/*
protocol_key.c -- handle the meta-protocol, key exchange
Copyright (C) 1999-2005 Ivo Timmermans,
- 2000-2011 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2013 Guus Sliepen <guus@tinc-vpn.org>
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
#include "system.h"
-#include "splay_tree.h"
#include "cipher.h"
#include "connection.h"
#include "crypto.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"
static bool mykeyused = false;
void send_key_changed(void) {
- splay_node_t *node;
- connection_t *c;
-
- send_request(broadcast, "%d %x %s", KEY_CHANGED, rand(), myself->name);
+ send_request(everyone, "%d %x %s", KEY_CHANGED, rand(), myself->name);
/* Immediately send new keys to directly connected nodes to keep UDP mappings alive */
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
- if(c->status.active && c->node && c->node->status.reachable)
+ for list_each(connection_t, c, connection_list)
+ if(c->status.active && c->node && c->node->status.reachable && !c->node->status.sptps)
send_ans_key(c->node);
+
+ /* Force key exchange for connections using SPTPS */
+
+ if(experimental) {
+ for splay_each(node_t, n, node_tree)
+ if(n->status.reachable && n->status.validkey && n->status.sptps)
+ sptps_force_kex(&n->sptps);
}
}
-bool key_changed_h(connection_t *c, char *request) {
+bool key_changed_h(connection_t *c, const char *request) {
char name[MAX_STRING_SIZE];
node_t *n;
if(sscanf(request, "%*d %*x " MAX_STRING, name) != 1) {
- logger(LOG_ERR, "Got bad %s from %s (%s)", "KEY_CHANGED",
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "KEY_CHANGED",
c->name, c->hostname);
return false;
}
n = lookup_node(name);
if(!n) {
- logger(LOG_ERR, "Got %s from %s (%s) origin %s which does not exist",
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist",
"KEY_CHANGED", c->name, c->hostname, name);
return true;
}
- n->status.validkey = false;
- n->last_req_key = 0;
+ if(!n->status.sptps) {
+ n->status.validkey = false;
+ n->last_req_key = 0;
+ }
/* Tell the others */
return true;
}
+static bool send_initial_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
+ node_t *to = handle;
+ to->sptps.send_data = send_sptps_data;
+ char buf[len * 4 / 3 + 5];
+ b64encode(data, buf, len);
+ return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_KEY, buf);
+}
+
bool send_req_key(node_t *to) {
+ if(to->status.sptps) {
+ if(!node_read_ecdsa_public_key(to)) {
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "No ECDSA key known for %s (%s)", to->name, to->hostname);
+ send_request(to->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, to->name, REQ_PUBKEY);
+ return true;
+ }
+
+ if(to->sptps.label)
+ logger(DEBUG_ALWAYS, LOG_DEBUG, "send_req_key(%s) called while sptps->label != NULL!", to->name);
+
+ char label[25 + strlen(myself->name) + strlen(to->name)];
+ snprintf(label, sizeof label, "tinc UDP key expansion %s %s", myself->name, to->name);
+ sptps_stop(&to->sptps);
+ to->status.validkey = false;
+ to->status.waitingforkey = true;
+ to->last_req_key = now.tv_sec;
+ to->incompression = myself->incompression;
+ return sptps_start(&to->sptps, to, true, true, myself->connection->ecdsa, to->ecdsa, label, sizeof label, send_initial_sptps_data, receive_sptps_record);
+ }
+
return send_request(to->nexthop->connection, "%d %s %s", REQ_KEY, myself->name, to->name);
}
-bool req_key_h(connection_t *c, char *request) {
+/* REQ_KEY is overloaded to allow arbitrary requests to be routed between two nodes. */
+
+static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, int reqno) {
+ switch(reqno) {
+ case REQ_PUBKEY: {
+ char *pubkey = ecdsa_get_base64_public_key(myself->connection->ecdsa);
+ send_request(from->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, from->name, ANS_PUBKEY, pubkey);
+ free(pubkey);
+ return true;
+ }
+
+ case ANS_PUBKEY: {
+ if(node_read_ecdsa_public_key(from)) {
+ logger(DEBUG_PROTOCOL, LOG_WARNING, "Got ANS_PUBKEY from %s (%s) even though we already have his pubkey", from->name, from->hostname);
+ 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(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ANS_PUBKEY", from->name, from->hostname, "invalid pubkey");
+ return true;
+ }
+
+ logger(DEBUG_PROTOCOL, LOG_INFO, "Learned ECDSA public key from %s (%s)", from->name, from->hostname);
+ append_config_file(from->name, "ECDSAPublicKey", pubkey);
+ return true;
+ }
+
+ case REQ_KEY: {
+ if(!node_read_ecdsa_public_key(from)) {
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "No ECDSA key known for %s (%s)", from->name, from->hostname);
+ send_request(from->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, from->name, REQ_PUBKEY);
+ return true;
+ }
+
+ if(from->sptps.label)
+ logger(DEBUG_ALWAYS, LOG_DEBUG, "Got REQ_KEY from %s while we already started a SPTPS session!", from->name);
+
+ 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(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_SPTPS_START", from->name, from->hostname, "invalid SPTPS data");
+ return true;
+ }
+
+ char label[25 + strlen(from->name) + strlen(myself->name)];
+ snprintf(label, sizeof label, "tinc UDP key expansion %s %s", from->name, myself->name);
+ sptps_stop(&from->sptps);
+ from->status.validkey = false;
+ from->status.waitingforkey = true;
+ from->last_req_key = now.tv_sec;
+ sptps_start(&from->sptps, from, false, true, myself->connection->ecdsa, from->ecdsa, label, sizeof label, send_sptps_data, receive_sptps_record);
+ sptps_receive_data(&from->sptps, buf, len);
+ return true;
+ }
+
+ case REQ_SPTPS: {
+ if(!from->status.validkey) {
+ logger(DEBUG_PROTOCOL, LOG_ERR, "Got REQ_SPTPS from %s (%s) but we don't have a valid key yet", from->name, from->hostname);
+ 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(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_SPTPS", from->name, from->hostname, "invalid SPTPS data");
+ return true;
+ }
+ sptps_receive_data(&from->sptps, buf, len);
+ return true;
+ }
+
+ default:
+ logger(DEBUG_ALWAYS, LOG_ERR, "Unknown extended REQ_KEY request from %s (%s): %s", from->name, from->hostname, request);
+ return true;
+ }
+}
+
+bool req_key_h(connection_t *c, const char *request) {
char from_name[MAX_STRING_SIZE];
char to_name[MAX_STRING_SIZE];
node_t *from, *to;
+ int reqno = 0;
- if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING, from_name, to_name) != 2) {
- logger(LOG_ERR, "Got bad %s from %s (%s)", "REQ_KEY", c->name,
+ if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING " %d", from_name, to_name, &reqno) < 2) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "REQ_KEY", c->name,
c->hostname);
return false;
}
if(!check_id(from_name) || !check_id(to_name)) {
- logger(LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_KEY", c->name, c->hostname, "invalid name");
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_KEY", c->name, c->hostname, "invalid name");
return false;
}
from = lookup_node(from_name);
if(!from) {
- logger(LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list",
+ logger(DEBUG_ALWAYS, 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 true;
}
to = lookup_node(to_name);
if(!to) {
- logger(LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list",
+ logger(DEBUG_ALWAYS, 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 true;
}
/* Check if this key request is for us */
- if(to == myself) { /* Yes, send our own key back */
+ if(to == myself) { /* Yes */
+ /* Is this an extended REQ_KEY message? */
+ if(experimental && reqno)
+ return req_key_ext_h(c, request, from, reqno);
+ /* No, just send our key back */
send_ans_key(from);
} else {
if(tunnelserver)
return true;
if(!to->status.reachable) {
- logger(LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
+ logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
"REQ_KEY", c->name, c->hostname, to_name);
return true;
}
}
bool send_ans_key(node_t *to) {
- size_t keylen = cipher_keylength(&myself->incipher);
+ if(to->status.sptps)
+ abort();
+
+ size_t keylen = cipher_keylength(myself->incipher);
char key[keylen * 2 + 1];
- cipher_open_by_nid(&to->incipher, cipher_get_nid(&myself->incipher));
- digest_open_by_nid(&to->indigest, digest_get_nid(&myself->indigest), digest_length(&myself->indigest));
+ cipher_close(to->incipher);
+ digest_close(to->indigest);
+
+ to->incipher = cipher_open_by_nid(cipher_get_nid(myself->incipher));
+ to->indigest = digest_open_by_nid(digest_get_nid(myself->indigest), digest_length(myself->indigest));
to->incompression = myself->incompression;
+ if(!to->incipher || !to->indigest)
+ abort();
+
randomize(key, keylen);
- cipher_set_key(&to->incipher, key, true);
- digest_set_key(&to->indigest, key, keylen);
+ if(!cipher_set_key(to->incipher, key, false))
+ abort();
+ if(!digest_set_key(to->indigest, key, keylen))
+ abort();
bin2hex(key, key, keylen);
- key[keylen * 2] = '\0';
// Reset sequence number and late packet window
mykeyused = true;
to->received_seqno = 0;
+ to->received = 0;
if(replaywin) memset(to->late, 0, replaywin);
- return send_request(to->nexthop->connection, "%d %s %s %s %d %d %zu %d", ANS_KEY,
+ return send_request(to->nexthop->connection, "%d %s %s %s %d %d %d %d", ANS_KEY,
myself->name, to->name, key,
- cipher_get_nid(&to->incipher),
- digest_get_nid(&to->indigest),
- digest_length(&to->indigest),
+ cipher_get_nid(to->incipher),
+ digest_get_nid(to->indigest),
+ (int)digest_length(to->indigest),
to->incompression);
}
-bool ans_key_h(connection_t *c, char *request) {
+bool ans_key_h(connection_t *c, const char *request) {
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] = "";
+ char address[MAX_STRING_SIZE] = "";
+ char port[MAX_STRING_SIZE] = "";
int cipher, digest, maclength, compression, keylen;
node_t *from, *to;
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(LOG_ERR, "Got bad %s from %s (%s)", "ANS_KEY", c->name,
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ANS_KEY", c->name,
c->hostname);
return false;
}
if(!check_id(from_name) || !check_id(to_name)) {
- logger(LOG_ERR, "Got bad %s from %s (%s): %s", "ANS_KEY", c->name, c->hostname, "invalid name");
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ANS_KEY", c->name, c->hostname, "invalid name");
return false;
}
from = lookup_node(from_name);
if(!from) {
- logger(LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list",
+ logger(DEBUG_ALWAYS, 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 true;
}
to = lookup_node(to_name);
if(!to) {
- logger(LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list",
+ logger(DEBUG_ALWAYS, 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 true;
}
return true;
if(!to->status.reachable) {
- logger(LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
+ logger(DEBUG_ALWAYS, LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
"ANS_KEY", c->name, c->hostname, to_name);
return true;
}
if(!*address && from->address.sa.sa_family != AF_UNSPEC) {
char *address, *port;
- ifdebug(PROTOCOL) logger(LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
sockaddr2str(&from->address, &address, &port);
send_request(to->nexthop->connection, "%s %s %s", request, address, port);
free(address);
return send_request(to->nexthop->connection, "%s", request);
}
- /* Check and lookup cipher and digest algorithms */
+ /* Don't use key material until every check has passed. */
+ cipher_close(from->outcipher);
+ digest_close(from->outdigest);
+ from->status.validkey = false;
- if(!cipher_open_by_nid(&from->outcipher, cipher)) {
- logger(LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname);
- return false;
+ if(compression < 0 || compression > 11) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname);
+ return true;
}
- keylen = strlen(key) / 2;
+ from->outcompression = compression;
- if(keylen != cipher_keylength(&from->outcipher)) {
- logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
- return false;
+ /* SPTPS or old-style key exchange? */
+
+ if(from->status.sptps) {
+ char buf[strlen(key)];
+ int len = b64decode(key, buf, strlen(key));
+
+ if(!len || !sptps_receive_data(&from->sptps, buf, len))
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error processing SPTPS data from %s (%s)", from->name, from->hostname);
+
+ if(from->status.validkey) {
+ if(*address && *port) {
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port);
+ sockaddr_t sa = str2sockaddr(address, port);
+ update_node_udp(from, &sa);
+ }
+
+ if(from->options & OPTION_PMTU_DISCOVERY && !(from->options & OPTION_TCPONLY))
+ send_mtu_probe(from);
+ }
+
+ return true;
}
- if(!digest_open_by_nid(&from->outdigest, digest, maclength)) {
- logger(LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname);
- return false;
+ /* Check and lookup cipher and digest algorithms */
+
+ if(cipher) {
+ if(!(from->outcipher = cipher_open_by_nid(cipher))) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname);
+ return false;
+ }
+ } else {
+ from->outcipher = NULL;
}
- if(maclength != digest_length(&from->outdigest)) {
- logger(LOG_ERR, "Node %s (%s) uses bogus MAC length!", from->name, from->hostname);
+ if(digest) {
+ if(!(from->outdigest = digest_open_by_nid(digest, maclength))) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname);
+ return false;
+ }
+ } else {
+ from->outdigest = NULL;
+ }
+
+ if(maclength != digest_length(from->outdigest)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses bogus MAC length!", from->name, from->hostname);
return false;
}
- if(compression < 0 || compression > 11) {
- logger(LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname);
+ /* Process key */
+
+ keylen = hex2bin(key, key, sizeof key);
+
+ if(keylen != cipher_keylength(from->outcipher)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
return true;
}
-
- from->outcompression = compression;
/* Update our copy of the origin's packet key */
- hex2bin(key, key, keylen);
- cipher_set_key(&from->outcipher, key, false);
- digest_set_key(&from->outdigest, key, keylen);
+ if(!cipher_set_key(from->outcipher, key, true))
+ return false;
+ if(!digest_set_key(from->outdigest, key, keylen))
+ return false;
from->status.validkey = true;
from->sent_seqno = 0;
if(*address && *port) {
- ifdebug(PROTOCOL) logger(LOG_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port);
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port);
sockaddr_t sa = str2sockaddr(address, port);
update_node_udp(from, &sa);
}
- if(from->options & OPTION_PMTU_DISCOVERY && !event_initialized(&from->mtuevent))
+ if(from->options & OPTION_PMTU_DISCOVERY && !(from->options & OPTION_TCPONLY))
send_mtu_probe(from);
return true;
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