/*
protocol_key.c -- handle the meta-protocol, key exchange
- Copyright (C) 1999-2003 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2003 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- $Id: protocol_key.c,v 1.4 2003/08/24 20:38:27 guus Exp $
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "system.h"
-#include "avl_tree.h"
#include "connection.h"
#include "logger.h"
+#include "meshlink_internal.h"
#include "net.h"
#include "netutl.h"
#include "node.h"
+#include "prf.h"
#include "protocol.h"
+#include "sptps.h"
#include "utils.h"
#include "xalloc.h"
-bool mykeyused = false;
-
-bool send_key_changed(connection_t *c, const node_t *n)
-{
- cp();
+static const int req_key_timeout = 2;
- /* Only send this message if some other daemon requested our key previously.
- This reduces unnecessary key_changed broadcasts.
- */
-
- if(n == myself && !mykeyused)
- return true;
+bool key_changed_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
+ assert(request);
+ assert(*request);
- return send_request(c, "%d %lx %s", KEY_CHANGED, random(), n->name);
-}
-
-bool key_changed_h(connection_t *c)
-{
char name[MAX_STRING_SIZE];
node_t *n;
- cp();
-
- if(sscanf(c->buffer, "%*d %*x " MAX_STRING, name) != 1) {
- logger(LOG_ERR, _("Got bad %s from %s (%s)"), "KEY_CHANGED",
- c->name, c->hostname);
+ if(sscanf(request, "%*d %*x " MAX_STRING, name) != 1) {
+ logger(mesh, MESHLINK_ERROR, "Got bad %s from %s", "KEY_CHANGED", c->name);
return false;
}
- if(seen_request(c->buffer))
+ if(seen_request(mesh, request)) {
return true;
+ }
- n = lookup_node(name);
+ n = lookup_node(mesh, name);
if(!n) {
- logger(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist"),
- "KEY_CHANGED", c->name, c->hostname, name);
- return false;
+ logger(mesh, MESHLINK_ERROR, "Got %s from %s origin %s which does not exist", "KEY_CHANGED", c->name, name);
+ return true;
}
- n->status.validkey = false;
- n->status.waitingforkey = false;
-
/* Tell the others */
- forward_request(c);
+ forward_request(mesh, c, NULL, request);
return true;
}
-bool send_req_key(connection_t *c, const node_t *from, const node_t *to)
-{
- cp();
+static bool send_initial_sptps_data(void *handle, uint8_t type, const void *data, size_t len) {
+ (void)type;
+
+ assert(data);
+ assert(len);
+
+ node_t *to = handle;
+ meshlink_handle_t *mesh = to->mesh;
+ to->sptps.send_data = send_sptps_data;
+ char buf[len * 4 / 3 + 5];
+ b64encode(data, buf, len);
+ return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_KEY, buf);
+}
+
+bool send_req_key(meshlink_handle_t *mesh, node_t *to) {
+ if(!node_read_public_key(mesh, to)) {
+ logger(mesh, MESHLINK_DEBUG, "No ECDSA key known for %s", to->name);
+ send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d", REQ_KEY, mesh->self->name, to->name, REQ_PUBKEY);
+ return true;
+ }
+
+ if(to->sptps.label) {
+ logger(mesh, MESHLINK_DEBUG, "send_req_key(%s) called while sptps->label != NULL!", to->name);
+ }
+
+ char label[sizeof(meshlink_udp_label) + strlen(mesh->self->name) + strlen(to->name) + 2];
+ snprintf(label, sizeof(label), "%s %s %s", meshlink_udp_label, mesh->self->name, to->name);
+ sptps_stop(&to->sptps);
+ to->status.validkey = false;
+ to->status.waitingforkey = true;
+ to->last_req_key = mesh->loop.now.tv_sec;
+ return sptps_start(&to->sptps, to, true, true, mesh->private_key, to->ecdsa, label, sizeof(label) - 1, send_initial_sptps_data, receive_sptps_record);
+}
+
+/* REQ_KEY is overloaded to allow arbitrary requests to be routed between two nodes. */
+
+static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *request, node_t *from, int reqno) {
+ (void)c;
+
+ switch(reqno) {
+ case REQ_PUBKEY: {
+ char *pubkey = ecdsa_get_base64_public_key(mesh->private_key);
+
+ if(!from->nexthop || !from->nexthop->connection) {
+ return false;
+ }
+
+ send_request(mesh, from->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, from->name, ANS_PUBKEY, pubkey);
+ free(pubkey);
+ return true;
+ }
+
+ case ANS_PUBKEY: {
+ if(node_read_public_key(mesh, from)) {
+ logger(mesh, MESHLINK_WARNING, "Got ANS_PUBKEY from %s even though we already have his pubkey", from->name);
+ return true;
+ }
+
+ char pubkey[MAX_STRING_SIZE];
+
+ if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, pubkey) != 1 || !(from->ecdsa = ecdsa_set_base64_public_key(pubkey))) {
+ logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "ANS_PUBKEY", from->name, "invalid pubkey");
+ return true;
+ }
+
+ logger(mesh, MESHLINK_INFO, "Learned ECDSA public key from %s", from->name);
+ from->status.dirty = true;
+
+ /* If we are trying to form an outgoing connection to this node, retry immediately */
+ for list_each(outgoing_t, outgoing, mesh->outgoings) {
+ if(outgoing->node == from && outgoing->ev.cb) {
+ outgoing->timeout = 0;
+ timeout_set(&mesh->loop, &outgoing->ev, &(struct timespec) {
+ 0, 0
+ });
+ }
+ }
+
+ /* Also reset any UTCP timers */
+ utcp_reset_timers(from->utcp);
+
+ return true;
+ }
+
+ case REQ_KEY: {
+ if(!node_read_public_key(mesh, from)) {
+ logger(mesh, MESHLINK_DEBUG, "No ECDSA key known for %s", from->name);
+ send_request(mesh, from->nexthop->connection, NULL, "%d %s %s %d", REQ_KEY, mesh->self->name, from->name, REQ_PUBKEY);
+ return true;
+ }
+
+ if(from->sptps.label) {
+ logger(mesh, MESHLINK_DEBUG, "Got REQ_KEY from %s while we already started a SPTPS session!", from->name);
+
+ if(mesh->loop.now.tv_sec < from->last_req_key + req_key_timeout && strcmp(mesh->self->name, from->name) < 0) {
+ logger(mesh, MESHLINK_DEBUG, "Ignoring REQ_KEY from %s.", from->name);
+ return true;
+ }
+ }
+
+ char buf[MAX_STRING_SIZE];
+ int len;
+
+ if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) {
+ logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_SPTPS_START", from->name, "invalid SPTPS data");
+ return true;
+ }
+
+ char label[sizeof(meshlink_udp_label) + strlen(from->name) + strlen(mesh->self->name) + 2];
+ snprintf(label, sizeof(label), "%s %s %s", meshlink_udp_label, from->name, mesh->self->name);
+ sptps_stop(&from->sptps);
+ from->status.validkey = false;
+ from->status.waitingforkey = true;
+ from->last_req_key = mesh->loop.now.tv_sec;
+
+ if(!sptps_start(&from->sptps, from, false, true, mesh->private_key, from->ecdsa, label, sizeof(label) - 1, send_sptps_data, receive_sptps_record)) {
+ logger(mesh, MESHLINK_ERROR, "Could not start SPTPS session with %s: %s", from->name, strerror(errno));
+ return true;
+ }
+
+ if(!sptps_receive_data(&from->sptps, buf, len)) {
+ logger(mesh, MESHLINK_ERROR, "Could not process SPTPS data from %s: %s", from->name, strerror(errno));
+ return true;
+ }
+
+ return true;
+ }
+
+ case REQ_SPTPS: {
+ if(!from->status.validkey) {
+ logger(mesh, MESHLINK_ERROR, "Got REQ_SPTPS from %s but we don't have a valid key yet", from->name);
+ return true;
+ }
+
+ char buf[MAX_STRING_SIZE];
+ int len;
+
+ if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) {
+ logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_SPTPS", from->name, "invalid SPTPS data");
+ return true;
+ }
+
+ if(!sptps_receive_data(&from->sptps, buf, len)) {
+ logger(mesh, MESHLINK_ERROR, "Could not process SPTPS data from %s: %s", from->name, strerror(errno));
+ return true;
+ }
+
+ return true;
+ }
- return send_request(c, "%d %s %s", REQ_KEY, from->name, to->name);
+ default:
+ logger(mesh, MESHLINK_ERROR, "Unknown extended REQ_KEY request from %s: %s", from->name, request);
+ return true;
+ }
}
-bool req_key_h(connection_t *c)
-{
+bool req_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
+ assert(request);
+ assert(*request);
+
char from_name[MAX_STRING_SIZE];
char to_name[MAX_STRING_SIZE];
node_t *from, *to;
+ int reqno = 0;
- cp();
+ if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING " %d", from_name, to_name, &reqno) < 2) {
+ logger(mesh, MESHLINK_ERROR, "Got bad %s from %s", "REQ_KEY", c->name);
+ return false;
+ }
- if(sscanf(c->buffer, "%*d " MAX_STRING " " MAX_STRING, from_name, to_name) != 2) {
- logger(LOG_ERR, _("Got bad %s from %s (%s)"), "REQ_KEY", c->name,
- c->hostname);
+ if(!check_id(from_name) || !check_id(to_name)) {
+ logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_KEY", c->name, "invalid name");
return false;
}
- from = lookup_node(from_name);
+ from = lookup_node(mesh, from_name);
if(!from) {
- logger(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist in our connection list"),
- "REQ_KEY", c->name, c->hostname, from_name);
- return false;
+ logger(mesh, MESHLINK_ERROR, "Got %s from %s origin %s which does not exist in our connection list",
+ "REQ_KEY", c->name, from_name);
+ return true;
}
- to = lookup_node(to_name);
+ to = lookup_node(mesh, to_name);
if(!to) {
- logger(LOG_ERR, _("Got %s from %s (%s) destination %s which does not exist in our connection list"),
- "REQ_KEY", c->name, c->hostname, to_name);
- return false;
+ logger(mesh, MESHLINK_ERROR, "Got %s from %s destination %s which does not exist in our connection list",
+ "REQ_KEY", c->name, to_name);
+ return true;
}
/* Check if this key request is for us */
- if(to == myself) { /* Yes, send our own key back */
- mykeyused = true;
- from->received_seqno = 0;
- memset(from->late, 0, sizeof(from->late));
- send_ans_key(c, myself, from);
+ if(to == mesh->self) { /* Yes */
+ /* Is this an extended REQ_KEY message? */
+ if(reqno) {
+ return req_key_ext_h(mesh, c, request, from, reqno);
+ }
+
+ /* This should never happen. Ignore it, unless it came directly from the connected peer, in which case we disconnect. */
+ return from->connection != c;
} else {
- send_req_key(to->nexthop->connection, from, to);
+ if(!to->status.reachable) {
+ logger(mesh, MESHLINK_WARNING, "Got %s from %s destination %s which is not reachable",
+ "REQ_KEY", c->name, to_name);
+ return true;
+ }
+
+ send_request(mesh, to->nexthop->connection, NULL, "%s", request);
}
return true;
}
-bool send_ans_key(connection_t *c, const node_t *from, const node_t *to)
-{
- char key[MAX_STRING_SIZE];
-
- cp();
-
- bin2hex(from->key, key, from->keylength);
- key[from->keylength * 2] = '\0';
-
- return send_request(c, "%d %s %s %s %d %d %d %d", ANS_KEY,
- from->name, to->name, key,
- from->cipher ? from->cipher->nid : 0,
- from->digest ? from->digest->type : 0, from->maclength,
- from->compression);
-}
+bool ans_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
+ assert(request);
+ assert(*request);
-bool ans_key_h(connection_t *c)
-{
char from_name[MAX_STRING_SIZE];
char to_name[MAX_STRING_SIZE];
char key[MAX_STRING_SIZE];
+ char address[MAX_STRING_SIZE] = "";
+ char port[MAX_STRING_SIZE] = "";
int cipher, digest, maclength, compression;
node_t *from, *to;
- cp();
+ if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d "MAX_STRING" "MAX_STRING,
+ from_name, to_name, key, &cipher, &digest, &maclength,
+ &compression, address, port) < 7) {
+ logger(mesh, MESHLINK_ERROR, "Got bad %s from %s", "ANS_KEY", c->name);
+ return false;
+ }
- if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d",
- from_name, to_name, key, &cipher, &digest, &maclength,
- &compression) != 7) {
- logger(LOG_ERR, _("Got bad %s from %s (%s)"), "ANS_KEY", c->name,
- c->hostname);
+ if(!check_id(from_name) || !check_id(to_name)) {
+ logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "ANS_KEY", c->name, "invalid name");
return false;
}
- from = lookup_node(from_name);
+ from = lookup_node(mesh, from_name);
if(!from) {
- logger(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist in our connection list"),
- "ANS_KEY", c->name, c->hostname, from_name);
- return false;
+ logger(mesh, MESHLINK_ERROR, "Got %s from %s origin %s which does not exist in our connection list",
+ "ANS_KEY", c->name, from_name);
+ return true;
}
- to = lookup_node(to_name);
+ to = lookup_node(mesh, to_name);
if(!to) {
- logger(LOG_ERR, _("Got %s from %s (%s) destination %s which does not exist in our connection list"),
- "ANS_KEY", c->name, c->hostname, to_name);
- return false;
+ logger(mesh, MESHLINK_ERROR, "Got %s from %s destination %s which does not exist in our connection list",
+ "ANS_KEY", c->name, to_name);
+ return true;
}
/* Forward it if necessary */
- if(to != myself) {
- return send_request(to->nexthop->connection, "%s", c->buffer);
- }
+ if(to != mesh->self) {
+ if(!to->status.reachable) {
+ logger(mesh, MESHLINK_WARNING, "Got %s from %s destination %s which is not reachable",
+ "ANS_KEY", c->name, to_name);
+ return true;
+ }
- /* Update our copy of the origin's packet key */
+ if(from == to) {
+ logger(mesh, MESHLINK_WARNING, "Got %s from %s from %s to %s",
+ "ANS_KEY", c->name, from_name, to_name);
+ return true;
+ }
- if(from->key)
- free(from->key);
+ /* Append the known UDP address of the from node, if we have a confirmed one */
+ if(!*address && from->status.udp_confirmed && from->address.sa.sa_family != AF_UNSPEC) {
+ char *address, *port;
+ logger(mesh, MESHLINK_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
+ sockaddr2str(&from->address, &address, &port);
+ send_request(mesh, to->nexthop->connection, NULL, "%s %s %s", request, address, port);
+ free(address);
+ free(port);
+ return true;
+ }
- from->key = xstrdup(key);
- from->keylength = strlen(key) / 2;
- hex2bin(from->key, from->key, from->keylength);
- from->key[from->keylength] = '\0';
+ return send_request(mesh, to->nexthop->connection, NULL, "%s", request);
+ }
- from->status.validkey = true;
- from->status.waitingforkey = false;
- from->sent_seqno = 0;
+ /* Is this an ANS_KEY informing us of our own reflexive UDP address? */
- /* Check and lookup cipher and digest algorithms */
+ if(from == mesh->self) {
+ if(*key == '.' && *address && *port) {
+ logger(mesh, MESHLINK_DEBUG, "Learned our own reflexive UDP address from %s: %s port %s", c->name, address, port);
- if(cipher) {
- from->cipher = EVP_get_cipherbynid(cipher);
+ /* Inform all other nodes we want to communicate with and which are reachable via this connection */
+ for splay_each(node_t, n, mesh->nodes) {
+ if(n->nexthop != c->node) {
+ continue;
+ }
- if(!from->cipher) {
- logger(LOG_ERR, _("Node %s (%s) uses unknown cipher!"), from->name,
- from->hostname);
- return false;
- }
+ if(n->status.udp_confirmed) {
+ continue;
+ }
- if(from->keylength != from->cipher->key_len + from->cipher->iv_len) {
- logger(LOG_ERR, _("Node %s (%s) uses wrong keylength!"), from->name,
- from->hostname);
- return false;
+ if(!n->status.waitingforkey && !n->status.validkey) {
+ continue;
+ }
+
+ logger(mesh, MESHLINK_DEBUG, "Forwarding our own reflexive UDP address to %s", n->name);
+ send_request(mesh, c, NULL, "%d %s %s . -1 -1 -1 0 %s %s", ANS_KEY, mesh->self->name, n->name, address, port);
+ }
+ } else {
+ logger(mesh, MESHLINK_WARNING, "Got %s from %s from %s to %s",
+ "ANS_KEY", c->name, from_name, to_name);
}
- } else {
- from->cipher = NULL;
+
+ return true;
}
- from->maclength = maclength;
+ /* Process SPTPS data if present */
- if(digest) {
- from->digest = EVP_get_digestbynid(digest);
+ if(*key != '.') {
+ /* Don't use key material until every check has passed. */
+ from->status.validkey = false;
- if(!from->digest) {
- logger(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name,
- from->hostname);
- return false;
+ /* Compression is not supported. */
+ if(compression != 0) {
+ logger(mesh, MESHLINK_ERROR, "Node %s uses bogus compression level!", from->name);
+ return true;
}
- if(from->maclength > from->digest->md_size || from->maclength < 0) {
- logger(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"),
- from->name, from->hostname);
- return false;
- }
- } else {
- from->digest = NULL;
- }
+ char buf[strlen(key)];
+ int len = b64decode(key, buf, strlen(key));
- if(compression < 0 || compression > 11) {
- logger(LOG_ERR, _("Node %s (%s) uses bogus compression level!"), from->name, from->hostname);
- return false;
+ if(!len || !sptps_receive_data(&from->sptps, buf, len)) {
+ logger(mesh, MESHLINK_ERROR, "Error processing SPTPS data from %s", from->name);
+ }
}
-
- from->compression = compression;
- if(from->cipher)
- EVP_EncryptInit_ex(&from->packet_ctx, from->cipher, NULL, from->key, from->key + from->cipher->key_len);
+ if(from->status.validkey) {
+ if(*address && *port) {
+ logger(mesh, MESHLINK_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port);
+ sockaddr_t sa = str2sockaddr(address, port);
+ update_node_udp(mesh, from, &sa);
+ }
- flush_queue(from);
+ send_mtu_probe(mesh, from);
+ }
return true;
}
projects / meshlink / blobdiff