+/* $OpenBSD: sshd.c,v 1.330 2006/03/25 13:17:02 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.268 2003/06/04 10:23:48 djm Exp $");
+
+#include <sys/types.h>
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif
+#include <sys/ioctl.h>
+#include <sys/wait.h>
+
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <signal.h>
#include <openssl/dh.h>
#include <openssl/bn.h>
#include "rsa.h"
#include "sshpty.h"
#include "packet.h"
-#include "mpaux.h"
#include "log.h"
#include "servconf.h"
#include "uidswap.h"
#include "compat.h"
#include "buffer.h"
+#include "bufaux.h"
#include "cipher.h"
#include "kex.h"
#include "key.h"
#include "canohost.h"
#include "auth.h"
#include "misc.h"
+#include "msg.h"
#include "dispatch.h"
#include "channels.h"
#include "session.h"
#define O_NOCTTY 0
#endif
-#ifdef HAVE___PROGNAME
+/* Re-exec fds */
+#define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
+#define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
+#define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3)
+#define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4)
+
extern char *__progname;
-#else
-char *__progname;
-#endif
/* Server configuration options. */
ServerOptions options;
/* Name of the server configuration file. */
char *config_file_name = _PATH_SERVER_CONFIG_FILE;
-/*
- * Flag indicating whether IPv4 or IPv6. This can be set on the command line.
- * Default value is AF_UNSPEC means both IPv4 and IPv6.
- */
-int IPv4or6 = AF_UNSPEC;
-
/*
* Debug mode flag. This can be set on the command line. If debug
* mode is enabled, extra debugging output will be sent to the system
char **saved_argv;
int saved_argc;
+/* re-exec */
+int rexeced_flag = 0;
+int rexec_flag = 1;
+int rexec_argc = 0;
+char **rexec_argv;
+
/*
* The sockets that the server is listening; this is used in the SIGHUP
* signal handler.
/* same for ssh2 */
u_char *session_id2 = NULL;
-int session_id2_len = 0;
+u_int session_id2_len = 0;
/* record remote hostname or ip */
u_int utmp_len = MAXHOSTNAMELEN;
/* variables used for privilege separation */
int use_privsep;
-struct monitor *pmonitor;
+struct monitor *pmonitor = NULL;
+
+/* global authentication context */
+Authctxt *the_authctxt = NULL;
+
+/* message to be displayed after login */
+Buffer loginmsg;
/* Prototypes for various functions defined later in this file. */
void destroy_sensitive_data(void);
* the effect is to reread the configuration file (and to regenerate
* the server key).
*/
+
+/*ARGSUSED*/
static void
sighup_handler(int sig)
{
/*
* Generic signal handler for terminating signals in the master daemon.
*/
+/*ARGSUSED*/
static void
sigterm_handler(int sig)
{
* SIGCHLD handler. This is called whenever a child dies. This will then
* reap any zombies left by exited children.
*/
+/*ARGSUSED*/
static void
main_sigchld_handler(int sig)
{
/*
* Signal handler for the alarm after the login grace period has expired.
*/
+/*ARGSUSED*/
static void
grace_alarm_handler(int sig)
{
/* XXX no idea how fix this signal handler */
+ if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0)
+ kill(pmonitor->m_pid, SIGALRM);
+
/* Log error and exit. */
fatal("Timeout before authentication for %s", get_remote_ipaddr());
}
arc4random_stir();
}
+/*ARGSUSED*/
static void
key_regeneration_alarm(int sig)
{
static void
sshd_exchange_identification(int sock_in, int sock_out)
{
- int i, mismatch;
+ u_int i;
+ int mismatch;
int remote_major, remote_minor;
int major, minor;
char *s;
snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
server_version_string = xstrdup(buf);
- if (client_version_string == NULL) {
- /* Send our protocol version identification. */
- if (atomicio(write, sock_out, server_version_string,
- strlen(server_version_string))
- != strlen(server_version_string)) {
- logit("Could not write ident string to %s", get_remote_ipaddr());
- fatal_cleanup();
- }
+ /* Send our protocol version identification. */
+ if (atomicio(vwrite, sock_out, server_version_string,
+ strlen(server_version_string))
+ != strlen(server_version_string)) {
+ logit("Could not write ident string to %s", get_remote_ipaddr());
+ cleanup_exit(255);
+ }
- /* Read other sides version identification. */
- memset(buf, 0, sizeof(buf));
- for (i = 0; i < sizeof(buf) - 1; i++) {
- if (atomicio(read, sock_in, &buf[i], 1) != 1) {
- logit("Did not receive identification string from %s",
- get_remote_ipaddr());
- fatal_cleanup();
- }
- if (buf[i] == '\r') {
- buf[i] = 0;
- /* Kludge for F-Secure Macintosh < 1.0.2 */
- if (i == 12 &&
- strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
- break;
- continue;
- }
- if (buf[i] == '\n') {
- buf[i] = 0;
+ /* Read other sides version identification. */
+ memset(buf, 0, sizeof(buf));
+ for (i = 0; i < sizeof(buf) - 1; i++) {
+ if (atomicio(read, sock_in, &buf[i], 1) != 1) {
+ logit("Did not receive identification string from %s",
+ get_remote_ipaddr());
+ cleanup_exit(255);
+ }
+ if (buf[i] == '\r') {
+ buf[i] = 0;
+ /* Kludge for F-Secure Macintosh < 1.0.2 */
+ if (i == 12 &&
+ strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
break;
- }
+ continue;
+ }
+ if (buf[i] == '\n') {
+ buf[i] = 0;
+ break;
}
- buf[sizeof(buf) - 1] = 0;
- client_version_string = xstrdup(buf);
}
+ buf[sizeof(buf) - 1] = 0;
+ client_version_string = xstrdup(buf);
/*
* Check that the versions match. In future this might accept
if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
&remote_major, &remote_minor, remote_version) != 3) {
s = "Protocol mismatch.\n";
- (void) atomicio(write, sock_out, s, strlen(s));
+ (void) atomicio(vwrite, sock_out, s, strlen(s));
close(sock_in);
close(sock_out);
logit("Bad protocol version identification '%.100s' from %s",
client_version_string, get_remote_ipaddr());
- fatal_cleanup();
+ cleanup_exit(255);
}
debug("Client protocol version %d.%d; client software version %.100s",
remote_major, remote_minor, remote_version);
if (datafellows & SSH_BUG_PROBE) {
logit("probed from %s with %s. Don't panic.",
get_remote_ipaddr(), client_version_string);
- fatal_cleanup();
+ cleanup_exit(255);
}
if (datafellows & SSH_BUG_SCANNER) {
logit("scanned from %s with %s. Don't panic.",
get_remote_ipaddr(), client_version_string);
- fatal_cleanup();
+ cleanup_exit(255);
}
mismatch = 0;
if (mismatch) {
s = "Protocol major versions differ.\n";
- (void) atomicio(write, sock_out, s, strlen(s));
+ (void) atomicio(vwrite, sock_out, s, strlen(s));
close(sock_in);
close(sock_out);
logit("Protocol major versions differ for %s: %.200s vs. %.200s",
get_remote_ipaddr(),
server_version_string, client_version_string);
- fatal_cleanup();
+ cleanup_exit(255);
}
}
debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
(u_int)pw->pw_gid);
#if 0
- /* XXX not ready, to heavy after chroot */
+ /* XXX not ready, too heavy after chroot */
do_setusercontext(pw);
#else
gidset[0] = pw->pw_gid;
#endif
}
-static Authctxt *
-privsep_preauth(void)
+static int
+privsep_preauth(Authctxt *authctxt)
{
- Authctxt *authctxt = NULL;
int status;
pid_t pid;
if (pid == -1) {
fatal("fork of unprivileged child failed");
} else if (pid != 0) {
- fatal_remove_cleanup((void (*) (void *)) packet_close, NULL);
-
debug2("Network child is on pid %ld", (long)pid);
close(pmonitor->m_recvfd);
- authctxt = monitor_child_preauth(pmonitor);
+ pmonitor->m_pid = pid;
+ monitor_child_preauth(authctxt, pmonitor);
close(pmonitor->m_sendfd);
/* Sync memory */
while (waitpid(pid, &status, 0) < 0)
if (errno != EINTR)
break;
-
- /* Reinstall, since the child has finished */
- fatal_add_cleanup((void (*) (void *)) packet_close, NULL);
-
- return (authctxt);
+ return (1);
} else {
/* child */
privsep_preauth_child();
setproctitle("%s", "[net]");
}
- return (NULL);
+ return (0);
}
static void
privsep_postauth(Authctxt *authctxt)
{
- extern Authctxt *x_authctxt;
-
- /* XXX - Remote port forwarding */
- x_authctxt = authctxt;
-
#ifdef DISABLE_FD_PASSING
if (1) {
#else
if (authctxt->pw->pw_uid == 0 || options.use_login) {
#endif
/* File descriptor passing is broken or root login */
- monitor_apply_keystate(pmonitor);
use_privsep = 0;
- return;
- }
-
- /* Authentication complete */
- alarm(0);
- if (startup_pipe != -1) {
- close(startup_pipe);
- startup_pipe = -1;
+ goto skip;
}
/* New socket pair */
if (pmonitor->m_pid == -1)
fatal("fork of unprivileged child failed");
else if (pmonitor->m_pid != 0) {
- fatal_remove_cleanup((void (*) (void *)) packet_close, NULL);
-
debug2("User child is on pid %ld", (long)pmonitor->m_pid);
close(pmonitor->m_recvfd);
+ buffer_clear(&loginmsg);
monitor_child_postauth(pmonitor);
/* NEVERREACHED */
/* Drop privileges */
do_setusercontext(authctxt->pw);
+ skip:
/* It is safe now to apply the key state */
monitor_apply_keystate(pmonitor);
+
+ /*
+ * Tell the packet layer that authentication was successful, since
+ * this information is not part of the key state.
+ */
+ packet_set_authenticated();
}
static char *
list_hostkey_types(void)
{
Buffer b;
- char *p;
+ const char *p;
+ char *ret;
int i;
buffer_init(&b);
}
}
buffer_append(&b, "\0", 1);
- p = xstrdup(buffer_ptr(&b));
+ ret = xstrdup(buffer_ptr(&b));
buffer_free(&b);
- debug("list_hostkey_types: %s", p);
- return p;
+ debug("list_hostkey_types: %s", ret);
+ return ret;
}
Key *
static int
drop_connection(int startups)
{
- double p, r;
+ int p, r;
if (startups < options.max_startups_begin)
return 0;
p = 100 - options.max_startups_rate;
p *= startups - options.max_startups_begin;
- p /= (double) (options.max_startups - options.max_startups_begin);
+ p /= options.max_startups - options.max_startups_begin;
p += options.max_startups_rate;
- p /= 100.0;
- r = arc4random() / (double) UINT_MAX;
+ r = arc4random() % 100;
- debug("drop_connection: p %g, r %g", p, r);
+ debug("drop_connection: p %d, r %d", p, r);
return (r < p) ? 1 : 0;
}
static void
usage(void)
{
- fprintf(stderr, "sshd version %s\n", SSH_VERSION);
- fprintf(stderr, "Usage: %s [options]\n", __progname);
- fprintf(stderr, "Options:\n");
- fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE);
- fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n");
- fprintf(stderr, " -i Started from inetd\n");
- fprintf(stderr, " -D Do not fork into daemon mode\n");
- fprintf(stderr, " -t Only test configuration file and keys\n");
- fprintf(stderr, " -q Quiet (no logging)\n");
- fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
- fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
- fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n");
- fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
- fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
- _PATH_HOST_KEY_FILE);
- fprintf(stderr, " -u len Maximum hostname length for utmp recording\n");
- fprintf(stderr, " -4 Use IPv4 only\n");
- fprintf(stderr, " -6 Use IPv6 only\n");
- fprintf(stderr, " -o option Process the option as if it was read from a configuration file.\n");
+ fprintf(stderr, "%s, %s\n",
+ SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
+ fprintf(stderr,
+"usage: sshd [-46Ddeiqt] [-b bits] [-f config_file] [-g login_grace_time]\n"
+" [-h host_key_file] [-k key_gen_time] [-o option] [-p port] [-u len]\n"
+ );
exit(1);
}
+static void
+send_rexec_state(int fd, Buffer *conf)
+{
+ Buffer m;
+
+ debug3("%s: entering fd = %d config len %d", __func__, fd,
+ buffer_len(conf));
+
+ /*
+ * Protocol from reexec master to child:
+ * string configuration
+ * u_int ephemeral_key_follows
+ * bignum e (only if ephemeral_key_follows == 1)
+ * bignum n "
+ * bignum d "
+ * bignum iqmp "
+ * bignum p "
+ * bignum q "
+ * string rngseed (only if OpenSSL is not self-seeded)
+ */
+ buffer_init(&m);
+ buffer_put_cstring(&m, buffer_ptr(conf));
+
+ if (sensitive_data.server_key != NULL &&
+ sensitive_data.server_key->type == KEY_RSA1) {
+ buffer_put_int(&m, 1);
+ buffer_put_bignum(&m, sensitive_data.server_key->rsa->e);
+ buffer_put_bignum(&m, sensitive_data.server_key->rsa->n);
+ buffer_put_bignum(&m, sensitive_data.server_key->rsa->d);
+ buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp);
+ buffer_put_bignum(&m, sensitive_data.server_key->rsa->p);
+ buffer_put_bignum(&m, sensitive_data.server_key->rsa->q);
+ } else
+ buffer_put_int(&m, 0);
+
+#ifndef OPENSSL_PRNG_ONLY
+ rexec_send_rng_seed(&m);
+#endif
+
+ if (ssh_msg_send(fd, 0, &m) == -1)
+ fatal("%s: ssh_msg_send failed", __func__);
+
+ buffer_free(&m);
+
+ debug3("%s: done", __func__);
+}
+
+static void
+recv_rexec_state(int fd, Buffer *conf)
+{
+ Buffer m;
+ char *cp;
+ u_int len;
+
+ debug3("%s: entering fd = %d", __func__, fd);
+
+ buffer_init(&m);
+
+ if (ssh_msg_recv(fd, &m) == -1)
+ fatal("%s: ssh_msg_recv failed", __func__);
+ if (buffer_get_char(&m) != 0)
+ fatal("%s: rexec version mismatch", __func__);
+
+ cp = buffer_get_string(&m, &len);
+ if (conf != NULL)
+ buffer_append(conf, cp, len + 1);
+ xfree(cp);
+
+ if (buffer_get_int(&m)) {
+ if (sensitive_data.server_key != NULL)
+ key_free(sensitive_data.server_key);
+ sensitive_data.server_key = key_new_private(KEY_RSA1);
+ buffer_get_bignum(&m, sensitive_data.server_key->rsa->e);
+ buffer_get_bignum(&m, sensitive_data.server_key->rsa->n);
+ buffer_get_bignum(&m, sensitive_data.server_key->rsa->d);
+ buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp);
+ buffer_get_bignum(&m, sensitive_data.server_key->rsa->p);
+ buffer_get_bignum(&m, sensitive_data.server_key->rsa->q);
+ rsa_generate_additional_parameters(
+ sensitive_data.server_key->rsa);
+ }
+
+#ifndef OPENSSL_PRNG_ONLY
+ rexec_recv_rng_seed(&m);
+#endif
+
+ buffer_free(&m);
+
+ debug3("%s: done", __func__);
+}
+
/*
* Main program for the daemon.
*/
{
extern char *optarg;
extern int optind;
- int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
+ int opt, j, i, on = 1;
+ int sock_in = -1, sock_out = -1, newsock = -1;
pid_t pid;
socklen_t fromlen;
fd_set *fdset;
FILE *f;
struct addrinfo *ai;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+ char *line;
int listen_sock, maxfd;
- int startup_p[2];
+ int startup_p[2] = { -1 , -1 }, config_s[2] = { -1 , -1 };
int startups = 0;
- Authctxt *authctxt;
Key *key;
+ Authctxt *authctxt;
int ret, key_used = 0;
+ Buffer cfg;
#ifdef HAVE_SECUREWARE
(void)set_auth_parameters(ac, av);
#endif
- __progname = get_progname(av[0]);
+ __progname = ssh_get_progname(av[0]);
init_rng();
/* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
saved_argc = ac;
+ rexec_argc = ac;
saved_argv = xmalloc(sizeof(*saved_argv) * (ac + 1));
for (i = 0; i < ac; i++)
saved_argv[i] = xstrdup(av[i]);
av = saved_argv;
#endif
+ if (geteuid() == 0 && setgroups(0, NULL) == -1)
+ debug("setgroups(): %.200s", strerror(errno));
+
+ /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
+ sanitise_stdfd();
+
/* Initialize configuration options to their default values. */
initialize_server_options(&options);
/* Parse command-line arguments. */
- while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:o:dDeiqtQ46")) != -1) {
+ while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqrtQR46")) != -1) {
switch (opt) {
case '4':
- IPv4or6 = AF_INET;
+ options.address_family = AF_INET;
break;
case '6':
- IPv4or6 = AF_INET6;
+ options.address_family = AF_INET6;
break;
case 'f':
config_file_name = optarg;
break;
case 'd':
- if (0 == debug_flag) {
+ if (debug_flag == 0) {
debug_flag = 1;
options.log_level = SYSLOG_LEVEL_DEBUG1;
- } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
+ } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
options.log_level++;
- } else {
- fprintf(stderr, "Too high debugging level.\n");
- exit(1);
- }
break;
case 'D':
no_daemon_flag = 1;
case 'i':
inetd_flag = 1;
break;
+ case 'r':
+ rexec_flag = 0;
+ break;
+ case 'R':
+ rexeced_flag = 1;
+ inetd_flag = 1;
+ break;
case 'Q':
/* ignored */
break;
options.log_level = SYSLOG_LEVEL_QUIET;
break;
case 'b':
- options.server_key_bits = atoi(optarg);
+ options.server_key_bits = (int)strtonum(optarg, 256,
+ 32768, NULL);
break;
case 'p':
options.ports_from_cmdline = 1;
}
options.host_key_files[options.num_host_key_files++] = optarg;
break;
- case 'V':
- client_version_string = optarg;
- /* only makes sense with inetd_flag, i.e. no listen() */
- inetd_flag = 1;
- break;
case 't':
test_flag = 1;
break;
case 'u':
- utmp_len = atoi(optarg);
+ utmp_len = (u_int)strtonum(optarg, 0, MAXHOSTNAMELEN+1, NULL);
if (utmp_len > MAXHOSTNAMELEN) {
fprintf(stderr, "Invalid utmp length.\n");
exit(1);
}
break;
case 'o':
- if (process_server_config_line(&options, optarg,
+ line = xstrdup(optarg);
+ if (process_server_config_line(&options, line,
"command-line", 0) != 0)
exit(1);
+ xfree(line);
break;
case '?':
default:
break;
}
}
+ if (rexeced_flag || inetd_flag)
+ rexec_flag = 0;
+ if (rexec_flag && (av[0] == NULL || *av[0] != '/'))
+ fatal("sshd re-exec requires execution with an absolute path");
+ if (rexeced_flag)
+ closefrom(REEXEC_MIN_FREE_FD);
+ else
+ closefrom(REEXEC_DEVCRYPTO_RESERVED_FD);
+
SSLeay_add_all_algorithms();
- channel_set_af(IPv4or6);
/*
* Force logging to stderr until we have loaded the private host
SYSLOG_FACILITY_AUTH : options.log_facility,
log_stderr || !inetd_flag);
+ /*
+ * Unset KRB5CCNAME, otherwise the user's session may inherit it from
+ * root's environment
+ */
+ if (getenv("KRB5CCNAME") != NULL)
+ unsetenv("KRB5CCNAME");
+
#ifdef _UNICOS
- /* Cray can define user privs drop all prives now!
+ /* Cray can define user privs drop all privs now!
* Not needed on PRIV_SU systems!
*/
drop_cray_privs();
#endif
- seed_rng();
+ sensitive_data.server_key = NULL;
+ sensitive_data.ssh1_host_key = NULL;
+ sensitive_data.have_ssh1_key = 0;
+ sensitive_data.have_ssh2_key = 0;
+
+ /* Fetch our configuration */
+ buffer_init(&cfg);
+ if (rexeced_flag)
+ recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg);
+ else
+ load_server_config(config_file_name, &cfg);
- /* Read server configuration options from the configuration file. */
- read_server_config(&options, config_file_name);
+ parse_server_config(&options,
+ rexeced_flag ? "rexec" : config_file_name, &cfg);
+
+ if (!rexec_flag)
+ buffer_free(&cfg);
+
+ seed_rng();
/* Fill in default values for those options not explicitly set. */
fill_default_server_options(&options);
+ /* set default channel AF */
+ channel_set_af(options.address_family);
+
/* Check that there are no remaining arguments. */
if (optind < ac) {
fprintf(stderr, "Extra argument %s.\n", av[optind]);
exit(1);
}
- debug("sshd version %.100s", SSH_VERSION);
+ debug("sshd version %.100s", SSH_RELEASE);
/* load private host keys */
- sensitive_data.host_keys = xmalloc(options.num_host_key_files *
+ sensitive_data.host_keys = xcalloc(options.num_host_key_files,
sizeof(Key *));
for (i = 0; i < options.num_host_key_files; i++)
sensitive_data.host_keys[i] = NULL;
- sensitive_data.server_key = NULL;
- sensitive_data.ssh1_host_key = NULL;
- sensitive_data.have_ssh1_key = 0;
- sensitive_data.have_ssh2_key = 0;
for (i = 0; i < options.num_host_key_files; i++) {
key = key_load_private(options.host_key_files[i], "", NULL);
}
if (use_privsep) {
- struct passwd *pw;
struct stat st;
- if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
+ if (getpwnam(SSH_PRIVSEP_USER) == NULL)
fatal("Privilege separation user %s does not exist",
SSH_PRIVSEP_USER);
if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
/*
* Clear out any supplemental groups we may have inherited. This
* prevents inadvertent creation of files with bad modes (in the
- * portable version at least, it's certainly possible for PAM
- * to create a file, and we can't control the code in every
+ * portable version at least, it's certainly possible for PAM
+ * to create a file, and we can't control the code in every
* module which might be used).
*/
if (setgroups(0, NULL) < 0)
debug("setgroups() failed: %.200s", strerror(errno));
+ if (rexec_flag) {
+ rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *));
+ for (i = 0; i < rexec_argc; i++) {
+ debug("rexec_argv[%d]='%s'", i, saved_argv[i]);
+ rexec_argv[i] = saved_argv[i];
+ }
+ rexec_argv[rexec_argc] = "-R";
+ rexec_argv[rexec_argc + 1] = NULL;
+ }
+
/* Initialize the log (it is reinitialized below in case we forked). */
- if (debug_flag && !inetd_flag)
+ if (debug_flag && (!inetd_flag || rexeced_flag))
log_stderr = 1;
log_init(__progname, options.log_level, options.log_facility, log_stderr);
/* Start listening for a socket, unless started from inetd. */
if (inetd_flag) {
- int s1;
- s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */
- dup(s1);
- sock_in = dup(0);
- sock_out = dup(1);
+ int fd;
+
startup_pipe = -1;
+ if (rexeced_flag) {
+ close(REEXEC_CONFIG_PASS_FD);
+ sock_in = sock_out = dup(STDIN_FILENO);
+ if (!debug_flag) {
+ startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
+ close(REEXEC_STARTUP_PIPE_FD);
+ }
+ } else {
+ sock_in = dup(STDIN_FILENO);
+ sock_out = dup(STDOUT_FILENO);
+ }
/*
* We intentionally do not close the descriptors 0, 1, and 2
- * as our code for setting the descriptors won\'t work if
+ * as our code for setting the descriptors won't work if
* ttyfd happens to be one of those.
*/
+ if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
+ dup2(fd, STDIN_FILENO);
+ dup2(fd, STDOUT_FILENO);
+ if (fd > STDOUT_FILENO)
+ close(fd);
+ }
debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
- if (options.protocol & SSH_PROTO_1)
+ if ((options.protocol & SSH_PROTO_1) &&
+ sensitive_data.server_key == NULL)
generate_ephemeral_server_key();
} else {
for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
if (num_listen_socks >= MAX_LISTEN_SOCKS)
fatal("Too many listen sockets. "
"Enlarge MAX_LISTEN_SOCKS");
- if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
+ if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
ntop, sizeof(ntop), strport, sizeof(strport),
- NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
- error("getnameinfo failed");
+ NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
+ error("getnameinfo failed: %.100s",
+ (ret != EAI_SYSTEM) ? gai_strerror(ret) :
+ strerror(errno));
continue;
}
/* Create socket for listening. */
verbose("socket: %.100s", strerror(errno));
continue;
}
- if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) {
- error("listen_sock O_NONBLOCK: %s", strerror(errno));
+ if (set_nonblock(listen_sock) == -1) {
close(listen_sock);
continue;
}
num_listen_socks++;
/* Start listening on the port. */
+ if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
+ fatal("listen on [%s]:%s: %.100s",
+ ntop, strport, strerror(errno));
logit("Server listening on %s port %s.", ntop, strport);
- if (listen(listen_sock, 5) < 0)
- fatal("listen: %.100s", strerror(errno));
-
}
freeaddrinfo(options.listen_addrs);
* overwrite any old pid in the file.
*/
f = fopen(options.pid_file, "wb");
- if (f) {
+ if (f == NULL) {
+ error("Couldn't create pid file \"%s\": %s",
+ options.pid_file, strerror(errno));
+ } else {
fprintf(f, "%ld\n", (long) getpid());
fclose(f);
}
if (listen_socks[i] > maxfd)
maxfd = listen_socks[i];
/* pipes connected to unauthenticated childs */
- startup_pipes = xmalloc(options.max_startups * sizeof(int));
+ startup_pipes = xcalloc(options.max_startups, sizeof(int));
for (i = 0; i < options.max_startups; i++)
startup_pipes[i] = -1;
sighup_restart();
if (fdset != NULL)
xfree(fdset);
- fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
- fdset = (fd_set *)xmalloc(fdsetsz);
- memset(fdset, 0, fdsetsz);
+ fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS),
+ sizeof(fd_mask));
for (i = 0; i < num_listen_socks; i++)
FD_SET(listen_socks[i], fdset);
if (!FD_ISSET(listen_socks[i], fdset))
continue;
fromlen = sizeof(from);
- newsock = accept(listen_socks[i], (struct sockaddr *)&from,
- &fromlen);
+ newsock = accept(listen_socks[i],
+ (struct sockaddr *)&from, &fromlen);
if (newsock < 0) {
if (errno != EINTR && errno != EWOULDBLOCK)
error("accept: %.100s", strerror(errno));
continue;
}
- if (fcntl(newsock, F_SETFL, 0) < 0) {
- error("newsock del O_NONBLOCK: %s", strerror(errno));
+ if (unset_nonblock(newsock) == -1) {
close(newsock);
continue;
}
continue;
}
+ if (rexec_flag && socketpair(AF_UNIX,
+ SOCK_STREAM, 0, config_s) == -1) {
+ error("reexec socketpair: %s",
+ strerror(errno));
+ close(newsock);
+ close(startup_p[0]);
+ close(startup_p[1]);
+ continue;
+ }
+
for (j = 0; j < options.max_startups; j++)
if (startup_pipes[j] == -1) {
startup_pipes[j] = startup_p[0];
close_listen_socks();
sock_in = newsock;
sock_out = newsock;
+ close(startup_p[0]);
+ close(startup_p[1]);
startup_pipe = -1;
pid = getpid();
+ if (rexec_flag) {
+ send_rexec_state(config_s[0],
+ &cfg);
+ close(config_s[0]);
+ }
break;
} else {
/*
*/
if ((pid = fork()) == 0) {
/*
- * Child. Close the listening and max_startup
- * sockets. Start using the accepted socket.
- * Reinitialize logging (since our pid has
- * changed). We break out of the loop to handle
+ * Child. Close the listening and
+ * max_startup sockets. Start using
+ * the accepted socket. Reinitialize
+ * logging (since our pid has changed).
+ * We break out of the loop to handle
* the connection.
*/
startup_pipe = startup_p[1];
close_listen_socks();
sock_in = newsock;
sock_out = newsock;
- log_init(__progname, options.log_level, options.log_facility, log_stderr);
+ log_init(__progname,
+ options.log_level,
+ options.log_facility,
+ log_stderr);
+ if (rexec_flag)
+ close(config_s[0]);
break;
}
}
close(startup_p[1]);
- /* Mark that the key has been used (it was "given" to the child). */
+ if (rexec_flag) {
+ send_rexec_state(config_s[0], &cfg);
+ close(config_s[0]);
+ close(config_s[1]);
+ }
+
+ /*
+ * Mark that the key has been used (it
+ * was "given" to the child).
+ */
if ((options.protocol & SSH_PROTO_1) &&
key_used == 0) {
/* Schedule server key regeneration alarm. */
- mysignal(SIGALRM, key_regeneration_alarm);
+ signal(SIGALRM, key_regeneration_alarm);
alarm(options.key_regeneration_time);
key_used = 1;
}
arc4random_stir();
-
- /* Close the new socket (the child is now taking care of it). */
close(newsock);
}
/* child process check (or debug mode) */
}
/* This is the child processing a new connection. */
+ setproctitle("%s", "[accepted]");
/*
* Create a new session and process group since the 4.4BSD
error("setsid: %.100s", strerror(errno));
#endif
+ if (rexec_flag) {
+ int fd;
+
+ debug("rexec start in %d out %d newsock %d pipe %d sock %d",
+ sock_in, sock_out, newsock, startup_pipe, config_s[0]);
+ dup2(newsock, STDIN_FILENO);
+ dup2(STDIN_FILENO, STDOUT_FILENO);
+ if (startup_pipe == -1)
+ close(REEXEC_STARTUP_PIPE_FD);
+ else
+ dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD);
+
+ dup2(config_s[1], REEXEC_CONFIG_PASS_FD);
+ close(config_s[1]);
+ if (startup_pipe != -1)
+ close(startup_pipe);
+
+ execv(rexec_argv[0], rexec_argv);
+
+ /* Reexec has failed, fall back and continue */
+ error("rexec of %s failed: %s", rexec_argv[0], strerror(errno));
+ recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL);
+ log_init(__progname, options.log_level,
+ options.log_facility, log_stderr);
+
+ /* Clean up fds */
+ startup_pipe = REEXEC_STARTUP_PIPE_FD;
+ close(config_s[1]);
+ close(REEXEC_CONFIG_PASS_FD);
+ newsock = sock_out = sock_in = dup(STDIN_FILENO);
+ if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
+ dup2(fd, STDIN_FILENO);
+ dup2(fd, STDOUT_FILENO);
+ if (fd > STDERR_FILENO)
+ close(fd);
+ }
+ debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d",
+ sock_in, sock_out, newsock, startup_pipe, config_s[0]);
+ }
+
/*
* Disable the key regeneration alarm. We will not regenerate the
* key since we are no longer in a position to give it to anyone. We
signal(SIGCHLD, SIG_DFL);
signal(SIGINT, SIG_DFL);
- /* Set keepalives if requested. */
- if (options.keepalives &&
- setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on,
- sizeof(on)) < 0)
- error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
-
/*
* Register our connection. This turns encryption off because we do
* not have a key.
*/
packet_set_connection(sock_in, sock_out);
+ packet_set_server();
+
+ /* Set SO_KEEPALIVE if requested. */
+ if (options.tcp_keep_alive && packet_connection_is_on_socket() &&
+ setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0)
+ error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
+
+ if ((remote_port = get_remote_port()) < 0) {
+ debug("get_remote_port failed");
+ cleanup_exit(255);
+ }
- remote_port = get_remote_port();
- remote_ip = get_remote_ipaddr();
+ /*
+ * We use get_canonical_hostname with usedns = 0 instead of
+ * get_remote_ipaddr here so IP options will be checked.
+ */
+ remote_ip = get_canonical_hostname(0);
+#ifdef SSH_AUDIT_EVENTS
+ audit_connection_from(remote_ip, remote_port);
+#endif
#ifdef LIBWRAP
/* Check whether logins are denied from this host. */
- {
+ if (packet_connection_is_on_socket()) {
struct request_info req;
request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
verbose("Connection from %.500s port %d", remote_ip, remote_port);
/*
- * We don\'t want to listen forever unless the other side
+ * We don't want to listen forever unless the other side
* successfully authenticates itself. So we set up an alarm which is
* cleared after successful authentication. A limit of zero
- * indicates no limit. Note that we don\'t set the alarm in debugging
+ * indicates no limit. Note that we don't set the alarm in debugging
* mode; it is just annoying to have the server exit just when you
* are about to discover the bug.
*/
- mysignal(SIGALRM, grace_alarm_handler);
+ signal(SIGALRM, grace_alarm_handler);
if (!debug_flag)
alarm(options.login_grace_time);
sshd_exchange_identification(sock_in, sock_out);
- /*
- * Check that the connection comes from a privileged port.
- * Rhosts-Authentication only makes sense from privileged
- * programs. Of course, if the intruder has root access on his local
- * machine, he can connect from any port. So do not use these
- * authentication methods from machines that you do not trust.
- */
- if (options.rhosts_authentication &&
- (remote_port >= IPPORT_RESERVED ||
- remote_port < IPPORT_RESERVED / 2)) {
- debug("Rhosts Authentication disabled, "
- "originating port %d not trusted.", remote_port);
- options.rhosts_authentication = 0;
- }
-#if defined(KRB4) && !defined(KRB5)
- if (!packet_connection_is_ipv4() &&
- options.kerberos_authentication) {
- debug("Kerberos Authentication disabled, only available for IPv4.");
- options.kerberos_authentication = 0;
- }
-#endif /* KRB4 && !KRB5 */
-#ifdef AFS
- /* If machine has AFS, set process authentication group. */
- if (k_hasafs()) {
- k_setpag();
- k_unlog();
- }
-#endif /* AFS */
packet_set_nonblocking();
+ /* allocate authentication context */
+ authctxt = xcalloc(1, sizeof(*authctxt));
+
+ authctxt->loginmsg = &loginmsg;
+
+ /* XXX global for cleanup, access from other modules */
+ the_authctxt = authctxt;
+
+ /* prepare buffer to collect messages to display to user after login */
+ buffer_init(&loginmsg);
+
if (use_privsep)
- if ((authctxt = privsep_preauth()) != NULL)
+ if (privsep_preauth(authctxt) == 1)
goto authenticated;
/* perform the key exchange */
/* authenticate user and start session */
if (compat20) {
do_ssh2_kex();
- authctxt = do_authentication2();
+ do_authentication2(authctxt);
} else {
do_ssh1_kex();
- authctxt = do_authentication();
+ do_authentication(authctxt);
}
/*
* If we use privilege separation, the unprivileged child transfers
}
authenticated:
+ /*
+ * Cancel the alarm we set to limit the time taken for
+ * authentication.
+ */
+ alarm(0);
+ signal(SIGALRM, SIG_DFL);
+ if (startup_pipe != -1) {
+ close(startup_pipe);
+ startup_pipe = -1;
+ }
+
+#ifdef SSH_AUDIT_EVENTS
+ audit_event(SSH_AUTH_SUCCESS);
+#endif
+
/*
* In privilege separation, we fork another child and prepare
* file descriptor passing.
destroy_sensitive_data();
}
- /* Perform session preparation. */
+ /* Start session. */
do_authenticated(authctxt);
/* The connection has been terminated. */
finish_pam();
#endif /* USE_PAM */
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(SSH_CONNECTION_CLOSE));
+#endif
+
packet_close();
if (use_privsep)
{
int rsafail = 0;
- if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) {
+ if (BN_cmp(sensitive_data.server_key->rsa->n,
+ sensitive_data.ssh1_host_key->rsa->n) > 0) {
/* Server key has bigger modulus. */
if (BN_num_bits(sensitive_data.server_key->rsa->n) <
- BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
- fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
+ BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
+ SSH_KEY_BITS_RESERVED) {
+ fatal("do_connection: %s: "
+ "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
get_remote_ipaddr(),
BN_num_bits(sensitive_data.server_key->rsa->n),
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
} else {
/* Host key has bigger modulus (or they are equal). */
if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
- BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
- fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
+ BN_num_bits(sensitive_data.server_key->rsa->n) +
+ SSH_KEY_BITS_RESERVED) {
+ fatal("do_connection: %s: "
+ "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
get_remote_ipaddr(),
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
BN_num_bits(sensitive_data.server_key->rsa->n),
/* Declare supported authentication types. */
auth_mask = 0;
- if (options.rhosts_authentication)
- auth_mask |= 1 << SSH_AUTH_RHOSTS;
if (options.rhosts_rsa_authentication)
auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
if (options.rsa_authentication)
auth_mask |= 1 << SSH_AUTH_RSA;
-#if defined(KRB4) || defined(KRB5)
- if (options.kerberos_authentication)
- auth_mask |= 1 << SSH_AUTH_KERBEROS;
-#endif
-#if defined(AFS) || defined(KRB5)
- if (options.kerberos_tgt_passing)
- auth_mask |= 1 << SSH_PASS_KERBEROS_TGT;
-#endif
-#ifdef AFS
- if (options.afs_token_passing)
- auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
-#endif
if (options.challenge_response_authentication == 1)
auth_mask |= 1 << SSH_AUTH_TIS;
if (options.password_authentication)
if (!rsafail) {
BN_mask_bits(session_key_int, sizeof(session_key) * 8);
len = BN_num_bytes(session_key_int);
- if (len < 0 || len > sizeof(session_key)) {
+ if (len < 0 || (u_int)len > sizeof(session_key)) {
error("do_connection: bad session key len from %s: "
"session_key_int %d > sizeof(session_key) %lu",
get_remote_ipaddr(), len, (u_long)sizeof(session_key));
BN_bn2bin(session_key_int,
session_key + sizeof(session_key) - len);
- compute_session_id(session_id, cookie,
+ derive_ssh1_session_id(
sensitive_data.ssh1_host_key->rsa->n,
- sensitive_data.server_key->rsa->n);
+ sensitive_data.server_key->rsa->n,
+ cookie, session_id);
/*
* Xor the first 16 bytes of the session key with the
* session id.
myproposal[PROPOSAL_MAC_ALGS_CTOS] =
myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
}
- if (!options.compression) {
+ if (options.compression == COMP_NONE) {
myproposal[PROPOSAL_COMP_ALGS_CTOS] =
myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
+ } else if (options.compression == COMP_DELAYED) {
+ myproposal[PROPOSAL_COMP_ALGS_CTOS] =
+ myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com";
}
+
myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
/* start key exchange */
kex = kex_setup(myproposal);
kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
+ kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
+ kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
kex->server = 1;
kex->client_version_string=client_version_string;
kex->server_version_string=server_version_string;
#endif
debug("KEX done");
}
+
+/* server specific fatal cleanup */
+void
+cleanup_exit(int i)
+{
+ if (the_authctxt)
+ do_cleanup(the_authctxt);
+#ifdef SSH_AUDIT_EVENTS
+ /* done after do_cleanup so it can cancel the PAM auth 'thread' */
+ if (!use_privsep || mm_is_monitor())
+ audit_event(SSH_CONNECTION_ABANDON);
+#endif
+ _exit(i);
+}
andersk / openssh.git / blobdiff