_atomic_t key_do_regen = 0;
1.1 deraadt 209:
1.199 markus 210: /* This is set to true when a signal is received. */
1.212 markus 211: static volatile sig_atomic_t received_sighup = 0;
212: static volatile sig_atomic_t received_sigterm = 0;
1.1 deraadt 213:
1.96 markus 214: /* session identifier, used by RSA-auth */
1.140 markus 215: u_char session_id[16];
1.96 markus 216:
1.108 markus 217: /* same for ssh2 */
1.140 markus 218: u_char *session_id2 = NULL;
1.269 markus 219: u_int session_id2_len = 0;
1.108 markus 220:
1.125 markus 221: /* record remote hostname or ip */
1.140 markus 222: u_int utmp_len = MAXHOSTNAMELEN;
1.125 markus 223:
1.211 markus 224: /* options.max_startup sized array of fd ints */
225: int *startup_pipes = NULL;
226: int startup_pipe; /* in child */
227:
1.231 provos 228: /* variables used for privilege separation */
1.337 dtucker 229: int use_privsep = -1;
1.285 dtucker 230: struct monitor *pmonitor = NULL;
1.386 djm 231: int privsep_is_preauth = 1;
1.231 provos 232:
1.278 markus 233: /* global authentication context */
234: Authctxt *the_authctxt = NULL;
235:
1.337 dtucker 236: /* sshd_config buffer */
237: Buffer cfg;
238:
1.299 dtucker 239: /* message to be displayed after login */
240: Buffer loginmsg;
241:
1.1 deraadt 242: /* Prototypes for various functions defined later in this file. */
1.200 itojun 243: void destroy_sensitive_data(void);
1.231 provos 244: void demote_sensitive_data(void);
1.87 markus 245:
1.200 itojun 246: static void do_ssh1_kex(void);
247: static void do_ssh2_kex(void);
1.129 provos 248:
1.87 markus 249: /*
1.75 markus 250: * Close all listening sockets
251: */
1.200 itojun 252: static void
1.75 markus 253: close_listen_socks(void)
254: {
255: int i;
1.250 deraadt 256:
1.75 markus 257: for (i = 0; i < num_listen_socks; i++)
258: close(listen_socks[i]);
259: num_listen_socks = -1;
260: }
261:
1.211 markus 262: static void
263: close_startup_pipes(void)
264: {
265: int i;
1.250 deraadt 266:
1.211 markus 267: if (startup_pipes)
268: for (i = 0; i < options.max_startups; i++)
269: if (startup_pipes[i] != -1)
270: close(startup_pipes[i]);
271: }
272:
1.75 markus 273: /*
1.65 deraadt 274: * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
275: * the effect is to reread the configuration file (and to regenerate
276: * the server key).
277: */
1.327 deraadt 278:
279: /*ARGSUSED*/
1.200 itojun 280: static void
1.64 markus 281: sighup_handler(int sig)
1.1 deraadt 282: {
1.210 deraadt 283: int save_errno = errno;
284:
1.64 markus 285: received_sighup = 1;
286: signal(SIGHUP, sighup_handler);
1.210 deraadt 287: errno = save_errno;
1.1 deraadt 288: }
289:
1.65 deraadt 290: /*
291: * Called from the main program after receiving SIGHUP.
292: * Restarts the server.
293: */
1.200 itojun 294: static void
1.165 itojun 295: sighup_restart(void)
1.1 deraadt 296: {
1.264 itojun 297: logit("Received SIGHUP; restarting.");
1.75 markus 298: close_listen_socks();
1.211 markus 299: close_startup_pipes();
1.349 dtucker 300: alarm(0); /* alarm timer persists across exec */
1.369 dtucker 301: signal(SIGHUP, SIG_IGN); /* will be restored after exec */
1.64 markus 302: execv(saved_argv[0], saved_argv);
1.264 itojun 303: logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
1.250 deraadt 304: strerror(errno));
1.64 markus 305: exit(1);
1.1 deraadt 306: }
307:
1.65 deraadt 308: /*
309: * Generic signal handler for terminating signals in the master daemon.
310: */
1.327 deraadt 311: /*ARGSUSED*/
1.200 itojun 312: static void
1.64 markus 313: sigterm_handler(int sig)
1.1 deraadt 314: {
1.199 markus 315: received_sigterm = sig;
1.1 deraadt 316: }
317:
1.65 deraadt 318: /*
319: * SIGCHLD handler. This is called whenever a child dies. This will then
1.199 markus 320: * reap any zombies left by exited children.
1.65 deraadt 321: */
1.327 deraadt 322: /*ARGSUSED*/
1.200 itojun 323: static void
1.64 markus 324: main_sigchld_handler(int sig)
1.1 deraadt 325: {
1.250 deraadt 326: int save_errno = errno;
1.239 markus 327: pid_t pid;
1.64 markus 328: int status;
1.60 deraadt 329:
1.239 markus 330: while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
331: (pid < 0 && errno == EINTR))
1.64 markus 332: ;
1.60 deraadt 333:
1.64 markus 334: signal(SIGCHLD, main_sigchld_handler);
335: errno = save_errno;
1.1 deraadt 336: }
337:
1.65 deraadt 338: /*
339: * Signal handler for the alarm after the login grace period has expired.
340: */
1.327 deraadt 341: /*ARGSUSED*/
1.200 itojun 342: static void
1.64 markus 343: grace_alarm_handler(int sig)
1.1 deraadt 344: {
1.285 dtucker 345: if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0)
346: kill(pmonitor->m_pid, SIGALRM);
1.394 djm 347:
348: /*
349: * Try to kill any processes that we have spawned, E.g. authorized
350: * keys command helpers.
351: */
352: if (getpgid(0) == getpid()) {
353: signal(SIGTERM, SIG_IGN);
354: killpg(0, SIGTERM);
355: }
1.285 dtucker 356:
1.64 markus 357: /* Log error and exit. */
1.346 deraadt 358: sigdie("Timeout before authentication for %s", get_remote_ipaddr());
1.62 markus 359: }
360:
1.65 deraadt 361: /*
362: * Signal handler for the key regeneration alarm. Note that this
363: * alarm only occurs in the daemon waiting for connections, and it does not
364: * do anything with the private key or random state before forking.
365: * Thus there should be no concurrency control/asynchronous execution
366: * problems.
367: */
1.200 itojun 368: static void
1.174 deraadt 369: generate_ephemeral_server_key(void)
1.134 markus 370: {
1.191 markus 371: verbose("Generating %s%d bit RSA key.",
1.185 djm 372: sensitive_data.server_key ? "new " : "", options.server_key_bits);
1.134 markus 373: if (sensitive_data.server_key != NULL)
374: key_free(sensitive_data.server_key);
1.191 markus 375: sensitive_data.server_key = key_generate(KEY_RSA1,
1.185 djm 376: options.server_key_bits);
377: verbose("RSA key generation complete.");
1.169 markus 378:
1.356 djm 379: arc4random_buf(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1.134 markus 380: }
1.147 deraadt 381:
1.327 deraadt 382: /*ARGSUSED*/
1.200 itojun 383: static void
1.64 markus 384: key_regeneration_alarm(int sig)
1.1 deraadt 385: {
1.64 markus 386: int save_errno = errno;
1.250 deraadt 387:
1.151 markus 388: signal(SIGALRM, SIG_DFL);
1.64 markus 389: errno = save_errno;
1.151 markus 390: key_do_regen = 1;
1.98 markus 391: }
392:
1.200 itojun 393: static void
1.96 markus 394: sshd_exchange_identification(int sock_in, int sock_out)
395: {
1.311 djm 396: u_int i;
397: int mismatch;
1.96 markus 398: int remote_major, remote_minor;
1.102 markus 399: int major, minor;
1.363 dtucker 400: char *s, *newline = "\n";
1.96 markus 401: char buf[256]; /* Must not be larger than remote_version. */
402: char remote_version[256]; /* Must be at least as big as buf. */
403:
1.103 markus 404: if ((options.protocol & SSH_PROTO_1) &&
405: (options.protocol & SSH_PROTO_2)) {
1.102 markus 406: major = PROTOCOL_MAJOR_1;
407: minor = 99;
408: } else if (options.protocol & SSH_PROTO_2) {
409: major = PROTOCOL_MAJOR_2;
410: minor = PROTOCOL_MINOR_2;
1.363 dtucker 411: newline = "\r\n";
1.102 markus 412: } else {
413: major = PROTOCOL_MAJOR_1;
414: minor = PROTOCOL_MINOR_1;
415: }
1.390 djm 416:
417: xasprintf(&server_version_string, "SSH-%d.%d-%.100s%s%s%s",
418: major, minor, SSH_VERSION,
419: *options.version_addendum == '\0' ? "" : " ",
420: options.version_addendum, newline);
1.96 markus 421:
1.272 markus 422: /* Send our protocol version identification. */
1.367 andreas 423: if (roaming_atomicio(vwrite, sock_out, server_version_string,
1.272 markus 424: strlen(server_version_string))
425: != strlen(server_version_string)) {
426: logit("Could not write ident string to %s", get_remote_ipaddr());
1.278 markus 427: cleanup_exit(255);
1.272 markus 428: }
429:
430: /* Read other sides version identification. */
431: memset(buf, 0, sizeof(buf));
432: for (i = 0; i < sizeof(buf) - 1; i++) {
1.367 andreas 433: if (roaming_atomicio(read, sock_in, &buf[i], 1) != 1) {
1.272 markus 434: logit("Did not receive identification string from %s",
435: get_remote_ipaddr());
1.278 markus 436: cleanup_exit(255);
1.96 markus 437: }
1.272 markus 438: if (buf[i] == '\r') {
439: buf[i] = 0;
440: /* Kludge for F-Secure Macintosh < 1.0.2 */
441: if (i == 12 &&
442: strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
1.96 markus 443: break;
1.272 markus 444: continue;
445: }
446: if (buf[i] == '\n') {
447: buf[i] = 0;
448: break;
1.96 markus 449: }
450: }
1.272 markus 451: buf[sizeof(buf) - 1] = 0;
452: client_version_string = xstrdup(buf);
1.96 markus 453:
454: /*
455: * Check that the versions match. In future this might accept
456: * several versions and set appropriate flags to handle them.
457: */
458: if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
459: &remote_major, &remote_minor, remote_version) != 3) {
1.105 markus 460: s = "Protocol mismatch.\n";
1.271 deraadt 461: (void) atomicio(vwrite, sock_out, s, strlen(s));
1.408 djm 462: logit("Bad protocol version identification '%.100s' "
463: "from %s port %d", client_version_string,
464: get_remote_ipaddr(), get_remote_port());
1.411 djm 465: close(sock_in);
466: close(sock_out);
1.278 markus 467: cleanup_exit(255);
1.96 markus 468: }
469: debug("Client protocol version %d.%d; client software version %.100s",
1.217 deraadt 470: remote_major, remote_minor, remote_version);
1.96 markus 471:
1.98 markus 472: compat_datafellows(remote_version);
1.260 mickey 473:
1.413 djm 474: if ((datafellows & SSH_BUG_PROBE) != 0) {
1.264 itojun 475: logit("probed from %s with %s. Don't panic.",
1.260 mickey 476: get_remote_ipaddr(), client_version_string);
1.278 markus 477: cleanup_exit(255);
1.260 mickey 478: }
1.413 djm 479: if ((datafellows & SSH_BUG_SCANNER) != 0) {
1.264 itojun 480: logit("scanned from %s with %s. Don't panic.",
1.175 deraadt 481: get_remote_ipaddr(), client_version_string);
1.278 markus 482: cleanup_exit(255);
1.175 deraadt 483: }
1.414 ! djm 484: if ((datafellows & SSH_BUG_RSASIGMD5) != 0) {
1.413 djm 485: logit("Client version \"%.100s\" uses unsafe RSA signature "
486: "scheme; disabling use of RSA keys", remote_version);
1.414 ! djm 487: }
! 488: if ((datafellows & SSH_BUG_DERIVEKEY) != 0) {
! 489: fatal("Client version \"%.100s\" uses unsafe key agreement; "
! 490: "refusing connection", remote_version);
! 491: }
1.98 markus 492:
1.102 markus 493: mismatch = 0;
1.214 deraadt 494: switch (remote_major) {
1.96 markus 495: case 1:
1.108 markus 496: if (remote_minor == 99) {
497: if (options.protocol & SSH_PROTO_2)
498: enable_compat20();
499: else
500: mismatch = 1;
501: break;
502: }
1.102 markus 503: if (!(options.protocol & SSH_PROTO_1)) {
504: mismatch = 1;
505: break;
506: }
1.96 markus 507: if (remote_minor < 3) {
1.121 provos 508: packet_disconnect("Your ssh version is too old and "
1.96 markus 509: "is no longer supported. Please install a newer version.");
510: } else if (remote_minor == 3) {
511: /* note that this disables agent-forwarding */
512: enable_compat13();
513: }
1.102 markus 514: break;
1.98 markus 515: case 2:
1.102 markus 516: if (options.protocol & SSH_PROTO_2) {
1.98 markus 517: enable_compat20();
518: break;
519: }
1.99 markus 520: /* FALLTHROUGH */
1.105 markus 521: default:
1.102 markus 522: mismatch = 1;
523: break;
524: }
525: chop(server_version_string);
526: debug("Local version string %.200s", server_version_string);
527:
528: if (mismatch) {
1.96 markus 529: s = "Protocol major versions differ.\n";
1.271 deraadt 530: (void) atomicio(vwrite, sock_out, s, strlen(s));
1.96 markus 531: close(sock_in);
532: close(sock_out);
1.264 itojun 533: logit("Protocol major versions differ for %s: %.200s vs. %.200s",
1.102 markus 534: get_remote_ipaddr(),
535: server_version_string, client_version_string);
1.278 markus 536: cleanup_exit(255);
1.96 markus 537: }
1.108 markus 538: }
539:
1.134 markus 540: /* Destroy the host and server keys. They will no longer be needed. */
1.108 markus 541: void
542: destroy_sensitive_data(void)
543: {
1.134 markus 544: int i;
545:
546: if (sensitive_data.server_key) {
547: key_free(sensitive_data.server_key);
548: sensitive_data.server_key = NULL;
549: }
1.217 deraadt 550: for (i = 0; i < options.num_host_key_files; i++) {
1.134 markus 551: if (sensitive_data.host_keys[i]) {
552: key_free(sensitive_data.host_keys[i]);
553: sensitive_data.host_keys[i] = NULL;
554: }
1.373 djm 555: if (sensitive_data.host_certificates[i]) {
556: key_free(sensitive_data.host_certificates[i]);
557: sensitive_data.host_certificates[i] = NULL;
558: }
1.134 markus 559: }
560: sensitive_data.ssh1_host_key = NULL;
1.169 markus 561: memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH);
1.134 markus 562: }
563:
1.231 provos 564: /* Demote private to public keys for network child */
565: void
566: demote_sensitive_data(void)
567: {
568: Key *tmp;
569: int i;
570:
571: if (sensitive_data.server_key) {
572: tmp = key_demote(sensitive_data.server_key);
573: key_free(sensitive_data.server_key);
574: sensitive_data.server_key = tmp;
575: }
576:
577: for (i = 0; i < options.num_host_key_files; i++) {
578: if (sensitive_data.host_keys[i]) {
579: tmp = key_demote(sensitive_data.host_keys[i]);
580: key_free(sensitive_data.host_keys[i]);
581: sensitive_data.host_keys[i] = tmp;
582: if (tmp->type == KEY_RSA1)
583: sensitive_data.ssh1_host_key = tmp;
584: }
1.373 djm 585: /* Certs do not need demotion */
1.231 provos 586: }
587:
588: /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */
589: }
590:
1.233 markus 591: static void
1.231 provos 592: privsep_preauth_child(void)
593: {
1.254 deraadt 594: u_int32_t rnd[256];
1.253 deraadt 595: gid_t gidset[1];
1.250 deraadt 596: struct passwd *pw;
1.231 provos 597:
598: /* Enable challenge-response authentication for privilege separation */
599: privsep_challenge_enable();
600:
1.356 djm 601: arc4random_buf(rnd, sizeof(rnd));
1.254 deraadt 602: RAND_seed(rnd, sizeof(rnd));
1.405 djm 603: bzero(rnd, sizeof(rnd));
1.231 provos 604:
605: /* Demote the private keys to public keys. */
606: demote_sensitive_data();
607:
1.235 stevesk 608: if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
1.240 djm 609: fatal("Privilege separation user %s does not exist",
610: SSH_PRIVSEP_USER);
1.235 stevesk 611: memset(pw->pw_passwd, 0, strlen(pw->pw_passwd));
612: endpwent();
613:
1.255 deraadt 614: /* Change our root directory */
1.232 stevesk 615: if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
616: fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
617: strerror(errno));
1.231 provos 618: if (chdir("/") == -1)
1.236 stevesk 619: fatal("chdir(\"/\"): %s", strerror(errno));
1.234 markus 620:
1.231 provos 621: /* Drop our privileges */
1.235 stevesk 622: debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
623: (u_int)pw->pw_gid);
1.251 markus 624: #if 0
1.287 djm 625: /* XXX not ready, too heavy after chroot */
1.235 stevesk 626: do_setusercontext(pw);
1.251 markus 627: #else
628: gidset[0] = pw->pw_gid;
629: if (setgroups(1, gidset) < 0)
630: fatal("setgroups: %.100s", strerror(errno));
631: permanently_set_uid(pw);
632: #endif
1.231 provos 633: }
634:
1.278 markus 635: static int
636: privsep_preauth(Authctxt *authctxt)
1.237 markus 637: {
638: int status;
639: pid_t pid;
1.384 djm 640: struct ssh_sandbox *box = NULL;
1.237 markus 641:
642: /* Set up unprivileged child process to deal with network data */
1.242 mouring 643: pmonitor = monitor_init();
1.237 markus 644: /* Store a pointer to the kex for later rekeying */
1.242 mouring 645: pmonitor->m_pkex = &xxx_kex;
1.237 markus 646:
1.393 djm 647: if (use_privsep == PRIVSEP_ON)
1.384 djm 648: box = ssh_sandbox_init();
1.237 markus 649: pid = fork();
650: if (pid == -1) {
651: fatal("fork of unprivileged child failed");
652: } else if (pid != 0) {
1.245 mpech 653: debug2("Network child is on pid %ld", (long)pid);
1.237 markus 654:
1.392 markus 655: pmonitor->m_pid = pid;
1.404 markus 656: if (have_agent)
657: auth_conn = ssh_get_authentication_connection();
1.384 djm 658: if (box != NULL)
659: ssh_sandbox_parent_preauth(box, pid);
1.278 markus 660: monitor_child_preauth(authctxt, pmonitor);
1.237 markus 661:
662: /* Sync memory */
1.242 mouring 663: monitor_sync(pmonitor);
1.237 markus 664:
665: /* Wait for the child's exit status */
1.384 djm 666: while (waitpid(pid, &status, 0) < 0) {
1.386 djm 667: if (errno == EINTR)
668: continue;
669: pmonitor->m_pid = -1;
670: fatal("%s: waitpid: %s", __func__, strerror(errno));
1.384 djm 671: }
1.386 djm 672: privsep_is_preauth = 0;
673: pmonitor->m_pid = -1;
1.384 djm 674: if (WIFEXITED(status)) {
675: if (WEXITSTATUS(status) != 0)
676: fatal("%s: preauth child exited with status %d",
677: __func__, WEXITSTATUS(status));
678: } else if (WIFSIGNALED(status))
679: fatal("%s: preauth child terminated by signal %d",
680: __func__, WTERMSIG(status));
681: if (box != NULL)
682: ssh_sandbox_parent_finish(box);
683: return 1;
1.237 markus 684: } else {
685: /* child */
1.383 djm 686: close(pmonitor->m_sendfd);
687: close(pmonitor->m_log_recvfd);
1.237 markus 688:
1.383 djm 689: /* Arrange for logging to be sent to the monitor */
690: set_log_handler(mm_log_handler, pmonitor);
1.237 markus 691:
692: /* Demote the child */
693: if (getuid() == 0 || geteuid() == 0)
694: privsep_preauth_child();
1.238 stevesk 695: setproctitle("%s", "[net]");
1.384 djm 696: if (box != NULL)
697: ssh_sandbox_child(box);
698:
699: return 0;
1.237 markus 700: }
701: }
702:
1.233 markus 703: static void
1.237 markus 704: privsep_postauth(Authctxt *authctxt)
1.231 provos 705: {
1.354 djm 706: u_int32_t rnd[256];
707:
1.231 provos 708: if (authctxt->pw->pw_uid == 0 || options.use_login) {
709: /* File descriptor passing is broken or root login */
710: use_privsep = 0;
1.315 djm 711: goto skip;
1.231 provos 712: }
1.234 markus 713:
1.231 provos 714: /* New socket pair */
1.242 mouring 715: monitor_reinit(pmonitor);
1.231 provos 716:
1.242 mouring 717: pmonitor->m_pid = fork();
718: if (pmonitor->m_pid == -1)
1.231 provos 719: fatal("fork of unprivileged child failed");
1.242 mouring 720: else if (pmonitor->m_pid != 0) {
1.364 markus 721: verbose("User child is on pid %ld", (long)pmonitor->m_pid);
1.307 otto 722: buffer_clear(&loginmsg);
1.242 mouring 723: monitor_child_postauth(pmonitor);
1.231 provos 724:
725: /* NEVERREACHED */
726: exit(0);
727: }
728:
1.383 djm 729: /* child */
730:
1.242 mouring 731: close(pmonitor->m_sendfd);
1.383 djm 732: pmonitor->m_sendfd = -1;
1.231 provos 733:
734: /* Demote the private keys to public keys. */
735: demote_sensitive_data();
1.354 djm 736:
1.356 djm 737: arc4random_buf(rnd, sizeof(rnd));
1.354 djm 738: RAND_seed(rnd, sizeof(rnd));
1.405 djm 739: bzero(rnd, sizeof(rnd));
1.231 provos 740:
741: /* Drop privileges */
742: do_setusercontext(authctxt->pw);
743:
1.315 djm 744: skip:
1.231 provos 745: /* It is safe now to apply the key state */
1.242 mouring 746: monitor_apply_keystate(pmonitor);
1.312 markus 747:
748: /*
749: * Tell the packet layer that authentication was successful, since
750: * this information is not part of the key state.
751: */
752: packet_set_authenticated();
1.231 provos 753: }
754:
1.200 itojun 755: static char *
1.134 markus 756: list_hostkey_types(void)
757: {
1.223 markus 758: Buffer b;
1.281 jakob 759: const char *p;
760: char *ret;
1.134 markus 761: int i;
1.373 djm 762: Key *key;
1.223 markus 763:
764: buffer_init(&b);
1.217 deraadt 765: for (i = 0; i < options.num_host_key_files; i++) {
1.373 djm 766: key = sensitive_data.host_keys[i];
1.134 markus 767: if (key == NULL)
1.404 markus 768: key = sensitive_data.host_pubkeys[i];
769: if (key == NULL)
1.134 markus 770: continue;
1.214 deraadt 771: switch (key->type) {
1.134 markus 772: case KEY_RSA:
773: case KEY_DSA:
1.378 djm 774: case KEY_ECDSA:
1.412 markus 775: case KEY_ED25519:
1.223 markus 776: if (buffer_len(&b) > 0)
777: buffer_append(&b, ",", 1);
778: p = key_ssh_name(key);
779: buffer_append(&b, p, strlen(p));
1.134 markus 780: break;
781: }
1.373 djm 782: /* If the private key has a cert peer, then list that too */
783: key = sensitive_data.host_certificates[i];
784: if (key == NULL)
785: continue;
786: switch (key->type) {
1.375 djm 787: case KEY_RSA_CERT_V00:
788: case KEY_DSA_CERT_V00:
1.373 djm 789: case KEY_RSA_CERT:
790: case KEY_DSA_CERT:
1.378 djm 791: case KEY_ECDSA_CERT:
1.412 markus 792: case KEY_ED25519_CERT:
1.373 djm 793: if (buffer_len(&b) > 0)
794: buffer_append(&b, ",", 1);
795: p = key_ssh_name(key);
796: buffer_append(&b, p, strlen(p));
797: break;
798: }
1.134 markus 799: }
1.223 markus 800: buffer_append(&b, "\0", 1);
1.281 jakob 801: ret = xstrdup(buffer_ptr(&b));
1.223 markus 802: buffer_free(&b);
1.281 jakob 803: debug("list_hostkey_types: %s", ret);
804: return ret;
1.134 markus 805: }
806:
1.373 djm 807: static Key *
808: get_hostkey_by_type(int type, int need_private)
1.134 markus 809: {
810: int i;
1.373 djm 811: Key *key;
1.250 deraadt 812:
1.217 deraadt 813: for (i = 0; i < options.num_host_key_files; i++) {
1.375 djm 814: switch (type) {
815: case KEY_RSA_CERT_V00:
816: case KEY_DSA_CERT_V00:
817: case KEY_RSA_CERT:
818: case KEY_DSA_CERT:
1.378 djm 819: case KEY_ECDSA_CERT:
1.412 markus 820: case KEY_ED25519_CERT:
1.373 djm 821: key = sensitive_data.host_certificates[i];
1.375 djm 822: break;
823: default:
1.373 djm 824: key = sensitive_data.host_keys[i];
1.404 markus 825: if (key == NULL && !need_private)
826: key = sensitive_data.host_pubkeys[i];
1.375 djm 827: break;
828: }
1.134 markus 829: if (key != NULL && key->type == type)
1.373 djm 830: return need_private ?
831: sensitive_data.host_keys[i] : key;
1.134 markus 832: }
833: return NULL;
1.96 markus 834: }
835:
1.231 provos 836: Key *
1.373 djm 837: get_hostkey_public_by_type(int type)
838: {
839: return get_hostkey_by_type(type, 0);
840: }
841:
842: Key *
843: get_hostkey_private_by_type(int type)
844: {
845: return get_hostkey_by_type(type, 1);
846: }
847:
848: Key *
1.231 provos 849: get_hostkey_by_index(int ind)
850: {
851: if (ind < 0 || ind >= options.num_host_key_files)
852: return (NULL);
853: return (sensitive_data.host_keys[ind]);
854: }
855:
1.404 markus 856: Key *
857: get_hostkey_public_by_index(int ind)
858: {
859: if (ind < 0 || ind >= options.num_host_key_files)
860: return (NULL);
861: return (sensitive_data.host_pubkeys[ind]);
862: }
863:
1.231 provos 864: int
865: get_hostkey_index(Key *key)
866: {
867: int i;
1.250 deraadt 868:
1.231 provos 869: for (i = 0; i < options.num_host_key_files; i++) {
1.373 djm 870: if (key_is_cert(key)) {
871: if (key == sensitive_data.host_certificates[i])
872: return (i);
873: } else {
874: if (key == sensitive_data.host_keys[i])
875: return (i);
1.404 markus 876: if (key == sensitive_data.host_pubkeys[i])
877: return (i);
1.373 djm 878: }
1.231 provos 879: }
880: return (-1);
881: }
882:
1.124 markus 883: /*
884: * returns 1 if connection should be dropped, 0 otherwise.
885: * dropping starts at connection #max_startups_begin with a probability
886: * of (max_startups_rate/100). the probability increases linearly until
887: * all connections are dropped for startups > max_startups
888: */
1.200 itojun 889: static int
1.124 markus 890: drop_connection(int startups)
891: {
1.303 mickey 892: int p, r;
1.124 markus 893:
894: if (startups < options.max_startups_begin)
895: return 0;
896: if (startups >= options.max_startups)
897: return 1;
898: if (options.max_startups_rate == 100)
899: return 1;
900:
901: p = 100 - options.max_startups_rate;
902: p *= startups - options.max_startups_begin;
1.303 mickey 903: p /= options.max_startups - options.max_startups_begin;
1.124 markus 904: p += options.max_startups_rate;
1.356 djm 905: r = arc4random_uniform(100);
1.124 markus 906:
1.304 djm 907: debug("drop_connection: p %d, r %d", p, r);
1.124 markus 908: return (r < p) ? 1 : 0;
909: }
910:
1.215 markus 911: static void
912: usage(void)
913: {
1.290 markus 914: fprintf(stderr, "%s, %s\n",
1.280 markus 915: SSH_VERSION, SSLeay_version(SSLEAY_VERSION));
1.289 markus 916: fprintf(stderr,
1.373 djm 917: "usage: sshd [-46DdeiqTt] [-b bits] [-C connection_spec] [-c host_cert_file]\n"
1.399 dtucker 918: " [-E log_file] [-f config_file] [-g login_grace_time]\n"
919: " [-h host_key_file] [-k key_gen_time] [-o option] [-p port]\n"
920: " [-u len]\n"
1.289 markus 921: );
1.215 markus 922: exit(1);
923: }
924:
1.294 djm 925: static void
926: send_rexec_state(int fd, Buffer *conf)
927: {
928: Buffer m;
929:
930: debug3("%s: entering fd = %d config len %d", __func__, fd,
931: buffer_len(conf));
932:
933: /*
934: * Protocol from reexec master to child:
935: * string configuration
936: * u_int ephemeral_key_follows
937: * bignum e (only if ephemeral_key_follows == 1)
938: * bignum n "
939: * bignum d "
940: * bignum iqmp "
941: * bignum p "
942: * bignum q "
943: */
944: buffer_init(&m);
945: buffer_put_cstring(&m, buffer_ptr(conf));
946:
1.298 deraadt 947: if (sensitive_data.server_key != NULL &&
1.294 djm 948: sensitive_data.server_key->type == KEY_RSA1) {
949: buffer_put_int(&m, 1);
950: buffer_put_bignum(&m, sensitive_data.server_key->rsa->e);
951: buffer_put_bignum(&m, sensitive_data.server_key->rsa->n);
952: buffer_put_bignum(&m, sensitive_data.server_key->rsa->d);
953: buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp);
954: buffer_put_bignum(&m, sensitive_data.server_key->rsa->p);
955: buffer_put_bignum(&m, sensitive_data.server_key->rsa->q);
956: } else
957: buffer_put_int(&m, 0);
958:
959: if (ssh_msg_send(fd, 0, &m) == -1)
960: fatal("%s: ssh_msg_send failed", __func__);
961:
962: buffer_free(&m);
963:
964: debug3("%s: done", __func__);
965: }
966:
967: static void
968: recv_rexec_state(int fd, Buffer *conf)
969: {
970: Buffer m;
971: char *cp;
972: u_int len;
973:
974: debug3("%s: entering fd = %d", __func__, fd);
975:
976: buffer_init(&m);
977:
978: if (ssh_msg_recv(fd, &m) == -1)
979: fatal("%s: ssh_msg_recv failed", __func__);
980: if (buffer_get_char(&m) != 0)
981: fatal("%s: rexec version mismatch", __func__);
982:
983: cp = buffer_get_string(&m, &len);
984: if (conf != NULL)
985: buffer_append(conf, cp, len + 1);
1.402 djm 986: free(cp);
1.294 djm 987:
988: if (buffer_get_int(&m)) {
989: if (sensitive_data.server_key != NULL)
990: key_free(sensitive_data.server_key);
991: sensitive_data.server_key = key_new_private(KEY_RSA1);
992: buffer_get_bignum(&m, sensitive_data.server_key->rsa->e);
993: buffer_get_bignum(&m, sensitive_data.server_key->rsa->n);
994: buffer_get_bignum(&m, sensitive_data.server_key->rsa->d);
995: buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp);
996: buffer_get_bignum(&m, sensitive_data.server_key->rsa->p);
997: buffer_get_bignum(&m, sensitive_data.server_key->rsa->q);
998: rsa_generate_additional_parameters(
999: sensitive_data.server_key->rsa);
1000: }
1001: buffer_free(&m);
1002:
1003: debug3("%s: done", __func__);
1004: }
1005:
1.345 djm 1006: /* Accept a connection from inetd */
1007: static void
1008: server_accept_inetd(int *sock_in, int *sock_out)
1009: {
1010: int fd;
1011:
1012: startup_pipe = -1;
1013: if (rexeced_flag) {
1014: close(REEXEC_CONFIG_PASS_FD);
1015: *sock_in = *sock_out = dup(STDIN_FILENO);
1016: if (!debug_flag) {
1017: startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
1018: close(REEXEC_STARTUP_PIPE_FD);
1019: }
1020: } else {
1021: *sock_in = dup(STDIN_FILENO);
1022: *sock_out = dup(STDOUT_FILENO);
1023: }
1024: /*
1025: * We intentionally do not close the descriptors 0, 1, and 2
1026: * as our code for setting the descriptors won't work if
1027: * ttyfd happens to be one of those.
1028: */
1029: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1030: dup2(fd, STDIN_FILENO);
1031: dup2(fd, STDOUT_FILENO);
1.403 dtucker 1032: if (!log_stderr)
1033: dup2(fd, STDERR_FILENO);
1034: if (fd > (log_stderr ? STDERR_FILENO : STDOUT_FILENO))
1.345 djm 1035: close(fd);
1036: }
1037: debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out);
1038: }
1039:
1040: /*
1041: * Listen for TCP connections
1042: */
1043: static void
1044: server_listen(void)
1045: {
1046: int ret, listen_sock, on = 1;
1047: struct addrinfo *ai;
1048: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1049:
1050: for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
1051: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1052: continue;
1053: if (num_listen_socks >= MAX_LISTEN_SOCKS)
1054: fatal("Too many listen sockets. "
1055: "Enlarge MAX_LISTEN_SOCKS");
1056: if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
1057: ntop, sizeof(ntop), strport, sizeof(strport),
1058: NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
1059: error("getnameinfo failed: %.100s",
1.352 dtucker 1060: ssh_gai_strerror(ret));
1.345 djm 1061: continue;
1062: }
1063: /* Create socket for listening. */
1.370 dtucker 1064: listen_sock = socket(ai->ai_family, ai->ai_socktype,
1065: ai->ai_protocol);
1.345 djm 1066: if (listen_sock < 0) {
1067: /* kernel may not support ipv6 */
1068: verbose("socket: %.100s", strerror(errno));
1069: continue;
1070: }
1071: if (set_nonblock(listen_sock) == -1) {
1072: close(listen_sock);
1073: continue;
1074: }
1075: /*
1076: * Set socket options.
1077: * Allow local port reuse in TIME_WAIT.
1078: */
1079: if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
1080: &on, sizeof(on)) == -1)
1081: error("setsockopt SO_REUSEADDR: %s", strerror(errno));
1082:
1083: debug("Bind to port %s on %s.", strport, ntop);
1084:
1085: /* Bind the socket to the desired port. */
1086: if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1087: error("Bind to port %s on %s failed: %.200s.",
1088: strport, ntop, strerror(errno));
1089: close(listen_sock);
1090: continue;
1091: }
1092: listen_socks[num_listen_socks] = listen_sock;
1093: num_listen_socks++;
1094:
1095: /* Start listening on the port. */
1096: if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
1097: fatal("listen on [%s]:%s: %.100s",
1098: ntop, strport, strerror(errno));
1099: logit("Server listening on %s port %s.", ntop, strport);
1100: }
1101: freeaddrinfo(options.listen_addrs);
1102:
1103: if (!num_listen_socks)
1104: fatal("Cannot bind any address.");
1105: }
1106:
1107: /*
1108: * The main TCP accept loop. Note that, for the non-debug case, returns
1109: * from this function are in a forked subprocess.
1110: */
1111: static void
1112: server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
1113: {
1114: fd_set *fdset;
1115: int i, j, ret, maxfd;
1116: int key_used = 0, startups = 0;
1117: int startup_p[2] = { -1 , -1 };
1118: struct sockaddr_storage from;
1119: socklen_t fromlen;
1120: pid_t pid;
1.405 djm 1121: u_char rnd[256];
1.345 djm 1122:
1123: /* setup fd set for accept */
1124: fdset = NULL;
1125: maxfd = 0;
1126: for (i = 0; i < num_listen_socks; i++)
1127: if (listen_socks[i] > maxfd)
1128: maxfd = listen_socks[i];
1129: /* pipes connected to unauthenticated childs */
1130: startup_pipes = xcalloc(options.max_startups, sizeof(int));
1131: for (i = 0; i < options.max_startups; i++)
1132: startup_pipes[i] = -1;
1133:
1134: /*
1135: * Stay listening for connections until the system crashes or
1136: * the daemon is killed with a signal.
1137: */
1138: for (;;) {
1139: if (received_sighup)
1140: sighup_restart();
1141: if (fdset != NULL)
1.402 djm 1142: free(fdset);
1.345 djm 1143: fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS),
1144: sizeof(fd_mask));
1145:
1146: for (i = 0; i < num_listen_socks; i++)
1147: FD_SET(listen_socks[i], fdset);
1148: for (i = 0; i < options.max_startups; i++)
1149: if (startup_pipes[i] != -1)
1150: FD_SET(startup_pipes[i], fdset);
1151:
1152: /* Wait in select until there is a connection. */
1153: ret = select(maxfd+1, fdset, NULL, NULL, NULL);
1154: if (ret < 0 && errno != EINTR)
1155: error("select: %.100s", strerror(errno));
1156: if (received_sigterm) {
1157: logit("Received signal %d; terminating.",
1158: (int) received_sigterm);
1159: close_listen_socks();
1160: unlink(options.pid_file);
1.382 djm 1161: exit(received_sigterm == SIGTERM ? 0 : 255);
1.345 djm 1162: }
1163: if (key_used && key_do_regen) {
1164: generate_ephemeral_server_key();
1165: key_used = 0;
1166: key_do_regen = 0;
1167: }
1168: if (ret < 0)
1169: continue;
1170:
1171: for (i = 0; i < options.max_startups; i++)
1172: if (startup_pipes[i] != -1 &&
1173: FD_ISSET(startup_pipes[i], fdset)) {
1174: /*
1175: * the read end of the pipe is ready
1176: * if the child has closed the pipe
1177: * after successful authentication
1178: * or if the child has died
1179: */
1180: close(startup_pipes[i]);
1181: startup_pipes[i] = -1;
1182: startups--;
1183: }
1184: for (i = 0; i < num_listen_socks; i++) {
1185: if (!FD_ISSET(listen_socks[i], fdset))
1186: continue;
1187: fromlen = sizeof(from);
1188: *newsock = accept(listen_socks[i],
1189: (struct sockaddr *)&from, &fromlen);
1190: if (*newsock < 0) {
1.398 markus 1191: if (errno != EINTR && errno != EWOULDBLOCK &&
1192: errno != ECONNABORTED)
1.389 djm 1193: error("accept: %.100s",
1194: strerror(errno));
1195: if (errno == EMFILE || errno == ENFILE)
1196: usleep(100 * 1000);
1.345 djm 1197: continue;
1198: }
1199: if (unset_nonblock(*newsock) == -1) {
1200: close(*newsock);
1201: continue;
1202: }
1203: if (drop_connection(startups) == 1) {
1204: debug("drop connection #%d", startups);
1205: close(*newsock);
1206: continue;
1207: }
1208: if (pipe(startup_p) == -1) {
1209: close(*newsock);
1210: continue;
1211: }
1212:
1213: if (rexec_flag && socketpair(AF_UNIX,
1214: SOCK_STREAM, 0, config_s) == -1) {
1215: error("reexec socketpair: %s",
1216: strerror(errno));
1217: close(*newsock);
1218: close(startup_p[0]);
1219: close(startup_p[1]);
1220: continue;
1221: }
1222:
1223: for (j = 0; j < options.max_startups; j++)
1224: if (startup_pipes[j] == -1) {
1225: startup_pipes[j] = startup_p[0];
1226: if (maxfd < startup_p[0])
1227: maxfd = startup_p[0];
1228: startups++;
1229: break;
1230: }
1231:
1232: /*
1233: * Got connection. Fork a child to handle it, unless
1234: * we are in debugging mode.
1235: */
1236: if (debug_flag) {
1237: /*
1238: * In debugging mode. Close the listening
1239: * socket, and start processing the
1240: * connection without forking.
1241: */
1242: debug("Server will not fork when running in debugging mode.");
1243: close_listen_socks();
1244: *sock_in = *newsock;
1245: *sock_out = *newsock;
1246: close(startup_p[0]);
1247: close(startup_p[1]);
1248: startup_pipe = -1;
1249: pid = getpid();
1250: if (rexec_flag) {
1251: send_rexec_state(config_s[0],
1252: &cfg);
1253: close(config_s[0]);
1254: }
1255: break;
1256: }
1257:
1258: /*
1259: * Normal production daemon. Fork, and have
1260: * the child process the connection. The
1261: * parent continues listening.
1262: */
1263: if ((pid = fork()) == 0) {
1264: /*
1265: * Child. Close the listening and
1266: * max_startup sockets. Start using
1267: * the accepted socket. Reinitialize
1268: * logging (since our pid has changed).
1269: * We break out of the loop to handle
1270: * the connection.
1271: */
1272: startup_pipe = startup_p[1];
1273: close_startup_pipes();
1274: close_listen_socks();
1275: *sock_in = *newsock;
1276: *sock_out = *newsock;
1277: log_init(__progname,
1278: options.log_level,
1279: options.log_facility,
1280: log_stderr);
1281: if (rexec_flag)
1282: close(config_s[0]);
1283: break;
1284: }
1285:
1286: /* Parent. Stay in the loop. */
1287: if (pid < 0)
1288: error("fork: %.100s", strerror(errno));
1289: else
1290: debug("Forked child %ld.", (long)pid);
1291:
1292: close(startup_p[1]);
1293:
1294: if (rexec_flag) {
1295: send_rexec_state(config_s[0], &cfg);
1296: close(config_s[0]);
1297: close(config_s[1]);
1298: }
1299:
1300: /*
1301: * Mark that the key has been used (it
1302: * was "given" to the child).
1303: */
1304: if ((options.protocol & SSH_PROTO_1) &&
1305: key_used == 0) {
1306: /* Schedule server key regeneration alarm. */
1307: signal(SIGALRM, key_regeneration_alarm);
1308: alarm(options.key_regeneration_time);
1309: key_used = 1;
1310: }
1311:
1312: close(*newsock);
1313:
1314: /*
1315: * Ensure that our random state differs
1316: * from that of the child
1317: */
1.405 djm 1318: arc4random_buf(rnd, sizeof(rnd));
1319: RAND_seed(rnd, sizeof(rnd));
1320: bzero(rnd, sizeof(rnd));
1.345 djm 1321: }
1322:
1323: /* child process check (or debug mode) */
1324: if (num_listen_socks < 0)
1325: break;
1326: }
1327: }
1328:
1329:
1.65 deraadt 1330: /*
1331: * Main program for the daemon.
1332: */
1.2 provos 1333: int
1334: main(int ac, char **av)
1.1 deraadt 1335: {
1.64 markus 1336: extern char *optarg;
1337: extern int optind;
1.373 djm 1338: int opt, i, j, on = 1;
1.297 avsm 1339: int sock_in = -1, sock_out = -1, newsock = -1;
1.64 markus 1340: const char *remote_ip;
1341: int remote_port;
1.399 dtucker 1342: char *line, *logfile = NULL;
1.345 djm 1343: int config_s[2] = { -1 , -1 };
1.396 djm 1344: u_int n;
1.364 markus 1345: u_int64_t ibytes, obytes;
1.362 dtucker 1346: mode_t new_umask;
1.278 markus 1347: Key *key;
1.404 markus 1348: Key *pubkey;
1349: int keytype;
1.230 provos 1350: Authctxt *authctxt;
1.391 dtucker 1351: struct connection_info *connection_info = get_connection_info(0, 0);
1.64 markus 1352:
1.138 markus 1353: /* Save argv. */
1.64 markus 1354: saved_argv = av;
1.294 djm 1355: rexec_argc = ac;
1.313 djm 1356:
1357: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1358: sanitise_stdfd();
1.64 markus 1359:
1360: /* Initialize configuration options to their default values. */
1361: initialize_server_options(&options);
1362:
1363: /* Parse command-line arguments. */
1.399 dtucker 1364: while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:C:dDeE:iqrtQRT46")) != -1) {
1.64 markus 1365: switch (opt) {
1.75 markus 1366: case '4':
1.305 djm 1367: options.address_family = AF_INET;
1.75 markus 1368: break;
1369: case '6':
1.305 djm 1370: options.address_family = AF_INET6;
1.75 markus 1371: break;
1.64 markus 1372: case 'f':
1373: config_file_name = optarg;
1374: break;
1.373 djm 1375: case 'c':
1376: if (options.num_host_cert_files >= MAX_HOSTCERTS) {
1377: fprintf(stderr, "too many host certificates.\n");
1378: exit(1);
1379: }
1380: options.host_cert_files[options.num_host_cert_files++] =
1381: derelativise_path(optarg);
1382: break;
1.64 markus 1383: case 'd':
1.273 markus 1384: if (debug_flag == 0) {
1.127 markus 1385: debug_flag = 1;
1386: options.log_level = SYSLOG_LEVEL_DEBUG1;
1.273 markus 1387: } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
1.127 markus 1388: options.log_level++;
1.64 markus 1389: break;
1.135 markus 1390: case 'D':
1391: no_daemon_flag = 1;
1.192 lebel 1392: break;
1.399 dtucker 1393: case 'E':
1394: logfile = xstrdup(optarg);
1395: /* FALLTHROUGH */
1.192 lebel 1396: case 'e':
1397: log_stderr = 1;
1.135 markus 1398: break;
1.64 markus 1399: case 'i':
1400: inetd_flag = 1;
1401: break;
1.294 djm 1402: case 'r':
1403: rexec_flag = 0;
1404: break;
1405: case 'R':
1406: rexeced_flag = 1;
1407: inetd_flag = 1;
1408: break;
1.64 markus 1409: case 'Q':
1.158 markus 1410: /* ignored */
1.64 markus 1411: break;
1412: case 'q':
1413: options.log_level = SYSLOG_LEVEL_QUIET;
1414: break;
1415: case 'b':
1.327 deraadt 1416: options.server_key_bits = (int)strtonum(optarg, 256,
1417: 32768, NULL);
1.64 markus 1418: break;
1419: case 'p':
1.75 markus 1420: options.ports_from_cmdline = 1;
1.127 markus 1421: if (options.num_ports >= MAX_PORTS) {
1422: fprintf(stderr, "too many ports.\n");
1423: exit(1);
1424: }
1.193 stevesk 1425: options.ports[options.num_ports++] = a2port(optarg);
1.366 djm 1426: if (options.ports[options.num_ports-1] <= 0) {
1.193 stevesk 1427: fprintf(stderr, "Bad port number.\n");
1428: exit(1);
1429: }
1.64 markus 1430: break;
1431: case 'g':
1.197 stevesk 1432: if ((options.login_grace_time = convtime(optarg)) == -1) {
1433: fprintf(stderr, "Invalid login grace time.\n");
1434: exit(1);
1435: }
1.64 markus 1436: break;
1437: case 'k':
1.197 stevesk 1438: if ((options.key_regeneration_time = convtime(optarg)) == -1) {
1439: fprintf(stderr, "Invalid key regeneration interval.\n");
1440: exit(1);
1441: }
1.64 markus 1442: break;
1443: case 'h':
1.134 markus 1444: if (options.num_host_key_files >= MAX_HOSTKEYS) {
1445: fprintf(stderr, "too many host keys.\n");
1446: exit(1);
1447: }
1.371 djm 1448: options.host_key_files[options.num_host_key_files++] =
1449: derelativise_path(optarg);
1.64 markus 1450: break;
1.203 stevesk 1451: case 't':
1452: test_flag = 1;
1453: break;
1.358 dtucker 1454: case 'T':
1455: test_flag = 2;
1456: break;
1457: case 'C':
1.391 dtucker 1458: if (parse_server_match_testspec(connection_info,
1459: optarg) == -1)
1460: exit(1);
1.358 dtucker 1461: break;
1.125 markus 1462: case 'u':
1.327 deraadt 1463: utmp_len = (u_int)strtonum(optarg, 0, MAXHOSTNAMELEN+1, NULL);
1.257 stevesk 1464: if (utmp_len > MAXHOSTNAMELEN) {
1465: fprintf(stderr, "Invalid utmp length.\n");
1466: exit(1);
1467: }
1.125 markus 1468: break;
1.215 markus 1469: case 'o':
1.283 markus 1470: line = xstrdup(optarg);
1471: if (process_server_config_line(&options, line,
1.391 dtucker 1472: "command-line", 0, NULL, NULL) != 0)
1.217 deraadt 1473: exit(1);
1.402 djm 1474: free(line);
1.215 markus 1475: break;
1.64 markus 1476: case '?':
1477: default:
1.215 markus 1478: usage();
1479: break;
1.64 markus 1480: }
1481: }
1.294 djm 1482: if (rexeced_flag || inetd_flag)
1483: rexec_flag = 0;
1.355 mbalmer 1484: if (!test_flag && (rexec_flag && (av[0] == NULL || *av[0] != '/')))
1.294 djm 1485: fatal("sshd re-exec requires execution with an absolute path");
1486: if (rexeced_flag)
1.296 djm 1487: closefrom(REEXEC_MIN_FREE_FD);
1488: else
1489: closefrom(REEXEC_DEVCRYPTO_RESERVED_FD);
1.294 djm 1490:
1.379 djm 1491: OpenSSL_add_all_algorithms();
1.64 markus 1492:
1.399 dtucker 1493: /* If requested, redirect the logs to the specified logfile. */
1494: if (logfile != NULL) {
1495: log_redirect_stderr_to(logfile);
1.402 djm 1496: free(logfile);
1.399 dtucker 1497: }
1.75 markus 1498: /*
1499: * Force logging to stderr until we have loaded the private host
1500: * key (unless started from inetd)
1501: */
1.138 markus 1502: log_init(__progname,
1.224 markus 1503: options.log_level == SYSLOG_LEVEL_NOT_SET ?
1504: SYSLOG_LEVEL_INFO : options.log_level,
1505: options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1506: SYSLOG_FACILITY_AUTH : options.log_facility,
1.261 markus 1507: log_stderr || !inetd_flag);
1.75 markus 1508:
1.294 djm 1509: sensitive_data.server_key = NULL;
1510: sensitive_data.ssh1_host_key = NULL;
1511: sensitive_data.have_ssh1_key = 0;
1512: sensitive_data.have_ssh2_key = 0;
1513:
1.358 dtucker 1514: /*
1515: * If we're doing an extended config test, make sure we have all of
1516: * the parameters we need. If we're not doing an extended test,
1517: * do not silently ignore connection test params.
1518: */
1.391 dtucker 1519: if (test_flag >= 2 && server_match_spec_complete(connection_info) == 0)
1.358 dtucker 1520: fatal("user, host and addr are all required when testing "
1521: "Match configs");
1.391 dtucker 1522: if (test_flag < 2 && server_match_spec_complete(connection_info) >= 0)
1.358 dtucker 1523: fatal("Config test connection parameter (-C) provided without "
1524: "test mode (-T)");
1525:
1.294 djm 1526: /* Fetch our configuration */
1527: buffer_init(&cfg);
1528: if (rexeced_flag)
1.296 djm 1529: recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg);
1.294 djm 1530: else
1531: load_server_config(config_file_name, &cfg);
1532:
1.337 dtucker 1533: parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
1.391 dtucker 1534: &cfg, NULL);
1.64 markus 1535:
1536: /* Fill in default values for those options not explicitly set. */
1537: fill_default_server_options(&options);
1.350 dtucker 1538:
1539: /* challenge-response is implemented via keyboard interactive */
1540: if (options.challenge_response_authentication)
1541: options.kbd_interactive_authentication = 1;
1.395 djm 1542:
1543: /* Check that options are sensible */
1544: if (options.authorized_keys_command_user == NULL &&
1545: (options.authorized_keys_command != NULL &&
1546: strcasecmp(options.authorized_keys_command, "none") != 0))
1547: fatal("AuthorizedKeysCommand set without "
1548: "AuthorizedKeysCommandUser");
1.396 djm 1549:
1550: /*
1551: * Check whether there is any path through configured auth methods.
1552: * Unfortunately it is not possible to verify this generally before
1553: * daemonisation in the presence of Match block, but this catches
1554: * and warns for trivial misconfigurations that could break login.
1555: */
1556: if (options.num_auth_methods != 0) {
1557: if ((options.protocol & SSH_PROTO_1))
1558: fatal("AuthenticationMethods is not supported with "
1559: "SSH protocol 1");
1560: for (n = 0; n < options.num_auth_methods; n++) {
1561: if (auth2_methods_valid(options.auth_methods[n],
1562: 1) == 0)
1563: break;
1564: }
1565: if (n >= options.num_auth_methods)
1566: fatal("AuthenticationMethods cannot be satisfied by "
1567: "enabled authentication methods");
1568: }
1.305 djm 1569:
1.370 dtucker 1570: /* set default channel AF */
1.305 djm 1571: channel_set_af(options.address_family);
1.64 markus 1572:
1573: /* Check that there are no remaining arguments. */
1574: if (optind < ac) {
1575: fprintf(stderr, "Extra argument %s.\n", av[optind]);
1576: exit(1);
1577: }
1578:
1.397 dtucker 1579: debug("sshd version %s, %s", SSH_VERSION,
1580: SSLeay_version(SSLEAY_VERSION));
1.64 markus 1581:
1.404 markus 1582: /* load host keys */
1.329 djm 1583: sensitive_data.host_keys = xcalloc(options.num_host_key_files,
1.255 deraadt 1584: sizeof(Key *));
1.404 markus 1585: sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files,
1586: sizeof(Key *));
1587: for (i = 0; i < options.num_host_key_files; i++) {
1.141 markus 1588: sensitive_data.host_keys[i] = NULL;
1.404 markus 1589: sensitive_data.host_pubkeys[i] = NULL;
1590: }
1591:
1592: if (options.host_key_agent) {
1593: if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME))
1594: setenv(SSH_AUTHSOCKET_ENV_NAME,
1595: options.host_key_agent, 1);
1596: have_agent = ssh_agent_present();
1597: }
1.134 markus 1598:
1.217 deraadt 1599: for (i = 0; i < options.num_host_key_files; i++) {
1.179 markus 1600: key = key_load_private(options.host_key_files[i], "", NULL);
1.404 markus 1601: pubkey = key_load_public(options.host_key_files[i], NULL);
1.179 markus 1602: sensitive_data.host_keys[i] = key;
1.404 markus 1603: sensitive_data.host_pubkeys[i] = pubkey;
1604:
1605: if (key == NULL && pubkey != NULL && pubkey->type != KEY_RSA1 &&
1606: have_agent) {
1607: debug("will rely on agent for hostkey %s",
1608: options.host_key_files[i]);
1609: keytype = pubkey->type;
1610: } else if (key != NULL) {
1611: keytype = key->type;
1612: } else {
1.195 markus 1613: error("Could not load host key: %s",
1614: options.host_key_files[i]);
1.179 markus 1615: sensitive_data.host_keys[i] = NULL;
1.404 markus 1616: sensitive_data.host_pubkeys[i] = NULL;
1.134 markus 1617: continue;
1618: }
1.404 markus 1619:
1620: switch (keytype) {
1.134 markus 1621: case KEY_RSA1:
1622: sensitive_data.ssh1_host_key = key;
1623: sensitive_data.have_ssh1_key = 1;
1624: break;
1625: case KEY_RSA:
1626: case KEY_DSA:
1.378 djm 1627: case KEY_ECDSA:
1.412 markus 1628: case KEY_ED25519:
1.134 markus 1629: sensitive_data.have_ssh2_key = 1;
1630: break;
1631: }
1.404 markus 1632: debug("private host key: #%d type %d %s", i, keytype,
1633: key_type(key ? key : pubkey));
1.134 markus 1634: }
1635: if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
1.264 itojun 1636: logit("Disabling protocol version 1. Could not load host key");
1.108 markus 1637: options.protocol &= ~SSH_PROTO_1;
1638: }
1.134 markus 1639: if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
1.264 itojun 1640: logit("Disabling protocol version 2. Could not load host key");
1.134 markus 1641: options.protocol &= ~SSH_PROTO_2;
1.108 markus 1642: }
1.162 stevesk 1643: if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
1.264 itojun 1644: logit("sshd: no hostkeys available -- exiting.");
1.64 markus 1645: exit(1);
1646: }
1647:
1.373 djm 1648: /*
1649: * Load certificates. They are stored in an array at identical
1650: * indices to the public keys that they relate to.
1651: */
1652: sensitive_data.host_certificates = xcalloc(options.num_host_key_files,
1653: sizeof(Key *));
1654: for (i = 0; i < options.num_host_key_files; i++)
1655: sensitive_data.host_certificates[i] = NULL;
1656:
1657: for (i = 0; i < options.num_host_cert_files; i++) {
1658: key = key_load_public(options.host_cert_files[i], NULL);
1659: if (key == NULL) {
1660: error("Could not load host certificate: %s",
1661: options.host_cert_files[i]);
1662: continue;
1663: }
1664: if (!key_is_cert(key)) {
1665: error("Certificate file is not a certificate: %s",
1666: options.host_cert_files[i]);
1667: key_free(key);
1668: continue;
1669: }
1670: /* Find matching private key */
1671: for (j = 0; j < options.num_host_key_files; j++) {
1672: if (key_equal_public(key,
1673: sensitive_data.host_keys[j])) {
1674: sensitive_data.host_certificates[j] = key;
1675: break;
1676: }
1677: }
1678: if (j >= options.num_host_key_files) {
1679: error("No matching private key for certificate: %s",
1680: options.host_cert_files[i]);
1681: key_free(key);
1682: continue;
1683: }
1684: sensitive_data.host_certificates[j] = key;
1685: debug("host certificate: #%d type %d %s", j, key->type,
1686: key_type(key));
1687: }
1.108 markus 1688: /* Check certain values for sanity. */
1689: if (options.protocol & SSH_PROTO_1) {
1690: if (options.server_key_bits < 512 ||
1691: options.server_key_bits > 32768) {
1692: fprintf(stderr, "Bad server key size.\n");
1693: exit(1);
1694: }
1695: /*
1696: * Check that server and host key lengths differ sufficiently. This
1697: * is necessary to make double encryption work with rsaref. Oh, I
1698: * hate software patents. I dont know if this can go? Niels
1699: */
1700: if (options.server_key_bits >
1.250 deraadt 1701: BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
1702: SSH_KEY_BITS_RESERVED && options.server_key_bits <
1703: BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1704: SSH_KEY_BITS_RESERVED) {
1.108 markus 1705: options.server_key_bits =
1.250 deraadt 1706: BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1707: SSH_KEY_BITS_RESERVED;
1.108 markus 1708: debug("Forcing server key to %d bits to make it differ from host key.",
1709: options.server_key_bits);
1710: }
1.244 markus 1711: }
1712:
1713: if (use_privsep) {
1714: struct stat st;
1715:
1.327 deraadt 1716: if (getpwnam(SSH_PRIVSEP_USER) == NULL)
1.244 markus 1717: fatal("Privilege separation user %s does not exist",
1718: SSH_PRIVSEP_USER);
1719: if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
1720: (S_ISDIR(st.st_mode) == 0))
1721: fatal("Missing privilege separation directory: %s",
1.247 stevesk 1722: _PATH_PRIVSEP_CHROOT_DIR);
1723: if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
1.262 markus 1724: fatal("%s must be owned by root and not group or "
1725: "world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
1.358 dtucker 1726: }
1727:
1728: if (test_flag > 1) {
1.391 dtucker 1729: if (server_match_spec_complete(connection_info) == 1)
1730: parse_server_match_config(&options, connection_info);
1.358 dtucker 1731: dump_config(&options);
1.108 markus 1732: }
1.203 stevesk 1733:
1734: /* Configuration looks good, so exit if in test mode. */
1735: if (test_flag)
1736: exit(0);
1.108 markus 1737:
1.294 djm 1738: if (rexec_flag) {
1.329 djm 1739: rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *));
1.294 djm 1740: for (i = 0; i < rexec_argc; i++) {
1741: debug("rexec_argv[%d]='%s'", i, saved_argv[i]);
1742: rexec_argv[i] = saved_argv[i];
1743: }
1744: rexec_argv[rexec_argc] = "-R";
1745: rexec_argv[rexec_argc + 1] = NULL;
1746: }
1.362 dtucker 1747:
1748: /* Ensure that umask disallows at least group and world write */
1749: new_umask = umask(0077) | 0022;
1750: (void) umask(new_umask);
1.294 djm 1751:
1.108 markus 1752: /* Initialize the log (it is reinitialized below in case we forked). */
1.306 dtucker 1753: if (debug_flag && (!inetd_flag || rexeced_flag))
1.64 markus 1754: log_stderr = 1;
1.138 markus 1755: log_init(__progname, options.log_level, options.log_facility, log_stderr);
1.64 markus 1756:
1.108 markus 1757: /*
1758: * If not in debugging mode, and not started from inetd, disconnect
1759: * from the controlling terminal, and fork. The original process
1760: * exits.
1761: */
1.135 markus 1762: if (!(debug_flag || inetd_flag || no_daemon_flag)) {
1.64 markus 1763: int fd;
1.345 djm 1764:
1.64 markus 1765: if (daemon(0, 0) < 0)
1766: fatal("daemon() failed: %.200s", strerror(errno));
1767:
1768: /* Disconnect from the controlling tty. */
1.165 itojun 1769: fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
1.64 markus 1770: if (fd >= 0) {
1771: (void) ioctl(fd, TIOCNOTTY, NULL);
1772: close(fd);
1773: }
1774: }
1775: /* Reinitialize the log (because of the fork above). */
1.138 markus 1776: log_init(__progname, options.log_level, options.log_facility, log_stderr);
1.64 markus 1777:
1778: /* Chdir to the root directory so that the current disk can be
1779: unmounted if desired. */
1.401 dtucker 1780: if (chdir("/") == -1)
1781: error("chdir(\"/\"): %s", strerror(errno));
1.217 deraadt 1782:
1.178 markus 1783: /* ignore SIGPIPE */
1784: signal(SIGPIPE, SIG_IGN);
1.64 markus 1785:
1.345 djm 1786: /* Get a connection, either from inetd or a listening TCP socket */
1.64 markus 1787: if (inetd_flag) {
1.345 djm 1788: server_accept_inetd(&sock_in, &sock_out);
1.64 markus 1789: } else {
1.345 djm 1790: server_listen();
1.75 markus 1791:
1.201 markus 1792: if (options.protocol & SSH_PROTO_1)
1793: generate_ephemeral_server_key();
1794:
1795: signal(SIGHUP, sighup_handler);
1.345 djm 1796: signal(SIGCHLD, main_sigchld_handler);
1.201 markus 1797: signal(SIGTERM, sigterm_handler);
1798: signal(SIGQUIT, sigterm_handler);
1799:
1.345 djm 1800: /*
1801: * Write out the pid file after the sigterm handler
1802: * is setup and the listen sockets are bound
1803: */
1804: if (!debug_flag) {
1805: FILE *f = fopen(options.pid_file, "w");
1.201 markus 1806:
1.270 djm 1807: if (f == NULL) {
1808: error("Couldn't create pid file \"%s\": %s",
1809: options.pid_file, strerror(errno));
1810: } else {
1.245 mpech 1811: fprintf(f, "%ld\n", (long) getpid());
1.64 markus 1812: fclose(f);
1813: }
1814: }
1815:
1.345 djm 1816: /* Accept a connection and return in a forked child */
1817: server_accept_loop(&sock_in, &sock_out,
1818: &newsock, config_s);
1.1 deraadt 1819: }
1820:
1.64 markus 1821: /* This is the child processing a new connection. */
1.288 markus 1822: setproctitle("%s", "[accepted]");
1.294 djm 1823:
1.300 markus 1824: /*
1825: * Create a new session and process group since the 4.4BSD
1826: * setlogin() affects the entire process group. We don't
1827: * want the child to be able to affect the parent.
1828: */
1829: if (!debug_flag && !inetd_flag && setsid() < 0)
1830: error("setsid: %.100s", strerror(errno));
1831:
1.294 djm 1832: if (rexec_flag) {
1833: int fd;
1834:
1.296 djm 1835: debug("rexec start in %d out %d newsock %d pipe %d sock %d",
1836: sock_in, sock_out, newsock, startup_pipe, config_s[0]);
1.294 djm 1837: dup2(newsock, STDIN_FILENO);
1838: dup2(STDIN_FILENO, STDOUT_FILENO);
1839: if (startup_pipe == -1)
1.296 djm 1840: close(REEXEC_STARTUP_PIPE_FD);
1.407 djm 1841: else if (startup_pipe != REEXEC_STARTUP_PIPE_FD) {
1.296 djm 1842: dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD);
1.407 djm 1843: close(startup_pipe);
1844: startup_pipe = REEXEC_STARTUP_PIPE_FD;
1845: }
1.294 djm 1846:
1.296 djm 1847: dup2(config_s[1], REEXEC_CONFIG_PASS_FD);
1.294 djm 1848: close(config_s[1]);
1.296 djm 1849:
1.294 djm 1850: execv(rexec_argv[0], rexec_argv);
1851:
1852: /* Reexec has failed, fall back and continue */
1853: error("rexec of %s failed: %s", rexec_argv[0], strerror(errno));
1.296 djm 1854: recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL);
1.294 djm 1855: log_init(__progname, options.log_level,
1856: options.log_facility, log_stderr);
1857:
1858: /* Clean up fds */
1.296 djm 1859: close(REEXEC_CONFIG_PASS_FD);
1860: newsock = sock_out = sock_in = dup(STDIN_FILENO);
1.294 djm 1861: if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1862: dup2(fd, STDIN_FILENO);
1863: dup2(fd, STDOUT_FILENO);
1864: if (fd > STDERR_FILENO)
1865: close(fd);
1866: }
1.296 djm 1867: debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d",
1868: sock_in, sock_out, newsock, startup_pipe, config_s[0]);
1.294 djm 1869: }
1.372 djm 1870:
1871: /* Executed child processes don't need these. */
1872: fcntl(sock_out, F_SETFD, FD_CLOEXEC);
1873: fcntl(sock_in, F_SETFD, FD_CLOEXEC);
1.64 markus 1874:
1.66 markus 1875: /*
1876: * Disable the key regeneration alarm. We will not regenerate the
1877: * key since we are no longer in a position to give it to anyone. We
1878: * will not restart on SIGHUP since it no longer makes sense.
1879: */
1.64 markus 1880: alarm(0);
1881: signal(SIGALRM, SIG_DFL);
1882: signal(SIGHUP, SIG_DFL);
1883: signal(SIGTERM, SIG_DFL);
1884: signal(SIGQUIT, SIG_DFL);
1885: signal(SIGCHLD, SIG_DFL);
1.150 markus 1886:
1.66 markus 1887: /*
1888: * Register our connection. This turns encryption off because we do
1889: * not have a key.
1890: */
1.64 markus 1891: packet_set_connection(sock_in, sock_out);
1.312 markus 1892: packet_set_server();
1.309 djm 1893:
1894: /* Set SO_KEEPALIVE if requested. */
1895: if (options.tcp_keep_alive && packet_connection_is_on_socket() &&
1896: setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0)
1897: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.1 deraadt 1898:
1.310 markus 1899: if ((remote_port = get_remote_port()) < 0) {
1900: debug("get_remote_port failed");
1901: cleanup_exit(255);
1902: }
1.316 dtucker 1903:
1904: /*
1905: * We use get_canonical_hostname with usedns = 0 instead of
1906: * get_remote_ipaddr here so IP options will be checked.
1907: */
1.331 markus 1908: (void) get_canonical_hostname(0);
1909: /*
1910: * The rest of the code depends on the fact that
1911: * get_remote_ipaddr() caches the remote ip, even if
1912: * the socket goes away.
1913: */
1914: remote_ip = get_remote_ipaddr();
1.52 markus 1915:
1.209 markus 1916: #ifdef LIBWRAP
1.64 markus 1917: /* Check whether logins are denied from this host. */
1.295 djm 1918: if (packet_connection_is_on_socket()) {
1.64 markus 1919: struct request_info req;
1.37 dugsong 1920:
1.204 camield 1921: request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
1.64 markus 1922: fromhost(&req);
1.37 dugsong 1923:
1.64 markus 1924: if (!hosts_access(&req)) {
1.209 markus 1925: debug("Connection refused by tcp wrapper");
1.182 markus 1926: refuse(&req);
1.209 markus 1927: /* NOTREACHED */
1928: fatal("libwrap refuse returns");
1.64 markus 1929: }
1930: }
1.75 markus 1931: #endif /* LIBWRAP */
1.209 markus 1932:
1.64 markus 1933: /* Log the connection. */
1.409 djm 1934: verbose("Connection from %s port %d on %s port %d",
1935: remote_ip, remote_port,
1936: get_local_ipaddr(sock_in), get_local_port());
1.1 deraadt 1937:
1.66 markus 1938: /*
1.317 djm 1939: * We don't want to listen forever unless the other side
1.66 markus 1940: * successfully authenticates itself. So we set up an alarm which is
1941: * cleared after successful authentication. A limit of zero
1.317 djm 1942: * indicates no limit. Note that we don't set the alarm in debugging
1.66 markus 1943: * mode; it is just annoying to have the server exit just when you
1944: * are about to discover the bug.
1945: */
1.64 markus 1946: signal(SIGALRM, grace_alarm_handler);
1947: if (!debug_flag)
1948: alarm(options.login_grace_time);
1949:
1.96 markus 1950: sshd_exchange_identification(sock_in, sock_out);
1.353 dtucker 1951:
1952: /* In inetd mode, generate ephemeral key only for proto 1 connections */
1953: if (!compat20 && inetd_flag && sensitive_data.server_key == NULL)
1954: generate_ephemeral_server_key();
1.275 markus 1955:
1.64 markus 1956: packet_set_nonblocking();
1.1 deraadt 1957:
1.278 markus 1958: /* allocate authentication context */
1.329 djm 1959: authctxt = xcalloc(1, sizeof(*authctxt));
1.278 markus 1960:
1961: /* XXX global for cleanup, access from other modules */
1962: the_authctxt = authctxt;
1963:
1.307 otto 1964: /* prepare buffer to collect messages to display to user after login */
1965: buffer_init(&loginmsg);
1.374 dtucker 1966: auth_debug_reset();
1.307 otto 1967:
1.404 markus 1968: if (use_privsep) {
1.278 markus 1969: if (privsep_preauth(authctxt) == 1)
1.237 markus 1970: goto authenticated;
1.404 markus 1971: } else if (compat20 && have_agent)
1972: auth_conn = ssh_get_authentication_connection();
1.231 provos 1973:
1.77 markus 1974: /* perform the key exchange */
1975: /* authenticate user and start session */
1.98 markus 1976: if (compat20) {
1977: do_ssh2_kex();
1.278 markus 1978: do_authentication2(authctxt);
1.98 markus 1979: } else {
1980: do_ssh1_kex();
1.278 markus 1981: do_authentication(authctxt);
1.98 markus 1982: }
1.237 markus 1983: /*
1984: * If we use privilege separation, the unprivileged child transfers
1985: * the current keystate and exits
1986: */
1987: if (use_privsep) {
1.242 mouring 1988: mm_send_keystate(pmonitor);
1.231 provos 1989: exit(0);
1.237 markus 1990: }
1.231 provos 1991:
1992: authenticated:
1.318 djm 1993: /*
1994: * Cancel the alarm we set to limit the time taken for
1995: * authentication.
1996: */
1997: alarm(0);
1998: signal(SIGALRM, SIG_DFL);
1.347 markus 1999: authctxt->authenticated = 1;
1.318 djm 2000: if (startup_pipe != -1) {
2001: close(startup_pipe);
2002: startup_pipe = -1;
2003: }
2004:
1.234 markus 2005: /*
1.231 provos 2006: * In privilege separation, we fork another child and prepare
2007: * file descriptor passing.
2008: */
2009: if (use_privsep) {
1.237 markus 2010: privsep_postauth(authctxt);
2011: /* the monitor process [priv] will not return */
1.231 provos 2012: if (!compat20)
2013: destroy_sensitive_data();
2014: }
1.360 dtucker 2015:
2016: packet_set_timeout(options.client_alive_interval,
2017: options.client_alive_count_max);
1.230 provos 2018:
1.278 markus 2019: /* Start session. */
1.230 provos 2020: do_authenticated(authctxt);
2021:
1.64 markus 2022: /* The connection has been terminated. */
1.364 markus 2023: packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
2024: packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
1.381 djm 2025: verbose("Transferred: sent %llu, received %llu bytes",
2026: (unsigned long long)obytes, (unsigned long long)ibytes);
1.364 markus 2027:
2028: verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
1.64 markus 2029: packet_close();
1.231 provos 2030:
2031: if (use_privsep)
2032: mm_terminate();
2033:
1.64 markus 2034: exit(0);
1.1 deraadt 2035: }
2036:
1.65 deraadt 2037: /*
1.229 markus 2038: * Decrypt session_key_int using our private server key and private host key
2039: * (key with larger modulus first).
2040: */
1.231 provos 2041: int
1.229 markus 2042: ssh1_session_key(BIGNUM *session_key_int)
2043: {
2044: int rsafail = 0;
2045:
1.327 deraadt 2046: if (BN_cmp(sensitive_data.server_key->rsa->n,
2047: sensitive_data.ssh1_host_key->rsa->n) > 0) {
1.229 markus 2048: /* Server key has bigger modulus. */
2049: if (BN_num_bits(sensitive_data.server_key->rsa->n) <
1.327 deraadt 2050: BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
2051: SSH_KEY_BITS_RESERVED) {
2052: fatal("do_connection: %s: "
2053: "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
1.229 markus 2054: get_remote_ipaddr(),
2055: BN_num_bits(sensitive_data.server_key->rsa->n),
2056: BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
2057: SSH_KEY_BITS_RESERVED);
2058: }
2059: if (rsa_private_decrypt(session_key_int, session_key_int,
2060: sensitive_data.server_key->rsa) <= 0)
2061: rsafail++;
2062: if (rsa_private_decrypt(session_key_int, session_key_int,
2063: sensitive_data.ssh1_host_key->rsa) <= 0)
2064: rsafail++;
2065: } else {
2066: /* Host key has bigger modulus (or they are equal). */
2067: if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
1.327 deraadt 2068: BN_num_bits(sensitive_data.server_key->rsa->n) +
2069: SSH_KEY_BITS_RESERVED) {
2070: fatal("do_connection: %s: "
2071: "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
1.229 markus 2072: get_remote_ipaddr(),
2073: BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
2074: BN_num_bits(sensitive_data.server_key->rsa->n),
2075: SSH_KEY_BITS_RESERVED);
2076: }
2077: if (rsa_private_decrypt(session_key_int, session_key_int,
2078: sensitive_data.ssh1_host_key->rsa) < 0)
2079: rsafail++;
2080: if (rsa_private_decrypt(session_key_int, session_key_int,
2081: sensitive_data.server_key->rsa) < 0)
2082: rsafail++;
2083: }
2084: return (rsafail);
2085: }
2086: /*
1.77 markus 2087: * SSH1 key exchange
1.65 deraadt 2088: */
1.200 itojun 2089: static void
1.142 markus 2090: do_ssh1_kex(void)
1.1 deraadt 2091: {
1.64 markus 2092: int i, len;
1.159 markus 2093: int rsafail = 0;
1.64 markus 2094: BIGNUM *session_key_int;
1.140 markus 2095: u_char session_key[SSH_SESSION_KEY_LENGTH];
2096: u_char cookie[8];
2097: u_int cipher_type, auth_mask, protocol_flags;
1.64 markus 2098:
1.66 markus 2099: /*
2100: * Generate check bytes that the client must send back in the user
2101: * packet in order for it to be accepted; this is used to defy ip
2102: * spoofing attacks. Note that this only works against somebody
2103: * doing IP spoofing from a remote machine; any machine on the local
2104: * network can still see outgoing packets and catch the random
2105: * cookie. This only affects rhosts authentication, and this is one
2106: * of the reasons why it is inherently insecure.
2107: */
1.356 djm 2108: arc4random_buf(cookie, sizeof(cookie));
1.64 markus 2109:
1.66 markus 2110: /*
2111: * Send our public key. We include in the packet 64 bits of random
2112: * data that must be matched in the reply in order to prevent IP
2113: * spoofing.
2114: */
1.64 markus 2115: packet_start(SSH_SMSG_PUBLIC_KEY);
2116: for (i = 0; i < 8; i++)
1.77 markus 2117: packet_put_char(cookie[i]);
1.64 markus 2118:
2119: /* Store our public server RSA key. */
1.134 markus 2120: packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
2121: packet_put_bignum(sensitive_data.server_key->rsa->e);
2122: packet_put_bignum(sensitive_data.server_key->rsa->n);
1.64 markus 2123:
2124: /* Store our public host RSA key. */
1.134 markus 2125: packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
2126: packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
2127: packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
1.64 markus 2128:
2129: /* Put protocol flags. */
2130: packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
2131:
2132: /* Declare which ciphers we support. */
1.131 markus 2133: packet_put_int(cipher_mask_ssh1(0));
1.64 markus 2134:
2135: /* Declare supported authentication types. */
2136: auth_mask = 0;
2137: if (options.rhosts_rsa_authentication)
2138: auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
2139: if (options.rsa_authentication)
2140: auth_mask |= 1 << SSH_AUTH_RSA;
1.196 markus 2141: if (options.challenge_response_authentication == 1)
1.64 markus 2142: auth_mask |= 1 << SSH_AUTH_TIS;
2143: if (options.password_authentication)
2144: auth_mask |= 1 << SSH_AUTH_PASSWORD;
2145: packet_put_int(auth_mask);
2146:
2147: /* Send the packet and wait for it to be sent. */
2148: packet_send();
2149: packet_write_wait();
2150:
1.134 markus 2151: debug("Sent %d bit server key and %d bit host key.",
2152: BN_num_bits(sensitive_data.server_key->rsa->n),
2153: BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1.64 markus 2154:
2155: /* Read clients reply (cipher type and session key). */
1.222 markus 2156: packet_read_expect(SSH_CMSG_SESSION_KEY);
1.64 markus 2157:
1.69 markus 2158: /* Get cipher type and check whether we accept this. */
1.64 markus 2159: cipher_type = packet_get_char();
1.69 markus 2160:
1.131 markus 2161: if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
1.69 markus 2162: packet_disconnect("Warning: client selects unsupported cipher.");
1.64 markus 2163:
2164: /* Get check bytes from the packet. These must match those we
2165: sent earlier with the public key packet. */
2166: for (i = 0; i < 8; i++)
1.77 markus 2167: if (cookie[i] != packet_get_char())
1.64 markus 2168: packet_disconnect("IP Spoofing check bytes do not match.");
2169:
2170: debug("Encryption type: %.200s", cipher_name(cipher_type));
2171:
2172: /* Get the encrypted integer. */
1.218 markus 2173: if ((session_key_int = BN_new()) == NULL)
2174: fatal("do_ssh1_kex: BN_new failed");
1.221 markus 2175: packet_get_bignum(session_key_int);
1.64 markus 2176:
2177: protocol_flags = packet_get_int();
2178: packet_set_protocol_flags(protocol_flags);
1.220 markus 2179: packet_check_eom();
1.64 markus 2180:
1.229 markus 2181: /* Decrypt session_key_int using host/server keys */
1.231 provos 2182: rsafail = PRIVSEP(ssh1_session_key(session_key_int));
2183:
1.66 markus 2184: /*
2185: * Extract session key from the decrypted integer. The key is in the
2186: * least significant 256 bits of the integer; the first byte of the
2187: * key is in the highest bits.
2188: */
1.159 markus 2189: if (!rsafail) {
1.348 markus 2190: (void) BN_mask_bits(session_key_int, sizeof(session_key) * 8);
1.159 markus 2191: len = BN_num_bytes(session_key_int);
1.311 djm 2192: if (len < 0 || (u_int)len > sizeof(session_key)) {
1.348 markus 2193: error("do_ssh1_kex: bad session key len from %s: "
1.165 itojun 2194: "session_key_int %d > sizeof(session_key) %lu",
2195: get_remote_ipaddr(), len, (u_long)sizeof(session_key));
1.159 markus 2196: rsafail++;
2197: } else {
2198: memset(session_key, 0, sizeof(session_key));
2199: BN_bn2bin(session_key_int,
2200: session_key + sizeof(session_key) - len);
1.169 markus 2201:
1.291 djm 2202: derive_ssh1_session_id(
1.298 deraadt 2203: sensitive_data.ssh1_host_key->rsa->n,
1.291 djm 2204: sensitive_data.server_key->rsa->n,
2205: cookie, session_id);
1.169 markus 2206: /*
2207: * Xor the first 16 bytes of the session key with the
2208: * session id.
2209: */
2210: for (i = 0; i < 16; i++)
2211: session_key[i] ^= session_id[i];
1.159 markus 2212: }
2213: }
2214: if (rsafail) {
1.169 markus 2215: int bytes = BN_num_bytes(session_key_int);
1.227 stevesk 2216: u_char *buf = xmalloc(bytes);
1.169 markus 2217: MD5_CTX md;
2218:
1.264 itojun 2219: logit("do_connection: generating a fake encryption key");
1.169 markus 2220: BN_bn2bin(session_key_int, buf);
2221: MD5_Init(&md);
2222: MD5_Update(&md, buf, bytes);
2223: MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
2224: MD5_Final(session_key, &md);
2225: MD5_Init(&md);
2226: MD5_Update(&md, session_key, 16);
2227: MD5_Update(&md, buf, bytes);
2228: MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
2229: MD5_Final(session_key + 16, &md);
2230: memset(buf, 0, bytes);
1.402 djm 2231: free(buf);
1.170 markus 2232: for (i = 0; i < 16; i++)
2233: session_id[i] = session_key[i] ^ session_key[i + 16];
1.159 markus 2234: }
1.231 provos 2235: /* Destroy the private and public keys. No longer. */
1.169 markus 2236: destroy_sensitive_data();
2237:
1.231 provos 2238: if (use_privsep)
2239: mm_ssh1_session_id(session_id);
2240:
1.77 markus 2241: /* Destroy the decrypted integer. It is no longer needed. */
2242: BN_clear_free(session_key_int);
1.64 markus 2243:
2244: /* Set the session key. From this on all communications will be encrypted. */
2245: packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
2246:
2247: /* Destroy our copy of the session key. It is no longer needed. */
2248: memset(session_key, 0, sizeof(session_key));
2249:
2250: debug("Received session key; encryption turned on.");
2251:
1.243 deraadt 2252: /* Send an acknowledgment packet. Note that this packet is sent encrypted. */
1.64 markus 2253: packet_start(SSH_SMSG_SUCCESS);
2254: packet_send();
2255: packet_write_wait();
1.98 markus 2256: }
2257:
1.404 markus 2258: void
2259: sshd_hostkey_sign(Key *privkey, Key *pubkey, u_char **signature, u_int *slen,
2260: u_char *data, u_int dlen)
2261: {
2262: if (privkey) {
2263: if (PRIVSEP(key_sign(privkey, signature, slen, data, dlen) < 0))
2264: fatal("%s: key_sign failed", __func__);
2265: } else if (use_privsep) {
2266: if (mm_key_sign(pubkey, signature, slen, data, dlen) < 0)
2267: fatal("%s: pubkey_sign failed", __func__);
2268: } else {
2269: if (ssh_agent_sign(auth_conn, pubkey, signature, slen, data,
2270: dlen))
2271: fatal("%s: ssh_agent_sign failed", __func__);
2272: }
2273: }
2274:
1.98 markus 2275: /*
2276: * SSH2 key exchange: diffie-hellman-group1-sha1
2277: */
1.200 itojun 2278: static void
1.142 markus 2279: do_ssh2_kex(void)
1.98 markus 2280: {
2281: Kex *kex;
1.102 markus 2282:
2283: if (options.ciphers != NULL) {
1.105 markus 2284: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1.102 markus 2285: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
1.166 markus 2286: }
1.184 stevesk 2287: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
2288: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
2289: myproposal[PROPOSAL_ENC_ALGS_STOC] =
2290: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
2291:
1.166 markus 2292: if (options.macs != NULL) {
2293: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
2294: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.246 markus 2295: }
1.312 markus 2296: if (options.compression == COMP_NONE) {
1.246 markus 2297: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
2298: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
1.312 markus 2299: } else if (options.compression == COMP_DELAYED) {
2300: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
2301: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com";
1.102 markus 2302: }
1.380 djm 2303: if (options.kex_algorithms != NULL)
2304: myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
1.400 dtucker 2305:
2306: if (options.rekey_limit || options.rekey_interval)
2307: packet_set_rekey_limits((u_int32_t)options.rekey_limit,
2308: (time_t)options.rekey_interval);
1.327 deraadt 2309:
1.413 djm 2310: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
2311: list_hostkey_types());
1.134 markus 2312:
1.189 markus 2313: /* start key exchange */
1.188 markus 2314: kex = kex_setup(myproposal);
1.263 markus 2315: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1.292 djm 2316: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
1.263 markus 2317: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.324 djm 2318: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1.378 djm 2319: kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
1.410 markus 2320: kex->kex[KEX_C25519_SHA256] = kexc25519_server;
1.186 markus 2321: kex->server = 1;
2322: kex->client_version_string=client_version_string;
2323: kex->server_version_string=server_version_string;
1.373 djm 2324: kex->load_host_public_key=&get_hostkey_public_by_type;
2325: kex->load_host_private_key=&get_hostkey_private_by_type;
1.231 provos 2326: kex->host_key_index=&get_hostkey_index;
1.404 markus 2327: kex->sign = sshd_hostkey_sign;
1.129 provos 2328:
1.189 markus 2329: xxx_kex = kex;
2330:
1.190 markus 2331: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.187 markus 2332:
2333: session_id2 = kex->session_id;
2334: session_id2_len = kex->session_id_len;
1.129 provos 2335:
2336: #ifdef DEBUG_KEXDH
2337: /* send 1st encrypted/maced/compressed message */
2338: packet_start(SSH2_MSG_IGNORE);
2339: packet_put_cstring("markus");
2340: packet_send();
2341: packet_write_wait();
2342: #endif
1.186 markus 2343: debug("KEX done");
1.278 markus 2344: }
2345:
2346: /* server specific fatal cleanup */
2347: void
2348: cleanup_exit(int i)
2349: {
1.386 djm 2350: if (the_authctxt) {
1.278 markus 2351: do_cleanup(the_authctxt);
1.387 dtucker 2352: if (use_privsep && privsep_is_preauth && pmonitor->m_pid > 1) {
1.386 djm 2353: debug("Killing privsep child %d", pmonitor->m_pid);
2354: if (kill(pmonitor->m_pid, SIGKILL) != 0 &&
1.388 djm 2355: errno != ESRCH)
1.386 djm 2356: error("%s: kill(%d): %s", __func__,
2357: pmonitor->m_pid, strerror(errno));
2358: }
2359: }
1.278 markus 2360: _exit(i);
1.1 deraadt 2361: }
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