diff options
Diffstat (limited to 'crypto/openssh/sshd.c')
| -rw-r--r-- | crypto/openssh/sshd.c | 163 |
1 files changed, 123 insertions, 40 deletions
diff --git a/crypto/openssh/sshd.c b/crypto/openssh/sshd.c index 5832526..901615d 100644 --- a/crypto/openssh/sshd.c +++ b/crypto/openssh/sshd.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshd.c,v 1.348 2006/11/06 21:25:28 markus 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 @@ -55,6 +55,7 @@ __RCSID("$FreeBSD$"); # include <sys/time.h> #endif #include "openbsd-compat/sys-tree.h" +#include "openbsd-compat/sys-queue.h" #include <sys/wait.h> #include <errno.h> @@ -76,6 +77,8 @@ __RCSID("$FreeBSD$"); #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> @@ -130,8 +133,8 @@ __RCSID("$FreeBSD$"); #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 @@ -315,6 +318,7 @@ sighup_restart(void) logit("Received SIGHUP; restarting."); close_listen_socks(); close_startup_pipes(); + alarm(0); /* alarm timer persists across exec */ execv(saved_argv[0], saved_argv); logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], strerror(errno)); @@ -375,9 +379,6 @@ 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) @@ -386,12 +387,7 @@ 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(); } @@ -413,7 +409,7 @@ 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. */ @@ -424,11 +420,13 @@ 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. */ @@ -590,15 +588,14 @@ 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. */ @@ -671,6 +668,8 @@ privsep_preauth(Authctxt *authctxt) static void privsep_postauth(Authctxt *authctxt) { + u_int32_t rnd[256]; + #ifdef DISABLE_FD_PASSING if (1) { #else @@ -688,7 +687,7 @@ 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); @@ -702,6 +701,10 @@ 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); @@ -801,7 +804,7 @@ 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; @@ -813,8 +816,9 @@ 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); } @@ -962,8 +966,7 @@ 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. */ @@ -986,6 +989,16 @@ 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. */ @@ -1093,7 +1106,8 @@ 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; } @@ -1240,9 +1254,12 @@ 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; @@ -1276,7 +1293,7 @@ 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; @@ -1354,6 +1371,25 @@ 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) { @@ -1376,7 +1412,7 @@ 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); @@ -1415,6 +1451,21 @@ 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) @@ -1430,6 +1481,10 @@ main(int ac, char **av) /* 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); @@ -1539,6 +1594,13 @@ 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); @@ -1563,6 +1625,10 @@ 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; @@ -1605,10 +1671,6 @@ 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(); @@ -1768,6 +1830,8 @@ 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; @@ -1801,6 +1865,10 @@ 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 */ @@ -1853,6 +1921,20 @@ 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. @@ -1864,11 +1946,18 @@ 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) @@ -1948,7 +2037,6 @@ 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 @@ -1959,12 +2047,7 @@ 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 |
