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- /*
- * Dropbear - a SSH2 server
- *
- * Copyright (c) 2002,2003 Matt Johnston
- * All rights reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE. */
- #include "includes.h"
- #include "runopts.h"
- #include "signkey.h"
- #include "buffer.h"
- #include "dbutil.h"
- #include "algo.h"
- #include "ecdsa.h"
- svr_runopts svr_opts; /* GLOBAL */
- static void printhelp(const char * progname);
- static void addportandaddress(const char* spec);
- static void loadhostkey(const char *keyfile, int fatal_duplicate);
- static void addhostkey(const char *keyfile);
- static void printhelp(const char * progname) {
- fprintf(stderr, "Dropbear server v%s https://matt.ucc.asn.au/dropbear/dropbear.html\n"
- "Usage: %s [options]\n"
- "-b bannerfile Display the contents of bannerfile"
- " before user login\n"
- " (default: none)\n"
- "-r keyfile Specify hostkeys (repeatable)\n"
- " defaults: \n"
- #ifdef DROPBEAR_DSS
- " dss %s\n"
- #endif
- #ifdef DROPBEAR_RSA
- " rsa %s\n"
- #endif
- #ifdef DROPBEAR_ECDSA
- " ecdsa %s\n"
- #endif
- #ifdef DROPBEAR_DELAY_HOSTKEY
- "-R Create hostkeys as required\n"
- #endif
- "-F Don't fork into background\n"
- #ifdef DISABLE_SYSLOG
- "(Syslog support not compiled in, using stderr)\n"
- #else
- "-E Log to stderr rather than syslog\n"
- #endif
- #ifdef DO_MOTD
- "-m Don't display the motd on login\n"
- #endif
- "-w Disallow root logins\n"
- #if defined(ENABLE_SVR_PASSWORD_AUTH) || defined(ENABLE_SVR_PAM_AUTH)
- "-s Disable password logins\n"
- "-g Disable password logins for root\n"
- "-B Allow blank password logins\n"
- #endif
- #ifdef ENABLE_SVR_LOCALTCPFWD
- "-j Disable local port forwarding\n"
- #endif
- #ifdef ENABLE_SVR_REMOTETCPFWD
- "-k Disable remote port forwarding\n"
- "-a Allow connections to forwarded ports from any host\n"
- #endif
- "-p [address:]port\n"
- " Listen on specified tcp port (and optionally address),\n"
- " up to %d can be specified\n"
- " (default port is %s if none specified)\n"
- "-P PidFile Create pid file PidFile\n"
- " (default %s)\n"
- #ifdef INETD_MODE
- "-i Start for inetd\n"
- #endif
- "-W <receive_window_buffer> (default %d, larger may be faster, max 1MB)\n"
- "-K <keepalive> (0 is never, default %d, in seconds)\n"
- "-I <idle_timeout> (0 is never, default %d, in seconds)\n"
- "-V Version\n"
- #ifdef DEBUG_TRACE
- "-v verbose (compiled with DEBUG_TRACE)\n"
- #endif
- ,DROPBEAR_VERSION, progname,
- #ifdef DROPBEAR_DSS
- DSS_PRIV_FILENAME,
- #endif
- #ifdef DROPBEAR_RSA
- RSA_PRIV_FILENAME,
- #endif
- #ifdef DROPBEAR_ECDSA
- ECDSA_PRIV_FILENAME,
- #endif
- DROPBEAR_MAX_PORTS, DROPBEAR_DEFPORT, DROPBEAR_PIDFILE,
- DEFAULT_RECV_WINDOW, DEFAULT_KEEPALIVE, DEFAULT_IDLE_TIMEOUT);
- }
- void svr_getopts(int argc, char ** argv) {
- unsigned int i, j;
- char ** next = 0;
- int nextisport = 0;
- char* recv_window_arg = NULL;
- char* keepalive_arg = NULL;
- char* idle_timeout_arg = NULL;
- char* keyfile = NULL;
- char c;
- /* see printhelp() for options */
- svr_opts.bannerfile = NULL;
- svr_opts.banner = NULL;
- svr_opts.forkbg = 1;
- svr_opts.norootlogin = 0;
- svr_opts.noauthpass = 0;
- svr_opts.norootpass = 0;
- svr_opts.allowblankpass = 0;
- svr_opts.inetdmode = 0;
- svr_opts.portcount = 0;
- svr_opts.hostkey = NULL;
- svr_opts.delay_hostkey = 0;
- svr_opts.pidfile = DROPBEAR_PIDFILE;
- #ifdef ENABLE_SVR_LOCALTCPFWD
- svr_opts.nolocaltcp = 0;
- #endif
- #ifdef ENABLE_SVR_REMOTETCPFWD
- svr_opts.noremotetcp = 0;
- #endif
- #ifndef DISABLE_ZLIB
- #if DROPBEAR_SERVER_DELAY_ZLIB
- opts.compress_mode = DROPBEAR_COMPRESS_DELAYED;
- #else
- opts.compress_mode = DROPBEAR_COMPRESS_ON;
- #endif
- #endif
- /* not yet
- opts.ipv4 = 1;
- opts.ipv6 = 1;
- */
- #ifdef DO_MOTD
- svr_opts.domotd = 1;
- #endif
- #ifndef DISABLE_SYSLOG
- opts.usingsyslog = 1;
- #endif
- opts.recv_window = DEFAULT_RECV_WINDOW;
- opts.keepalive_secs = DEFAULT_KEEPALIVE;
- opts.idle_timeout_secs = DEFAULT_IDLE_TIMEOUT;
-
- #ifdef ENABLE_SVR_REMOTETCPFWD
- opts.listen_fwd_all = 0;
- #endif
- for (i = 1; i < (unsigned int)argc; i++) {
- if (argv[i][0] != '-' || argv[i][1] == '\0')
- dropbear_exit("Invalid argument: %s", argv[i]);
- for (j = 1; (c = argv[i][j]) != '\0' && !next && !nextisport; j++) {
- switch (c) {
- case 'b':
- next = &svr_opts.bannerfile;
- break;
- case 'd':
- case 'r':
- next = &keyfile;
- break;
- case 'R':
- svr_opts.delay_hostkey = 1;
- break;
- case 'F':
- svr_opts.forkbg = 0;
- break;
- #ifndef DISABLE_SYSLOG
- case 'E':
- opts.usingsyslog = 0;
- break;
- #endif
- #ifdef ENABLE_SVR_LOCALTCPFWD
- case 'j':
- svr_opts.nolocaltcp = 1;
- break;
- #endif
- #ifdef ENABLE_SVR_REMOTETCPFWD
- case 'k':
- svr_opts.noremotetcp = 1;
- break;
- case 'a':
- opts.listen_fwd_all = 1;
- break;
- #endif
- #ifdef INETD_MODE
- case 'i':
- svr_opts.inetdmode = 1;
- break;
- #endif
- case 'p':
- nextisport = 1;
- break;
- case 'P':
- next = &svr_opts.pidfile;
- break;
- #ifdef DO_MOTD
- /* motd is displayed by default, -m turns it off */
- case 'm':
- svr_opts.domotd = 0;
- break;
- #endif
- case 'w':
- svr_opts.norootlogin = 1;
- break;
- case 'W':
- next = &recv_window_arg;
- break;
- case 'K':
- next = &keepalive_arg;
- break;
- case 'I':
- next = &idle_timeout_arg;
- break;
- #if defined(ENABLE_SVR_PASSWORD_AUTH) || defined(ENABLE_SVR_PAM_AUTH)
- case 's':
- svr_opts.noauthpass = 1;
- break;
- case 'g':
- svr_opts.norootpass = 1;
- break;
- case 'B':
- svr_opts.allowblankpass = 1;
- break;
- #endif
- case 'h':
- printhelp(argv[0]);
- exit(EXIT_SUCCESS);
- break;
- case 'u':
- /* backwards compatibility with old urandom option */
- break;
- #ifdef DEBUG_TRACE
- case 'v':
- debug_trace = 1;
- break;
- #endif
- case 'V':
- print_version();
- exit(EXIT_SUCCESS);
- break;
- default:
- fprintf(stderr, "Invalid option -%c\n", c);
- printhelp(argv[0]);
- exit(EXIT_FAILURE);
- break;
- }
- }
- if (!next && !nextisport)
- continue;
- if (c == '\0') {
- i++;
- j = 0;
- if (!argv[i]) {
- dropbear_exit("Missing argument");
- }
- }
- if (nextisport) {
- addportandaddress(&argv[i][j]);
- nextisport = 0;
- } else if (next) {
- *next = &argv[i][j];
- if (*next == NULL) {
- dropbear_exit("Invalid null argument");
- }
- next = 0x00;
- if (keyfile) {
- addhostkey(keyfile);
- keyfile = NULL;
- }
- }
- }
- /* Set up listening ports */
- if (svr_opts.portcount == 0) {
- svr_opts.ports[0] = m_strdup(DROPBEAR_DEFPORT);
- svr_opts.addresses[0] = m_strdup(DROPBEAR_DEFADDRESS);
- svr_opts.portcount = 1;
- }
- if (svr_opts.bannerfile) {
- struct stat buf;
- if (stat(svr_opts.bannerfile, &buf) != 0) {
- dropbear_exit("Error opening banner file '%s'",
- svr_opts.bannerfile);
- }
-
- if (buf.st_size > MAX_BANNER_SIZE) {
- dropbear_exit("Banner file too large, max is %d bytes",
- MAX_BANNER_SIZE);
- }
- svr_opts.banner = buf_new(buf.st_size);
- if (buf_readfile(svr_opts.banner, svr_opts.bannerfile)!=DROPBEAR_SUCCESS) {
- dropbear_exit("Error reading banner file '%s'",
- svr_opts.bannerfile);
- }
- buf_setpos(svr_opts.banner, 0);
- }
-
- if (recv_window_arg) {
- opts.recv_window = atol(recv_window_arg);
- if (opts.recv_window == 0 || opts.recv_window > MAX_RECV_WINDOW) {
- dropbear_exit("Bad recv window '%s'", recv_window_arg);
- }
- }
-
- if (keepalive_arg) {
- unsigned int val;
- if (m_str_to_uint(keepalive_arg, &val) == DROPBEAR_FAILURE) {
- dropbear_exit("Bad keepalive '%s'", keepalive_arg);
- }
- opts.keepalive_secs = val;
- }
- if (idle_timeout_arg) {
- unsigned int val;
- if (m_str_to_uint(idle_timeout_arg, &val) == DROPBEAR_FAILURE) {
- dropbear_exit("Bad idle_timeout '%s'", idle_timeout_arg);
- }
- opts.idle_timeout_secs = val;
- }
- }
- static void addportandaddress(const char* spec) {
- char *spec_copy = NULL, *myspec = NULL, *port = NULL, *address = NULL;
- if (svr_opts.portcount < DROPBEAR_MAX_PORTS) {
- /* We don't free it, it becomes part of the runopt state */
- spec_copy = m_strdup(spec);
- myspec = spec_copy;
- if (myspec[0] == '[') {
- myspec++;
- port = strchr(myspec, ']');
- if (!port) {
- /* Unmatched [ -> exit */
- dropbear_exit("Bad listen address");
- }
- port[0] = '\0';
- port++;
- if (port[0] != ':') {
- /* Missing port -> exit */
- dropbear_exit("Missing port");
- }
- } else {
- /* search for ':', that separates address and port */
- port = strrchr(myspec, ':');
- }
- if (!port) {
- /* no ':' -> the whole string specifies just a port */
- port = myspec;
- } else {
- /* Split the address/port */
- port[0] = '\0';
- port++;
- address = myspec;
- }
- if (!address) {
- /* no address given -> fill in the default address */
- address = DROPBEAR_DEFADDRESS;
- }
- if (port[0] == '\0') {
- /* empty port -> exit */
- dropbear_exit("Bad port");
- }
- svr_opts.ports[svr_opts.portcount] = m_strdup(port);
- svr_opts.addresses[svr_opts.portcount] = m_strdup(address);
- svr_opts.portcount++;
- m_free(spec_copy);
- }
- }
- static void disablekey(int type) {
- int i;
- TRACE(("Disabling key type %d", type))
- for (i = 0; sshhostkey[i].name != NULL; i++) {
- if (sshhostkey[i].val == type) {
- sshhostkey[i].usable = 0;
- break;
- }
- }
- }
- static void loadhostkey_helper(const char *name, void** src, void** dst, int fatal_duplicate) {
- if (*dst) {
- if (fatal_duplicate) {
- dropbear_exit("Only one %s key can be specified", name);
- }
- } else {
- *dst = *src;
- *src = NULL;
- }
- }
- /* Must be called after syslog/etc is working */
- static void loadhostkey(const char *keyfile, int fatal_duplicate) {
- sign_key * read_key = new_sign_key();
- enum signkey_type type = DROPBEAR_SIGNKEY_ANY;
- if (readhostkey(keyfile, read_key, &type) == DROPBEAR_FAILURE) {
- if (!svr_opts.delay_hostkey) {
- dropbear_log(LOG_WARNING, "Failed loading %s", keyfile);
- }
- }
- #ifdef DROPBEAR_RSA
- if (type == DROPBEAR_SIGNKEY_RSA) {
- loadhostkey_helper("RSA", (void**)&read_key->rsakey, (void**)&svr_opts.hostkey->rsakey, fatal_duplicate);
- }
- #endif
- #ifdef DROPBEAR_DSS
- if (type == DROPBEAR_SIGNKEY_DSS) {
- loadhostkey_helper("DSS", (void**)&read_key->dsskey, (void**)&svr_opts.hostkey->dsskey, fatal_duplicate);
- }
- #endif
- #ifdef DROPBEAR_ECDSA
- #ifdef DROPBEAR_ECC_256
- if (type == DROPBEAR_SIGNKEY_ECDSA_NISTP256) {
- loadhostkey_helper("ECDSA256", (void**)&read_key->ecckey256, (void**)&svr_opts.hostkey->ecckey256, fatal_duplicate);
- }
- #endif
- #ifdef DROPBEAR_ECC_384
- if (type == DROPBEAR_SIGNKEY_ECDSA_NISTP384) {
- loadhostkey_helper("ECDSA384", (void**)&read_key->ecckey384, (void**)&svr_opts.hostkey->ecckey384, fatal_duplicate);
- }
- #endif
- #ifdef DROPBEAR_ECC_521
- if (type == DROPBEAR_SIGNKEY_ECDSA_NISTP521) {
- loadhostkey_helper("ECDSA521", (void**)&read_key->ecckey521, (void**)&svr_opts.hostkey->ecckey521, fatal_duplicate);
- }
- #endif
- #endif /* DROPBEAR_ECDSA */
- sign_key_free(read_key);
- TRACE(("leave loadhostkey"))
- }
- static void addhostkey(const char *keyfile) {
- if (svr_opts.num_hostkey_files >= MAX_HOSTKEYS) {
- dropbear_exit("Too many hostkeys");
- }
- svr_opts.hostkey_files[svr_opts.num_hostkey_files] = m_strdup(keyfile);
- svr_opts.num_hostkey_files++;
- }
- void load_all_hostkeys() {
- int i;
- int disable_unset_keys = 1;
- int any_keys = 0;
- svr_opts.hostkey = new_sign_key();
- for (i = 0; i < svr_opts.num_hostkey_files; i++) {
- char *hostkey_file = svr_opts.hostkey_files[i];
- loadhostkey(hostkey_file, 1);
- m_free(hostkey_file);
- }
- #ifdef DROPBEAR_RSA
- loadhostkey(RSA_PRIV_FILENAME, 0);
- #endif
- #ifdef DROPBEAR_DSS
- loadhostkey(DSS_PRIV_FILENAME, 0);
- #endif
- #ifdef DROPBEAR_ECDSA
- loadhostkey(ECDSA_PRIV_FILENAME, 0);
- #endif
- #ifdef DROPBEAR_DELAY_HOSTKEY
- if (svr_opts.delay_hostkey) {
- disable_unset_keys = 0;
- }
- #endif
- #ifdef DROPBEAR_RSA
- if (disable_unset_keys && !svr_opts.hostkey->rsakey) {
- disablekey(DROPBEAR_SIGNKEY_RSA);
- } else {
- any_keys = 1;
- }
- #endif
- #ifdef DROPBEAR_DSS
- if (disable_unset_keys && !svr_opts.hostkey->dsskey) {
- disablekey(DROPBEAR_SIGNKEY_DSS);
- } else {
- any_keys = 1;
- }
- #endif
- #ifdef DROPBEAR_ECDSA
- #ifdef DROPBEAR_ECC_256
- if ((disable_unset_keys || ECDSA_DEFAULT_SIZE != 256)
- && !svr_opts.hostkey->ecckey256) {
- disablekey(DROPBEAR_SIGNKEY_ECDSA_NISTP256);
- } else {
- any_keys = 1;
- }
- #endif
- #ifdef DROPBEAR_ECC_384
- if ((disable_unset_keys || ECDSA_DEFAULT_SIZE != 384)
- && !svr_opts.hostkey->ecckey384) {
- disablekey(DROPBEAR_SIGNKEY_ECDSA_NISTP384);
- } else {
- any_keys = 1;
- }
- #endif
- #ifdef DROPBEAR_ECC_521
- if ((disable_unset_keys || ECDSA_DEFAULT_SIZE != 521)
- && !svr_opts.hostkey->ecckey521) {
- disablekey(DROPBEAR_SIGNKEY_ECDSA_NISTP521);
- } else {
- any_keys = 1;
- }
- #endif
- #endif /* DROPBEAR_ECDSA */
- if (!any_keys) {
- dropbear_exit("No hostkeys available. 'dropbear -R' may be useful or run dropbearkey.");
- }
- }
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