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"
35 int addressfamily = AF_UNSPEC;
37 char *get_my_hostname() {
38 char *hostname = NULL;
40 char *hostport = NULL;
41 char *name = get_my_name(false);
42 char *filename = NULL;
44 // Use first Address statement in own host config file
46 xasprintf(&filename, "%s" SLASH "hosts" SLASH "%s", confbase, name);
47 FILE *f = fopen(filename, "r");
49 while(fgets(line, sizeof line, f)) {
53 p += strcspn(p, "\t =");
56 q = p + strspn(p, "\t ");
58 q += 1 + strspn(q + 1, "\t ");
60 p = q + strcspn(q, "\t ");
63 p += strspn(p, "\t ");
64 p[strcspn(p, "\t ")] = 0;
65 if(!port && !strcasecmp(line, "Port")) {
69 if(strcasecmp(line, "Address"))
71 hostname = xstrdup(q);
85 // If that doesn't work, guess externally visible hostname
86 fprintf(stderr, "Trying to discover externally visible hostname...\n");
87 struct addrinfo *ai = str2addrinfo("ifconfig.me", "80", SOCK_STREAM);
88 static const char request[] = "GET /host HTTP/1.0\r\n\r\n";
90 int s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
92 if(connect(s, ai->ai_addr, ai->ai_addrlen)) {
98 send(s, request, sizeof request - 1, 0);
99 int len = recv(s, line, sizeof line - 1, MSG_WAITALL);
102 if(line[len - 1] == '\n')
104 char *p = strrchr(line, '\n');
106 hostname = xstrdup(p + 1);
113 // Check that the hostname is reasonable
115 for(char *p = hostname; *p; p++) {
116 if(isalnum(*p) || *p == '-' || *p == '.')
118 // If not, forget it.
126 printf("Please enter your host's external address or hostname");
128 printf(" [%s]", hostname);
132 if(!fgets(line, sizeof line, stdin)) {
133 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
145 for(char *p = line; *p; p++) {
146 if(isalnum(*p) || *p == '-' || *p == '.')
148 fprintf(stderr, "Invalid address or hostname.\n");
153 hostname = xstrdup(line);
157 FILE *f = fopen(filename, "a");
159 fprintf(f, "\nAddress = %s\n", hostname);
162 fprintf(stderr, "Could not append Address to %s: %s\n", filename, strerror(errno));
168 if(strchr(hostname, ':'))
169 xasprintf(&hostport, "[%s]:%s", hostname, port);
171 xasprintf(&hostport, "%s:%s", hostname, port);
183 static bool fcopy(FILE *out, const char *filename) {
184 FILE *in = fopen(filename, "r");
186 fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
192 while((len = fread(buf, 1, sizeof buf, in)))
193 fwrite(buf, len, 1, out);
198 int cmd_invite(int argc, char *argv[]) {
200 fprintf(stderr, "Not enough arguments!\n");
204 // Check validity of the new node's name
205 if(!check_id(argv[1])) {
206 fprintf(stderr, "Invalid name for node.\n");
210 char *myname = get_my_name(true);
214 // Ensure no host configuration file with that name exists
215 char *filename = NULL;
216 xasprintf(&filename, "%s" SLASH "hosts" SLASH "%s", confbase, argv[1]);
217 if(!access(filename, F_OK)) {
219 fprintf(stderr, "A host config file for %s already exists!\n", argv[1]);
224 // If a daemon is running, ensure no other nodes now about this name
226 if(connect_tincd(false)) {
227 sendline(fd, "%d %d", CONTROL, REQ_DUMP_NODES);
229 while(recvline(fd, line, sizeof line)) {
232 if(sscanf(line, "%d %d %s", &code, &req, node) != 3)
234 if(!strcmp(node, argv[1]))
239 fprintf(stderr, "A node with name %s is already known!\n", argv[1]);
246 xasprintf(&filename, "%s" SLASH "invitations", confbase);
247 if(mkdir(filename, 0700) && errno != EEXIST) {
248 fprintf(stderr, "Could not create directory %s: %s\n", filename, strerror(errno));
253 // Count the number of valid invitations, clean up old ones
254 DIR *dir = opendir(filename);
256 fprintf(stderr, "Could not read directory %s: %s\n", filename, strerror(errno));
264 time_t deadline = time(NULL) - 604800; // 1 week in the past
266 while((ent = readdir(dir))) {
267 if(strlen(ent->d_name) != 24)
271 xasprintf(&invname, "%s" SLASH "%s", filename, ent->d_name);
272 if(!stat(invname, &st)) {
273 if(deadline < st.st_mtime)
278 fprintf(stderr, "Could not stat %s: %s\n", invname, strerror(errno));
285 fprintf(stderr, "Error while reading directory %s: %s\n", filename, strerror(errno));
295 xasprintf(&filename, "%s" SLASH "invitations" SLASH "ecdsa_key.priv", confbase);
297 // Remove the key if there are no outstanding invitations.
301 // Create a new key if necessary.
302 FILE *f = fopen(filename, "r");
304 if(errno != ENOENT) {
305 fprintf(stderr, "Could not read %s: %s\n", filename, strerror(errno));
310 key = ecdsa_generate();
315 f = fopen(filename, "w");
317 fprintf(stderr, "Could not write %s: %s\n", filename, strerror(errno));
321 chmod(filename, 0600);
322 ecdsa_write_pem_private_key(key, f);
324 key = ecdsa_read_pem_private_key(f);
326 fprintf(stderr, "Could not read private key from %s\n", filename);
333 // Create a hash of the key.
334 char *fingerprint = ecdsa_get_base64_public_key(key);
335 digest_t *digest = digest_open_by_name("sha256", 18);
338 digest_create(digest, fingerprint, strlen(fingerprint), hash);
339 b64encode_urlsafe(hash, hash, 18);
341 // Create a random cookie for this invitation.
343 randomize(cookie, 18);
344 b64encode_urlsafe(cookie, cookie, 18);
346 // Create a file containing the details of the invitation.
347 xasprintf(&filename, "%s" SLASH "invitations" SLASH "%s", confbase, cookie);
348 int ifd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
350 fprintf(stderr, "Could not create invitation file %s: %s\n", filename, strerror(errno));
355 f = fdopen(ifd, "w");
359 // Fill in the details.
360 fprintf(f, "Name = %s\n", argv[1]);
362 fprintf(f, "NetName = %s\n", netname);
363 fprintf(f, "ConnectTo = %s\n", myname);
364 // TODO: copy Broadcast and Mode
365 fprintf(f, "#---------------------------------------------------------------#\n");
366 fprintf(f, "Name = %s\n", myname);
368 xasprintf(&filename, "%s" SLASH "hosts" SLASH "%s", confbase, myname);
372 // Create an URL from the local address, key hash and cookie
373 char *address = get_my_hostname();
374 printf("%s/%s%s\n", address, hash, cookie);
382 static char cookie[18];
383 static sptps_t sptps;
385 static size_t datalen;
386 static bool success = false;
388 static char cookie[18], hash[18];
390 static char *get_line(const char **data) {
399 static char line[1024];
400 const char *end = strchr(*data, '\n');
401 size_t len = end ? end - *data : strlen(*data);
402 if(len >= sizeof line) {
403 fprintf(stderr, "Maximum line length exceeded!\n");
406 if(len && !isprint(**data))
409 memcpy(line, *data, len);
420 static char *get_value(const char *data, const char *var) {
421 char *line = get_line(&data);
425 char *sep = line + strcspn(line, " \t=");
426 char *val = sep + strspn(sep, " \t");
428 val += 1 + strspn(val + 1, " \t");
430 if(strcasecmp(line, var))
435 static char *grep(const char *data, const char *var) {
436 static char value[1024];
438 const char *p = data;
439 int varlen = strlen(var);
441 // Skip all lines not starting with var
442 while(strncasecmp(p, var, varlen) || !strchr(" \t=", p[varlen])) {
454 p += strspn(p, " \t");
456 p += 1 + strspn(p + 1, " \t");
458 const char *e = strchr(p, '\n');
462 if(e - p >= sizeof value) {
463 fprintf(stderr, "Maximum line length exceeded!\n");
467 memcpy(value, p, e - p);
472 static bool finalize_join(void) {
473 char *name = xstrdup(get_value(data, "Name"));
475 fprintf(stderr, "No Name found in invitation!\n");
479 if(!check_id(name)) {
480 fprintf(stderr, "Invalid Name found in invitation: %s!\n", name);
485 netname = grep(data, "NetName");
487 bool ask_netname = false;
488 char temp_netname[32];
501 xasprintf(&tinc_conf, "%s" SLASH "tinc.conf", confbase);
502 xasprintf(&hosts_dir, "%s" SLASH "hosts", confbase);
504 if(!access(tinc_conf, F_OK)) {
505 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
506 if(!tty || confbasegiven)
509 // Generate a random netname, ask for a better one later.
511 snprintf(temp_netname, sizeof temp_netname, "join_%x", rand());
512 netname = temp_netname;
516 if(mkdir(confbase, 0777) && errno != EEXIST) {
517 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
521 if(mkdir(hosts_dir, 0777) && errno != EEXIST) {
522 fprintf(stderr, "Could not create directory %s: %s\n", hosts_dir, strerror(errno));
526 FILE *f = fopen(tinc_conf, "w");
528 fprintf(stderr, "Could not create file %s: %s\n", tinc_conf, strerror(errno));
532 fprintf(f, "Name = %s\n", name);
535 xasprintf(&filename, "%s" SLASH "%s", hosts_dir, name);
536 FILE *fh = fopen(filename, "w");
538 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
542 // Filter first chunk on approved keywords, split between tinc.conf and hosts/Name
543 // Other chunks go unfiltered to their respective host config files
544 const char *p = data;
547 while((l = get_line(&p))) {
552 // Split line into variable and value
553 int len = strcspn(l, "\t =");
555 value += strspn(value, "\t ");
558 value += strspn(value, "\t ");
563 if(!strcasecmp(l, "Name"))
564 if(strcmp(value, name))
568 else if(!strcasecmp(l, "NetName"))
571 // Check the list of known variables
574 for(i = 0; variables[i].name; i++) {
575 if(strcasecmp(l, variables[i].name))
581 // Ignore unknown and unsafe variables
583 fprintf(stderr, "Ignoring unknown variable '%s' in invitation.\n", l);
585 } else if(!(variables[i].type & VAR_SAFE)) {
586 fprintf(stderr, "Ignoring unsafe variable '%s' in invitation.\n", l);
590 // Copy the safe variable to the right config file
591 fprintf(variables[i].type & VAR_HOST ? fh : f, "%s = %s\n", l, value);
597 while(l && !strcasecmp(l, "Name")) {
598 if(!check_id(value)) {
599 fprintf(stderr, "Invalid Name found in invitation.\n");
603 if(!strcmp(value, name)) {
604 fprintf(stderr, "Secondary chunk would overwrite our own host config file.\n");
608 xasprintf(&filename, "%s" SLASH "%s", hosts_dir, value);
609 f = fopen(filename, "w");
612 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
616 while((l = get_line(&p))) {
617 if(!strcmp(l, "#---------------------------------------------------------------#"))
619 int len = strcspn(l, "\t =");
620 if(len == 4 && !strncasecmp(l, "Name", 4)) {
622 value += strspn(value, "\t ");
625 value += strspn(value, "\t ");
639 // Generate our key and send a copy to the server
640 ecdsa_t *key = ecdsa_generate();
644 char *b64key = ecdsa_get_base64_public_key(key);
648 xasprintf(&filename, "%s" SLASH "ecdsa_key.priv", confbase);
649 f = fopenmask(filename, "w", 0600);
651 if(!ecdsa_write_pem_private_key(key, f)) {
652 fprintf(stderr, "Error writing private key!\n");
660 fprintf(fh, "ECDSAPublicKey = %s\n", b64key);
662 sptps_send_record(&sptps, 1, b64key, strlen(b64key));
666 rsa_t *rsa = rsa_generate(2048, 0x1001);
667 xasprintf(&filename, "%s" SLASH "rsa_key.priv", confbase);
668 f = fopenmask(filename, "w", 0600);
670 rsa_write_pem_private_key(rsa, f);
673 rsa_write_pem_public_key(rsa, fh);
681 fprintf(stderr, "Invitation succesfully accepted.\n");
682 shutdown(sock, SHUT_RDWR);
687 fprintf(stderr, "Enter a new netname: ");
688 if(!fgets(line, sizeof line, stdin)) {
689 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
692 if(!*line || *line == '\n')
695 line[strlen(line) - 1] = 0;
698 xasprintf(&newbase, CONFDIR SLASH "tinc" SLASH "%s", line);
699 if(rename(confbase, newbase)) {
700 fprintf(stderr, "Error trying to rename %s to %s: %s\n", confbase, newbase, strerror(errno));
713 static bool invitation_send(void *handle, uint8_t type, const char *data, size_t len) {
715 int result = send(sock, data, len, 0);
716 if(result == -1 && errno == EINTR)
726 static bool invitation_receive(void *handle, uint8_t type, const char *msg, uint16_t len) {
728 case SPTPS_HANDSHAKE:
729 return sptps_send_record(&sptps, 0, cookie, sizeof cookie);
732 data = xrealloc(data, datalen + len + 1);
733 memcpy(data + datalen, msg, len);
739 return finalize_join();
748 int cmd_join(int argc, char *argv[]) {
754 fprintf(stderr, "Too many arguments!\n");
758 // Make sure confbase exists and is accessible.
759 if(strcmp(confdir, confbase) && mkdir(confdir, 0755) && errno != EEXIST) {
760 fprintf(stderr, "Could not create directory %s: %s\n", confdir, strerror(errno));
764 if(mkdir(confbase, 0777) && errno != EEXIST) {
765 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
769 if(access(confbase, R_OK | W_OK | X_OK)) {
770 fprintf(stderr, "No permission to write in directory %s: %s\n", confbase, strerror(errno));
774 // If a netname or explicit configuration directory is specified, check for an existing tinc.conf.
775 if((netname || confbasegiven) && !access(tinc_conf, F_OK)) {
776 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
780 // Either read the invitation from the command line or from stdin.
784 invitation = argv[1];
787 printf("Enter invitation URL: ");
791 if(!fgets(line, sizeof line, stdin)) {
792 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
798 // Parse the invitation URL.
801 char *slash = strchr(invitation, '/');
807 if(strlen(slash) != 48)
810 char *address = invitation;
812 if(*address == '[') {
814 char *bracket = strchr(address, ']');
818 if(bracket[1] == ':')
821 port = strchr(address, ':');
829 if(!b64decode(slash, hash, 18) || !b64decode(slash + 24, cookie, 18))
832 // Generate a throw-away key for the invitation.
833 ecdsa_t *key = ecdsa_generate();
837 char *b64key = ecdsa_get_base64_public_key(key);
839 // Connect to the tinc daemon mentioned in the URL.
840 struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
844 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
846 fprintf(stderr, "Could not open socket: %s\n", strerror(errno));
850 if(connect(sock, ai->ai_addr, ai->ai_addrlen)) {
851 fprintf(stderr, "Could not connect to %s port %s: %s\n", address, port, strerror(errno));
856 fprintf(stderr, "Connected to %s port %s...\n", address, port);
858 // Tell him we have an invitation, and give him our throw-away key.
859 int len = snprintf(line, sizeof line, "0 ?%s %d.%d\n", b64key, PROT_MAJOR, PROT_MINOR);
860 if(len <= 0 || len >= sizeof line)
863 if(!sendline(sock, "0 ?%s %d.%d", b64key, PROT_MAJOR, 1)) {
864 fprintf(stderr, "Error sending request to %s port %s: %s\n", address, port, strerror(errno));
869 char hisname[4096] = "";
870 int code, hismajor, hisminor = 0;
872 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) {
873 fprintf(stderr, "Cannot read greeting from peer\n");
878 // Check if the hash of the key he gave us matches the hash in the URL.
879 char *fingerprint = line + 2;
880 digest_t *digest = digest_open_by_name("sha256", 18);
884 if(!digest_create(digest, fingerprint, strlen(fingerprint), hishash)) {
885 fprintf(stderr, "Could not create digest\n%s\n", line + 2);
888 if(memcmp(hishash, hash, 18)) {
889 fprintf(stderr, "Peer has an invalid key!\n%s\n", line + 2);
894 ecdsa_t *hiskey = ecdsa_set_base64_public_key(fingerprint);
898 // Start an SPTPS session
899 if(!sptps_start(&sptps, NULL, true, false, key, hiskey, "tinc invitation", 15, invitation_send, invitation_receive))
902 // Feed rest of input buffer to SPTPS
903 if(!sptps_receive_data(&sptps, buffer, blen))
906 while((len = recv(sock, line, sizeof line, 0))) {
910 fprintf(stderr, "Error reading data from %s port %s: %s\n", address, port, strerror(errno));
914 if(!sptps_receive_data(&sptps, line, len))
924 fprintf(stderr, "Connection closed by peer, invitation cancelled.\n");
931 fprintf(stderr, "Invalid invitation URL.\n");