Initial revision
diff --git a/ssh.c b/ssh.c
new file mode 100644
index 0000000..c5a92b5
--- /dev/null
+++ b/ssh.c
@@ -0,0 +1,809 @@
+/*
+
+ssh.c
+
+Author: Tatu Ylonen <ylo@cs.hut.fi>
+
+Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ All rights reserved
+
+Created: Sat Mar 18 16:36:11 1995 ylo
+
+Ssh client program. This program can be used to log into a remote machine.
+The software supports strong authentication, encryption, and forwarding
+of X11, TCP/IP, and authentication connections.
+
+Modified to work with SSL by Niels Provos <provos@citi.umich.edu> in Canada.
+
+*/
+
+#include "includes.h"
+RCSID("$Id: ssh.c,v 1.1 1999/10/27 03:42:45 damien Exp $");
+
+#include "xmalloc.h"
+#include "ssh.h"
+#include "packet.h"
+#include "buffer.h"
+#include "authfd.h"
+#include "readconf.h"
+#include "uidswap.h"
+
+/* Flag indicating whether debug mode is on. This can be set on the
+ command line. */
+int debug_flag = 0;
+
+/* Flag indicating whether quiet mode is on. */
+int quiet_flag = 0;
+
+/* Flag indicating whether to allocate a pseudo tty. This can be set on the
+ command line, and is automatically set if no command is given on the command
+ line. */
+int tty_flag = 0;
+
+/* Flag indicating that nothing should be read from stdin. This can be set
+ on the command line. */
+int stdin_null_flag = 0;
+
+/* Flag indicating that ssh should fork after authentication. This is useful
+ so that the pasphrase can be entered manually, and then ssh goes to the
+ background. */
+int fork_after_authentication_flag = 0;
+
+/* General data structure for command line options and options configurable
+ in configuration files. See readconf.h. */
+Options options;
+
+/* Name of the host we are connecting to. This is the name given on the
+ command line, or the HostName specified for the user-supplied name
+ in a configuration file. */
+char *host;
+
+/* socket address the host resolves to */
+struct sockaddr_in hostaddr;
+
+/* Flag to indicate that we have received a window change signal which has
+ not yet been processed. This will cause a message indicating the new
+ window size to be sent to the server a little later. This is volatile
+ because this is updated in a signal handler. */
+volatile int received_window_change_signal = 0;
+
+/* Value of argv[0] (set in the main program). */
+char *av0;
+
+/* Flag indicating whether we have a valid host private key loaded. */
+int host_private_key_loaded = 0;
+
+/* Host private key. */
+RSA *host_private_key = NULL;
+
+/* Original real UID. */
+uid_t original_real_uid;
+
+/* Prints a help message to the user. This function never returns. */
+
+void
+usage()
+{
+ fprintf(stderr, "Usage: %s [options] host [command]\n", av0);
+ fprintf(stderr, "Options:\n");
+ fprintf(stderr, " -l user Log in using this user name.\n");
+ fprintf(stderr, " -n Redirect input from /dev/null.\n");
+ fprintf(stderr, " -a Disable authentication agent forwarding.\n");
+#ifdef AFS
+ fprintf(stderr, " -k Disable Kerberos ticket and AFS token forwarding.\n");
+#endif /* AFS */
+ fprintf(stderr, " -x Disable X11 connection forwarding.\n");
+ fprintf(stderr, " -i file Identity for RSA authentication (default: ~/.ssh/identity).\n");
+ fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n");
+ fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
+ fprintf(stderr, " -V Display version number only.\n");
+ fprintf(stderr, " -P Don't allocate a privileged port.\n");
+ fprintf(stderr, " -q Quiet; don't display any warning messages.\n");
+ fprintf(stderr, " -f Fork into background after authentication.\n");
+ fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n");
+
+ fprintf(stderr, " -c cipher Select encryption algorithm: "
+ "``3des'', "
+ "``blowfish''\n");
+ fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n");
+ fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n");
+ fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n");
+ fprintf(stderr, " These cause %s to listen for connections on a port, and\n", av0);
+ fprintf(stderr, " forward them to the other side by connecting to host:port.\n");
+ fprintf(stderr, " -C Enable compression.\n");
+ fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n");
+ fprintf(stderr, " -o 'option' Process the option as if it was read from a configuration file.\n");
+ exit(1);
+}
+
+/* Connects to the given host using rsh (or prints an error message and exits
+ if rsh is not available). This function never returns. */
+
+void
+rsh_connect(char *host, char *user, Buffer *command)
+{
+ char *args[10];
+ int i;
+
+ log("Using rsh. WARNING: Connection will not be encrypted.");
+ /* Build argument list for rsh. */
+ i = 0;
+ args[i++] = _PATH_RSH;
+ args[i++] = host; /* may have to come after user on some systems */
+ if (user)
+ {
+ args[i++] = "-l";
+ args[i++] = user;
+ }
+ if (buffer_len(command) > 0)
+ {
+ buffer_append(command, "\0", 1);
+ args[i++] = buffer_ptr(command);
+ }
+ args[i++] = NULL;
+ if (debug_flag)
+ {
+ for (i = 0; args[i]; i++)
+ {
+ if (i != 0)
+ fprintf(stderr, " ");
+ fprintf(stderr, "%s", args[i]);
+ }
+ fprintf(stderr, "\n");
+ }
+ execv(_PATH_RSH, args);
+ perror(_PATH_RSH);
+ exit(1);
+}
+
+/* Main program for the ssh client. */
+
+uid_t original_real_uid;
+
+int
+main(int ac, char **av)
+{
+ int i, opt, optind, type, exit_status, ok, fwd_port, fwd_host_port, authfd;
+ char *optarg, *cp, buf[256];
+ Buffer command;
+ struct winsize ws;
+ struct stat st;
+ struct passwd *pw, pwcopy;
+ int interactive = 0, dummy;
+ uid_t original_effective_uid;
+ int plen;
+
+ /* Save the original real uid. It will be needed later (uid-swapping may
+ clobber the real uid). */
+ original_real_uid = getuid();
+ original_effective_uid = geteuid();
+
+ /* If we are installed setuid root be careful to not drop core. */
+ if (original_real_uid != original_effective_uid)
+ {
+ struct rlimit rlim;
+ rlim.rlim_cur = rlim.rlim_max = 0;
+ if (setrlimit(RLIMIT_CORE, &rlim) < 0)
+ fatal("setrlimit failed: %.100s", strerror(errno));
+ }
+
+ /* Use uid-swapping to give up root privileges for the duration of option
+ processing. We will re-instantiate the rights when we are ready to
+ create the privileged port, and will permanently drop them when the
+ port has been created (actually, when the connection has been made, as
+ we may need to create the port several times). */
+ temporarily_use_uid(original_real_uid);
+
+ /* Set our umask to something reasonable, as some files are created with
+ the default umask. This will make them world-readable but writable
+ only by the owner, which is ok for all files for which we don't set
+ the modes explicitly. */
+ umask(022);
+
+ /* Save our own name. */
+ av0 = av[0];
+
+ /* Initialize option structure to indicate that no values have been set. */
+ initialize_options(&options);
+
+ /* Parse command-line arguments. */
+ host = NULL;
+
+ /* If program name is not one of the standard names, use it as host name. */
+ if (strchr(av0, '/'))
+ cp = strrchr(av0, '/') + 1;
+ else
+ cp = av0;
+ if (strcmp(cp, "rsh") != 0 && strcmp(cp, "ssh") != 0 &&
+ strcmp(cp, "rlogin") != 0 && strcmp(cp, "slogin") != 0)
+ host = cp;
+
+ for (optind = 1; optind < ac; optind++)
+ {
+ if (av[optind][0] != '-')
+ {
+ if (host)
+ break;
+ if ((cp = strchr(av[optind], '@'))) {
+ options.user = av[optind];
+ *cp = '\0';
+ host = ++cp;
+ }
+ else
+ host = av[optind];
+ continue;
+ }
+ opt = av[optind][1];
+ if (!opt)
+ usage();
+ if (strchr("eilcpLRo", opt)) /* options with arguments */
+ {
+ optarg = av[optind] + 2;
+ if (strcmp(optarg, "") == 0)
+ {
+ if (optind >= ac - 1)
+ usage();
+ optarg = av[++optind];
+ }
+ }
+ else
+ {
+ if (av[optind][2])
+ usage();
+ optarg = NULL;
+ }
+ switch (opt)
+ {
+ case 'n':
+ stdin_null_flag = 1;
+ break;
+
+ case 'f':
+ fork_after_authentication_flag = 1;
+ stdin_null_flag = 1;
+ break;
+
+ case 'x':
+ options.forward_x11 = 0;
+ break;
+
+ case 'X':
+ options.forward_x11 = 1;
+ break;
+
+ case 'g':
+ options.gateway_ports = 1;
+ break;
+
+ case 'P':
+ options.use_privileged_port = 0;
+ break;
+
+ case 'a':
+ options.forward_agent = 0;
+ break;
+#ifdef AFS
+ case 'k':
+ options.kerberos_tgt_passing = 0;
+ options.afs_token_passing = 0;
+ break;
+#endif
+ case 'i':
+ if (stat(optarg, &st) < 0)
+ {
+ fprintf(stderr, "Warning: Identity file %s does not exist.\n",
+ optarg);
+ break;
+ }
+ if (options.num_identity_files >= SSH_MAX_IDENTITY_FILES)
+ fatal("Too many identity files specified (max %d)",
+ SSH_MAX_IDENTITY_FILES);
+ options.identity_files[options.num_identity_files++] =
+ xstrdup(optarg);
+ break;
+
+ case 't':
+ tty_flag = 1;
+ break;
+
+ case 'v':
+ case 'V':
+ debug_flag = 1;
+ fprintf(stderr, "SSH Version %s, protocol version %d.%d.\n",
+ SSH_VERSION, PROTOCOL_MAJOR, PROTOCOL_MINOR);
+ fprintf(stderr, "Compiled with SSL.\n");
+ if (opt == 'V')
+ exit(0);
+ break;
+
+ case 'q':
+ quiet_flag = 1;
+ break;
+
+ case 'e':
+ if (optarg[0] == '^' && optarg[2] == 0 &&
+ (unsigned char)optarg[1] >= 64 && (unsigned char)optarg[1] < 128)
+ options.escape_char = (unsigned char)optarg[1] & 31;
+ else
+ if (strlen(optarg) == 1)
+ options.escape_char = (unsigned char)optarg[0];
+ else
+ if (strcmp(optarg, "none") == 0)
+ options.escape_char = -2;
+ else
+ {
+ fprintf(stderr, "Bad escape character '%s'.\n", optarg);
+ exit(1);
+ }
+ break;
+
+ case 'c':
+ options.cipher = cipher_number(optarg);
+ if (options.cipher == -1)
+ {
+ fprintf(stderr, "Unknown cipher type '%s'\n", optarg);
+ exit(1);
+ }
+ break;
+
+ case 'p':
+ options.port = atoi(optarg);
+ if (options.port < 1 || options.port > 65535)
+ {
+ fprintf(stderr, "Bad port %s.\n", optarg);
+ exit(1);
+ }
+ break;
+
+ case 'l':
+ options.user = optarg;
+ break;
+
+ case 'R':
+ if (sscanf(optarg, "%d:%255[^:]:%d", &fwd_port, buf,
+ &fwd_host_port) != 3)
+ {
+ fprintf(stderr, "Bad forwarding specification '%s'.\n", optarg);
+ usage();
+ /*NOTREACHED*/
+ }
+ add_remote_forward(&options, fwd_port, buf, fwd_host_port);
+ break;
+
+ case 'L':
+ if (sscanf(optarg, "%d:%255[^:]:%d", &fwd_port, buf,
+ &fwd_host_port) != 3)
+ {
+ fprintf(stderr, "Bad forwarding specification '%s'.\n", optarg);
+ usage();
+ /*NOTREACHED*/
+ }
+ add_local_forward(&options, fwd_port, buf, fwd_host_port);
+ break;
+
+ case 'C':
+ options.compression = 1;
+ break;
+
+ case 'o':
+ dummy = 1;
+ process_config_line(&options, host ? host : "", optarg,
+ "command-line", 0, &dummy);
+ break;
+
+ default:
+ usage();
+ }
+ }
+
+ /* Check that we got a host name. */
+ if (!host)
+ usage();
+
+ /* check if RSA support exists */
+ if (rsa_alive() == 0) {
+ extern char *__progname;
+
+ fprintf(stderr,
+ "%s: no RSA support in libssl and libcrypto. See ssl(8).\n",
+ __progname);
+ exit(1);
+ }
+
+ /* Initialize the command to execute on remote host. */
+ buffer_init(&command);
+
+ /* Save the command to execute on the remote host in a buffer. There is
+ no limit on the length of the command, except by the maximum packet
+ size. Also sets the tty flag if there is no command. */
+ if (optind == ac)
+ {
+ /* No command specified - execute shell on a tty. */
+ tty_flag = 1;
+ }
+ else
+ {
+ /* A command has been specified. Store it into the buffer. */
+ for (i = optind; i < ac; i++)
+ {
+ if (i > optind)
+ buffer_append(&command, " ", 1);
+ buffer_append(&command, av[i], strlen(av[i]));
+ }
+ }
+
+ /* Cannot fork to background if no command. */
+ if (fork_after_authentication_flag && buffer_len(&command) == 0)
+ fatal("Cannot fork into background without a command to execute.");
+
+ /* Allocate a tty by default if no command specified. */
+ if (buffer_len(&command) == 0)
+ tty_flag = 1;
+
+ /* Do not allocate a tty if stdin is not a tty. */
+ if (!isatty(fileno(stdin)))
+ {
+ if (tty_flag)
+ fprintf(stderr, "Pseudo-terminal will not be allocated because stdin is not a terminal.\n");
+ tty_flag = 0;
+ }
+
+ /* Get user data. */
+ pw = getpwuid(original_real_uid);
+ if (!pw)
+ {
+ fprintf(stderr, "You don't exist, go away!\n");
+ exit(1);
+ }
+
+ /* 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;
+
+ /* Initialize "log" output. Since we are the client all output actually
+ goes to the terminal. */
+ log_init(av[0], 1, debug_flag, quiet_flag, SYSLOG_FACILITY_USER);
+
+ /* Read per-user configuration file. */
+ snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, SSH_USER_CONFFILE);
+ read_config_file(buf, host, &options);
+
+ /* Read systemwide configuration file. */
+ read_config_file(HOST_CONFIG_FILE, host, &options);
+
+ /* Fill configuration defaults. */
+ fill_default_options(&options);
+ if (options.user == NULL)
+ options.user = xstrdup(pw->pw_name);
+
+ if (options.hostname != NULL)
+ host = options.hostname;
+
+ /* Find canonic host name. */
+ if (strchr(host, '.') == 0)
+ {
+ struct hostent *hp = gethostbyname(host);
+ if (hp != 0)
+ {
+ if (strchr(hp->h_name, '.') != 0)
+ host = xstrdup(hp->h_name);
+ else if (hp->h_aliases != 0
+ && hp->h_aliases[0] != 0
+ && strchr(hp->h_aliases[0], '.') != 0)
+ host = xstrdup(hp->h_aliases[0]);
+ }
+ }
+
+ /* Disable rhosts authentication if not running as root. */
+ if (original_effective_uid != 0)
+ {
+ options.rhosts_authentication = 0;
+ options.rhosts_rsa_authentication = 0;
+ }
+
+ /* If using rsh has been selected, exec it now (without trying anything
+ else). Note that we must release privileges first. */
+ if (options.use_rsh)
+ {
+ /* Restore our superuser privileges. This must be done before
+ permanently setting the uid. */
+ restore_uid();
+
+ /* Switch to the original uid permanently. */
+ permanently_set_uid(original_real_uid);
+
+ /* Execute rsh. */
+ rsh_connect(host, options.user, &command);
+ fatal("rsh_connect returned");
+ }
+
+ /* Restore our superuser privileges. */
+ restore_uid();
+
+ /* Open a connection to the remote host. This needs root privileges if
+ rhosts_{rsa_}authentication is true. */
+
+ if (!options.use_privileged_port)
+ {
+ options.rhosts_authentication = 0;
+ options.rhosts_rsa_authentication = 0;
+ }
+
+ ok = ssh_connect(host, &hostaddr, options.port, options.connection_attempts,
+ !options.rhosts_authentication &&
+ !options.rhosts_rsa_authentication,
+ original_real_uid, options.proxy_command);
+
+ /* If we successfully made the connection, load the host private key in
+ case we will need it later for combined rsa-rhosts authentication.
+ This must be done before releasing extra privileges, because the file
+ is only readable by root. */
+ if (ok)
+ {
+ host_private_key = RSA_new();
+ if (load_private_key(HOST_KEY_FILE, "", host_private_key, NULL))
+ host_private_key_loaded = 1;
+ }
+
+ /* Get rid of any extra privileges that we may have. We will no longer need
+ them. Also, extra privileges could make it very hard to read identity
+ files and other non-world-readable files from the user's home directory
+ if it happens to be on a NFS volume where root is mapped to nobody. */
+ permanently_set_uid(original_real_uid);
+
+ /* Now that we are back to our own permissions, create ~/.ssh directory
+ if it doesn\'t already exist. */
+ snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, SSH_USER_DIR);
+ if (stat(buf, &st) < 0)
+ if (mkdir(buf, 0755) < 0)
+ error("Could not create directory '%.200s'.", buf);
+
+ /* Check if the connection failed, and try "rsh" if appropriate. */
+ if (!ok)
+ {
+ if (options.port != 0)
+ log("Secure connection to %.100s on port %d refused%.100s.",
+ host, options.port,
+ options.fallback_to_rsh ? "; reverting to insecure method" : "");
+ else
+ log("Secure connection to %.100s refused%.100s.", host,
+ options.fallback_to_rsh ? "; reverting to insecure method" : "");
+
+ if (options.fallback_to_rsh)
+ {
+ rsh_connect(host, options.user, &command);
+ fatal("rsh_connect returned");
+ }
+ exit(1);
+ }
+
+ /* Expand ~ in options.identity_files. */
+ for (i = 0; i < options.num_identity_files; i++)
+ options.identity_files[i] =
+ tilde_expand_filename(options.identity_files[i], original_real_uid);
+
+ /* Expand ~ in known host file names. */
+ options.system_hostfile = tilde_expand_filename(options.system_hostfile,
+ original_real_uid);
+ options.user_hostfile = tilde_expand_filename(options.user_hostfile,
+ original_real_uid);
+
+ /* Log into the remote system. This never returns if the login fails. */
+ ssh_login(host_private_key_loaded, host_private_key,
+ host, &hostaddr, &options, original_real_uid);
+
+ /* We no longer need the host private key. Clear it now. */
+ if (host_private_key_loaded)
+ RSA_free(host_private_key); /* Destroys contents safely */
+
+ /* Close connection cleanly after attack. */
+ cipher_attack_detected = packet_disconnect;
+
+ /* If requested, fork and let ssh continue in the background. */
+ if (fork_after_authentication_flag)
+ {
+ int ret = fork();
+ if (ret == -1)
+ fatal("fork failed: %.100s", strerror(errno));
+ if (ret != 0)
+ exit(0);
+ setsid();
+ }
+
+ /* Enable compression if requested. */
+ if (options.compression)
+ {
+ debug("Requesting compression at level %d.", options.compression_level);
+
+ if (options.compression_level < 1 || options.compression_level > 9)
+ fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
+
+ /* Send the request. */
+ packet_start(SSH_CMSG_REQUEST_COMPRESSION);
+ packet_put_int(options.compression_level);
+ packet_send();
+ packet_write_wait();
+ type = packet_read(&plen);
+ if (type == SSH_SMSG_SUCCESS)
+ packet_start_compression(options.compression_level);
+ else if (type == SSH_SMSG_FAILURE)
+ log("Warning: Remote host refused compression.");
+ else
+ packet_disconnect("Protocol error waiting for compression response.");
+ }
+
+ /* Allocate a pseudo tty if appropriate. */
+ if (tty_flag)
+ {
+ debug("Requesting pty.");
+
+ /* Start the packet. */
+ packet_start(SSH_CMSG_REQUEST_PTY);
+
+ /* Store TERM in the packet. There is no limit on the length of the
+ string. */
+ cp = getenv("TERM");
+ if (!cp)
+ cp = "";
+ packet_put_string(cp, strlen(cp));
+
+ /* Store window size in the packet. */
+ if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
+ memset(&ws, 0, sizeof(ws));
+ packet_put_int(ws.ws_row);
+ packet_put_int(ws.ws_col);
+ packet_put_int(ws.ws_xpixel);
+ packet_put_int(ws.ws_ypixel);
+
+ /* Store tty modes in the packet. */
+ tty_make_modes(fileno(stdin));
+
+ /* Send the packet, and wait for it to leave. */
+ packet_send();
+ packet_write_wait();
+
+ /* Read response from the server. */
+ type = packet_read(&plen);
+ if (type == SSH_SMSG_SUCCESS)
+ interactive = 1;
+ else if (type == SSH_SMSG_FAILURE)
+ log("Warning: Remote host failed or refused to allocate a pseudo tty.");
+ else
+ packet_disconnect("Protocol error waiting for pty request response.");
+ }
+
+ /* Request X11 forwarding if enabled and DISPLAY is set. */
+ if (options.forward_x11 && getenv("DISPLAY") != NULL)
+ {
+ char line[512], proto[512], data[512];
+ FILE *f;
+ int forwarded = 0, got_data = 0, i;
+
+#ifdef XAUTH_PATH
+ /* Try to get Xauthority information for the display. */
+ snprintf(line, sizeof line, "%.100s list %.200s 2>/dev/null",
+ XAUTH_PATH, getenv("DISPLAY"));
+ f = popen(line, "r");
+ if (f && fgets(line, sizeof(line), f) &&
+ sscanf(line, "%*s %s %s", proto, data) == 2)
+ got_data = 1;
+ if (f)
+ pclose(f);
+#endif /* XAUTH_PATH */
+ /* If we didn't get authentication data, just make up some data. The
+ forwarding code will check the validity of the response anyway, and
+ substitute this data. The X11 server, however, will ignore this
+ fake data and use whatever authentication mechanisms it was using
+ otherwise for the local connection. */
+ if (!got_data)
+ {
+ u_int32_t rand = 0;
+
+ strlcpy(proto, "MIT-MAGIC-COOKIE-1", sizeof proto);
+ for (i = 0; i < 16; i++) {
+ if (i % 4 == 0)
+ rand = arc4random();
+ snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", rand & 0xff);
+ rand >>= 8;
+ }
+ }
+
+ /* Got local authentication reasonable information. Request forwarding
+ with authentication spoofing. */
+ debug("Requesting X11 forwarding with authentication spoofing.");
+ x11_request_forwarding_with_spoofing(proto, data);
+
+ /* Read response from the server. */
+ type = packet_read(&plen);
+ if (type == SSH_SMSG_SUCCESS)
+ {
+ forwarded = 1;
+ interactive = 1;
+ }
+ else if (type == SSH_SMSG_FAILURE)
+ log("Warning: Remote host denied X11 forwarding.");
+ else
+ packet_disconnect("Protocol error waiting for X11 forwarding");
+ }
+
+ /* Tell the packet module whether this is an interactive session. */
+ packet_set_interactive(interactive, options.keepalives);
+
+ /* Clear agent forwarding if we don\'t have an agent. */
+ authfd = ssh_get_authentication_socket();
+ if (authfd < 0)
+ options.forward_agent = 0;
+ else
+ ssh_close_authentication_socket(authfd);
+
+ /* Request authentication agent forwarding if appropriate. */
+ if (options.forward_agent)
+ {
+ debug("Requesting authentication agent forwarding.");
+ auth_request_forwarding();
+
+ /* Read response from the server. */
+ type = packet_read(&plen);
+ packet_integrity_check(plen, 0, type);
+ if (type != SSH_SMSG_SUCCESS)
+ log("Warning: Remote host denied authentication agent forwarding.");
+ }
+
+ /* Initiate local TCP/IP port forwardings. */
+ for (i = 0; i < options.num_local_forwards; i++)
+ {
+ debug("Connections to local port %d forwarded to remote address %.200s:%d",
+ options.local_forwards[i].port, options.local_forwards[i].host,
+ options.local_forwards[i].host_port);
+ channel_request_local_forwarding(options.local_forwards[i].port,
+ options.local_forwards[i].host,
+ options.local_forwards[i].host_port);
+ }
+
+ /* Initiate remote TCP/IP port forwardings. */
+ for (i = 0; i < options.num_remote_forwards; i++)
+ {
+ debug("Connections to remote port %d forwarded to local address %.200s:%d",
+ options.remote_forwards[i].port, options.remote_forwards[i].host,
+ options.remote_forwards[i].host_port);
+ channel_request_remote_forwarding(options.remote_forwards[i].port,
+ options.remote_forwards[i].host,
+ options.remote_forwards[i].host_port);
+ }
+
+ /* If a command was specified on the command line, execute the command now.
+ Otherwise request the server to start a shell. */
+ if (buffer_len(&command) > 0)
+ {
+ int len = buffer_len(&command);
+ if (len > 900)
+ len = 900;
+ debug("Sending command: %.*s", len, buffer_ptr(&command));
+ packet_start(SSH_CMSG_EXEC_CMD);
+ packet_put_string(buffer_ptr(&command), buffer_len(&command));
+ packet_send();
+ packet_write_wait();
+ }
+ else
+ {
+ debug("Requesting shell.");
+ packet_start(SSH_CMSG_EXEC_SHELL);
+ packet_send();
+ packet_write_wait();
+ }
+
+ /* Enter the interactive session. */
+ exit_status = client_loop(tty_flag, tty_flag ? options.escape_char : -1);
+
+ /* Close the connection to the remote host. */
+ packet_close();
+
+ /* Exit with the status returned by the program on the remote side. */
+ exit(exit_status);
+}