/*
net_packet.c -- Handles in- and outgoing VPN packets
- Copyright (C) 1998-2003 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2003 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 1998-2005 Ivo Timmermans,
+ 2000-2006 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
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: net_packet.c,v 1.1.2.49 2003/12/27 16:32:52 guus Exp $
+ $Id$
*/
#include "system.h"
int keylifetime = 0;
int keyexpires = 0;
-bool strictsource = true;
EVP_CIPHER_CTX packet_ctx;
static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
route(n, packet);
}
-static bool authenticate_udppacket(node_t *n, vpn_packet_t *inpkt) {
- char hmac[EVP_MAX_MD_SIZE];
-
- if(inpkt->len < sizeof(inpkt->seqno) + (myself->digest ? myself->maclength : 0))
- return false;
-
- /* Check the message authentication code */
-
- if(myself->digest && myself->maclength) {
- HMAC(myself->digest, myself->key, myself->keylength,
- (char *) &inpkt->seqno, inpkt->len - myself->maclength, hmac, NULL);
-
- if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len - myself->maclength, myself->maclength))
- return false;
- }
-
- return true;
-}
-
static void receive_udppacket(node_t *n, vpn_packet_t *inpkt)
{
vpn_packet_t pkt1, pkt2;
int nextpkt = 0;
vpn_packet_t *outpkt = pkt[0];
int outlen, outpad;
+ unsigned char hmac[EVP_MAX_MD_SIZE];
int i;
cp();
- if(!authenticate_udppacket(n, inpkt)) {
- ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"),
- n->name, n->hostname);
+ /* Check packet length */
+
+ if(inpkt->len < sizeof(inpkt->seqno) + myself->maclength) {
+ ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got too short packet from %s (%s)"),
+ n->name, n->hostname);
return;
}
- inpkt->len -= myself->digest ? myself->maclength : 0;
+ /* Check the message authentication code */
+
+ if(myself->digest && myself->maclength) {
+ inpkt->len -= myself->maclength;
+ HMAC(myself->digest, myself->key, myself->keylength,
+ (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL);
+
+ if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, myself->maclength)) {
+ ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"),
+ n->name, n->hostname);
+ return;
+ }
+ }
/* Decrypt the packet */
outpkt = pkt[nextpkt++];
if(!EVP_DecryptInit_ex(&packet_ctx, NULL, NULL, NULL, NULL)
- || !EVP_DecryptUpdate(&packet_ctx, (char *) &outpkt->seqno, &outlen,
- (char *) &inpkt->seqno, inpkt->len)
- || !EVP_DecryptFinal_ex(&packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
+ || !EVP_DecryptUpdate(&packet_ctx, (unsigned char *) &outpkt->seqno, &outlen,
+ (unsigned char *) &inpkt->seqno, inpkt->len)
+ || !EVP_DecryptFinal_ex(&packet_ctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Error decrypting packet from %s (%s): %s"),
n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
return;
memset(n->late, 0, sizeof(n->late));
} else if (inpkt->seqno <= n->received_seqno) {
- if(inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8 || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) {
+ if((n->received_seqno >= sizeof(n->late) * 8 && inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8) || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) {
logger(LOG_WARNING, _("Got late or replayed packet from %s (%s), seqno %d, last received %d"),
n->name, n->hostname, inpkt->seqno, n->received_seqno);
- } else
- for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
- n->late[(inpkt->seqno / 8) % sizeof(n->late)] |= 1 << i % 8;
+ return;
+ }
+ } else {
+ for(i = n->received_seqno + 1; i < inpkt->seqno; i++)
+ n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8;
}
}
- n->received_seqno = inpkt->seqno;
- n->late[(n->received_seqno / 8) % sizeof(n->late)] &= ~(1 << n->received_seqno % 8);
+ n->late[(inpkt->seqno / 8) % sizeof(n->late)] &= ~(1 << inpkt->seqno % 8);
+
+ if(inpkt->seqno > n->received_seqno)
+ n->received_seqno = inpkt->seqno;
if(n->received_seqno > MAX_SEQNO)
keyexpires = 0;
receive_packet(c->node, &outpkt);
}
-static void send_udppacket(node_t *n, vpn_packet_t *inpkt)
+static void send_udppacket(node_t *n, vpn_packet_t *origpkt)
{
vpn_packet_t pkt1, pkt2;
vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
+ vpn_packet_t *inpkt = origpkt;
int nextpkt = 0;
vpn_packet_t *outpkt;
int origlen;
outpkt = pkt[nextpkt++];
if(!EVP_EncryptInit_ex(&n->packet_ctx, NULL, NULL, NULL, NULL)
- || !EVP_EncryptUpdate(&n->packet_ctx, (char *) &outpkt->seqno, &outlen,
- (char *) &inpkt->seqno, inpkt->len)
- || !EVP_EncryptFinal_ex(&n->packet_ctx, (char *) &outpkt->seqno + outlen, &outpad)) {
+ || !EVP_EncryptUpdate(&n->packet_ctx, (unsigned char *) &outpkt->seqno, &outlen,
+ (unsigned char *) &inpkt->seqno, inpkt->len)
+ || !EVP_EncryptFinal_ex(&n->packet_ctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while encrypting packet to %s (%s): %s"),
n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
goto end;
/* Add the message authentication code */
if(n->digest && n->maclength) {
- HMAC(n->digest, n->key, n->keylength, (char *) &inpkt->seqno,
- inpkt->len, (char *) &inpkt->seqno + inpkt->len, &outlen);
+ HMAC(n->digest, n->key, n->keylength, (unsigned char *) &inpkt->seqno,
+ inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL);
inpkt->len += n->maclength;
}
}
end:
- inpkt->len = origlen;
+ origpkt->len = origlen;
}
/*
ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"),
packet->len, from->name, from->hostname);
+ if(from != myself)
+ send_packet(myself, packet);
+
for(node = connection_tree->head; node; node = node->next) {
c = node->data;
sockaddr_t from;
socklen_t fromlen = sizeof(from);
node_t *n;
- static time_t lasttime = 0;
cp();
n = lookup_node_udp(&from);
- if(!n && !strictsource && myself->digest && myself->maclength && lasttime != now) {
- avl_node_t *node;
-
- lasttime = now;
-
- for(node = node_tree->head; node; node = node->next) {
- n = node->data;
-
- if(authenticate_udppacket(n, &pkt)) {
- update_node_address(n, &from);
- logger(LOG_DEBUG, _("Updated address of node %s to %s"), n->name, n->hostname);
- break;
- }
- }
- }
-
if(!n) {
hostname = sockaddr2hostname(&from);
- logger(LOG_WARNING, _("Received UDP packet from unknown source %s"), hostname);
+ logger(LOG_WARNING, _("Received UDP packet from unknown source %s"),
+ hostname);
free(hostname);
return;
}
projects / tinc / blobdiff