]> andersk Git - openssh.git/blobdiff - sshd.c
- (dtucker) [packet.c] Remove in_systm.h since it's also in includes.h
[openssh.git] / sshd.c
diff --git a/sshd.c b/sshd.c
index 11d618d11163f9df05ff75ecc4b97f56d8ea561e..a206db2452a70a7d349d0fd41fe752b0adb4d51a 100644 (file)
--- a/sshd.c
+++ b/sshd.c
@@ -1,3 +1,4 @@
+/* $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 1.308 2005/02/08 22:24:57 dtucker 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>
@@ -246,6 +258,8 @@ close_startup_pipes(void)
  * the effect is to reread the configuration file (and to regenerate
  * the server key).
  */
+
+/*ARGSUSED*/
 static void
 sighup_handler(int sig)
 {
@@ -275,6 +289,7 @@ sighup_restart(void)
 /*
  * Generic signal handler for terminating signals in the master daemon.
  */
+/*ARGSUSED*/
 static void
 sigterm_handler(int sig)
 {
@@ -285,6 +300,7 @@ 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)
 {
@@ -303,6 +319,7 @@ 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)
 {
@@ -345,6 +362,7 @@ generate_ephemeral_server_key(void)
        arc4random_stir();
 }
 
+/*ARGSUSED*/
 static void
 key_regeneration_alarm(int sig)
 {
@@ -358,7 +376,8 @@ 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;
@@ -632,16 +651,8 @@ privsep_postauth(Authctxt *authctxt)
        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 */
@@ -668,8 +679,15 @@ privsep_postauth(Authctxt *authctxt)
        /* 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 *
@@ -793,6 +811,7 @@ send_rexec_state(int fd, Buffer *conf)
         *      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));
@@ -809,6 +828,10 @@ send_rexec_state(int fd, Buffer *conf)
        } 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__);
 
@@ -851,6 +874,11 @@ recv_rexec_state(int fd, Buffer *conf)
                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__);
@@ -864,7 +892,7 @@ main(int ac, char **av)
 {
        extern char *optarg;
        extern int optind;
-       int opt, 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;
@@ -907,6 +935,9 @@ main(int ac, char **av)
        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);
 
@@ -952,7 +983,8 @@ main(int ac, char **av)
                        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;
@@ -989,7 +1021,7 @@ main(int ac, char **av)
                        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);
@@ -1033,7 +1065,7 @@ main(int ac, char **av)
        /*
         * Unset KRB5CCNAME, otherwise the user's session may inherit it from
         * root's environment
-        */ 
+        */
        if (getenv("KRB5CCNAME") != NULL)
                unsetenv("KRB5CCNAME");
 
@@ -1044,8 +1076,6 @@ main(int ac, char **av)
        drop_cray_privs();
 #endif
 
-       seed_rng();
-
        sensitive_data.server_key = NULL;
        sensitive_data.ssh1_host_key = NULL;
        sensitive_data.have_ssh1_key = 0;
@@ -1064,6 +1094,8 @@ main(int ac, char **av)
        if (!rexec_flag)
                buffer_free(&cfg);
 
+       seed_rng();
+
        /* Fill in default values for those options not explicitly set. */
        fill_default_server_options(&options);
 
@@ -1079,7 +1111,7 @@ main(int ac, char **av)
        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;
@@ -1145,10 +1177,9 @@ main(int ac, char **av)
        }
 
        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) ||
@@ -1182,7 +1213,7 @@ main(int ac, char **av)
                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];
@@ -1310,10 +1341,10 @@ main(int ac, char **av)
                        num_listen_socks++;
 
                        /* Start listening on the port. */
-                       logit("Server listening on %s port %s.", ntop, strport);
                        if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
-                               fatal("listen: %.100s", strerror(errno));
-
+                               fatal("listen on [%s]:%s: %.100s",
+                                   ntop, strport, strerror(errno));
+                       logit("Server listening on %s port %s.", ntop, strport);
                }
                freeaddrinfo(options.listen_addrs);
 
@@ -1361,7 +1392,7 @@ main(int ac, char **av)
                        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;
 
@@ -1374,9 +1405,8 @@ main(int ac, char **av)
                                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);
@@ -1420,8 +1450,8 @@ main(int ac, char **av)
                                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));
@@ -1492,10 +1522,11 @@ main(int ac, char **av)
                                         */
                                        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];
@@ -1503,7 +1534,10 @@ main(int ac, char **av)
                                                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;
@@ -1524,7 +1558,10 @@ main(int ac, char **av)
                                        close(config_s[1]);
                                }
 
-                               /* Mark that the key has been used (it was "given" to the child). */
+                               /*
+                                * 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. */
@@ -1534,8 +1571,6 @@ main(int ac, char **av)
                                }
 
                                arc4random_stir();
-
-                               /* Close the new socket (the child is now taking care of it). */
                                close(newsock);
                        }
                        /* child process check (or debug mode) */
@@ -1615,20 +1650,28 @@ main(int ac, char **av)
        signal(SIGCHLD, SIG_DFL);
        signal(SIGINT, SIG_DFL);
 
-       /* Set SO_KEEPALIVE if requested. */
-       if (options.tcp_keep_alive &&
-           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));
 
-       remote_port = get_remote_port();
-       remote_ip = get_remote_ipaddr();
+       if ((remote_port = get_remote_port()) < 0) {
+               debug("get_remote_port failed");
+               cleanup_exit(255);
+       }
+
+       /*
+        * 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);
@@ -1654,10 +1697,10 @@ main(int ac, char **av)
        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.
         */
@@ -1670,8 +1713,9 @@ main(int ac, char **av)
        packet_set_nonblocking();
 
        /* allocate authentication context */
-       authctxt = xmalloc(sizeof(*authctxt));
-       memset(authctxt, 0, sizeof(*authctxt));
+       authctxt = xcalloc(1, sizeof(*authctxt));
+
+       authctxt->loginmsg = &loginmsg;
 
        /* XXX global for cleanup, access from other modules */
        the_authctxt = authctxt;
@@ -1702,6 +1746,17 @@ main(int ac, char **av)
        }
 
  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
@@ -1749,11 +1804,14 @@ ssh1_session_key(BIGNUM *session_key_int)
 {
        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),
@@ -1768,8 +1826,10 @@ ssh1_session_key(BIGNUM *session_key_int)
        } 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),
@@ -1896,7 +1956,7 @@ do_ssh1_kex(void)
        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));
@@ -1983,10 +2043,14 @@ do_ssh2_kex(void)
                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 */
@@ -1994,6 +2058,7 @@ do_ssh2_kex(void)
        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;
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