2 invitation.c -- Create and accept invitations
3 Copyright (C) 2013-2014 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.
147 fprintf(stderr, "Could not determine the external address or hostname. Please set Address manually.\n");
154 fprintf(stderr, "Please enter your host's external address or hostname");
156 fprintf(stderr, " [%s]", hostname);
157 fprintf(stderr, ": ");
159 if(!fgets(line, sizeof line, stdin)) {
160 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
172 for(char *p = line; *p; p++) {
173 if(isalnum(*p) || *p == '-' || *p == '.')
175 fprintf(stderr, "Invalid address or hostname.\n");
180 hostname = xstrdup(line);
184 FILE *f = fopen(filename, "a");
186 fprintf(f, "\nAddress = %s\n", hostname);
189 fprintf(stderr, "Could not append Address to %s: %s\n", filename, strerror(errno));
195 if(strchr(hostname, ':'))
196 xasprintf(&hostport, "[%s]:%s", hostname, port);
198 xasprintf(&hostport, "%s:%s", hostname, port);
200 if(strchr(hostname, ':'))
201 xasprintf(&hostport, "[%s]", hostname);
203 hostport = xstrdup(hostname);
212 static bool fcopy(FILE *out, const char *filename) {
213 FILE *in = fopen(filename, "r");
215 fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
221 while((len = fread(buf, 1, sizeof buf, in)))
222 fwrite(buf, len, 1, out);
227 int cmd_invite(int argc, char *argv[]) {
229 fprintf(stderr, "Not enough arguments!\n");
233 // Check validity of the new node's name
234 if(!check_id(argv[1])) {
235 fprintf(stderr, "Invalid name for node.\n");
239 char *myname = get_my_name(true);
243 // Ensure no host configuration file with that name exists
244 char *filename = NULL;
245 xasprintf(&filename, "%s" SLASH "hosts" SLASH "%s", confbase, argv[1]);
246 if(!access(filename, F_OK)) {
248 fprintf(stderr, "A host config file for %s already exists!\n", argv[1]);
253 // If a daemon is running, ensure no other nodes know about this name
255 if(connect_tincd(false)) {
256 sendline(fd, "%d %d", CONTROL, REQ_DUMP_NODES);
258 while(recvline(fd, line, sizeof line)) {
261 if(sscanf(line, "%d %d %s", &code, &req, node) != 3)
263 if(!strcmp(node, argv[1]))
268 fprintf(stderr, "A node with name %s is already known!\n", argv[1]);
275 xasprintf(&filename, "%s" SLASH "invitations", confbase);
276 if(mkdir(filename, 0700) && errno != EEXIST) {
277 fprintf(stderr, "Could not create directory %s: %s\n", filename, strerror(errno));
282 // Count the number of valid invitations, clean up old ones
283 DIR *dir = opendir(filename);
285 fprintf(stderr, "Could not read directory %s: %s\n", filename, strerror(errno));
293 time_t deadline = time(NULL) - 604800; // 1 week in the past
295 while((ent = readdir(dir))) {
296 if(strlen(ent->d_name) != 24)
300 xasprintf(&invname, "%s" SLASH "%s", filename, ent->d_name);
301 if(!stat(invname, &st)) {
302 if(deadline < st.st_mtime)
307 fprintf(stderr, "Could not stat %s: %s\n", invname, strerror(errno));
314 fprintf(stderr, "Error while reading directory %s: %s\n", filename, strerror(errno));
324 xasprintf(&filename, "%s" SLASH "invitations" SLASH "ed25519_key.priv", confbase);
326 // Remove the key if there are no outstanding invitations.
330 // Create a new key if necessary.
331 FILE *f = fopen(filename, "r");
333 if(errno != ENOENT) {
334 fprintf(stderr, "Could not read %s: %s\n", filename, strerror(errno));
339 key = ecdsa_generate();
344 f = fopen(filename, "w");
346 fprintf(stderr, "Could not write %s: %s\n", filename, strerror(errno));
350 chmod(filename, 0600);
351 ecdsa_write_pem_private_key(key, f);
354 if(connect_tincd(false))
355 sendline(fd, "%d %d", CONTROL, REQ_RELOAD);
357 key = ecdsa_read_pem_private_key(f);
360 fprintf(stderr, "Could not read private key from %s\n", filename);
367 // Create a hash of the key.
368 char *fingerprint = ecdsa_get_base64_public_key(key);
369 digest_t *digest = digest_open_by_name("sha256", 18);
372 digest_create(digest, fingerprint, strlen(fingerprint), hash);
373 b64encode_urlsafe(hash, hash, 18);
375 // Create a random cookie for this invitation.
377 randomize(cookie, 18);
379 // Create a filename that doesn't reveal the cookie itself
380 char buf[18 + strlen(fingerprint)];
382 memcpy(buf, cookie, 18);
383 memcpy(buf + 18, fingerprint, sizeof buf - 18);
384 digest_create(digest, buf, sizeof buf, cookiehash);
385 b64encode_urlsafe(cookiehash, cookiehash, 18);
387 b64encode_urlsafe(cookie, cookie, 18);
389 // Create a file containing the details of the invitation.
390 xasprintf(&filename, "%s" SLASH "invitations" SLASH "%s", confbase, cookiehash);
391 int ifd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
393 fprintf(stderr, "Could not create invitation file %s: %s\n", filename, strerror(errno));
397 f = fdopen(ifd, "w");
401 // Get the local address
402 char *address = get_my_hostname();
404 // Fill in the details.
405 fprintf(f, "Name = %s\n", argv[1]);
407 fprintf(f, "NetName = %s\n", netname);
408 fprintf(f, "ConnectTo = %s\n", myname);
410 // Copy Broadcast and Mode
411 FILE *tc = fopen(tinc_conf, "r");
414 while(fgets(buf, sizeof buf, tc)) {
415 if((!strncasecmp(buf, "Mode", 4) && strchr(" \t=", buf[4]))
416 || (!strncasecmp(buf, "Broadcast", 9) && strchr(" \t=", buf[9]))) {
418 // Make sure there is a newline character.
419 if(!strchr(buf, '\n'))
426 fprintf(f, "#---------------------------------------------------------------#\n");
427 fprintf(f, "Name = %s\n", myname);
430 xasprintf(&filename2, "%s" SLASH "hosts" SLASH "%s", confbase, myname);
435 // Create an URL from the local address, key hash and cookie
437 xasprintf(&url, "%s/%s%s", address, hash, cookie);
439 // Call the inviation-created script
441 xasprintf(&envp[0], "NAME=%s", myname);
442 xasprintf(&envp[1], "NETNAME=%s", netname);
443 xasprintf(&envp[2], "NODE=%s", argv[1]);
444 xasprintf(&envp[3], "INVITATION_FILE=%s", filename);
445 xasprintf(&envp[4], "INVITATION_URL=%s", url);
446 execute_script("invitation-created", envp);
447 for(int i = 0; i < 6 && envp[i]; i++)
459 static char cookie[18];
460 static sptps_t sptps;
462 static size_t datalen;
463 static bool success = false;
465 static char cookie[18], hash[18];
467 static char *get_line(const char **data) {
476 static char line[1024];
477 const char *end = strchr(*data, '\n');
478 size_t len = end ? end - *data : strlen(*data);
479 if(len >= sizeof line) {
480 fprintf(stderr, "Maximum line length exceeded!\n");
483 if(len && !isprint(**data))
486 memcpy(line, *data, len);
497 static char *get_value(const char *data, const char *var) {
498 char *line = get_line(&data);
502 char *sep = line + strcspn(line, " \t=");
503 char *val = sep + strspn(sep, " \t");
505 val += 1 + strspn(val + 1, " \t");
507 if(strcasecmp(line, var))
512 static char *grep(const char *data, const char *var) {
513 static char value[1024];
515 const char *p = data;
516 int varlen = strlen(var);
518 // Skip all lines not starting with var
519 while(strncasecmp(p, var, varlen) || !strchr(" \t=", p[varlen])) {
531 p += strspn(p, " \t");
533 p += 1 + strspn(p + 1, " \t");
535 const char *e = strchr(p, '\n');
539 if(e - p >= sizeof value) {
540 fprintf(stderr, "Maximum line length exceeded!\n");
544 memcpy(value, p, e - p);
549 static bool finalize_join(void) {
550 char *name = xstrdup(get_value(data, "Name"));
552 fprintf(stderr, "No Name found in invitation!\n");
556 if(!check_id(name)) {
557 fprintf(stderr, "Invalid Name found in invitation: %s!\n", name);
562 netname = grep(data, "NetName");
564 bool ask_netname = false;
565 char temp_netname[32];
578 xasprintf(&tinc_conf, "%s" SLASH "tinc.conf", confbase);
579 xasprintf(&hosts_dir, "%s" SLASH "hosts", confbase);
581 if(!access(tinc_conf, F_OK)) {
582 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
586 // Generate a random netname, ask for a better one later.
588 snprintf(temp_netname, sizeof temp_netname, "join_%x", rand());
589 netname = temp_netname;
593 if(mkdir(confbase, 0777) && errno != EEXIST) {
594 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
598 if(mkdir(hosts_dir, 0777) && errno != EEXIST) {
599 fprintf(stderr, "Could not create directory %s: %s\n", hosts_dir, strerror(errno));
603 FILE *f = fopen(tinc_conf, "w");
605 fprintf(stderr, "Could not create file %s: %s\n", tinc_conf, strerror(errno));
609 fprintf(f, "Name = %s\n", name);
612 xasprintf(&filename, "%s" SLASH "%s", hosts_dir, name);
613 FILE *fh = fopen(filename, "w");
615 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
620 // Filter first chunk on approved keywords, split between tinc.conf and hosts/Name
621 // Other chunks go unfiltered to their respective host config files
622 const char *p = data;
625 while((l = get_line(&p))) {
630 // Split line into variable and value
631 int len = strcspn(l, "\t =");
633 value += strspn(value, "\t ");
636 value += strspn(value, "\t ");
641 if(!strcasecmp(l, "Name"))
642 if(strcmp(value, name))
646 else if(!strcasecmp(l, "NetName"))
649 // Check the list of known variables
652 for(i = 0; variables[i].name; i++) {
653 if(strcasecmp(l, variables[i].name))
659 // Ignore unknown and unsafe variables
661 fprintf(stderr, "Ignoring unknown variable '%s' in invitation.\n", l);
663 } else if(!(variables[i].type & VAR_SAFE)) {
664 fprintf(stderr, "Ignoring unsafe variable '%s' in invitation.\n", l);
668 // Copy the safe variable to the right config file
669 fprintf(variables[i].type & VAR_HOST ? fh : f, "%s = %s\n", l, value);
675 while(l && !strcasecmp(l, "Name")) {
676 if(!check_id(value)) {
677 fprintf(stderr, "Invalid Name found in invitation.\n");
681 if(!strcmp(value, name)) {
682 fprintf(stderr, "Secondary chunk would overwrite our own host config file.\n");
686 xasprintf(&filename, "%s" SLASH "%s", hosts_dir, value);
687 f = fopen(filename, "w");
690 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
694 while((l = get_line(&p))) {
695 if(!strcmp(l, "#---------------------------------------------------------------#"))
697 int len = strcspn(l, "\t =");
698 if(len == 4 && !strncasecmp(l, "Name", 4)) {
700 value += strspn(value, "\t ");
703 value += strspn(value, "\t ");
717 // Generate our key and send a copy to the server
718 ecdsa_t *key = ecdsa_generate();
722 char *b64key = ecdsa_get_base64_public_key(key);
726 xasprintf(&filename, "%s" SLASH "ed25519_key.priv", confbase);
727 f = fopenmask(filename, "w", 0600);
729 if(!ecdsa_write_pem_private_key(key, f)) {
730 fprintf(stderr, "Error writing private key!\n");
738 fprintf(fh, "Ed25519PublicKey = %s\n", b64key);
740 sptps_send_record(&sptps, 1, b64key, strlen(b64key));
744 rsa_t *rsa = rsa_generate(2048, 0x1001);
745 xasprintf(&filename, "%s" SLASH "rsa_key.priv", confbase);
746 f = fopenmask(filename, "w", 0600);
748 rsa_write_pem_private_key(rsa, f);
751 rsa_write_pem_public_key(rsa, fh);
760 if(ask_netname && tty) {
761 fprintf(stderr, "Enter a new netname: ");
762 if(!fgets(line, sizeof line, stdin)) {
763 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
766 if(!*line || *line == '\n')
769 line[strlen(line) - 1] = 0;
772 xasprintf(&newbase, CONFDIR SLASH "tinc" SLASH "%s", line);
773 if(rename(confbase, newbase)) {
774 fprintf(stderr, "Error trying to rename %s to %s: %s\n", confbase, newbase, strerror(errno));
784 fprintf(stderr, "Configuration stored in: %s\n", confbase);
790 static bool invitation_send(void *handle, uint8_t type, const char *data, size_t len) {
792 int result = send(sock, data, len, 0);
793 if(result == -1 && errno == EINTR)
803 static bool invitation_receive(void *handle, uint8_t type, const char *msg, uint16_t len) {
805 case SPTPS_HANDSHAKE:
806 return sptps_send_record(&sptps, 0, cookie, sizeof cookie);
809 data = xrealloc(data, datalen + len + 1);
810 memcpy(data + datalen, msg, len);
816 return finalize_join();
819 fprintf(stderr, "Invitation succesfully accepted.\n");
820 shutdown(sock, SHUT_RDWR);
831 int cmd_join(int argc, char *argv[]) {
837 fprintf(stderr, "Too many arguments!\n");
841 // Make sure confbase exists and is accessible.
842 if(!confbase_given && mkdir(confdir, 0755) && errno != EEXIST) {
843 fprintf(stderr, "Could not create directory %s: %s\n", confdir, strerror(errno));
847 if(mkdir(confbase, 0777) && errno != EEXIST) {
848 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
852 if(access(confbase, R_OK | W_OK | X_OK)) {
853 fprintf(stderr, "No permission to write in directory %s: %s\n", confbase, strerror(errno));
857 // If a netname or explicit configuration directory is specified, check for an existing tinc.conf.
858 if((netname || confbasegiven) && !access(tinc_conf, F_OK)) {
859 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
863 // Either read the invitation from the command line or from stdin.
867 invitation = argv[1];
870 fprintf(stderr, "Enter invitation URL: ");
872 if(!fgets(line, sizeof line, stdin)) {
873 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
879 // Parse the invitation URL.
882 char *slash = strchr(invitation, '/');
888 if(strlen(slash) != 48)
891 char *address = invitation;
893 if(*address == '[') {
895 char *bracket = strchr(address, ']');
899 if(bracket[1] == ':')
902 port = strchr(address, ':');
910 if(!b64decode(slash, hash, 24) || !b64decode(slash + 24, cookie, 24))
913 // Generate a throw-away key for the invitation.
914 ecdsa_t *key = ecdsa_generate();
918 char *b64key = ecdsa_get_base64_public_key(key);
920 // Connect to the tinc daemon mentioned in the URL.
921 struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
925 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
927 fprintf(stderr, "Could not open socket: %s\n", strerror(errno));
931 if(connect(sock, ai->ai_addr, ai->ai_addrlen)) {
932 fprintf(stderr, "Could not connect to %s port %s: %s\n", address, port, strerror(errno));
937 fprintf(stderr, "Connected to %s port %s...\n", address, port);
939 // Tell him we have an invitation, and give him our throw-away key.
940 int len = snprintf(line, sizeof line, "0 ?%s %d.%d\n", b64key, PROT_MAJOR, PROT_MINOR);
941 if(len <= 0 || len >= sizeof line)
944 if(!sendline(sock, "0 ?%s %d.%d", b64key, PROT_MAJOR, 1)) {
945 fprintf(stderr, "Error sending request to %s port %s: %s\n", address, port, strerror(errno));
950 char hisname[4096] = "";
951 int code, hismajor, hisminor = 0;
953 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) {
954 fprintf(stderr, "Cannot read greeting from peer\n");
959 // Check if the hash of the key he gave us matches the hash in the URL.
960 char *fingerprint = line + 2;
961 digest_t *digest = digest_open_by_name("sha256", 18);
965 if(!digest_create(digest, fingerprint, strlen(fingerprint), hishash)) {
966 fprintf(stderr, "Could not create digest\n%s\n", line + 2);
969 if(memcmp(hishash, hash, 18)) {
970 fprintf(stderr, "Peer has an invalid key!\n%s\n", line + 2);
975 ecdsa_t *hiskey = ecdsa_set_base64_public_key(fingerprint);
979 // Start an SPTPS session
980 if(!sptps_start(&sptps, NULL, true, false, key, hiskey, "tinc invitation", 15, invitation_send, invitation_receive))
983 // Feed rest of input buffer to SPTPS
984 if(!sptps_receive_data(&sptps, buffer, blen))
987 while((len = recv(sock, line, sizeof line, 0))) {
991 fprintf(stderr, "Error reading data from %s port %s: %s\n", address, port, strerror(errno));
995 if(!sptps_receive_data(&sptps, line, len))
1005 fprintf(stderr, "Connection closed by peer, invitation cancelled.\n");
1012 fprintf(stderr, "Invalid invitation URL.\n");