- /* Decrypt the challenge */
-
- if(RSA_private_decrypt(len, buffer, cl->mychallenge, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */
- {
- syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname);
- free(buffer);
- return -1;
- }
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(cl->mychallenge, buffer, len);
- buffer[len*2] = '\0';
- syslog(LOG_DEBUG, _("Received random challenge (unencrypted): %s"), buffer);
- }
-
- free(buffer);
-
- /* Rest is done by send_chal_reply() */
-cp
- return send_chal_reply(cl);
-}
-
-int send_chal_reply(conn_list_t *cl)
-{
- char hash[SHA_DIGEST_LENGTH*2+1];
-cp
- if(!cl->mychallenge)
- {
- syslog(LOG_ERR, _("Trying to send CHAL_REPLY to %s (%s) without a valid CHALLENGE"), cl->name, cl->hostname);
- return -1;
- }
-
- /* Calculate the hash from the challenge we received */
-
- SHA1(cl->mychallenge, RSA_size(myself->rsa_key), hash);
-
- /* Convert the hash to a hexadecimal formatted string */
-
- bin2hex(hash,hash,SHA_DIGEST_LENGTH);
- hash[SHA_DIGEST_LENGTH*2] = '\0';
-
- /* Send the reply */
-
- if(cl->status.outgoing)
- cl->allow_request = ID;
- else
- cl->allow_request = METAKEY;
-
-cp
- return send_request(cl, "%d %s", CHAL_REPLY, hash);
-}
-
-int chal_reply_h(conn_list_t *cl)
-{
- char *hishash;
- char myhash[SHA_DIGEST_LENGTH];
-cp
- if(sscanf(cl->buffer, "%*d %as", &hishash) != 1)
- {
- syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->name, cl->hostname);
- free(hishash);
- return -1;
- }
-
- /* Check if the length of the hash is all right */
-
- if(strlen(hishash) != SHA_DIGEST_LENGTH*2)
- {
- syslog(LOG_ERR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->name, cl->hostname);
- free(hishash);
- return -1;
- }
-
- /* Convert the hash to binary format */
-
- hex2bin(hishash, hishash, SHA_DIGEST_LENGTH);
-
- /* Calculate the hash from the challenge we sent */
-
- SHA1(cl->hischallenge, RSA_size(cl->rsa_key), myhash);
-
- /* Verify the incoming hash with the calculated hash */
-
- if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH))
- {
- syslog(LOG_ERR, _("Intruder: wrong challenge reply from %s (%s)"), cl->name, cl->hostname);
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(myhash, hishash, SHA_DIGEST_LENGTH);
- hishash[SHA_DIGEST_LENGTH*2] = '\0';
- syslog(LOG_DEBUG, _("Expected challenge reply: %s"), hishash);
- }
- free(hishash);
- return -1;
- }
-
-
- free(hishash);
-
- /* Identity has now been positively verified.
- If we are accepting this new connection, then send our identity,
- if we are making this connecting, acknowledge.
- */
-cp
- if(cl->status.outgoing)
- 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
- if(cl->status.outgoing)
- cl->allow_request = ACK;
-
- x = send_request(cl, "%d", ACK);
- cl->status.encryptout = 1;
-cp
- return x;
-}
-
-int ack_h(conn_list_t *cl)
-{
- 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
- 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->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);
-
-cp
- if(!cl->status.outgoing)
- send_ack(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
- return 0;
-}
-
-/* Address and subnet information exchange */
-
-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,
- subnet->owner->name, netstr = net2str(subnet));
- free(netstr);
-cp
- return x;
-}
-
-int add_subnet_h(conn_list_t *cl)
-{
- char *subnetstr;
- char *name;
- conn_list_t *owner, *p;
- subnet_t *subnet;
-cp
- 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);
- 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);
- free(name); free(subnetstr);
- return -1;
- }
-
- /* Check if subnet string is valid */
-
- if(!(subnet = str2net(subnetstr)))
- {
- syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname);
- free(name); free(subnetstr);
- return -1;
- }
-
- free(subnetstr);
-
- /* 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);
- free(name);
- sighup = 1;
- return 0;
- }
-
- /* Check if the owner of the new subnet is in the connection list */
-
- if(!(owner = lookup_id(name)))
- {
- syslog(LOG_ERR, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"),
- name, cl->name, cl->hostname);
- free(name);
- return -1;
- }
-
- /* 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, 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 x;
-}
-
-int del_subnet_h(conn_list_t *cl)