X-Git-Url: https://git.librecmc.org/?p=oweals%2Ftinc.git;a=blobdiff_plain;f=src%2Fprotocol_key.c;h=6140a5321ece9be3815d03a9a689c4f14c36084d;hp=8517411824cd08c1cb7f4580acf67e226464acf0;hb=e97943b7cc9c851ae36f5a41e2b6102faa74193f;hpb=a227843b739d279b63adcf3736ebb03d856080c4

diff --git a/src/protocol_key.c b/src/protocol_key.c
index 8517411..6140a53 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>
+                  2000-2016 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
@@ -34,17 +34,23 @@
 #include "utils.h"
 #include "xalloc.h"
 
-bool mykeyused = false;
+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) {
+	avl_node_t *node;
+	connection_t *c;
 
-	if(!mykeyused)
-		return true;
+	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;
 
-	return send_request(broadcast, "%d %x %s", KEY_CHANGED, rand(), myself->name);
+		if(c->status.active && c->node && c->node->status.reachable) {
+			send_ans_key(c->node);
+		}
+	}
 }
 
 bool key_changed_h(connection_t *c) {
@@ -52,29 +58,36 @@ bool key_changed_h(connection_t *c) {
 	node_t *n;
 
 	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);
+		logger(LOG_ERR, "Got bad %s from %s (%s)", "KEY_CHANGED",
+		       c->name, c->hostname);
 		return false;
 	}
 
-	if(seen_request(c->buffer))
+	if(!check_id(name)) {
+		logger(LOG_ERR, "Got bad %s from %s (%s): %s", "KEY_CHANGED", c->name, c->hostname, "invalid name");
+		return false;
+	}
+
+	if(seen_request(c->buffer)) {
 		return true;
+	}
 
 	n = lookup_node(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(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->status.waitingforkey = false;
+	n->last_req_key = 0;
 
 	/* Tell the others */
 
-	if(!tunnelserver)
+	if(!tunnelserver) {
 		forward_request(c);
+	}
 
 	return true;
 }
@@ -89,38 +102,46 @@ bool req_key_h(connection_t *c) {
 	node_t *from, *to;
 
 	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);
+		logger(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");
 		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"),
-			   "REQ_KEY", c->name, c->hostname, from_name);
-		return false;
+		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 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"),
-			   "REQ_KEY", c->name, c->hostname, to_name);
-		return false;
+		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 true;
 	}
 
 	/* Check if this key request is for us */
 
-	if(to == myself) {			/* Yes, send our own key back */
-		send_ans_key(from);
-	} else {
-		if(tunnelserver)
+	if(to == myself) {                      /* Yes, send our own key back */
+		if(!send_ans_key(from)) {
 			return false;
+		}
+	} else {
+		if(tunnelserver) {
+			return true;
+		}
 
 		if(!to->status.reachable) {
-			logger(LOG_WARNING, _("Got %s from %s (%s) destination %s which is not reachable"),
-				"REQ_KEY", c->name, c->hostname, to_name);
+			logger(LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
+			       "REQ_KEY", c->name, c->hostname, to_name);
 			return true;
 		}
 
@@ -131,8 +152,6 @@ bool req_key_h(connection_t *c) {
 }
 
 bool send_ans_key(node_t *to) {
-	char *key;
-
 	// Set key parameters
 	to->incipher = myself->incipher;
 	to->inkeylength = myself->inkeylength;
@@ -144,98 +163,134 @@ bool send_ans_key(node_t *to) {
 	to->inkey = xrealloc(to->inkey, to->inkeylength);
 
 	// Create a new key
-	RAND_pseudo_bytes((unsigned char *)to->inkey, to->inkeylength);
-	if(to->incipher)
-		EVP_DecryptInit_ex(&to->inctx, to->incipher, NULL, (unsigned char *)to->inkey, (unsigned char *)to->inkey + to->incipher->key_len);
+	if(1 != RAND_bytes((unsigned char *)to->inkey, to->inkeylength)) {
+		int err = ERR_get_error();
+		logger(LOG_ERR, "Failed to generate random for key (%s)", ERR_error_string(err, NULL));
+		return false; // Do not send insecure keys, let connection attempt fail.
+	}
+
+	if(to->incipher) {
+		EVP_DecryptInit_ex(to->inctx, to->incipher, NULL, (unsigned char *)to->inkey, (unsigned char *)to->inkey + EVP_CIPHER_key_length(to->incipher));
+	}
 
 	// 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);
+	}
 
 	// Convert to hexadecimal and send
-	key = alloca(2 * to->inkeylength + 1);
+	char key[2 * to->inkeylength + 1];
 	bin2hex(to->inkey, key, to->inkeylength);
 	key[to->inkeylength * 2] = '\0';
 
 	return send_request(to->nexthop->connection, "%d %s %s %s %d %d %d %d", ANS_KEY,
-			myself->name, to->name, key,
-			to->incipher ? to->incipher->nid : 0,
-			to->indigest ? to->indigest->type : 0, to->inmaclength,
-			to->incompression);
+	                    myself->name, to->name, key,
+	                    to->incipher ? EVP_CIPHER_nid(to->incipher) : 0,
+	                    to->indigest ? EVP_MD_type(to->indigest) : 0, to->inmaclength,
+	                    to->incompression);
 }
 
 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;
 
-	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(sscanf(c->buffer, "%*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,
+		       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");
 		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"),
-			   "ANS_KEY", c->name, c->hostname, from_name);
-		return false;
+		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 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"),
-			   "ANS_KEY", c->name, c->hostname, to_name);
-		return false;
+		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 true;
 	}
 
 	/* Forward it if necessary */
 
 	if(to != myself) {
-		if(tunnelserver)
-			return false;
+		if(tunnelserver) {
+			return true;
+		}
 
 		if(!to->status.reachable) {
-			logger(LOG_WARNING, _("Got %s from %s (%s) destination %s which is not reachable"),
-				"ANS_KEY", c->name, c->hostname, to_name);
+			logger(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 && to->minmtu) {
+			char *address, *port;
+			ifdebug(PROTOCOL) logger(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", c->buffer, address, port);
+			free(address);
+			free(port);
 			return true;
 		}
 
 		return send_request(to->nexthop->connection, "%s", c->buffer);
 	}
 
+	/* Don't use key material until every check has passed. */
+	from->status.validkey = false;
+
 	/* Update our copy of the origin's packet key */
 	from->outkey = xrealloc(from->outkey, strlen(key) / 2);
-
-	from->outkey = xstrdup(key);
 	from->outkeylength = strlen(key) / 2;
-	hex2bin(key, from->outkey, from->outkeylength);
 
-	from->status.waitingforkey = false;
+	if(!hex2bin(key, from->outkey, from->outkeylength)) {
+		logger(LOG_ERR, "Got bad %s from %s(%s): %s", "ANS_KEY", from->name, from->hostname, "invalid key");
+		return true;
+	}
+
 	/* Check and lookup cipher and digest algorithms */
 
 	if(cipher) {
 		from->outcipher = EVP_get_cipherbynid(cipher);
 
 		if(!from->outcipher) {
-			logger(LOG_ERR, _("Node %s (%s) uses unknown cipher!"), from->name,
-				   from->hostname);
-			return false;
+			logger(LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name,
+			       from->hostname);
+			return true;
 		}
 
-		if(from->outkeylength != from->outcipher->key_len + from->outcipher->iv_len) {
-			logger(LOG_ERR, _("Node %s (%s) uses wrong keylength!"), from->name,
-				   from->hostname);
-			return false;
+		if(from->outkeylength != EVP_CIPHER_key_length(from->outcipher) + EVP_CIPHER_iv_length(from->outcipher)) {
+			logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name,
+			       from->hostname);
+			return true;
 		}
 	} else {
+		if(from->outkeylength != 1) {
+			logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
+			return true;
+		}
+
 		from->outcipher = NULL;
 	}
 
@@ -245,39 +300,46 @@ bool ans_key_h(connection_t *c) {
 		from->outdigest = EVP_get_digestbynid(digest);
 
 		if(!from->outdigest) {
-			logger(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name,
-				   from->hostname);
-			return false;
+			logger(LOG_ERR, "Node %s (%s) uses unknown digest!", from->name,
+			       from->hostname);
+			return true;
 		}
 
-		if(from->outmaclength > from->outdigest->md_size || from->outmaclength < 0) {
-			logger(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"),
-				   from->name, from->hostname);
-			return false;
+		if(from->outmaclength > EVP_MD_size(from->outdigest) || from->outmaclength < 0) {
+			logger(LOG_ERR, "Node %s (%s) uses bogus MAC length!",
+			       from->name, from->hostname);
+			return true;
 		}
 	} else {
 		from->outdigest = NULL;
 	}
 
 	if(compression < 0 || compression > 11) {
-		logger(LOG_ERR, _("Node %s (%s) uses bogus compression level!"), from->name, from->hostname);
-		return false;
+		logger(LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname);
+		return true;
 	}
-	
+
 	from->outcompression = compression;
 
 	if(from->outcipher)
-		if(!EVP_EncryptInit_ex(&from->outctx, from->outcipher, NULL, (unsigned char *)from->outkey, (unsigned char *)from->outkey + from->outcipher->key_len)) {
-			logger(LOG_ERR, _("Error during initialisation of key from %s (%s): %s"),
-					from->name, from->hostname, ERR_error_string(ERR_get_error(), NULL));
-			return false;
+		if(!EVP_EncryptInit_ex(from->outctx, from->outcipher, NULL, (unsigned char *)from->outkey, (unsigned char *)from->outkey + EVP_CIPHER_key_length(from->outcipher))) {
+			logger(LOG_ERR, "Error during initialisation of key from %s (%s): %s",
+			       from->name, from->hostname, ERR_error_string(ERR_get_error(), NULL));
+			return true;
 		}
 
 	from->status.validkey = true;
 	from->sent_seqno = 0;
 
-	if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuprobes)
+	if(*address && *port) {
+		ifdebug(PROTOCOL) logger(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->mtuevent) {
 		send_mtu_probe(from);
+	}
 
 	return true;
 }