*/
#include "includes.h"
-RCSID("$Id$");
+RCSID("$OpenBSD: sshd.c,v 1.79 2000/01/18 13:45:05 markus Exp $");
#include "xmalloc.h"
#include "rsa.h"
/* 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
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,
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);
const char *display, const char *auth_proto,
const char *auth_data, const char *ttyname);
+/*
+ * Close all listening sockets
+ */
+void
+close_listen_socks(void)
+{
+ int i;
+ for (i = 0; i < num_listen_socks; i++)
+ close(listen_socks[i]);
+ num_listen_socks = -1;
+}
+
/*
* Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
* the effect is to reread the configuration file (and to regenerate
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);
sigterm_handler(int sig)
{
log("Received signal %d; terminating.", sig);
- close(listen_sock);
+ close_listen_socks();
exit(255);
}
{
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;
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;
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;
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);
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)
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);
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
}
}
- 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();
/* 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.
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;
}
/*
* 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();
* 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);
/* 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;
}
}
/* Check whether logins are denied from this host. */
#ifdef LIBWRAP
+ /* XXX LIBWRAP noes not know about IPv6 */
{
struct request_info req;
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
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;
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);
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-
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. */
}
/*
- * 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;
/*
for (i = 0; i < 8; i++) {
if (i % 4 == 0)
rand = arc4random();
- check_bytes[i] = rand & 0xff;
+ cookie[i] = rand & 0xff;
rand >>= 8;
}
*/
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));
/* 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));
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
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);
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
/*
* 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. */
#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;
}
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. */
}
/* 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);
}
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)
* 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
andersk / openssh.git / blobdiff