2 invitation.c -- Create and accept invitations
3 Copyright (C) 2013-2022 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"
27 #include "invitation.h"
39 #include "ed25519/sha512.h"
41 int addressfamily = AF_UNSPEC;
43 static void scan_for_hostname(const char *filename, char **hostname, char **port) {
44 if(!filename || (*hostname && *port)) {
48 FILE *f = fopen(filename, "r");
54 while(fgets(line, sizeof(line), f)) {
60 p += strcspn(p, "\t =");
66 q = p + strspn(p, "\t ");
69 q += 1 + strspn(q + 1, "\t ");
73 p = q + strcspn(q, "\t ");
79 p += strspn(p, "\t ");
80 p[strcspn(p, "\t ")] = 0;
82 if(!*port && !strcasecmp(line, "Port")) {
84 } else if(!*hostname && !strcasecmp(line, "Address")) {
85 *hostname = xstrdup(q);
93 if(*hostname && *port) {
101 static char *get_my_hostname(void) {
102 char *hostname = NULL;
104 char *hostport = NULL;
105 char *name = get_my_name(false);
106 char filename[PATH_MAX] = {0};
108 // Use first Address statement in own host config file
110 snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", confbase, name);
111 scan_for_hostname(filename, &hostname, &port);
112 scan_for_hostname(tinc_conf, &hostname, &port);
122 // If that doesn't work, guess externally visible hostname
123 fprintf(stderr, "Trying to discover externally visible hostname...\n");
124 struct addrinfo *ai = str2addrinfo("tinc-vpn.org", "80", SOCK_STREAM);
125 struct addrinfo *aip = ai;
126 static const char request[] = "GET http://tinc-vpn.org/host.cgi HTTP/1.0\r\n\r\n";
129 int s = socket(aip->ai_family, aip->ai_socktype, aip->ai_protocol);
132 if(connect(s, aip->ai_addr, aip->ai_addrlen)) {
139 send(s, request, sizeof(request) - 1, 0);
140 ssize_t len = recv(s, line, sizeof(line) - 1, MSG_WAITALL);
145 if(line[len - 1] == '\n') {
149 char *p = strrchr(line, '\n');
152 hostname = xstrdup(p + 1);
171 // Check that the hostname is reasonable
173 for(char *p = hostname; *p; p++) {
174 if(isalnum((uint8_t) *p) || *p == '-' || *p == '.' || *p == ':') {
178 // If not, forget it.
187 fprintf(stderr, "Could not determine the external address or hostname. Please set Address manually.\n");
196 fprintf(stderr, "Please enter your host's external address or hostname");
199 fprintf(stderr, " [%s]", hostname);
202 fprintf(stderr, ": ");
204 if(!fgets(line, sizeof(line), stdin)) {
205 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
219 for(char *p = line; *p; p++) {
220 if(isalnum((uint8_t) *p) || *p == '-' || *p == '.') {
224 fprintf(stderr, "Invalid address or hostname.\n");
229 hostname = xstrdup(line);
234 FILE *f = fopen(filename, "a");
237 fprintf(f, "\nAddress = %s\n", hostname);
240 fprintf(stderr, "Could not append Address to %s: %s\n", filename, strerror(errno));
247 if(strchr(hostname, ':')) {
248 xasprintf(&hostport, "[%s]:%s", hostname, port);
250 xasprintf(&hostport, "%s:%s", hostname, port);
253 if(strchr(hostname, ':')) {
254 xasprintf(&hostport, "[%s]", hostname);
256 hostport = xstrdup(hostname);
265 static bool fcopy(FILE *out, const char *filename) {
266 FILE *in = fopen(filename, "r");
269 fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
276 while((len = fread(buf, 1, sizeof(buf), in))) {
277 fwrite(buf, len, 1, out);
284 int cmd_invite(int argc, char *argv[]) {
286 fprintf(stderr, "Not enough arguments!\n");
290 // Check validity of the new node's name
291 if(!check_id(argv[1])) {
292 fprintf(stderr, "Invalid name for node.\n");
297 myname = get_my_name(true);
303 // Ensure no host configuration file with that name exists
304 char filename[PATH_MAX];
305 snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", confbase, argv[1]);
307 if(!access(filename, F_OK)) {
308 fprintf(stderr, "A host config file for %s already exists!\n", argv[1]);
312 // If a daemon is running, ensure no other nodes know about this name
313 if(connect_tincd(false)) {
315 sendline(fd, "%d %d", CONTROL, REQ_DUMP_NODES);
317 while(recvline(fd, line, sizeof(line))) {
321 if(sscanf(line, "%d %d %4095s", &code, &req, node) != 3) {
325 if(!strcmp(node, argv[1])) {
331 fprintf(stderr, "A node with name %s is already known!\n", argv[1]);
336 snprintf(filename, sizeof(filename), "%s" SLASH "invitations", confbase);
338 if(mkdir(filename, 0700) && errno != EEXIST) {
339 fprintf(stderr, "Could not create directory %s: %s\n", filename, strerror(errno));
343 // Count the number of valid invitations, clean up old ones
344 DIR *dir = opendir(filename);
347 fprintf(stderr, "Could not read directory %s: %s\n", filename, strerror(errno));
354 time_t deadline = time(NULL) - 604800; // 1 week in the past
356 while((ent = readdir(dir))) {
357 if(strlen(ent->d_name) != 24) {
361 char invname[PATH_MAX];
364 if((size_t)snprintf(invname, sizeof(invname), "%s" SLASH "%s", filename, ent->d_name) >= sizeof(invname)) {
365 fprintf(stderr, "Filename too long: %s" SLASH "%s\n", filename, ent->d_name);
369 if(!stat(invname, &st)) {
370 if(deadline < st.st_mtime) {
376 fprintf(stderr, "Could not stat %s: %s\n", invname, strerror(errno));
384 fprintf(stderr, "Error while reading directory %s: %s\n", filename, strerror(errno));
389 snprintf(filename, sizeof(filename), "%s" SLASH "invitations" SLASH "ed25519_key.priv", confbase);
391 // Remove the key if there are no outstanding invitations.
396 // Create a new key if necessary.
397 FILE *f = fopen(filename, "r");
400 if(errno != ENOENT) {
401 fprintf(stderr, "Could not read %s: %s\n", filename, strerror(errno));
405 key = ecdsa_generate();
411 f = fopen(filename, "w");
414 fprintf(stderr, "Could not write %s: %s\n", filename, strerror(errno));
419 chmod(filename, 0600);
421 if(!ecdsa_write_pem_private_key(key, f)) {
422 fprintf(stderr, "Could not write ECDSA private key\n");
430 if(connect_tincd(true)) {
431 sendline(fd, "%d %d", CONTROL, REQ_RELOAD);
433 fprintf(stderr, "Could not signal the tinc daemon. Please restart or reload it manually.\n");
436 key = ecdsa_read_pem_private_key(f);
440 fprintf(stderr, "Could not read private key from %s\n", filename);
448 // Create a hash of the key.
450 char *fingerprint = ecdsa_get_base64_public_key(key);
451 sha512(fingerprint, strlen(fingerprint), hash);
452 b64encode_tinc_urlsafe(hash, hash, 18);
456 // Create a random cookie for this invitation.
458 randomize(cookie, 18);
460 // Create a filename that doesn't reveal the cookie itself
461 const size_t buflen = 18 + strlen(fingerprint);
462 uint8_t *buf = alloca(buflen);
465 memcpy(buf, cookie, 18);
466 memcpy(buf + 18, fingerprint, buflen - 18);
467 sha512(buf, buflen, cookiehash);
468 b64encode_tinc_urlsafe(cookiehash, cookiehash, 18);
472 b64encode_tinc_urlsafe(cookie, cookie, 18);
474 // Create a file containing the details of the invitation.
475 snprintf(filename, sizeof(filename), "%s" SLASH "invitations" SLASH "%s", confbase, cookiehash);
476 int ifd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
479 fprintf(stderr, "Could not create invitation file %s: %s\n", filename, strerror(errno));
483 f = fdopen(ifd, "w");
489 // Get the local address
490 char *address = get_my_hostname();
492 // Fill in the details.
493 fprintf(f, "Name = %s\n", argv[1]);
495 if(check_netname(netname, true)) {
496 fprintf(f, "NetName = %s\n", netname);
499 fprintf(f, "ConnectTo = %s\n", myname);
501 // Copy Broadcast and Mode
502 FILE *tc = fopen(tinc_conf, "r");
507 while(fgets(buf, sizeof(buf), tc)) {
508 if((!strncasecmp(buf, "Mode", 4) && strchr(" \t=", buf[4]))
509 || (!strncasecmp(buf, "Broadcast", 9) && strchr(" \t=", buf[9]))) {
512 // Make sure there is a newline character.
513 if(!strchr(buf, '\n')) {
522 fprintf(f, "#---------------------------------------------------------------#\n");
523 fprintf(f, "Name = %s\n", myname);
525 char filename2[PATH_MAX];
526 snprintf(filename2, sizeof(filename2), "%s" SLASH "hosts" SLASH "%s", confbase, myname);
530 // Create an URL from the local address, key hash and cookie
532 xasprintf(&url, "%s/%s%s", address, hash, cookie);
534 // Call the inviation-created script
536 environment_init(&env);
537 environment_add(&env, "NODE=%s", argv[1]);
538 environment_add(&env, "INVITATION_FILE=%s", filename);
539 environment_add(&env, "INVITATION_URL=%s", url);
540 execute_script("invitation-created", &env);
541 environment_exit(&env);
551 static char cookie[18], hash[18];
552 static sptps_t sptps;
554 static size_t datalen;
555 static bool success = false;
557 static char *get_line(char *line, size_t linelen, const char **data) {
558 if(!data || !*data) {
567 const char *end = strchr(*data, '\n');
568 size_t len = end ? (size_t)(end - *data) : strlen(*data);
571 fprintf(stderr, "Maximum line length exceeded!\n");
575 if(len && !isprint((uint8_t) **data)) {
579 memcpy(line, *data, len);
591 static char *get_value(const char *data, const char *var) {
592 static char buf[1024];
594 char *line = get_line(buf, sizeof(buf), &data);
600 char *sep = line + strcspn(line, " \t=");
601 char *val = sep + strspn(sep, " \t");
604 val += 1 + strspn(val + 1, " \t");
609 if(strcasecmp(line, var)) {
616 static char *grep(const char *data, const char *var) {
617 static char value[1024];
619 const char *p = data;
620 size_t varlen = strlen(var);
622 // Skip all lines not starting with var
623 while(strncasecmp(p, var, varlen) || !strchr(" \t=", p[varlen])) {
638 p += strspn(p, " \t");
641 p += 1 + strspn(p + 1, " \t");
644 const char *e = strchr(p, '\n');
650 if((size_t)(e - p) >= sizeof(value)) {
651 fprintf(stderr, "Maximum line length exceeded!\n");
655 memcpy(value, p, e - p);
660 static bool finalize_join(void) {
661 const char *name = get_value(data, "Name");
664 fprintf(stderr, "No Name found in invitation!\n");
668 if(!check_id(name)) {
669 fprintf(stderr, "Invalid Name found in invitation!\n");
674 netname = xstrdup(grep(data, "NetName"));
676 if(netname && !check_netname(netname, true)) {
677 fprintf(stderr, "Unsafe NetName found in invitation!\n");
682 bool ask_netname = false;
683 char temp_netname[32];
697 xasprintf(&tinc_conf, "%s" SLASH "tinc.conf", confbase);
698 xasprintf(&hosts_dir, "%s" SLASH "hosts", confbase);
700 if(!access(tinc_conf, F_OK)) {
701 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
707 // Generate a random netname, ask for a better one later.
709 snprintf(temp_netname, sizeof(temp_netname), "join_%x", prng(UINT32_MAX));
710 netname = temp_netname;
714 if(mkdir(confbase, 0777) && errno != EEXIST) {
715 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
719 if(mkdir(hosts_dir, 0777) && errno != EEXIST) {
720 fprintf(stderr, "Could not create directory %s: %s\n", hosts_dir, strerror(errno));
724 FILE *f = fopen(tinc_conf, "w");
727 fprintf(stderr, "Could not create file %s: %s\n", tinc_conf, strerror(errno));
731 fprintf(f, "Name = %s\n", name);
733 char filename[PATH_MAX];
734 snprintf(filename, sizeof(filename), "%s" SLASH "%s", hosts_dir, name);
735 FILE *fh = fopen(filename, "w");
738 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
743 snprintf(filename, sizeof(filename), "%s" SLASH "invitation-data", confbase);
744 FILE *finv = fopen(filename, "w");
746 if(!finv || fwrite(data, datalen, 1, finv) != 1) {
747 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
756 snprintf(filename, sizeof(filename), "%s" SLASH "tinc-up.invitation", confbase);
757 FILE *fup = fopen(filename, "w");
760 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
766 ifconfig_header(fup);
768 // Filter first chunk on approved keywords, split between tinc.conf and hosts/Name
769 // Generate a tinc-up script from Ifconfig and Route keywords.
770 // Other chunks go unfiltered to their respective host config files
771 const char *p = data;
774 static char line[1024];
776 while((l = get_line(line, sizeof(line), &p))) {
782 // Split line into variable and value
783 size_t len = strcspn(l, "\t =");
785 value += strspn(value, "\t ");
789 value += strspn(value, "\t ");
794 // Ignore lines with empty variable names
800 if(!strcasecmp(l, "Name")) {
801 if(strcmp(value, name)) {
806 } else if(!strcasecmp(l, "NetName")) {
810 // Check the list of known variables
814 for(i = 0; variables[i].name; i++) {
815 if(strcasecmp(l, variables[i].name)) {
823 // Handle Ifconfig and Route statements
825 if(!strcasecmp(l, "Ifconfig")) {
826 if(!strcasecmp(value, "dhcp")) {
828 } else if(!strcasecmp(value, "dhcp6")) {
830 } else if(!strcasecmp(value, "slaac")) {
833 ifconfig_address(fup, value);
837 } else if(!strcasecmp(l, "Route")) {
838 ifconfig_route(fup, value);
843 // Ignore unknown and unsafe variables
845 fprintf(stderr, "Ignoring unknown variable '%s' in invitation.\n", l);
847 } else if(!(variables[i].type & VAR_SAFE)) {
849 fprintf(stderr, "Warning: unsafe variable '%s' in invitation.\n", l);
851 fprintf(stderr, "Ignoring unsafe variable '%s' in invitation.\n", l);
856 // Copy the safe variable to the right config file
857 fprintf((variables[i].type & VAR_HOST) ? fh : f, "%s = %s\n", l, value);
861 bool valid_tinc_up = ifconfig_footer(fup);
864 while(l && !strcasecmp(l, "Name")) {
865 if(!check_id(value)) {
866 fprintf(stderr, "Invalid Name found in invitation.\n");
870 if(!strcmp(value, name)) {
871 fprintf(stderr, "Secondary chunk would overwrite our own host config file.\n");
875 snprintf(filename, sizeof(filename), "%s" SLASH "%s", hosts_dir, value);
876 f = fopen(filename, "w");
879 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
883 while((l = get_line(line, sizeof(line), &p))) {
884 if(!strcmp(l, "#---------------------------------------------------------------#")) {
888 size_t len = strcspn(l, "\t =");
890 if(len == 4 && !strncasecmp(l, "Name", 4)) {
892 value += strspn(value, "\t ");
896 value += strspn(value, "\t ");
910 // Generate our key and send a copy to the server
911 ecdsa_t *key = ecdsa_generate();
917 char *b64key = ecdsa_get_base64_public_key(key);
923 snprintf(filename, sizeof(filename), "%s" SLASH "ed25519_key.priv", confbase);
924 f = fopenmask(filename, "w", 0600);
930 if(!ecdsa_write_pem_private_key(key, f)) {
931 fprintf(stderr, "Error writing private key!\n");
939 fprintf(fh, "Ed25519PublicKey = %s\n", b64key);
941 sptps_send_record(&sptps, 1, b64key, strlen(b64key));
945 #ifndef DISABLE_LEGACY
946 rsa_t *rsa = rsa_generate(2048, 0x1001);
947 snprintf(filename, sizeof(filename), "%s" SLASH "rsa_key.priv", confbase);
948 f = fopenmask(filename, "w", 0600);
950 if(!f || !rsa_write_pem_private_key(rsa, f)) {
951 fprintf(stderr, "Could not write private RSA key\n");
952 } else if(!rsa_write_pem_public_key(rsa, fh)) {
953 fprintf(stderr, "Could not write public RSA key\n");
967 if(ask_netname && tty) {
968 fprintf(stderr, "Enter a new netname: ");
970 if(!fgets(line, sizeof(line), stdin)) {
971 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
975 if(!*line || *line == '\n') {
979 line[strlen(line) - 1] = 0;
981 char newbase[PATH_MAX];
983 if((size_t)snprintf(newbase, sizeof(newbase), CONFDIR SLASH "tinc" SLASH "%s", line) >= sizeof(newbase)) {
984 fprintf(stderr, "Filename too long: " CONFDIR SLASH "tinc" SLASH "%s\n", line);
988 if(rename(confbase, newbase)) {
989 fprintf(stderr, "Error trying to rename %s to %s: %s\n", confbase, newbase, strerror(errno));
997 char filename2[PATH_MAX];
998 snprintf(filename, sizeof(filename), "%s" SLASH "tinc-up.invitation", confbase);
1001 snprintf(filename2, sizeof(filename2), "%s" SLASH "tinc-up.bat", confbase);
1003 snprintf(filename2, sizeof(filename2), "%s" SLASH "tinc-up", confbase);
1008 FILE *fup = fopen(filename, "r");
1011 fprintf(stderr, "\nPlease review the following tinc-up script:\n\n");
1015 while(fgets(buf, sizeof(buf), fup)) {
1024 fprintf(stderr, "\nDo you want to use this script [y]es/[n]o/[e]dit? ");
1025 response = tolower(getchar());
1026 } while(!strchr("yne", response));
1028 fprintf(stderr, "\n");
1030 if(response == 'e') {
1032 #ifndef HAVE_WINDOWS
1033 const char *editor = getenv("VISUAL");
1036 editor = getenv("EDITOR");
1043 xasprintf(&command, "\"%s\" \"%s\"", editor, filename);
1045 xasprintf(&command, "edit \"%s\"", filename);
1048 if(system(command)) {
1057 if(response == 'y') {
1058 rename(filename, filename2);
1059 chmod(filename2, 0755);
1060 fprintf(stderr, "tinc-up enabled.\n");
1062 fprintf(stderr, "tinc-up has been left disabled.\n");
1067 rename(filename, filename2);
1068 chmod(filename2, 0755);
1069 fprintf(stderr, "tinc-up enabled.\n");
1071 fprintf(stderr, "A tinc-up script was generated, but has been left disabled.\n");
1075 // A placeholder was generated.
1076 rename(filename, filename2);
1077 chmod(filename2, 0755);
1080 fprintf(stderr, "Configuration stored in: %s\n", confbase);
1086 static bool invitation_send(void *handle, uint8_t type, const void *vdata, size_t len) {
1089 const char *data = vdata;
1092 ssize_t result = send(sock, data, len, 0);
1094 if(result == -1 && sockwouldblock(sockerrno)) {
1096 } else if(result <= 0) {
1107 static bool invitation_receive(void *handle, uint8_t type, const void *msg, uint16_t len) {
1111 case SPTPS_HANDSHAKE:
1112 return sptps_send_record(&sptps, 0, cookie, sizeof(cookie));
1115 data = xrealloc(data, datalen + len + 1);
1116 memcpy(data + datalen, msg, len);
1122 return finalize_join();
1125 fprintf(stderr, "Invitation successfully accepted.\n");
1126 shutdown(sock, SHUT_RDWR);
1137 int cmd_join(int argc, char *argv[]) {
1143 fprintf(stderr, "Too many arguments!\n");
1147 // Make sure confbase exists and is accessible.
1148 if(!confbase_given && mkdir(confdir, 0755) && errno != EEXIST) {
1149 fprintf(stderr, "Could not create directory %s: %s\n", confdir, strerror(errno));
1153 if(mkdir(confbase, 0777) && errno != EEXIST) {
1154 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
1158 if(access(confbase, R_OK | W_OK | X_OK)) {
1159 fprintf(stderr, "No permission to write in directory %s: %s\n", confbase, strerror(errno));
1163 // If a netname or explicit configuration directory is specified, check for an existing tinc.conf.
1164 if((netname || confbasegiven) && !access(tinc_conf, F_OK)) {
1165 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
1169 // Either read the invitation from the command line or from stdin.
1173 invitation = argv[1];
1176 fprintf(stderr, "Enter invitation URL: ");
1181 if(!fgets(line, sizeof(line), stdin)) {
1182 fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
1189 // Parse the invitation URL.
1192 char *slash = strchr(invitation, '/');
1200 if(strlen(slash) != 48) {
1204 char *address = invitation;
1207 if(*address == '[') {
1209 char *bracket = strchr(address, ']');
1217 if(bracket[1] == ':') {
1221 port = strchr(address, ':');
1228 if(!port || !*port) {
1229 static char default_port[] = "655";
1230 port = default_port;
1233 if(!b64decode_tinc(slash, hash, 24) || !b64decode_tinc(slash + 24, cookie, 24)) {
1237 // Generate a throw-away key for the invitation.
1238 ecdsa_t *key = ecdsa_generate();
1244 char *b64key = ecdsa_get_base64_public_key(key);
1246 // Connect to the tinc daemon mentioned in the URL.
1247 struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
1255 struct addrinfo *aip = NULL;
1271 sock = socket(aip->ai_family, aip->ai_socktype, aip->ai_protocol);
1274 fprintf(stderr, "Could not open socket: %s\n", strerror(errno));
1278 if(connect(sock, aip->ai_addr, aip->ai_addrlen)) {
1279 char *addrstr, *portstr;
1280 sockaddr2str((sockaddr_t *)aip->ai_addr, &addrstr, &portstr);
1281 fprintf(stderr, "Could not connect to %s port %s: %s\n", addrstr, portstr, strerror(errno));
1288 fprintf(stderr, "Connected to %s port %s...\n", address, port);
1290 // Tell him we have an invitation, and give him our throw-away key.
1291 ssize_t len = snprintf(line, sizeof(line), "0 ?%s %d.%d\n", b64key, PROT_MAJOR, PROT_MINOR);
1293 if(len <= 0 || (size_t)len >= sizeof(line)) {
1297 if(!sendline(sock, "0 ?%s %d.%d", b64key, PROT_MAJOR, 1)) {
1298 fprintf(stderr, "Error sending request to %s port %s: %s\n", address, port, strerror(errno));
1303 char hisname[4096] = "";
1304 int code, hismajor, hisminor = 0;
1306 if(!recvline(sock, line, sizeof(line)) || sscanf(line, "%d %4095s %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) {
1307 fprintf(stderr, "Cannot read greeting from peer\n");
1319 // Check if the hash of the key he gave us matches the hash in the URL.
1320 char *fingerprint = line + 2;
1323 if(sha512(fingerprint, strlen(fingerprint), hishash)) {
1324 fprintf(stderr, "Could not create digest\n%s\n", line + 2);
1329 if(memcmp(hishash, hash, 18)) {
1330 fprintf(stderr, "Peer has an invalid key!\n%s\n", line + 2);
1336 ecdsa_t *hiskey = ecdsa_set_base64_public_key(fingerprint);
1343 // Start an SPTPS session
1344 if(!sptps_start(&sptps, NULL, true, false, key, hiskey, "tinc invitation", 15, invitation_send, invitation_receive)) {
1350 // Feed rest of input buffer to SPTPS
1351 if(!sptps_receive_data(&sptps, buffer, blen)) {
1356 while((len = recv(sock, line, sizeof(line), 0))) {
1358 if(sockwouldblock(sockerrno)) {
1364 // If socket has been shut down, recv() on Windows returns -1 and sets sockerrno
1365 // to WSAESHUTDOWN, while on UNIX-like operating systems recv() returns 0, so we
1366 // have to do an explicit check here.
1367 if(sockshutdown(sockerrno)) {
1372 fprintf(stderr, "Error reading data from %s port %s: %s\n", address, port, sockstrerror(sockerrno));
1380 size_t done = sptps_receive_data(&sptps, p, len);
1387 len -= (ssize_t) done;
1399 fprintf(stderr, "Invitation cancelled.\n");
1406 fprintf(stderr, "Invalid invitation URL.\n");