void svr_getopts(int argc, char ** argv) { unsigned int i; char ** next = 0; int nextisport = 0; char* recv_window_arg = NULL; char* keepalive_arg = NULL; char* idle_timeout_arg = NULL; char* keyfile = NULL; /* 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 opts.enable_compress = 1; #endif svr_opts.ipfamily = AF_UNSPEC; #ifdef DO_MOTD svr_opts.domotd = 1; #endif #ifndef DISABLE_SYSLOG svr_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 opts.weakkex = 0; for (i = 1; i < (unsigned int)argc; i++) { if (nextisport) { addportandaddress(argv[i]); nextisport = 0; continue; } if (next) { *next = argv[i]; if (*next == NULL) { dropbear_exit("Invalid null argument"); } next = 0x00; if (keyfile) { addhostkey(keyfile); keyfile = NULL; } continue; } if (argv[i][0] == '-') { switch (argv[i][1]) { 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': svr_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 #if defined AF_INET6 && AF_INET6 < AF_MAX case '4': svr_opts.ipfamily = AF_INET; break; case '6': svr_opts.ipfamily = AF_INET6; 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_FAILURE); break; case 'u': /* backwards compatibility with old urandom option */ break; #ifdef DEBUG_TRACE case 'v': debug_trace = 1; break; #endif case 'x': opts.weakkex = 1; break; default: fprintf(stderr, "Unknown argument %s\n", argv[i]); printhelp(argv[0]); exit(EXIT_FAILURE); break; } } } /* 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; } }
/* Parse pubkey options and set ses.authstate.pubkey_options accordingly. * Returns DROPBEAR_SUCCESS if key is ok for auth, DROPBEAR_FAILURE otherwise */ int svr_add_pubkey_options(buffer *options_buf, int line_num, const char* filename) { int ret = DROPBEAR_FAILURE; TRACE(("enter addpubkeyoptions")) ses.authstate.pubkey_options = (struct PubKeyOptions*)m_malloc(sizeof( struct PubKeyOptions )); buf_setpos(options_buf, 0); while (options_buf->pos < options_buf->len) { if (match_option(options_buf, "no-port-forwarding") == DROPBEAR_SUCCESS) { dropbear_log(LOG_WARNING, "Port forwarding disabled."); ses.authstate.pubkey_options->no_port_forwarding_flag = 1; goto next_option; } #ifdef ENABLE_SVR_AGENTFWD if (match_option(options_buf, "no-agent-forwarding") == DROPBEAR_SUCCESS) { dropbear_log(LOG_WARNING, "Agent forwarding disabled."); ses.authstate.pubkey_options->no_agent_forwarding_flag = 1; goto next_option; } #endif #ifdef ENABLE_X11FWD if (match_option(options_buf, "no-X11-forwarding") == DROPBEAR_SUCCESS) { dropbear_log(LOG_WARNING, "X11 forwarding disabled."); ses.authstate.pubkey_options->no_x11_forwarding_flag = 1; goto next_option; } #endif if (match_option(options_buf, "no-pty") == DROPBEAR_SUCCESS) { dropbear_log(LOG_WARNING, "Pty allocation disabled."); ses.authstate.pubkey_options->no_pty_flag = 1; goto next_option; } if (match_option(options_buf, "command=\"") == DROPBEAR_SUCCESS) { int escaped = 0; const unsigned char* command_start = buf_getptr(options_buf, 0); while (options_buf->pos < options_buf->len) { const char c = buf_getbyte(options_buf); if (!escaped && c == '"') { const int command_len = buf_getptr(options_buf, 0) - command_start; ses.authstate.pubkey_options->forced_command = m_malloc(command_len); memcpy(ses.authstate.pubkey_options->forced_command, command_start, command_len-1); ses.authstate.pubkey_options->forced_command[command_len-1] = '\0'; dropbear_log(LOG_WARNING, "Forced command '%s'", ses.authstate.pubkey_options->forced_command); goto next_option; } escaped = (!escaped && c == '\\'); } dropbear_log(LOG_WARNING, "Badly formatted command= authorized_keys option"); goto bad_option; } next_option: /* * Skip the comma, and move to the next option * (or break out if there are no more). */ if (options_buf->pos < options_buf->len && buf_getbyte(options_buf) != ',') { goto bad_option; } /* Process the next option. */ } /* parsed all options with no problem */ ret = DROPBEAR_SUCCESS; goto end; bad_option: ret = DROPBEAR_FAILURE; m_free(ses.authstate.pubkey_options); ses.authstate.pubkey_options = NULL; dropbear_log(LOG_WARNING, "Bad public key options at %s:%d", filename, line_num); end: TRACE(("leave addpubkeyoptions")) return ret; }
/* if skip_exist is set it will silently return if the key file exists */ int signkey_generate(enum signkey_type keytype, int bits, const char* filename, int skip_exist) { sign_key * key = NULL; buffer *buf = NULL; char *fn_temp = NULL; int ret = DROPBEAR_FAILURE; if (bits == 0) { bits = get_default_bits(keytype); } /* now we can generate the key */ key = new_sign_key(); seedrandom(); switch(keytype) { #ifdef DROPBEAR_RSA case DROPBEAR_SIGNKEY_RSA: key->rsakey = gen_rsa_priv_key(bits); break; #endif #ifdef DROPBEAR_DSS case DROPBEAR_SIGNKEY_DSS: key->dsskey = gen_dss_priv_key(bits); break; #endif #ifdef DROPBEAR_ECDSA case DROPBEAR_SIGNKEY_ECDSA_KEYGEN: case DROPBEAR_SIGNKEY_ECDSA_NISTP521: case DROPBEAR_SIGNKEY_ECDSA_NISTP384: case DROPBEAR_SIGNKEY_ECDSA_NISTP256: { ecc_key *ecckey = gen_ecdsa_priv_key(bits); keytype = ecdsa_signkey_type(ecckey); *signkey_key_ptr(key, keytype) = ecckey; } break; #endif default: dropbear_exit("Internal error"); } seedrandom(); buf = buf_new(MAX_PRIVKEY_SIZE); buf_put_priv_key(buf, key, keytype); sign_key_free(key); key = NULL; buf_setpos(buf, 0); fn_temp = m_malloc(strlen(filename) + 30); snprintf(fn_temp, strlen(filename)+30, "%s.tmp%d", filename, getpid()); ret = buf_writefile(buf, fn_temp); if (ret == DROPBEAR_FAILURE) { goto out; } if (link(fn_temp, filename) < 0) { /* If generating keys on connection (skipexist) it's OK to get EEXIST - we probably just lost a race with another connection to generate the key */ if (!(skip_exist && errno == EEXIST)) { dropbear_log(LOG_ERR, "Failed moving key file to %s: %s", filename, strerror(errno)); /* XXX fallback to non-atomic copy for some filesystems? */ ret = DROPBEAR_FAILURE; goto out; } } out: if (buf) { buf_burn(buf); buf_free(buf); } if (fn_temp) { unlink(fn_temp); m_free(fn_temp); } return ret; }