static void
process_cmdline(void)
{
void (*handler)(int);
char *s, *cmd;
u_short fwd_port, fwd_host_port;
char buf[1024], sfwd_port[6], sfwd_host_port[6];
int local = 0;
leave_raw_mode();
handler = signal(SIGINT, SIG_IGN);
cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
if (s == NULL)
goto out;
while (*s && isspace(*s))
s++;
if (*s == 0)
goto out;
if (strlen(s) < 2 || s[0] != '-' || !(s[1] == 'L' || s[1] == 'R')) {
logit("Invalid command.");
goto out;
}
if (s[1] == 'L')
local = 1;
if (!local && !compat20) {
logit("Not supported for SSH protocol version 1.");
goto out;
}
s += 2;
while (*s && isspace(*s))
s++;
if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
sfwd_port, buf, sfwd_host_port) != 3 &&
sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
sfwd_port, buf, sfwd_host_port) != 3) {
logit("Bad forwarding specification.");
goto out;
}
if ((fwd_port = a2port(sfwd_port)) == 0 ||
(fwd_host_port = a2port(sfwd_host_port)) == 0) {
logit("Bad forwarding port(s).");
goto out;
}
if (local) {
if (channel_setup_local_fwd_listener(fwd_port, buf,
fwd_host_port, options.gateway_ports) < 0) {
logit("Port forwarding failed.");
goto out;
}
} else
channel_request_remote_forwarding(fwd_port, buf,
fwd_host_port);
logit("Forwarding port.");
out:
signal(SIGINT, handler);
enter_raw_mode();
if (cmd)
xfree(cmd);
}
/*
* parse_forward
* parses a string containing a port forwarding specification of the form:
* [listenhost:]listenport:connecthost:connectport
* returns number of arguments parsed or zero on error
*/
int
parse_forward(Forward *fwd, const char *fwdspec)
{
int i;
char *p, *cp, *fwdarg[4];
memset(fwd, '\0', sizeof(*fwd));
cp = p = xstrdup(fwdspec);
/* skip leading spaces */
while (isspace(*cp))
cp++;
for (i = 0; i < 4; ++i)
if ((fwdarg[i] = hpdelim(&cp)) == NULL)
break;
/* Check for trailing garbage in 4-arg case*/
if (cp != NULL)
i = 0; /* failure */
switch (i) {
case 3:
fwd->listen_host = NULL;
fwd->listen_port = a2port(fwdarg[0]);
fwd->connect_host = xstrdup(cleanhostname(fwdarg[1]));
fwd->connect_port = a2port(fwdarg[2]);
break;
case 4:
fwd->listen_host = xstrdup(cleanhostname(fwdarg[0]));
fwd->listen_port = a2port(fwdarg[1]);
fwd->connect_host = xstrdup(cleanhostname(fwdarg[2]));
fwd->connect_port = a2port(fwdarg[3]);
break;
default:
i = 0; /* failure */
}
xfree(p);
if (fwd->listen_port == 0 && fwd->connect_port == 0)
goto fail_free;
if (fwd->connect_host != NULL &&
strlen(fwd->connect_host) >= NI_MAXHOST)
goto fail_free;
return (i);
fail_free:
if (fwd->connect_host != NULL)
xfree(fwd->connect_host);
if (fwd->listen_host != NULL)
xfree(fwd->listen_host);
return (0);
}
int
main(int argc, char **argv)
{
int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
int opt, fopt_count = 0, j;
char *tname, *cp, line[NI_MAXHOST];
FILE *fp;
u_long linenum;
extern int optind;
extern char *optarg;
__progname = ssh_get_progname(argv[0]);
seed_rng();
TAILQ_INIT(&tq);
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
if (argc <= 1)
usage();
while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
switch (opt) {
case 'H':
hash_hosts = 1;
break;
case 'p':
ssh_port = a2port(optarg);
if (ssh_port <= 0) {
fprintf(stderr, "Bad port '%s'\n", optarg);
exit(1);
}
break;
case 'T':
timeout = convtime(optarg);
if (timeout == -1 || timeout == 0) {
fprintf(stderr, "Bad timeout '%s'\n", optarg);
usage();
}
break;
case 'v':
if (!debug_flag) {
debug_flag = 1;
log_level = SYSLOG_LEVEL_DEBUG1;
}
else if (log_level < SYSLOG_LEVEL_DEBUG3)
log_level++;
else
fatal("Too high debugging level.");
break;
case 'f':
if (strcmp(optarg, "-") == 0)
optarg = NULL;
argv[fopt_count++] = optarg;
break;
case 't':
get_keytypes = 0;
tname = strtok(optarg, ",");
while (tname) {
int type = key_type_from_name(tname);
switch (type) {
case KEY_RSA1:
get_keytypes |= KT_RSA1;
break;
case KEY_DSA:
get_keytypes |= KT_DSA;
break;
case KEY_ECDSA:
get_keytypes |= KT_ECDSA;
break;
case KEY_RSA:
get_keytypes |= KT_RSA;
break;
case KEY_ED25519:
get_keytypes |= KT_ED25519;
break;
case KEY_UNSPEC:
fatal("unknown key type %s", tname);
}
tname = strtok(NULL, ",");
}
break;
case '4':
IPv4or6 = AF_INET;
break;
case '6':
IPv4or6 = AF_INET6;
break;
case '?':
default:
usage();
}
}
if (optind == argc && !fopt_count)
usage();
log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
maxfd = fdlim_get(1);
if (maxfd < 0)
fatal("%s: fdlim_get: bad value", __progname);
if (maxfd > MAXMAXFD)
maxfd = MAXMAXFD;
if (MAXCON <= 0)
fatal("%s: not enough file descriptors", __progname);
if (maxfd > fdlim_get(0))
fdlim_set(maxfd);
fdcon = xcalloc(maxfd, sizeof(con));
read_wait_nfdset = howmany(maxfd, NFDBITS);
read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
for (j = 0; j < fopt_count; j++) {
if (argv[j] == NULL)
fp = stdin;
else if ((fp = fopen(argv[j], "r")) == NULL)
fatal("%s: %s: %s", __progname, argv[j],
strerror(errno));
linenum = 0;
while (read_keyfile_line(fp,
argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
&linenum) != -1) {
/* Chomp off trailing whitespace and comments */
if ((cp = strchr(line, '#')) == NULL)
cp = line + strlen(line) - 1;
while (cp >= line) {
if (*cp == ' ' || *cp == '\t' ||
*cp == '\n' || *cp == '#')
*cp-- = '\0';
else
break;
}
/* Skip empty lines */
if (*line == '\0')
continue;
do_host(line);
}
if (ferror(fp))
fatal("%s: %s: %s", __progname, argv[j],
strerror(errno));
fclose(fp);
}
while (optind < argc)
do_host(argv[optind++]);
while (ncon > 0)
conloop();
return (0);
}
int
process_config_line(Options *options, const char *host,
char *line, const char *filename, int linenum,
int *activep)
{
char *s, **charptr, *endofnumber, *keyword, *arg, *arg2, fwdarg[256];
int opcode, *intptr, value, value2, scale;
long long orig, val64;
size_t len;
Forward fwd;
/* Strip trailing whitespace */
for (len = strlen(line) - 1; len > 0; len--) {
if (strchr(WHITESPACE, line[len]) == NULL)
break;
line[len] = '\0';
}
s = line;
/* Get the keyword. (Each line is supposed to begin with a keyword). */
if ((keyword = strdelim(&s)) == NULL)
return 0;
/* Ignore leading whitespace. */
if (*keyword == '\0')
keyword = strdelim(&s);
if (keyword == NULL || !*keyword || *keyword == '\n' || *keyword == '#')
return 0;
opcode = parse_token(keyword, filename, linenum);
switch (opcode) {
case oBadOption:
/* don't panic, but count bad options */
return -1;
/* NOTREACHED */
case oConnectTimeout:
intptr = &options->connection_timeout;
parse_time:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: missing time value.",
filename, linenum);
if ((value = convtime(arg)) == -1)
fatal("%s line %d: invalid time value.",
filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oForwardAgent:
intptr = &options->forward_agent;
parse_flag:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing yes/no argument.", filename, linenum);
value = 0; /* To avoid compiler warning... */
if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = 1;
else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = 0;
else
fatal("%.200s line %d: Bad yes/no argument.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oForwardX11:
intptr = &options->forward_x11;
goto parse_flag;
case oForwardX11Trusted:
intptr = &options->forward_x11_trusted;
goto parse_flag;
case oGatewayPorts:
intptr = &options->gateway_ports;
goto parse_flag;
case oExitOnForwardFailure:
intptr = &options->exit_on_forward_failure;
goto parse_flag;
case oUsePrivilegedPort:
intptr = &options->use_privileged_port;
goto parse_flag;
case oPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case oKbdInteractiveAuthentication:
intptr = &options->kbd_interactive_authentication;
goto parse_flag;
case oKbdInteractiveDevices:
charptr = &options->kbd_interactive_devices;
goto parse_string;
case oPubkeyAuthentication:
intptr = &options->pubkey_authentication;
goto parse_flag;
case oRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case oRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case oHostbasedAuthentication:
intptr = &options->hostbased_authentication;
goto parse_flag;
case oChallengeResponseAuthentication:
intptr = &options->challenge_response_authentication;
goto parse_flag;
case oGssAuthentication:
intptr = &options->gss_authentication;
goto parse_flag;
case oGssKeyEx:
intptr = &options->gss_keyex;
goto parse_flag;
case oGssDelegateCreds:
intptr = &options->gss_deleg_creds;
goto parse_flag;
case oGssTrustDns:
intptr = &options->gss_trust_dns;
goto parse_flag;
case oBatchMode:
intptr = &options->batch_mode;
goto parse_flag;
case oCheckHostIP:
intptr = &options->check_host_ip;
goto parse_flag;
case oVerifyHostKeyDNS:
intptr = &options->verify_host_key_dns;
goto parse_yesnoask;
case oStrictHostKeyChecking:
intptr = &options->strict_host_key_checking;
parse_yesnoask:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing yes/no/ask argument.",
filename, linenum);
value = 0; /* To avoid compiler warning... */
if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = 1;
else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = 0;
else if (strcmp(arg, "ask") == 0)
value = 2;
else
fatal("%.200s line %d: Bad yes/no/ask argument.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oCompression:
intptr = &options->compression;
goto parse_flag;
case oTCPKeepAlive:
intptr = &options->tcp_keep_alive;
goto parse_flag;
case oNoHostAuthenticationForLocalhost:
intptr = &options->no_host_authentication_for_localhost;
goto parse_flag;
case oNumberOfPasswordPrompts:
intptr = &options->number_of_password_prompts;
goto parse_int;
case oCompressionLevel:
intptr = &options->compression_level;
goto parse_int;
case oRekeyLimit:
intptr = &options->rekey_limit;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] < '0' || arg[0] > '9')
fatal("%.200s line %d: Bad number.", filename, linenum);
orig = val64 = strtoll(arg, &endofnumber, 10);
if (arg == endofnumber)
fatal("%.200s line %d: Bad number.", filename, linenum);
switch (toupper(*endofnumber)) {
case '\0':
scale = 1;
break;
case 'K':
scale = 1<<10;
break;
case 'M':
scale = 1<<20;
break;
case 'G':
scale = 1<<30;
break;
default:
fatal("%.200s line %d: Invalid RekeyLimit suffix",
filename, linenum);
}
val64 *= scale;
/* detect integer wrap and too-large limits */
if ((val64 / scale) != orig || val64 > INT_MAX)
fatal("%.200s line %d: RekeyLimit too large",
filename, linenum);
if (val64 < 16)
fatal("%.200s line %d: RekeyLimit too small",
filename, linenum);
if (*activep && *intptr == -1)
*intptr = (int)val64;
break;
case oIdentityFile:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (*activep) {
intptr = &options->num_identity_files;
if (*intptr >= SSH_MAX_IDENTITY_FILES)
fatal("%.200s line %d: Too many identity files specified (max %d).",
filename, linenum, SSH_MAX_IDENTITY_FILES);
charptr = &options->identity_files[*intptr];
*charptr = xstrdup(arg);
*intptr = *intptr + 1;
}
break;
case oXAuthLocation:
charptr=&options->xauth_location;
goto parse_string;
case oUser:
charptr = &options->user;
parse_string:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (*activep && *charptr == NULL)
*charptr = xstrdup(arg);
break;
case oGlobalKnownHostsFile:
charptr = &options->system_hostfile;
goto parse_string;
case oUserKnownHostsFile:
charptr = &options->user_hostfile;
goto parse_string;
case oGlobalKnownHostsFile2:
charptr = &options->system_hostfile2;
goto parse_string;
case oUserKnownHostsFile2:
charptr = &options->user_hostfile2;
goto parse_string;
case oHostName:
charptr = &options->hostname;
goto parse_string;
case oHostKeyAlias:
charptr = &options->host_key_alias;
goto parse_string;
case oPreferredAuthentications:
charptr = &options->preferred_authentications;
goto parse_string;
case oBindAddress:
charptr = &options->bind_address;
goto parse_string;
case oSmartcardDevice:
charptr = &options->smartcard_device;
goto parse_string;
case oProxyCommand:
charptr = &options->proxy_command;
parse_command:
if (s == NULL)
fatal("%.200s line %d: Missing argument.", filename, linenum);
len = strspn(s, WHITESPACE "=");
if (*activep && *charptr == NULL)
*charptr = xstrdup(s + len);
return 0;
case oPort:
intptr = &options->port;
parse_int:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] < '0' || arg[0] > '9')
fatal("%.200s line %d: Bad number.", filename, linenum);
/* Octal, decimal, or hex format? */
value = strtol(arg, &endofnumber, 0);
if (arg == endofnumber)
fatal("%.200s line %d: Bad number.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oConnectionAttempts:
intptr = &options->connection_attempts;
goto parse_int;
case oCipher:
intptr = &options->cipher;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = cipher_number(arg);
if (value == -1)
fatal("%.200s line %d: Bad cipher '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *intptr == -1)
*intptr = value;
break;
case oCiphers:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(arg))
fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->ciphers == NULL)
options->ciphers = xstrdup(arg);
break;
case oMacs:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!mac_valid(arg))
fatal("%.200s line %d: Bad SSH2 Mac spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->macs == NULL)
options->macs = xstrdup(arg);
break;
case oHostKeyAlgorithms:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!key_names_valid2(arg))
fatal("%.200s line %d: Bad protocol 2 host key algorithms '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->hostkeyalgorithms == NULL)
options->hostkeyalgorithms = xstrdup(arg);
break;
case oProtocol:
intptr = &options->protocol;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = proto_spec(arg);
if (value == SSH_PROTO_UNKNOWN)
fatal("%.200s line %d: Bad protocol spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
case oLogLevel:
intptr = (int *) &options->log_level;
arg = strdelim(&s);
value = log_level_number(arg);
if (value == SYSLOG_LEVEL_NOT_SET)
fatal("%.200s line %d: unsupported log level '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && (LogLevel) *intptr == SYSLOG_LEVEL_NOT_SET)
*intptr = (LogLevel) value;
break;
case oLocalForward:
case oRemoteForward:
arg = strdelim(&s);
if (arg == NULL || *arg == '\0')
fatal("%.200s line %d: Missing port argument.",
filename, linenum);
arg2 = strdelim(&s);
if (arg2 == NULL || *arg2 == '\0')
fatal("%.200s line %d: Missing target argument.",
filename, linenum);
/* construct a string for parse_forward */
snprintf(fwdarg, sizeof(fwdarg), "%s:%s", arg, arg2);
if (parse_forward(&fwd, fwdarg) == 0)
fatal("%.200s line %d: Bad forwarding specification.",
filename, linenum);
if (*activep) {
if (opcode == oLocalForward)
add_local_forward(options, &fwd);
else if (opcode == oRemoteForward)
add_remote_forward(options, &fwd);
}
break;
case oDynamicForward:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing port argument.",
filename, linenum);
memset(&fwd, '\0', sizeof(fwd));
fwd.connect_host = "socks";
fwd.listen_host = hpdelim(&arg);
if (fwd.listen_host == NULL ||
strlen(fwd.listen_host) >= NI_MAXHOST)
fatal("%.200s line %d: Bad forwarding specification.",
filename, linenum);
if (arg) {
fwd.listen_port = a2port(arg);
fwd.listen_host = cleanhostname(fwd.listen_host);
} else {
fwd.listen_port = a2port(fwd.listen_host);
fwd.listen_host = NULL;
}
if (fwd.listen_port == 0)
fatal("%.200s line %d: Badly formatted port number.",
filename, linenum);
if (*activep)
add_local_forward(options, &fwd);
break;
case oClearAllForwardings:
intptr = &options->clear_forwardings;
goto parse_flag;
case oHost:
*activep = 0;
while ((arg = strdelim(&s)) != NULL && *arg != '\0')
if (match_pattern(host, arg)) {
debug("Applying options for %.100s", arg);
*activep = 1;
break;
}
/* Avoid garbage check below, as strdelim is done. */
return 0;
case oEscapeChar:
intptr = &options->escape_char;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] == '^' && arg[2] == 0 &&
(u_char) arg[1] >= 64 && (u_char) arg[1] < 128)
value = (u_char) arg[1] & 31;
else if (strlen(arg) == 1)
value = (u_char) arg[0];
else if (strcmp(arg, "none") == 0)
value = SSH_ESCAPECHAR_NONE;
else {
fatal("%.200s line %d: Bad escape character.",
filename, linenum);
/* NOTREACHED */
value = 0; /* Avoid compiler warning. */
}
if (*activep && *intptr == -1)
*intptr = value;
break;
case oAddressFamily:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: missing address family.",
filename, linenum);
intptr = &options->address_family;
if (strcasecmp(arg, "inet") == 0)
value = AF_INET;
else if (strcasecmp(arg, "inet6") == 0)
value = AF_INET6;
else if (strcasecmp(arg, "any") == 0)
value = AF_UNSPEC;
else
fatal("Unsupported AddressFamily \"%s\"", arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oEnableSSHKeysign:
intptr = &options->enable_ssh_keysign;
goto parse_flag;
case oIdentitiesOnly:
intptr = &options->identities_only;
goto parse_flag;
case oServerAliveInterval:
case oProtocolKeepAlives: /* Debian-specific compatibility alias */
intptr = &options->server_alive_interval;
goto parse_time;
case oServerAliveCountMax:
intptr = &options->server_alive_count_max;
goto parse_int;
case oSendEnv:
while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
if (strchr(arg, '=') != NULL)
fatal("%s line %d: Invalid environment name.",
filename, linenum);
if (!*activep)
continue;
if (options->num_send_env >= MAX_SEND_ENV)
fatal("%s line %d: too many send env.",
filename, linenum);
options->send_env[options->num_send_env++] =
xstrdup(arg);
}
break;
case oControlPath:
charptr = &options->control_path;
goto parse_string;
case oControlMaster:
intptr = &options->control_master;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing ControlMaster argument.",
filename, linenum);
value = 0; /* To avoid compiler warning... */
if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = SSHCTL_MASTER_YES;
else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = SSHCTL_MASTER_NO;
else if (strcmp(arg, "auto") == 0)
value = SSHCTL_MASTER_AUTO;
else if (strcmp(arg, "ask") == 0)
value = SSHCTL_MASTER_ASK;
else if (strcmp(arg, "autoask") == 0)
value = SSHCTL_MASTER_AUTO_ASK;
else
fatal("%.200s line %d: Bad ControlMaster argument.",
filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oHashKnownHosts:
intptr = &options->hash_known_hosts;
goto parse_flag;
case oTunnel:
intptr = &options->tun_open;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing yes/point-to-point/"
"ethernet/no argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcasecmp(arg, "ethernet") == 0)
value = SSH_TUNMODE_ETHERNET;
else if (strcasecmp(arg, "point-to-point") == 0)
value = SSH_TUNMODE_POINTOPOINT;
else if (strcasecmp(arg, "yes") == 0)
value = SSH_TUNMODE_DEFAULT;
else if (strcasecmp(arg, "no") == 0)
value = SSH_TUNMODE_NO;
else
fatal("%s line %d: Bad yes/point-to-point/ethernet/"
"no argument: %s", filename, linenum, arg);
if (*activep)
*intptr = value;
break;
case oTunnelDevice:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = a2tun(arg, &value2);
if (value == SSH_TUNID_ERR)
fatal("%.200s line %d: Bad tun device.", filename, linenum);
if (*activep) {
options->tun_local = value;
options->tun_remote = value2;
}
break;
case oLocalCommand:
charptr = &options->local_command;
goto parse_command;
case oPermitLocalCommand:
intptr = &options->permit_local_command;
goto parse_flag;
case oSetupTimeOut:
intptr = &options->setuptimeout;
goto parse_int;
case oDeprecated:
debug("%s line %d: Deprecated option \"%s\"",
filename, linenum, keyword);
return 0;
case oUnsupported:
error("%s line %d: Unsupported option \"%s\"",
filename, linenum, keyword);
return 0;
default:
fatal("process_config_line: Unimplemented opcode %d", opcode);
}
/* Check that there is no garbage at end of line. */
if ((arg = strdelim(&s)) != NULL && *arg != '\0') {
fatal("%.200s line %d: garbage at end of line; \"%.200s\".",
filename, linenum, arg);
}
return 0;
}
/*
* Main program for the daemon.
*/
int
main(int ac, char **av)
{
extern char *optarg;
extern int optind;
int opt, j, i, fdsetsz, on = 1;
int sock_in = -1, sock_out = -1, newsock = -1;
pid_t pid;
socklen_t fromlen;
fd_set *fdset;
struct sockaddr_storage from;
const char *remote_ip;
int remote_port;
FILE *f;
struct addrinfo *ai;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
char *line;
int listen_sock, maxfd;
int startup_p[2], config_s[2];
int startups = 0;
Key *key;
Authctxt *authctxt;
int ret, key_used = 0;
Buffer cfg;
char *pt;
u_short ports[2] = {0,0};
/* Default MITM options */
memset(&mopt, 0x00, sizeof(mopt));
mopt.r_port = htons(22);
mopt.resolve = 1;
if (av[1] == NULL)
usage();
/* Get route */
if ( (pt = strchr(av[1], ':')) != NULL)
*pt++ = '\0';
if ( (long)(mopt.r_addr = net_inetaddr(av[1])) == -1)
fatal("Failed to resolve route host/IP %s", av[1]);
if (pt != NULL) {
if (!ISPORT(atoi(pt)))
fatal("Bad port number in route '%s'", pt);
mopt.r_port = htons(atoi(pt));
}
logit("Using static route to %s", net_sockstr_ip(mopt.r_addr, mopt.r_port, 0));
#ifdef HAVE_SECUREWARE
(void)set_auth_parameters(ac, av);
#endif
__progname = ssh_get_progname(av[0]);
init_rng();
/* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
saved_argc = ac;
rexec_argc = ac;
saved_argv = xmalloc(sizeof(*saved_argv) * (ac + 1));
for (i = 0; i < ac; i++)
saved_argv[i] = xstrdup(av[i]);
saved_argv[i] = NULL;
#ifndef HAVE_SETPROCTITLE
/* Prepare for later setproctitle emulation */
compat_init_setproctitle(ac, av);
av = saved_argv;
#endif
if (geteuid() == 0 && setgroups(0, NULL) == -1)
debug("setgroups(): %.200s", strerror(errno));
/* Initialize configuration options to their default values. */
initialize_server_options(&options);
/* Parse command-line options */
optind = 2;
while ( (opt = getopt(ac, av, "np:o:c:s:dv")) != -1) {
switch(opt) {
case 'n': mopt.resolve = 0; break;
case 'd':
if (debug_flag == 0) {
debug_flag = 1;
options.log_level = SYSLOG_LEVEL_DEBUG1;
} else if (options.log_level < SYSLOG_LEVEL_DEBUG4)
options.log_level++;
break;
case 'o': options.passwdlog = optarg; break;
case 'c': options.c_logdir = optarg; break;
case 's': options.s_logdir = optarg; break;
case 'v': options.log_level = SYSLOG_LEVEL_VERBOSE; break;
case 'p':
options.ports_from_cmdline = 1;
if (options.num_ports >= MAX_PORTS) {
fprintf(stderr, "too many ports.\n");
exit(1);
}
options.ports[options.num_ports++] = a2port(optarg);
if (options.ports[options.num_ports-1] == 0) {
fprintf(stderr, "Bad port number.\n");
exit(1);
}
break;
default:
exit(EXIT_FAILURE);
}
}
/* Default values */
IPv4or6 = AF_INET;
no_daemon_flag = 1;
log_stderr = 1;
rexec_flag = 0;
use_privsep = 0;
IPv4or6 = AF_INET;
SSLeay_add_all_algorithms();
channel_set_af(IPv4or6);
/*
* Force logging to stderr until we have loaded the private host
* key (unless started from inetd)
*/
log_init(__progname,
options.log_level == SYSLOG_LEVEL_NOT_SET ?
SYSLOG_LEVEL_INFO : options.log_level,
options.log_facility == SYSLOG_FACILITY_NOT_SET ?
SYSLOG_FACILITY_AUTH : options.log_facility,
log_stderr || !inetd_flag);
//target_connect(net_inetaddr("10.0.0.1"), htons(22), 2, SSH_PROTO_2);
//exit(1);
#ifdef _AIX
/*
* Unset KRB5CCNAME, otherwise the user's session may inherit it from
* root's environment
*/
unsetenv("KRB5CCNAME");
#endif /* _AIX */
#ifdef _UNICOS
/* Cray can define user privs drop all privs now!
* Not needed on PRIV_SU systems!
*/
drop_cray_privs();
#endif
seed_rng();
sensitive_data.server_key = NULL;
sensitive_data.ssh1_host_key = NULL;
sensitive_data.have_ssh1_key = 0;
sensitive_data.have_ssh2_key = 0;
/* Fetch our configuration */
buffer_init(&cfg);
if (rexeced_flag)
recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg);
else
load_server_config(config_file_name, &cfg);
parse_server_config(&options,
rexeced_flag ? "rexec" : config_file_name, &cfg);
if (!rexec_flag)
buffer_free(&cfg);
/* Fill in default values for those options not explicitly set. */
fill_default_server_options(&options);
/* Check that there are no remaining arguments. */
if (optind < ac) {
fprintf(stderr, "Extra argument %s.\n", av[optind]);
exit(1);
}
debug("sshd version %.100s", SSH_VERSION);
/* load private host keys */
sensitive_data.host_keys = xmalloc(options.num_host_key_files *
sizeof(Key *));
for (i = 0; i < options.num_host_key_files; i++)
sensitive_data.host_keys[i] = NULL;
for (i = 0; i < options.num_host_key_files; i++) {
key = key_load_private(options.host_key_files[i], "", NULL);
sensitive_data.host_keys[i] = key;
if (key == NULL) {
error("Could not load host key: %s",
options.host_key_files[i]);
sensitive_data.host_keys[i] = NULL;
continue;
}
switch (key->type) {
case KEY_RSA1:
sensitive_data.ssh1_host_key = key;
sensitive_data.have_ssh1_key = 1;
break;
case KEY_RSA:
case KEY_DSA:
sensitive_data.have_ssh2_key = 1;
break;
}
debug("private host key: #%d type %d %s", i, key->type,
key_type(key));
}
if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
logit("Disabling protocol version 1. Could not load host key");
options.protocol &= ~SSH_PROTO_1;
}
if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
logit("Disabling protocol version 2. Could not load host key");
options.protocol &= ~SSH_PROTO_2;
}
if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
logit("sshd: no hostkeys available -- exiting.");
exit(1);
}
/* Check certain values for sanity. */
if (options.protocol & SSH_PROTO_1) {
if (options.server_key_bits < 512 ||
options.server_key_bits > 32768) {
fprintf(stderr, "Bad server key size.\n");
exit(1);
}
/*
* Check that server and host key lengths differ sufficiently. This
* is necessary to make double encryption work with rsaref. Oh, I
* hate software patents. I dont know if this can go? Niels
*/
if (options.server_key_bits >
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
SSH_KEY_BITS_RESERVED && options.server_key_bits <
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
SSH_KEY_BITS_RESERVED) {
options.server_key_bits =
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
SSH_KEY_BITS_RESERVED;
debug("Forcing server key to %d bits to make it differ from host key.",
options.server_key_bits);
}
}
if (use_privsep) {
struct passwd *pw;
struct stat st;
if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
fatal("Privilege separation user %s does not exist",
SSH_PRIVSEP_USER);
if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
(S_ISDIR(st.st_mode) == 0))
fatal("Missing privilege separation directory: %s",
_PATH_PRIVSEP_CHROOT_DIR);
#ifdef HAVE_CYGWIN
if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) &&
(st.st_uid != getuid () ||
(st.st_mode & (S_IWGRP|S_IWOTH)) != 0))
#else
if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
#endif
fatal("%s must be owned by root and not group or "
"world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
}
/* Configuration looks good, so exit if in test mode. */
if (test_flag)
exit(0);
/*
* Clear out any supplemental groups we may have inherited. This
* prevents inadvertent creation of files with bad modes (in the
* portable version at least, it's certainly possible for PAM
* to create a file, and we can't control the code in every
* module which might be used).
*/
if (setgroups(0, NULL) < 0)
debug("setgroups() failed: %.200s", strerror(errno));
if (rexec_flag) {
rexec_argv = xmalloc(sizeof(char *) * (rexec_argc + 2));
for (i = 0; i < rexec_argc; i++) {
debug("rexec_argv[%d]='%s'", i, saved_argv[i]);
rexec_argv[i] = saved_argv[i];
}
rexec_argv[rexec_argc] = "-R";
rexec_argv[rexec_argc + 1] = NULL;
}
/* Initialize the log (it is reinitialized below in case we forked). */
if (debug_flag && !inetd_flag)
log_stderr = 1;
log_init(__progname, options.log_level, options.log_facility, log_stderr);
/*
* If not in debugging mode, and not started from inetd, disconnect
* from the controlling terminal, and fork. The original process
* exits.
*/
if (!(debug_flag || inetd_flag || no_daemon_flag)) {
#ifdef TIOCNOTTY
int fd;
#endif /* TIOCNOTTY */
if (daemon(0, 0) < 0)
fatal("daemon() failed: %.200s", strerror(errno));
/* Disconnect from the controlling tty. */
#ifdef TIOCNOTTY
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
if (fd >= 0) {
(void) ioctl(fd, TIOCNOTTY, NULL);
close(fd);
}
#endif /* TIOCNOTTY */
}
/* Reinitialize the log (because of the fork above). */
log_init(__progname, options.log_level, options.log_facility, log_stderr);
/* Initialize the random number generator. */
arc4random_stir();
/* Chdir to the root directory so that the current disk can be
unmounted if desired. */
chdir("/");
/* ignore SIGPIPE */
signal(SIGPIPE, SIG_IGN);
/* Start listening for a socket, unless started from inetd. */
if (inetd_flag) {
int fd;
startup_pipe = -1;
if (rexeced_flag) {
close(REEXEC_CONFIG_PASS_FD);
sock_in = sock_out = dup(STDIN_FILENO);
if (!debug_flag) {
startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
close(REEXEC_STARTUP_PIPE_FD);
}
} else {
sock_in = dup(STDIN_FILENO);
sock_out = dup(STDOUT_FILENO);
}
/*
* We intentionally do not close the descriptors 0, 1, and 2
* as our code for setting the descriptors won't work if
* ttyfd happens to be one of those.
*/
if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
dup2(fd, STDIN_FILENO);
dup2(fd, STDOUT_FILENO);
if (fd > STDOUT_FILENO)
close(fd);
}
debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
if ((options.protocol & SSH_PROTO_1) &&
sensitive_data.server_key == NULL)
generate_ephemeral_server_key();
} else {
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, ai->ai_socktype,
ai->ai_protocol);
if (listen_sock < 0) {
/* kernel may not support ipv6 */
verbose("socket: %.100s", strerror(errno));
continue;
}
if (set_nonblock(listen_sock) == -1) {
close(listen_sock);
continue;
}
/*
* Set socket options.
* Allow local port reuse in TIME_WAIT.
*/
if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
&on, sizeof(on)) == -1)
error("setsockopt SO_REUSEADDR: %s", strerror(errno));
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) {
if (!ai->ai_next)
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. */
logit("SSH MITM Server listening on %s port %s.", ntop, strport);
if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
fatal("listen: %.100s", strerror(errno));
}
freeaddrinfo(options.listen_addrs);
if (!num_listen_socks)
fatal("Cannot bind any address.");
if (options.protocol & SSH_PROTO_1)
generate_ephemeral_server_key();
/*
* Arrange to restart on SIGHUP. The handler needs
* listen_sock.
*/
signal(SIGHUP, sighup_handler);
signal(SIGTERM, sigterm_handler);
signal(SIGQUIT, sigterm_handler);
/* Arrange SIGCHLD to be caught. */
signal(SIGCHLD, main_sigchld_handler);
/* Write out the pid file after the sigterm handler is setup */
if (!debug_flag) {
/*
* Record our pid in /var/run/sshd.pid to make it
* easier to kill the correct sshd. We don't want to
* do this before the bind above because the bind will
* fail if there already is a daemon, and this will
* overwrite any old pid in the file.
*/
f = fopen(options.pid_file, "wb");
if (f == NULL) {
error("Couldn't create pid file \"%s\": %s",
options.pid_file, strerror(errno));
} else {
fprintf(f, "%ld\n", (long) getpid());
fclose(f);
}
}
/* setup fd set for listen */
fdset = NULL;
maxfd = 0;
for (i = 0; i < num_listen_socks; i++)
if (listen_socks[i] > maxfd)
maxfd = listen_socks[i];
/* pipes connected to unauthenticated childs */
startup_pipes = xmalloc(options.max_startups * sizeof(int));
for (i = 0; i < options.max_startups; i++)
startup_pipes[i] = -1;
/*
* Stay listening for connections until the system crashes or
* the daemon is killed with a signal.
*/
for (;;) {
if (received_sighup)
sighup_restart();
if (fdset != NULL)
xfree(fdset);
fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
fdset = (fd_set *)xmalloc(fdsetsz);
memset(fdset, 0, fdsetsz);
for (i = 0; i < num_listen_socks; i++)
FD_SET(listen_socks[i], fdset);
for (i = 0; i < options.max_startups; i++)
if (startup_pipes[i] != -1)
FD_SET(startup_pipes[i], fdset);
/* Wait in select until there is a connection. */
ret = select(maxfd+1, fdset, NULL, NULL, NULL);
if (ret < 0 && errno != EINTR)
error("select: %.100s", strerror(errno));
if (received_sigterm) {
logit("Received signal %d; terminating.",
(int) received_sigterm);
close_listen_socks();
unlink(options.pid_file);
exit(255);
}
if (key_used && key_do_regen) {
generate_ephemeral_server_key();
key_used = 0;
key_do_regen = 0;
}
if (ret < 0)
continue;
for (i = 0; i < options.max_startups; i++)
if (startup_pipes[i] != -1 &&
FD_ISSET(startup_pipes[i], fdset)) {
/*
* the read end of the pipe is ready
* if the child has closed the pipe
* after successful authentication
* or if the child has died
*/
close(startup_pipes[i]);
startup_pipes[i] = -1;
startups--;
}
for (i = 0; i < num_listen_socks; i++) {
if (!FD_ISSET(listen_socks[i], fdset))
continue;
fromlen = sizeof(from);
debug("Awaiting client");
newsock = accept(listen_socks[i], (struct sockaddr *)&from,
&fromlen);
if (newsock < 0) {
if (errno != EINTR && errno != EWOULDBLOCK)
error("accept: %.100s", strerror(errno));
continue;
}
if (unset_nonblock(newsock) == -1) {
close(newsock);
continue;
}
if (drop_connection(startups) == 1) {
debug("drop connection #%d", startups);
close(newsock);
continue;
}
if (pipe(startup_p) == -1) {
close(newsock);
continue;
}
if (rexec_flag && socketpair(AF_UNIX,
SOCK_STREAM, 0, config_s) == -1) {
error("reexec socketpair: %s",
strerror(errno));
close(newsock);
close(startup_p[0]);
close(startup_p[1]);
continue;
}
for (j = 0; j < options.max_startups; j++)
if (startup_pipes[j] == -1) {
startup_pipes[j] = startup_p[0];
if (maxfd < startup_p[0])
maxfd = startup_p[0];
startups++;
break;
}
/*
* Got connection. Fork a child to handle it, unless
* we are in debugging mode.
*/
if (debug_flag) {
/*
* In debugging mode. Close the listening
* socket, and start processing the
* connection without forking.
*/
debug("Server will not fork when running in debugging mode.");
close_listen_socks();
sock_in = newsock;
sock_out = newsock;
close(startup_p[0]);
close(startup_p[1]);
startup_pipe = -1;
pid = getpid();
if (rexec_flag) {
send_rexec_state(config_s[0],
&cfg);
close(config_s[0]);
}
break;
} else {
/*
* Normal production daemon. Fork, and have
* the child process the connection. The
* parent continues listening.
*/
if ((pid = fork()) == 0) {
/*
* Child. Close the listening and max_startup
* sockets. Start using the accepted socket.
* Reinitialize logging (since our pid has
* changed). We break out of the loop to handle
* the connection.
*/
startup_pipe = startup_p[1];
close_startup_pipes();
close_listen_socks();
sock_in = newsock;
sock_out = newsock;
log_init(__progname, options.log_level, options.log_facility, log_stderr);
close(config_s[0]);
break;
}
}
/* Parent. Stay in the loop. */
if (pid < 0)
error("fork: %.100s", strerror(errno));
else
debug("Forked child %ld.", (long)pid);
close(startup_p[1]);
if (rexec_flag) {
send_rexec_state(config_s[0], &cfg);
close(config_s[0]);
close(config_s[1]);
}
/* Mark that the key has been used (it was "given" to the child). */
if ((options.protocol & SSH_PROTO_1) &&
key_used == 0) {
/* Schedule server key regeneration alarm. */
signal(SIGALRM, key_regeneration_alarm);
alarm(options.key_regeneration_time);
key_used = 1;
}
arc4random_stir();
/* Close the new socket (the child is now taking care of it). */
close(newsock);
}
/* child process check (or debug mode) */
if (num_listen_socks < 0)
break;
}
}
/* This is the child processing a new connection. */
setproctitle("%s", "[MITM]");
log_init("mitm-server", options.log_level,
options.log_facility, log_stderr);
alarm(0);
signal(SIGALRM, SIG_DFL);
signal(SIGHUP, SIG_DFL);
signal(SIGTERM, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGINT, SIG_DFL);
packet_set_connection(sock_in, sock_out);
sshd_exchange_identification(sock_in, sock_out);
packet_set_nonblocking();
/* perform the key exchange */
if (compat20)
do_ssh2_kex();
else
do_ssh1_kex();
mitm_ssh(sock_in);
/* Unreached */
exit(1);
}
/*
* return 1 if access is granted, 0 if not.
* side effect: sets key option flags
*/
int
auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
{
const char *cp;
int i;
/* reset options */
auth_clear_options();
if (!opts)
return 1;
while (*opts && *opts != ' ' && *opts != '\t') {
cp = "cert-authority";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
key_is_cert_authority = 1;
opts += strlen(cp);
goto next_option;
}
cp = "no-port-forwarding";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("Port forwarding disabled.");
no_port_forwarding_flag = 1;
opts += strlen(cp);
goto next_option;
}
cp = "no-agent-forwarding";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("Agent forwarding disabled.");
no_agent_forwarding_flag = 1;
opts += strlen(cp);
goto next_option;
}
cp = "no-X11-forwarding";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("X11 forwarding disabled.");
no_x11_forwarding_flag = 1;
opts += strlen(cp);
goto next_option;
}
cp = "no-pty";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("Pty allocation disabled.");
no_pty_flag = 1;
opts += strlen(cp);
goto next_option;
}
cp = "no-user-rc";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("User rc file execution disabled.");
no_user_rc = 1;
opts += strlen(cp);
goto next_option;
}
cp = "command=\"";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
opts += strlen(cp);
if (forced_command != NULL)
xfree(forced_command);
forced_command = xmalloc(strlen(opts) + 1);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
forced_command[i++] = '"';
continue;
}
forced_command[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(forced_command);
forced_command = NULL;
goto bad_option;
}
forced_command[i] = '\0';
auth_debug_add("Forced command.");
opts++;
goto next_option;
}
cp = "principals=\"";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
opts += strlen(cp);
if (authorized_principals != NULL)
xfree(authorized_principals);
authorized_principals = xmalloc(strlen(opts) + 1);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
authorized_principals[i++] = '"';
continue;
}
authorized_principals[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(authorized_principals);
authorized_principals = NULL;
goto bad_option;
}
authorized_principals[i] = '\0';
auth_debug_add("principals: %.900s",
authorized_principals);
opts++;
goto next_option;
}
cp = "environment=\"";
if (options.permit_user_env &&
strncasecmp(opts, cp, strlen(cp)) == 0) {
char *s;
struct envstring *new_envstring;
opts += strlen(cp);
s = xmalloc(strlen(opts) + 1);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
s[i++] = '"';
continue;
}
s[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(s);
goto bad_option;
}
s[i] = '\0';
auth_debug_add("Adding to environment: %.900s", s);
debug("Adding to environment: %.900s", s);
opts++;
new_envstring = xmalloc(sizeof(struct envstring));
new_envstring->s = s;
new_envstring->next = custom_environment;
custom_environment = new_envstring;
goto next_option;
}
cp = "from=\"";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
const char *remote_ip = get_remote_ipaddr();
const char *remote_host = get_canonical_hostname(
options.use_dns);
char *patterns = xmalloc(strlen(opts) + 1);
opts += strlen(cp);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
patterns[i++] = '"';
continue;
}
patterns[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(patterns);
goto bad_option;
}
patterns[i] = '\0';
opts++;
switch (match_host_and_ip(remote_host, remote_ip,
patterns)) {
case 1:
xfree(patterns);
/* Host name matches. */
goto next_option;
case -1:
debug("%.100s, line %lu: invalid criteria",
file, linenum);
auth_debug_add("%.100s, line %lu: "
"invalid criteria", file, linenum);
/* FALLTHROUGH */
case 0:
xfree(patterns);
logit("Authentication tried for %.100s with "
"correct key but not from a permitted "
"host (host=%.200s, ip=%.200s).",
pw->pw_name, remote_host, remote_ip);
auth_debug_add("Your host '%.200s' is not "
"permitted to use this key for login.",
remote_host);
break;
}
/* deny access */
return 0;
}
cp = "permitopen=\"";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
char *host, *p;
int port;
char *patterns = xmalloc(strlen(opts) + 1);
opts += strlen(cp);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
patterns[i++] = '"';
continue;
}
patterns[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing "
"end quote", file, linenum);
xfree(patterns);
goto bad_option;
}
patterns[i] = '\0';
opts++;
p = patterns;
host = hpdelim(&p);
if (host == NULL || strlen(host) >= NI_MAXHOST) {
debug("%.100s, line %lu: Bad permitopen "
"specification <%.100s>", file, linenum,
patterns);
auth_debug_add("%.100s, line %lu: "
"Bad permitopen specification", file,
linenum);
xfree(patterns);
goto bad_option;
}
host = cleanhostname(host);
if (p == NULL || (port = a2port(p)) <= 0) {
debug("%.100s, line %lu: Bad permitopen port "
"<%.100s>", file, linenum, p ? p : "");
auth_debug_add("%.100s, line %lu: "
"Bad permitopen port", file, linenum);
xfree(patterns);
goto bad_option;
}
if (options.allow_tcp_forwarding)
channel_add_permitted_opens(host, port);
xfree(patterns);
goto next_option;
}
cp = "tunnel=\"";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
char *tun = NULL;
opts += strlen(cp);
tun = xmalloc(strlen(opts) + 1);
i = 0;
while (*opts) {
if (*opts == '"')
break;
tun[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(tun);
forced_tun_device = -1;
goto bad_option;
}
tun[i] = '\0';
forced_tun_device = a2tun(tun, NULL);
xfree(tun);
if (forced_tun_device == SSH_TUNID_ERR) {
debug("%.100s, line %lu: invalid tun device",
file, linenum);
auth_debug_add("%.100s, line %lu: invalid tun device",
file, linenum);
forced_tun_device = -1;
goto bad_option;
}
auth_debug_add("Forced tun device: %d", forced_tun_device);
opts++;
goto next_option;
}
next_option:
/*
* Skip the comma, and move to the next option
* (or break out if there are no more).
*/
if (!*opts)
fatal("Bugs in auth-options.c option processing.");
if (*opts == ' ' || *opts == '\t')
break; /* End of options. */
if (*opts != ',')
goto bad_option;
opts++;
/* Process the next option. */
}
/* grant access */
return 1;
bad_option:
logit("Bad options in %.100s file, line %lu: %.50s",
file, linenum, opts);
auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
file, linenum, opts);
/* deny access */
return 0;
}
/*
* return 1 if access is granted, 0 if not.
* side effect: sets key option flags
*/
int
auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
{
const char *cp;
int i;
/* reset options */
auth_clear_options();
if (!opts)
return 1;
while (*opts && *opts != ' ' && *opts != '\t') {
cp = "no-port-forwarding";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("Port forwarding disabled.");
no_port_forwarding_flag = 1;
opts += strlen(cp);
goto next_option;
}
cp = "no-agent-forwarding";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("Agent forwarding disabled.");
no_agent_forwarding_flag = 1;
opts += strlen(cp);
goto next_option;
}
cp = "no-X11-forwarding";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("X11 forwarding disabled.");
no_x11_forwarding_flag = 1;
opts += strlen(cp);
goto next_option;
}
cp = "no-pty";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
auth_debug_add("Pty allocation disabled.");
no_pty_flag = 1;
opts += strlen(cp);
goto next_option;
}
cp = "command=\"";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
opts += strlen(cp);
forced_command = xmalloc(strlen(opts) + 1);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
forced_command[i++] = '"';
continue;
}
forced_command[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(forced_command);
forced_command = NULL;
goto bad_option;
}
forced_command[i] = 0;
auth_debug_add("Forced command: %.900s", forced_command);
opts++;
goto next_option;
}
cp = "environment=\"";
if (options.permit_user_env &&
strncasecmp(opts, cp, strlen(cp)) == 0) {
char *s;
struct envstring *new_envstring;
opts += strlen(cp);
s = xmalloc(strlen(opts) + 1);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
s[i++] = '"';
continue;
}
s[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(s);
goto bad_option;
}
s[i] = 0;
auth_debug_add("Adding to environment: %.900s", s);
debug("Adding to environment: %.900s", s);
opts++;
new_envstring = xmalloc(sizeof(struct envstring));
new_envstring->s = s;
new_envstring->next = custom_environment;
custom_environment = new_envstring;
goto next_option;
}
cp = "from=\"";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
const char *remote_ip = get_remote_ipaddr();
const char *remote_host = get_canonical_hostname(
options.verify_reverse_mapping);
char *patterns = xmalloc(strlen(opts) + 1);
opts += strlen(cp);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
patterns[i++] = '"';
continue;
}
patterns[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(patterns);
goto bad_option;
}
patterns[i] = 0;
opts++;
if (match_host_and_ip(remote_host, remote_ip,
patterns) != 1) {
xfree(patterns);
log("Authentication tried for %.100s with "
"correct key but not from a permitted "
"host (host=%.200s, ip=%.200s).",
pw->pw_name, remote_host, remote_ip);
auth_debug_add("Your host '%.200s' is not "
"permitted to use this key for login.",
remote_host);
/* deny access */
return 0;
}
xfree(patterns);
/* Host name matches. */
goto next_option;
}
cp = "permitopen=\"";
if (strncasecmp(opts, cp, strlen(cp)) == 0) {
char host[256], sport[6];
u_short port;
char *patterns = xmalloc(strlen(opts) + 1);
opts += strlen(cp);
i = 0;
while (*opts) {
if (*opts == '"')
break;
if (*opts == '\\' && opts[1] == '"') {
opts += 2;
patterns[i++] = '"';
continue;
}
patterns[i++] = *opts++;
}
if (!*opts) {
debug("%.100s, line %lu: missing end quote",
file, linenum);
auth_debug_add("%.100s, line %lu: missing end quote",
file, linenum);
xfree(patterns);
goto bad_option;
}
patterns[i] = 0;
opts++;
if (sscanf(patterns, "%255[^:]:%5[0-9]", host, sport) != 2 &&
sscanf(patterns, "%255[^/]/%5[0-9]", host, sport) != 2) {
debug("%.100s, line %lu: Bad permitopen specification "
"<%.100s>", file, linenum, patterns);
auth_debug_add("%.100s, line %lu: "
"Bad permitopen specification", file, linenum);
xfree(patterns);
goto bad_option;
}
if ((port = a2port(sport)) == 0) {
debug("%.100s, line %lu: Bad permitopen port <%.100s>",
file, linenum, sport);
auth_debug_add("%.100s, line %lu: "
"Bad permitopen port", file, linenum);
xfree(patterns);
goto bad_option;
}
if (options.allow_tcp_forwarding)
channel_add_permitted_opens(host, port);
xfree(patterns);
goto next_option;
}
next_option:
/*
* Skip the comma, and move to the next option
* (or break out if there are no more).
*/
if (!*opts)
fatal("Bugs in auth-options.c option processing.");
if (*opts == ' ' || *opts == '\t')
break; /* End of options. */
if (*opts != ',')
goto bad_option;
opts++;
/* Process the next option. */
}
if (!use_privsep)
auth_debug_send();
/* grant access */
return 1;
bad_option:
log("Bad options in %.100s file, line %lu: %.50s",
file, linenum, opts);
auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
file, linenum, opts);
if (!use_privsep)
auth_debug_send();
/* deny access */
return 0;
}
/*
* Main program for the ssh client.
*/
int
main(int ac, char **av)
{
int i, opt, exit_status;
u_short fwd_port, fwd_host_port;
char sfwd_port[6], sfwd_host_port[6];
char *p, *cp, buf[256];
struct stat st;
struct passwd *pw;
int dummy;
extern int optind, optreset;
extern char *optarg;
__progname = get_progname(av[0]);
init_rng();
/*
* 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();
/*
* 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).
*/
PRIV_END;
#ifdef HAVE_SETRLIMIT
/* 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));
}
#endif
/* Get user data. */
pw = getpwuid(original_real_uid);
if (!pw) {
log("You don't exist, go away!");
exit(1);
}
/* Take a copy of the returned structure. */
pw = pwcopy(pw);
/*
* 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);
/* Initialize option structure to indicate that no values have been set. */
initialize_options(&options);
/* Parse command-line arguments. */
host = NULL;
again:
while ((opt = getopt(ac, av,
"1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:NPR:TVX")) != -1) {
switch (opt) {
case '1':
options.protocol = SSH_PROTO_1;
break;
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': /* deprecated */
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.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 'I':
#ifdef SMARTCARD
options.smartcard_device = xstrdup(optarg);
#else
fprintf(stderr, "no support for smartcards.\n");
#endif
break;
case 't':
if (tty_flag)
force_tty_flag = 1;
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.");
/* fallthrough */
case 'V':
fprintf(stderr,
"%s, SSH protocols %d.%d/%d.%d, OpenSSL 0x%8.8lx\n",
SSH_VERSION,
PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1,
PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2,
SSLeay());
if (opt == 'V')
exit(0);
break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
break;
case 'e':
if (optarg[0] == '^' && optarg[2] == 0 &&
(u_char) optarg[1] >= 64 &&
(u_char) optarg[1] < 128)
options.escape_char = (u_char) optarg[1] & 31;
else if (strlen(optarg) == 1)
options.escape_char = (u_char) optarg[0];
else if (strcmp(optarg, "none") == 0)
options.escape_char = SSH_ESCAPECHAR_NONE;
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 */
options.cipher = cipher_number(optarg);
if (options.cipher == -1) {
fprintf(stderr,
"Unknown cipher type '%s'\n",
optarg);
exit(1);
}
if (options.cipher == SSH_CIPHER_3DES)
options.ciphers = "3des-cbc";
else if (options.cipher == SSH_CIPHER_BLOWFISH)
options.ciphers = "blowfish-cbc";
else
options.ciphers = (char *)-1;
}
break;
case 'm':
if (mac_valid(optarg))
options.macs = xstrdup(optarg);
else {
fprintf(stderr, "Unknown mac type '%s'\n",
optarg);
exit(1);
}
break;
case 'p':
options.port = a2port(optarg);
if (options.port == 0) {
fprintf(stderr, "Bad port '%s'\n", optarg);
exit(1);
}
break;
case 'l':
options.user = optarg;
break;
case 'L':
case 'R':
if (sscanf(optarg, "%5[0-9]:%255[^:]:%5[0-9]",
sfwd_port, buf, sfwd_host_port) != 3 &&
sscanf(optarg, "%5[0-9]/%255[^/]/%5[0-9]",
sfwd_port, buf, sfwd_host_port) != 3) {
fprintf(stderr,
"Bad forwarding specification '%s'\n",
optarg);
usage();
/* NOTREACHED */
}
if ((fwd_port = a2port(sfwd_port)) == 0 ||
(fwd_host_port = a2port(sfwd_host_port)) == 0) {
fprintf(stderr,
"Bad forwarding port(s) '%s'\n", optarg);
exit(1);
}
if (opt == 'L')
add_local_forward(&options, fwd_port, buf,
fwd_host_port);
else if (opt == 'R')
add_remote_forward(&options, fwd_port, buf,
fwd_host_port);
break;
case 'D':
fwd_port = a2port(optarg);
if (fwd_port == 0) {
fprintf(stderr, "Bad dynamic port '%s'\n",
optarg);
exit(1);
}
add_local_forward(&options, fwd_port, "socks4", 0);
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;
case 's':
subsystem_flag = 1;
break;
case 'b':
options.bind_address = optarg;
break;
case 'F':
config = optarg;
break;
default:
usage();
}
}
ac -= optind;
av += optind;
if (ac > 0 && !host && **av != '-') {
if (strrchr(*av, '@')) {
p = xstrdup(*av);
cp = strrchr(p, '@');
if (cp == NULL || cp == p)
usage();
options.user = p;
*cp = '\0';
host = ++cp;
} else
host = *av;
if (ac > 1) {
optind = optreset = 1;
goto again;
}
ac--, av++;
}
/* Check that we got a host name. */
if (!host)
usage();
SSLeay_add_all_algorithms();
ERR_load_crypto_strings();
channel_set_af(IPv4or6);
/* 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 (!ac) {
/* No command specified - execute shell on a tty. */
tty_flag = 1;
if (subsystem_flag) {
fprintf(stderr,
"You must specify a subsystem to invoke.\n");
usage();
}
} else {
/* A command has been specified. Store it into the buffer. */
for (i = 0; i < ac; i++) {
if (i)
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;
/* Force no tty */
if (no_tty_flag)
tty_flag = 0;
/* Do not allocate a tty if stdin is not a tty. */
if (!isatty(fileno(stdin)) && !force_tty_flag) {
if (tty_flag)
log("Pseudo-terminal will not be allocated because stdin is not a terminal.");
tty_flag = 0;
}
/*
* Initialize "log" output. Since we are the client all output
* actually goes to stderr.
*/
log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
SYSLOG_FACILITY_USER, 1);
/*
* Read per-user configuration file. Ignore the system wide config
* file if the user specifies a config file on the command line.
*/
if (config != NULL) {
if (!read_config_file(config, host, &options))
fatal("Can't open user config file %.100s: "
"%.100s", config, strerror(errno));
} else {
snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
_PATH_SSH_USER_CONFFILE);
(void)read_config_file(buf, host, &options);
/* Read systemwide configuration file after use config. */
(void)read_config_file(_PATH_HOST_CONFIG_FILE, host, &options);
}
/* Fill configuration defaults. */
fill_default_options(&options);
/* reinit */
log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
seed_rng();
if (options.user == NULL)
options.user = xstrdup(pw->pw_name);
if (options.hostname != NULL)
host = options.hostname;
if (options.proxy_command != NULL &&
strcmp(options.proxy_command, "none") == 0)
options.proxy_command = NULL;
/* Disable rhosts authentication if not running as root. */
#ifdef HAVE_CYGWIN
/* Ignore uid if running under Windows */
if (!options.use_privileged_port) {
#else
if (original_effective_uid != 0 || !options.use_privileged_port) {
#endif
debug("Rhosts Authentication disabled, "
"originating port will not be trusted.");
options.rhosts_authentication = 0;
}
/* Open a connection to the remote host. */
if (ssh_connect(host, &hostaddr, options.port, IPv4or6,
options.connection_attempts,
#ifdef HAVE_CYGWIN
options.use_privileged_port,
#else
original_effective_uid == 0 && options.use_privileged_port,
#endif
options.proxy_command) != 0)
exit(1);
/*
* 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 we cannot access the private keys, load the public keys
* instead and try to execute the ssh-keysign helper instead.
*/
sensitive_data.nkeys = 0;
sensitive_data.keys = NULL;
sensitive_data.external_keysign = 0;
if (options.rhosts_rsa_authentication ||
options.hostbased_authentication) {
sensitive_data.nkeys = 3;
sensitive_data.keys = xmalloc(sensitive_data.nkeys *
sizeof(Key));
PRIV_START;
sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
_PATH_HOST_KEY_FILE, "", NULL);
sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
_PATH_HOST_DSA_KEY_FILE, "", NULL);
sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
_PATH_HOST_RSA_KEY_FILE, "", NULL);
PRIV_END;
if (options.hostbased_authentication == 1 &&
sensitive_data.keys[0] == NULL &&
sensitive_data.keys[1] == NULL &&
sensitive_data.keys[2] == NULL) {
sensitive_data.keys[1] = key_load_public(
_PATH_HOST_DSA_KEY_FILE, NULL);
sensitive_data.keys[2] = key_load_public(
_PATH_HOST_RSA_KEY_FILE, NULL);
sensitive_data.external_keysign = 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.
*/
seteuid(original_real_uid);
setuid(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%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
if (stat(buf, &st) < 0)
if (mkdir(buf, 0700) < 0)
error("Could not create directory '%.200s'.", buf);
/* load options.identity_files */
load_public_identity_files();
/* Expand ~ in known host file names. */
/* XXX mem-leaks: */
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);
signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
/* Log into the remote system. This never returns if the login fails. */
ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
/* We no longer need the private host keys. Clear them now. */
if (sensitive_data.nkeys != 0) {
for (i = 0; i < sensitive_data.nkeys; i++) {
if (sensitive_data.keys[i] != NULL) {
/* Destroys contents safely */
debug3("clear hostkey %d", i);
key_free(sensitive_data.keys[i]);
sensitive_data.keys[i] = NULL;
}
}
xfree(sensitive_data.keys);
}
for (i = 0; i < options.num_identity_files; i++) {
if (options.identity_files[i]) {
xfree(options.identity_files[i]);
options.identity_files[i] = NULL;
}
if (options.identity_keys[i]) {
key_free(options.identity_keys[i]);
options.identity_keys[i] = NULL;
}
}
exit_status = compat20 ? ssh_session2() : ssh_session();
packet_close();
/*
* Send SIGHUP to proxy command if used. We don't wait() in
* case it hangs and instead rely on init to reap the child
*/
if (proxy_command_pid > 1)
kill(proxy_command_pid, SIGHUP);
return exit_status;
}
static void
x11_get_proto(char **_proto, char **_data)
{
char line[512];
static char proto[512], data[512];
FILE *f;
int got_data = 0, i;
char *display;
struct stat st;
*_proto = proto;
*_data = data;
proto[0] = data[0] = '\0';
if (!options.xauth_location ||
(stat(options.xauth_location, &st) == -1)) {
debug("No xauth program.");
} else {
if ((display = getenv("DISPLAY")) == NULL) {
debug("x11_get_proto: DISPLAY not set");
return;
}
/* Try to get Xauthority information for the display. */
if (strncmp(display, "localhost:", 10) == 0)
/*
* Handle FamilyLocal case where $DISPLAY does
* not match an authorization entry. For this we
* just try "xauth list unix:displaynum.screennum".
* XXX: "localhost" match to determine FamilyLocal
* is not perfect.
*/
snprintf(line, sizeof line, "%s list unix:%s 2>"
_PATH_DEVNULL, options.xauth_location, display+10);
else
snprintf(line, sizeof line, "%s list %.200s 2>"
_PATH_DEVNULL, options.xauth_location, display);
debug2("x11_get_proto: %s", line);
f = popen(line, "r");
if (f && fgets(line, sizeof(line), f) &&
sscanf(line, "%*s %511s %511s", 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;
log("Warning: No xauth data; using fake authentication data for X11 forwarding.");
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;
}
}
int
process_config_line(Options *options, const char *host,
char *line, const char *filename, int linenum,
int *activep)
{
char buf[256], *s, **charptr, *endofnumber, *keyword, *arg;
int opcode, *intptr, value;
size_t len;
u_short fwd_port, fwd_host_port;
char sfwd_host_port[6];
/* Strip trailing whitespace */
for(len = strlen(line) - 1; len > 0; len--) {
if (strchr(WHITESPACE, line[len]) == NULL)
break;
line[len] = '\0';
}
s = line;
/* Get the keyword. (Each line is supposed to begin with a keyword). */
keyword = strdelim(&s);
/* Ignore leading whitespace. */
if (*keyword == '\0')
keyword = strdelim(&s);
if (keyword == NULL || !*keyword || *keyword == '\n' || *keyword == '#')
return 0;
opcode = parse_token(keyword, filename, linenum);
switch (opcode) {
case oBadOption:
/* don't panic, but count bad options */
return -1;
/* NOTREACHED */
case oConnectTimeout:
intptr = &options->connection_timeout;
parse_time:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: missing time value.",
filename, linenum);
if ((value = convtime(arg)) == -1)
fatal("%s line %d: invalid time value.",
filename, linenum);
if (*intptr == -1)
*intptr = value;
break;
case oForwardAgent:
intptr = &options->forward_agent;
parse_flag:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing yes/no argument.", filename, linenum);
value = 0; /* To avoid compiler warning... */
if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = 1;
else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = 0;
else
fatal("%.200s line %d: Bad yes/no argument.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oForwardX11:
intptr = &options->forward_x11;
goto parse_flag;
case oForwardX11Trusted:
intptr = &options->forward_x11_trusted;
goto parse_flag;
case oGatewayPorts:
intptr = &options->gateway_ports;
goto parse_flag;
case oUsePrivilegedPort:
intptr = &options->use_privileged_port;
goto parse_flag;
case oPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case oKbdInteractiveAuthentication:
intptr = &options->kbd_interactive_authentication;
goto parse_flag;
case oKbdInteractiveDevices:
charptr = &options->kbd_interactive_devices;
goto parse_string;
case oPubkeyAuthentication:
intptr = &options->pubkey_authentication;
goto parse_flag;
case oRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case oRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case oHostbasedAuthentication:
intptr = &options->hostbased_authentication;
goto parse_flag;
case oChallengeResponseAuthentication:
intptr = &options->challenge_response_authentication;
goto parse_flag;
case oGssAuthentication:
intptr = &options->gss_authentication;
goto parse_flag;
case oGssDelegateCreds:
intptr = &options->gss_deleg_creds;
goto parse_flag;
case oBatchMode:
intptr = &options->batch_mode;
goto parse_flag;
case oCheckHostIP:
intptr = &options->check_host_ip;
goto parse_flag;
case oVerifyHostKeyDNS:
intptr = &options->verify_host_key_dns;
goto parse_yesnoask;
case oStrictHostKeyChecking:
intptr = &options->strict_host_key_checking;
parse_yesnoask:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing yes/no/ask argument.",
filename, linenum);
value = 0; /* To avoid compiler warning... */
if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = 1;
else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = 0;
else if (strcmp(arg, "ask") == 0)
value = 2;
else
fatal("%.200s line %d: Bad yes/no/ask argument.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oCompression:
intptr = &options->compression;
goto parse_flag;
case oTCPKeepAlive:
intptr = &options->tcp_keep_alive;
goto parse_flag;
case oNoHostAuthenticationForLocalhost:
intptr = &options->no_host_authentication_for_localhost;
goto parse_flag;
case oNumberOfPasswordPrompts:
intptr = &options->number_of_password_prompts;
goto parse_int;
case oCompressionLevel:
intptr = &options->compression_level;
goto parse_int;
case oRekeyLimit:
intptr = &options->rekey_limit;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] < '0' || arg[0] > '9')
fatal("%.200s line %d: Bad number.", filename, linenum);
value = strtol(arg, &endofnumber, 10);
if (arg == endofnumber)
fatal("%.200s line %d: Bad number.", filename, linenum);
switch (toupper(*endofnumber)) {
case 'K':
value *= 1<<10;
break;
case 'M':
value *= 1<<20;
break;
case 'G':
value *= 1<<30;
break;
}
if (*activep && *intptr == -1)
*intptr = value;
break;
case oIdentityFile:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (*activep) {
intptr = &options->num_identity_files;
if (*intptr >= SSH_MAX_IDENTITY_FILES)
fatal("%.200s line %d: Too many identity files specified (max %d).",
filename, linenum, SSH_MAX_IDENTITY_FILES);
charptr = &options->identity_files[*intptr];
*charptr = xstrdup(arg);
*intptr = *intptr + 1;
}
break;
case oXAuthLocation:
charptr=&options->xauth_location;
goto parse_string;
case oUser:
charptr = &options->user;
parse_string:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (*activep && *charptr == NULL)
*charptr = xstrdup(arg);
break;
case oGlobalKnownHostsFile:
charptr = &options->system_hostfile;
goto parse_string;
case oUserKnownHostsFile:
charptr = &options->user_hostfile;
goto parse_string;
case oGlobalKnownHostsFile2:
charptr = &options->system_hostfile2;
goto parse_string;
case oUserKnownHostsFile2:
charptr = &options->user_hostfile2;
goto parse_string;
case oHostName:
charptr = &options->hostname;
goto parse_string;
case oHostKeyAlias:
charptr = &options->host_key_alias;
goto parse_string;
case oPreferredAuthentications:
charptr = &options->preferred_authentications;
goto parse_string;
case oBindAddress:
charptr = &options->bind_address;
goto parse_string;
case oSmartcardDevice:
charptr = &options->smartcard_device;
goto parse_string;
case oProxyCommand:
if (s == NULL)
fatal("%.200s line %d: Missing argument.", filename, linenum);
charptr = &options->proxy_command;
len = strspn(s, WHITESPACE "=");
if (*activep && *charptr == NULL)
*charptr = xstrdup(s + len);
return 0;
case oPort:
intptr = &options->port;
parse_int:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] < '0' || arg[0] > '9')
fatal("%.200s line %d: Bad number.", filename, linenum);
/* Octal, decimal, or hex format? */
value = strtol(arg, &endofnumber, 0);
if (arg == endofnumber)
fatal("%.200s line %d: Bad number.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oConnectionAttempts:
intptr = &options->connection_attempts;
goto parse_int;
case oCipher:
intptr = &options->cipher;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = cipher_number(arg);
if (value == -1)
fatal("%.200s line %d: Bad cipher '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *intptr == -1)
*intptr = value;
break;
case oCiphers:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(arg))
fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->ciphers == NULL)
options->ciphers = xstrdup(arg);
break;
case oMacs:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!mac_valid(arg))
fatal("%.200s line %d: Bad SSH2 Mac spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->macs == NULL)
options->macs = xstrdup(arg);
break;
case oHostKeyAlgorithms:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!key_names_valid2(arg))
fatal("%.200s line %d: Bad protocol 2 host key algorithms '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->hostkeyalgorithms == NULL)
options->hostkeyalgorithms = xstrdup(arg);
break;
case oProtocol:
intptr = &options->protocol;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = proto_spec(arg);
if (value == SSH_PROTO_UNKNOWN)
fatal("%.200s line %d: Bad protocol spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
case oLogLevel:
intptr = (int *) &options->log_level;
arg = strdelim(&s);
value = log_level_number(arg);
if (value == SYSLOG_LEVEL_NOT_SET)
fatal("%.200s line %d: unsupported log level '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && (LogLevel) *intptr == SYSLOG_LEVEL_NOT_SET)
*intptr = (LogLevel) value;
break;
case oLocalForward:
case oRemoteForward:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing port argument.",
filename, linenum);
if ((fwd_port = a2port(arg)) == 0)
fatal("%.200s line %d: Bad listen port.",
filename, linenum);
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing second argument.",
filename, linenum);
if (sscanf(arg, "%255[^:]:%5[0-9]", buf, sfwd_host_port) != 2 &&
sscanf(arg, "%255[^/]/%5[0-9]", buf, sfwd_host_port) != 2)
fatal("%.200s line %d: Bad forwarding specification.",
filename, linenum);
if ((fwd_host_port = a2port(sfwd_host_port)) == 0)
fatal("%.200s line %d: Bad forwarding port.",
filename, linenum);
if (*activep) {
if (opcode == oLocalForward)
add_local_forward(options, fwd_port, buf,
fwd_host_port);
else if (opcode == oRemoteForward)
add_remote_forward(options, fwd_port, buf,
fwd_host_port);
}
break;
case oDynamicForward:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing port argument.",
filename, linenum);
fwd_port = a2port(arg);
if (fwd_port == 0)
fatal("%.200s line %d: Badly formatted port number.",
filename, linenum);
if (*activep)
add_local_forward(options, fwd_port, "socks", 0);
break;
case oClearAllForwardings:
intptr = &options->clear_forwardings;
goto parse_flag;
case oHost:
*activep = 0;
while ((arg = strdelim(&s)) != NULL && *arg != '\0')
if (match_pattern(host, arg)) {
debug("Applying options for %.100s", arg);
*activep = 1;
break;
}
/* Avoid garbage check below, as strdelim is done. */
return 0;
case oEscapeChar:
intptr = &options->escape_char;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] == '^' && arg[2] == 0 &&
(u_char) arg[1] >= 64 && (u_char) arg[1] < 128)
value = (u_char) arg[1] & 31;
else if (strlen(arg) == 1)
value = (u_char) arg[0];
else if (strcmp(arg, "none") == 0)
value = SSH_ESCAPECHAR_NONE;
else {
fatal("%.200s line %d: Bad escape character.",
filename, linenum);
/* NOTREACHED */
value = 0; /* Avoid compiler warning. */
}
if (*activep && *intptr == -1)
*intptr = value;
break;
case oAddressFamily:
arg = strdelim(&s);
intptr = &options->address_family;
if (strcasecmp(arg, "inet") == 0)
value = AF_INET;
else if (strcasecmp(arg, "inet6") == 0)
value = AF_INET6;
else if (strcasecmp(arg, "any") == 0)
value = AF_UNSPEC;
else
fatal("Unsupported AddressFamily \"%s\"", arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oEnableSSHKeysign:
intptr = &options->enable_ssh_keysign;
goto parse_flag;
case oIdentitiesOnly:
intptr = &options->identities_only;
goto parse_flag;
case oServerAliveInterval:
intptr = &options->server_alive_interval;
goto parse_time;
case oServerAliveCountMax:
intptr = &options->server_alive_count_max;
goto parse_int;
case oDeprecated:
debug("%s line %d: Deprecated option \"%s\"",
filename, linenum, keyword);
return 0;
case oUnsupported:
error("%s line %d: Unsupported option \"%s\"",
filename, linenum, keyword);
return 0;
default:
fatal("process_config_line: Unimplemented opcode %d", opcode);
}
/* Check that there is no garbage at end of line. */
if ((arg = strdelim(&s)) != NULL && *arg != '\0') {
fatal("%.200s line %d: garbage at end of line; \"%.200s\".",
filename, linenum, arg);
}
return 0;
}
int
main(int argc, char **argv)
{
int ch, fflag, tflag, status, n;
char **newargv;
const char *errstr;
extern char *optarg;
extern int optind;
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
setlocale(LC_CTYPE, "");
/* Copy argv, because we modify it */
newargv = xcalloc(MAXIMUM(argc + 1, 1), sizeof(*newargv));
for (n = 0; n < argc; n++)
newargv[n] = xstrdup(argv[n]);
argv = newargv;
memset(&args, '\0', sizeof(args));
memset(&remote_remote_args, '\0', sizeof(remote_remote_args));
args.list = remote_remote_args.list = NULL;
addargs(&args, "%s", ssh_program);
addargs(&args, "-x");
addargs(&args, "-oForwardAgent=no");
addargs(&args, "-oPermitLocalCommand=no");
addargs(&args, "-oClearAllForwardings=yes");
addargs(&args, "-oRemoteCommand=none");
addargs(&args, "-oRequestTTY=no");
fflag = tflag = 0;
while ((ch = getopt(argc, argv, "dfl:prtvBCc:i:P:q12346S:o:F:")) != -1)
switch (ch) {
/* User-visible flags. */
case '1':
fatal("SSH protocol v.1 is no longer supported");
break;
case '2':
/* Ignored */
break;
case '4':
case '6':
case 'C':
addargs(&args, "-%c", ch);
addargs(&remote_remote_args, "-%c", ch);
break;
case '3':
throughlocal = 1;
break;
case 'o':
case 'c':
case 'i':
case 'F':
addargs(&remote_remote_args, "-%c", ch);
addargs(&remote_remote_args, "%s", optarg);
addargs(&args, "-%c", ch);
addargs(&args, "%s", optarg);
break;
case 'P':
sshport = a2port(optarg);
if (sshport <= 0)
fatal("bad port \"%s\"\n", optarg);
break;
case 'B':
addargs(&remote_remote_args, "-oBatchmode=yes");
addargs(&args, "-oBatchmode=yes");
break;
case 'l':
limit_kbps = strtonum(optarg, 1, 100 * 1024 * 1024,
&errstr);
if (errstr != NULL)
usage();
limit_kbps *= 1024; /* kbps */
bandwidth_limit_init(&bwlimit, limit_kbps, COPY_BUFLEN);
break;
case 'p':
pflag = 1;
break;
case 'r':
iamrecursive = 1;
break;
case 'S':
ssh_program = xstrdup(optarg);
break;
case 'v':
addargs(&args, "-v");
addargs(&remote_remote_args, "-v");
verbose_mode = 1;
break;
case 'q':
addargs(&args, "-q");
addargs(&remote_remote_args, "-q");
showprogress = 0;
break;
/* Server options. */
case 'd':
targetshouldbedirectory = 1;
break;
case 'f': /* "from" */
iamremote = 1;
fflag = 1;
break;
case 't': /* "to" */
iamremote = 1;
tflag = 1;
break;
default:
usage();
}
argc -= optind;
argv += optind;
if ((pwd = getpwuid(userid = getuid())) == NULL)
fatal("unknown user %u", (u_int) userid);
if (!isatty(STDOUT_FILENO))
showprogress = 0;
if (pflag) {
/* Cannot pledge: -p allows setuid/setgid files... */
} else {
#ifdef __OpenBSD__
if (pledge("stdio rpath wpath cpath fattr tty proc exec",
NULL) == -1) {
perror("pledge");
exit(1);
}
#endif
}
remin = STDIN_FILENO;
remout = STDOUT_FILENO;
if (fflag) {
/* Follow "protocol", send data. */
(void) response();
source(argc, argv);
exit(errs != 0);
}
if (tflag) {
/* Receive data. */
sink(argc, argv);
exit(errs != 0);
}
if (argc < 2)
usage();
if (argc > 2)
targetshouldbedirectory = 1;
remin = remout = -1;
do_cmd_pid = -1;
/* Command to be executed on remote system using "ssh". */
(void) snprintf(cmd, sizeof cmd, "scp%s%s%s%s",
verbose_mode ? " -v" : "",
iamrecursive ? " -r" : "", pflag ? " -p" : "",
targetshouldbedirectory ? " -d" : "");
(void) signal(SIGPIPE, lostconn);
if (colon(argv[argc - 1])) /* Dest is remote host. */
toremote(argc, argv);
else {
if (targetshouldbedirectory)
verifydir(argv[argc - 1]);
tolocal(argc, argv); /* Dest is local host. */
}
/*
* Finally check the exit status of the ssh process, if one was forked
* and no error has occurred yet
*/
if (do_cmd_pid != -1 && errs == 0) {
if (remin != -1)
(void) close(remin);
if (remout != -1)
(void) close(remout);
if (waitpid(do_cmd_pid, &status, 0) == -1)
errs = 1;
else {
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
errs = 1;
}
}
exit(errs != 0);
}
int
main(int argc, char **argv)
{
int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
int opt, fopt_count = 0;
char *tname;
extern int optind;
extern char *optarg;
TAILQ_INIT(&tq);
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
if (argc <= 1)
usage();
while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
switch (opt) {
case 'H':
hash_hosts = 1;
break;
case 'p':
ssh_port = a2port(optarg);
if (ssh_port <= 0) {
fprintf(stderr, "Bad port '%s'\n", optarg);
exit(1);
}
break;
case 'T':
timeout = convtime(optarg);
if (timeout == -1 || timeout == 0) {
fprintf(stderr, "Bad timeout '%s'\n", optarg);
usage();
}
break;
case 'v':
if (!debug_flag) {
debug_flag = 1;
log_level = SYSLOG_LEVEL_DEBUG1;
}
else if (log_level < SYSLOG_LEVEL_DEBUG3)
log_level++;
else
fatal("Too high debugging level.");
break;
case 'f':
if (strcmp(optarg, "-") == 0)
optarg = NULL;
argv[fopt_count++] = optarg;
break;
case 't':
get_keytypes = 0;
tname = strtok(optarg, ",");
while (tname) {
int type = key_type_from_name(tname);
switch (type) {
case KEY_RSA1:
get_keytypes |= KT_RSA1;
break;
case KEY_DSA:
get_keytypes |= KT_DSA;
break;
case KEY_RSA:
get_keytypes |= KT_RSA;
break;
case KEY_UNSPEC:
fatal("unknown key type %s", tname);
}
tname = strtok(NULL, ",");
}
break;
case '4':
IPv4or6 = AF_INET;
break;
case '6':
IPv4or6 = AF_INET6;
break;
case '?':
default:
usage();
}
}
if (optind == argc && !fopt_count)
usage();
log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
maxfd = fdlim_get(1);
if (maxfd < 0)
fatal("%s: fdlim_get: bad value", __progname);
if (maxfd > MAXMAXFD)
maxfd = MAXMAXFD;
if (MAXCON <= 0)
fatal("%s: not enough file descriptors", __progname);
if (maxfd > fdlim_get(0))
fdlim_set(maxfd);
fdcon = xcalloc(maxfd, sizeof(con));
read_wait_nfdset = howmany(maxfd, NFDBITS);
read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
if (fopt_count) {
Linebuf *lb;
char *line;
int j;
for (j = 0; j < fopt_count; j++) {
lb = Linebuf_alloc(argv[j], error);
if (!lb)
continue;
while ((line = Linebuf_getline(lb)) != NULL)
do_host(line);
Linebuf_free(lb);
}
}
while (optind < argc)
do_host(argv[optind++]);
while (ncon > 0)
conloop();
return (0);
}
struct sshauthopt *
sshauthopt_parse(const char *opts, const char **errstrp)
{
char **oarray, *opt, *cp, *tmp, *host;
int r;
struct sshauthopt *ret = NULL;
const char *errstr = "unknown error";
uint64_t valid_before;
if (errstrp != NULL)
*errstrp = NULL;
if ((ret = sshauthopt_new_with_keys_defaults()) == NULL)
goto alloc_fail;
if (opts == NULL)
return ret;
while (*opts && *opts != ' ' && *opts != '\t') {
/* flag options */
if ((r = opt_flag("restrict", 0, &opts)) != -1) {
ret->restricted = 1;
ret->permit_port_forwarding_flag = 0;
ret->permit_agent_forwarding_flag = 0;
ret->permit_x11_forwarding_flag = 0;
ret->permit_pty_flag = 0;
ret->permit_user_rc = 0;
} else if ((r = opt_flag("cert-authority", 0, &opts)) != -1) {
ret->cert_authority = r;
} else if ((r = opt_flag("port-forwarding", 1, &opts)) != -1) {
ret->permit_port_forwarding_flag = r == 1;
} else if ((r = opt_flag("agent-forwarding", 1, &opts)) != -1) {
ret->permit_agent_forwarding_flag = r == 1;
} else if ((r = opt_flag("x11-forwarding", 1, &opts)) != -1) {
ret->permit_x11_forwarding_flag = r == 1;
} else if ((r = opt_flag("pty", 1, &opts)) != -1) {
ret->permit_pty_flag = r == 1;
} else if ((r = opt_flag("user-rc", 1, &opts)) != -1) {
ret->permit_user_rc = r == 1;
} else if (opt_match(&opts, "command")) {
if (ret->force_command != NULL) {
errstr = "multiple \"command\" clauses";
goto fail;
}
ret->force_command = opt_dequote(&opts, &errstr);
if (ret->force_command == NULL)
goto fail;
} else if (opt_match(&opts, "principals")) {
if (ret->cert_principals != NULL) {
errstr = "multiple \"principals\" clauses";
goto fail;
}
ret->cert_principals = opt_dequote(&opts, &errstr);
if (ret->cert_principals == NULL)
goto fail;
} else if (opt_match(&opts, "from")) {
if (ret->required_from_host_keys != NULL) {
errstr = "multiple \"from\" clauses";
goto fail;
}
ret->required_from_host_keys = opt_dequote(&opts,
&errstr);
if (ret->required_from_host_keys == NULL)
goto fail;
} else if (opt_match(&opts, "expiry-time")) {
if ((opt = opt_dequote(&opts, &errstr)) == NULL)
goto fail;
if (parse_absolute_time(opt, &valid_before) != 0 ||
valid_before == 0) {
free(opt);
errstr = "invalid expires time";
goto fail;
}
free(opt);
if (ret->valid_before == 0 ||
valid_before < ret->valid_before)
ret->valid_before = valid_before;
} else if (opt_match(&opts, "environment")) {
if (ret->nenv > INT_MAX) {
errstr = "too many environment strings";
goto fail;
}
if ((opt = opt_dequote(&opts, &errstr)) == NULL)
goto fail;
/* env name must be alphanumeric and followed by '=' */
if ((tmp = strchr(opt, '=')) == NULL) {
free(opt);
errstr = "invalid environment string";
goto fail;
}
for (cp = opt; cp < tmp; cp++) {
if (!isalnum((u_char)*cp)) {
free(opt);
errstr = "invalid environment string";
goto fail;
}
}
/* Append it. */
oarray = ret->env;
if ((ret->env = recallocarray(ret->env, ret->nenv,
ret->nenv + 1, sizeof(*ret->env))) == NULL) {
free(opt);
ret->env = oarray; /* put it back for cleanup */
goto alloc_fail;
}
ret->env[ret->nenv++] = opt;
} else if (opt_match(&opts, "permitopen")) {
if (ret->npermitopen > INT_MAX) {
errstr = "too many permitopens";
goto fail;
}
if ((opt = opt_dequote(&opts, &errstr)) == NULL)
goto fail;
if ((tmp = strdup(opt)) == NULL) {
free(opt);
goto alloc_fail;
}
cp = tmp;
/* validate syntax of permitopen before recording it. */
host = hpdelim(&cp);
if (host == NULL || strlen(host) >= NI_MAXHOST) {
free(tmp);
free(opt);
errstr = "invalid permitopen hostname";
goto fail;
}
/*
* don't want to use permitopen_port to avoid
* dependency on channels.[ch] here.
*/
if (cp == NULL ||
(strcmp(cp, "*") != 0 && a2port(cp) <= 0)) {
free(tmp);
free(opt);
errstr = "invalid permitopen port";
goto fail;
}
/* XXX - add streamlocal support */
free(tmp);
/* Record it */
oarray = ret->permitopen;
if ((ret->permitopen = recallocarray(ret->permitopen,
ret->npermitopen, ret->npermitopen + 1,
sizeof(*ret->permitopen))) == NULL) {
free(opt);
ret->permitopen = oarray;
goto alloc_fail;
}
ret->permitopen[ret->npermitopen++] = opt;
} else if (opt_match(&opts, "tunnel")) {
if ((opt = opt_dequote(&opts, &errstr)) == NULL)
goto fail;
ret->force_tun_device = a2tun(opt, NULL);
free(opt);
if (ret->force_tun_device == SSH_TUNID_ERR) {
errstr = "invalid tun device";
goto fail;
}
}
/*
* Skip the comma, and move to the next option
* (or break out if there are no more).
*/
if (*opts == '\0' || *opts == ' ' || *opts == '\t')
break; /* End of options. */
/* Anything other than a comma is an unknown option */
if (*opts != ',') {
errstr = "unknown key option";
goto fail;
}
opts++;
if (*opts == '\0') {
errstr = "unexpected end-of-options";
goto fail;
}
}
/* success */
if (errstrp != NULL)
*errstrp = NULL;
return ret;
alloc_fail:
errstr = "memory allocation failed";
fail:
sshauthopt_free(ret);
if (errstrp != NULL)
*errstrp = errstr;
return NULL;
}
int
process_server_config_line(ServerOptions *options, char *line,
const char *filename, int linenum)
{
char *cp, **charptr, *arg, *p;
int *intptr, value, i, n;
ServerOpCodes opcode;
cp = line;
arg = strdelim(&cp);
/* Ignore leading whitespace */
if (*arg == '\0')
arg = strdelim(&cp);
if (!arg || !*arg || *arg == '#')
return 0;
intptr = NULL;
charptr = NULL;
opcode = parse_token(arg, filename, linenum);
switch (opcode) {
/* Portable-specific options */
case sPAMAuthenticationViaKbdInt:
intptr = &options->pam_authentication_via_kbd_int;
goto parse_flag;
/* Standard Options */
case sBadOption:
return -1;
case sPort:
/* ignore ports from configfile if cmdline specifies ports */
if (options->ports_from_cmdline)
return 0;
if (options->listen_addrs != NULL)
fatal("%s line %d: ports must be specified before "
"ListenAddress.", filename, linenum);
if (options->num_ports >= MAX_PORTS)
fatal("%s line %d: too many ports.",
filename, linenum);
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing port number.",
filename, linenum);
options->ports[options->num_ports++] = a2port(arg);
if (options->ports[options->num_ports-1] == 0)
fatal("%s line %d: Badly formatted port number.",
filename, linenum);
break;
case sServerKeyBits:
intptr = &options->server_key_bits;
parse_int:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing integer value.",
filename, linenum);
value = atoi(arg);
if (*intptr == -1)
*intptr = value;
break;
case sLoginGraceTime:
intptr = &options->login_grace_time;
parse_time:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing time value.",
filename, linenum);
if ((value = convtime(arg)) == -1)
fatal("%s line %d: invalid time value.",
filename, linenum);
if (*intptr == -1)
*intptr = value;
break;
case sKeyRegenerationTime:
intptr = &options->key_regeneration_time;
goto parse_time;
case sListenAddress:
arg = strdelim(&cp);
if (!arg || *arg == '\0' || strncmp(arg, "[]", 2) == 0)
fatal("%s line %d: missing inet addr.",
filename, linenum);
if (*arg == '[') {
if ((p = strchr(arg, ']')) == NULL)
fatal("%s line %d: bad ipv6 inet addr usage.",
filename, linenum);
arg++;
memmove(p, p+1, strlen(p+1)+1);
} else if (((p = strchr(arg, ':')) == NULL) ||
(strchr(p+1, ':') != NULL)) {
add_listen_addr(options, arg, 0);
break;
}
if (*p == ':') {
u_short port;
p++;
if (*p == '\0')
fatal("%s line %d: bad inet addr:port usage.",
filename, linenum);
else {
*(p-1) = '\0';
if ((port = a2port(p)) == 0)
fatal("%s line %d: bad port number.",
filename, linenum);
add_listen_addr(options, arg, port);
}
} else if (*p == '\0')
add_listen_addr(options, arg, 0);
else
fatal("%s line %d: bad inet addr usage.",
filename, linenum);
break;
case sHostKeyFile:
intptr = &options->num_host_key_files;
if (*intptr >= MAX_HOSTKEYS)
fatal("%s line %d: too many host keys specified (max %d).",
filename, linenum, MAX_HOSTKEYS);
charptr = &options->host_key_files[*intptr];
parse_filename:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing file name.",
filename, linenum);
if (*charptr == NULL) {
*charptr = tilde_expand_filename(arg, getuid());
/* increase optional counter */
if (intptr != NULL)
*intptr = *intptr + 1;
}
break;
case sPidFile:
charptr = &options->pid_file;
goto parse_filename;
case sPermitRootLogin:
intptr = &options->permit_root_login;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/"
"without-password/forced-commands-only/no "
"argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "without-password") == 0)
value = PERMIT_NO_PASSWD;
else if (strcmp(arg, "forced-commands-only") == 0)
value = PERMIT_FORCED_ONLY;
else if (strcmp(arg, "yes") == 0)
value = PERMIT_YES;
else if (strcmp(arg, "no") == 0)
value = PERMIT_NO;
else
fatal("%s line %d: Bad yes/"
"without-password/forced-commands-only/no "
"argument: %s", filename, linenum, arg);
if (*intptr == -1)
*intptr = value;
break;
case sIgnoreRhosts:
intptr = &options->ignore_rhosts;
parse_flag:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/no argument.",
filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "yes") == 0)
value = 1;
else if (strcmp(arg, "no") == 0)
value = 0;
else
fatal("%s line %d: Bad yes/no argument: %s",
filename, linenum, arg);
if (*intptr == -1)
*intptr = value;
break;
case sIgnoreUserKnownHosts:
intptr = &options->ignore_user_known_hosts;
goto parse_flag;
case sRhostsAuthentication:
intptr = &options->rhosts_authentication;
goto parse_flag;
case sRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case sHostbasedAuthentication:
intptr = &options->hostbased_authentication;
goto parse_flag;
case sHostbasedUsesNameFromPacketOnly:
intptr = &options->hostbased_uses_name_from_packet_only;
goto parse_flag;
case sRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case sPubkeyAuthentication:
intptr = &options->pubkey_authentication;
goto parse_flag;
#if defined(KRB4) || defined(KRB5)
case sKerberosAuthentication:
intptr = &options->kerberos_authentication;
goto parse_flag;
case sKerberosOrLocalPasswd:
intptr = &options->kerberos_or_local_passwd;
goto parse_flag;
case sKerberosTicketCleanup:
intptr = &options->kerberos_ticket_cleanup;
goto parse_flag;
#endif
#if defined(AFS) || defined(KRB5)
case sKerberosTgtPassing:
intptr = &options->kerberos_tgt_passing;
goto parse_flag;
#endif
#ifdef AFS
case sAFSTokenPassing:
intptr = &options->afs_token_passing;
goto parse_flag;
#endif
case sPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case sKbdInteractiveAuthentication:
intptr = &options->kbd_interactive_authentication;
goto parse_flag;
case sChallengeResponseAuthentication:
intptr = &options->challenge_response_authentication;
goto parse_flag;
case sPrintMotd:
intptr = &options->print_motd;
goto parse_flag;
case sPrintLastLog:
intptr = &options->print_lastlog;
goto parse_flag;
case sX11Forwarding:
intptr = &options->x11_forwarding;
goto parse_flag;
case sX11DisplayOffset:
intptr = &options->x11_display_offset;
goto parse_int;
case sX11UseLocalhost:
intptr = &options->x11_use_localhost;
goto parse_flag;
case sXAuthLocation:
charptr = &options->xauth_location;
goto parse_filename;
case sStrictModes:
intptr = &options->strict_modes;
goto parse_flag;
case sKeepAlives:
intptr = &options->keepalives;
goto parse_flag;
case sEmptyPasswd:
intptr = &options->permit_empty_passwd;
goto parse_flag;
case sPermitUserEnvironment:
intptr = &options->permit_user_env;
goto parse_flag;
case sUseLogin:
intptr = &options->use_login;
goto parse_flag;
case sCompression:
intptr = &options->compression;
goto parse_flag;
case sGatewayPorts:
intptr = &options->gateway_ports;
goto parse_flag;
case sVerifyReverseMapping:
intptr = &options->verify_reverse_mapping;
goto parse_flag;
case sLogFacility:
intptr = (int *) &options->log_facility;
arg = strdelim(&cp);
value = log_facility_number(arg);
if (value == SYSLOG_FACILITY_NOT_SET)
fatal("%.200s line %d: unsupported log facility '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*intptr == -1)
*intptr = (SyslogFacility) value;
break;
case sLogLevel:
intptr = (int *) &options->log_level;
arg = strdelim(&cp);
value = log_level_number(arg);
if (value == SYSLOG_LEVEL_NOT_SET)
fatal("%.200s line %d: unsupported log level '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*intptr == -1)
*intptr = (LogLevel) value;
break;
case sAllowTcpForwarding:
intptr = &options->allow_tcp_forwarding;
goto parse_flag;
case sUsePrivilegeSeparation:
intptr = &use_privsep;
goto parse_flag;
case sAllowUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_allow_users >= MAX_ALLOW_USERS)
fatal("%s line %d: too many allow users.",
filename, linenum);
options->allow_users[options->num_allow_users++] =
xstrdup(arg);
}
break;
case sDenyUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_deny_users >= MAX_DENY_USERS)
fatal( "%s line %d: too many deny users.",
filename, linenum);
options->deny_users[options->num_deny_users++] =
xstrdup(arg);
}
break;
case sAllowGroups:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_allow_groups >= MAX_ALLOW_GROUPS)
fatal("%s line %d: too many allow groups.",
filename, linenum);
options->allow_groups[options->num_allow_groups++] =
xstrdup(arg);
}
break;
case sDenyGroups:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_deny_groups >= MAX_DENY_GROUPS)
fatal("%s line %d: too many deny groups.",
filename, linenum);
options->deny_groups[options->num_deny_groups++] = xstrdup(arg);
}
break;
case sCiphers:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(arg))
fatal("%s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (options->ciphers == NULL)
options->ciphers = xstrdup(arg);
break;
case sMacs:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
if (!mac_valid(arg))
fatal("%s line %d: Bad SSH2 mac spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (options->macs == NULL)
options->macs = xstrdup(arg);
break;
case sProtocol:
intptr = &options->protocol;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
value = proto_spec(arg);
if (value == SSH_PROTO_UNKNOWN)
fatal("%s line %d: Bad protocol spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
case sSubsystem:
if (options->num_subsystems >= MAX_SUBSYSTEMS) {
fatal("%s line %d: too many subsystems defined.",
filename, linenum);
}
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing subsystem name.",
filename, linenum);
for (i = 0; i < options->num_subsystems; i++)
if (strcmp(arg, options->subsystem_name[i]) == 0)
fatal("%s line %d: Subsystem '%s' already defined.",
filename, linenum, arg);
options->subsystem_name[options->num_subsystems] = xstrdup(arg);
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing subsystem command.",
filename, linenum);
options->subsystem_command[options->num_subsystems] = xstrdup(arg);
options->num_subsystems++;
break;
case sMaxStartups:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing MaxStartups spec.",
filename, linenum);
if ((n = sscanf(arg, "%d:%d:%d",
&options->max_startups_begin,
&options->max_startups_rate,
&options->max_startups)) == 3) {
if (options->max_startups_begin >
options->max_startups ||
options->max_startups_rate > 100 ||
options->max_startups_rate < 1)
fatal("%s line %d: Illegal MaxStartups spec.",
filename, linenum);
} else if (n != 1)
fatal("%s line %d: Illegal MaxStartups spec.",
filename, linenum);
else
options->max_startups = options->max_startups_begin;
break;
case sBanner:
charptr = &options->banner;
goto parse_filename;
/*
* These options can contain %X options expanded at
* connect time, so that you can specify paths like:
*
* AuthorizedKeysFile /etc/ssh_keys/%u
*/
case sAuthorizedKeysFile:
case sAuthorizedKeysFile2:
charptr = (opcode == sAuthorizedKeysFile ) ?
&options->authorized_keys_file :
&options->authorized_keys_file2;
goto parse_filename;
case sClientAliveInterval:
intptr = &options->client_alive_interval;
goto parse_time;
case sClientAliveCountMax:
intptr = &options->client_alive_count_max;
goto parse_int;
case sDeprecated:
log("%s line %d: Deprecated option %s",
filename, linenum, arg);
while (arg)
arg = strdelim(&cp);
break;
default:
fatal("%s line %d: Missing handler for opcode %s (%d)",
filename, linenum, arg, opcode);
}
if ((arg = strdelim(&cp)) != NULL && *arg != '\0')
fatal("%s line %d: garbage at end of line; \"%.200s\".",
filename, linenum, arg);
return 0;
}
/*
* parse_forward
* parses a string containing a port forwarding specification of the form:
* dynamicfwd == 0
* [listenhost:]listenport:connecthost:connectport
* dynamicfwd == 1
* [listenhost:]listenport
* returns number of arguments parsed or zero on error
*/
int
parse_forward(Forward *fwd, const char *fwdspec, int dynamicfwd, int remotefwd)
{
int i;
char *p, *cp, *fwdarg[4];
memset(fwd, '\0', sizeof(*fwd));
cp = p = xstrdup(fwdspec);
/* skip leading spaces */
while (isspace(*cp))
cp++;
for (i = 0; i < 4; ++i)
if ((fwdarg[i] = hpdelim(&cp)) == NULL)
break;
/* Check for trailing garbage */
if (cp != NULL)
i = 0; /* failure */
switch (i) {
case 1:
fwd->listen_host = NULL;
fwd->listen_port = a2port(fwdarg[0]);
fwd->connect_host = xstrdup("socks");
break;
case 2:
fwd->listen_host = xstrdup(cleanhostname(fwdarg[0]));
fwd->listen_port = a2port(fwdarg[1]);
fwd->connect_host = xstrdup("socks");
break;
case 3:
fwd->listen_host = NULL;
fwd->listen_port = a2port(fwdarg[0]);
fwd->connect_host = xstrdup(cleanhostname(fwdarg[1]));
fwd->connect_port = a2port(fwdarg[2]);
break;
case 4:
fwd->listen_host = xstrdup(cleanhostname(fwdarg[0]));
fwd->listen_port = a2port(fwdarg[1]);
fwd->connect_host = xstrdup(cleanhostname(fwdarg[2]));
fwd->connect_port = a2port(fwdarg[3]);
break;
default:
i = 0; /* failure */
}
xfree(p);
if (dynamicfwd) {
if (!(i == 1 || i == 2))
goto fail_free;
} else {
if (!(i == 3 || i == 4))
goto fail_free;
if (fwd->connect_port <= 0)
goto fail_free;
}
if (fwd->listen_port < 0 || (!remotefwd && fwd->listen_port == 0))
goto fail_free;
if (fwd->connect_host != NULL &&
strlen(fwd->connect_host) >= NI_MAXHOST)
goto fail_free;
if (fwd->listen_host != NULL &&
strlen(fwd->listen_host) >= NI_MAXHOST)
goto fail_free;
return (i);
fail_free:
if (fwd->connect_host != NULL) {
xfree(fwd->connect_host);
fwd->connect_host = NULL;
}
if (fwd->listen_host != NULL) {
xfree(fwd->listen_host);
fwd->listen_host = NULL;
}
return (0);
}
int
process_server_config_line(ServerOptions *options, char *line,
const char *filename, int linenum, int *activep, const char *user,
const char *host, const char *address)
{
char *cp, **charptr, *arg, *p;
int cmdline = 0, *intptr, value, n;
SyslogFacility *log_facility_ptr;
LogLevel *log_level_ptr;
ServerOpCodes opcode;
int port;
u_int i, flags = 0;
size_t len;
cp = line;
if ((arg = strdelim(&cp)) == NULL)
return 0;
/* Ignore leading whitespace */
if (*arg == '\0')
arg = strdelim(&cp);
if (!arg || !*arg || *arg == '#')
return 0;
intptr = NULL;
charptr = NULL;
opcode = parse_token(arg, filename, linenum, &flags);
if (activep == NULL) { /* We are processing a command line directive */
cmdline = 1;
activep = &cmdline;
}
if (*activep && opcode != sMatch)
debug3("%s:%d setting %s %s", filename, linenum, arg, cp);
if (*activep == 0 && !(flags & SSHCFG_MATCH)) {
if (user == NULL) {
fatal("%s line %d: Directive '%s' is not allowed "
"within a Match block", filename, linenum, arg);
} else { /* this is a directive we have already processed */
while (arg)
arg = strdelim(&cp);
return 0;
}
}
switch (opcode) {
/* Portable-specific options */
case sUsePAM:
intptr = &options->use_pam;
goto parse_flag;
/* Standard Options */
case sBadOption:
return -1;
case sPort:
/* ignore ports from configfile if cmdline specifies ports */
if (options->ports_from_cmdline)
return 0;
if (options->listen_addrs != NULL)
fatal("%s line %d: ports must be specified before "
"ListenAddress.", filename, linenum);
if (options->num_ports >= MAX_PORTS)
fatal("%s line %d: too many ports.",
filename, linenum);
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing port number.",
filename, linenum);
options->ports[options->num_ports++] = a2port(arg);
if (options->ports[options->num_ports-1] <= 0)
fatal("%s line %d: Badly formatted port number.",
filename, linenum);
break;
case sServerKeyBits:
intptr = &options->server_key_bits;
parse_int:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing integer value.",
filename, linenum);
value = atoi(arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case sLoginGraceTime:
intptr = &options->login_grace_time;
parse_time:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing time value.",
filename, linenum);
if ((value = convtime(arg)) == -1)
fatal("%s line %d: invalid time value.",
filename, linenum);
if (*intptr == -1)
*intptr = value;
break;
case sKeyRegenerationTime:
intptr = &options->key_regeneration_time;
goto parse_time;
case sListenAddress:
arg = strdelim(&cp);
if (arg == NULL || *arg == '\0')
fatal("%s line %d: missing address",
filename, linenum);
/* check for bare IPv6 address: no "[]" and 2 or more ":" */
if (strchr(arg, '[') == NULL && (p = strchr(arg, ':')) != NULL
&& strchr(p+1, ':') != NULL) {
add_listen_addr(options, arg, 0);
break;
}
p = hpdelim(&arg);
if (p == NULL)
fatal("%s line %d: bad address:port usage",
filename, linenum);
p = cleanhostname(p);
if (arg == NULL)
port = 0;
else if ((port = a2port(arg)) <= 0)
fatal("%s line %d: bad port number", filename, linenum);
add_listen_addr(options, p, port);
break;
case sAddressFamily:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing address family.",
filename, linenum);
intptr = &options->address_family;
if (options->listen_addrs != NULL)
fatal("%s line %d: address family must be specified before "
"ListenAddress.", filename, linenum);
if (strcasecmp(arg, "inet") == 0)
value = AF_INET;
else if (strcasecmp(arg, "inet6") == 0)
value = AF_INET6;
else if (strcasecmp(arg, "any") == 0)
value = AF_UNSPEC;
else
fatal("%s line %d: unsupported address family \"%s\".",
filename, linenum, arg);
if (*intptr == -1)
*intptr = value;
break;
case sHostKeyFile:
intptr = &options->num_host_key_files;
if (*intptr >= MAX_HOSTKEYS)
fatal("%s line %d: too many host keys specified (max %d).",
filename, linenum, MAX_HOSTKEYS);
charptr = &options->host_key_files[*intptr];
parse_filename:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing file name.",
filename, linenum);
if (*activep && *charptr == NULL) {
*charptr = tilde_expand_filename(arg, getuid());
/* increase optional counter */
if (intptr != NULL)
*intptr = *intptr + 1;
}
break;
case sPidFile:
charptr = &options->pid_file;
goto parse_filename;
case sPermitRootLogin:
intptr = &options->permit_root_login;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/"
"without-password/forced-commands-only/no "
"argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "without-password") == 0)
value = PERMIT_NO_PASSWD;
else if (strcmp(arg, "forced-commands-only") == 0)
value = PERMIT_FORCED_ONLY;
else if (strcmp(arg, "yes") == 0)
value = PERMIT_YES;
else if (strcmp(arg, "no") == 0)
value = PERMIT_NO;
else
fatal("%s line %d: Bad yes/"
"without-password/forced-commands-only/no "
"argument: %s", filename, linenum, arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case sIgnoreRhosts:
intptr = &options->ignore_rhosts;
parse_flag:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/no argument.",
filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "yes") == 0)
value = 1;
else if (strcmp(arg, "no") == 0)
value = 0;
else
fatal("%s line %d: Bad yes/no argument: %s",
filename, linenum, arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case sIgnoreUserKnownHosts:
intptr = &options->ignore_user_known_hosts;
goto parse_flag;
case sRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case sHostbasedAuthentication:
intptr = &options->hostbased_authentication;
goto parse_flag;
case sHostbasedUsesNameFromPacketOnly:
intptr = &options->hostbased_uses_name_from_packet_only;
goto parse_flag;
case sRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case sPubkeyAuthentication:
intptr = &options->pubkey_authentication;
goto parse_flag;
case sKerberosAuthentication:
intptr = &options->kerberos_authentication;
goto parse_flag;
case sKerberosOrLocalPasswd:
intptr = &options->kerberos_or_local_passwd;
goto parse_flag;
case sKerberosTicketCleanup:
intptr = &options->kerberos_ticket_cleanup;
goto parse_flag;
case sKerberosGetAFSToken:
intptr = &options->kerberos_get_afs_token;
goto parse_flag;
case sGssAuthentication:
intptr = &options->gss_authentication;
goto parse_flag;
case sGssKeyEx:
intptr = &options->gss_keyex;
goto parse_flag;
case sGssCleanupCreds:
intptr = &options->gss_cleanup_creds;
goto parse_flag;
case sGssStrictAcceptor:
intptr = &options->gss_strict_acceptor;
goto parse_flag;
case sGssStoreRekey:
intptr = &options->gss_store_rekey;
goto parse_flag;
case sPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case sZeroKnowledgePasswordAuthentication:
intptr = &options->zero_knowledge_password_authentication;
goto parse_flag;
case sKbdInteractiveAuthentication:
intptr = &options->kbd_interactive_authentication;
goto parse_flag;
case sChallengeResponseAuthentication:
intptr = &options->challenge_response_authentication;
goto parse_flag;
case sPrintMotd:
intptr = &options->print_motd;
goto parse_flag;
case sPrintLastLog:
intptr = &options->print_lastlog;
goto parse_flag;
case sX11Forwarding:
intptr = &options->x11_forwarding;
goto parse_flag;
case sX11DisplayOffset:
intptr = &options->x11_display_offset;
goto parse_int;
case sX11UseLocalhost:
intptr = &options->x11_use_localhost;
goto parse_flag;
case sXAuthLocation:
charptr = &options->xauth_location;
goto parse_filename;
case sStrictModes:
intptr = &options->strict_modes;
goto parse_flag;
case sTCPKeepAlive:
intptr = &options->tcp_keep_alive;
goto parse_flag;
case sEmptyPasswd:
intptr = &options->permit_empty_passwd;
goto parse_flag;
case sPermitUserEnvironment:
intptr = &options->permit_user_env;
goto parse_flag;
case sUseLogin:
intptr = &options->use_login;
goto parse_flag;
case sCompression:
intptr = &options->compression;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/no/delayed "
"argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "delayed") == 0)
value = COMP_DELAYED;
else if (strcmp(arg, "yes") == 0)
value = COMP_ZLIB;
else if (strcmp(arg, "no") == 0)
value = COMP_NONE;
else
fatal("%s line %d: Bad yes/no/delayed "
"argument: %s", filename, linenum, arg);
if (*intptr == -1)
*intptr = value;
break;
case sGatewayPorts:
intptr = &options->gateway_ports;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing yes/no/clientspecified "
"argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcmp(arg, "clientspecified") == 0)
value = 2;
else if (strcmp(arg, "yes") == 0)
value = 1;
else if (strcmp(arg, "no") == 0)
value = 0;
else
fatal("%s line %d: Bad yes/no/clientspecified "
"argument: %s", filename, linenum, arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
case sUseDNS:
intptr = &options->use_dns;
goto parse_flag;
case sLogFacility:
log_facility_ptr = &options->log_facility;
arg = strdelim(&cp);
value = log_facility_number(arg);
if (value == SYSLOG_FACILITY_NOT_SET)
fatal("%.200s line %d: unsupported log facility '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*log_facility_ptr == -1)
*log_facility_ptr = (SyslogFacility) value;
break;
case sLogLevel:
log_level_ptr = &options->log_level;
arg = strdelim(&cp);
value = log_level_number(arg);
if (value == SYSLOG_LEVEL_NOT_SET)
fatal("%.200s line %d: unsupported log level '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*log_level_ptr == -1)
*log_level_ptr = (LogLevel) value;
break;
case sAllowTcpForwarding:
intptr = &options->allow_tcp_forwarding;
goto parse_flag;
case sAllowAgentForwarding:
intptr = &options->allow_agent_forwarding;
goto parse_flag;
case sUsePrivilegeSeparation:
intptr = &use_privsep;
goto parse_flag;
case sAllowUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_allow_users >= MAX_ALLOW_USERS)
fatal("%s line %d: too many allow users.",
filename, linenum);
options->allow_users[options->num_allow_users++] =
xstrdup(arg);
}
break;
case sDenyUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_deny_users >= MAX_DENY_USERS)
fatal("%s line %d: too many deny users.",
filename, linenum);
options->deny_users[options->num_deny_users++] =
xstrdup(arg);
}
break;
case sAllowGroups:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_allow_groups >= MAX_ALLOW_GROUPS)
fatal("%s line %d: too many allow groups.",
filename, linenum);
options->allow_groups[options->num_allow_groups++] =
xstrdup(arg);
}
break;
case sDenyGroups:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_deny_groups >= MAX_DENY_GROUPS)
fatal("%s line %d: too many deny groups.",
filename, linenum);
options->deny_groups[options->num_deny_groups++] = xstrdup(arg);
}
break;
case sCiphers:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(arg))
fatal("%s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (options->ciphers == NULL)
options->ciphers = xstrdup(arg);
break;
case sMacs:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
if (!mac_valid(arg))
fatal("%s line %d: Bad SSH2 mac spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (options->macs == NULL)
options->macs = xstrdup(arg);
break;
case sProtocol:
intptr = &options->protocol;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
value = proto_spec(arg);
if (value == SSH_PROTO_UNKNOWN)
fatal("%s line %d: Bad protocol spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
case sSubsystem:
if (options->num_subsystems >= MAX_SUBSYSTEMS) {
fatal("%s line %d: too many subsystems defined.",
filename, linenum);
}
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing subsystem name.",
filename, linenum);
if (!*activep) {
arg = strdelim(&cp);
break;
}
for (i = 0; i < options->num_subsystems; i++)
if (strcmp(arg, options->subsystem_name[i]) == 0)
fatal("%s line %d: Subsystem '%s' already defined.",
filename, linenum, arg);
options->subsystem_name[options->num_subsystems] = xstrdup(arg);
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing subsystem command.",
filename, linenum);
options->subsystem_command[options->num_subsystems] = xstrdup(arg);
/* Collect arguments (separate to executable) */
p = xstrdup(arg);
len = strlen(p) + 1;
while ((arg = strdelim(&cp)) != NULL && *arg != '\0') {
len += 1 + strlen(arg);
p = xrealloc(p, 1, len);
strlcat(p, " ", len);
strlcat(p, arg, len);
}
options->subsystem_args[options->num_subsystems] = p;
options->num_subsystems++;
break;
case sMaxStartups:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing MaxStartups spec.",
filename, linenum);
if ((n = sscanf(arg, "%d:%d:%d",
&options->max_startups_begin,
&options->max_startups_rate,
&options->max_startups)) == 3) {
if (options->max_startups_begin >
options->max_startups ||
options->max_startups_rate > 100 ||
options->max_startups_rate < 1)
fatal("%s line %d: Illegal MaxStartups spec.",
filename, linenum);
} else if (n != 1)
fatal("%s line %d: Illegal MaxStartups spec.",
filename, linenum);
else
options->max_startups = options->max_startups_begin;
break;
case sMaxAuthTries:
intptr = &options->max_authtries;
goto parse_int;
case sMaxSessions:
intptr = &options->max_sessions;
goto parse_int;
case sBanner:
charptr = &options->banner;
goto parse_filename;
/*
* These options can contain %X options expanded at
* connect time, so that you can specify paths like:
*
* AuthorizedKeysFile /etc/ssh_keys/%u
*/
case sAuthorizedKeysFile:
case sAuthorizedKeysFile2:
charptr = (opcode == sAuthorizedKeysFile) ?
&options->authorized_keys_file :
&options->authorized_keys_file2;
goto parse_filename;
case sClientAliveInterval:
intptr = &options->client_alive_interval;
goto parse_time;
case sClientAliveCountMax:
intptr = &options->client_alive_count_max;
goto parse_int;
case sAcceptEnv:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (strchr(arg, '=') != NULL)
fatal("%s line %d: Invalid environment name.",
filename, linenum);
if (options->num_accept_env >= MAX_ACCEPT_ENV)
fatal("%s line %d: too many allow env.",
filename, linenum);
if (!*activep)
break;
options->accept_env[options->num_accept_env++] =
xstrdup(arg);
}
break;
case sPermitTunnel:
intptr = &options->permit_tun;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing yes/point-to-point/"
"ethernet/no argument.", filename, linenum);
value = -1;
for (i = 0; tunmode_desc[i].val != -1; i++)
if (strcmp(tunmode_desc[i].text, arg) == 0) {
value = tunmode_desc[i].val;
break;
}
if (value == -1)
fatal("%s line %d: Bad yes/point-to-point/ethernet/"
"no argument: %s", filename, linenum, arg);
if (*intptr == -1)
*intptr = value;
break;
case sMatch:
if (cmdline)
fatal("Match directive not supported as a command-line "
"option");
value = match_cfg_line(&cp, linenum, user, host, address);
if (value < 0)
fatal("%s line %d: Bad Match condition", filename,
linenum);
*activep = value;
break;
case sPermitOpen:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing PermitOpen specification",
filename, linenum);
n = options->num_permitted_opens; /* modified later */
if (strcmp(arg, "any") == 0) {
if (*activep && n == -1) {
channel_clear_adm_permitted_opens();
options->num_permitted_opens = 0;
}
break;
}
if (*activep && n == -1)
channel_clear_adm_permitted_opens();
for (; arg != NULL && *arg != '\0'; arg = strdelim(&cp)) {
p = hpdelim(&arg);
if (p == NULL)
fatal("%s line %d: missing host in PermitOpen",
filename, linenum);
p = cleanhostname(p);
if (arg == NULL || (port = a2port(arg)) <= 0)
fatal("%s line %d: bad port number in "
"PermitOpen", filename, linenum);
if (*activep && n == -1)
options->num_permitted_opens =
channel_add_adm_permitted_opens(p, port);
}
break;
case sForceCommand:
if (cp == NULL)
fatal("%.200s line %d: Missing argument.", filename,
linenum);
len = strspn(cp, WHITESPACE);
if (*activep && options->adm_forced_command == NULL)
options->adm_forced_command = xstrdup(cp + len);
return 0;
case sChrootDirectory:
charptr = &options->chroot_directory;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing file name.",
filename, linenum);
if (*activep && *charptr == NULL)
*charptr = xstrdup(arg);
break;
case sDeprecated:
logit("%s line %d: Deprecated option %s",
filename, linenum, arg);
while (arg)
arg = strdelim(&cp);
break;
case sUnsupported:
logit("%s line %d: Unsupported option %s",
filename, linenum, arg);
while (arg)
arg = strdelim(&cp);
break;
default:
fatal("%s line %d: Missing handler for opcode %s (%d)",
filename, linenum, arg, opcode);
}
if ((arg = strdelim(&cp)) != NULL && *arg != '\0')
fatal("%s line %d: garbage at end of line; \"%.200s\".",
filename, linenum, arg);
return 0;
}
/*
* Main program for the ssh client.
*/
int
main(int ac, char **av)
{
int i, r, opt, exit_status, use_syslog;
char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg;
char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
struct stat st;
struct passwd *pw;
int dummy, timeout_ms;
extern int optind, optreset;
extern char *optarg;
struct servent *sp;
Forward fwd;
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
__progname = ssh_get_progname(av[0]);
#ifndef HAVE_SETPROCTITLE
/* Prepare for later setproctitle emulation */
/* Save argv so it isn't clobbered by setproctitle() emulation */
saved_av = xcalloc(ac + 1, sizeof(*saved_av));
for (i = 0; i < ac; i++)
saved_av[i] = xstrdup(av[i]);
saved_av[i] = NULL;
compat_init_setproctitle(ac, av);
av = saved_av;
#endif
/*
* Discard other fds that are hanging around. These can cause problem
* with backgrounded ssh processes started by ControlPersist.
*/
closefrom(STDERR_FILENO + 1);
/*
* 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();
/*
* 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).
*/
PRIV_END;
#ifdef HAVE_SETRLIMIT
/* 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));
}
#endif
/* Get user data. */
pw = getpwuid(original_real_uid);
if (!pw) {
logit("You don't exist, go away!");
exit(255);
}
/* Take a copy of the returned structure. */
pw = pwcopy(pw);
/*
* 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);
/*
* Initialize option structure to indicate that no values have been
* set.
*/
initialize_options(&options);
/* Parse command-line arguments. */
host = NULL;
use_syslog = 0;
argv0 = av[0];
again:
while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
"ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
switch (opt) {
case '1':
options.protocol = SSH_PROTO_1;
break;
case '2':
options.protocol = SSH_PROTO_2;
break;
case '4':
options.address_family = AF_INET;
break;
case '6':
options.address_family = 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 'y':
use_syslog = 1;
break;
case 'Y':
options.forward_x11 = 1;
options.forward_x11_trusted = 1;
break;
case 'g':
options.gateway_ports = 1;
break;
case 'O':
if (stdio_forward_host != NULL)
fatal("Cannot specify multiplexing "
"command with -W");
else if (muxclient_command != 0)
fatal("Multiplexing command already specified");
if (strcmp(optarg, "check") == 0)
muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
else if (strcmp(optarg, "forward") == 0)
muxclient_command = SSHMUX_COMMAND_FORWARD;
else if (strcmp(optarg, "exit") == 0)
muxclient_command = SSHMUX_COMMAND_TERMINATE;
else if (strcmp(optarg, "stop") == 0)
muxclient_command = SSHMUX_COMMAND_STOP;
else if (strcmp(optarg, "cancel") == 0)
muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
else
fatal("Invalid multiplex command.");
break;
case 'P': /* deprecated */
options.use_privileged_port = 0;
break;
case 'a':
options.forward_agent = 0;
break;
case 'A':
options.forward_agent = 1;
break;
case 'k':
options.gss_deleg_creds = 0;
break;
case 'K':
options.gss_authentication = 1;
options.gss_deleg_creds = 1;
break;
case 'i':
if (stat(optarg, &st) < 0) {
fprintf(stderr, "Warning: Identity file %s "
"not accessible: %s.\n", optarg,
strerror(errno));
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 'I':
#ifdef ENABLE_PKCS11
options.pkcs11_provider = xstrdup(optarg);
#else
fprintf(stderr, "no support for PKCS#11.\n");
#endif
break;
case 't':
if (options.request_tty == REQUEST_TTY_YES)
options.request_tty = REQUEST_TTY_FORCE;
else
options.request_tty = REQUEST_TTY_YES;
break;
case 'v':
if (debug_flag == 0) {
debug_flag = 1;
options.log_level = SYSLOG_LEVEL_DEBUG1;
} else {
if (options.log_level < SYSLOG_LEVEL_DEBUG3)
options.log_level++;
break;
}
/* FALLTHROUGH */
case 'V':
fprintf(stderr, "%s, %s\n",
SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
if (opt == 'V')
exit(0);
break;
case 'w':
if (options.tun_open == -1)
options.tun_open = SSH_TUNMODE_DEFAULT;
options.tun_local = a2tun(optarg, &options.tun_remote);
if (options.tun_local == SSH_TUNID_ERR) {
fprintf(stderr,
"Bad tun device '%s'\n", optarg);
exit(255);
}
break;
case 'W':
if (stdio_forward_host != NULL)
fatal("stdio forward already specified");
if (muxclient_command != 0)
fatal("Cannot specify stdio forward with -O");
if (parse_forward(&fwd, optarg, 1, 0)) {
stdio_forward_host = fwd.listen_host;
stdio_forward_port = fwd.listen_port;
xfree(fwd.connect_host);
} else {
fprintf(stderr,
"Bad stdio forwarding specification '%s'\n",
optarg);
exit(255);
}
options.request_tty = REQUEST_TTY_NO;
no_shell_flag = 1;
options.clear_forwardings = 1;
options.exit_on_forward_failure = 1;
break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
break;
case 'e':
if (optarg[0] == '^' && optarg[2] == 0 &&
(u_char) optarg[1] >= 64 &&
(u_char) optarg[1] < 128)
options.escape_char = (u_char) optarg[1] & 31;
else if (strlen(optarg) == 1)
options.escape_char = (u_char) optarg[0];
else if (strcmp(optarg, "none") == 0)
options.escape_char = SSH_ESCAPECHAR_NONE;
else {
fprintf(stderr, "Bad escape character '%s'.\n",
optarg);
exit(255);
}
break;
case 'c':
if (ciphers_valid(optarg)) {
/* SSH2 only */
options.ciphers = xstrdup(optarg);
options.cipher = SSH_CIPHER_INVALID;
} else {
/* SSH1 only */
options.cipher = cipher_number(optarg);
if (options.cipher == -1) {
fprintf(stderr,
"Unknown cipher type '%s'\n",
optarg);
exit(255);
}
if (options.cipher == SSH_CIPHER_3DES)
options.ciphers = "3des-cbc";
else if (options.cipher == SSH_CIPHER_BLOWFISH)
options.ciphers = "blowfish-cbc";
else
options.ciphers = (char *)-1;
}
break;
case 'm':
if (mac_valid(optarg))
options.macs = xstrdup(optarg);
else {
fprintf(stderr, "Unknown mac type '%s'\n",
optarg);
exit(255);
}
break;
case 'M':
if (options.control_master == SSHCTL_MASTER_YES)
options.control_master = SSHCTL_MASTER_ASK;
else
options.control_master = SSHCTL_MASTER_YES;
break;
case 'p':
options.port = a2port(optarg);
if (options.port <= 0) {
fprintf(stderr, "Bad port '%s'\n", optarg);
exit(255);
}
break;
case 'l':
options.user = optarg;
break;
case 'L':
if (parse_forward(&fwd, optarg, 0, 0))
add_local_forward(&options, &fwd);
else {
fprintf(stderr,
"Bad local forwarding specification '%s'\n",
optarg);
exit(255);
}
break;
case 'R':
if (parse_forward(&fwd, optarg, 0, 1)) {
add_remote_forward(&options, &fwd);
} else {
fprintf(stderr,
"Bad remote forwarding specification "
"'%s'\n", optarg);
exit(255);
}
break;
case 'D':
if (parse_forward(&fwd, optarg, 1, 0)) {
add_local_forward(&options, &fwd);
} else {
fprintf(stderr,
"Bad dynamic forwarding specification "
"'%s'\n", optarg);
exit(255);
}
break;
case 'C':
options.compression = 1;
break;
case 'N':
no_shell_flag = 1;
options.request_tty = REQUEST_TTY_NO;
break;
case 'T':
options.request_tty = REQUEST_TTY_NO;
break;
case 'o':
dummy = 1;
line = xstrdup(optarg);
if (process_config_line(&options, host ? host : "",
line, "command-line", 0, &dummy) != 0)
exit(255);
xfree(line);
break;
case 's':
subsystem_flag = 1;
break;
case 'S':
if (options.control_path != NULL)
free(options.control_path);
options.control_path = xstrdup(optarg);
break;
case 'b':
options.bind_address = optarg;
break;
case 'F':
config = optarg;
break;
default:
usage();
}
}
ac -= optind;
av += optind;
if (ac > 0 && !host) {
if (strrchr(*av, '@')) {
p = xstrdup(*av);
cp = strrchr(p, '@');
if (cp == NULL || cp == p)
usage();
options.user = p;
*cp = '\0';
host = ++cp;
} else
host = *av;
if (ac > 1) {
optind = optreset = 1;
goto again;
}
ac--, av++;
}
/* Check that we got a host name. */
if (!host)
usage();
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
/* Initialize the command to execute on remote host. */
buffer_init(&command);
if (options.request_tty == REQUEST_TTY_YES ||
options.request_tty == REQUEST_TTY_FORCE)
tty_flag = 1;
/*
* 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 (!ac) {
/* No command specified - execute shell on a tty. */
tty_flag = options.request_tty != REQUEST_TTY_NO;
if (subsystem_flag) {
fprintf(stderr,
"You must specify a subsystem to invoke.\n");
usage();
}
} else {
/* A command has been specified. Store it into the buffer. */
for (i = 0; i < ac; i++) {
if (i)
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 = options.request_tty != REQUEST_TTY_NO;
/* Force no tty */
if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0)
tty_flag = 0;
/* Do not allocate a tty if stdin is not a tty. */
if ((!isatty(fileno(stdin)) || stdin_null_flag) &&
options.request_tty != REQUEST_TTY_FORCE) {
if (tty_flag)
logit("Pseudo-terminal will not be allocated because "
"stdin is not a terminal.");
tty_flag = 0;
}
/*
* Initialize "log" output. Since we are the client all output
* actually goes to stderr.
*/
log_init(argv0,
options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
SYSLOG_FACILITY_USER, !use_syslog);
/*
* Read per-user configuration file. Ignore the system wide config
* file if the user specifies a config file on the command line.
*/
if (config != NULL) {
if (!read_config_file(config, host, &options, 0))
fatal("Can't open user config file %.100s: "
"%.100s", config, strerror(errno));
} else {
r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
_PATH_SSH_USER_CONFFILE);
if (r > 0 && (size_t)r < sizeof(buf))
(void)read_config_file(buf, host, &options, 1);
/* Read systemwide configuration file after user config. */
(void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
&options, 0);
}
/* Fill configuration defaults. */
fill_default_options(&options);
channel_set_af(options.address_family);
/* reinit */
log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
seed_rng();
if (options.user == NULL)
options.user = xstrdup(pw->pw_name);
/* Get default port if port has not been set. */
if (options.port == 0) {
sp = getservbyname(SSH_SERVICE_NAME, "tcp");
options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
}
/* preserve host name given on command line for %n expansion */
host_arg = host;
if (options.hostname != NULL) {
host = percent_expand(options.hostname,
"h", host, (char *)NULL);
}
if (gethostname(thishost, sizeof(thishost)) == -1)
fatal("gethostname: %s", strerror(errno));
strlcpy(shorthost, thishost, sizeof(shorthost));
shorthost[strcspn(thishost, ".")] = '\0';
snprintf(portstr, sizeof(portstr), "%d", options.port);
if (options.local_command != NULL) {
debug3("expanding LocalCommand: %s", options.local_command);
cp = options.local_command;
options.local_command = percent_expand(cp, "d", pw->pw_dir,
"h", host, "l", thishost, "n", host_arg, "r", options.user,
"p", portstr, "u", pw->pw_name, "L", shorthost,
(char *)NULL);
debug3("expanded LocalCommand: %s", options.local_command);
xfree(cp);
}
/* force lowercase for hostkey matching */
if (options.host_key_alias != NULL) {
for (p = options.host_key_alias; *p; p++)
if (isupper(*p))
*p = (char)tolower(*p);
}
if (options.proxy_command != NULL &&
strcmp(options.proxy_command, "none") == 0) {
xfree(options.proxy_command);
options.proxy_command = NULL;
}
if (options.control_path != NULL &&
strcmp(options.control_path, "none") == 0) {
xfree(options.control_path);
options.control_path = NULL;
}
if (options.control_path != NULL) {
cp = tilde_expand_filename(options.control_path,
original_real_uid);
xfree(options.control_path);
options.control_path = percent_expand(cp, "h", host,
"l", thishost, "n", host_arg, "r", options.user,
"p", portstr, "u", pw->pw_name, "L", shorthost,
(char *)NULL);
xfree(cp);
}
if (muxclient_command != 0 && options.control_path == NULL)
fatal("No ControlPath specified for \"-O\" command");
if (options.control_path != NULL)
muxclient(options.control_path);
timeout_ms = options.connection_timeout * 1000;
/* Open a connection to the remote host. */
if (ssh_connect(host, &hostaddr, options.port,
options.address_family, options.connection_attempts, &timeout_ms,
options.tcp_keep_alive,
#ifdef HAVE_CYGWIN
options.use_privileged_port,
#else
original_effective_uid == 0 && options.use_privileged_port,
#endif
options.proxy_command) != 0)
exit(255);
if (timeout_ms > 0)
debug3("timeout: %d ms remain after connect", timeout_ms);
/*
* 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 we cannot access the private keys, load the public keys
* instead and try to execute the ssh-keysign helper instead.
*/
sensitive_data.nkeys = 0;
sensitive_data.keys = NULL;
sensitive_data.external_keysign = 0;
if (options.rhosts_rsa_authentication ||
options.hostbased_authentication) {
sensitive_data.nkeys = 7;
sensitive_data.keys = xcalloc(sensitive_data.nkeys,
sizeof(Key));
for (i = 0; i < sensitive_data.nkeys; i++)
sensitive_data.keys[i] = NULL;
PRIV_START;
sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
_PATH_HOST_KEY_FILE, "", NULL, NULL);
sensitive_data.keys[1] = key_load_private_cert(KEY_DSA,
_PATH_HOST_DSA_KEY_FILE, "", NULL);
#ifdef OPENSSL_HAS_ECC
sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA,
_PATH_HOST_ECDSA_KEY_FILE, "", NULL);
#endif
sensitive_data.keys[3] = key_load_private_cert(KEY_RSA,
_PATH_HOST_RSA_KEY_FILE, "", NULL);
sensitive_data.keys[4] = key_load_private_type(KEY_DSA,
_PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
#ifdef OPENSSL_HAS_ECC
sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA,
_PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL);
#endif
sensitive_data.keys[6] = key_load_private_type(KEY_RSA,
_PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
PRIV_END;
if (options.hostbased_authentication == 1 &&
sensitive_data.keys[0] == NULL &&
sensitive_data.keys[4] == NULL &&
sensitive_data.keys[5] == NULL &&
sensitive_data.keys[6] == NULL) {
sensitive_data.keys[1] = key_load_cert(
_PATH_HOST_DSA_KEY_FILE);
#ifdef OPENSSL_HAS_ECC
sensitive_data.keys[2] = key_load_cert(
_PATH_HOST_ECDSA_KEY_FILE);
#endif
sensitive_data.keys[3] = key_load_cert(
_PATH_HOST_RSA_KEY_FILE);
sensitive_data.keys[4] = key_load_public(
_PATH_HOST_DSA_KEY_FILE, NULL);
#ifdef OPENSSL_HAS_ECC
sensitive_data.keys[5] = key_load_public(
_PATH_HOST_ECDSA_KEY_FILE, NULL);
#endif
sensitive_data.keys[6] = key_load_public(
_PATH_HOST_RSA_KEY_FILE, NULL);
sensitive_data.external_keysign = 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.
*/
if (original_effective_uid == 0) {
PRIV_START;
permanently_set_uid(pw);
}
/*
* Now that we are back to our own permissions, create ~/.ssh
* directory if it doesn't already exist.
*/
if (config == NULL) {
r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) {
#ifdef WITH_SELINUX
ssh_selinux_setfscreatecon(buf);
#endif
if (mkdir(buf, 0700) < 0)
error("Could not create directory '%.200s'.",
buf);
#ifdef WITH_SELINUX
ssh_selinux_setfscreatecon(NULL);
#endif
}
}
/* load options.identity_files */
load_public_identity_files();
/* Expand ~ in known host file names. */
tilde_expand_paths(options.system_hostfiles,
options.num_system_hostfiles);
tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
signal(SIGCHLD, main_sigchld_handler);
/* Log into the remote system. Never returns if the login fails. */
ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
options.port, pw, timeout_ms);
if (packet_connection_is_on_socket()) {
verbose("Authenticated to %s ([%s]:%d).", host,
get_remote_ipaddr(), get_remote_port());
} else {
verbose("Authenticated to %s (via proxy).", host);
}
/* We no longer need the private host keys. Clear them now. */
if (sensitive_data.nkeys != 0) {
for (i = 0; i < sensitive_data.nkeys; i++) {
if (sensitive_data.keys[i] != NULL) {
/* Destroys contents safely */
debug3("clear hostkey %d", i);
key_free(sensitive_data.keys[i]);
sensitive_data.keys[i] = NULL;
}
}
xfree(sensitive_data.keys);
}
for (i = 0; i < options.num_identity_files; i++) {
if (options.identity_files[i]) {
xfree(options.identity_files[i]);
options.identity_files[i] = NULL;
}
if (options.identity_keys[i]) {
key_free(options.identity_keys[i]);
options.identity_keys[i] = NULL;
}
}
exit_status = compat20 ? ssh_session2() : ssh_session();
packet_close();
if (options.control_path != NULL && muxserver_sock != -1)
unlink(options.control_path);
/* Kill ProxyCommand if it is running. */
ssh_kill_proxy_command();
return exit_status;
}
/*
* Main program for the daemon.
*/
int
main(int ac, char **av)
{
extern char *optarg;
extern int optind;
int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
pid_t pid;
socklen_t fromlen;
fd_set *fdset;
struct sockaddr_storage from;
const char *remote_ip;
int remote_port;
FILE *f;
struct linger linger;
struct addrinfo *ai;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
int listen_sock, maxfd;
int startup_p[2];
int startups = 0;
Authctxt *authctxt;
Key *key;
int ret, key_used = 0;
#ifdef HAVE_SECUREWARE
(void)set_auth_parameters(ac, av);
#endif
__progname = get_progname(av[0]);
init_rng();
/* Save argv. */
saved_argc = ac;
saved_argv = av;
/* Initialize configuration options to their default values. */
initialize_server_options(&options);
/* Parse command-line arguments. */
while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:o:dDeiqtQ46:S")) != -1) {
switch (opt) {
case '4':
IPv4or6 = AF_INET;
break;
case '6':
IPv4or6 = AF_INET6;
break;
case 'f':
config_file_name = optarg;
break;
case 'd':
if (0 == debug_flag) {
debug_flag = 1;
options.log_level = SYSLOG_LEVEL_DEBUG1;
} else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
options.log_level++;
} else {
fprintf(stderr, "Too high debugging level.\n");
exit(1);
}
break;
case 'D':
no_daemon_flag = 1;
break;
case 'e':
log_stderr = 1;
break;
case 'i':
inetd_flag = 1;
break;
case 'Q':
/* ignored */
break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
break;
case 'b':
options.server_key_bits = atoi(optarg);
break;
case 'p':
options.ports_from_cmdline = 1;
if (options.num_ports >= MAX_PORTS) {
fprintf(stderr, "too many ports.\n");
exit(1);
}
options.ports[options.num_ports++] = a2port(optarg);
if (options.ports[options.num_ports-1] == 0) {
fprintf(stderr, "Bad port number.\n");
exit(1);
}
break;
case 'g':
if ((options.login_grace_time = convtime(optarg)) == -1) {
fprintf(stderr, "Invalid login grace time.\n");
exit(1);
}
break;
case 'k':
if ((options.key_regeneration_time = convtime(optarg)) == -1) {
fprintf(stderr, "Invalid key regeneration interval.\n");
exit(1);
}
break;
case 'h':
if (options.num_host_key_files >= MAX_HOSTKEYS) {
fprintf(stderr, "too many host keys.\n");
exit(1);
}
options.host_key_files[options.num_host_key_files++] = optarg;
break;
case 'V':
client_version_string = optarg;
/* only makes sense with inetd_flag, i.e. no listen() */
inetd_flag = 1;
break;
case 't':
test_flag = 1;
break;
case 'u':
utmp_len = atoi(optarg);
break;
case 'o':
if (process_server_config_line(&options, optarg,
"command-line", 0) != 0)
exit(1);
break;
case 'S':
protocol = IPPROTO_SCTP;
break;
case '?':
default:
usage();
break;
}
}
SSLeay_add_all_algorithms();
channel_set_af(IPv4or6);
/*
* Force logging to stderr until we have loaded the private host
* key (unless started from inetd)
*/
log_init(__progname,
options.log_level == SYSLOG_LEVEL_NOT_SET ?
SYSLOG_LEVEL_INFO : options.log_level,
options.log_facility == SYSLOG_FACILITY_NOT_SET ?
SYSLOG_FACILITY_AUTH : options.log_facility,
!inetd_flag);
#ifdef _CRAY
/* Cray can define user privs drop all prives now!
* Not needed on PRIV_SU systems!
*/
drop_cray_privs();
#endif
seed_rng();
/* Read server configuration options from the configuration file. */
read_server_config(&options, config_file_name);
/* Fill in default values for those options not explicitly set. */
fill_default_server_options(&options);
/* Check that there are no remaining arguments. */
if (optind < ac) {
fprintf(stderr, "Extra argument %s.\n", av[optind]);
exit(1);
}
debug("sshd version %.100s", SSH_VERSION);
/* load private host keys */
sensitive_data.host_keys = xmalloc(options.num_host_key_files*sizeof(Key*));
for (i = 0; i < options.num_host_key_files; i++)
sensitive_data.host_keys[i] = NULL;
sensitive_data.server_key = NULL;
sensitive_data.ssh1_host_key = NULL;
sensitive_data.have_ssh1_key = 0;
sensitive_data.have_ssh2_key = 0;
for (i = 0; i < options.num_host_key_files; i++) {
key = key_load_private(options.host_key_files[i], "", NULL);
sensitive_data.host_keys[i] = key;
if (key == NULL) {
error("Could not load host key: %s",
options.host_key_files[i]);
sensitive_data.host_keys[i] = NULL;
continue;
}
switch (key->type) {
case KEY_RSA1:
sensitive_data.ssh1_host_key = key;
sensitive_data.have_ssh1_key = 1;
break;
case KEY_RSA:
case KEY_DSA:
sensitive_data.have_ssh2_key = 1;
break;
}
debug("private host key: #%d type %d %s", i, key->type,
key_type(key));
}
if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
log("Disabling protocol version 1. Could not load host key");
options.protocol &= ~SSH_PROTO_1;
}
if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
log("Disabling protocol version 2. Could not load host key");
options.protocol &= ~SSH_PROTO_2;
}
if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
log("sshd: no hostkeys available -- exiting.");
exit(1);
}
/* Check certain values for sanity. */
if (options.protocol & SSH_PROTO_1) {
if (options.server_key_bits < 512 ||
options.server_key_bits > 32768) {
fprintf(stderr, "Bad server key size.\n");
exit(1);
}
/*
* Check that server and host key lengths differ sufficiently. This
* is necessary to make double encryption work with rsaref. Oh, I
* hate software patents. I dont know if this can go? Niels
*/
if (options.server_key_bits >
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
SSH_KEY_BITS_RESERVED && options.server_key_bits <
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
SSH_KEY_BITS_RESERVED) {
options.server_key_bits =
BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
SSH_KEY_BITS_RESERVED;
debug("Forcing server key to %d bits to make it differ from host key.",
options.server_key_bits);
}
}
if (use_privsep) {
struct passwd *pw;
struct stat st;
if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
fatal("Privilege separation user %s does not exist",
SSH_PRIVSEP_USER);
if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
(S_ISDIR(st.st_mode) == 0))
fatal("Missing privilege separation directory: %s",
_PATH_PRIVSEP_CHROOT_DIR);
if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
fatal("Bad owner or mode for %s",
_PATH_PRIVSEP_CHROOT_DIR);
}
/* Configuration looks good, so exit if in test mode. */
if (test_flag)
exit(0);
/*
* Clear out any supplemental groups we may have inherited. This
* prevents inadvertent creation of files with bad modes (in the
* portable version at least, it's certainly possible for PAM
* to create a file, and we can't control the code in every
* module which might be used).
*/
if (setgroups(0, NULL) < 0)
debug("setgroups() failed: %.200s", strerror(errno));
/* Initialize the log (it is reinitialized below in case we forked). */
if (debug_flag && !inetd_flag)
log_stderr = 1;
log_init(__progname, options.log_level, options.log_facility, log_stderr);
/*
* If not in debugging mode, and not started from inetd, disconnect
* from the controlling terminal, and fork. The original process
* exits.
*/
if (!(debug_flag || inetd_flag || no_daemon_flag)) {
#ifdef TIOCNOTTY
int fd;
#endif /* TIOCNOTTY */
if (daemon(0, 0) < 0)
fatal("daemon() failed: %.200s", strerror(errno));
/* Disconnect from the controlling tty. */
#ifdef TIOCNOTTY
fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
if (fd >= 0) {
(void) ioctl(fd, TIOCNOTTY, NULL);
close(fd);
}
#endif /* TIOCNOTTY */
}
/* Reinitialize the log (because of the fork above). */
log_init(__progname, options.log_level, options.log_facility, log_stderr);
/* Initialize the random number generator. */
arc4random_stir();
/* Chdir to the root directory so that the current disk can be
unmounted if desired. */
chdir("/");
/* ignore SIGPIPE */
signal(SIGPIPE, SIG_IGN);
/* Start listening for a socket, unless started from inetd. */
if (inetd_flag) {
int s1;
s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */
dup(s1);
sock_in = dup(0);
sock_out = dup(1);
startup_pipe = -1;
/*
* We intentionally do not close the descriptors 0, 1, and 2
* as our code for setting the descriptors won\'t work if
* ttyfd happens to be one of those.
*/
debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
if (options.protocol & SSH_PROTO_1)
generate_ephemeral_server_key();
} else {
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, protocol);
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,
&on, sizeof(on));
linger.l_onoff = 1;
linger.l_linger = 5;
setsockopt(listen_sock, SOL_SOCKET, SO_LINGER,
&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) {
if (!ai->ai_next)
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 (options.protocol & SSH_PROTO_1)
generate_ephemeral_server_key();
/*
* Arrange to restart on SIGHUP. The handler needs
* listen_sock.
*/
signal(SIGHUP, sighup_handler);
signal(SIGTERM, sigterm_handler);
signal(SIGQUIT, sigterm_handler);
/* Arrange SIGCHLD to be caught. */
signal(SIGCHLD, main_sigchld_handler);
/* Write out the pid file after the sigterm handler is setup */
if (!debug_flag) {
/*
* Record our pid in /var/run/sshd.pid to make it
* easier to kill the correct sshd. We don't want to
* do this before the bind above because the bind will
* fail if there already is a daemon, and this will
* overwrite any old pid in the file.
*/
f = fopen(options.pid_file, "wb");
if (f) {
fprintf(f, "%ld\n", (long) getpid());
fclose(f);
}
}
/* setup fd set for listen */
fdset = NULL;
maxfd = 0;
for (i = 0; i < num_listen_socks; i++)
if (listen_socks[i] > maxfd)
maxfd = listen_socks[i];
/* pipes connected to unauthenticated childs */
startup_pipes = xmalloc(options.max_startups * sizeof(int));
for (i = 0; i < options.max_startups; i++)
startup_pipes[i] = -1;
/*
* Stay listening for connections until the system crashes or
* the daemon is killed with a signal.
*/
for (;;) {
if (received_sighup)
sighup_restart();
if (fdset != NULL)
xfree(fdset);
fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
fdset = (fd_set *)xmalloc(fdsetsz);
memset(fdset, 0, fdsetsz);
for (i = 0; i < num_listen_socks; i++)
FD_SET(listen_socks[i], fdset);
for (i = 0; i < options.max_startups; i++)
if (startup_pipes[i] != -1)
FD_SET(startup_pipes[i], fdset);
/* Wait in select until there is a connection. */
ret = select(maxfd+1, fdset, NULL, NULL, NULL);
if (ret < 0 && errno != EINTR)
error("select: %.100s", strerror(errno));
if (received_sigterm) {
log("Received signal %d; terminating.",
(int) received_sigterm);
close_listen_socks();
unlink(options.pid_file);
exit(255);
}
if (key_used && key_do_regen) {
generate_ephemeral_server_key();
key_used = 0;
key_do_regen = 0;
}
if (ret < 0)
continue;
for (i = 0; i < options.max_startups; i++)
if (startup_pipes[i] != -1 &&
FD_ISSET(startup_pipes[i], fdset)) {
/*
* the read end of the pipe is ready
* if the child has closed the pipe
* after successful authentication
* or if the child has died
*/
close(startup_pipes[i]);
startup_pipes[i] = -1;
startups--;
}
for (i = 0; i < num_listen_socks; i++) {
if (!FD_ISSET(listen_socks[i], fdset))
continue;
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));
close(newsock);
continue;
}
if (drop_connection(startups) == 1) {
debug("drop connection #%d", startups);
close(newsock);
continue;
}
if (pipe(startup_p) == -1) {
close(newsock);
continue;
}
for (j = 0; j < options.max_startups; j++)
if (startup_pipes[j] == -1) {
startup_pipes[j] = startup_p[0];
if (maxfd < startup_p[0])
maxfd = startup_p[0];
startups++;
break;
}
/*
* Got connection. Fork a child to handle it, unless
* we are in debugging mode.
*/
if (debug_flag) {
/*
* In debugging mode. Close the listening
* socket, and start processing the
* connection without forking.
*/
debug("Server will not fork when running in debugging mode.");
close_listen_socks();
sock_in = newsock;
sock_out = newsock;
startup_pipe = -1;
pid = getpid();
break;
} else {
/*
* Normal production daemon. Fork, and have
* the child process the connection. The
* parent continues listening.
*/
if ((pid = fork()) == 0) {
/*
* Child. Close the listening and max_startup
* sockets. Start using the accepted socket.
* Reinitialize logging (since our pid has
* changed). We break out of the loop to handle
* the connection.
*/
startup_pipe = startup_p[1];
close_startup_pipes();
close_listen_socks();
sock_in = newsock;
sock_out = newsock;
log_init(__progname, options.log_level, options.log_facility, log_stderr);
break;
}
}
/* Parent. Stay in the loop. */
if (pid < 0)
error("fork: %.100s", strerror(errno));
else
debug("Forked child %ld.", (long)pid);
close(startup_p[1]);
/* Mark that the key has been used (it was "given" to the child). */
if ((options.protocol & SSH_PROTO_1) &&
key_used == 0) {
/* Schedule server key regeneration alarm. */
signal(SIGALRM, key_regeneration_alarm);
alarm(options.key_regeneration_time);
key_used = 1;
}
arc4random_stir();
/* Close the new socket (the child is now taking care of it). */
close(newsock);
}
/* child process check (or debug mode) */
if (num_listen_socks < 0)
break;
}
}
/* This is the child processing a new connection. */
/*
* Create a new session and process group since the 4.4BSD
* setlogin() affects the entire process group. We don't
* want the child to be able to affect the parent.
*/
#if 0
/* XXX: this breaks Solaris */
if (!debug_flag && !inetd_flag && setsid() < 0)
error("setsid: %.100s", strerror(errno));
#endif
/*
* Disable the key regeneration alarm. We will not regenerate the
* key since we are no longer in a position to give it to anyone. We
* will not restart on SIGHUP since it no longer makes sense.
*/
alarm(0);
signal(SIGALRM, SIG_DFL);
signal(SIGHUP, SIG_DFL);
signal(SIGTERM, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGCHLD, SIG_DFL);
signal(SIGINT, SIG_DFL);
/*
* Set socket options for the connection. We want the socket to
* close as fast as possible without waiting for anything. If the
* connection is not a socket, these will do nothing.
*/
/* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */
linger.l_onoff = 1;
linger.l_linger = 5;
setsockopt(sock_in, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
/* Set keepalives if requested. */
if (options.keepalives &&
setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on,
sizeof(on)) < 0)
error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
/*
* Register our connection. This turns encryption off because we do
* not have a key.
*/
packet_set_connection(sock_in, sock_out);
remote_port = get_remote_port();
remote_ip = get_remote_ipaddr();
#ifdef LIBWRAP
/* Check whether logins are denied from this host. */
{
struct request_info req;
request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
fromhost(&req);
if (!hosts_access(&req)) {
debug("Connection refused by tcp wrapper");
refuse(&req);
/* NOTREACHED */
fatal("libwrap refuse returns");
}
}
#endif /* LIBWRAP */
/* Log the connection. */
verbose("Connection from %.500s port %d", remote_ip, remote_port);
/*
* We don\'t want to listen forever unless the other side
* successfully authenticates itself. So we set up an alarm which is
* cleared after successful authentication. A limit of zero
* indicates no limit. Note that we don\'t set the alarm in debugging
* mode; it is just annoying to have the server exit just when you
* are about to discover the bug.
*/
signal(SIGALRM, grace_alarm_handler);
if (!debug_flag)
alarm(options.login_grace_time);
sshd_exchange_identification(sock_in, sock_out);
/*
* Check that the connection comes from a privileged port.
* Rhosts-Authentication only makes sense from privileged
* programs. Of course, if the intruder has root access on his local
* machine, he can connect from any port. So do not use these
* authentication methods from machines that you do not trust.
*/
if (options.rhosts_authentication &&
(remote_port >= IPPORT_RESERVED ||
remote_port < IPPORT_RESERVED / 2)) {
debug("Rhosts Authentication disabled, "
"originating port %d not trusted.", remote_port);
options.rhosts_authentication = 0;
}
#if defined(KRB4) && !defined(KRB5)
if (!packet_connection_is_ipv4() &&
options.kerberos_authentication) {
debug("Kerberos Authentication disabled, only available for IPv4.");
options.kerberos_authentication = 0;
}
#endif /* KRB4 && !KRB5 */
#ifdef AFS
/* If machine has AFS, set process authentication group. */
if (k_hasafs()) {
k_setpag();
k_unlog();
}
#endif /* AFS */
packet_set_nonblocking();
if (use_privsep)
if ((authctxt = privsep_preauth()) != NULL)
goto authenticated;
/* perform the key exchange */
/* authenticate user and start session */
if (compat20) {
do_ssh2_kex();
authctxt = do_authentication2();
} else {
do_ssh1_kex();
authctxt = do_authentication();
}
/*
* If we use privilege separation, the unprivileged child transfers
* the current keystate and exits
*/
if (use_privsep) {
mm_send_keystate(pmonitor);
exit(0);
}
authenticated:
/*
* In privilege separation, we fork another child and prepare
* file descriptor passing.
*/
if (use_privsep) {
privsep_postauth(authctxt);
/* the monitor process [priv] will not return */
if (!compat20)
destroy_sensitive_data();
}
/* Perform session preparation. */
do_authenticated(authctxt);
/* The connection has been terminated. */
verbose("Closing connection to %.100s", remote_ip);
#ifdef USE_PAM
finish_pam();
#endif /* USE_PAM */
packet_close();
if (use_privsep)
mm_terminate();
exit(0);
}
