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"
28 #include "meshlink_internal.h"
38 #include "ed25519/sha512.h"
40 extern bool node_write_dclass(meshlink_handle_t *mesh, node_t *n);
42 static bool send_proxyrequest(meshlink_handle_t *mesh, connection_t *c) {
43 switch(mesh->proxytype) {
48 sockaddr2str(&c->address, &host, &port);
49 send_request(mesh, c, "CONNECT %s:%s HTTP/1.1\r\n\r", host, port);
55 if(c->address.sa.sa_family != AF_INET) {
56 logger(mesh, MESHLINK_ERROR, "Cannot connect to an IPv6 host through a SOCKS 4 proxy!");
59 char s4req[9 + (mesh->proxyuser ? strlen(mesh->proxyuser) : 0)];
62 memcpy(s4req + 2, &c->address.in.sin_port, 2);
63 memcpy(s4req + 4, &c->address.in.sin_addr, 4);
65 memcpy(s4req + 8, mesh->proxyuser, strlen(mesh->proxyuser));
66 s4req[sizeof s4req - 1] = 0;
68 return send_meta(mesh, c, s4req, sizeof s4req);
71 int len = 3 + 6 + (c->address.sa.sa_family == AF_INET ? 4 : 16);
74 len += 3 + strlen(mesh->proxyuser) + strlen(mesh->proxypass);
82 s5req[i++] = strlen(mesh->proxyuser);
83 memcpy(s5req + i, mesh->proxyuser, strlen(mesh->proxyuser));
84 i += strlen(mesh->proxyuser);
85 s5req[i++] = strlen(mesh->proxypass);
86 memcpy(s5req + i, mesh->proxypass, strlen(mesh->proxypass));
87 i += strlen(mesh->proxypass);
95 if(c->address.sa.sa_family == AF_INET) {
97 memcpy(s5req + i, &c->address.in.sin_addr, 4);
99 memcpy(s5req + i, &c->address.in.sin_port, 2);
102 } else if(c->address.sa.sa_family == AF_INET6) {
104 memcpy(s5req + i, &c->address.in6.sin6_addr, 16);
106 memcpy(s5req + i, &c->address.in6.sin6_port, 2);
110 logger(mesh, MESHLINK_ERROR, "Address family %hx not supported for SOCKS 5 proxies!", c->address.sa.sa_family);
115 return send_meta(mesh, c, s5req, sizeof s5req);
118 logger(mesh, MESHLINK_ERROR, "Proxy type not implemented yet");
123 logger(mesh, MESHLINK_ERROR, "Unknown proxy type");
128 bool send_id(meshlink_handle_t *mesh, connection_t *c) {
130 int minor = mesh->self->connection->protocol_minor;
132 if(mesh->proxytype && c->outgoing)
133 if(!send_proxyrequest(mesh, c))
136 return send_request(mesh, c, "%d %s %d.%d", ID, mesh->self->connection->name, mesh->self->connection->protocol_major, minor);
139 static bool finalize_invitation(meshlink_handle_t *mesh, connection_t *c, const void *data, uint16_t len) {
140 if(strchr(data, '\n')) {
141 logger(mesh, MESHLINK_ERROR, "Received invalid key from invited node %s (%s)!\n", c->name, c->hostname);
145 // Create a new host config file
146 char filename[PATH_MAX];
147 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, c->name);
148 if(!access(filename, F_OK)) {
149 logger(mesh, MESHLINK_ERROR, "Host config file for %s (%s) already exists!\n", c->name, c->hostname);
153 FILE *f = fopen(filename, "w");
155 logger(mesh, MESHLINK_ERROR, "Error trying to create %s: %s\n", filename, strerror(errno));
159 fprintf(f, "ECDSAPublicKey = %s\n", (const char *)data);
162 logger(mesh, MESHLINK_INFO, "Key succesfully received from %s (%s)", c->name, c->hostname);
164 //TODO: callback to application to inform of an accepted invitation
166 sptps_send_record(&c->sptps, 2, data, 0);
168 load_all_nodes(mesh);
173 static bool receive_invitation_sptps(void *handle, uint8_t type, const void *data, uint16_t len) {
174 connection_t *c = handle;
175 meshlink_handle_t *mesh = c->mesh;
180 if(type == 1 && c->status.invitation_used)
181 return finalize_invitation(mesh, c, data, len);
183 if(type != 0 || len != 18 || c->status.invitation_used)
186 // Recover the filename from the cookie and the key
187 char *fingerprint = ecdsa_get_base64_public_key(mesh->invitation_key);
189 char hashbuf[18 + strlen(fingerprint)];
191 memcpy(hashbuf, data, 18);
192 memcpy(hashbuf + 18, fingerprint, sizeof hashbuf - 18);
193 sha512(hashbuf, sizeof hashbuf, hash);
194 b64encode_urlsafe(hash, cookie, 18);
197 char filename[PATH_MAX], usedname[PATH_MAX];
198 snprintf(filename, sizeof filename, "%s" SLASH "invitations" SLASH "%s", mesh->confbase, cookie);
199 snprintf(usedname, sizeof usedname, "%s" SLASH "invitations" SLASH "%s.used", mesh->confbase, cookie);
201 // Atomically rename the invitation file
202 if(rename(filename, usedname)) {
204 logger(mesh, MESHLINK_ERROR, "Peer %s tried to use non-existing invitation %s\n", c->hostname, cookie);
206 logger(mesh, MESHLINK_ERROR, "Error trying to rename invitation %s\n", cookie);
210 // Open the renamed file
211 FILE *f = fopen(usedname, "r");
213 logger(mesh, MESHLINK_ERROR, "Error trying to open invitation %s\n", cookie);
217 // Read the new node's Name from the file
219 fgets(buf, sizeof buf, f);
221 buf[strlen(buf) - 1] = 0;
223 len = strcspn(buf, " \t=");
224 char *name = buf + len;
225 name += strspn(name, " \t");
228 name += strspn(name, " \t");
232 if(!*buf || !*name || strcasecmp(buf, "Name") || !check_id(name)) {
233 logger(mesh, MESHLINK_ERROR, "Invalid invitation file %s\n", cookie);
239 c->name = xstrdup(name);
241 // Send the node the contents of the invitation file
244 while((result = fread(buf, 1, sizeof buf, f)))
245 sptps_send_record(&c->sptps, 0, buf, result);
246 sptps_send_record(&c->sptps, 1, buf, 0);
250 c->status.invitation_used = true;
252 logger(mesh, MESHLINK_INFO, "Invitation %s succesfully sent to %s (%s)", cookie, c->name, c->hostname);
256 bool id_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
257 char name[MAX_STRING_SIZE];
259 if(sscanf(request, "%*d " MAX_STRING " %d.%d", name, &c->protocol_major, &c->protocol_minor) < 2) {
260 logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s)", "ID", c->name,
265 /* Check if this is an invitation */
268 if(!mesh->invitation_key) {
269 logger(mesh, MESHLINK_ERROR, "Got invitation from %s but we don't have an invitation key", c->hostname);
273 c->ecdsa = ecdsa_set_base64_public_key(name + 1);
275 logger(mesh, MESHLINK_ERROR, "Got bad invitation from %s", c->hostname);
279 c->status.invitation = true;
280 char *mykey = ecdsa_get_base64_public_key(mesh->invitation_key);
283 if(!send_request(mesh, c, "%d %s", ACK, mykey))
287 c->protocol_minor = 2;
288 c->allow_request = 1;
290 return sptps_start(&c->sptps, c, false, false, mesh->invitation_key, c->ecdsa, "meshlink invitation", 15, send_meta_sptps, receive_invitation_sptps);
293 /* Check if identity is a valid name */
295 if(!check_id(name)) {
296 logger(mesh, MESHLINK_ERROR, "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(mesh, MESHLINK_ERROR, "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 != mesh->self->connection->protocol_major) {
318 logger(mesh, MESHLINK_ERROR, "Peer %s (%s) uses incompatible version %d.%d",
319 c->name, c->hostname, c->protocol_major, c->protocol_minor);
323 if(!c->config_tree) {
324 init_configuration(&c->config_tree);
326 if(!read_host_config(mesh, c->config_tree, c->name)) {
327 logger(mesh, MESHLINK_ERROR, "Peer %s had unknown identity (%s)", c->hostname, c->name);
331 read_ecdsa_public_key(mesh, c);
333 if(c->protocol_minor && !ecdsa_active(c->ecdsa))
334 c->protocol_minor = 1;
337 /* Forbid version rollback for nodes whose ECDSA key we know */
339 if(ecdsa_active(c->ecdsa) && c->protocol_minor < 2) {
340 logger(mesh, MESHLINK_ERROR, "Peer %s (%s) tries to roll back protocol version to %d.%d",
341 c->name, c->hostname, c->protocol_major, c->protocol_minor);
345 c->allow_request = ACK;
346 char label[25 + strlen(mesh->self->name) + strlen(c->name)];
349 snprintf(label, sizeof label, "meshlink TCP key expansion %s %s", mesh->self->name, c->name);
351 snprintf(label, sizeof label, "meshlink TCP key expansion %s %s", c->name, mesh->self->name);
353 return sptps_start(&c->sptps, c, c->outgoing, false, mesh->self->connection->ecdsa, c->ecdsa, label, sizeof label, send_meta_sptps, receive_meta_sptps);
356 bool send_ack(meshlink_handle_t *mesh, connection_t *c) {
358 /* Check some options */
360 if(mesh->self->options & OPTION_PMTU_DISCOVERY)
361 c->options |= OPTION_PMTU_DISCOVERY;
363 return send_request(mesh, c, "%d %s %d %x", ACK, mesh->myport, mesh->dclass, (c->options & 0xffffff) | (PROT_MINOR << 24));
366 static void send_everything(meshlink_handle_t *mesh, connection_t *c) {
367 /* Send all known subnets and edges */
369 for splay_each(node_t, n, mesh->nodes) {
370 for splay_each(edge_t, e, n->edge_tree)
371 send_add_edge(mesh, c, e);
375 bool ack_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
376 char hisport[MAX_STRING_SIZE];
382 if(sscanf(request, "%*d " MAX_STRING " %d %x", hisport, &dclass, &options) != 3) {
383 logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s)", "ACK", c->name,
388 /* Check if we already have a node_t for him */
390 n = lookup_node(mesh, c->name);
394 n->name = xstrdup(c->name);
398 /* Oh dear, we already have a connection to this node. */
399 logger(mesh, MESHLINK_DEBUG, "Established a second connection with %s (%s), closing old connection", n->connection->name, n->connection->hostname);
401 if(n->connection->outgoing) {
403 logger(mesh, MESHLINK_WARNING, "Two outgoing connections to the same node!");
405 c->outgoing = n->connection->outgoing;
407 n->connection->outgoing = NULL;
410 terminate_connection(mesh, n->connection, false);
411 /* Run graph algorithm to keep things in sync */
417 node_write_dclass(mesh, n);
421 if(!(c->options & options & OPTION_PMTU_DISCOVERY)) {
422 c->options &= ~OPTION_PMTU_DISCOVERY;
423 options &= ~OPTION_PMTU_DISCOVERY;
425 c->options |= options;
427 /* Activate this connection */
429 c->allow_request = ALL;
430 c->status.active = true;
432 logger(mesh, MESHLINK_INFO, "Connection with %s (%s) activated", c->name,
435 /* Send him everything we know */
437 send_everything(mesh, c);
439 /* Create an edge_t for this connection */
441 c->edge = new_edge();
442 c->edge->from = mesh->self;
444 sockaddr2str(&c->address, &hisaddress, NULL);
445 c->edge->address = str2sockaddr(hisaddress, hisport);
447 c->edge->weight = cweight_from_dclass(dclass);
448 c->edge->connection = c;
449 c->edge->options = c->options;
451 edge_add(mesh, c->edge);
453 /* Notify everyone of the new edge */
455 send_add_edge(mesh, mesh->everyone, c->edge);
457 /* Run MST and SSSP algorithms */