X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol_key.c;h=7e122068edd672c7a8117107675dab425bd6b59b;hp=aae5516c04b519f82b17e71a14970aa51c520a75;hb=ff306f0cdaedb50de1472e7c1fb55de922a6ca60;hpb=108b238915c5f58b3d94ab433dc5d04e064c2b11

diff --git a/src/protocol_key.c b/src/protocol_key.c
index aae5516c..7e122068 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -1,7 +1,7 @@
 /*
     protocol_key.c -- handle the meta-protocol, key exchange
     Copyright (C) 1999-2005 Ivo Timmermans,
-                  2000-2009 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2012 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
@@ -20,7 +20,6 @@
 
 #include "system.h"
 
-#include "splay_tree.h"
 #include "cipher.h"
 #include "connection.h"
 #include "crypto.h"
@@ -28,29 +27,45 @@
 #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;
 
-bool send_key_changed() {
-	/* Only send this message if some other daemon requested our key previously.
-	   This reduces unnecessary key_changed broadcasts.
-	 */
+void send_key_changed(void) {
+	send_request(everyone, "%d %x %s", KEY_CHANGED, rand(), myself->name);
 
-	if(!mykeyused)
-		return true;
+	/* Immediately send new keys to directly connected nodes to keep UDP mappings alive */
+
+	for(list_node_t *node = connection_list->head, *next; node; node = next) {
+		next = node->next;
+		connection_t *c = node->data;
+		if(c->status.active && c->node && c->node->status.reachable) {
+			if(!c->node->status.sptps)
+				send_ans_key(c->node);
+		}
+	}
+
+	/* Force key exchange for connections using SPTPS */
 
-	return send_request(broadcast, "%d %x %s", KEY_CHANGED, rand(), myself->name);
+	if(experimental) {
+		for(splay_node_t *node = node_tree->head; node; node = node->next) {
+			node_t *n = node->data;
+			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;
 	}
@@ -61,13 +76,15 @@ bool key_changed_h(connection_t *c, char *request) {
 	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 false;
+		return true;
 	}
 
-	n->status.validkey = false;
-	n->status.waitingforkey = false;
+	if(!n->status.sptps) {
+		n->status.validkey = false;
+		n->last_req_key = 0;
+	}
 
 	/* Tell the others */
 
@@ -77,48 +94,160 @@ bool key_changed_h(connection_t *c, char *request) {
 	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;
+		}
+                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 = time(NULL);
+		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 || !ecdsa_set_base64_public_key(&from->ecdsa, 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;
+			}
+		}
+
+		case REQ_SPTPS: {
+			char buf[MAX_STRING_SIZE];
+			if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1) {
+				logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_KEY", from->name, from->hostname, "invalid SPTPS data");
+				return true;
+			}
+			int len = b64decode(buf, buf, strlen(buf));
+
+
+			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 = time(NULL);
+			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_PACKET: {
+			if(!from->status.validkey) {
+				logger(DEBUG_PROTOCOL, LOG_ERR, "Got REQ_PACKET from %s (%s) but we don't have a valid key yet", from->name, from->hostname);
+				return true;
+			}
+
+			char buf[MAX_STRING_SIZE];
+			if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1) {
+				logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_KEY", from->name, from->hostname, "invalid SPTPS data");
+				return true;
+			}
+			int len = b64decode(buf, buf, strlen(buf));
+			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(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 false;
+		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 false;
+		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 false;
+			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;
 		}
@@ -130,6 +259,9 @@ bool req_key_h(connection_t *c, char *request) {
 }
 
 bool send_ans_key(node_t *to) {
+	if(to->status.sptps)
+		abort();
+
 	size_t keylen = cipher_keylength(&myself->incipher);
 	char key[keylen * 2 + 1];
 
@@ -138,109 +270,161 @@ bool send_ans_key(node_t *to) {
 	to->incompression = myself->incompression;
 
 	randomize(key, keylen);
-	cipher_set_key(&to->incipher, key, true);
+	cipher_set_key(&to->incipher, key, false);
+	digest_set_key(&to->indigest, key, keylen);
 
 	bin2hex(key, key, keylen);
-	key[keylen * 2] = '\0';
 
 	// Reset sequence number and late packet window
 	mykeyused = true;
 	to->received_seqno = 0;
-	memset(to->late, 0, sizeof(to->late));
+	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),
+						(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];
-	int cipher, digest, maclength, compression;
+        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",
+	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) != 7) {
-		logger(LOG_ERR, "Got bad %s from %s (%s)", "ANS_KEY", c->name,
+		&compression, address, port) < 7) {
+		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(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 false;
+		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 false;
+		return true;
 	}
 
 	/* Forward it if necessary */
 
 	if(to != myself) {
 		if(tunnelserver)
-			return false;
+			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;
+			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);
+			free(port);
+			return true;
+		}
+
 		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. */
+	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;
+	}
+
+	from->outcompression = compression;
+
+	/* SPTPS or old-style key exchange? */
+
+	if(from->status.sptps) {
+		char buf[strlen(key)];
+		int len = b64decode(key, buf, strlen(key));
+
+		if(!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)
+				send_mtu_probe(from);
+		}
+
+		return true;
 	}
 
-	if(strlen(key) / 2 != cipher_keylength(&from->outcipher)) {
-		logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
+	/* Check and lookup cipher and digest algorithms */
+
+	if(!cipher_open_by_nid(&from->outcipher, cipher)) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname);
 		return false;
 	}
 
 	if(!digest_open_by_nid(&from->outdigest, digest, maclength)) {
-		logger(LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname);
+		logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname);
 		return false;
 	}
 
 	if(maclength != digest_length(&from->outdigest)) {
-		logger(LOG_ERR, "Node %s (%s) uses bogus MAC length!", from->name, from->hostname);
+		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);
-		return false;
+	/* 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, cipher_keylength(&from->outcipher));
-	cipher_set_key(&from->outcipher, key, false);
+	cipher_set_key(&from->outcipher, key, true);
+	digest_set_key(&from->outdigest, key, keylen);
 
 	from->status.validkey = true;
-	from->status.waitingforkey = false;
 	from->sent_seqno = 0;
 
-	if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuprobes)
+	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)
 		send_mtu_probe(from);
 
 	return true;