+/* $OpenBSD: sshd.c,v 1.372 2010/01/29 00:20:41 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 1.325 2006/03/13 08:16:00 djm Exp $");
#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
-#include <sys/ioctl.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include "openbsd-compat/sys-tree.h"
+#include "openbsd-compat/sys-queue.h"
#include <sys/wait.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#ifdef HAVE_PATHS_H
#include <paths.h>
+#endif
+#include <grp.h>
+#include <pwd.h>
#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
#include <openssl/dh.h>
#include <openssl/bn.h>
#include <openssl/md5.h>
#include <openssl/rand.h>
+#include "openbsd-compat/openssl-compat.h"
+
#ifdef HAVE_SECUREWARE
#include <sys/security.h>
#include <prot.h>
#endif
+#include "xmalloc.h"
#include "ssh.h"
#include "ssh1.h"
#include "ssh2.h"
-#include "xmalloc.h"
#include "rsa.h"
#include "sshpty.h"
#include "packet.h"
#include "log.h"
+#include "buffer.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 "kex.h"
#include "dh.h"
#include "myproposal.h"
#include "authfile.h"
#include "pathnames.h"
#include "atomicio.h"
#include "canohost.h"
+#include "hostfile.h"
#include "auth.h"
#include "misc.h"
#include "msg.h"
#include "session.h"
#include "monitor_mm.h"
#include "monitor.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
#include "monitor_wrap.h"
-#include "monitor_fdpass.h"
+#include "roaming.h"
+#include "version.h"
#ifdef LIBWRAP
#include <tcpd.h>
#include <syslog.h>
-int allow_severity = LOG_INFO;
-int deny_severity = LOG_WARNING;
+int allow_severity;
+int deny_severity;
#endif /* LIBWRAP */
#ifndef O_NOCTTY
int startup_pipe; /* in child */
/* variables used for privilege separation */
-int use_privsep;
+int use_privsep = -1;
struct monitor *pmonitor = NULL;
/* global authentication context */
Authctxt *the_authctxt = NULL;
+/* sshd_config buffer */
+Buffer cfg;
+
/* message to be displayed after login */
Buffer loginmsg;
+/* Unprivileged user */
+struct passwd *privsep_pw = NULL;
+
/* Prototypes for various functions defined later in this file. */
void destroy_sensitive_data(void);
void demote_sensitive_data(void);
* the effect is to reread the configuration file (and to regenerate
* the server key).
*/
+
+/*ARGSUSED*/
static void
sighup_handler(int sig)
{
logit("Received SIGHUP; restarting.");
close_listen_socks();
close_startup_pipes();
+ alarm(0); /* alarm timer persists across exec */
+ signal(SIGHUP, SIG_IGN); /* will be restored after exec */
execv(saved_argv[0], saved_argv);
logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
strerror(errno));
/*
* 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());
+ sigdie("Timeout before authentication for %s", get_remote_ipaddr());
}
/*
static void
generate_ephemeral_server_key(void)
{
- u_int32_t rnd = 0;
- int i;
-
verbose("Generating %s%d bit RSA key.",
sensitive_data.server_key ? "new " : "", options.server_key_bits);
if (sensitive_data.server_key != NULL)
options.server_key_bits);
verbose("RSA key generation complete.");
- for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
- if (i % 4 == 0)
- rnd = arc4random();
- sensitive_data.ssh1_cookie[i] = rnd & 0xff;
- rnd >>= 8;
- }
+ arc4random_buf(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
arc4random_stir();
}
+/*ARGSUSED*/
static void
key_regeneration_alarm(int sig)
{
int mismatch;
int remote_major, remote_minor;
int major, minor;
- char *s;
+ char *s, *newline = "\n";
char buf[256]; /* Must not be larger than remote_version. */
char remote_version[256]; /* Must be at least as big as buf. */
} else if (options.protocol & SSH_PROTO_2) {
major = PROTOCOL_MAJOR_2;
minor = PROTOCOL_MINOR_2;
+ newline = "\r\n";
} else {
major = PROTOCOL_MAJOR_1;
minor = PROTOCOL_MINOR_1;
}
- snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
+ snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s%s", major, minor,
+ SSH_VERSION, newline);
server_version_string = xstrdup(buf);
/* Send our protocol version identification. */
- if (atomicio(vwrite, sock_out, server_version_string,
+ if (roaming_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());
/* 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) {
+ if (roaming_atomicio(read, sock_in, &buf[i], 1) != 1) {
logit("Did not receive identification string from %s",
get_remote_ipaddr());
cleanup_exit(255);
{
u_int32_t rnd[256];
gid_t gidset[1];
- struct passwd *pw;
- int i;
/* Enable challenge-response authentication for privilege separation */
privsep_challenge_enable();
- for (i = 0; i < 256; i++)
- rnd[i] = arc4random();
+ arc4random_stir();
+ arc4random_buf(rnd, sizeof(rnd));
RAND_seed(rnd, sizeof(rnd));
/* Demote the private keys to public keys. */
demote_sensitive_data();
- if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
- fatal("Privilege separation user %s does not exist",
- SSH_PRIVSEP_USER);
- memset(pw->pw_passwd, 0, strlen(pw->pw_passwd));
- endpwent();
-
/* Change our root directory */
if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
fatal("chdir(\"/\"): %s", strerror(errno));
/* Drop our privileges */
- debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
- (u_int)pw->pw_gid);
+ debug3("privsep user:group %u:%u", (u_int)privsep_pw->pw_uid,
+ (u_int)privsep_pw->pw_gid);
#if 0
/* XXX not ready, too heavy after chroot */
- do_setusercontext(pw);
+ do_setusercontext(privsep_pw);
#else
- gidset[0] = pw->pw_gid;
+ gidset[0] = privsep_pw->pw_gid;
if (setgroups(1, gidset) < 0)
fatal("setgroups: %.100s", strerror(errno));
- permanently_set_uid(pw);
+ permanently_set_uid(privsep_pw);
#endif
}
static void
privsep_postauth(Authctxt *authctxt)
{
+ u_int32_t rnd[256];
+
#ifdef DISABLE_FD_PASSING
if (1) {
#else
if (pmonitor->m_pid == -1)
fatal("fork of unprivileged child failed");
else if (pmonitor->m_pid != 0) {
- debug2("User child is on pid %ld", (long)pmonitor->m_pid);
+ verbose("User child is on pid %ld", (long)pmonitor->m_pid);
close(pmonitor->m_recvfd);
buffer_clear(&loginmsg);
monitor_child_postauth(pmonitor);
/* Demote the private keys to public keys. */
demote_sensitive_data();
+ arc4random_stir();
+ arc4random_buf(rnd, sizeof(rnd));
+ RAND_seed(rnd, sizeof(rnd));
+
/* Drop privileges */
do_setusercontext(authctxt->pw);
p *= startups - options.max_startups_begin;
p /= options.max_startups - options.max_startups_begin;
p += options.max_startups_rate;
- r = arc4random() % 100;
+ r = arc4random_uniform(100);
debug("drop_connection: p %d, r %d", p, r);
return (r < p) ? 1 : 0;
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"
+"usage: sshd [-46DdeiqTt] [-b bits] [-C connection_spec] [-f config_file]\n"
+" [-g login_grace_time] [-h host_key_file] [-k key_gen_time]\n"
+" [-o option] [-p port] [-u len]\n"
);
exit(1);
}
debug3("%s: done", __func__);
}
+/* Accept a connection from inetd */
+static void
+server_accept_inetd(int *sock_in, int *sock_out)
+{
+ 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
+ * 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);
+}
+
+/*
+ * Listen for TCP connections
+ */
+static void
+server_listen(void)
+{
+ int ret, listen_sock, on = 1;
+ struct addrinfo *ai;
+ char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+
+ for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
+ if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
+ continue;
+ if (num_listen_socks >= MAX_LISTEN_SOCKS)
+ fatal("Too many listen sockets. "
+ "Enlarge MAX_LISTEN_SOCKS");
+ if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
+ ntop, sizeof(ntop), strport, sizeof(strport),
+ NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
+ error("getnameinfo failed: %.100s",
+ ssh_gai_strerror(ret));
+ continue;
+ }
+ /* Create socket for listening. */
+ listen_sock = socket(ai->ai_family, ai->ai_socktype,
+ ai->ai_protocol);
+ if (listen_sock < 0) {
+ /* kernel may not support ipv6 */
+ verbose("socket: %.100s", strerror(errno));
+ continue;
+ }
+ if (set_nonblock(listen_sock) == -1) {
+ close(listen_sock);
+ continue;
+ }
+ /*
+ * Set socket options.
+ * Allow local port reuse in TIME_WAIT.
+ */
+ if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
+ &on, sizeof(on)) == -1)
+ error("setsockopt SO_REUSEADDR: %s", strerror(errno));
+
+ /* Only communicate in IPv6 over AF_INET6 sockets. */
+ if (ai->ai_family == AF_INET6)
+ sock_set_v6only(listen_sock);
+
+ debug("Bind to port %s on %s.", strport, ntop);
+
+ /* Bind the socket to the desired port. */
+ if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+ error("Bind to port %s on %s failed: %.200s.",
+ strport, ntop, strerror(errno));
+ close(listen_sock);
+ continue;
+ }
+ listen_socks[num_listen_socks] = listen_sock;
+ 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);
+ }
+ freeaddrinfo(options.listen_addrs);
+
+ if (!num_listen_socks)
+ fatal("Cannot bind any address.");
+}
+
+/*
+ * The main TCP accept loop. Note that, for the non-debug case, returns
+ * from this function are in a forked subprocess.
+ */
+static void
+server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
+{
+ fd_set *fdset;
+ int i, j, ret, maxfd;
+ int key_used = 0, startups = 0;
+ int startup_p[2] = { -1 , -1 };
+ struct sockaddr_storage from;
+ socklen_t fromlen;
+ pid_t pid;
+
+ /* setup fd set for accept */
+ fdset = NULL;
+ maxfd = 0;
+ for (i = 0; i < num_listen_socks; i++)
+ if (listen_socks[i] > maxfd)
+ maxfd = listen_socks[i];
+ /* pipes connected to unauthenticated childs */
+ startup_pipes = xcalloc(options.max_startups, sizeof(int));
+ for (i = 0; i < options.max_startups; i++)
+ startup_pipes[i] = -1;
+
+ /*
+ * Stay listening for connections until the system crashes or
+ * the daemon is killed with a signal.
+ */
+ for (;;) {
+ if (received_sighup)
+ sighup_restart();
+ if (fdset != NULL)
+ xfree(fdset);
+ 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);
+ for (i = 0; i < options.max_startups; i++)
+ if (startup_pipes[i] != -1)
+ FD_SET(startup_pipes[i], fdset);
+
+ /* Wait in select until there is a connection. */
+ ret = select(maxfd+1, fdset, NULL, NULL, NULL);
+ if (ret < 0 && errno != EINTR)
+ error("select: %.100s", strerror(errno));
+ if (received_sigterm) {
+ logit("Received signal %d; terminating.",
+ (int) received_sigterm);
+ close_listen_socks();
+ unlink(options.pid_file);
+ exit(255);
+ }
+ if (key_used && key_do_regen) {
+ generate_ephemeral_server_key();
+ key_used = 0;
+ key_do_regen = 0;
+ }
+ if (ret < 0)
+ continue;
+
+ for (i = 0; i < options.max_startups; i++)
+ if (startup_pipes[i] != -1 &&
+ FD_ISSET(startup_pipes[i], fdset)) {
+ /*
+ * the read end of the pipe is ready
+ * if the child has closed the pipe
+ * after successful authentication
+ * or if the child has died
+ */
+ close(startup_pipes[i]);
+ startup_pipes[i] = -1;
+ startups--;
+ }
+ for (i = 0; i < num_listen_socks; i++) {
+ if (!FD_ISSET(listen_socks[i], fdset))
+ continue;
+ fromlen = sizeof(from);
+ *newsock = accept(listen_socks[i],
+ (struct sockaddr *)&from, &fromlen);
+ if (*newsock < 0) {
+ if (errno != EINTR && errno != EAGAIN &&
+ errno != EWOULDBLOCK)
+ error("accept: %.100s", strerror(errno));
+ continue;
+ }
+ if (unset_nonblock(*newsock) == -1) {
+ close(*newsock);
+ continue;
+ }
+ if (drop_connection(startups) == 1) {
+ debug("drop connection #%d", startups);
+ close(*newsock);
+ continue;
+ }
+ if (pipe(startup_p) == -1) {
+ close(*newsock);
+ 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];
+ if (maxfd < startup_p[0])
+ maxfd = startup_p[0];
+ startups++;
+ break;
+ }
+
+ /*
+ * Got connection. Fork a child to handle it, unless
+ * we are in debugging mode.
+ */
+ if (debug_flag) {
+ /*
+ * In debugging mode. Close the listening
+ * socket, and start processing the
+ * connection without forking.
+ */
+ debug("Server will not fork when running in debugging mode.");
+ 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;
+ }
+
+ /*
+ * Normal production daemon. Fork, and have
+ * the child process the connection. The
+ * parent continues listening.
+ */
+ platform_pre_fork();
+ 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
+ * the connection.
+ */
+ platform_post_fork_child();
+ startup_pipe = startup_p[1];
+ close_startup_pipes();
+ close_listen_socks();
+ *sock_in = *newsock;
+ *sock_out = *newsock;
+ log_init(__progname,
+ options.log_level,
+ options.log_facility,
+ log_stderr);
+ if (rexec_flag)
+ close(config_s[0]);
+ break;
+ }
+
+ /* Parent. Stay in the loop. */
+ platform_post_fork_parent(pid);
+ if (pid < 0)
+ error("fork: %.100s", strerror(errno));
+ else
+ debug("Forked child %ld.", (long)pid);
+
+ close(startup_p[1]);
+
+ 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. */
+ signal(SIGALRM, key_regeneration_alarm);
+ alarm(options.key_regeneration_time);
+ key_used = 1;
+ }
+
+ close(*newsock);
+
+ /*
+ * Ensure that our random state differs
+ * from that of the child
+ */
+ arc4random_stir();
+ }
+
+ /* child process check (or debug mode) */
+ if (num_listen_socks < 0)
+ break;
+ }
+}
+
+
/*
* Main program for the daemon.
*/
{
extern char *optarg;
extern int optind;
- int opt, j, i, fdsetsz, on = 1;
+ int opt, i, on = 1;
int sock_in = -1, sock_out = -1, newsock = -1;
- pid_t pid;
- socklen_t fromlen;
- fd_set *fdset;
- struct sockaddr_storage from;
const char *remote_ip;
+ char *test_user = NULL, *test_host = NULL, *test_addr = NULL;
int remote_port;
- FILE *f;
- struct addrinfo *ai;
- char ntop[NI_MAXHOST], strport[NI_MAXSERV];
- char *line;
- int listen_sock, maxfd;
- int startup_p[2] = { -1 , -1 }, config_s[2] = { -1 , -1 };
- int startups = 0;
+ char *line, *p, *cp;
+ int config_s[2] = { -1 , -1 };
+ u_int64_t ibytes, obytes;
+ mode_t new_umask;
Key *key;
Authctxt *authctxt;
- int ret, key_used = 0;
- Buffer cfg;
#ifdef HAVE_SECUREWARE
(void)set_auth_parameters(ac, av);
/* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
saved_argc = ac;
rexec_argc = ac;
- saved_argv = xmalloc(sizeof(*saved_argv) * (ac + 1));
+ saved_argv = xcalloc(ac + 1, sizeof(*saved_argv));
for (i = 0; i < ac; i++)
saved_argv[i] = xstrdup(av[i]);
saved_argv[i] = NULL;
initialize_server_options(&options);
/* Parse command-line arguments. */
- while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqrtQR46")) != -1) {
+ while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:C:dDeiqrtQRT46")) != -1) {
switch (opt) {
case '4':
options.address_family = AF_INET;
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;
exit(1);
}
options.ports[options.num_ports++] = a2port(optarg);
- if (options.ports[options.num_ports-1] == 0) {
+ if (options.ports[options.num_ports-1] <= 0) {
fprintf(stderr, "Bad port number.\n");
exit(1);
}
fprintf(stderr, "too many host keys.\n");
exit(1);
}
- options.host_key_files[options.num_host_key_files++] = optarg;
+ options.host_key_files[options.num_host_key_files++] =
+ derelativise_path(optarg);
break;
case 't':
test_flag = 1;
break;
+ case 'T':
+ test_flag = 2;
+ break;
+ case 'C':
+ cp = optarg;
+ while ((p = strsep(&cp, ",")) && *p != '\0') {
+ if (strncmp(p, "addr=", 5) == 0)
+ test_addr = xstrdup(p + 5);
+ else if (strncmp(p, "host=", 5) == 0)
+ test_host = xstrdup(p + 5);
+ else if (strncmp(p, "user=", 5) == 0)
+ test_user = xstrdup(p + 5);
+ else {
+ fprintf(stderr, "Invalid test "
+ "mode specification %s\n", p);
+ exit(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);
case 'o':
line = xstrdup(optarg);
if (process_server_config_line(&options, line,
- "command-line", 0) != 0)
+ "command-line", 0, NULL, NULL, NULL, NULL) != 0)
exit(1);
xfree(line);
break;
}
if (rexeced_flag || inetd_flag)
rexec_flag = 0;
- if (rexec_flag && (av[0] == NULL || *av[0] != '/'))
+ if (!test_flag && (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);
sensitive_data.have_ssh1_key = 0;
sensitive_data.have_ssh2_key = 0;
+ /*
+ * If we're doing an extended config test, make sure we have all of
+ * the parameters we need. If we're not doing an extended test,
+ * do not silently ignore connection test params.
+ */
+ if (test_flag >= 2 &&
+ (test_user != NULL || test_host != NULL || test_addr != NULL)
+ && (test_user == NULL || test_host == NULL || test_addr == NULL))
+ fatal("user, host and addr are all required when testing "
+ "Match configs");
+ if (test_flag < 2 && (test_user != NULL || test_host != NULL ||
+ test_addr != NULL))
+ fatal("Config test connection parameter (-C) provided without "
+ "test mode (-T)");
+
/* Fetch our configuration */
buffer_init(&cfg);
if (rexeced_flag)
else
load_server_config(config_file_name, &cfg);
- parse_server_config(&options,
- rexeced_flag ? "rexec" : config_file_name, &cfg);
-
- if (!rexec_flag)
- buffer_free(&cfg);
+ parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
+ &cfg, NULL, NULL, NULL);
seed_rng();
/* Fill in default values for those options not explicitly set. */
fill_default_server_options(&options);
+ /* challenge-response is implemented via keyboard interactive */
+ if (options.challenge_response_authentication)
+ options.kbd_interactive_authentication = 1;
+
/* set default channel AF */
channel_set_af(options.address_family);
debug("sshd version %.100s", SSH_RELEASE);
+ /* Store privilege separation user for later use if required. */
+ if ((privsep_pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) {
+ if (use_privsep || options.kerberos_authentication)
+ fatal("Privilege separation user %s does not exist",
+ SSH_PRIVSEP_USER);
+ } else {
+ memset(privsep_pw->pw_passwd, 0, strlen(privsep_pw->pw_passwd));
+ privsep_pw = pwcopy(privsep_pw);
+ xfree(privsep_pw->pw_passwd);
+ privsep_pw->pw_passwd = xstrdup("*");
+ }
+ endpwent();
+
/* 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;
}
if (use_privsep) {
- struct passwd *pw;
struct stat st;
- if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
- fatal("Privilege separation user %s does not exist",
- SSH_PRIVSEP_USER);
if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
(S_ISDIR(st.st_mode) == 0))
fatal("Missing privilege separation directory: %s",
"world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
}
+ if (test_flag > 1) {
+ if (test_user != NULL && test_addr != NULL && test_host != NULL)
+ parse_server_match_config(&options, test_user,
+ test_host, test_addr);
+ dump_config(&options);
+ }
+
/* Configuration looks good, so exit if in test mode. */
if (test_flag)
exit(0);
debug("setgroups() failed: %.200s", strerror(errno));
if (rexec_flag) {
- rexec_argv = xmalloc(sizeof(char *) * (rexec_argc + 2));
+ 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 + 1] = NULL;
}
+ /* Ensure that umask disallows at least group and world write */
+ new_umask = umask(0077) | 0022;
+ (void) umask(new_umask);
+
/* Initialize the log (it is reinitialized below in case we forked). */
if (debug_flag && (!inetd_flag || rexeced_flag))
log_stderr = 1;
/* ignore SIGPIPE */
signal(SIGPIPE, SIG_IGN);
- /* Start listening for a socket, unless started from inetd. */
+ /* Get a connection, either from inetd or a listening TCP socket */
if (inetd_flag) {
- 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
- * 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) &&
- sensitive_data.server_key == NULL)
- generate_ephemeral_server_key();
+ server_accept_inetd(&sock_in, &sock_out);
} else {
- for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
- if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
- continue;
- if (num_listen_socks >= MAX_LISTEN_SOCKS)
- fatal("Too many listen sockets. "
- "Enlarge MAX_LISTEN_SOCKS");
- if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
- ntop, sizeof(ntop), strport, sizeof(strport),
- NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
- error("getnameinfo failed: %.100s",
- (ret != EAI_SYSTEM) ? gai_strerror(ret) :
- strerror(errno));
- continue;
- }
- /* Create socket for listening. */
- listen_sock = socket(ai->ai_family, ai->ai_socktype,
- ai->ai_protocol);
- if (listen_sock < 0) {
- /* kernel may not support ipv6 */
- verbose("socket: %.100s", strerror(errno));
- continue;
- }
- if (set_nonblock(listen_sock) == -1) {
- close(listen_sock);
- continue;
- }
- /*
- * Set socket options.
- * Allow local port reuse in TIME_WAIT.
- */
- if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
- &on, sizeof(on)) == -1)
- error("setsockopt SO_REUSEADDR: %s", strerror(errno));
-
- debug("Bind to port %s on %s.", strport, ntop);
-
- /* Bind the socket to the desired port. */
- if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
- if (!ai->ai_next)
- error("Bind to port %s on %s failed: %.200s.",
- strport, ntop, strerror(errno));
- close(listen_sock);
- continue;
- }
- listen_socks[num_listen_socks] = listen_sock;
- 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);
- }
- freeaddrinfo(options.listen_addrs);
-
- if (!num_listen_socks)
- fatal("Cannot bind any address.");
+ platform_pre_listen();
+ server_listen();
if (options.protocol & SSH_PROTO_1)
generate_ephemeral_server_key();
- /*
- * Arrange to restart on SIGHUP. The handler needs
- * listen_sock.
- */
signal(SIGHUP, sighup_handler);
-
+ signal(SIGCHLD, main_sigchld_handler);
signal(SIGTERM, sigterm_handler);
signal(SIGQUIT, sigterm_handler);
- /* Arrange SIGCHLD to be caught. */
- signal(SIGCHLD, main_sigchld_handler);
-
- /* Write out the pid file after the sigterm handler is setup */
+ /*
+ * Write out the pid file after the sigterm handler
+ * is setup and the listen sockets are bound
+ */
if (!debug_flag) {
- /*
- * Record our pid in /var/run/sshd.pid to make it
- * easier to kill the correct sshd. We don't want to
- * do this before the bind above because the bind will
- * fail if there already is a daemon, and this will
- * overwrite any old pid in the file.
- */
- f = fopen(options.pid_file, "wb");
+ FILE *f = fopen(options.pid_file, "w");
+
if (f == NULL) {
error("Couldn't create pid file \"%s\": %s",
options.pid_file, strerror(errno));
}
}
- /* setup fd set for listen */
- fdset = NULL;
- maxfd = 0;
- for (i = 0; i < num_listen_socks; i++)
- if (listen_socks[i] > maxfd)
- maxfd = listen_socks[i];
- /* pipes connected to unauthenticated childs */
- startup_pipes = xmalloc(options.max_startups * sizeof(int));
- for (i = 0; i < options.max_startups; i++)
- startup_pipes[i] = -1;
-
- /*
- * Stay listening for connections until the system crashes or
- * the daemon is killed with a signal.
- */
- for (;;) {
- if (received_sighup)
- sighup_restart();
- if (fdset != NULL)
- xfree(fdset);
- fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
- fdset = (fd_set *)xmalloc(fdsetsz);
- memset(fdset, 0, fdsetsz);
-
- for (i = 0; i < num_listen_socks; i++)
- FD_SET(listen_socks[i], fdset);
- for (i = 0; i < options.max_startups; i++)
- if (startup_pipes[i] != -1)
- FD_SET(startup_pipes[i], fdset);
-
- /* Wait in select until there is a connection. */
- ret = select(maxfd+1, fdset, NULL, NULL, NULL);
- if (ret < 0 && errno != EINTR)
- error("select: %.100s", strerror(errno));
- if (received_sigterm) {
- logit("Received signal %d; terminating.",
- (int) received_sigterm);
- close_listen_socks();
- unlink(options.pid_file);
- exit(255);
- }
- if (key_used && key_do_regen) {
- generate_ephemeral_server_key();
- key_used = 0;
- key_do_regen = 0;
- }
- if (ret < 0)
- continue;
-
- for (i = 0; i < options.max_startups; i++)
- if (startup_pipes[i] != -1 &&
- FD_ISSET(startup_pipes[i], fdset)) {
- /*
- * the read end of the pipe is ready
- * if the child has closed the pipe
- * after successful authentication
- * or if the child has died
- */
- close(startup_pipes[i]);
- startup_pipes[i] = -1;
- startups--;
- }
- for (i = 0; i < num_listen_socks; i++) {
- if (!FD_ISSET(listen_socks[i], fdset))
- continue;
- fromlen = sizeof(from);
- newsock = accept(listen_socks[i], (struct sockaddr *)&from,
- &fromlen);
- if (newsock < 0) {
- if (errno != EINTR && errno != EWOULDBLOCK)
- error("accept: %.100s", strerror(errno));
- continue;
- }
- if (unset_nonblock(newsock) == -1) {
- close(newsock);
- continue;
- }
- if (drop_connection(startups) == 1) {
- debug("drop connection #%d", startups);
- close(newsock);
- continue;
- }
- if (pipe(startup_p) == -1) {
- close(newsock);
- 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];
- if (maxfd < startup_p[0])
- maxfd = startup_p[0];
- startups++;
- break;
- }
-
- /*
- * Got connection. Fork a child to handle it, unless
- * we are in debugging mode.
- */
- if (debug_flag) {
- /*
- * In debugging mode. Close the listening
- * socket, and start processing the
- * connection without forking.
- */
- debug("Server will not fork when running in debugging mode.");
- 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 {
- /*
- * Normal production daemon. Fork, and have
- * the child process the connection. The
- * parent continues listening.
- */
- 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
- * the connection.
- */
- startup_pipe = startup_p[1];
- close_startup_pipes();
- close_listen_socks();
- sock_in = newsock;
- sock_out = newsock;
- log_init(__progname, options.log_level, options.log_facility, log_stderr);
- if (rexec_flag)
- close(config_s[0]);
- break;
- }
- }
-
- /* Parent. Stay in the loop. */
- if (pid < 0)
- error("fork: %.100s", strerror(errno));
- else
- debug("Forked child %ld.", (long)pid);
-
- close(startup_p[1]);
-
- 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. */
- 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) */
- if (num_listen_socks < 0)
- break;
- }
+ /* Accept a connection and return in a forked child */
+ server_accept_loop(&sock_in, &sock_out,
+ &newsock, config_s);
}
/* This is the child processing a new connection. */
sock_in, sock_out, newsock, startup_pipe, config_s[0]);
}
+ /* Executed child processes don't need these. */
+ fcntl(sock_out, F_SETFD, FD_CLOEXEC);
+ fcntl(sock_in, F_SETFD, FD_CLOEXEC);
+
/*
* 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
* 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);
+ (void) get_canonical_hostname(0);
+ /*
+ * The rest of the code depends on the fact that
+ * get_remote_ipaddr() caches the remote ip, even if
+ * the socket goes away.
+ */
+ remote_ip = get_remote_ipaddr();
#ifdef SSH_AUDIT_EVENTS
audit_connection_from(remote_ip, remote_port);
#endif
#ifdef LIBWRAP
+ allow_severity = options.log_facility|LOG_INFO;
+ deny_severity = options.log_facility|LOG_WARNING;
/* Check whether logins are denied from this host. */
if (packet_connection_is_on_socket()) {
struct request_info req;
sshd_exchange_identification(sock_in, sock_out);
+ /* In inetd mode, generate ephemeral key only for proto 1 connections */
+ if (!compat20 && inetd_flag && sensitive_data.server_key == NULL)
+ generate_ephemeral_server_key();
+
packet_set_nonblocking();
/* allocate authentication context */
- authctxt = xmalloc(sizeof(*authctxt));
- memset(authctxt, 0, sizeof(*authctxt));
+ authctxt = xcalloc(1, sizeof(*authctxt));
authctxt->loginmsg = &loginmsg;
*/
alarm(0);
signal(SIGALRM, SIG_DFL);
+ authctxt->authenticated = 1;
if (startup_pipe != -1) {
close(startup_pipe);
startup_pipe = -1;
audit_event(SSH_AUTH_SUCCESS);
#endif
+#ifdef GSSAPI
+ if (options.gss_authentication) {
+ temporarily_use_uid(authctxt->pw);
+ ssh_gssapi_storecreds();
+ restore_uid();
+ }
+#endif
+#ifdef USE_PAM
+ if (options.use_pam) {
+ do_pam_setcred(1);
+ do_pam_session();
+ }
+#endif
+
/*
* In privilege separation, we fork another child and prepare
* file descriptor passing.
destroy_sensitive_data();
}
+ packet_set_timeout(options.client_alive_interval,
+ options.client_alive_count_max);
+
/* Start session. */
do_authenticated(authctxt);
/* The connection has been terminated. */
- verbose("Closing connection to %.100s", remote_ip);
+ packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
+ packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
+ verbose("Transferred: sent %llu, received %llu bytes", obytes, ibytes);
+
+ verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
#ifdef USE_PAM
if (options.use_pam)
{
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),
u_char session_key[SSH_SESSION_KEY_LENGTH];
u_char cookie[8];
u_int cipher_type, auth_mask, protocol_flags;
- u_int32_t rnd = 0;
/*
* Generate check bytes that the client must send back in the user
* cookie. This only affects rhosts authentication, and this is one
* of the reasons why it is inherently insecure.
*/
- for (i = 0; i < 8; i++) {
- if (i % 4 == 0)
- rnd = arc4random();
- cookie[i] = rnd & 0xff;
- rnd >>= 8;
- }
+ arc4random_buf(cookie, sizeof(cookie));
/*
* Send our public key. We include in the packet 64 bits of random
* key is in the highest bits.
*/
if (!rsafail) {
- BN_mask_bits(session_key_int, sizeof(session_key) * 8);
+ (void) BN_mask_bits(session_key_int, sizeof(session_key) * 8);
len = BN_num_bytes(session_key_int);
if (len < 0 || (u_int)len > sizeof(session_key)) {
- error("do_connection: bad session key len from %s: "
+ error("do_ssh1_kex: bad session key len from %s: "
"session_key_int %d > sizeof(session_key) %lu",
get_remote_ipaddr(), len, (u_long)sizeof(session_key));
rsafail++;
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 */
andersk / openssh.git / blobdiff