1 files changed, 126 insertions, 44 deletions

diff --git a/sshd.c b/sshd.c
index 11571c010..60b2aaf73 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.537 2019/06/28 13:35:04 deraadt Exp $ */
+/* $OpenBSD: sshd.c,v 1.549 2020/01/31 23:13:04 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -122,6 +122,7 @@
 #include "auth-options.h"
 #include "version.h"
 #include "ssherr.h"
+#include "sk-api.h"
 
 /* Re-exec fds */
 #define REEXEC_DEVCRYPTO_RESERVED_FD    (STDERR_FILENO + 1)
@@ -250,6 +251,9 @@ struct sshauthopt *auth_opts = NULL;
 /* sshd_config buffer */
 struct sshbuf *cfg;
 
+/* Included files from the configuration file */
+struct include_list includes = TAILQ_HEAD_INITIALIZER(includes);
+
 /* message to be displayed after login */
 struct sshbuf *loginmsg;
 
@@ -261,6 +265,8 @@ void destroy_sensitive_data(void);
 void demote_sensitive_data(void);
 static void do_ssh2_kex(struct ssh *);
 
+static char *listener_proctitle;
+
 /*
  * Close all listening sockets
  */
@@ -295,10 +301,7 @@ close_startup_pipes(void)
 static void
 sighup_handler(int sig)
 {
-        int save_errno = errno;
-
         received_sighup = 1;
-        errno = save_errno;
 }
 
 /*
@@ -315,7 +318,7 @@ sighup_restart(void)
         close_listen_socks();
         close_startup_pipes();
         alarm(0);  /* alarm timer persists across exec */
-        signal(SIGHUP, SIG_IGN); /* will be restored after exec */
+        ssh_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));
@@ -344,6 +347,8 @@ main_sigchld_handler(int sig)
         pid_t pid;
         int status;
 
+        debug("main_sigchld_handler: %s", strsignal(sig));
+
         while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
             (pid == -1 && errno == EINTR))
                 ;
@@ -365,7 +370,7 @@ grace_alarm_handler(int sig)
          * keys command helpers.
          */
         if (getpgid(0) == getpid()) {
-                signal(SIGTERM, SIG_IGN);
+                ssh_signal(SIGTERM, SIG_IGN);
                 kill(0, SIGTERM);
         }
 
@@ -635,6 +640,8 @@ list_hostkey_types(void)
                 case KEY_DSA:
                 case KEY_ECDSA:
                 case KEY_ED25519:
+                case KEY_ECDSA_SK:
+                case KEY_ED25519_SK:
                 case KEY_XMSS:
                         append_hostkey_type(b, sshkey_ssh_name(key));
                         break;
@@ -654,6 +661,8 @@ list_hostkey_types(void)
                 case KEY_DSA_CERT:
                 case KEY_ECDSA_CERT:
                 case KEY_ED25519_CERT:
+                case KEY_ECDSA_SK_CERT:
+                case KEY_ED25519_SK_CERT:
                 case KEY_XMSS_CERT:
                         append_hostkey_type(b, sshkey_ssh_name(key));
                         break;
@@ -678,6 +687,8 @@ get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh)
                 case KEY_DSA_CERT:
                 case KEY_ECDSA_CERT:
                 case KEY_ED25519_CERT:
+                case KEY_ECDSA_SK_CERT:
+                case KEY_ED25519_SK_CERT:
                 case KEY_XMSS_CERT:
                         key = sensitive_data.host_certificates[i];
                         break;
@@ -687,10 +698,20 @@ get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh)
                                 key = sensitive_data.host_pubkeys[i];
                         break;
                 }
-                if (key != NULL && key->type == type &&
-                    (key->type != KEY_ECDSA || key->ecdsa_nid == nid))
+                if (key == NULL || key->type != type)
+                        continue;
+                switch (type) {
+                case KEY_ECDSA:
+                case KEY_ECDSA_SK:
+                case KEY_ECDSA_CERT:
+                case KEY_ECDSA_SK_CERT:
+                        if (key->ecdsa_nid != nid)
+                                continue;
+                        /* FALLTHROUGH */
+                default:
                         return need_private ?
                             sensitive_data.host_keys[i] : key;
+                }
         }
         return NULL;
 }
@@ -852,30 +873,45 @@ usage(void)
 static void
 send_rexec_state(int fd, struct sshbuf *conf)
 {
-        struct sshbuf *m;
+        struct sshbuf *m = NULL, *inc = NULL;
+        struct include_item *item = NULL;
         int r;
 
         debug3("%s: entering fd = %d config len %zu", __func__, fd,
             sshbuf_len(conf));
 
+        if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
+                fatal("%s: sshbuf_new failed", __func__);
+
+        /* pack includes into a string */
+        TAILQ_FOREACH(item, &includes, entry) {
+                if ((r = sshbuf_put_cstring(inc, item->selector)) != 0 ||
+                    (r = sshbuf_put_cstring(inc, item->filename)) != 0 ||
+                    (r = sshbuf_put_stringb(inc, item->contents)) != 0)
+                        fatal("%s: buffer error: %s", __func__, ssh_err(r));
+        }
+
         /*
          * Protocol from reexec master to child:
          *      string  configuration
-         *      string rngseed          (only if OpenSSL is not self-seeded)
+         *      string  included_files[] {
+         *              string  selector
+         *              string  filename
+         *              string  contents
+         *      }
+         *      string  rng_seed (if required)
          */
-        if ((m = sshbuf_new()) == NULL)
-                fatal("%s: sshbuf_new failed", __func__);
-        if ((r = sshbuf_put_stringb(m, conf)) != 0)
+        if ((r = sshbuf_put_stringb(m, conf)) != 0 ||
+            (r = sshbuf_put_stringb(m, inc)) != 0)
                 fatal("%s: buffer error: %s", __func__, ssh_err(r));
-
 #if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY)
         rexec_send_rng_seed(m);
 #endif
-
         if (ssh_msg_send(fd, 0, m) == -1)
                 fatal("%s: ssh_msg_send failed", __func__);
 
         sshbuf_free(m);
+        sshbuf_free(inc);
 
         debug3("%s: done", __func__);
 }
@@ -883,14 +919,15 @@ send_rexec_state(int fd, struct sshbuf *conf)
 static void
 recv_rexec_state(int fd, struct sshbuf *conf)
 {
-        struct sshbuf *m;
+        struct sshbuf *m, *inc;
         u_char *cp, ver;
         size_t len;
         int r;
+        struct include_item *item;
 
         debug3("%s: entering fd = %d", __func__, fd);
 
-        if ((m = sshbuf_new()) == NULL)
+        if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
                 fatal("%s: sshbuf_new failed", __func__);
         if (ssh_msg_recv(fd, m) == -1)
                 fatal("%s: ssh_msg_recv failed", __func__);
@@ -898,14 +935,28 @@ recv_rexec_state(int fd, struct sshbuf *conf)
                 fatal("%s: buffer error: %s", __func__, ssh_err(r));
         if (ver != 0)
                 fatal("%s: rexec version mismatch", __func__);
-        if ((r = sshbuf_get_string(m, &cp, &len)) != 0)
-                fatal("%s: buffer error: %s", __func__, ssh_err(r));
-        if (conf != NULL && (r = sshbuf_put(conf, cp, len)))
+        if ((r = sshbuf_get_string(m, &cp, &len)) != 0 ||
+            (r = sshbuf_get_stringb(m, inc)) != 0)
                 fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
 #if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY)
         rexec_recv_rng_seed(m);
 #endif
 
+        if (conf != NULL && (r = sshbuf_put(conf, cp, len)))
+                fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+        while (sshbuf_len(inc) != 0) {
+                item = xcalloc(1, sizeof(*item));
+                if ((item->contents = sshbuf_new()) == NULL)
+                        fatal("%s: sshbuf_new failed", __func__);
+                if ((r = sshbuf_get_cstring(inc, &item->selector, NULL)) != 0 ||
+                    (r = sshbuf_get_cstring(inc, &item->filename, NULL)) != 0 ||
+                    (r = sshbuf_get_stringb(inc, item->contents)) != 0)
+                        fatal("%s: buffer error: %s", __func__, ssh_err(r));
+                TAILQ_INSERT_TAIL(&includes, item, entry);
+        }
+
         free(cp);
         sshbuf_free(m);
 
@@ -1045,7 +1096,7 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
 {
         fd_set *fdset;
         int i, j, ret, maxfd;
-        int startups = 0, listening = 0, lameduck = 0;
+        int ostartups = -1, startups = 0, listening = 0, lameduck = 0;
         int startup_p[2] = { -1 , -1 };
         char c = 0;
         struct sockaddr_storage from;
@@ -1070,6 +1121,12 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
          * the daemon is killed with a signal.
          */
         for (;;) {
+                if (ostartups != startups) {
+                        setproctitle("%s [listener] %d of %d-%d startups",
+                            listener_proctitle, startups,
+                            options.max_startups_begin, options.max_startups);
+                        ostartups = startups;
+                }
                 if (received_sighup) {
                         if (!lameduck) {
                                 debug("Received SIGHUP; waiting for children");
@@ -1157,6 +1214,7 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
                         if (drop_connection(startups) == 1) {
                                 char *laddr = get_local_ipaddr(*newsock);
                                 char *raddr = get_peer_ipaddr(*newsock);
+                                char msg[] = "Exceeded MaxStartups\r\n";
 
                                 verbose("drop connection #%d from [%s]:%d "
                                     "on [%s]:%d past MaxStartups", startups,
@@ -1164,6 +1222,8 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
                                     laddr, get_local_port(*newsock));
                                 free(laddr);
                                 free(raddr);
+                                /* best-effort notification to client */
+                                (void)write(*newsock, msg, strlen(msg));
                                 close(*newsock);
                                 continue;
                         }
@@ -1410,6 +1470,17 @@ accumulate_host_timing_secret(struct sshbuf *server_cfg,
         sshbuf_free(buf);
 }
 
+static char *
+prepare_proctitle(int ac, char **av)
+{
+        char *ret = NULL;
+        int i;
+
+        for (i = 0; i < ac; i++)
+                xextendf(&ret, " ", "%s", av[i]);
+        return ret;
+}
+
 /*
  * Main program for the daemon.
  */
@@ -1562,7 +1633,7 @@ main(int ac, char **av)
                 case 'o':
                         line = xstrdup(optarg);
                         if (process_server_config_line(&options, line,
-                            "command-line", 0, NULL, NULL) != 0)
+                            "command-line", 0, NULL, NULL, &includes) != 0)
                                 exit(1);
                         free(line);
                         break;
@@ -1593,7 +1664,7 @@ main(int ac, char **av)
             SYSLOG_LEVEL_INFO : options.log_level,
             options.log_facility == SYSLOG_FACILITY_NOT_SET ?
             SYSLOG_FACILITY_AUTH : options.log_facility,
-            log_stderr || !inetd_flag);
+            log_stderr || !inetd_flag || debug_flag);
 
         /*
          * Unset KRB5CCNAME, otherwise the user's session may inherit it from
@@ -1626,12 +1697,11 @@ main(int ac, char **av)
                          */
                         (void)atomicio(vwrite, startup_pipe, "\0", 1);
                 }
-        }
-        else if (strcasecmp(config_file_name, "none") != 0)
+        } else if (strcasecmp(config_file_name, "none") != 0)
                 load_server_config(config_file_name, cfg);
 
         parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
-            cfg, NULL);
+            cfg, &includes, NULL);
 
         /* Fill in default values for those options not explicitly set. */
         fill_default_server_options(&options);
@@ -1723,7 +1793,14 @@ main(int ac, char **av)
                     &key, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR)
                         do_log2(ll, "Unable to load host key \"%s\": %s",
                             options.host_key_files[i], ssh_err(r));
-                if (r == 0 && (r = sshkey_shield_private(key)) != 0) {
+                if (sshkey_is_sk(key) &&
+                    key->sk_flags & SSH_SK_USER_PRESENCE_REQD) {
+                        debug("host key %s requires user presence, ignoring",
+                            options.host_key_files[i]);
+                        key->sk_flags &= ~SSH_SK_USER_PRESENCE_REQD;
+                }
+                if (r == 0 && key != NULL &&
+                    (r = sshkey_shield_private(key)) != 0) {
                         do_log2(ll, "Unable to shield host key \"%s\": %s",
                             options.host_key_files[i], ssh_err(r));
                         sshkey_free(key);
@@ -1760,6 +1837,8 @@ main(int ac, char **av)
                 case KEY_DSA:
                 case KEY_ECDSA:
                 case KEY_ED25519:
+                case KEY_ECDSA_SK:
+                case KEY_ED25519_SK:
                 case KEY_XMSS:
                         if (have_agent || key != NULL)
                                 sensitive_data.have_ssh2_key = 1;
@@ -1848,7 +1927,7 @@ main(int ac, char **av)
                 if (connection_info == NULL)
                         connection_info = get_connection_info(ssh, 0, 0);
                 connection_info->test = 1;
-                parse_server_match_config(&options, connection_info);
+                parse_server_match_config(&options, &includes, connection_info);
                 dump_config(&options);
         }
 
@@ -1877,6 +1956,7 @@ main(int ac, char **av)
                 rexec_argv[rexec_argc] = "-R";
                 rexec_argv[rexec_argc + 1] = NULL;
         }
+        listener_proctitle = prepare_proctitle(ac, av);
 
         /* Ensure that umask disallows at least group and world write */
         new_umask = umask(0077) | 0022;
@@ -1909,7 +1989,7 @@ main(int ac, char **av)
                 error("chdir(\"/\"): %s", strerror(errno));
 
         /* ignore SIGPIPE */
-        signal(SIGPIPE, SIG_IGN);
+        ssh_signal(SIGPIPE, SIG_IGN);
 
         /* Get a connection, either from inetd or a listening TCP socket */
         if (inetd_flag) {
@@ -1918,10 +1998,10 @@ main(int ac, char **av)
                 platform_pre_listen();
                 server_listen();
 
-                signal(SIGHUP, sighup_handler);
-                signal(SIGCHLD, main_sigchld_handler);
-                signal(SIGTERM, sigterm_handler);
-                signal(SIGQUIT, sigterm_handler);
+                ssh_signal(SIGHUP, sighup_handler);
+                ssh_signal(SIGCHLD, main_sigchld_handler);
+                ssh_signal(SIGTERM, sigterm_handler);
+                ssh_signal(SIGQUIT, sigterm_handler);
 
                 /*
                  * Write out the pid file after the sigterm handler
@@ -2011,12 +2091,12 @@ main(int ac, char **av)
          * will not restart on SIGHUP since it no longer makes sense.
          */
         alarm(0);
-        signal(SIGALRM, SIG_DFL);
-        signal(SIGHUP, SIG_DFL);
-        signal(SIGTERM, SIG_DFL);
-        signal(SIGQUIT, SIG_DFL);
-        signal(SIGCHLD, SIG_DFL);
-        signal(SIGINT, SIG_DFL);
+        ssh_signal(SIGALRM, SIG_DFL);
+        ssh_signal(SIGHUP, SIG_DFL);
+        ssh_signal(SIGTERM, SIG_DFL);
+        ssh_signal(SIGQUIT, SIG_DFL);
+        ssh_signal(SIGCHLD, SIG_DFL);
+        ssh_signal(SIGINT, SIG_DFL);
 
         /*
          * Register our connection.  This turns encryption off because we do
@@ -2077,7 +2157,7 @@ main(int ac, char **av)
          * mode; it is just annoying to have the server exit just when you
          * are about to discover the bug.
          */
-        signal(SIGALRM, grace_alarm_handler);
+        ssh_signal(SIGALRM, grace_alarm_handler);
         if (!debug_flag)
                 alarm(options.login_grace_time);
 
@@ -2135,7 +2215,7 @@ main(int ac, char **av)
          * authentication.
          */
         alarm(0);
-        signal(SIGALRM, SIG_DFL);
+        ssh_signal(SIGALRM, SIG_DFL);
         authctxt->authenticated = 1;
         if (startup_pipe != -1) {
                 close(startup_pipe);
@@ -2212,17 +2292,19 @@ sshd_hostkey_sign(struct ssh *ssh, struct sshkey *privkey,
         if (use_privsep) {
                 if (privkey) {
                         if (mm_sshkey_sign(ssh, privkey, signature, slenp,
-                            data, dlen, alg, ssh->compat) < 0)
+                            data, dlen, alg, options.sk_provider,
+                            ssh->compat) < 0)
                                 fatal("%s: privkey sign failed", __func__);
                 } else {
                         if (mm_sshkey_sign(ssh, pubkey, signature, slenp,
-                            data, dlen, alg, ssh->compat) < 0)
+                            data, dlen, alg, options.sk_provider,
+                            ssh->compat) < 0)
                                 fatal("%s: pubkey sign failed", __func__);
                 }
         } else {
                 if (privkey) {
                         if (sshkey_sign(privkey, signature, slenp, data, dlen,
-                            alg, ssh->compat) < 0)
+                            alg, options.sk_provider, ssh->compat) < 0)
                                 fatal("%s: privkey sign failed", __func__);
                 } else {
                         if ((r = ssh_agent_sign(auth_sock, pubkey,