split sshd.c -> auth.c session.c sshd.c plus cleanup and goto-removal

1 files changed, 101 insertions, 1624 deletions

diff --git a/usr.bin/ssh/sshd.c b/usr.bin/ssh/sshd.c
index 282444a12c9..a5dc749885c 100644
--- a/usr.bin/ssh/sshd.c
+++ b/usr.bin/ssh/sshd.c
@@ -11,21 +11,28 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.95 2000/03/28 20:31:29 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.96 2000/03/28 21:15:45 markus Exp $");
 
 #include "xmalloc.h"
 #include "rsa.h"
 #include "ssh.h"
 #include "pty.h"
 #include "packet.h"
-#include "buffer.h"
 #include "cipher.h"
 #include "mpaux.h"
 #include "servconf.h"
 #include "uidswap.h"
-#include "match.h"
-#include "channels.h"
 #include "compat.h"
+#include "buffer.h"
+
+#include <ssl/dh.h>
+#include <ssl/bn.h>
+#include <ssl/hmac.h>
+#include <ssl/dsa.h>
+#include <ssl/rsa.h>
+#include "key.h"
+
+#include "auth.h"
 
 #ifdef LIBWRAP
 #include <tcpd.h>
@@ -38,9 +45,6 @@ int deny_severity = LOG_WARNING;
 #define O_NOCTTY	0
 #endif
 
-/* Local Xauthority file. */
-static char *xauthfile = NULL;
-
 /* Server configuration options. */
 ServerOptions options;
 
@@ -86,21 +90,7 @@ int num_listen_socks = 0;
  * sshd will skip the version-number exchange
  */
 char *client_version_string = NULL;
-
-/* Flags set in auth-rsa from authorized_keys flags.  These are set in auth-rsa.c. */
-int no_port_forwarding_flag = 0;
-int no_agent_forwarding_flag = 0;
-int no_x11_forwarding_flag = 0;
-int no_pty_flag = 0;
-
-/* RSA authentication "command=" option. */
-char *forced_command = NULL;
-
-/* RSA authentication "environment=" options. */
-struct envstring *custom_environment = NULL;
-
-/* Session id for the current session. */
-unsigned char session_id[16];
+char *server_version_string = NULL;
 
 /*
  * Any really sensitive data in the application is contained in this
@@ -128,43 +118,11 @@ int received_sighup = 0;
    the private key. */
 RSA *public_key;
 
-/* Prototypes for various functions defined later in this file. */
-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);
-void do_exec_pty(const char *command, int ptyfd, int ttyfd,
-	         const char *ttyname, struct passwd * pw, const char *term,
-	         const char *display, const char *auth_proto,
-	         const char *auth_data);
-void do_exec_no_pty(const char *command, struct passwd * pw,
-	            const char *display, const char *auth_proto,
-	            const char *auth_data);
-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);
+/* session identifier, used by RSA-auth */
+unsigned char session_id[16];
 
-/*
- * Remove local Xauthority file.
- */
-void
-xauthfile_cleanup_proc(void *ignore)
-{
-	debug("xauthfile_cleanup_proc called");
-
-	if (xauthfile != NULL) {
-		char *p;
-		unlink(xauthfile);
-		p = strrchr(xauthfile, '/');
-		if (p != NULL) {
-			*p = '\0';
-			rmdir(xauthfile);
-		}
-		xfree(xauthfile);
-		xauthfile = NULL;
-	}
-}
+/* Prototypes for various functions defined later in this file. */
+void do_ssh1_kex();
 
 /*
  * Close all listening sockets
@@ -248,35 +206,6 @@ grace_alarm_handler(int sig)
 }
 
 /*
- * convert ssh auth msg type into description
- */
-char *
-get_authname(int type)
-{
-	static char buf[1024];
-	switch (type) {
-	case SSH_CMSG_AUTH_PASSWORD:
-		return "password";
-	case SSH_CMSG_AUTH_RSA:
-		return "rsa";
-	case SSH_CMSG_AUTH_RHOSTS_RSA:
-		return "rhosts-rsa";
-	case SSH_CMSG_AUTH_RHOSTS:
-		return "rhosts";
-#ifdef KRB4
-	case SSH_CMSG_AUTH_KERBEROS:
-		return "kerberos";
-#endif
-#ifdef SKEY
-	case SSH_CMSG_AUTH_TIS_RESPONSE:
-		return "s/key";
-#endif
-	}
-	snprintf(buf, sizeof buf, "bad-auth-msg-%d", type);
-	return buf;
-}
-
-/*
  * Signal handler for the key regeneration alarm.  Note that this
  * alarm only occurs in the daemon waiting for connections, and it does not
  * do anything with the private key or random state before forking.
@@ -313,6 +242,88 @@ key_regeneration_alarm(int sig)
 	errno = save_errno;
 }
 
+void
+sshd_exchange_identification(int sock_in, int sock_out)
+{
+	int i;
+	int remote_major, remote_minor;
+	char *s;
+	char buf[256];			/* Must not be larger than remote_version. */
+	char remote_version[256];	/* Must be at least as big as buf. */
+
+	snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
+	    PROTOCOL_MAJOR, PROTOCOL_MINOR, SSH_VERSION);
+	server_version_string = xstrdup(buf);
+
+	if (client_version_string == NULL) {
+		/* Send our protocol version identification. */
+		if (atomicio(write, sock_out, server_version_string, strlen(server_version_string))
+		    != strlen(server_version_string)) {
+			log("Could not write ident string to %s.", get_remote_ipaddr());
+			fatal_cleanup();
+		}
+
+		/* Read other side\'s version identification. */
+		for (i = 0; i < sizeof(buf) - 1; i++) {
+			if (read(sock_in, &buf[i], 1) != 1) {
+				log("Did not receive ident string from %s.", get_remote_ipaddr());
+				fatal_cleanup();
+			}
+			if (buf[i] == '\r') {
+				buf[i] = '\n';
+				buf[i + 1] = 0;
+				continue;
+				/*break; XXX eat \r */
+			}
+			if (buf[i] == '\n') {
+				/* buf[i] == '\n' */
+				buf[i + 1] = 0;
+				break;
+			}
+		}
+		buf[sizeof(buf) - 1] = 0;
+		client_version_string = xstrdup(buf);
+	}
+
+	/*
+	 * Check that the versions match.  In future this might accept
+	 * several versions and set appropriate flags to handle them.
+	 */
+	if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
+	    &remote_major, &remote_minor, remote_version) != 3) {
+ 		s = "Protocol mismatch.\n";
+		(void) atomicio(write, sock_out, s, strlen(s));
+		close(sock_in);
+		close(sock_out);
+		log("Bad protocol version identification '%.100s' from %s",
+		    client_version_string, get_remote_ipaddr());
+		fatal_cleanup();
+	}
+	debug("Client protocol version %d.%d; client software version %.100s",
+	      remote_major, remote_minor, remote_version);
+
+	switch(remote_major) {
+	case 1:
+		if (remote_minor < 3) {
+			packet_disconnect("Your ssh version is too old and"
+			    "is no longer supported.  Please install a newer version.");
+		} else if (remote_minor == 3) {
+			/* note that this disables agent-forwarding */
+			enable_compat13();
+		}
+		break;
+	default: 
+		s = "Protocol major versions differ.\n";
+		(void) atomicio(write, sock_out, s, strlen(s));
+		close(sock_in);
+		close(sock_out);
+		log("Protocol major versions differ for %s: %d vs. %d",
+		    get_remote_ipaddr(), PROTOCOL_MAJOR, remote_major);
+		fatal_cleanup();
+		break;
+	}
+}
+
 /*
  * Main program for the daemon.
  */
@@ -323,12 +334,9 @@ main(int ac, char **av)
 	extern int optind;
 	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;
 	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;
 	int remote_port;
 	char *comment;
@@ -791,73 +799,7 @@ main(int ac, char **av)
 	if (!debug_flag)
 		alarm(options.login_grace_time);
 
-	if (client_version_string != NULL) {
-		/* we are exec'ed by sshd2, so skip exchange of protocol version */
-		strlcpy(buf, client_version_string, sizeof(buf));
-	} else {
-		/* Send our protocol version identification. */
-		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)) {
-			log("Could not write ident string to %s.", remote_ip);
-			fatal_cleanup();
-		}
-
-		/* Read other side\'s version identification. */
-		for (i = 0; i < sizeof(buf) - 1; i++) {
-			if (read(sock_in, &buf[i], 1) != 1) {
-				log("Did not receive ident string from %s.", remote_ip);
-				fatal_cleanup();
-			}
-			if (buf[i] == '\r') {
-				buf[i] = '\n';
-				buf[i + 1] = 0;
-				break;
-			}
-			if (buf[i] == '\n') {
-				/* buf[i] == '\n' */
-				buf[i + 1] = 0;
-				break;
-			}
-		}
-		buf[sizeof(buf) - 1] = 0;
-	}
-
-	/*
-	 * Check that the versions match.  In future this might accept
-	 * several versions and set appropriate flags to handle them.
-	 */
-	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n", &remote_major, &remote_minor,
-	    remote_version) != 3) {
-		char *s = "Protocol mismatch.\n";
-
-		(void) atomicio(write, sock_out, s, strlen(s));
-		close(sock_in);
-		close(sock_out);
-		log("Bad protocol version identification '%.100s' from %s",
-		    buf, remote_ip);
-		fatal_cleanup();
-	}
-	debug("Client protocol version %d.%d; client software version %.100s",
-	      remote_major, remote_minor, remote_version);
-	if (remote_major != PROTOCOL_MAJOR) {
-		char *s = "Protocol major versions differ.\n";
-
-		(void) atomicio(write, sock_out, s, strlen(s));
-		close(sock_in);
-		close(sock_out);
-		log("Protocol major versions differ for %s: %d vs. %d",
-		    remote_ip, PROTOCOL_MAJOR, remote_major);
-		fatal_cleanup();
-	}
-	/* 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();
-	}
+	sshd_exchange_identification(sock_in, sock_out);
 	/*
 	 * Check that the connection comes from a privileged port.  Rhosts-
 	 * and Rhosts-RSA-Authentication only make sense from priviledged
@@ -881,8 +823,7 @@ main(int ac, char **av)
 	packet_set_nonblocking();
 
 	/* perform the key exchange */
-	do_ssh_kex();
-
+	do_ssh1_kex();
 	/* authenticate user and start session */
 	do_authentication();
 
@@ -892,10 +833,6 @@ main(int ac, char **av)
 		(void) dest_tkt();
 #endif /* KRB4 */
 
-	/* Cleanup user's local Xauthority file. */
-	if (xauthfile)
-		xauthfile_cleanup_proc(NULL);
-
 	/* The connection has been terminated. */
 	verbose("Closing connection to %.100s", remote_ip);
 	packet_close();
@@ -906,7 +843,7 @@ main(int ac, char **av)
  * SSH1 key exchange
  */
 void
-do_ssh_kex()
+do_ssh1_kex()
 {
 	int i, len;
 	int plen, slen;
@@ -1093,1463 +1030,3 @@ do_ssh_kex()
 	packet_send();
 	packet_write_wait();
 }
-
-
-/*
- * 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
- * be returned. If AllowUsers isn't empty and user isn't listed there, or
- * if AllowGroups isn't empty and user isn't listed there, false will be
- * returned. 
- * If the user's shell is not executable, false will be returned.
- * Otherwise true is returned. 
- */
-static int
-allowed_user(struct passwd * pw)
-{
-	struct stat st;
-	struct group *grp;
-	int i;
-
-	/* Shouldn't be called if pw is NULL, but better safe than sorry... */
-	if (!pw)
-		return 0;
-
-	/* deny if shell does not exists or is not executable */
-	if (stat(pw->pw_shell, &st) != 0)
-		return 0;
-	if (!((st.st_mode & S_IFREG) && (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP))))
-		return 0;
-
-	/* Return false if user is listed in DenyUsers */
-	if (options.num_deny_users > 0) {
-		if (!pw->pw_name)
-			return 0;
-		for (i = 0; i < options.num_deny_users; i++)
-			if (match_pattern(pw->pw_name, options.deny_users[i]))
-				return 0;
-	}
-	/* Return false if AllowUsers isn't empty and user isn't listed there */
-	if (options.num_allow_users > 0) {
-		if (!pw->pw_name)
-			return 0;
-		for (i = 0; i < options.num_allow_users; i++)
-			if (match_pattern(pw->pw_name, options.allow_users[i]))
-				break;
-		/* i < options.num_allow_users iff we break for loop */
-		if (i >= options.num_allow_users)
-			return 0;
-	}
-	/* Get the primary group name if we need it. Return false if it fails */
-	if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
-		grp = getgrgid(pw->pw_gid);
-		if (!grp)
-			return 0;
-
-		/* Return false if user's group is listed in DenyGroups */
-		if (options.num_deny_groups > 0) {
-			if (!grp->gr_name)
-				return 0;
-			for (i = 0; i < options.num_deny_groups; i++)
-				if (match_pattern(grp->gr_name, options.deny_groups[i]))
-					return 0;
-		}
-		/*
-		 * Return false if AllowGroups isn't empty and user's group
-		 * isn't listed there
-		 */
-		if (options.num_allow_groups > 0) {
-			if (!grp->gr_name)
-				return 0;
-			for (i = 0; i < options.num_allow_groups; i++)
-				if (match_pattern(grp->gr_name, options.allow_groups[i]))
-					break;
-			/* i < options.num_allow_groups iff we break for
-			   loop */
-			if (i >= options.num_allow_groups)
-				return 0;
-		}
-	}
-	/* We found no reason not to let this user try to log on... */
-	return 1;
-}
-
-/*
- * Performs authentication of an incoming connection.  Session key has already
- * been exchanged and encryption is enabled.
- */
-void
-do_authentication()
-{
-	struct passwd *pw, pwcopy;
-	int plen;
-	unsigned int 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. */
-	if (k_hasafs()) {
-		k_setpag();
-		k_unlog();
-	}
-#endif /* AFS */
-
-	/* Verify that the user is a valid user. */
-	pw = getpwnam(user);
-	if (!pw || !allowed_user(pw))
-		do_fake_authloop(user);
-	xfree(user);
-
-	/* Take a copy of the returned structure. */
-	memset(&pwcopy, 0, sizeof(pwcopy));
-	pwcopy.pw_name = xstrdup(pw->pw_name);
-	pwcopy.pw_passwd = xstrdup(pw->pw_passwd);
-	pwcopy.pw_uid = pw->pw_uid;
-	pwcopy.pw_gid = pw->pw_gid;
-	pwcopy.pw_dir = xstrdup(pw->pw_dir);
-	pwcopy.pw_shell = xstrdup(pw->pw_shell);
-	pw = &pwcopy;
-
-	/*
-	 * If we are not running as root, the user must have the same uid as
-	 * the server.
-	 */
-	if (getuid() != 0 && pw->pw_uid != getuid())
-		packet_disconnect("Cannot change user when server not running as root.");
-
-	debug("Attempting authentication for %.100s.", pw->pw_name);
-
-	/* If the user has no password, accept authentication immediately. */
-	if (options.password_authentication &&
-#ifdef KRB4
-	    (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
-#endif /* KRB4 */
-	    auth_password(pw, "")) {
-		/* Authentication with empty password succeeded. */
-		log("Login for user %s from %.100s, accepted without authentication.",
-		    pw->pw_name, get_remote_ipaddr());
-	} else {
-		/* Loop until the user has been authenticated or the
-		   connection is closed, do_authloop() returns only if
-		   authentication is successfull */
-		do_authloop(pw);
-	}
-
-	/* The user has been authenticated and accepted. */
-	packet_start(SSH_SMSG_SUCCESS);
-	packet_send();
-	packet_write_wait();
-
-	/* Perform session preparation. */
-	do_authenticated(pw);
-}
-
-#define AUTH_FAIL_MAX 6
-#define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2)
-#define AUTH_FAIL_MSG "Too many authentication failures for %.100s"
-
-/*
- * read packets and try to authenticate local user *pw.
- * return if authentication is successfull
- */
-void
-do_authloop(struct passwd * pw)
-{
-	int attempt = 0;
-	unsigned int bits;
-	RSA *client_host_key;
-	BIGNUM *n;
-	char *client_user, *password;
-	char user[1024];
-	unsigned int dlen;
-	int plen, nlen, elen;
-	unsigned int ulen;
-	int type = 0;
-	void (*authlog) (const char *fmt,...) = verbose;
-
-	/* Indicate that authentication is needed. */
-	packet_start(SSH_SMSG_FAILURE);
-	packet_send();
-	packet_write_wait();
-
-	for (attempt = 1;; attempt++) {
-		int authenticated = 0;
-		strlcpy(user, "", sizeof user);
-
-		/* Get a packet from the client. */
-		type = packet_read(&plen);
-
-		/* Process the packet. */
-		switch (type) {
-#ifdef AFS
-		case SSH_CMSG_HAVE_KERBEROS_TGT:
-			if (!options.kerberos_tgt_passing) {
-				/* packet_get_all(); */
-				verbose("Kerberos tgt passing disabled.");
-				break;
-			} else {
-				/* Accept Kerberos tgt. */
-				char *tgt = packet_get_string(&dlen);
-				packet_integrity_check(plen, 4 + dlen, type);
-				if (!auth_kerberos_tgt(pw, tgt))
-					verbose("Kerberos tgt REFUSED for %s", pw->pw_name);
-				xfree(tgt);
-			}
-			continue;
-
-		case SSH_CMSG_HAVE_AFS_TOKEN:
-			if (!options.afs_token_passing || !k_hasafs()) {
-				/* packet_get_all(); */
-				verbose("AFS token passing disabled.");
-				break;
-			} else {
-				/* Accept AFS token. */
-				char *token_string = packet_get_string(&dlen);
-				packet_integrity_check(plen, 4 + dlen, type);
-				if (!auth_afs_token(pw, token_string))
-					verbose("AFS token REFUSED for %s", pw->pw_name);
-				xfree(token_string);
-			}
-			continue;
-#endif /* AFS */
-#ifdef KRB4
-		case SSH_CMSG_AUTH_KERBEROS:
-			if (!options.kerberos_authentication) {
-				/* packet_get_all(); */
-				verbose("Kerberos authentication disabled.");
-				break;
-			} else {
-				/* Try Kerberos v4 authentication. */
-				KTEXT_ST auth;
-				char *tkt_user = NULL;
-				char *kdata = packet_get_string((unsigned int *) &auth.length);
-				packet_integrity_check(plen, 4 + auth.length, type);
-
-				if (auth.length < MAX_KTXT_LEN)
-					memcpy(auth.dat, kdata, auth.length);
-				xfree(kdata);
-
-				authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user);
-
-				if (authenticated) {
-					snprintf(user, sizeof user, " tktuser %s", tkt_user);
-					xfree(tkt_user);
-				}
-			}
-			break;
-#endif /* KRB4 */
-
-		case SSH_CMSG_AUTH_RHOSTS:
-			if (!options.rhosts_authentication) {
-				verbose("Rhosts authentication disabled.");
-				break;
-			}
-			/*
-			 * Get client user name.  Note that we just have to
-			 * trust the client; this is one reason why rhosts
-			 * authentication is insecure. (Another is
-			 * IP-spoofing on a local network.)
-			 */
-			client_user = packet_get_string(&ulen);
-			packet_integrity_check(plen, 4 + ulen, type);
-
-			/* Try to authenticate using /etc/hosts.equiv and
-			   .rhosts. */
-			authenticated = auth_rhosts(pw, client_user);
-
-			snprintf(user, sizeof user, " ruser %s", client_user);
-			xfree(client_user);
-			break;
-
-		case SSH_CMSG_AUTH_RHOSTS_RSA:
-			if (!options.rhosts_rsa_authentication) {
-				verbose("Rhosts with RSA authentication disabled.");
-				break;
-			}
-			/*
-			 * Get client user name.  Note that we just have to
-			 * trust the client; root on the client machine can
-			 * claim to be any user.
-			 */
-			client_user = packet_get_string(&ulen);
-
-			/* Get the client host key. */
-			client_host_key = RSA_new();
-			if (client_host_key == NULL)
-				fatal("RSA_new failed");
-			client_host_key->e = BN_new();
-			client_host_key->n = BN_new();
-			if (client_host_key->e == NULL || client_host_key->n == NULL)
-				fatal("BN_new failed");
-			bits = packet_get_int();
-			packet_get_bignum(client_host_key->e, &elen);
-			packet_get_bignum(client_host_key->n, &nlen);
-
-			if (bits != BN_num_bits(client_host_key->n))
-				error("Warning: keysize mismatch for client_host_key: "
-				      "actual %d, announced %d", BN_num_bits(client_host_key->n), bits);
-			packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type);
-
-			authenticated = auth_rhosts_rsa(pw, client_user, client_host_key);
-			RSA_free(client_host_key);
-
-			snprintf(user, sizeof user, " ruser %s", client_user);
-			xfree(client_user);
-			break;
-
-		case SSH_CMSG_AUTH_RSA:
-			if (!options.rsa_authentication) {
-				verbose("RSA authentication disabled.");
-				break;
-			}
-			/* RSA authentication requested. */
-			n = BN_new();
-			packet_get_bignum(n, &nlen);
-			packet_integrity_check(plen, nlen, type);
-			authenticated = auth_rsa(pw, n);
-			BN_clear_free(n);
-			break;
-
-		case SSH_CMSG_AUTH_PASSWORD:
-			if (!options.password_authentication) {
-				verbose("Password authentication disabled.");
-				break;
-			}
-			/*
-			 * Read user password.  It is in plain text, but was
-			 * transmitted over the encrypted channel so it is
-			 * not visible to an outside observer.
-			 */
-			password = packet_get_string(&dlen);
-			packet_integrity_check(plen, 4 + dlen, type);
-
-			/* Try authentication with the password. */
-			authenticated = auth_password(pw, password);
-
-			memset(password, 0, strlen(password));
-			xfree(password);
-			break;
-
-#ifdef SKEY
-		case SSH_CMSG_AUTH_TIS:
-			debug("rcvd SSH_CMSG_AUTH_TIS");
-			if (options.skey_authentication == 1) {
-				char *skeyinfo = skey_keyinfo(pw->pw_name);
-				if (skeyinfo == NULL) {
-					debug("generating fake skeyinfo for %.100s.", pw->pw_name);
-					skeyinfo = skey_fake_keyinfo(pw->pw_name);
-				}
-				if (skeyinfo != NULL) {
-					/* we send our s/key- in tis-challenge messages */
-					debug("sending challenge '%s'", skeyinfo);
-					packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
-					packet_put_string(skeyinfo, strlen(skeyinfo));
-					packet_send();
-					packet_write_wait();
-					continue;
-				}
-			}
-			break;
-		case SSH_CMSG_AUTH_TIS_RESPONSE:
-			debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
-			if (options.skey_authentication == 1) {
-				char *response = packet_get_string(&dlen);
-				debug("skey response == '%s'", response);
-				packet_integrity_check(plen, 4 + dlen, type);
-				authenticated = (skey_haskey(pw->pw_name) == 0 &&
-						 skey_passcheck(pw->pw_name, response) != -1);
-				xfree(response);
-			}
-			break;
-#else
-		case SSH_CMSG_AUTH_TIS:
-			/* TIS Authentication is unsupported */
-			log("TIS authentication unsupported.");
-			break;
-#endif
-
-		default:
-			/*
-			 * Any unknown messages will be ignored (and failure
-			 * returned) during authentication.
-			 */
-			log("Unknown message during authentication: type %d", type);
-			break;
-		}
-
-		/*
-		 * Check if the user is logging in as root and root logins
-		 * are disallowed.
-		 * Note that root login is allowed for forced commands.
-		 */
-		if (authenticated && pw->pw_uid == 0 && !options.permit_root_login) {
-			if (forced_command) {
-				log("Root login accepted for forced command.");
-			} else {
-				authenticated = 0;
-				log("ROOT LOGIN REFUSED FROM %.200s",
-				    get_canonical_hostname());
-			}
-		}
-
-		/* Raise logging level */
-		if (authenticated ||
-		    attempt == AUTH_FAIL_LOG ||
-		    type == SSH_CMSG_AUTH_PASSWORD)
-			authlog = log;
-
-		authlog("%s %s for %.200s from %.200s port %d%s",
-			authenticated ? "Accepted" : "Failed",
-			get_authname(type),
-			pw->pw_uid == 0 ? "ROOT" : pw->pw_name,
-			get_remote_ipaddr(),
-			get_remote_port(),
-			user);
-
-		if (authenticated)
-			return;
-
-		if (attempt > AUTH_FAIL_MAX)
-			packet_disconnect(AUTH_FAIL_MSG, pw->pw_name);
-
-		/* Send a message indicating that the authentication attempt failed. */
-		packet_start(SSH_SMSG_FAILURE);
-		packet_send();
-		packet_write_wait();
-	}
-}
-
-/*
- * The user does not exist or access is denied,
- * but fake indication that authentication is needed.
- */
-void
-do_fake_authloop(char *user)
-{
-	int attempt = 0;
-
-	log("Faking authloop for illegal user %.200s from %.200s port %d",
-	    user,
-	    get_remote_ipaddr(),
-	    get_remote_port());
-
-	/* Indicate that authentication is needed. */
-	packet_start(SSH_SMSG_FAILURE);
-	packet_send();
-	packet_write_wait();
-
-	/*
-	 * Keep reading packets, and always respond with a failure.  This is
-	 * to avoid disclosing whether such a user really exists.
-	 */
-	for (attempt = 1;; attempt++) {
-		/* Read a packet.  This will not return if the client disconnects. */
-		int plen;
-		int type = packet_read(&plen);
-#ifdef SKEY
-		unsigned int dlen;
-		char *password, *skeyinfo;
-		/* Try to send a fake s/key challenge. */
-		if (options.skey_authentication == 1 &&
-		    (skeyinfo = skey_fake_keyinfo(user)) != NULL) {
-			password = NULL;
-			if (type == SSH_CMSG_AUTH_TIS) {
-				packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
-				packet_put_string(skeyinfo, strlen(skeyinfo));
-				packet_send();
-				packet_write_wait();
-				continue;
-			} else if (type == SSH_CMSG_AUTH_PASSWORD &&
-			           options.password_authentication &&
-			           (password = packet_get_string(&dlen)) != NULL &&
-			           dlen == 5 &&
-			           strncasecmp(password, "s/key", 5) == 0 ) {
-				packet_send_debug(skeyinfo);
-			}
-			if (password != NULL)
-				xfree(password);
-		}
-#endif
-		if (attempt > AUTH_FAIL_MAX)
-			packet_disconnect(AUTH_FAIL_MSG, user);
-
-		/*
-		 * Send failure.  This should be indistinguishable from a
-		 * failed authentication.
-		 */
-		packet_start(SSH_SMSG_FAILURE);
-		packet_send();
-		packet_write_wait();
-	}
-	/* NOTREACHED */
-	abort();
-}
-
-struct pty_cleanup_context {
-	const char *ttyname;
-	int pid;
-};
-
-/*
- * Function to perform cleanup if we get aborted abnormally (e.g., due to a
- * dropped connection).
- */
-void 
-pty_cleanup_proc(void *context)
-{
-	struct pty_cleanup_context *cu = context;
-
-	debug("pty_cleanup_proc called");
-
-	/* Record that the user has logged out. */
-	record_logout(cu->pid, cu->ttyname);
-
-	/* Release the pseudo-tty. */
-	pty_release(cu->ttyname);
-}
-
-/* simple cleanup: chown tty slave back to root */
-static void
-pty_release_proc(void *tty)
-{
-	char *ttyname = tty;
-	pty_release(ttyname);
-}
-
-/*
- * Prepares for an interactive session.  This is called after the user has
- * been successfully authenticated.  During this message exchange, pseudo
- * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
- * are requested, etc.
- */
-void 
-do_authenticated(struct passwd * pw)
-{
-	int type;
-	int compression_level = 0, enable_compression_after_reply = 0;
-	int have_pty = 0, ptyfd = -1, ttyfd = -1;
-	int row, col, xpixel, ypixel, screen;
-	char ttyname[64];
-	char *command, *term = NULL, *display = NULL, *proto = NULL, *data = NULL;
-	int plen;
-	unsigned int dlen;
-	int n_bytes;
-
-	/*
-	 * Cancel the alarm we set to limit the time taken for
-	 * authentication.
-	 */
-	alarm(0);
-
-	/*
-	 * Inform the channel mechanism that we are the server side and that
-	 * the client may request to connect to any port at all. (The user
-	 * could do it anyway, and we wouldn\'t know what is permitted except
-	 * by the client telling us, so we can equally well trust the client
-	 * not to request anything bogus.)
-	 */
-	if (!no_port_forwarding_flag)
-		channel_permit_all_opens();
-
-	/*
-	 * We stay in this loop until the client requests to execute a shell
-	 * or a command.
-	 */
-	while (1) {
-
-		/* Get a packet from the client. */
-		type = packet_read(&plen);
-
-		/* Process the packet. */
-		switch (type) {
-		case SSH_CMSG_REQUEST_COMPRESSION:
-			packet_integrity_check(plen, 4, type);
-			compression_level = packet_get_int();
-			if (compression_level < 1 || compression_level > 9) {
-				packet_send_debug("Received illegal compression level %d.",
-						  compression_level);
-				goto fail;
-			}
-			/* Enable compression after we have responded with SUCCESS. */
-			enable_compression_after_reply = 1;
-			break;
-
-		case SSH_CMSG_REQUEST_PTY:
-			if (no_pty_flag) {
-				debug("Allocating a pty not permitted for this authentication.");
-				goto fail;
-			}
-			if (have_pty)
-				packet_disconnect("Protocol error: you already have a pty.");
-
-			debug("Allocating pty.");
-
-			/* Allocate a pty and open it. */
-			if (!pty_allocate(&ptyfd, &ttyfd, ttyname,
-			    sizeof(ttyname))) {
-				error("Failed to allocate pty.");
-				goto fail;
-			}
-			fatal_add_cleanup(pty_release_proc, (void *)ttyname);
-			pty_setowner(pw, ttyname);
-
-			/* Get TERM from the packet.  Note that the value may be of arbitrary length. */
-			term = packet_get_string(&dlen);
-			packet_integrity_check(dlen, strlen(term), type);
-
-			/* Remaining bytes */
-			n_bytes = plen - (4 + dlen + 4 * 4);
-
-			if (strcmp(term, "") == 0) {
-				xfree(term);
-				term = NULL;
-			}
-
-			/* Get window size from the packet. */
-			row = packet_get_int();
-			col = packet_get_int();
-			xpixel = packet_get_int();
-			ypixel = packet_get_int();
-			pty_change_window_size(ptyfd, row, col, xpixel, ypixel);
-
-			/* Get tty modes from the packet. */
-			tty_parse_modes(ttyfd, &n_bytes);
-			packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
-
-			/* Indicate that we now have a pty. */
-			have_pty = 1;
-			break;
-
-		case SSH_CMSG_X11_REQUEST_FORWARDING:
-			if (!options.x11_forwarding) {
-				packet_send_debug("X11 forwarding disabled in server configuration file.");
-				goto fail;
-			}
-#ifdef XAUTH_PATH
-			if (no_x11_forwarding_flag) {
-				packet_send_debug("X11 forwarding not permitted for this authentication.");
-				goto fail;
-			}
-			debug("Received request for X11 forwarding with auth spoofing.");
-			if (display)
-				packet_disconnect("Protocol error: X11 display already set.");
-			{
-				unsigned int proto_len, data_len;
-				proto = packet_get_string(&proto_len);
-				data = packet_get_string(&data_len);
-				packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type);
-			}
-			if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER)
-				screen = packet_get_int();
-			else
-				screen = 0;
-			display = x11_create_display_inet(screen, options.x11_display_offset);
-			if (!display)
-				goto fail;
-
-			/* Setup to always have a local .Xauthority. */
-			xauthfile = xmalloc(MAXPATHLEN);
-			strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
-			temporarily_use_uid(pw->pw_uid);
-			if (mkdtemp(xauthfile) == NULL) {
-				restore_uid();
-				error("private X11 dir: mkdtemp %s failed: %s",
-				    xauthfile, strerror(errno));
-				xfree(xauthfile);
-				xauthfile = NULL;
-				goto fail;
-			}
-			strlcat(xauthfile, "/cookies", MAXPATHLEN);
-			open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
-			restore_uid();
-			fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
-			break;
-#else /* XAUTH_PATH */
-			packet_send_debug("No xauth program; cannot forward with spoofing.");
-			goto fail;
-#endif /* XAUTH_PATH */
-
-		case SSH_CMSG_AGENT_REQUEST_FORWARDING:
-			if (no_agent_forwarding_flag || compat13) {
-				debug("Authentication agent forwarding not permitted for this authentication.");
-				goto fail;
-			}
-			debug("Received authentication agent forwarding request.");
-			auth_input_request_forwarding(pw);
-			break;
-
-		case SSH_CMSG_PORT_FORWARD_REQUEST:
-			if (no_port_forwarding_flag) {
-				debug("Port forwarding not permitted for this authentication.");
-				goto fail;
-			}
-			debug("Received TCP/IP port forwarding request.");
-			channel_input_port_forward_request(pw->pw_uid == 0);
-			break;
-
-		case SSH_CMSG_MAX_PACKET_SIZE:
-			if (packet_set_maxsize(packet_get_int()) < 0)
-				goto fail;
-			break;
-
-		case SSH_CMSG_EXEC_SHELL:
-			/* Set interactive/non-interactive mode. */
-			packet_set_interactive(have_pty || display != NULL,
-					       options.keepalives);
-
-			if (forced_command != NULL)
-				goto do_forced_command;
-			debug("Forking shell.");
-			packet_integrity_check(plen, 0, type);
-			if (have_pty)
-				do_exec_pty(NULL, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
-			else
-				do_exec_no_pty(NULL, pw, display, proto, data);
-			return;
-
-		case SSH_CMSG_EXEC_CMD:
-			/* Set interactive/non-interactive mode. */
-			packet_set_interactive(have_pty || display != NULL,
-					       options.keepalives);
-
-			if (forced_command != NULL)
-				goto do_forced_command;
-			/* Get command from the packet. */
-			{
-				unsigned int dlen;
-				command = packet_get_string(&dlen);
-				debug("Executing command '%.500s'", command);
-				packet_integrity_check(plen, 4 + dlen, type);
-			}
-			if (have_pty)
-				do_exec_pty(command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
-			else
-				do_exec_no_pty(command, pw, display, proto, data);
-			xfree(command);
-			return;
-
-		default:
-			/*
-			 * Any unknown messages in this phase are ignored,
-			 * and a failure message is returned.
-			 */
-			log("Unknown packet type received after authentication: %d", type);
-			goto fail;
-		}
-
-		/* The request was successfully processed. */
-		packet_start(SSH_SMSG_SUCCESS);
-		packet_send();
-		packet_write_wait();
-
-		/* Enable compression now that we have replied if appropriate. */
-		if (enable_compression_after_reply) {
-			enable_compression_after_reply = 0;
-			packet_start_compression(compression_level);
-		}
-		continue;
-
-fail:
-		/* The request failed. */
-		packet_start(SSH_SMSG_FAILURE);
-		packet_send();
-		packet_write_wait();
-		continue;
-
-do_forced_command:
-		/*
-		 * There is a forced command specified for this login.
-		 * Execute it.
-		 */
-		debug("Executing forced command: %.900s", forced_command);
-		if (have_pty)
-			do_exec_pty(forced_command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
-		else
-			do_exec_no_pty(forced_command, pw, display, proto, data);
-		return;
-	}
-}
-
-/*
- * This is called to fork and execute a command when we have no tty.  This
- * will call do_child from the child, and server_loop from the parent after
- * setting up file descriptors and such.
- */
-void 
-do_exec_no_pty(const char *command, struct passwd * pw,
-	       const char *display, const char *auth_proto,
-	       const char *auth_data)
-{
-	int pid;
-
-#ifdef USE_PIPES
-	int pin[2], pout[2], perr[2];
-	/* Allocate pipes for communicating with the program. */
-	if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
-		packet_disconnect("Could not create pipes: %.100s",
-				  strerror(errno));
-#else /* USE_PIPES */
-	int inout[2], err[2];
-	/* Uses socket pairs to communicate with the program. */
-	if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
-	    socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
-		packet_disconnect("Could not create socket pairs: %.100s",
-				  strerror(errno));
-#endif /* USE_PIPES */
-
-	setproctitle("%s@notty", pw->pw_name);
-
-	/* Fork the child. */
-	if ((pid = fork()) == 0) {
-		/* Child.  Reinitialize the log since the pid has changed. */
-		log_init(av0, options.log_level, options.log_facility, log_stderr);
-
-		/*
-		 * Create a new session and process group since the 4.4BSD
-		 * setlogin() affects the entire process group.
-		 */
-		if (setsid() < 0)
-			error("setsid failed: %.100s", strerror(errno));
-
-#ifdef USE_PIPES
-		/*
-		 * Redirect stdin.  We close the parent side of the socket
-		 * pair, and make the child side the standard input.
-		 */
-		close(pin[1]);
-		if (dup2(pin[0], 0) < 0)
-			perror("dup2 stdin");
-		close(pin[0]);
-
-		/* Redirect stdout. */
-		close(pout[0]);
-		if (dup2(pout[1], 1) < 0)
-			perror("dup2 stdout");
-		close(pout[1]);
-
-		/* Redirect stderr. */
-		close(perr[0]);
-		if (dup2(perr[1], 2) < 0)
-			perror("dup2 stderr");
-		close(perr[1]);
-#else /* USE_PIPES */
-		/*
-		 * Redirect stdin, stdout, and stderr.  Stdin and stdout will
-		 * use the same socket, as some programs (particularly rdist)
-		 * seem to depend on it.
-		 */
-		close(inout[1]);
-		close(err[1]);
-		if (dup2(inout[0], 0) < 0)	/* stdin */
-			perror("dup2 stdin");
-		if (dup2(inout[0], 1) < 0)	/* stdout.  Note: same socket as stdin. */
-			perror("dup2 stdout");
-		if (dup2(err[0], 2) < 0)	/* stderr */
-			perror("dup2 stderr");
-#endif /* USE_PIPES */
-
-		/* Do processing for the child (exec command etc). */
-		do_child(command, pw, NULL, display, auth_proto, auth_data, NULL);
-		/* NOTREACHED */
-	}
-	if (pid < 0)
-		packet_disconnect("fork failed: %.100s", strerror(errno));
-#ifdef USE_PIPES
-	/* We are the parent.  Close the child sides of the pipes. */
-	close(pin[0]);
-	close(pout[1]);
-	close(perr[1]);
-
-	/* Enter the interactive session. */
-	server_loop(pid, pin[1], pout[0], perr[0]);
-	/* server_loop has closed pin[1], pout[1], and perr[1]. */
-#else /* USE_PIPES */
-	/* We are the parent.  Close the child sides of the socket pairs. */
-	close(inout[0]);
-	close(err[0]);
-
-	/*
-	 * Enter the interactive session.  Note: server_loop must be able to
-	 * handle the case that fdin and fdout are the same.
-	 */
-	server_loop(pid, inout[1], inout[1], err[1]);
-	/* server_loop has closed inout[1] and err[1]. */
-#endif /* USE_PIPES */
-}
-
-/*
- * This is called to fork and execute a command when we have a tty.  This
- * will call do_child from the child, and server_loop from the parent after
- * setting up file descriptors, controlling tty, updating wtmp, utmp,
- * lastlog, and other such operations.
- */
-void 
-do_exec_pty(const char *command, int ptyfd, int ttyfd,
-	    const char *ttyname, struct passwd * pw, const char *term,
-	    const char *display, const char *auth_proto,
-	    const char *auth_data)
-{
-	int pid, fdout;
-	int ptymaster;
-	const char *hostname;
-	time_t last_login_time;
-	char buf[100], *time_string;
-	FILE *f;
-	char line[256];
-	struct stat st;
-	int quiet_login;
-	struct sockaddr_storage from;
-	socklen_t fromlen;
-	struct pty_cleanup_context cleanup_context;
-
-	/* Get remote host name. */
-	hostname = get_canonical_hostname();
-
-	/*
-	 * Get the time when the user last logged in.  Buf will be set to
-	 * contain the hostname the last login was from.
-	 */
-	if (!options.use_login) {
-		last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
-						      buf, sizeof(buf));
-	}
-	setproctitle("%s@%s", pw->pw_name, strrchr(ttyname, '/') + 1);
-
-	/* Fork the child. */
-	if ((pid = fork()) == 0) {
-		pid = getpid();
-
-		/* Child.  Reinitialize the log because the pid has
-		   changed. */
-		log_init(av0, options.log_level, options.log_facility, log_stderr);
-
-		/* Close the master side of the pseudo tty. */
-		close(ptyfd);
-
-		/* Make the pseudo tty our controlling tty. */
-		pty_make_controlling_tty(&ttyfd, ttyname);
-
-		/* Redirect stdin from the pseudo tty. */
-		if (dup2(ttyfd, fileno(stdin)) < 0)
-			error("dup2 stdin failed: %.100s", strerror(errno));
-
-		/* Redirect stdout to the pseudo tty. */
-		if (dup2(ttyfd, fileno(stdout)) < 0)
-			error("dup2 stdin failed: %.100s", strerror(errno));
-
-		/* Redirect stderr to the pseudo tty. */
-		if (dup2(ttyfd, fileno(stderr)) < 0)
-			error("dup2 stdin failed: %.100s", strerror(errno));
-
-		/* Close the extra descriptor for the pseudo tty. */
-		close(ttyfd);
-
-		/*
-		 * Get IP address of client.  This is needed because we want
-		 * to record where the user logged in from.  If the
-		 * connection is not a socket, let the ip address be 0.0.0.0.
-		 */
-		memset(&from, 0, sizeof(from));
-		if (packet_get_connection_in() == packet_get_connection_out()) {
-			fromlen = sizeof(from);
-			if (getpeername(packet_get_connection_in(),
-			     (struct sockaddr *) & from, &fromlen) < 0) {
-				debug("getpeername: %.100s", strerror(errno));
-				fatal_cleanup();
-			}
-		}
-		/* Record that there was a login on that terminal. */
-		record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname,
-			     (struct sockaddr *)&from);
-
-		/* Check if .hushlogin exists. */
-		snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir);
-		quiet_login = stat(line, &st) >= 0;
-
-		/*
-		 * If the user has logged in before, display the time of last
-		 * login. However, don't display anything extra if a command
-		 * has been specified (so that ssh can be used to execute
-		 * commands on a remote machine without users knowing they
-		 * are going to another machine). Login(1) will do this for
-		 * us as well, so check if login(1) is used
-		 */
-		if (command == NULL && last_login_time != 0 && !quiet_login &&
-		    !options.use_login) {
-			/* Convert the date to a string. */
-			time_string = ctime(&last_login_time);
-			/* Remove the trailing newline. */
-			if (strchr(time_string, '\n'))
-				*strchr(time_string, '\n') = 0;
-			/* Display the last login time.  Host if displayed
-			   if known. */
-			if (strcmp(buf, "") == 0)
-				printf("Last login: %s\r\n", time_string);
-			else
-				printf("Last login: %s from %s\r\n", time_string, buf);
-		}
-		/*
-		 * Print /etc/motd unless a command was specified or printing
-		 * it was disabled in server options or login(1) will be
-		 * used.  Note that some machines appear to print it in
-		 * /etc/profile or similar.
-		 */
-		if (command == NULL && options.print_motd && !quiet_login &&
-		    !options.use_login) {
-			/* Print /etc/motd if it exists. */
-			f = fopen("/etc/motd", "r");
-			if (f) {
-				while (fgets(line, sizeof(line), f))
-					fputs(line, stdout);
-				fclose(f);
-			}
-		}
-		/* Do common processing for the child, such as execing the command. */
-		do_child(command, pw, term, display, auth_proto, auth_data, ttyname);
-		/* NOTREACHED */
-	}
-	if (pid < 0)
-		packet_disconnect("fork failed: %.100s", strerror(errno));
-	/* Parent.  Close the slave side of the pseudo tty. */
-	close(ttyfd);
-
-	/*
-	 * Add a cleanup function to clear the utmp entry and record logout
-	 * time in case we call fatal() (e.g., the connection gets closed).
-	 */
-	cleanup_context.pid = pid;
-	cleanup_context.ttyname = ttyname;
-	fatal_add_cleanup(pty_cleanup_proc, (void *) &cleanup_context);
-	fatal_remove_cleanup(pty_release_proc, (void *) ttyname);
-
-	/*
-	 * Create another descriptor of the pty master side for use as the
-	 * standard input.  We could use the original descriptor, but this
-	 * simplifies code in server_loop.  The descriptor is bidirectional.
-	 */
-	fdout = dup(ptyfd);
-	if (fdout < 0)
-		packet_disconnect("dup #1 failed: %.100s", strerror(errno));
-
-	/* we keep a reference to the pty master */
-	ptymaster = dup(ptyfd);
-	if (ptymaster < 0)
-		packet_disconnect("dup #2 failed: %.100s", strerror(errno));
-
-	/* Enter interactive session. */
-	server_loop(pid, ptyfd, fdout, -1);
-	/* server_loop _has_ closed ptyfd and fdout. */
-
-	/* Cancel the cleanup function. */
-	fatal_remove_cleanup(pty_cleanup_proc, (void *) &cleanup_context);
-
-	/* Record that the user has logged out. */
-	record_logout(pid, ttyname);
-
-	/* Release the pseudo-tty. */
-	pty_release(ttyname);
-
-	/*
-	 * Close the server side of the socket pairs.  We must do this after
-	 * the pty cleanup, so that another process doesn't get this pty
-	 * while we're still cleaning up.
-	 */
-	if (close(ptymaster) < 0)
-		error("close(ptymaster): %s", strerror(errno));
-}
-
-/*
- * Sets the value of the given variable in the environment.  If the variable
- * already exists, its value is overriden.
- */
-void 
-child_set_env(char ***envp, unsigned int *envsizep, const char *name,
-	      const char *value)
-{
-	unsigned int i, namelen;
-	char **env;
-
-	/*
-	 * Find the slot where the value should be stored.  If the variable
-	 * already exists, we reuse the slot; otherwise we append a new slot
-	 * at the end of the array, expanding if necessary.
-	 */
-	env = *envp;
-	namelen = strlen(name);
-	for (i = 0; env[i]; i++)
-		if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
-			break;
-	if (env[i]) {
-		/* Reuse the slot. */
-		xfree(env[i]);
-	} else {
-		/* New variable.  Expand if necessary. */
-		if (i >= (*envsizep) - 1) {
-			(*envsizep) += 50;
-			env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
-		}
-		/* Need to set the NULL pointer at end of array beyond the new slot. */
-		env[i + 1] = NULL;
-	}
-
-	/* Allocate space and format the variable in the appropriate slot. */
-	env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
-	snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
-}
-
-/*
- * Reads environment variables from the given file and adds/overrides them
- * into the environment.  If the file does not exist, this does nothing.
- * Otherwise, it must consist of empty lines, comments (line starts with '#')
- * and assignments of the form name=value.  No other forms are allowed.
- */
-void 
-read_environment_file(char ***env, unsigned int *envsize,
-		      const char *filename)
-{
-	FILE *f;
-	char buf[4096];
-	char *cp, *value;
-
-	f = fopen(filename, "r");
-	if (!f)
-		return;
-
-	while (fgets(buf, sizeof(buf), f)) {
-		for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
-			;
-		if (!*cp || *cp == '#' || *cp == '\n')
-			continue;
-		if (strchr(cp, '\n'))
-			*strchr(cp, '\n') = '\0';
-		value = strchr(cp, '=');
-		if (value == NULL) {
-			fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
-			continue;
-		}
-		/* Replace the equals sign by nul, and advance value to the value string. */
-		*value = '\0';
-		value++;
-		child_set_env(env, envsize, cp, value);
-	}
-	fclose(f);
-}
-
-/*
- * Performs common processing for the child, such as setting up the
- * environment, closing extra file descriptors, setting the user and group
- * ids, and executing the command or shell.
- */
-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)
-{
-	const char *shell, *cp = NULL;
-	char buf[256];
-	FILE *f;
-	unsigned int envsize, i;
-	char **env;
-	extern char **environ;
-	struct stat st;
-	char *argv[10];
-
-	f = fopen("/etc/nologin", "r");
-	if (f) {
-		/* /etc/nologin exists.  Print its contents and exit. */
-		while (fgets(buf, sizeof(buf), f))
-			fputs(buf, stderr);
-		fclose(f);
-		if (pw->pw_uid != 0)
-			exit(254);
-	}
-	/* Set login name in the kernel. */
-	if (setlogin(pw->pw_name) < 0)
-		error("setlogin failed: %s", strerror(errno));
-
-	/* Set uid, gid, and groups. */
-	/* Login(1) does this as well, and it needs uid 0 for the "-h"
-	   switch, so we let login(1) to this for us. */
-	if (!options.use_login) {
-		if (getuid() == 0 || geteuid() == 0) {
-			if (setgid(pw->pw_gid) < 0) {
-				perror("setgid");
-				exit(1);
-			}
-			/* Initialize the group list. */
-			if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
-				perror("initgroups");
-				exit(1);
-			}
-			endgrent();
-
-			/* Permanently switch to the desired uid. */
-			permanently_set_uid(pw->pw_uid);
-		}
-		if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
-			fatal("Failed to set uids to %d.", (int) pw->pw_uid);
-	}
-	/*
-	 * Get the shell from the password data.  An empty shell field is
-	 * legal, and means /bin/sh.
-	 */
-	shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
-
-#ifdef AFS
-	/* Try to get AFS tokens for the local cell. */
-	if (k_hasafs()) {
-		char cell[64];
-
-		if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
-			krb_afslog(cell, 0);
-
-		krb_afslog(0, 0);
-	}
-#endif /* AFS */
-
-	/* Initialize the environment. */
-	envsize = 100;
-	env = xmalloc(envsize * sizeof(char *));
-	env[0] = NULL;
-
-	if (!options.use_login) {
-		/* Set basic environment. */
-		child_set_env(&env, &envsize, "USER", pw->pw_name);
-		child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
-		child_set_env(&env, &envsize, "HOME", pw->pw_dir);
-		child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
-
-		snprintf(buf, sizeof buf, "%.200s/%.50s",
-			 _PATH_MAILDIR, pw->pw_name);
-		child_set_env(&env, &envsize, "MAIL", buf);
-
-		/* Normal systems set SHELL by default. */
-		child_set_env(&env, &envsize, "SHELL", shell);
-	}
-	if (getenv("TZ"))
-		child_set_env(&env, &envsize, "TZ", getenv("TZ"));
-
-	/* Set custom environment options from RSA authentication. */
-	while (custom_environment) {
-		struct envstring *ce = custom_environment;
-		char *s = ce->s;
-		int i;
-		for (i = 0; s[i] != '=' && s[i]; i++);
-		if (s[i] == '=') {
-			s[i] = 0;
-			child_set_env(&env, &envsize, s, s + i + 1);
-		}
-		custom_environment = ce->next;
-		xfree(ce->s);
-		xfree(ce);
-	}
-
-	snprintf(buf, sizeof buf, "%.50s %d %d",
-		 get_remote_ipaddr(), get_remote_port(), get_local_port());
-	child_set_env(&env, &envsize, "SSH_CLIENT", buf);
-
-	if (ttyname)
-		child_set_env(&env, &envsize, "SSH_TTY", ttyname);
-	if (term)
-		child_set_env(&env, &envsize, "TERM", term);
-	if (display)
-		child_set_env(&env, &envsize, "DISPLAY", display);
-
-#ifdef KRB4
-	{
-		extern char *ticket;
-
-		if (ticket)
-			child_set_env(&env, &envsize, "KRBTKFILE", ticket);
-	}
-#endif /* KRB4 */
-
-	if (xauthfile)
-		child_set_env(&env, &envsize, "XAUTHORITY", xauthfile);
-	if (auth_get_socket_name() != NULL)
-		child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
-			      auth_get_socket_name());
-
-	/* read $HOME/.ssh/environment. */
-	if (!options.use_login) {
-		snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir);
-		read_environment_file(&env, &envsize, buf);
-	}
-	if (debug_flag) {
-		/* dump the environment */
-		fprintf(stderr, "Environment:\n");
-		for (i = 0; env[i]; i++)
-			fprintf(stderr, "  %.200s\n", env[i]);
-	}
-	/*
-	 * Close the connection descriptors; note that this is the child, and
-	 * the server will still have the socket open, and it is important
-	 * that we do not shutdown it.  Note that the descriptors cannot be
-	 * closed before building the environment, as we call
-	 * get_remote_ipaddr there.
-	 */
-	if (packet_get_connection_in() == packet_get_connection_out())
-		close(packet_get_connection_in());
-	else {
-		close(packet_get_connection_in());
-		close(packet_get_connection_out());
-	}
-	/*
-	 * Close all descriptors related to channels.  They will still remain
-	 * open in the parent.
-	 */
-	/* XXX better use close-on-exec? -markus */
-	channel_close_all();
-
-	/*
-	 * Close any extra file descriptors.  Note that there may still be
-	 * descriptors left by system functions.  They will be closed later.
-	 */
-	endpwent();
-
-	/*
-	 * Close any extra open file descriptors so that we don\'t have them
-	 * hanging around in clients.  Note that we want to do this after
-	 * initgroups, because at least on Solaris 2.3 it leaves file
-	 * descriptors open.
-	 */
-	for (i = 3; i < 64; i++)
-		close(i);
-
-	/* Change current directory to the user\'s home directory. */
-	if (chdir(pw->pw_dir) < 0)
-		fprintf(stderr, "Could not chdir to home directory %s: %s\n",
-			pw->pw_dir, strerror(errno));
-
-	/*
-	 * Must take new environment into use so that .ssh/rc, /etc/sshrc and
-	 * xauth are run in the proper environment.
-	 */
-	environ = env;
-
-	/*
-	 * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first
-	 * in this order).
-	 */
-	if (!options.use_login) {
-		if (stat(SSH_USER_RC, &st) >= 0) {
-			if (debug_flag)
-				fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC);
-
-			f = popen("/bin/sh " SSH_USER_RC, "w");
-			if (f) {
-				if (auth_proto != NULL && auth_data != NULL)
-					fprintf(f, "%s %s\n", auth_proto, auth_data);
-				pclose(f);
-			} else
-				fprintf(stderr, "Could not run %s\n", SSH_USER_RC);
-		} else if (stat(SSH_SYSTEM_RC, &st) >= 0) {
-			if (debug_flag)
-				fprintf(stderr, "Running /bin/sh %s\n", SSH_SYSTEM_RC);
-
-			f = popen("/bin/sh " SSH_SYSTEM_RC, "w");
-			if (f) {
-				if (auth_proto != NULL && auth_data != NULL)
-					fprintf(f, "%s %s\n", auth_proto, auth_data);
-				pclose(f);
-			} else
-				fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC);
-		}
-#ifdef XAUTH_PATH
-		else {
-			/* Add authority data to .Xauthority if appropriate. */
-			if (auth_proto != NULL && auth_data != NULL) {
-				if (debug_flag)
-					fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n",
-						XAUTH_PATH, display, auth_proto, auth_data);
-
-				f = popen(XAUTH_PATH " -q -", "w");
-				if (f) {
-					fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data);
-					pclose(f);
-				} else
-					fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH);
-			}
-		}
-#endif /* XAUTH_PATH */
-
-		/* Get the last component of the shell name. */
-		cp = strrchr(shell, '/');
-		if (cp)
-			cp++;
-		else
-			cp = shell;
-	}
-	/*
-	 * If we have no command, execute the shell.  In this case, the shell
-	 * name to be passed in argv[0] is preceded by '-' to indicate that
-	 * this is a login shell.
-	 */
-	if (!command) {
-		if (!options.use_login) {
-			char buf[256];
-
-			/*
-			 * Check for mail if we have a tty and it was enabled
-			 * in server options.
-			 */
-			if (ttyname && options.check_mail) {
-				char *mailbox;
-				struct stat mailstat;
-				mailbox = getenv("MAIL");
-				if (mailbox != NULL) {
-					if (stat(mailbox, &mailstat) != 0 || mailstat.st_size == 0)
-						printf("No mail.\n");
-					else if (mailstat.st_mtime < mailstat.st_atime)
-						printf("You have mail.\n");
-					else
-						printf("You have new mail.\n");
-				}
-			}
-			/* Start the shell.  Set initial character to '-'. */
-			buf[0] = '-';
-			strncpy(buf + 1, cp, sizeof(buf) - 1);
-			buf[sizeof(buf) - 1] = 0;
-
-			/* Execute the shell. */
-			argv[0] = buf;
-			argv[1] = NULL;
-			execve(shell, argv, env);
-
-			/* Executing the shell failed. */
-			perror(shell);
-			exit(1);
-
-		} else {
-			/* Launch login(1). */
-
-			execl("/usr/bin/login", "login", "-h", get_remote_ipaddr(),
-			      "-p", "-f", "--", pw->pw_name, NULL);
-
-			/* Login couldn't be executed, die. */
-
-			perror("login");
-			exit(1);
-		}
-	}
-	/*
-	 * Execute the command using the user's shell.  This uses the -c
-	 * option to execute the command.
-	 */
-	argv[0] = (char *) cp;
-	argv[1] = "-c";
-	argv[2] = (char *) command;
-	argv[3] = NULL;
-	execve(shell, argv, env);
-	perror(shell);
-	exit(1);
-}