along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: protocol.c,v 1.28.4.45 2000/10/24 15:46:17 guus Exp $
+ $Id: protocol.c,v 1.28.4.55 2000/11/04 16:39:19 guus Exp $
*/
#include "config.h"
#include <netinet/in.h>
#include <openssl/sha.h>
+#include <openssl/rand.h>
+#include <openssl/evp.h>
#include "conf.h"
-#include "encr.h"
#include "net.h"
#include "netutl.h"
#include "protocol.h"
#include "meta.h"
+#include "connlist.h"
#include "system.h"
syslog(LOG_DEBUG, _("Got %s from %s (%s)"),
request_name[request], cl->name, cl->hostname);
}
+
+ if((cl->allow_request != ALL) && (cl->allow_request != request))
+ {
+ syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), cl->name, cl->hostname);
+ return -1;
+ }
+
if(request_handlers[request](cl))
/* Something went wrong. Probably scriptkiddies. Terminate. */
{
cl->name, cl->hostname);
return -1;
}
+cp
+ return 0;
}
/* Connection protocol:
send_challenge(R)
send_chal_reply(H)
---------------------------------------
- Any negotations about the meta protocol
- encryption go here(u).
+ send_metakey(R)
+ send_metakey(R)
---------------------------------------
send_ack(u)
send_ack(u)
int id_h(conn_list_t *cl)
{
conn_list_t *old;
- config_t *cfg;
+ config_t const *cfg;
cp
if(sscanf(cl->buffer, "%*d %as %d %lx %hd", &cl->name, &cl->protocol_version, &cl->options, &cl->port) != 4)
{
}
}
cp
- if(!(cfg = get_config_val(cl->config, publickey)))
+ if((cfg = get_config_val(cl->config, publickey)))
{
- syslog(LOG_ERR, _("No public key known for %s (%s)"), cl->name, cl->hostname);
- return -1;
- }
- else
- {
-cp
cl->rsa_key = RSA_new();
BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
BN_hex2bn(&cl->rsa_key->e, "FFFF");
}
-
+ else
+ {
+ syslog(LOG_ERR, _("No public key known for %s (%s)"), cl->name, cl->hostname);
+ return -1;
+ }
cp
return send_challenge(cl);
}
cl->hischallenge = xmalloc(len);
cp
- /* Seed the PRNG with urandom (can't afford to block) */
-
- RAND_load_file("/dev/urandom", 1024);
-
/* Copy random data to the buffer */
RAND_bytes(cl->hischallenge, len);
if(cl->status.outgoing)
cl->allow_request = ID;
else
- cl->allow_request = ACK;
+ cl->allow_request = METAKEY;
cp
return send_request(cl, "%d %s", CHAL_REPLY, hash);
*/
cp
if(cl->status.outgoing)
- return send_ack(cl);
+ return send_metakey(cl);
else
return send_id(cl);
}
+int send_metakey(conn_list_t *cl)
+{
+ char *buffer;
+ int len, x;
+cp
+ len = RSA_size(cl->rsa_key);
+
+ /* Allocate buffers for the meta key */
+
+ buffer = xmalloc(len*2+1);
+
+ if(!cl->cipher_outkey)
+ cl->cipher_outkey = xmalloc(len);
+
+ if(!cl->cipher_outctx)
+ cl->cipher_outctx = xmalloc(sizeof(*cl->cipher_outctx));
+cp
+ /* Copy random data to the buffer */
+
+ RAND_bytes(cl->cipher_outkey, len);
+
+ cl->cipher_outkey[0] &= 0x7F; /* FIXME: Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */
+
+ if(debug_lvl >= DEBUG_SCARY_THINGS)
+ {
+ bin2hex(cl->cipher_outkey, buffer, len);
+ buffer[len*2] = '\0';
+ syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer);
+ }
+
+ /* Encrypt the random data */
+
+ if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len) /* NO_PADDING because the message size equals the RSA key size and it is totally random */
+ {
+ syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
+ free(buffer);
+ return -1;
+ }
+cp
+ /* Convert the encrypted random data to a hexadecimal formatted string */
+
+ bin2hex(buffer, buffer, len);
+ buffer[len*2] = '\0';
+
+ /* Send the meta key */
+
+ if(cl->status.outgoing)
+ cl->allow_request = METAKEY;
+ else
+ cl->allow_request = ACK;
+
+ x = send_request(cl, "%d %s", METAKEY, buffer);
+ free(buffer);
+
+ EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(), cl->cipher_outkey, cl->cipher_outkey + EVP_bf_cfb()->key_len);
+cp
+ return x;
+}
+
+int metakey_h(conn_list_t *cl)
+{
+ char *buffer;
+ int len;
+cp
+ if(sscanf(cl->buffer, "%*d %as", &buffer) != 1)
+ {
+ syslog(LOG_ERR, _("Got bad METAKEY from %s (%s)"), cl->name, cl->hostname);
+ return -1;
+ }
+
+ len = RSA_size(myself->rsa_key);
+
+ /* Check if the length of the meta key is all right */
+
+ if(strlen(buffer) != len*2)
+ {
+ syslog(LOG_ERR, _("Intruder: wrong meta key length from %s (%s)"), cl->name, cl->hostname);
+ free(buffer);
+ return -1;
+ }
+
+ /* Allocate buffers for the meta key */
+
+ if(!cl->cipher_inkey)
+ cl->cipher_inkey = xmalloc(len);
+
+ if(!cl->cipher_inctx)
+ cl->cipher_inctx = xmalloc(sizeof(*cl->cipher_inctx));
+
+ /* Convert the challenge from hexadecimal back to binary */
+
+ hex2bin(buffer,buffer,len);
+
+ /* Decrypt the meta key */
+
+ if(RSA_private_decrypt(len, buffer, cl->cipher_inkey, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */
+ {
+ syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
+ free(buffer);
+ return -1;
+ }
+
+ if(debug_lvl >= DEBUG_SCARY_THINGS)
+ {
+ bin2hex(cl->cipher_inkey, buffer, len);
+ buffer[len*2] = '\0';
+ syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer);
+ }
+
+ free(buffer);
+
+ EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), cl->cipher_inkey, cl->cipher_inkey + EVP_bf_cfb()->key_len);
+
+cp
+ if(cl->status.outgoing)
+ return send_ack(cl);
+ else
+ return send_metakey(cl);
+}
+
int send_ack(conn_list_t *cl)
{
+ int x;
cp
- cl->allow_request = ACK;
+ if(cl->status.outgoing)
+ cl->allow_request = ACK;
+
+ x = send_request(cl, "%d", ACK);
+ cl->status.encryptout = 1;
cp
- return send_request(cl, "%d", ACK);
+ return x;
}
int ack_h(conn_list_t *cl)
{
- conn_list_t *old;
+ conn_list_t *old, *p;
+ subnet_t *s;
cp
/* Okay, before we active the connection, we check if there is another entry
in the connection list with the same name. If so, it presumably is an
if(debug_lvl >= DEBUG_CONNECTIONS)
syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"),
cl->name, old->hostname, cl->hostname);
- old->status.active = 0;
+
terminate_connection(old);
}
cl->allow_request = ALL;
cl->status.active = 1;
+ cl->status.decryptin = 1;
+ cl->nexthop = cl;
+ cl->cipher_pkttype = EVP_bf_cfb();
+ cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
if(debug_lvl >= DEBUG_CONNECTIONS)
syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname);
- /* Exchange information about other tinc daemons */
+cp
+ if(!cl->status.outgoing)
+ send_ack(cl);
-/* FIXME: reprogram this.
- notify_others(cl, NULL, send_add_host);
- notify_one(cl);
-*/
+ /* Send him our subnets */
+
+ for(s = myself->subnets; s; s = s->next)
+ send_add_subnet(cl, s);
+ /* And send him all the hosts and their subnets we know... */
+
+ for(p = conn_list; p; p = p->next)
+ if(p != cl && p->status.active)
+ {
+ /* Notify others of this connection */
+
+ if(p->status.meta)
+ send_add_host(p, cl);
+
+ /* Notify new connection of everything we know */
+
+ send_add_host(cl, p);
+
+ for(s = p->subnets; s; s = s->next)
+ send_add_subnet(cl, s);
+ }
cp
- if(cl->status.outgoing)
- return 0;
- else
- return send_ack(cl);
+ return 0;
}
/* Address and subnet information exchange */
-int send_add_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
+int send_add_subnet(conn_list_t *cl, subnet_t *subnet)
{
int x;
char *netstr;
cp
x = send_request(cl, "%d %s %s", ADD_SUBNET,
- other->name, netstr = net2str(subnet));
+ subnet->owner->name, netstr = net2str(subnet));
free(netstr);
cp
return x;
{
char *subnetstr;
char *name;
- conn_list_t *owner;
- subnet_t *subnet, *old;
+ conn_list_t *owner, *p;
+ subnet_t *subnet;
cp
- if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
+ if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 2)
{
syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname);
free(name); free(subnetstr);
/* If everything is correct, add the subnet to the list of the owner */
subnet_add(owner, subnet);
+
+ /* Tell the rest */
+
+ for(p = conn_list; p; p = p->next)
+ if(p->status.meta && p->status.active && p!= cl)
+ send_add_subnet(p, subnet);
cp
return 0;
}
-int send_del_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet)
+int send_del_subnet(conn_list_t *cl, subnet_t *subnet)
{
+ int x;
+ char *netstr;
+cp
+ netstr = net2str(subnet);
+ x = send_request(cl, "%d %s %s", DEL_SUBNET, subnet->owner->name, netstr);
+ free(netstr);
cp
- return send_request(cl, "%d %s %s", DEL_SUBNET, other->name, net2str(subnet));
+ return x;
}
int del_subnet_h(conn_list_t *cl)
{
char *subnetstr;
char *name;
- conn_list_t *owner;
- subnet_t *subnet, *old;
+ conn_list_t *owner, *p;
+ subnet_t *subnet;
cp
if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3)
{
/* If everything is correct, delete the subnet from the list of the owner */
subnet_del(subnet);
+
+ /* Tell the rest */
+
+ for(p = conn_list; p; p = p->next)
+ if(p->status.meta && p->status.active && p!= cl)
+ send_del_subnet(p, subnet);
cp
return 0;
}
int send_add_host(conn_list_t *cl, conn_list_t *other)
{
cp
- return send_request(cl, "%d %s %s %lx:%d %lx", ADD_HOST,
- myself->name, other->name, other->address, other->port, other->options);
+ return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST,
+ other->name, other->address, other->port, other->options);
}
int add_host_h(conn_list_t *cl)
{
- char *sender;
- conn_list_t *old, *new, *hisuplink;
+ conn_list_t *old, *new;
+ conn_list_t *p;
+
cp
new = new_conn_list();
- if(sscanf(cl->buffer, "%*d %as %as %lx:%d %lx", &sender, &new->name, &new->address, &new->port, &new->options) != 5)
+ if(sscanf(cl->buffer, "%*d %as %lx:%d %lx", &new->name, &new->address, &new->port, &new->options) != 4)
{
syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname);
return -1;
/* Check if identity is a valid name */
- if(check_id(new->name) || check_id(sender))
+ if(check_id(new->name))
{
syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
- free(sender);
+ free_conn_list(new);
return -1;
}
{
syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname);
sighup = 1;
- free(sender);
+ free_conn_list(new);
return 0;
}
-
- /* We got an ADD_HOST from ourself!? */
-
- if(!strcmp(sender, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) from ourself, restarting"), cl->name, cl->hostname);
- sighup = 1;
- free(sender);
- return 0;
- }
-
- /* Lookup his uplink */
-
- if(!(new->hisuplink = lookup_id(sender)))
- {
- syslog(LOG_ERR, _("Got ADD_HOST from %s (%s) with origin %s which is not in our connection list"),
- sender, cl->name, cl->hostname);
- free(sender);
- return -1;
- }
- free(sender);
-
/* Fill in more of the new conn_list structure */
new->hostname = hostlookup(htonl(new->address));
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);
+ free_conn_list(new);
return 0;
}
else
{
if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Removing old entry for %s (%s)"),
+ syslog(LOG_NOTICE, _("Removing old entry for %s (%s) in favour of new connection"),
old->name, old->hostname);
- old->status.active = 0;
+
terminate_connection(old);
}
}
- /* Fill in rest of conn_list structure */
-
- new->myuplink = cl;
- new->status.active = 1;
-
/* Hook it up into the conn_list */
- conn_list_add(conn_list, new);
+ conn_list_add(new);
/* Tell the rest about the new host */
-/* FIXME: reprogram this.
- notify_others(new, cl, send_add_host);
-*/
+
+ for(p = conn_list; p; p = p->next)
+ if(p->status.meta && p->status.active && p!=cl)
+ send_add_host(p, new);
+
+ /* Fill in rest of conn_list structure */
+
+ new->nexthop = cl;
+ new->status.active = 1;
+ new->cipher_pkttype = EVP_bf_cfb();
+ new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len;
+
cp
return 0;
}
int send_del_host(conn_list_t *cl, conn_list_t *other)
{
cp
- return send_request(cl, "%d %s %s %lx:%d %lx", DEL_HOST,
- myself->name, other->name, other->address, other->port, other->options);
+ return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST,
+ other->name, other->address, other->port, other->options);
}
int del_host_h(conn_list_t *cl)
{
char *name;
- char *sender;
ip_t address;
port_t port;
- int options;
- conn_list_t *old, *hisuplink;
-
+ long int options;
+ conn_list_t *old, *p;
cp
- if(sscanf(cl->buffer, "%*d %as %as %lx:%d %lx", &sender, &name, &address, &port, &options) != 5)
+ if(sscanf(cl->buffer, "%*d %as %lx:%d %lx", &name, &address, &port, &options) != 4)
{
syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"),
cl->name, cl->hostname);
/* Check if identity is a valid name */
- if(check_id(name) || check_id(sender))
+ if(check_id(name))
{
syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname);
- free(name); free(sender);
+ free(name);
return -1;
}
{
syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"),
cl->name, cl->hostname);
- free(name); free(sender);
- sighup = 1;
- return 0;
- }
-
- /* We got an ADD_HOST from ourself!? */
-
- if(!strcmp(sender, myself->name))
- {
- syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) from ourself, restarting"), cl->name, cl->hostname);
+ free(name);
sighup = 1;
- free(name); free(sender);
return 0;
}
- /* Lookup his uplink */
-
- if(!(hisuplink = lookup_id(sender)))
- {
- syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) with origin %s which is not in our connection list"),
- cl->name, cl->hostname, sender);
- free(name); free(sender);
- return -1;
- }
-
- free(sender);
-
/* Check if the new host already exists in the connnection list */
if(!(old = lookup_id(name)))
/* Check if the rest matches */
- if(address!=old->address || port!=old->port || options!=old->options || hisuplink!=old->hisuplink || cl!=old->myuplink)
+ if(address!=old->address || port!=old->port || options!=old->options || cl!=old->nexthop)
{
syslog(LOG_WARNING, _("Got DEL_HOST from %s (%s) for %s which doesn't match"), cl->name, cl->hostname, old->name);
return 0;
/* Ok, since EVERYTHING seems to check out all right, delete it */
- old->status.termreq = 1;
old->status.active = 0;
-
terminate_connection(old);
+
+ /* Tell the rest about the new host */
+
+ for(p = conn_list; p; p = p->next)
+ if(p->status.meta && p->status.active && p!=cl)
+ send_del_host(p, old);
cp
return 0;
}
}
free(errorstring);
- cl->status.termreq = 1;
terminate_connection(cl);
cp
return 0;
int termreq_h(conn_list_t *cl)
{
cp
- cl->status.termreq = 1;
terminate_connection(cl);
cp
return 0;
{
char *from_id, *to_id;
conn_list_t *from, *to;
+ char pktkey[129];
cp
if(sscanf(cl->buffer, "%*d %as %as", &from_id, &to_id) != 2)
{
if(!strcmp(to_id, myself->name))
{
- send_ans_key(myself, from, myself->cipher_pktkey);
+ bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength);
+ pktkey[myself->cipher_pktkeylength*2] = '\0';
+ send_ans_key(myself, from, pktkey);
}
else
{
free(from_id); free(to_id);
return -1;
}
- send_req_key(from, to);
+
+ if(to->status.validkey) /* Proxy keys */
+ {
+ bin2hex(to->cipher_pktkey, pktkey, to->cipher_pktkeylength);
+ pktkey[to->cipher_pktkeylength*2] = '\0';
+ send_ans_key(to, from, pktkey);
+ }
+ else
+ send_req_key(from, to);
}
free(from_id); free(to_id);
return -1;
}
- /* Check if this key request is for us */
+ /* Update origin's packet key */
- if(!strcmp(to_id, myself->name))
+ keylength = strlen(pktkey);
+
+ if(keylength != from->cipher_pktkeylength*2)
{
- /* It is for us, convert it to binary and set the key with it. */
+ syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key length"),
+ cl->name, cl->hostname, from->name);
+ free(from_id); free(to_id); free(pktkey);
+ return -1;
+ }
- keylength = strlen(pktkey);
+ if(from->cipher_pktkey)
+ free(from->cipher_pktkey);
- 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);
- free(from_id); free(to_id); free(pktkey);
- return -1;
- }
- keylength /= 2;
- hex2bin(pktkey, pktkey, keylength);
- BF_set_key(cl->cipher_pktkey, keylength, pktkey);
- }
- else
+ keylength /= 2;
+ hex2bin(pktkey, pktkey, keylength);
+ pktkey[keylength] = '\0';
+ from->cipher_pktkey = pktkey;
+
+ from->status.validkey = 1;
+ from->status.waitingforkey = 0;
+
+ if(strcmp(to_id, myself->name))
{
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);
- free(from_id); free(to_id); free(pktkey);
+ free(from_id); free(to_id);
return -1;
}
send_ans_key(from, to, pktkey);
}
- free(from_id); free(to_id); free(pktkey);
+ free(from_id); free(to_id);
cp
return 0;
}
/* Jumptable for the request handlers */
int (*request_handlers[])(conn_list_t*) = {
- id_h, challenge_h, chal_reply_h, ack_h,
+ id_h, challenge_h, chal_reply_h, metakey_h, ack_h,
status_h, error_h, termreq_h,
ping_h, pong_h,
add_host_h, del_host_h,
/* Request names */
char (*request_name[]) = {
- "ID", "CHALLENGE", "CHAL_REPLY", "ACK",
+ "ID", "CHALLENGE", "CHAL_REPLY", "METAKEY", "ACK",
"STATUS", "ERROR", "TERMREQ",
"PING", "PONG",
"ADD_HOST", "DEL_HOST",
projects / tinc / blobdiff