1 files changed, 118 insertions, 40 deletions

diff --git a/sshd.c b/sshd.c
index efa3f4c13..be3b3b8bb 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.351 2007/05/22 10:18:52 djm Exp $ */
+/* $OpenBSD: sshd.c,v 1.364 2008/07/10 18:08:11 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -54,6 +54,7 @@
 # include <sys/time.h>
 #endif
 #include "openbsd-compat/sys-tree.h"
+#include "openbsd-compat/sys-queue.h"
 #include <sys/wait.h>
 
 #include <errno.h>
@@ -75,6 +76,8 @@
 #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>
@@ -124,8 +127,8 @@
 #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
@@ -370,9 +373,6 @@ grace_alarm_handler(int sig)
 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)
@@ -381,12 +381,7 @@ generate_ephemeral_server_key(void)
             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();
 }
 
@@ -408,7 +403,7 @@ sshd_exchange_identification(int sock_in, int sock_out)
         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. */
 
@@ -419,11 +414,13 @@ sshd_exchange_identification(int sock_in, int sock_out)
         } 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. */
@@ -585,15 +582,14 @@ demote_sensitive_data(void)
 static void
 privsep_preauth_child(void)
 {
-        u_int32_t rnd[256];
+        u_int32_t rnd[256];
         gid_t gidset[1];
-        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. */
@@ -666,6 +662,8 @@ privsep_preauth(Authctxt *authctxt)
 static void
 privsep_postauth(Authctxt *authctxt)
 {
+        u_int32_t rnd[256];
+
 #ifdef DISABLE_FD_PASSING
         if (1) {
 #else
@@ -683,7 +681,7 @@ privsep_postauth(Authctxt *authctxt)
         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);
@@ -697,6 +695,10 @@ privsep_postauth(Authctxt *authctxt)
         /* 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);
 
@@ -796,7 +798,7 @@ drop_connection(int startups)
         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;
@@ -808,8 +810,9 @@ usage(void)
         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);
 }
@@ -957,8 +960,7 @@ server_listen(void)
                     ntop, sizeof(ntop), strport, sizeof(strport),
                     NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
                         error("getnameinfo failed: %.100s",
-                            (ret != EAI_SYSTEM) ? gai_strerror(ret) :
-                            strerror(errno));
+                            ssh_gai_strerror(ret));
                         continue;
                 }
                 /* Create socket for listening. */
@@ -981,6 +983,16 @@ server_listen(void)
                     &on, sizeof(on)) == -1)
                         error("setsockopt SO_REUSEADDR: %s", strerror(errno));
 
+#ifdef IPV6_V6ONLY
+                /* Only communicate in IPv6 over AF_INET6 sockets. */
+                if (ai->ai_family == AF_INET6) {
+                        if (setsockopt(listen_sock, IPPROTO_IPV6, IPV6_V6ONLY,
+                            &on, sizeof(on)) == -1)
+                                error("setsockopt IPV6_V6ONLY: %s",
+                                    strerror(errno));
+                }
+#endif
+
                 debug("Bind to port %s on %s.", strport, ntop);
 
                 /* Bind the socket to the desired port. */
@@ -1088,7 +1100,8 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
                         *newsock = accept(listen_socks[i],
                             (struct sockaddr *)&from, &fromlen);
                         if (*newsock < 0) {
-                                if (errno != EINTR && errno != EWOULDBLOCK)
+                                if (errno != EINTR && errno != EAGAIN &&
+                                    errno != EWOULDBLOCK)
                                         error("accept: %.100s", strerror(errno));
                                 continue;
                         }
@@ -1235,9 +1248,12 @@ main(int ac, char **av)
         int opt, i, on = 1;
         int sock_in = -1, sock_out = -1, newsock = -1;
         const char *remote_ip;
+        char *test_user = NULL, *test_host = NULL, *test_addr = NULL;
         int remote_port;
-        char *line;
+        char *line, *p, *cp;
         int config_s[2] = { -1 , -1 };
+        u_int64_t ibytes, obytes;
+        mode_t new_umask;
         Key *key;
         Authctxt *authctxt;
 
@@ -1271,7 +1287,7 @@ main(int ac, char **av)
         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;
@@ -1349,6 +1365,25 @@ main(int ac, char **av)
                 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 = (u_int)strtonum(optarg, 0, MAXHOSTNAMELEN+1, NULL);
                         if (utmp_len > MAXHOSTNAMELEN) {
@@ -1371,7 +1406,7 @@ main(int ac, char **av)
         }
         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);
@@ -1410,6 +1445,21 @@ main(int ac, char **av)
         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)
@@ -1541,6 +1591,13 @@ main(int ac, char **av)
                             "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);
@@ -1565,6 +1622,10 @@ main(int ac, char **av)
                 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;
@@ -1607,10 +1668,6 @@ main(int ac, char **av)
         /* Get a connection, either from inetd or a listening TCP socket */
         if (inetd_flag) {
                 server_accept_inetd(&sock_in, &sock_out);
-
-                if ((options.protocol & SSH_PROTO_1) &&
-                    sensitive_data.server_key == NULL)
-                        generate_ephemeral_server_key();
         } else {
                 server_listen();
 
@@ -1747,6 +1804,8 @@ main(int ac, char **av)
         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;
@@ -1834,6 +1893,10 @@ main(int ac, char **av)
 
         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 */
@@ -1886,6 +1949,20 @@ main(int ac, char **av)
         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.
@@ -1897,11 +1974,18 @@ main(int ac, char **av)
                         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)
@@ -1981,7 +2065,6 @@ do_ssh1_kex(void)
         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
@@ -1992,12 +2075,7 @@ do_ssh1_kex(void)
          * 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