Refuse to make direct connections to private OR addresses

Refuse connection requests to private OR addresses unless
ExtendAllowPrivateAddresses is set. Previously, tor would
connect, then refuse to send any cells to a private address.

Fixes bugs 17674 and 8976; bugfix on b7c172c9ec (28 Aug 2012)
Original bug 6710, released in 0.2.3.21-rc and an 0.2.2 maint
release.

Patch by "teor".
This commit is contained in:
teor (Tim Wilson-Brown) 2015-11-25 03:11:15 +11:00
parent 6cdd024c94
commit 23b088907f
2 changed files with 13 additions and 3 deletions

View File

@ -1898,9 +1898,11 @@ is non-zero):
(Default: 1)
[[ExtendAllowPrivateAddresses]] **ExtendAllowPrivateAddresses** **0**|**1**::
When this option is enabled, Tor routers allow EXTEND request to
localhost, RFC1918 addresses, and so on. This can create security issues;
you should probably leave it off. (Default: 0)
When this option is enabled, Tor will connect to localhost, RFC1918
addresses, and so on. In particular, Tor will make direct connections, and
Tor routers allow EXTEND requests, to these private addresses. This can
create security issues; you should probably leave it off.
(Default: 0)
[[MaxMemInQueues]] **MaxMemInQueues** __N__ **bytes**|**KB**|**MB**|**GB**::
This option configures a threshold above which Tor will assume that it

View File

@ -498,6 +498,14 @@ circuit_handle_first_hop(origin_circuit_t *circ)
tor_assert(firsthop);
tor_assert(firsthop->extend_info);
/* XX/teor - does tor ever need build a circuit directly to itself? */
if (tor_addr_is_internal(&firsthop->extend_info->addr, 0) &&
!get_options()->ExtendAllowPrivateAddresses) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Client asked me to connect directly to a private address");
return -END_CIRC_REASON_TORPROTOCOL;
}
/* now see if we're already connected to the first OR in 'route' */
log_debug(LD_CIRC,"Looking for firsthop '%s'",
fmt_addrport(&firsthop->extend_info->addr,