X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/36a5b38eb813fdd1d8da0731b33aa967a066d8b8..5f4fdfae1aad347ce0a5e84495b7db5f38b3798b:/sshd.c

diff --git a/sshd.c b/sshd.c
index f3169078..03a9ce12 100644
--- a/sshd.c
+++ b/sshd.c
@@ -11,15 +11,7 @@
  */
 
 #include "includes.h"
-RCSID("$Id$");
-
-#ifdef HAVE_POLL_H
-# include <poll.h>
-#else /* HAVE_POLL_H */
-# ifdef HAVE_SYS_POLL_H
-#  include <sys/poll.h>
-# endif /* HAVE_SYS_POLL_H */
-#endif /* HAVE_POLL_H */
+RCSID("$OpenBSD: sshd.c,v 1.79 2000/01/18 13:45:05 markus Exp $");
 
 #include "xmalloc.h"
 #include "rsa.h"
@@ -53,6 +45,16 @@ ServerOptions options;
 /* Name of the server configuration file. */
 char *config_file_name = SERVER_CONFIG_FILE;
 
+/* 
+ * Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
+ * Default value is AF_UNSPEC means both IPv4 and IPv6.
+ */
+#ifdef IPV4_DEFAULT
+int IPv4or6 = AF_INET;
+#else
+int IPv4or6 = AF_UNSPEC;
+#endif
+
 /*
  * Debug mode flag.  This can be set on the command line.  If debug
  * mode is enabled, extra debugging output will be sent to the system
@@ -74,10 +76,12 @@ char *av0;
 char **saved_argv;
 
 /*
- * This is set to the socket that the server is listening; this is used in
- * the SIGHUP signal handler.
+ * The sockets that the server is listening; this is used in the SIGHUP
+ * signal handler.
  */
-int listen_sock;
+#define	MAX_LISTEN_SOCKS	16
+int listen_socks[MAX_LISTEN_SOCKS];
+int num_listen_socks = 0;
 
 /*
  * the client's version string, passed by sshd2 in compat mode. if != NULL,
@@ -127,8 +131,8 @@ int received_sighup = 0;
 RSA *public_key;
 
 /* Prototypes for various functions defined later in this file. */
-void do_connection();
-void do_authentication(char *user);
+void do_ssh_kex();
+void do_authentication();
 void do_authloop(struct passwd * pw);
 void do_fake_authloop(char *user);
 void do_authenticated(struct passwd * pw);
@@ -143,165 +147,17 @@ void do_child(const char *command, struct passwd * pw, const char *term,
 	      const char *display, const char *auth_proto,
 	      const char *auth_data, const char *ttyname);
 
-#ifdef HAVE_LIBPAM
-static int pamconv(int num_msg, const struct pam_message **msg,
-	  struct pam_response **resp, void *appdata_ptr);
-int do_pam_auth(const char *user, const char *password);
-void do_pam_account(char *username, char *remote_user);
-void do_pam_session(char *username, char *ttyname);
-void pam_cleanup_proc(void *context);
-
-static struct pam_conv conv = {
-	pamconv,
-	NULL
-};
-struct pam_handle_t *pamh = NULL;
-const char *pampasswd = NULL;
-char *pamconv_msg = NULL;
-
-static int pamconv(int num_msg, const struct pam_message **msg,
-	struct pam_response **resp, void *appdata_ptr)
-{
-	struct pam_response *reply;
-	int count;
-	size_t msg_len;
-	char *p;
-
-	/* PAM will free this later */
-	reply = malloc(num_msg * sizeof(*reply));
-	if (reply == NULL)
-		return PAM_CONV_ERR; 
-
-	for(count = 0; count < num_msg; count++) {
-		switch (msg[count]->msg_style) {
-			case PAM_PROMPT_ECHO_OFF:
-				if (pampasswd == NULL) {
-					free(reply);
-					return PAM_CONV_ERR;
-				}
-				reply[count].resp_retcode = PAM_SUCCESS;
-				reply[count].resp = xstrdup(pampasswd);
-				break;
-
-			case PAM_TEXT_INFO:
-				reply[count].resp_retcode = PAM_SUCCESS;
-				reply[count].resp = xstrdup("");
-
-				if (msg[count]->msg == NULL)
-					break;
-
-				debug("Adding PAM message: %s", msg[count]->msg);
-
-				msg_len = strlen(msg[count]->msg);
-				if (pamconv_msg) {
-					size_t n = strlen(pamconv_msg);
-					pamconv_msg = xrealloc(pamconv_msg, n + msg_len + 2);
-					p = pamconv_msg + n;
-				} else {
-					pamconv_msg = p = xmalloc(msg_len + 2);
-				}
-				memcpy(p, msg[count]->msg, msg_len);
-				p[msg_len] = '\n';
-				p[msg_len + 1] = '\0';
-				break;
-
-			case PAM_PROMPT_ECHO_ON:
-			case PAM_ERROR_MSG:
-			default:
-				free(reply);
-				return PAM_CONV_ERR;
-		}
-	}
-
-	*resp = reply;
-
-	return PAM_SUCCESS;
-}
-
-void pam_cleanup_proc(void *context)
-{
-	int pam_retval;
-
-	if (pamh != NULL)
-	{
-		pam_retval = pam_close_session((pam_handle_t *)pamh, 0);
-		if (pam_retval != PAM_SUCCESS) {
-			log("Cannot close PAM session: %.200s", 
-			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
-		}
-
-		pam_retval = pam_end((pam_handle_t *)pamh, pam_retval);
-		if (pam_retval != PAM_SUCCESS) {
-			log("Cannot release PAM authentication: %.200s", 
-			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
-		}
-	}
-}
-
-int do_pam_auth(const char *user, const char *password)
-{
-	int pam_retval;
-	
-	if ((options.permit_empty_passwd == 0) && (password[0] == '\0')
-		return 0;
-
-	pampasswd = password;
-	
-	pam_retval = pam_authenticate((pam_handle_t *)pamh, 0);
-	if (pam_retval == PAM_SUCCESS) {
-		debug("PAM Password authentication accepted for user \"%.100s\"", user);
-		return 1;
-	} else {
-		debug("PAM Password authentication for \"%.100s\" failed: %s", 
-			user, PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
-		return 0;
-	}
-}
-
-void do_pam_account(char *username, char *remote_user)
-{
-	int pam_retval;
-
-	debug("PAM setting rhost to \"%.200s\"", get_canonical_hostname());
-	pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RHOST, 
-		get_canonical_hostname());
-	if (pam_retval != PAM_SUCCESS) {
-		log("PAM set rhost failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
-		do_fake_authloop(username);
-	}
-
-	if (remote_user != NULL) {
-		debug("PAM setting ruser to \"%.200s\"", remote_user);
-		pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RUSER, remote_user);
-		if (pam_retval != PAM_SUCCESS) {
-			log("PAM set ruser failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
-			do_fake_authloop(username);
-		}
-	}
-
-	pam_retval = pam_acct_mgmt((pam_handle_t *)pamh, 0);
-	if (pam_retval != PAM_SUCCESS) {
-		log("PAM rejected by account configuration: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
-		do_fake_authloop(username);
-	}
-}
-
-void do_pam_session(char *username, char *ttyname)
+/*
+ * Close all listening sockets
+ */
+void
+close_listen_socks(void)
 {
-	int pam_retval;
-
-	if (ttyname != NULL) {
-		debug("PAM setting tty to \"%.200s\"", ttyname);
-		pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_TTY, ttyname);
-		if (pam_retval != PAM_SUCCESS)
-			fatal("PAM set tty failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
-	}
-
-	pam_retval = pam_open_session((pam_handle_t *)pamh, 0);
-	if (pam_retval != PAM_SUCCESS)
-		fatal("PAM session setup failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
+	int i;
+	for (i = 0; i < num_listen_socks; i++)
+		close(listen_socks[i]);
+	num_listen_socks = -1;
 }
-#endif /* HAVE_LIBPAM */
 
 /*
  * Signal handler for SIGHUP.  Sshd execs itself when it receives SIGHUP;
@@ -323,7 +179,7 @@ void
 sighup_restart()
 {
 	log("Received SIGHUP; restarting.");
-	close(listen_sock);
+	close_listen_socks();
 	execv(saved_argv[0], saved_argv);
 	log("RESTART FAILED: av0='%s', error: %s.", av0, strerror(errno));
 	exit(1);
@@ -338,7 +194,7 @@ void
 sigterm_handler(int sig)
 {
 	log("Received signal %d; terminating.", sig);
-	close(listen_sock);
+	close_listen_socks();
 	exit(255);
 }
 
@@ -445,11 +301,12 @@ main(int ac, char **av)
 {
 	extern char *optarg;
 	extern int optind;
-	int opt, aux, sock_in, sock_out, newsock, i, pid, on = 1;
+	int opt, sock_in = 0, sock_out = 0, newsock, i, fdsetsz, pid, on = 1;
+	socklen_t fromlen;
 	int remote_major, remote_minor;
 	int silentrsa = 0;
-	struct pollfd fds;
-	struct sockaddr_in sin;
+	fd_set *fdset;
+	struct sockaddr_storage from;
 	char buf[100];			/* Must not be larger than remote_version. */
 	char remote_version[100];	/* Must be at least as big as buf. */
 	const char *remote_ip;
@@ -457,6 +314,9 @@ main(int ac, char **av)
 	char *comment;
 	FILE *f;
 	struct linger linger;
+	struct addrinfo *ai;
+	char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+	int listen_sock, maxfd;
 
 	/* Save argv[0]. */
 	saved_argv = av;
@@ -469,8 +329,14 @@ main(int ac, char **av)
 	initialize_server_options(&options);
 
 	/* Parse command-line arguments. */
-	while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:diqQ")) != EOF) {
+	while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:diqQ46")) != EOF) {
 		switch (opt) {
+		case '4':
+			IPv4or6 = AF_INET;
+			break;
+		case '6':
+			IPv4or6 = AF_INET6;
+			break;
 		case 'f':
 			config_file_name = optarg;
 			break;
@@ -491,7 +357,10 @@ main(int ac, char **av)
 			options.server_key_bits = atoi(optarg);
 			break;
 		case 'p':
-			options.port = atoi(optarg);
+			options.ports_from_cmdline = 1;
+			if (options.num_ports >= MAX_PORTS)
+				fatal("too many ports.\n");
+			options.ports[options.num_ports++] = atoi(optarg);
 			break;
 		case 'g':
 			options.login_grace_time = atoi(optarg);
@@ -510,6 +379,9 @@ main(int ac, char **av)
 		case '?':
 		default:
 			fprintf(stderr, "sshd version %s\n", SSH_VERSION);
+#ifdef RSAREF
+			fprintf(stderr, "Compiled with RSAref.\n");
+#endif
 			fprintf(stderr, "Usage: %s [options]\n", av0);
 			fprintf(stderr, "Options:\n");
 			fprintf(stderr, "  -f file    Configuration file (default %s)\n", SERVER_CONFIG_FILE);
@@ -521,11 +393,22 @@ main(int ac, char **av)
 			fprintf(stderr, "  -g seconds Grace period for authentication (default: 300)\n");
 			fprintf(stderr, "  -b bits    Size of server RSA key (default: 768 bits)\n");
 			fprintf(stderr, "  -h file    File from which to read host key (default: %s)\n",
-				HOST_KEY_FILE);
+			    HOST_KEY_FILE);
+			fprintf(stderr, "  -4         Use IPv4 only\n");
+			fprintf(stderr, "  -6         Use IPv6 only\n");
 			exit(1);
 		}
 	}
 
+	/*
+	 * Force logging to stderr until we have loaded the private host
+	 * key (unless started from inetd)
+	 */
+	log_init(av0,
+	    options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
+	    options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility,
+	    !inetd_flag);
+
 	/* check if RSA support exists */
 	if (rsa_alive() == 0) {
 		if (silentrsa == 0)
@@ -545,18 +428,11 @@ main(int ac, char **av)
 		fprintf(stderr, "Bad server key size.\n");
 		exit(1);
 	}
-	if (options.port < 1 || options.port > 65535) {
-		fprintf(stderr, "Bad port number.\n");
-		exit(1);
-	}
 	/* Check that there are no remaining arguments. */
 	if (optind < ac) {
 		fprintf(stderr, "Extra argument %s.\n", av[optind]);
 		exit(1);
 	}
-	/* Force logging to stderr while loading the private host key
-	   unless started from inetd */
-	log_init(av0, options.log_level, options.log_facility, !inetd_flag);
 
 	debug("sshd version %.100s", SSH_VERSION);
 
@@ -645,32 +521,66 @@ main(int ac, char **av)
 		arc4random_stir();
 		log("RSA key generation complete.");
 	} else {
-		/* Create socket for listening. */
-		listen_sock = socket(AF_INET, SOCK_STREAM, 0);
-		if (listen_sock < 0)
-			fatal("socket: %.100s", strerror(errno));
-
-		/* Set socket options.  We try to make the port reusable
-		   and have it close as fast as possible without waiting
-		   in unnecessary wait states on close. */
-		setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, (void *) &on,
-			   sizeof(on));
-		linger.l_onoff = 1;
-		linger.l_linger = 5;
-		setsockopt(listen_sock, SOL_SOCKET, SO_LINGER, (void *) &linger,
-			   sizeof(linger));
-
-		memset(&sin, 0, sizeof(sin));
-		sin.sin_family = AF_INET;
-		sin.sin_addr = options.listen_addr;
-		sin.sin_port = htons(options.port);
-
-		if (bind(listen_sock, (struct sockaddr *) & sin, sizeof(sin)) < 0) {
-			error("bind: %.100s", strerror(errno));
-			shutdown(listen_sock, SHUT_RDWR);
-			close(listen_sock);
-			fatal("Bind to port %d failed.", options.port);
+		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 (getnameinfo(ai->ai_addr, ai->ai_addrlen,
+			    ntop, sizeof(ntop), strport, sizeof(strport),
+			    NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
+				error("getnameinfo failed");
+				continue;
+			}
+			/* Create socket for listening. */
+			listen_sock = socket(ai->ai_family, SOCK_STREAM, 0);
+			if (listen_sock < 0) {
+				/* kernel may not support ipv6 */
+				verbose("socket: %.100s", strerror(errno));
+				continue;
+			}
+			if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) {
+				error("listen_sock O_NONBLOCK: %s", strerror(errno));
+				close(listen_sock);
+				continue;
+			}
+			/*
+			 * Set socket options.  We try to make the port
+			 * reusable and have it close as fast as possible
+			 * without waiting in unnecessary wait states on
+			 * close.
+			 */
+			setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
+			    (void *) &on, sizeof(on));
+			linger.l_onoff = 1;
+			linger.l_linger = 5;
+			setsockopt(listen_sock, SOL_SOCKET, SO_LINGER,
+			    (void *) &linger, sizeof(linger));
+
+			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. */
+			log("Server listening on %s port %s.", ntop, strport);
+			if (listen(listen_sock, 5) < 0)
+				fatal("listen: %.100s", strerror(errno));
+
 		}
+		freeaddrinfo(options.listen_addrs);
+
+		if (!num_listen_socks)
+			fatal("Cannot bind any address.");
+
 		if (!debug_flag) {
 			/*
 			 * Record our pid in /etc/sshd_pid to make it easier
@@ -686,10 +596,6 @@ main(int ac, char **av)
 			}
 		}
 
-		log("Server listening on port %d.", options.port);
-		if (listen(listen_sock, 5) < 0)
-			fatal("listen: %.100s", strerror(errno));
-
 		public_key = RSA_new();
 		sensitive_data.private_key = RSA_new();
 
@@ -711,6 +617,14 @@ main(int ac, char **av)
 		/* Arrange SIGCHLD to be caught. */
 		signal(SIGCHLD, main_sigchld_handler);
 
+		/* setup fd set for listen */
+		maxfd = 0;
+		for (i = 0; i < num_listen_socks; i++)
+			if (listen_socks[i] > maxfd)
+				maxfd = listen_socks[i];
+		fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);         
+		fdset = (fd_set *)xmalloc(fdsetsz);                                  
+
 		/*
 		 * Stay listening for connections until the system crashes or
 		 * the daemon is killed with a signal.
@@ -718,26 +632,28 @@ main(int ac, char **av)
 		for (;;) {
 			if (received_sighup)
 				sighup_restart();
-			/* Wait in poll until there is a connection. */
-			memset(&fds, 0, sizeof(fds));
-			fds.fd = listen_sock;
-			fds.events = POLLIN;
-			if (poll(&fds, 1, -1) == -1) {
-				if (errno == EINTR)
-					continue;
-				fatal("poll: %.100s", strerror(errno));
-				/*NOTREACHED*/
-			}
-			if (fds.revents == 0)
+			/* Wait in select until there is a connection. */
+			memset(fdset, 0, fdsetsz);
+			for (i = 0; i < num_listen_socks; i++)
+				FD_SET(listen_socks[i], fdset);
+			if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) {
+				if (errno != EINTR)
+					error("select: %.100s", strerror(errno));
 				continue;
-			aux = sizeof(sin);
-			newsock = accept(listen_sock, (struct sockaddr *) & sin, &aux);
-			if (received_sighup)
-				sighup_restart();
-			if (newsock < 0) {
-				if (errno == EINTR)
+			}
+			for (i = 0; i < num_listen_socks; i++) {
+				if (!FD_ISSET(listen_socks[i], fdset))
 					continue;
-				error("accept: %.100s", strerror(errno));
+			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 (fcntl(newsock, F_SETFL, 0) < 0) {
+				error("newsock del O_NONBLOCK: %s", strerror(errno));
 				continue;
 			}
 			/*
@@ -751,7 +667,7 @@ main(int ac, char **av)
 				 * connection without forking.
 				 */
 				debug("Server will not fork when running in debugging mode.");
-				close(listen_sock);
+				close_listen_socks();
 				sock_in = newsock;
 				sock_out = newsock;
 				pid = getpid();
@@ -768,7 +684,7 @@ main(int ac, char **av)
 					 * accepted socket.  Reinitialize logging (since our pid has
 					 * changed).  We break out of the loop to handle the connection.
 					 */
-					close(listen_sock);
+					close_listen_socks();
 					sock_in = newsock;
 					sock_out = newsock;
 					log_init(av0, options.log_level, options.log_facility, log_stderr);
@@ -789,6 +705,10 @@ main(int ac, char **av)
 
 			/* Close the new socket (the child is now taking care of it). */
 			close(newsock);
+			} /* for (i = 0; i < num_listen_socks; i++) */
+			/* child process check (or debug mode) */
+			if (num_listen_socks < 0)
+				break;
 		}
 	}
 
@@ -827,6 +747,7 @@ main(int ac, char **av)
 
 	/* Check whether logins are denied from this host. */
 #ifdef LIBWRAP
+	/* XXX LIBWRAP noes not know about IPv6 */
 	{
 		struct request_info req;
 
@@ -838,12 +759,11 @@ main(int ac, char **av)
 			close(sock_out);
 			refuse(&req);
 		}
-		verbose("Connection from %.500s port %d", eval_client(&req), remote_port);
+/*XXX IPv6 verbose("Connection from %.500s port %d", eval_client(&req), remote_port); */
 	}
-#else
+#endif /* LIBWRAP */
 	/* Log the connection. */
 	verbose("Connection from %.500s port %d", remote_ip, remote_port);
-#endif /* LIBWRAP */
 
 	/*
 	 * We don\'t want to listen forever unless the other side
@@ -865,12 +785,12 @@ main(int ac, char **av)
 		snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
 			 PROTOCOL_MAJOR, PROTOCOL_MINOR, SSH_VERSION);
 		if (atomicio(write, sock_out, buf, strlen(buf)) != strlen(buf))
-			fatal("Could not write ident string to %s.", get_remote_ipaddr());
+			fatal("Could not write ident string to %s.", remote_ip);
 
 		/* Read other side\'s version identification. */
 		for (i = 0; i < sizeof(buf) - 1; i++) {
 			if (read(sock_in, &buf[i], 1) != 1)
-				fatal("Did not receive ident string from %s.", get_remote_ipaddr());
+				fatal("Did not receive ident string from %s.", remote_ip);
 			if (buf[i] == '\r') {
 				buf[i] = '\n';
 				buf[i + 1] = 0;
@@ -897,7 +817,7 @@ main(int ac, char **av)
 		close(sock_in);
 		close(sock_out);
 		fatal("Bad protocol version identification '%.100s' from %s",
-		      buf, get_remote_ipaddr());
+		      buf, remote_ip);
 	}
 	debug("Client protocol version %d.%d; client software version %.100s",
 	      remote_major, remote_minor, remote_version);
@@ -908,19 +828,15 @@ main(int ac, char **av)
 		close(sock_in);
 		close(sock_out);
 		fatal("Protocol major versions differ for %s: %d vs. %d",
-		      get_remote_ipaddr(),
-		      PROTOCOL_MAJOR, remote_major);
+		      remote_ip, PROTOCOL_MAJOR, remote_major);
 	}
 	/* Check that the client has sufficiently high software version. */
 	if (remote_major == 1 && remote_minor < 3)
 		packet_disconnect("Your ssh version is too old and is no longer supported.  Please install a newer version.");
 
 	if (remote_major == 1 && remote_minor == 3) {
+		/* note that this disables agent-forwarding */
 		enable_compat13();
-		if (strcmp(remote_version, "OpenSSH-1.1") != 0) {
-			debug("Agent forwarding disabled, remote version is not compatible.");
-			no_agent_forwarding_flag = 1;
-		}
 	}
 	/*
 	 * Check that the connection comes from a privileged port.  Rhosts-
@@ -934,10 +850,21 @@ main(int ac, char **av)
 		options.rhosts_authentication = 0;
 		options.rhosts_rsa_authentication = 0;
 	}
+#ifdef KRB4
+	if (!packet_connection_is_ipv4() &&
+	    options.kerberos_authentication) {
+		debug("Kerberos Authentication disabled, only available for IPv4.");
+		options.kerberos_authentication = 0;
+	}
+#endif /* KRB4 */
+
 	packet_set_nonblocking();
 
-	/* Handle the connection. */
-	do_connection();
+	/* perform the key exchange */
+	do_ssh_kex();
+
+	/* authenticate user and start session */
+	do_authentication();
 
 #ifdef KRB4
 	/* Cleanup user's ticket cache file. */
@@ -952,42 +879,26 @@ main(int ac, char **av)
 	/* The connection has been terminated. */
 	verbose("Closing connection to %.100s", remote_ip);
 
-#ifdef HAVE_LIBPAM
-	{
-		int retval;
-
-		if (pamh != NULL) {
-			debug("Closing PAM session.");
-			retval = pam_close_session((pam_handle_t *)pamh, 0);
-
-			debug("Terminating PAM library.");
-			if (pam_end((pam_handle_t *)pamh, retval) != PAM_SUCCESS)
-				log("Cannot release PAM authentication.");
-
-			fatal_remove_cleanup(&pam_cleanup_proc, NULL);
-		}
-	}
-#endif /* HAVE_LIBPAM */
+#ifdef USE_PAM
+	finish_pam();
+#endif /* USE_PAM */
 
 	packet_close();
 	exit(0);
 }
 
 /*
- * Process an incoming connection.  Protocol version identifiers have already
- * been exchanged.  This sends server key and performs the key exchange.
- * Server and host keys will no longer be needed after this functions.
+ * SSH1 key exchange
  */
 void
-do_connection()
+do_ssh_kex()
 {
 	int i, len;
+	int plen, slen;
 	BIGNUM *session_key_int;
 	unsigned char session_key[SSH_SESSION_KEY_LENGTH];
-	unsigned char check_bytes[8];
-	char *user;
+	unsigned char cookie[8];
 	unsigned int cipher_type, auth_mask, protocol_flags;
-	int plen, slen, ulen;
 	u_int32_t rand = 0;
 
 	/*
@@ -1002,7 +913,7 @@ do_connection()
 	for (i = 0; i < 8; i++) {
 		if (i % 4 == 0)
 			rand = arc4random();
-		check_bytes[i] = rand & 0xff;
+		cookie[i] = rand & 0xff;
 		rand >>= 8;
 	}
 
@@ -1013,7 +924,7 @@ do_connection()
 	 */
 	packet_start(SSH_SMSG_PUBLIC_KEY);
 	for (i = 0; i < 8; i++)
-		packet_put_char(check_bytes[i]);
+		packet_put_char(cookie[i]);
 
 	/* Store our public server RSA key. */
 	packet_put_int(BN_num_bits(public_key->n));
@@ -1076,7 +987,7 @@ do_connection()
 	/* Get check bytes from the packet.  These must match those we
 	   sent earlier with the public key packet. */
 	for (i = 0; i < 8; i++)
-		if (check_bytes[i] != packet_get_char())
+		if (cookie[i] != packet_get_char())
 			packet_disconnect("IP Spoofing check bytes do not match.");
 
 	debug("Encryption type: %.200s", cipher_name(cipher_type));
@@ -1124,10 +1035,15 @@ do_connection()
 				    sensitive_data.private_key);
 	}
 
-	compute_session_id(session_id, check_bytes,
+	compute_session_id(session_id, cookie,
 			   sensitive_data.host_key->n,
 			   sensitive_data.private_key->n);
 
+	/* Destroy the private and public keys.  They will no longer be needed. */
+	RSA_free(public_key);
+	RSA_free(sensitive_data.private_key);
+	RSA_free(sensitive_data.host_key);
+
 	/*
 	 * Extract session key from the decrypted integer.  The key is in the
 	 * least significant 256 bits of the integer; the first byte of the
@@ -1142,13 +1058,13 @@ do_connection()
 	memset(session_key, 0, sizeof(session_key));
 	BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len);
 
+	/* Destroy the decrypted integer.  It is no longer needed. */
+	BN_clear_free(session_key_int);
+
 	/* Xor the first 16 bytes of the session key with the session id. */
 	for (i = 0; i < 16; i++)
 		session_key[i] ^= session_id[i];
 
-	/* Destroy the decrypted integer.  It is no longer needed. */
-	BN_clear_free(session_key_int);
-
 	/* Set the session key.  From this on all communications will be encrypted. */
 	packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
 
@@ -1161,24 +1077,9 @@ do_connection()
 	packet_start(SSH_SMSG_SUCCESS);
 	packet_send();
 	packet_write_wait();
-
-	/* Get the name of the user that we wish to log in as. */
-	packet_read_expect(&plen, SSH_CMSG_USER);
-
-	/* Get the user name. */
-	user = packet_get_string(&ulen);
-	packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER);
-
-	/* Destroy the private and public keys.  They will no longer be needed. */
-	RSA_free(public_key);
-	RSA_free(sensitive_data.private_key);
-	RSA_free(sensitive_data.host_key);
-
-	setproctitle("%s", user);
-	/* Do the authentication. */
-	do_authentication(user);
 }
 
+
 /*
  * Check if the user is allowed to log in via ssh. If user is listed in
  * DenyUsers or user's primary group is listed in DenyGroups, false will
@@ -1254,13 +1155,23 @@ allowed_user(struct passwd * pw)
 
 /*
  * Performs authentication of an incoming connection.  Session key has already
- * been exchanged and encryption is enabled.  User is the user name to log
- * in as (received from the client).
+ * been exchanged and encryption is enabled.
  */
 void
-do_authentication(char *user)
+do_authentication()
 {
 	struct passwd *pw, pwcopy;
+	int plen, ulen;
+	char *user;
+
+	/* Get the name of the user that we wish to log in as. */
+	packet_read_expect(&plen, SSH_CMSG_USER);
+
+	/* Get the user name. */
+	user = packet_get_string(&ulen);
+	packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER);
+
+	setproctitle("%s", user);
 
 #ifdef AFS
 	/* If machine has AFS, set process authentication group. */
@@ -1285,18 +1196,8 @@ do_authentication(char *user)
 	pwcopy.pw_shell = xstrdup(pw->pw_shell);
 	pw = &pwcopy;
 
-#ifdef HAVE_LIBPAM
-	{
-		int pam_retval;
-
-		debug("Starting up PAM with username \"%.200s\"", pw->pw_name);
-
-		pam_retval = pam_start("sshd", pw->pw_name, &conv, (pam_handle_t**)&pamh);
-		if (pam_retval != PAM_SUCCESS)
-			fatal("PAM initialisation failed: %.200s", PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
-
-		fatal_add_cleanup(&pam_cleanup_proc, NULL);
-	}
+#ifdef USE_PAM
+	start_pam(pw);
 #endif
 
 	/*
@@ -1313,11 +1214,11 @@ do_authentication(char *user)
 #ifdef KRB4
 	    (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
 #endif /* KRB4 */
-#ifdef HAVE_LIBPAM
-	    do_pam_auth(pw->pw_name, "")) {
-#else /* HAVE_LIBPAM */
+#ifdef USE_PAM
+	    auth_pam_password(pw, "")) {
+#else /* USE_PAM */
 	    auth_password(pw, "")) {
-#endif /* HAVE_LIBPAM */
+#endif /* USE_PAM */
 		/* Authentication with empty password succeeded. */
 		log("Login for user %s from %.100s, accepted without authentication.",
 		    pw->pw_name, get_remote_ipaddr());
@@ -1457,9 +1358,6 @@ do_authloop(struct passwd * pw)
 			authenticated = auth_rhosts(pw, client_user);
 
 			snprintf(user, sizeof user, " ruser %s", client_user);
-#ifndef HAVE_LIBPAM
-			xfree(client_user);
-#endif /* HAVE_LIBPAM */
 			break;
 
 		case SSH_CMSG_AUTH_RHOSTS_RSA:
@@ -1492,9 +1390,6 @@ do_authloop(struct passwd * pw)
 			BN_clear_free(client_host_key_n);
 
 			snprintf(user, sizeof user, " ruser %s", client_user);
-#ifndef HAVE_LIBPAM
-			xfree(client_user);
-#endif /* HAVE_LIBPAM */
 			break;
 
 		case SSH_CMSG_AUTH_RSA:
@@ -1523,13 +1418,13 @@ do_authloop(struct passwd * pw)
 			password = packet_get_string(&dlen);
 			packet_integrity_check(plen, 4 + dlen, type);
 
-#ifdef HAVE_LIBPAM
+#ifdef USE_PAM
 			/* Do PAM auth with password */
-			authenticated = do_pam_auth(pw->pw_name, password);
-#else /* HAVE_LIBPAM */
+			authenticated = auth_pam_password(pw, password);
+#else /* USE_PAM */
 			/* Try authentication with the password. */
 			authenticated = auth_password(pw, password);
-#endif /* HAVE_LIBPAM */
+#endif /* USE_PAM */
 			memset(password, 0, strlen(password));
 			xfree(password);
 			break;
@@ -1595,29 +1490,24 @@ do_authloop(struct passwd * pw)
 			get_remote_port(),
 			user);
 
-#ifndef HAVE_LIBPAM
-		if (authenticated)
-			return;
-
-		if (attempt > AUTH_FAIL_MAX)
-			packet_disconnect(AUTH_FAIL_MSG, pw->pw_name);
-#else /* HAVE_LIBPAM */
 		if (authenticated) {
-			do_pam_account(pw->pw_name, client_user);
-
-			if (client_user != NULL)
-				xfree(client_user);
+#ifdef USE_PAM
+			if (!do_pam_account(pw->pw_name, client_user))
+			{
+				if (client_user != NULL)
+					xfree(client_user);
 
+				do_fake_authloop(pw->pw_name);
+			}
+#endif /* USE_PAM */
 			return;
 		}
 
-		if (attempt > AUTH_FAIL_MAX) {
-			if (client_user != NULL)
-				xfree(client_user);
+		if (client_user != NULL)
+			xfree(client_user);
 
+		if (attempt > AUTH_FAIL_MAX)
 			packet_disconnect(AUTH_FAIL_MSG, pw->pw_name);
-		}
-#endif /* HAVE_LIBPAM */
 
 		/* Send a message indicating that the authentication attempt failed. */
 		packet_start(SSH_SMSG_FAILURE);
@@ -1652,8 +1542,10 @@ do_fake_authloop(char *user)
 	for (attempt = 1;; attempt++) {
 		/* Read a packet.  This will not return if the client disconnects. */
 		int plen;
+#ifndef SKEY
+		(void)packet_read(&plen);
+#else /* SKEY */
 		int type = packet_read(&plen);
-#ifdef SKEY
 		int dlen;
 		char *password, *skeyinfo;
 		/* Try to send a fake s/key challenge. */
@@ -1823,10 +1715,10 @@ do_authenticated(struct passwd * pw)
 			/* Indicate that we now have a pty. */
 			have_pty = 1;
 
-#ifdef HAVE_LIBPAM
+#ifdef USE_PAM
 			/* do the pam_open_session since we have the pty */
-			do_pam_session(pw->pw_name,ttyname);
-#endif /* HAVE_LIBPAM */
+			do_pam_session(pw->pw_name, ttyname);
+#endif /* USE_PAM */
 
 			break;
 
@@ -1876,7 +1768,7 @@ do_authenticated(struct passwd * pw)
 #endif /* XAUTH_PATH */
 
 		case SSH_CMSG_AGENT_REQUEST_FORWARDING:
-			if (no_agent_forwarding_flag) {
+			if (no_agent_forwarding_flag || compat13) {
 				debug("Authentication agent forwarding not permitted for this authentication.");
 				goto fail;
 			}
@@ -1903,6 +1795,9 @@ do_authenticated(struct passwd * pw)
 			packet_set_interactive(have_pty || display != NULL,
 					       options.keepalives);
 
+#ifdef USE_PAM
+			do_pam_setcred();
+#endif /* USE_PAM */
 			if (forced_command != NULL)
 				goto do_forced_command;
 			debug("Forking shell.");
@@ -1918,6 +1813,9 @@ do_authenticated(struct passwd * pw)
 			packet_set_interactive(have_pty || display != NULL,
 					       options.keepalives);
 
+#ifdef USE_PAM
+			do_pam_setcred();
+#endif /* USE_PAM */
 			if (forced_command != NULL)
 				goto do_forced_command;
 			/* Get command from the packet. */
@@ -2126,8 +2024,8 @@ do_exec_pty(const char *command, int ptyfd, int ttyfd,
 	char line[256];
 	struct stat st;
 	int quiet_login;
-	struct sockaddr_in from;
-	int fromlen;
+	struct sockaddr_storage from;
+	socklen_t fromlen;
 	struct pty_cleanup_context cleanup_context;
 
 	/* Get remote host name. */
@@ -2188,17 +2086,16 @@ do_exec_pty(const char *command, int ptyfd, int ttyfd,
 		}
 		/* Record that there was a login on that terminal. */
 		record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname,
-			     &from);
+			     (struct sockaddr *)&from);
 
 		/* Check if .hushlogin exists. */
 		snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir);
 		quiet_login = stat(line, &st) >= 0;
 
-#ifdef HAVE_LIBPAM
-		/* output the results of the pamconv() */
-		if (!quiet_login && pamconv_msg != NULL)
-			fprintf(stderr, pamconv_msg);
-#endif
+#ifdef USE_PAM
+		if (!quiet_login)
+			print_pam_messages();
+#endif /* USE_PAM */
 
 		/*
 		 * If the user has logged in before, display the time of last
@@ -2363,6 +2260,39 @@ read_environment_file(char ***env, unsigned int *envsize,
 	fclose(f);
 }
 
+#ifdef USE_PAM
+/*
+ * Sets any environment variables which have been specified by PAM
+ */
+void do_pam_environment(char ***env, int *envsize)
+{
+	char *equals, var_name[512], var_val[512];
+	char **pam_env;
+	int i;
+
+	if ((pam_env = fetch_pam_environment()) == NULL)
+		return;
+	
+	for(i = 0; pam_env[i] != NULL; i++) {
+		if ((equals = strstr(pam_env[i], "=")) == NULL)
+			continue;
+			
+		if (strlen(pam_env[i]) < (sizeof(var_name) - 1))
+		{
+			memset(var_name, '\0', sizeof(var_name));
+			memset(var_val, '\0', sizeof(var_val));
+
+			strncpy(var_name, pam_env[i], equals - pam_env[i]);
+			strcpy(var_val, equals + 1);
+
+			debug("PAM environment: %s=%s", var_name, var_val);
+
+			child_set_env(env, envsize, var_name, var_val);
+		}
+	}
+}
+#endif /* USE_PAM */
+
 /*
  * Performs common processing for the child, such as setting up the
  * environment, closing extra file descriptors, setting the user and group
@@ -2382,7 +2312,7 @@ do_child(const char *command, struct passwd * pw, const char *term,
 	struct stat st;
 	char *argv[10];
 
-#ifndef HAVE_LIBPAM /* pam_nologin handles this */
+#ifndef USE_PAM /* pam_nologin handles this */
 	/* Check /etc/nologin. */
 	f = fopen("/etc/nologin", "r");
 	if (f) {
@@ -2393,13 +2323,11 @@ do_child(const char *command, struct passwd * pw, const char *term,
 		if (pw->pw_uid != 0)
 			exit(254);
 	}
-#endif /* HAVE_LIBPAM */
+#endif /* USE_PAM */
 
-#ifdef HAVE_SETLOGIN
 	/* Set login name in the kernel. */
 	if (setlogin(pw->pw_name) < 0)
 		error("setlogin failed: %s", strerror(errno));
-#endif /* HAVE_SETLOGIN */
 
 	/* Set uid, gid, and groups. */
 	/* Login(1) does this as well, and it needs uid 0 for the "-h"
@@ -2479,7 +2407,7 @@ do_child(const char *command, struct passwd * pw, const char *term,
 	}
 
 	snprintf(buf, sizeof buf, "%.50s %d %d",
-		 get_remote_ipaddr(), get_remote_port(), options.port);
+		 get_remote_ipaddr(), get_remote_port(), get_local_port());
 	child_set_env(&env, &envsize, "SSH_CLIENT", buf);
 
 	if (ttyname)
@@ -2498,26 +2426,10 @@ do_child(const char *command, struct passwd * pw, const char *term,
 	}
 #endif /* KRB4 */
 
-#ifdef HAVE_LIBPAM
+#ifdef USE_PAM
 	/* Pull in any environment variables that may have been set by PAM. */
-	{
-		char *equals, var_name[512], var_val[512];
-		char **pam_env = pam_getenvlist((pam_handle_t *)pamh);
-		int i;
-		for(i = 0; pam_env && pam_env[i]; i++) {
-			equals = strstr(pam_env[i], "=");
-			if ((strlen(pam_env[i]) < (sizeof(var_name) - 1)) && (equals != NULL))
-			{
-				debug("PAM environment: %s=%s", var_name, var_val);
-				memset(var_name, '\0', sizeof(var_name));
-				memset(var_val, '\0', sizeof(var_val));
-				strncpy(var_name, pam_env[i], equals - pam_env[i]);
-				strcpy(var_val, equals + 1);
-				child_set_env(&env, &envsize, var_name, var_val);
-			}
-		}
-	}
-#endif /* HAVE_LIBPAM */
+	do_pam_environment(&env, &envsize);
+#endif /* USE_PAM */
 
 	if (xauthfile)
 		child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
@@ -2562,7 +2474,6 @@ do_child(const char *command, struct passwd * pw, const char *term,
 	 * descriptors left by system functions.  They will be closed later.
 	 */
 	endpwent();
-	endhostent();
 
 	/*
 	 * Close any extra open file descriptors so that we don\'t have them