2 protocol_auth.c -- handle the meta-protocol, authentication
3 Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
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.
23 #include "connection.h"
41 ecdsa_t *invitation_key = NULL;
43 static bool send_proxyrequest(connection_t *c) {
49 sockaddr2str(&c->address, &host, &port);
50 send_request(c, "CONNECT %s:%s HTTP/1.1\r\n\r", host, port);
56 if(c->address.sa.sa_family != AF_INET) {
57 logger(DEBUG_ALWAYS, LOG_ERR, "Cannot connect to an IPv6 host through a SOCKS 4 proxy!");
60 char s4req[9 + (proxyuser ? strlen(proxyuser) : 0)];
63 memcpy(s4req + 2, &c->address.in.sin_port, 2);
64 memcpy(s4req + 4, &c->address.in.sin_addr, 4);
66 memcpy(s4req + 8, proxyuser, strlen(proxyuser));
67 s4req[sizeof s4req - 1] = 0;
69 return send_meta(c, s4req, sizeof s4req);
72 int len = 3 + 6 + (c->address.sa.sa_family == AF_INET ? 4 : 16);
75 len += 3 + strlen(proxyuser) + strlen(proxypass);
83 s5req[i++] = strlen(proxyuser);
84 memcpy(s5req + i, proxyuser, strlen(proxyuser));
85 i += strlen(proxyuser);
86 s5req[i++] = strlen(proxypass);
87 memcpy(s5req + i, proxypass, strlen(proxypass));
88 i += strlen(proxypass);
96 if(c->address.sa.sa_family == AF_INET) {
98 memcpy(s5req + i, &c->address.in.sin_addr, 4);
100 memcpy(s5req + i, &c->address.in.sin_port, 2);
103 } else if(c->address.sa.sa_family == AF_INET6) {
105 memcpy(s5req + i, &c->address.in6.sin6_addr, 16);
107 memcpy(s5req + i, &c->address.in6.sin6_port, 2);
111 logger(DEBUG_ALWAYS, LOG_ERR, "Address family %hx not supported for SOCKS 5 proxies!", c->address.sa.sa_family);
116 return send_meta(c, s5req, sizeof s5req);
119 logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type not implemented yet");
124 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown proxy type");
129 bool send_id(connection_t *c) {
130 gettimeofday(&c->start, NULL);
132 int minor = myself->connection->protocol_minor;
134 if(proxytype && c->outgoing)
135 if(!send_proxyrequest(c))
138 return send_request(c, "%d %s %d.%d", ID, myself->connection->name, myself->connection->protocol_major, minor);
141 static bool finalize_invitation(connection_t *c, const char *data, uint16_t len) {
142 if(strchr(data, '\n')) {
143 logger(DEBUG_ALWAYS, LOG_ERR, "Received invalid key from invited node %s (%s)!\n", c->name, c->hostname);
147 // Create a new host config file
148 char filename[PATH_MAX];
149 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", confbase, c->name);
150 if(!access(filename, F_OK)) {
151 logger(DEBUG_ALWAYS, LOG_ERR, "Host config file for %s (%s) already exists!\n", c->name, c->hostname);
155 FILE *f = fopen(filename, "w");
157 logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to create %s: %s\n", filename, strerror(errno));
161 fprintf(f, "ECDSAPublicKey = %s\n", data);
164 logger(DEBUG_CONNECTIONS, LOG_INFO, "Key succesfully received from %s (%s)", c->name, c->hostname);
166 //TODO: callback to application to inform of an accepted invitation
168 sptps_send_record(&c->sptps, 2, data, 0);
172 static bool receive_invitation_sptps(void *handle, uint8_t type, const char *data, uint16_t len) {
173 connection_t *c = handle;
178 if(type == 1 && c->status.invitation_used)
179 return finalize_invitation(c, data, len);
181 if(type != 0 || len != 18 || c->status.invitation_used)
184 // Recover the filename from the cookie and the key
185 digest_t *digest = digest_open_by_name("sha256", 18);
188 char *fingerprint = ecdsa_get_base64_public_key(invitation_key);
189 char hashbuf[18 + strlen(fingerprint)];
191 memcpy(hashbuf, data, 18);
192 memcpy(hashbuf + 18, fingerprint, sizeof hashbuf - 18);
193 digest_create(digest, hashbuf, sizeof hashbuf, cookie);
194 b64encode_urlsafe(cookie, cookie, 18);
195 digest_close(digest);
198 char filename[PATH_MAX], usedname[PATH_MAX];
199 snprintf(filename, sizeof filename, "%s" SLASH "invitations" SLASH "%s", confbase, cookie);
200 snprintf(usedname, sizeof usedname, "%s" SLASH "invitations" SLASH "%s.used", confbase, cookie);
202 // Atomically rename the invitation file
203 if(rename(filename, usedname)) {
205 logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s tried to use non-existing invitation %s\n", c->hostname, cookie);
207 logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to rename invitation %s\n", cookie);
211 // Open the renamed file
212 FILE *f = fopen(usedname, "r");
214 logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to open invitation %s\n", cookie);
218 // Read the new node's Name from the file
220 fgets(buf, sizeof buf, f);
222 buf[strlen(buf) - 1] = 0;
224 len = strcspn(buf, " \t=");
225 char *name = buf + len;
226 name += strspn(name, " \t");
229 name += strspn(name, " \t");
233 if(!*buf || !*name || strcasecmp(buf, "Name") || !check_id(name)) {
234 logger(DEBUG_ALWAYS, LOG_ERR, "Invalid invitation file %s\n", cookie);
240 c->name = xstrdup(name);
242 // Send the node the contents of the invitation file
245 while((result = fread(buf, 1, sizeof buf, f)))
246 sptps_send_record(&c->sptps, 0, buf, result);
247 sptps_send_record(&c->sptps, 1, buf, 0);
251 c->status.invitation_used = true;
253 logger(DEBUG_CONNECTIONS, LOG_INFO, "Invitation %s succesfully sent to %s (%s)", cookie, c->name, c->hostname);
257 bool id_h(connection_t *c, const char *request) {
258 char name[MAX_STRING_SIZE];
260 if(sscanf(request, "%*d " MAX_STRING " %d.%d", name, &c->protocol_major, &c->protocol_minor) < 2) {
261 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ID", c->name,
266 /* Check if this is an invitation */
269 if(!invitation_key) {
270 logger(DEBUG_ALWAYS, LOG_ERR, "Got invitation from %s but we don't have an invitation key", c->hostname);
274 c->ecdsa = ecdsa_set_base64_public_key(name + 1);
276 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad invitation from %s", c->hostname);
280 c->status.invitation = true;
281 char *mykey = ecdsa_get_base64_public_key(invitation_key);
284 if(!send_request(c, "%d %s", ACK, mykey))
288 c->protocol_minor = 2;
290 return sptps_start(&c->sptps, c, false, false, invitation_key, c->ecdsa, "tinc invitation", 15, send_meta_sptps, receive_invitation_sptps);
293 /* Check if identity is a valid name */
295 if(!check_id(name)) {
296 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ID", c->name,
297 c->hostname, "invalid name");
301 /* If this is an outgoing connection, make sure we are connected to the right host */
304 if(strcmp(c->name, name)) {
305 logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s is %s instead of %s", c->hostname, name,
312 c->name = xstrdup(name);
315 /* Check if version matches */
317 if(c->protocol_major != myself->connection->protocol_major) {
318 logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s (%s) uses incompatible version %d.%d",
319 c->name, c->hostname, c->protocol_major, c->protocol_minor);
323 if(bypass_security) {
325 init_configuration(&c->config_tree);
326 c->allow_request = ACK;
330 if(!c->config_tree) {
331 init_configuration(&c->config_tree);
333 if(!read_host_config(c->config_tree, c->name)) {
334 logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s had unknown identity (%s)", c->hostname, c->name);
338 read_ecdsa_public_key(c);
340 if(c->protocol_minor && !ecdsa_active(c->ecdsa))
341 c->protocol_minor = 1;
344 /* Forbid version rollback for nodes whose ECDSA key we know */
346 if(ecdsa_active(c->ecdsa) && c->protocol_minor < 2) {
347 logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s (%s) tries to roll back protocol version to %d.%d",
348 c->name, c->hostname, c->protocol_major, c->protocol_minor);
352 c->allow_request = ACK;
353 char label[25 + strlen(myself->name) + strlen(c->name)];
356 snprintf(label, sizeof label, "tinc TCP key expansion %s %s", myself->name, c->name);
358 snprintf(label, sizeof label, "tinc TCP key expansion %s %s", c->name, myself->name);
360 return sptps_start(&c->sptps, c, c->outgoing, false, myself->connection->ecdsa, c->ecdsa, label, sizeof label, send_meta_sptps, receive_meta_sptps);
363 bool send_ack(connection_t *c) {
364 /* ACK message contains rest of the information the other end needs
365 to create node_t and edge_t structures. */
370 /* Estimate weight */
372 gettimeofday(&now, NULL);
373 c->estimated_weight = (now.tv_sec - c->start.tv_sec) * 1000 + (now.tv_usec - c->start.tv_usec) / 1000;
375 /* Check some options */
377 if((get_config_bool(lookup_config(c->config_tree, "IndirectData"), &choice) && choice) || myself->options & OPTION_INDIRECT)
378 c->options |= OPTION_INDIRECT;
380 if((get_config_bool(lookup_config(c->config_tree, "TCPOnly"), &choice) && choice) || myself->options & OPTION_TCPONLY)
381 c->options |= OPTION_TCPONLY | OPTION_INDIRECT;
383 if(myself->options & OPTION_PMTU_DISCOVERY)
384 c->options |= OPTION_PMTU_DISCOVERY;
386 choice = myself->options & OPTION_CLAMP_MSS;
387 get_config_bool(lookup_config(c->config_tree, "ClampMSS"), &choice);
389 c->options |= OPTION_CLAMP_MSS;
391 if(!get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight))
392 get_config_int(lookup_config(config_tree, "Weight"), &c->estimated_weight);
394 return send_request(c, "%d %s %d %x", ACK, myport, c->estimated_weight, (c->options & 0xffffff) | (PROT_MINOR << 24));
397 static void send_everything(connection_t *c) {
398 /* Send all known subnets and edges */
401 if(disablebuggypeers) {
404 char pad[MAXBUFSIZE - MAXSIZE];
407 memset(&zeropkt, 0, sizeof zeropkt);
408 zeropkt.pkt.len = MAXBUFSIZE;
409 send_tcppacket(c, &zeropkt.pkt);
412 for splay_each(node_t, n, node_tree) {
413 for splay_each(edge_t, e, n->edge_tree)
418 bool ack_h(connection_t *c, const char *request) {
419 char hisport[MAX_STRING_SIZE];
426 if(sscanf(request, "%*d " MAX_STRING " %d %x", hisport, &weight, &options) != 3) {
427 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ACK", c->name,
432 /* Check if we already have a node_t for him */
434 n = lookup_node(c->name);
438 n->name = xstrdup(c->name);
442 /* Oh dear, we already have a connection to this node. */
443 logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Established a second connection with %s (%s), closing old connection", n->connection->name, n->connection->hostname);
445 if(n->connection->outgoing) {
447 logger(DEBUG_ALWAYS, LOG_WARNING, "Two outgoing connections to the same node!");
449 c->outgoing = n->connection->outgoing;
451 n->connection->outgoing = NULL;
454 terminate_connection(n->connection, false);
455 /* Run graph algorithm to keep things in sync */
462 if(!(c->options & options & OPTION_PMTU_DISCOVERY)) {
463 c->options &= ~OPTION_PMTU_DISCOVERY;
464 options &= ~OPTION_PMTU_DISCOVERY;
466 c->options |= options;
468 if(get_config_int(lookup_config(c->config_tree, "PMTU"), &mtu) && mtu < n->mtu)
471 if(get_config_int(lookup_config(config_tree, "PMTU"), &mtu) && mtu < n->mtu)
474 if(get_config_bool(lookup_config(c->config_tree, "ClampMSS"), &choice)) {
476 c->options |= OPTION_CLAMP_MSS;
478 c->options &= ~OPTION_CLAMP_MSS;
481 /* Activate this connection */
483 c->allow_request = ALL;
484 c->status.active = true;
486 logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection with %s (%s) activated", c->name,
489 /* Send him everything we know */
493 /* Create an edge_t for this connection */
495 c->edge = new_edge();
496 c->edge->from = myself;
498 sockaddr2str(&c->address, &hisaddress, NULL);
499 c->edge->address = str2sockaddr(hisaddress, hisport);
501 c->edge->weight = (weight + c->estimated_weight) / 2;
502 c->edge->connection = c;
503 c->edge->options = c->options;
507 /* Notify everyone of the new edge */
509 send_add_edge(everyone, c->edge);
511 /* Run MST and SSSP algorithms */