2 invitation.c -- Create and accept invitations
3 Copyright (C) 2013 Guus Sliepen <guus@tinc-vpn.org>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 #include "control_common.h"
26 #include "invitation.h"
36 int addressfamily = AF_UNSPEC;
38 static void scan_for_hostname(const char *filename, char **hostname, char **port) {
39 if(!filename || (*hostname && *port))
42 FILE *f = fopen(filename, "r");
46 while(fgets(line, sizeof line, f)) {
50 p += strcspn(p, "\t =");
53 q = p + strspn(p, "\t ");
55 q += 1 + strspn(q + 1, "\t ");
57 p = q + strcspn(q, "\t ");
60 p += strspn(p, "\t ");
61 p[strcspn(p, "\t ")] = 0;
63 if(!*port && !strcasecmp(line, "Port")) {
65 } else if(!*hostname && !strcasecmp(line, "Address")) {
66 *hostname = xstrdup(q);
73 if(*hostname && *port)
80 char *get_my_hostname() {
81 char *hostname = NULL;
83 char *hostport = NULL;
84 char *name = get_my_name(false);
85 char *filename = NULL;
87 // Use first Address statement in own host config file
89 xasprintf(&filename, "%s" SLASH "hosts" SLASH "%s", confbase, name);
90 scan_for_hostname(filename, &hostname, &port);
91 scan_for_hostname(tinc_conf, &hostname, &port);
97 // If that doesn't work, guess externally visible hostname
98 fprintf(stderr, "Trying to discover externally visible hostname...\n");
99 struct addrinfo *ai = str2addrinfo("tinc-vpn.org", "80", SOCK_STREAM);
100 struct addrinfo *aip = ai;
101 static const char request[] = "GET http://tinc-vpn.org/host.cgi HTTP/1.0\r\n\r\n";
104 int s = socket(aip->ai_family, aip->ai_socktype, aip->ai_protocol);
106 if(connect(s, aip->ai_addr, aip->ai_addrlen)) {
112 send(s, request, sizeof request - 1, 0);
113 int len = recv(s, line, sizeof line - 1, MSG_WAITALL);
116 if(line[len - 1] == '\n')
118 char *p = strrchr(line, '\n');
120 hostname = xstrdup(p + 1);
133 // Check that the hostname is reasonable
135 for(char *p = hostname; *p; p++) {
136 if(isalnum(*p) || *p == '-' || *p == '.' || *p == ':')
138 // If not, forget it.
146 printf("Please enter your host's external address or hostname");
148 printf(" [%s]", hostname);
152 if(!fgets(line, sizeof line, stdin)) {
153 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
165 for(char *p = line; *p; p++) {
166 if(isalnum(*p) || *p == '-' || *p == '.')
168 fprintf(stderr, "Invalid address or hostname.\n");
173 hostname = xstrdup(line);
177 FILE *f = fopen(filename, "a");
179 fprintf(f, "\nAddress = %s\n", hostname);
182 fprintf(stderr, "Could not append Address to %s: %s\n", filename, strerror(errno));
188 if(strchr(hostname, ':'))
189 xasprintf(&hostport, "[%s]:%s", hostname, port);
191 xasprintf(&hostport, "%s:%s", hostname, port);
203 static bool fcopy(FILE *out, const char *filename) {
204 FILE *in = fopen(filename, "r");
206 fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
212 while((len = fread(buf, 1, sizeof buf, in)))
213 fwrite(buf, len, 1, out);
218 int cmd_invite(int argc, char *argv[]) {
220 fprintf(stderr, "Not enough arguments!\n");
224 // Check validity of the new node's name
225 if(!check_id(argv[1])) {
226 fprintf(stderr, "Invalid name for node.\n");
230 char *myname = get_my_name(true);
234 // Ensure no host configuration file with that name exists
235 char *filename = NULL;
236 xasprintf(&filename, "%s" SLASH "hosts" SLASH "%s", confbase, argv[1]);
237 if(!access(filename, F_OK)) {
239 fprintf(stderr, "A host config file for %s already exists!\n", argv[1]);
244 // If a daemon is running, ensure no other nodes now about this name
246 if(connect_tincd(false)) {
247 sendline(fd, "%d %d", CONTROL, REQ_DUMP_NODES);
249 while(recvline(fd, line, sizeof line)) {
252 if(sscanf(line, "%d %d %s", &code, &req, node) != 3)
254 if(!strcmp(node, argv[1]))
259 fprintf(stderr, "A node with name %s is already known!\n", argv[1]);
266 xasprintf(&filename, "%s" SLASH "invitations", confbase);
267 if(mkdir(filename, 0700) && errno != EEXIST) {
268 fprintf(stderr, "Could not create directory %s: %s\n", filename, strerror(errno));
273 // Count the number of valid invitations, clean up old ones
274 DIR *dir = opendir(filename);
276 fprintf(stderr, "Could not read directory %s: %s\n", filename, strerror(errno));
284 time_t deadline = time(NULL) - 604800; // 1 week in the past
286 while((ent = readdir(dir))) {
287 if(strlen(ent->d_name) != 24)
291 xasprintf(&invname, "%s" SLASH "%s", filename, ent->d_name);
292 if(!stat(invname, &st)) {
293 if(deadline < st.st_mtime)
298 fprintf(stderr, "Could not stat %s: %s\n", invname, strerror(errno));
305 fprintf(stderr, "Error while reading directory %s: %s\n", filename, strerror(errno));
315 xasprintf(&filename, "%s" SLASH "invitations" SLASH "ecdsa_key.priv", confbase);
317 // Remove the key if there are no outstanding invitations.
321 // Create a new key if necessary.
322 FILE *f = fopen(filename, "r");
324 if(errno != ENOENT) {
325 fprintf(stderr, "Could not read %s: %s\n", filename, strerror(errno));
330 key = ecdsa_generate();
335 f = fopen(filename, "w");
337 fprintf(stderr, "Could not write %s: %s\n", filename, strerror(errno));
341 chmod(filename, 0600);
342 ecdsa_write_pem_private_key(key, f);
345 if(connect_tincd(false))
346 sendline(fd, "%d %d", CONTROL, REQ_RELOAD);
348 key = ecdsa_read_pem_private_key(f);
351 fprintf(stderr, "Could not read private key from %s\n", filename);
358 // Create a hash of the key.
359 char *fingerprint = ecdsa_get_base64_public_key(key);
360 digest_t *digest = digest_open_by_name("sha256", 18);
363 digest_create(digest, fingerprint, strlen(fingerprint), hash);
364 b64encode_urlsafe(hash, hash, 18);
366 // Create a random cookie for this invitation.
368 randomize(cookie, 18);
370 // Create a filename that doesn't reveal the cookie itself
371 char buf[18 + strlen(fingerprint)];
373 memcpy(buf, cookie, 18);
374 memcpy(buf + 18, fingerprint, sizeof buf - 18);
375 digest_create(digest, buf, sizeof buf, cookiehash);
376 b64encode_urlsafe(cookiehash, cookiehash, 18);
378 b64encode_urlsafe(cookie, cookie, 18);
380 // Create a file containing the details of the invitation.
381 xasprintf(&filename, "%s" SLASH "invitations" SLASH "%s", confbase, cookiehash);
382 int ifd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
384 fprintf(stderr, "Could not create invitation file %s: %s\n", filename, strerror(errno));
388 f = fdopen(ifd, "w");
392 // Get the local address
393 char *address = get_my_hostname();
395 // Fill in the details.
396 fprintf(f, "Name = %s\n", argv[1]);
398 fprintf(f, "NetName = %s\n", netname);
399 fprintf(f, "ConnectTo = %s\n", myname);
401 // Copy Broadcast and Mode
402 FILE *tc = fopen(tinc_conf, "r");
405 while(fgets(buf, sizeof buf, tc)) {
406 if((!strncasecmp(buf, "Mode", 4) && strchr(" \t=", buf[4]))
407 || (!strncasecmp(buf, "Broadcast", 9) && strchr(" \t=", buf[9])))
413 fprintf(f, "#---------------------------------------------------------------#\n");
414 fprintf(f, "Name = %s\n", myname);
417 xasprintf(&filename2, "%s" SLASH "hosts" SLASH "%s", confbase, myname);
422 // Create an URL from the local address, key hash and cookie
424 xasprintf(&url, "%s/%s%s", address, hash, cookie);
426 // Call the inviation-created script
428 xasprintf(&envp[0], "NAME=%s", myname);
429 xasprintf(&envp[1], "NETNAME=%s", netname);
430 xasprintf(&envp[2], "NODE=%s", argv[1]);
431 xasprintf(&envp[3], "INVITATION_FILE=%s", filename);
432 xasprintf(&envp[4], "INVITATION_URL=%s", url);
433 execute_script("invitation-created", envp);
434 for(int i = 0; i < 6 && envp[i]; i++)
446 static char cookie[18];
447 static sptps_t sptps;
449 static size_t datalen;
450 static bool success = false;
452 static char cookie[18], hash[18];
454 static char *get_line(const char **data) {
463 static char line[1024];
464 const char *end = strchr(*data, '\n');
465 size_t len = end ? end - *data : strlen(*data);
466 if(len >= sizeof line) {
467 fprintf(stderr, "Maximum line length exceeded!\n");
470 if(len && !isprint(**data))
473 memcpy(line, *data, len);
484 static char *get_value(const char *data, const char *var) {
485 char *line = get_line(&data);
489 char *sep = line + strcspn(line, " \t=");
490 char *val = sep + strspn(sep, " \t");
492 val += 1 + strspn(val + 1, " \t");
494 if(strcasecmp(line, var))
499 static char *grep(const char *data, const char *var) {
500 static char value[1024];
502 const char *p = data;
503 int varlen = strlen(var);
505 // Skip all lines not starting with var
506 while(strncasecmp(p, var, varlen) || !strchr(" \t=", p[varlen])) {
518 p += strspn(p, " \t");
520 p += 1 + strspn(p + 1, " \t");
522 const char *e = strchr(p, '\n');
526 if(e - p >= sizeof value) {
527 fprintf(stderr, "Maximum line length exceeded!\n");
531 memcpy(value, p, e - p);
536 static bool finalize_join(void) {
537 char *name = xstrdup(get_value(data, "Name"));
539 fprintf(stderr, "No Name found in invitation!\n");
543 if(!check_id(name)) {
544 fprintf(stderr, "Invalid Name found in invitation: %s!\n", name);
549 netname = grep(data, "NetName");
551 bool ask_netname = false;
552 char temp_netname[32];
565 xasprintf(&tinc_conf, "%s" SLASH "tinc.conf", confbase);
566 xasprintf(&hosts_dir, "%s" SLASH "hosts", confbase);
568 if(!access(tinc_conf, F_OK)) {
569 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
570 if(!tty || confbasegiven)
573 // Generate a random netname, ask for a better one later.
575 snprintf(temp_netname, sizeof temp_netname, "join_%x", rand());
576 netname = temp_netname;
580 if(mkdir(confbase, 0777) && errno != EEXIST) {
581 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
585 if(mkdir(hosts_dir, 0777) && errno != EEXIST) {
586 fprintf(stderr, "Could not create directory %s: %s\n", hosts_dir, strerror(errno));
590 FILE *f = fopen(tinc_conf, "w");
592 fprintf(stderr, "Could not create file %s: %s\n", tinc_conf, strerror(errno));
596 fprintf(f, "Name = %s\n", name);
599 xasprintf(&filename, "%s" SLASH "%s", hosts_dir, name);
600 FILE *fh = fopen(filename, "w");
602 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
606 // Filter first chunk on approved keywords, split between tinc.conf and hosts/Name
607 // Other chunks go unfiltered to their respective host config files
608 const char *p = data;
611 while((l = get_line(&p))) {
616 // Split line into variable and value
617 int len = strcspn(l, "\t =");
619 value += strspn(value, "\t ");
622 value += strspn(value, "\t ");
627 if(!strcasecmp(l, "Name"))
628 if(strcmp(value, name))
632 else if(!strcasecmp(l, "NetName"))
635 // Check the list of known variables
638 for(i = 0; variables[i].name; i++) {
639 if(strcasecmp(l, variables[i].name))
645 // Ignore unknown and unsafe variables
647 fprintf(stderr, "Ignoring unknown variable '%s' in invitation.\n", l);
649 } else if(!(variables[i].type & VAR_SAFE)) {
650 fprintf(stderr, "Ignoring unsafe variable '%s' in invitation.\n", l);
654 // Copy the safe variable to the right config file
655 fprintf(variables[i].type & VAR_HOST ? fh : f, "%s = %s\n", l, value);
661 while(l && !strcasecmp(l, "Name")) {
662 if(!check_id(value)) {
663 fprintf(stderr, "Invalid Name found in invitation.\n");
667 if(!strcmp(value, name)) {
668 fprintf(stderr, "Secondary chunk would overwrite our own host config file.\n");
672 xasprintf(&filename, "%s" SLASH "%s", hosts_dir, value);
673 f = fopen(filename, "w");
676 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
680 while((l = get_line(&p))) {
681 if(!strcmp(l, "#---------------------------------------------------------------#"))
683 int len = strcspn(l, "\t =");
684 if(len == 4 && !strncasecmp(l, "Name", 4)) {
686 value += strspn(value, "\t ");
689 value += strspn(value, "\t ");
703 // Generate our key and send a copy to the server
704 ecdsa_t *key = ecdsa_generate();
708 char *b64key = ecdsa_get_base64_public_key(key);
712 xasprintf(&filename, "%s" SLASH "ecdsa_key.priv", confbase);
713 f = fopenmask(filename, "w", 0600);
715 if(!ecdsa_write_pem_private_key(key, f)) {
716 fprintf(stderr, "Error writing private key!\n");
724 fprintf(fh, "ECDSAPublicKey = %s\n", b64key);
726 sptps_send_record(&sptps, 1, b64key, strlen(b64key));
730 rsa_t *rsa = rsa_generate(2048, 0x1001);
731 xasprintf(&filename, "%s" SLASH "rsa_key.priv", confbase);
732 f = fopenmask(filename, "w", 0600);
734 rsa_write_pem_private_key(rsa, f);
737 rsa_write_pem_public_key(rsa, fh);
747 fprintf(stderr, "Enter a new netname: ");
748 if(!fgets(line, sizeof line, stdin)) {
749 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
752 if(!*line || *line == '\n')
755 line[strlen(line) - 1] = 0;
758 xasprintf(&newbase, CONFDIR SLASH "tinc" SLASH "%s", line);
759 if(rename(confbase, newbase)) {
760 fprintf(stderr, "Error trying to rename %s to %s: %s\n", confbase, newbase, strerror(errno));
774 static bool invitation_send(void *handle, uint8_t type, const char *data, size_t len) {
776 int result = send(sock, data, len, 0);
777 if(result == -1 && errno == EINTR)
787 static bool invitation_receive(void *handle, uint8_t type, const char *msg, uint16_t len) {
789 case SPTPS_HANDSHAKE:
790 return sptps_send_record(&sptps, 0, cookie, sizeof cookie);
793 data = xrealloc(data, datalen + len + 1);
794 memcpy(data + datalen, msg, len);
800 return finalize_join();
803 fprintf(stderr, "Invitation succesfully accepted.\n");
804 shutdown(sock, SHUT_RDWR);
815 int cmd_join(int argc, char *argv[]) {
821 fprintf(stderr, "Too many arguments!\n");
825 // Make sure confbase exists and is accessible.
826 if(strcmp(confdir, confbase) && mkdir(confdir, 0755) && errno != EEXIST) {
827 fprintf(stderr, "Could not create directory %s: %s\n", confdir, strerror(errno));
831 if(mkdir(confbase, 0777) && errno != EEXIST) {
832 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
836 if(access(confbase, R_OK | W_OK | X_OK)) {
837 fprintf(stderr, "No permission to write in directory %s: %s\n", confbase, strerror(errno));
841 // If a netname or explicit configuration directory is specified, check for an existing tinc.conf.
842 if((netname || confbasegiven) && !access(tinc_conf, F_OK)) {
843 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
847 // Either read the invitation from the command line or from stdin.
851 invitation = argv[1];
854 printf("Enter invitation URL: ");
858 if(!fgets(line, sizeof line, stdin)) {
859 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
865 // Parse the invitation URL.
868 char *slash = strchr(invitation, '/');
874 if(strlen(slash) != 48)
877 char *address = invitation;
879 if(*address == '[') {
881 char *bracket = strchr(address, ']');
885 if(bracket[1] == ':')
888 port = strchr(address, ':');
896 if(!b64decode(slash, hash, 18) || !b64decode(slash + 24, cookie, 18))
899 // Generate a throw-away key for the invitation.
900 ecdsa_t *key = ecdsa_generate();
904 char *b64key = ecdsa_get_base64_public_key(key);
906 // Connect to the tinc daemon mentioned in the URL.
907 struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
911 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
913 fprintf(stderr, "Could not open socket: %s\n", strerror(errno));
917 if(connect(sock, ai->ai_addr, ai->ai_addrlen)) {
918 fprintf(stderr, "Could not connect to %s port %s: %s\n", address, port, strerror(errno));
923 fprintf(stderr, "Connected to %s port %s...\n", address, port);
925 // Tell him we have an invitation, and give him our throw-away key.
926 int len = snprintf(line, sizeof line, "0 ?%s %d.%d\n", b64key, PROT_MAJOR, PROT_MINOR);
927 if(len <= 0 || len >= sizeof line)
930 if(!sendline(sock, "0 ?%s %d.%d", b64key, PROT_MAJOR, 1)) {
931 fprintf(stderr, "Error sending request to %s port %s: %s\n", address, port, strerror(errno));
936 char hisname[4096] = "";
937 int code, hismajor, hisminor = 0;
939 if(!recvline(sock, line, sizeof line) || sscanf(line, "%d %s %d.%d", &code, hisname, &hismajor, &hisminor) < 3 || code != 0 || hismajor != PROT_MAJOR || !check_id(hisname) || !recvline(sock, line, sizeof line) || !rstrip(line) || sscanf(line, "%d ", &code) != 1 || code != ACK || strlen(line) < 3) {
940 fprintf(stderr, "Cannot read greeting from peer\n");
945 // Check if the hash of the key he gave us matches the hash in the URL.
946 char *fingerprint = line + 2;
947 digest_t *digest = digest_open_by_name("sha256", 18);
951 if(!digest_create(digest, fingerprint, strlen(fingerprint), hishash)) {
952 fprintf(stderr, "Could not create digest\n%s\n", line + 2);
955 if(memcmp(hishash, hash, 18)) {
956 fprintf(stderr, "Peer has an invalid key!\n%s\n", line + 2);
961 ecdsa_t *hiskey = ecdsa_set_base64_public_key(fingerprint);
965 // Start an SPTPS session
966 if(!sptps_start(&sptps, NULL, true, false, key, hiskey, "tinc invitation", 15, invitation_send, invitation_receive))
969 // Feed rest of input buffer to SPTPS
970 if(!sptps_receive_data(&sptps, buffer, blen))
973 while((len = recv(sock, line, sizeof line, 0))) {
977 fprintf(stderr, "Error reading data from %s port %s: %s\n", address, port, strerror(errno));
981 if(!sptps_receive_data(&sptps, line, len))
991 fprintf(stderr, "Connection closed by peer, invitation cancelled.\n");
998 fprintf(stderr, "Invalid invitation URL.\n");