diff options
Diffstat (limited to 'crypto/openssh/ssh.c')
| -rw-r--r-- | crypto/openssh/ssh.c | 1021 |
1 files changed, 1021 insertions, 0 deletions
diff --git a/crypto/openssh/ssh.c b/crypto/openssh/ssh.c new file mode 100644 index 0000000..c859056 --- /dev/null +++ b/crypto/openssh/ssh.c @@ -0,0 +1,1021 @@ +/* + * Author: Tatu Ylonen <ylo@cs.hut.fi> + * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland + * All rights reserved + * 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. + * + * As far as I am concerned, the code I have written for this software + * can be used freely for any purpose. Any derived versions of this + * software must be clearly marked as such, and if the derived work is + * incompatible with the protocol description in the RFC file, it must be + * called by a name other than "ssh" or "Secure Shell". + * + * Copyright (c) 1999 Niels Provos. All rights reserved. + * + * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> + * in Canada (German citizen). + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" +RCSID("$OpenBSD: ssh.c,v 1.69 2000/10/27 07:32:19 markus Exp $"); +RCSID("$FreeBSD$"); + +#include <openssl/evp.h> +#include <openssl/dsa.h> +#include <openssl/rsa.h> + +#include "xmalloc.h" +#include "ssh.h" +#include "packet.h" +#include "buffer.h" +#include "readconf.h" +#include "uidswap.h" + +#include "ssh2.h" +#include "compat.h" +#include "channels.h" +#include "key.h" +#include "authfd.h" +#include "authfile.h" + +extern char *__progname; + +/* Flag indicating whether IPv4 or IPv6. This can be set on the command line. + Default value is AF_UNSPEC means both IPv4 and IPv6. */ +int IPv4or6 = AF_UNSPEC; + +/* Flag indicating whether debug mode is on. This can be set on the command line. */ +int debug_flag = 0; + +/* Flag indicating whether a tty should be allocated */ +int tty_flag = 0; + +/* don't exec a shell */ +int no_shell_flag = 0; +int no_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_storage 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; + +/* command to be executed */ +Buffer command; + +/* 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 Enable authentication agent forwarding.\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 Enable X11 connection forwarding.\n"); + 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, " -T Do not allocate a tty.\n"); + fprintf(stderr, " -v Verbose; display verbose debugging messages.\n"); + fprintf(stderr, " Multiple -v increases verbosity.\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, " -N Do not execute a shell or command.\n"); + fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n"); + fprintf(stderr, " -4 Use IPv4 only.\n"); + fprintf(stderr, " -6 Use IPv6 only.\n"); + fprintf(stderr, " -2 Force protocol version 2.\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; +#ifndef _PATH_RSH +#define _PATH_RSH "/usr/bin/rsh" +#endif + args[i++] = _PATH_RSH; + /* host may have to come after user on some systems */ + args[i++] = host; + 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); +} + +int ssh_session(void); +int ssh_session2(void); + +/* + * Main program for the ssh client. + */ +int +main(int ac, char **av) +{ + int i, opt, optind, exit_status, ok; + u_short fwd_port, fwd_host_port; + char *optarg, *cp, buf[256]; + struct stat st; + struct passwd *pw, pwcopy; + int dummy; + uid_t original_effective_uid; + + /* + * 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") && strcmp(cp, "ssh") && strcmp(cp, "rlogin") && + strcmp(cp, "slogin") && strcmp(cp, "remsh")) + host = cp; + + for (optind = 1; optind < ac; optind++) { + if (av[optind][0] != '-') { + if (host) + break; + if ((cp = strchr(av[optind], '@'))) { + if(cp == av[optind]) + usage(); + 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 '2': + options.protocol = SSH_PROTO_2; + break; + case '4': + IPv4or6 = AF_INET; + break; + case '6': + IPv4or6 = AF_INET6; + break; + 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; + case 'A': + options.forward_agent = 1; + break; +#ifdef AFS + case 'k': + options.krb4_tgt_passing = 0; + options.krb5_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': + if (0 == debug_flag) { + debug_flag = 1; + options.log_level = SYSLOG_LEVEL_DEBUG1; + } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) { + options.log_level++; + break; + } else { + fatal("Too high debugging level.\n"); + } + /* fallthrough */ + case 'V': + fprintf(stderr, "SSH Version %s, protocol versions %d.%d/%d.%d.\n", + SSH_VERSION, + PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1, + PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2); + fprintf(stderr, "Compiled with SSL (0x%8.8lx).\n", SSLeay()); + if (opt == 'V') + exit(0); + break; + case 'q': + options.log_level = SYSLOG_LEVEL_QUIET; + 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': + if (ciphers_valid(optarg)) { + /* SSH2 only */ + options.ciphers = xstrdup(optarg); + options.cipher = SSH_CIPHER_ILLEGAL; + } else { + /* SSH1 only */ + Cipher *c = cipher_by_name(optarg); + if (c == NULL || c->number < 0) { + fprintf(stderr, "Unknown cipher type '%s'\n", optarg); + exit(1); + } + options.cipher = c->number; + } + break; + case 'p': + options.port = atoi(optarg); + break; + case 'l': + options.user = optarg; + break; + case 'R': + if (sscanf(optarg, "%hu/%255[^/]/%hu", &fwd_port, buf, + &fwd_host_port) != 3 && + sscanf(optarg, "%hu:%255[^:]:%hu", &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, "%hu/%255[^/]/%hu", &fwd_port, buf, + &fwd_host_port) != 3 && + sscanf(optarg, "%hu:%255[^:]:%hu", &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 'N': + no_shell_flag = 1; + no_tty_flag = 1; + break; + case 'T': + no_tty_flag = 1; + break; + case 'o': + dummy = 1; + if (process_config_line(&options, host ? host : "", optarg, + "command-line", 0, &dummy) != 0) + exit(1); + break; + default: + usage(); + } + } + + /* Check that we got a host name. */ + if (!host) + usage(); + + SSLeay_add_all_algorithms(); + + /* 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 && !no_shell_flag) + 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; + } + /* force */ + if (no_tty_flag) + 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); + pwcopy.pw_class = xstrdup(pw->pw_class); + pwcopy.pw_expire = pw->pw_expire; + pwcopy.pw_change = pw->pw_change; + pw = &pwcopy; + + /* Initialize "log" output. Since we are the client all output + actually goes to the terminal. */ + log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 0); + + /* 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); + + /* reinit */ + log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 0); + + /* check if RSA support exists */ + if ((options.protocol & SSH_PROTO_1) && + rsa_alive() == 0) { + log("%s: no RSA support in libssl and libcrypto. See ssl(8).", + __progname); + log("Disabling protocol version 1"); + options.protocol &= ~ (SSH_PROTO_1|SSH_PROTO_1_PREFERRED); + } + if (! options.protocol & (SSH_PROTO_1|SSH_PROTO_2)) { + fprintf(stderr, "%s: No protocol version available.\n", + __progname); + exit(1); + } + + if (options.user == NULL) + options.user = xstrdup(pw->pw_name); + + if (options.hostname != NULL) + host = options.hostname; + + /* Disable rhosts authentication if not running as root. */ + if (original_effective_uid != 0 || !options.use_privileged_port) { + 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 enabled. + */ + + 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 && (options.protocol & SSH_PROTO_1)) { + Key k; + host_private_key = RSA_new(); + k.type = KEY_RSA; + k.rsa = host_private_key; + if (load_private_key(HOST_KEY_FILE, "", &k, 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. + */ + + /* + * Note that some legacy systems need to postpone the following call + * to permanently_set_uid() until the private hostkey is destroyed + * with RSA_free(). Otherwise the calling user could ptrace() the + * process, read the private hostkey and impersonate the host. + * OpenBSD does not allow ptracing of setuid processes. + */ + 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, 0700) < 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 %hu 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. */ + /* XXX mem-leaks */ + for (i = 0; i < options.num_identity_files; i++) + options.identity_files[i] = + tilde_expand_filename(options.identity_files[i], original_real_uid); + for (i = 0; i < options.num_identity_files2; i++) + options.identity_files2[i] = + tilde_expand_filename(options.identity_files2[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); + options.system_hostfile2 = tilde_expand_filename(options.system_hostfile2, + original_real_uid); + options.user_hostfile2 = tilde_expand_filename(options.user_hostfile2, + 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, (struct sockaddr *)&hostaddr, 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 */ + + exit_status = compat20 ? ssh_session2() : ssh_session(); + packet_close(); + return exit_status; +} + +void +x11_get_proto(char *proto, int proto_len, char *data, int data_len) +{ + char line[512]; + FILE *f; + int got_data = 0, i; + + if (options.xauth_location) { + /* Try to get Xauthority information for the display. */ + snprintf(line, sizeof line, "%.100s list %.200s 2>/dev/null", + options.xauth_location, 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); + } + /* + * 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", proto_len); + for (i = 0; i < 16; i++) { + if (i % 4 == 0) + rand = arc4random(); + snprintf(data + 2 * i, data_len - 2 * i, "%02x", rand & 0xff); + rand >>= 8; + } + } +} + +int +ssh_session(void) +{ + int type; + int i; + int plen; + int interactive = 0; + int have_tty = 0; + struct winsize ws; + int authfd; + char *cp; + + /* 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; + have_tty = 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 proto[512], data[512]; + /* Get reasonable local authentication information. */ + x11_get_proto(proto, sizeof proto, data, sizeof data); + /* Request forwarding with authentication spoofing. */ + debug("Requesting X11 forwarding with authentication spoofing."); + x11_request_forwarding_with_spoofing(0, proto, data); + + /* 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 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, + options.gateway_ports); + } + + /* 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 requested, let ssh continue in the background. */ + if (fork_after_authentication_flag) + if (daemon(1, 1) < 0) + fatal("daemon() failed: %.200s", strerror(errno)); + + /* + * 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. */ + return client_loop(have_tty, tty_flag ? options.escape_char : -1, 0); +} + +void +init_local_fwd(void) +{ + int i; + /* 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, + options.gateway_ports); + } +} + +extern void client_set_session_ident(int id); + +void +client_init(int id, void *arg) +{ + int len; + debug("client_init id %d arg %d", id, (int)arg); + + if (no_shell_flag) + goto done; + + if (tty_flag) { + struct winsize ws; + char *cp; + cp = getenv("TERM"); + if (!cp) + cp = ""; + /* Store window size in the packet. */ + if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) + memset(&ws, 0, sizeof(ws)); + + channel_request_start(id, "pty-req", 0); + packet_put_cstring(cp); + packet_put_int(ws.ws_col); + packet_put_int(ws.ws_row); + packet_put_int(ws.ws_xpixel); + packet_put_int(ws.ws_ypixel); + packet_put_cstring(""); /* XXX: encode terminal modes */ + packet_send(); + /* XXX wait for reply */ + } + if (options.forward_x11 && + getenv("DISPLAY") != NULL) { + char proto[512], data[512]; + /* Get reasonable local authentication information. */ + x11_get_proto(proto, sizeof proto, data, sizeof data); + /* Request forwarding with authentication spoofing. */ + debug("Requesting X11 forwarding with authentication spoofing."); + x11_request_forwarding_with_spoofing(id, proto, data); + /* XXX wait for reply */ + } + + len = buffer_len(&command); + if (len > 0) { + if (len > 900) + len = 900; + debug("Sending command: %.*s", len, buffer_ptr(&command)); + channel_request_start(id, "exec", 0); + packet_put_string(buffer_ptr(&command), len); + packet_send(); + } else { + channel_request(id, "shell", 0); + } + /* channel_callback(id, SSH2_MSG_OPEN_CONFIGMATION, client_init, 0); */ +done: + /* register different callback, etc. XXX */ + client_set_session_ident(id); +} + +int +ssh_session2(void) +{ + int window, packetmax, id; + int in, out, err; + + if (stdin_null_flag) { + in = open("/dev/null", O_RDONLY); + } else { + in = dup(STDIN_FILENO); + } + out = dup(STDOUT_FILENO); + err = dup(STDERR_FILENO); + + if (in < 0 || out < 0 || err < 0) + fatal("dup() in/out/err failed"); + + /* enable nonblocking unless tty */ + if (!isatty(in)) + set_nonblock(in); + if (!isatty(out)) + set_nonblock(out); + if (!isatty(err)) + set_nonblock(err); + + /* should be pre-session */ + init_local_fwd(); + + /* If requested, let ssh continue in the background. */ + if (fork_after_authentication_flag) + if (daemon(1, 1) < 0) + fatal("daemon() failed: %.200s", strerror(errno)); + + window = CHAN_SES_WINDOW_DEFAULT; + packetmax = CHAN_SES_PACKET_DEFAULT; + if (!tty_flag) { + window *= 2; + packetmax *=2; + } + id = channel_new( + "session", SSH_CHANNEL_OPENING, in, out, err, + window, packetmax, CHAN_EXTENDED_WRITE, + xstrdup("client-session"), /*nonblock*/0); + + channel_open(id); + channel_register_callback(id, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, client_init, (void *)0); + + return client_loop(tty_flag, tty_flag ? options.escape_char : -1, id); +} |
