along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: protocol.c,v 1.28.4.32 2000/09/15 12:58:40 zarq Exp $
+ $Id: protocol.c,v 1.28.4.33 2000/09/17 21:42:05 guus Exp $
*/
#include "config.h"
for (i = 0; i < strlen(id); i++)
{
if(!isalpha(id[i]) && id[i] != '_')
- {
- return 0;
- }
+ {
+ return 0;
+ }
}
return 1;
int send_request(conn_list_t *cl, const char *format, int request, /*args*/ ...)
{
va_list args;
- char *buffer = NULL;
+ char buffer[MAXBUFSIZE+1];
int len;
-
+
cp
- if(debug_lvl >= DEBUG_PROTOCOL)
- syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+ /* Use vsnprintf instead of vasprintf: faster, no memory fragmentation, cleanup is automatic,
+ and there is a limit on the input buffer anyway */
va_start(args, request);
- len = vasprintf(&buffer, format, args);
+ len = vsnprintf(buffer, MAXBUFSIZE+1, format, args);
va_end(args);
- if(len < 0 || !buffer)
+ if(len < 0 || len > MAXBUFSIZE)
{
- syslog(LOG_ERR, _("Error during vasprintf(): %m"));
+ syslog(LOG_ERR, _("Output buffer overflow while sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
return -1;
}
if(debug_lvl >= DEBUG_META)
- syslog(LOG_DEBUG, _("Sending meta data to %s (%s): %s"),
- cl->name, cl->hostname, buffer);
+ syslog(LOG_DEBUG, _("Sending %s to %s (%s): %s"), request_name[request],
+ cl->name, cl->hostname, buffer);
+ else if(debug_lvl >= DEBUG_PROTOCOL)
+ syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname);
+
if(cl->status.encryptin)
{
syslog(LOG_ERR, _("Sending meta data failed: %m"));
return -1;
}
-cp
+cp
}
/* Connection protocol:
Client Server
send_id(u)
send_challenge(R)
- send_chal_reply(BH)
- send_id(B)
- send_challenge(BR)
- send_chal_reply(BH)
- send_ack(B)
- send_ack(B)
+ send_chal_reply(H)
+ send_id(u)
+ send_challenge(R)
+ send_chal_reply(H)
+ ---------------------------------------
+ Any negotations about the meta protocol
+ encryption go here(u).
+ ---------------------------------------
+ send_ack(u)
+ send_ack(u)
+ ---------------------------------------
+ Other requests(E)...
(u) Unencrypted,
(R) RSA,
(H) SHA1,
- (B) Blowfish.
+ (E) Encrypted with symmetric cipher.
- Part of the challenge is directly used to set the blowfish key and the initial vector.
- (Twee vliegen in één klap!)
-*/
+ Part of the challenge is directly used to set the symmetric cipher key and the initial vector.
+ Since a man-in-the-middle cannot decrypt the RSA challenges, this means that he cannot get or
+ forge the key for the symmetric cipher.
+*/
int send_id(conn_list_t *cl)
{
cp
return send_request(cl, "%d %s %d %s", ID,
- myself->name, myself->protocol_version, opt2str(myself->options));
+ myself->name, myself->protocol_version, opt2str(myself->options));
}
int id_h(conn_list_t *cl)
syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname);
return -1;
}
-
+
/* Check if version matches */
-
+
if(cl->protocol_version != myself->protocol_version)
{
syslog(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"),
- cl->name, cl->hostname, cl->protocol_version);
+ cl->name, cl->hostname, cl->protocol_version);
return -1;
}
/* Check if option string is valid */
-
+
if((cl->options = str2opt(options)) == -1)
{
syslog(LOG_ERR, _("Peer %s uses invalid option string"), cl->hostname);
return -1;
}
-
+
/* Check if identity is a valid name */
-
+
if(!check_id(cl->name))
{
syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname);
return -1;
}
-
+
/* Load information about peer */
-
+
if(!read_id(cl))
{
syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->name);
cp
if(cl->chal_answer)
free(cl->chal_answer);
-
+
/* Allocate buffers for the challenge and the hash */
-
+
cl->chal_answer = xmalloc(SHA_DIGEST_LENGTH);
keylength = BN_num_bytes(cl->rsakey->length);
buffer = xmalloc(keylength*2);
/* Copy random data and the public key to the buffer */
-
+
RAND_bytes(buffer, keylength);
BN_bn2bin(cl->rsakey->length, buffer+keylength);
/* If we don't have a blowfish key set yet, use the random data from the challenge to do so. */
-
+
if(!cl->status.encryptin)
{
set_metakey(cl, buffer, keylength);
buffer[keylength*2] = '\0';
/* Send the challenge */
-
+
cl->allow_request = CHAL_REPLY;
x = send_request(cl, "%d %s", CHALLENGE, buffer);
free(buffer);
{
char *challenge;
int x;
-
+
cp
if(sscanf(cl->buffer, "%*d %as", &cl->name, &challenge) != 1)
{
}
/* Rest is done by send_chal_reply() */
-
+
x = send_chal_reply(cl, challenge);
free(challenge);
cp
int keylength;
char *hash;
int x;
-
+
cp
keylength = BN_num_bytes(myself->rsakey->length);
}
/* Allocate buffers for the challenge and the hash */
-
+
buffer = xmalloc(keylength*2);
hash = xmalloc(SHA_DIGEST_LENGTH*2+1);
/* Copy the incoming random data and our public key to the buffer */
- hex2bin(challenge, buffer, keylength);
+ hex2bin(challenge, buffer, keylength);
BN_bn2bin(myself->rsakey->length, buffer+keylength);
/* Calculate the hash from that */
-
+
SHA1(buffer, keylength*2, hash);
/* If we don't have a blowfish key set yet, use the random data from the challenge to do so. */
-
+
if(!cl->status.encrypted)
{
set_metakey(cl, buffer, keylength);
free(hash);
cp
return x;
-}
+}
int chal_reply_h(conn_list_t *cl)
{
}
/* Check if the length of the hash is all right */
-
+
if(strlen(hash) != SHA_DIGEST_LENGTH*2)
{
syslog(LOG_ERR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->name, cl->hostname);
return -1;
}
-
+
/* Convert the hash to binary format */
-
+
hex2bin(hash, hash, SHA_DIGEST_LENGTH);
-
+
/* Verify the incoming hash with the calculated hash */
-
+
if(!memcmp(hash, cl->chal_answer, SHA_DIGEST_LENGTH))
{
syslog(LOG_ERR, _("Intruder: wrong challenge reply from %s (%s)"), cl->name, cl->hostname);
If we are accepting this new connection, then send our identity,
if we are making this connecting, acknowledge.
*/
-
+
free(hash);
free(cl->chal_answer);
int ack_h(conn_list_t *cl)
{
conn_list_t *old;
-
+
cp
/* Okay, before we active the connection, we check if there is another entry
in the connection list with the same vpn_ip. If so, it presumably is an
old connection that has timed out but we don't know it yet.
*/
- while((old = lookup_id(cl->name)))
+ while((old = lookup_id(cl->name)))
{
if(debug_lvl > DEBUG_CONNECTIONS)
syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"),
int send_add_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
{
cp
-/* return send_request(cl, "%d %s %d %s", ADD_SUBNET,
- other->name, subnet->type, net2str(subnet)); */
return send_request(cl, "%d %s %s", ADD_SUBNET,
- other->name, net2str(subnet));
+ other->name, net2str(subnet));
}
int add_subnet_h(conn_list_t *cl)
{
+ char *subnetstr;
+ char *name;
+ conn_list_t *owner;
+ subnet_t *subnet, *old;
+cp
+ if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
+ {
+ syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname);
+ return -1;
+ }
+
+ /* Check if owner name is a valid */
+
+ if(!check_id(name))
+ {
+ syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
+ return -1;
+ }
+
+ /* Check if subnet string is valid */
+
+ if((subnet = str2net(subnetstr)) == -1)
+ {
+ syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
+ return -1;
+ }
+
+ /* Check if somebody tries to add a subnet of ourself */
+
+ if(!strcmp(name, myself->name))
+ {
+ syslog(LOG_ERR, _("Warning: got ADD_SUBNET from %s (%s) for ourself, restarting"),
+ cl->name, cl->hostname);
+ sighup = 1;
+ return 0;
+ }
+
+ /* Check if the owner of the new subnet is in the connection list */
+
+ if(!(owner = lookup_id(name))
+ {
+ syslog(LOG_NOTICE, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"),
+ name, cl->name, cl->hostname);
+ }
+
+
}
int send_del_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
int del_subnet_h(conn_list_t *cl)
{
+ char *subnetstr;
+ char *name;
+ conn_list_t *owner;
+ subnet_t *subnet, *old;
+cp
+ if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
+ {
+ syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s)"), cl->name, cl->hostname);
+ return -1;
+ }
+
+ /* Check if owner name is a valid */
+
+ if(!check_id(name))
+ {
+ syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname);
+ return -1;
+ }
+
+ /* Check if subnet string is valid */
+
+ if((subnet = str2net(subnetstr)) == -1)
+ {
+ syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
+ return -1;
+ }
+
+ /* Check if somebody tries to delete a subnet of ourself */
+
+ if(!strcmp(name, myself->name))
+ {
+ syslog(LOG_ERR, _("Warning: got DEL_SUBNET from %s (%s) for ourself, restarting"),
+ cl->name, cl->hostname);
+ sighup = 1;
+ return 0;
+ }
+
+ /* Check if the owner of the new subnet is in the connection list */
+
+ if(!(owner = lookup_id(name))
+ {
+ syslog(LOG_NOTICE, _("Got DEL_SUBNET for %s from %s (%s) which is not in our connection list"),
+ name, cl->name, cl->hostname);
+ }
}
/* New and closed connections notification */
{
syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname);
return -1;
- }
+ }
/* Check if option string is valid */
-
+
if((new->options = str2opt(options)) == -1)
{
syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid option string"), cl->name, cl->hostname);
}
/* Check if identity is a valid name */
-
+
if(!check_id(new->name))
{
syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
return -1;
}
-
+
/* Check if somebody tries to add ourself */
-
+
if(!strcmp(new->name, myself->name))
{
syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname);
/* Fill in more of the new conn_list structure */
new->hostname = hostlookup(htonl(new->real_ip));
-
+
/* Check if the new host already exists in the connnection list */
if((old = lookup_id(new->name)))
{
if(debug_lvl > DEBUG_CONNECTIONS)
syslog(LOG_NOTICE, _("Got duplicate ADD_HOST for %s (%s) from %s (%s)"),
- old->name, old->hostname, new->name, new->hostname);
- return 0;
+ old->name, old->hostname, new->name, new->hostname);
+ return 0;
}
else
{
if(debug_lvl > DEBUG_CONNECTIONS)
syslog(LOG_NOTICE, _("Removing old entry for %s (%s)"),
- old->name, old->hostname);
+ old->name, old->hostname);
old->status.active = 0;
terminate_connection(old);
}
new->nexthop = cl;
new->status.active = 1;
-
+
/* Hook it up into the conn_list */
conn_list_add(conn_list, new);
/* Tell the rest about the new host */
-
+
notify_others(new, cl, send_add_host);
-
+
cp
return 0;
}
{
cp
return send_request(cl, "%d %s %lx:%d", DEL_HOST,
- other->name, other->real_ip, other->port);
+ other->name, other->real_ip, other->port);
}
int del_host_h(conn_list_t *cl)
ip_t address;
port_t port;
conn_list_t *old;
-
+
cp
if(sscanf(cl->buffer, "%*d %as %lx:%d", &id, &address, &port) != 3)
{
syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"),
- cl->name, cl->hostname);
+ cl->name, cl->hostname);
return -1;
- }
+ }
/* Check if somebody tries to delete ourself */
-
+
if(!strcmp(id, myself->name))
{
syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"),
- cl->name, cl->hostname);
+ cl->name, cl->hostname);
sighup = 1;
return 0;
}
if(debug_lvl > DEBUG_CONNECTIONS)
{
syslog(LOG_NOTICE, _("Got DEL_HOST for %s from %s (%s) which is not in our connection list"),
- id, cl->name, cl->hostname);
+ id, cl->name, cl->hostname);
}
cp
return 0;
if(sscanf(cl->buffer, "%*d %d %as", &statusno, &statusstring) != 2)
{
syslog(LOG_ERR, _("Got bad STATUS from %s (%s)"),
- cl->name, cl->hostname);
+ cl->name, cl->hostname);
return -1;
}
if(debug_lvl > DEBUG_STATUS)
{
syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"),
- cl->name, cl->hostname, status_text[statusno], statusstring);
+ cl->name, cl->hostname, status_text[statusno], statusstring);
}
cp
if(sscanf(cl->buffer, "%*d %d %as", &errno, &errorstring) != 2)
{
syslog(LOG_ERR, _("Got bad error from %s (%s)"),
- cl->name, cl->hostname);
+ cl->name, cl->hostname);
return -1;
}
if(debug_lvl > DEBUG_error)
{
syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"),
- cl->name, cl->hostname, strerror(errno), errorstring);
+ cl->name, cl->hostname, strerror(errno), errorstring);
}
free(errorstring);
{
if(p!=cl && p->status.meta && p->status.active)
send_request(p, "%d %s", KEY_CHANGED,
- from->name);
+ from->name);
}
cp
return 0;
if(sscanf(cl->buffer, "%*d %as", &from_id) != 1)
{
syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"),
- cl->name, cl->hostname);
+ cl->name, cl->hostname);
return -1;
- }
+ }
if(!(from = lookup_id(from_id)))
{
syslog(LOG_ERR, _("Got KEY_CHANGED from %s (%s) origin %s which does not exist in our connection list"),
- cl->name, cl->hostname, from_id);
+ cl->name, cl->hostname, from_id);
free(from_id);
return -1;
}
free(from_id);
-
+
from->status.validkey = 0;
from->status.waitingforkey = 0;
-
+
send_key_changed(from, cl);
cp
return 0;
}
-
+
int send_req_key(conn_list_t *from, conn_list_t *to)
{
cp
return send_request(to->nexthop, "%d %s %s", REQ_KEY,
- from->name, to->name);
+ from->name, to->name);
}
int req_key_h(conn_list_t *cl)
if(sscanf(cl->buffer, "%*d %as %as", &from_id, &to_id) != 2)
{
syslog(LOG_ERR, _("Got bad REQ_KEY from %s (%s)"),
- cl->name, cl->hostname);
+ cl->name, cl->hostname);
return -1;
- }
+ }
if(!(from = lookup_id(from_id)))
{
syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) origin %s which does not exist in our connection list"),
- cl->name, cl->hostname, from_id);
+ cl->name, cl->hostname, from_id);
free(from_id); free(to_id);
return -1;
}
if(!(to = lookup_id(to_id)))
{
syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) destination %s which does not exist in our connection list"),
- cl->name, cl->hostname, to_id);
+ cl->name, cl->hostname, to_id);
free(from_id); free(to_id);
return -1;
}
{
cp
return send_request(to->nexthop, "%d %s %s %s", ANS_KEY,
- from->name, to->name, datakey);
+ from->name, to->name, datakey);
}
int ans_key_h(conn_list_t *cl)
if(sscanf(cl->buffer, "%*d %as %as %as", &from_id, &to_id, &datakey) != 3)
{
syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s)"),
- cl->name, cl->hostname);
+ cl->name, cl->hostname);
return -1;
- }
+ }
if(!(from = lookup_id(from_id)))
{
syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) origin %s which does not exist in our connection list"),
- cl->name, cl->hostname, from_id);
+ cl->name, cl->hostname, from_id);
free(from_id); free(to_id); free(datakey);
return -1;
}
if(!strcmp(to_id, myself->name))
{
/* It is for us, convert it to binary and set the key with it. */
-
+
keylength = strlen(datakey);
-
+
if((keylength%2) || (keylength <= 0))
{
syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key"),
- cl->name, cl->hostname, from->name);
+ cl->name, cl->hostname, from->name);
free(from_id); free(to_id); free(datakey);
return -1;
}
if(!(to = lookup_id(to_id)))
{
syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) destination %s which does not exist in our connection list"),
- cl->name, cl->hostname, to_id);
+ cl->name, cl->hostname, to_id);
free(from_id); free(to_id); free(datakey);
return -1;
}
*/
int notify_others(conn_list_t *new, conn_list_t *source,
- int (*function)(conn_list_t*, conn_list_t*))
+ int (*function)(conn_list_t*, conn_list_t*))
{
conn_list_t *p;
cp
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