/*
protocol_key.c -- handle the meta-protocol, key exchange
Copyright (C) 1999-2005 Ivo Timmermans,
- 2000-2010 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
#include "utils.h"
#include "xalloc.h"
-bool mykeyused = false;
+static bool mykeyused = false;
-void send_key_changed() {
+void send_key_changed(void) {
avl_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)
+
+ if(c->status.active && c->node && c->node->status.reachable) {
send_ans_key(c->node);
+ }
}
}
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);
+ c->name, c->hostname);
return false;
}
return false;
}
- if(seen_request(c->buffer))
+ 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);
+ "KEY_CHANGED", c->name, c->hostname, name);
return true;
}
/* Tell the others */
- if(!tunnelserver)
+ if(!tunnelserver) {
forward_request(c);
+ }
return true;
}
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);
+ c->hostname);
return false;
}
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);
+ "REQ_KEY", c->name, c->hostname, from_name);
return true;
}
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);
+ "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);
+ if(to == myself) { /* Yes, send our own key back */
+ if(!send_ans_key(from)) {
+ return false;
+ }
} else {
- if(tunnelserver)
+ 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);
+ "REQ_KEY", c->name, c->hostname, to_name);
return true;
}
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;
- if(replaywin) memset(to->late, 0, replaywin);
+
+ if(replaywin) {
+ memset(to->late, 0, replaywin);
+ }
// Convert to hexadecimal and send
char key[2 * to->inkeylength + 1];
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) {
node_t *from, *to;
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) {
+ 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);
+ c->hostname);
return false;
}
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);
+ "ANS_KEY", c->name, c->hostname, from_name);
return true;
}
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);
+ "ANS_KEY", c->name, c->hostname, to_name);
return true;
}
/* Forward it if necessary */
if(to != myself) {
- if(tunnelserver)
+ 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);
+ "ANS_KEY", c->name, c->hostname, to_name);
return true;
}
- if(!*address && from->address.sa.sa_family != AF_UNSPEC) {
+ 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);
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);
+
+ 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(!from->outcipher) {
logger(LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name,
- from->hostname);
+ from->hostname);
return true;
}
- if(from->outkeylength != from->outcipher->key_len + from->outcipher->iv_len) {
+ 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);
+ 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;
}
if(!from->outdigest) {
logger(LOG_ERR, "Node %s (%s) uses unknown digest!", from->name,
- from->hostname);
+ from->hostname);
return true;
}
- if(from->outmaclength > from->outdigest->md_size || from->outmaclength < 0) {
+ 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);
+ from->name, from->hostname);
return true;
}
} else {
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)) {
+ 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));
+ from->name, from->hostname, ERR_error_string(ERR_get_error(), NULL));
return true;
}
update_node_udp(from, &sa);
}
- if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuevent)
+ if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuevent) {
send_mtu_probe(from);
+ }
return true;
}
projects / tinc / blobdiff