along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: protocol.c,v 1.28.4.82 2001/02/26 11:37:20 guus Exp $
+ $Id: protocol.c,v 1.28.4.89 2001/05/24 21:52:26 guus Exp $
*/
#include "config.h"
#include "system.h"
+int mykeyused = 0;
+
int check_id(char *id)
{
int i;
cp
if(sscanf(cl->buffer, "%d", &request) == 1)
{
- if((request < 0) || (request > 255) || (request_handlers[request] == NULL))
+ if((request < 0) || (request >= LAST) || (request_handlers[request] == NULL))
{
syslog(LOG_ERR, _("Unknown request from %s (%s)"),
cl->name, cl->hostname);
return send_metakey(cl);
}
+int ack_h(connection_t *cl)
+{
+ config_t const *cfg;
+ connection_t *old, *p;
+ subnet_t *subnet;
+ avl_node_t *node, *node2;
+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
+ old connection that has timed out but we don't know it yet.
+ */
+
+ 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"),
+ cl->name, old->hostname, cl->hostname);
+
+ terminate_connection(old);
+ }
+
+ /* Activate this connection */
+
+ cl->allow_request = ALL;
+ cl->status.active = 1;
+ cl->nexthop = cl;
+ cl->cipher_pkttype = EVP_bf_cbc();
+ 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);
+
+cp
+ /* Check some options */
+
+ if((cfg = get_config_val(cl->config, config_indirectdata)))
+ {
+ if(cfg->data.val == stupid_true)
+ cl->options |= OPTION_INDIRECT;
+ }
+
+ if((cfg = get_config_val(cl->config, config_tcponly)))
+ {
+ if(cfg->data.val == stupid_true)
+ cl->options |= OPTION_TCPONLY;
+ }
+
+ /* Send him our subnets */
+
+ for(node = myself->subnet_tree->head; node; node = node->next)
+ {
+ subnet = (subnet_t *)node->data;
+ send_add_subnet(cl, subnet);
+ }
+
+ /* And send him all the hosts and their subnets we know... */
+
+ for(node = connection_tree->head; node; node = node->next)
+ {
+ p = (connection_t *)node->data;
+
+ 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(node2 = p->subnet_tree->head; node2; node2 = node2->next)
+ {
+ subnet = (subnet_t *)node2->data;
+ send_add_subnet(cl, subnet);
+ }
+ }
+ }
+cp
+ return 0;
+}
+
int send_challenge(connection_t *cl)
{
char *buffer;
RAND_bytes(cl->cipher_outkey, len);
- cl->cipher_outkey[0] &= 0x0F; /* Make sure that the random data is smaller than the modulus of the RSA key */
+ /* The message we send must be smaller than the modulus of the RSA key.
+ By definition, for a key of k bits, the following formula holds:
+
+ 2^(k-1) <= modulus < 2^(k)
+
+ Where ^ means "to the power of", not "xor".
+ This means that to be sure, we must choose our message < 2^(k-1).
+ This can be done by setting the most significant bit to zero.
+ */
+
+ cl->cipher_outkey[0] &= 0x7F;
if(debug_lvl >= DEBUG_SCARY_THINGS)
{
syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer);
}
- /* Encrypt the random data */
+ /* Encrypt the random data
+
+ We do not use one of the PKCS padding schemes here.
+ This is allowed, because we encrypt a totally random string
+ with a length equal to that of the modulus of the RSA key.
+ */
- 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 */
+ if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len)
{
syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname);
free(buffer);
return send_challenge(cl);
}
-int ack_h(connection_t *cl)
-{
- config_t const *cfg;
- connection_t *old, *p;
- subnet_t *subnet;
- avl_node_t *node, *node2;
-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
- old connection that has timed out but we don't know it yet.
- */
-
- 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"),
- cl->name, old->hostname, cl->hostname);
-
- terminate_connection(old);
- }
-
- /* Activate this connection */
-
- cl->allow_request = ALL;
- cl->status.active = 1;
- cl->nexthop = cl;
- cl->cipher_pkttype = EVP_bf_cbc();
- 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);
-
-cp
- /* Check some options */
-
- if((cfg = get_config_val(cl->config, config_indirectdata)))
- {
- if(cfg->data.val == stupid_true)
- cl->options |= OPTION_INDIRECT;
- }
-
- if((cfg = get_config_val(cl->config, config_tcponly)))
- {
- if(cfg->data.val == stupid_true)
- cl->options |= OPTION_TCPONLY;
- }
-
- /* Send him our subnets */
-
- for(node = myself->subnet_tree->head; node; node = node->next)
- {
- subnet = (subnet_t *)node->data;
- send_add_subnet(cl, subnet);
- }
- /* And send him all the hosts and their subnets we know... */
-
- for(node = connection_tree->head; node; node = node->next)
- {
- p = (connection_t *)node->data;
-
- 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(node2 = p->subnet_tree->head; node2; node2 = node2->next)
- {
- subnet = (subnet_t *)node2->data;
- send_add_subnet(cl, subnet);
- }
- }
- }
-cp
- return 0;
-}
-
/* Address and subnet information exchange */
int send_add_subnet(connection_t *cl, subnet_t *subnet)
char *netstr;
char *owner;
cp
- if(cl->options & OPTION_INDIRECT)
+ if((cl->options | myself->options | subnet->owner->options) & OPTION_INDIRECT)
owner = myself->name;
else
owner = subnet->owner->name;
int send_add_host(connection_t *cl, connection_t *other)
{
cp
- if(!(cl->options & OPTION_INDIRECT))
+ if(!((cl->options | myself->options | other->options) & OPTION_INDIRECT))
return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST,
other->name, other->address, other->port, other->options);
+ else
+ return 0;
}
int add_host_h(connection_t *cl)
cp
new = new_connection();
- if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%d %lx", name, &new->address, &new->port, &new->options) != 4)
+ if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx", name, &new->address, &new->port, &new->options) != 4)
{
syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname);
return -1;
int send_del_host(connection_t *cl, connection_t *other)
{
cp
- if(!(cl->options & OPTION_INDIRECT))
+ if(!((cl->options | myself->options) & OPTION_INDIRECT))
return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST,
other->name, other->address, other->port, other->options);
+ else
+ return 0;
}
int del_host_h(connection_t *cl)
{
char name[MAX_STRING_SIZE];
- ip_t address;
+ ipv4_t address;
port_t port;
long int options;
connection_t *old, *p;
avl_node_t *node;
cp
- if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%d %lx", name, &address, &port, &options) != 4)
+ if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx", name, &address, &port, &options) != 4)
{
syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"),
cl->name, cl->hostname);
int send_ping(connection_t *cl)
{
+ char salt[SALTLEN*2+1];
cp
cl->status.pinged = 1;
cl->last_ping_time = time(NULL);
+ RAND_bytes(salt, SALTLEN);
+ bin2hex(salt, salt, SALTLEN);
cp
- return send_request(cl, "%d", PING);
+ return send_request(cl, "%d %s", PING, salt);
}
int ping_h(connection_t *cl)
int send_pong(connection_t *cl)
{
+ char salt[SALTLEN*2+1];
+cp
+ RAND_bytes(salt, SALTLEN);
+ bin2hex(salt, salt, SALTLEN);
cp
- return send_request(cl, "%d", PONG);
+ return send_request(cl, "%d %s", PONG, salt);
}
int pong_h(connection_t *cl)
connection_t *p;
avl_node_t *node;
cp
- for(node = connection_tree->head; node; node = node->next)
+ /* Only send this message if some other daemon requested our key previously.
+ This reduces unnecessary key_changed broadcasts.
+ */
+
+ if(mykeyused)
{
- p = (connection_t *)node->data;
- if(p != cl && p->status.meta && p->status.active)
- if(!(p->options & OPTION_INDIRECT) || from == myself)
- send_request(p, "%d %s", KEY_CHANGED, from->name);
- }
+ for(node = connection_tree->head; node; node = node->next)
+ {
+ p = (connection_t *)node->data;
+ if(p != cl && p->status.meta && p->status.active)
+ if(!(p->options & OPTION_INDIRECT) || from == myself)
+ send_request(p, "%d %s", KEY_CHANGED, from->name);
+ }
+ mykeyused = 0;
+ }
cp
return 0;
}
from->status.validkey = 0;
from->status.waitingforkey = 0;
- send_key_changed(from, cl);
+ if(!(from->options | cl->options | myself->options) & OPTION_INDIRECT)
+ send_key_changed(from, cl);
cp
return 0;
}
/* Check if this key request is for us */
- if(!strcmp(to_id, myself->name))
+ if(!strcmp(to_id, myself->name)) /* Yes, send our own key back */
{
bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength);
pktkey[myself->cipher_pktkeylength*2] = '\0';
send_ans_key(myself, from, pktkey);
+ mykeyused = 1;
}
else
{
int send_tcppacket(connection_t *cl, vpn_packet_t *packet)
{
int x;
-
+cp
x = send_request(cl->nexthop, "%d %hd", PACKET, packet->len);
if(x)
vpn_packet_t packet;
char *p;
int todo, x;
-
- if(sscanf(cl->buffer, "%*d %hd", packet.len) != 1)
+cp
+ if(sscanf(cl->buffer, "%*d %hd", &packet.len) != 1)
{
syslog(LOG_ERR, _("Got bad PACKET from %s (%s)"), cl->name, cl->hostname);
return -1;
p = packet.data;
todo = packet.len;
-
+
while(todo)
{
x = read(cl->meta_socket, p, todo);
if(x==0)
syslog(LOG_NOTICE, _("Connection closed by %s (%s)"), cl->name, cl->hostname);
else
- if(errno==EINTR)
+ if(errno==EINTR || errno==EAGAIN) /* FIXME: select() or poll() or reimplement this evil hack */
continue;
else
syslog(LOG_ERR, _("Error during reception of PACKET from %s (%s): %m"), cl->name, cl->hostname);
p += x;
}
- return receive_packet(cl, &packet);
+ receive_packet(cl, &packet);
+cp
+ return 0;
}
/* Jumptable for the request handlers */
projects / tinc / blobdiff