The functions parse_{s,c}method_line() were using
tor_addr_port_lookup() which is capable of doing DNS lookups. DNS
lookups should not be necessary when parsing {C,S}METHOD lines.
We now catch bare {s that should be on the previous line with a do,
while, if, or for, and elses that should share a line with their
preceding }.
That is,
if (foo)
{
and
if (foo) {
...
}
else
are now detected.
We should think about maybe making Tor uncrustify-clean some day,
but configuring uncrustify is an exercise in bizarreness, and
reformatting huge gobs of Tor is always painful.
The code that detected the source of a remapped address checked that
an address mapping's source was a given rewrite rule if addr_orig had
no .exit, and addr did have a .exit after processing that rule. But
addr_orig was formatted for logging: it was not the original address
at all, but rather was the address escaped for logging and possibly
replaced with "[scrubbed]".
This new logic will correctly set ADDRMAPSRC_NONE in the case when the
address starts life as a .exit address, so that AllowDotExit can work
again.
Fixes bug 6211; bugfix on 0.2.3.17-beta
It turns out this can happen. Even though there is no reason for
connections to be marked but reading, we leave them reading anyway,
so warning here is unwarranted. Let's turn that back on once we do
something sensible and disable reading when we mark. Bugfix for
6203 on Tor 0.2.3.17-beta.
Thanks to cypherpunks for pointing out the general stupidity of the
original code here.
Now it's an orthodox "goto err/done" exit path, and it isn't some
screwy thing where we stick err/done at the end of a loop and
duplicate our cleanup code.
Previously, a directory would check the latest NS consensus for
having the signatures the client wanted, and use that consensus's
valid_until time to set the HTTP lifetime. With this patch, the
directory looks at NS consensus or the microdesc consensus,
depending on what the client asked for.
I saw 72% on a test run with 26 circuits. 70% might be a little close to the
line. That, or min_circs is too low and we need to be more patient. We still
need to test/simulate more.
The defense counts the circuit failure rate for each guard for the past N
circuits. Failure is defined as the ability to complete a first hop, but not
finish completing the circuit all the way to the exit.
If the failure rate exceeds a certain amount, a notice is emitted.
If it exceeds a greater amount, a warn is emitted and the guard is disabled.
These values are governed by consensus parameters which we intend to tune as
we perform experiments and statistical simulations.
The warning message of validate_pluggable_transports_config() is
superseded by the changes in the warning message of
connection_or_connect() when the proxy credentials can't be found.
There is a bug causing busy loops in Libevent and infinite loops in
the Shadow simulator. A connection that is marked for close, wants
to flush, is held open to flush, but is rate limited (the token
bucket is empty) triggers the bug.
This commit fixes the bug. Details are below.
This currently happens on read and write callbacks when the active
socket is marked for close. In this case, Tor doesn't actually try
to complete the read or write (it returns from those methods when
marked), but instead tries to clear the connection with
conn_close_if_marked(). Tor will not close a marked connection that
contains data: it must be flushed first. The bug occurs when this
flush operation on the marked connection can not occur because the
connection is rate-limited (its write token bucket is empty).
The fix is to detect when rate limiting is preventing a marked
connection from properly flushing. In this case, it should be
flagged as read/write_blocked_on_bandwidth and the read/write events
de-registered from Libevent. When the token bucket gets refilled, it
will check the associated read/write_blocked_on_bandwidth flag, and
add the read/write event back to Libevent, which will cause it to
fire. This time, it will be properly flushed and closed.
The reason that both read and write events are both de-registered
when the marked connection can not flush is because both result in
the same behavior. Both read/write events on marked connections will
never again do any actual reads/writes, and are only useful to
trigger the flush and close the connection. By setting the
associated read/write_blocked_on_bandwidth flag, we ensure that the
event will get added back to Libevent, properly flushed, and closed.
Why is this important? Every Shadow event occurs at a discrete time
instant. If Tor does not properly deregister Libevent events that
fire but result in Tor essentially doing nothing, Libevent will
repeatedly fire the event. In Shadow this means infinite loop,
outside of Shadow this means wasted CPU cycles.
From what I can tell, this configuration is usually a mistake, and
leads people to think that all their traffic is getting proxied when
in fact practically none of it is. Resolves the issue behind "bug"
4663.
The function is not guaranteed to NUL-terminate its output. It
*is*, however, guaranteed not to generate more than two bytes per
multibyte character (plus terminating nul), so the general approach
I'm taking is to try to allocate enough space, AND to manually add a
NUL at the end of each buffer just in case I screwed up the "enough
space" thing.
Fixes bug 5909.
This feature can make Tor relays less identifiable by their use of the
mod_ssl DH group, but at the cost of some usability (#4721) and bridge
tracing (#6087) regressions.
We should try to turn this on by default again if we find that the
mod_ssl group is uncommon and/or we move to a different DH group size
(see #6088). Before we can do so, we need a fix for bugs #6087 and
Resolves ticket #5598 for now.
These stats are currently discarded, but we might as well
hard-disable them on bridges, to be clean.
Fix for bug 5824; bugfix on 0.2.1.17-rc.
Patch originally by Karsten Loesing.
Also, try to resolve some doxygen issues. First, define a magic
"This is doxygen!" macro so that we take the correct branch in
various #if/#else/#endifs in order to get the right documentation.
Second, add in a few grouping @{ and @} entries in order to get some
variables and fields to get grouped together.
This code shouldn't have any effect in 0.2.3, since we already accept
(and handle) data received while we are expecting a renegotiation.
(That's because the 0.2.3.x handshake _does_ have data there instead of
the renegotiation.)
I'm leaving it in anyway, since if it breaks anything, we'll want it
broken in master too so we can find out about it. I added an XXX023
comment so that we can come back later and fix that.
This fixes a DoS issue where a client could send so much data in 5
minutes that they exhausted the server's RAM. Fix for bug 5934 and
6007. Bugfix on 0.2.0.20-rc, which enabled the v2 handshake.
This solves bug 5283, where client traffic could get sent over the
same circuit as an anonymized connection to a directory, even if
that circuit used an exit node unsuitable for clients. By marking
the directory connection as needs_internal, we ensure that the
(non-internal!) client-traffic connection won't be sent over the
same circuit.
On Windows, getsockname() on a nonblocking apparently won't work
until the connection is done connecting. On XP, it seems to fail by
reporting success and declaring that your address is INADDR_ANY. On the
Win8 preview, though, it fails more loudly and says WSAEINVAL.
Fix for bug 5374; bugfix on 0.1.1.14-alpha.
Roger explains at
http://archives.seul.org/tor/talk/Nov-2011/msg00209.html :
"If you list your bridge as part of your family in the relay
descriptor, then everybody can learn your bridge fingerprint, and
they can look up your bridge's descriptor (and thus location) at
the bridge directory authority."
Now, we can't stop relays from listing bridges, but we can warn when
we notice a bridge listing anybody, which might help some.
This fixes bug 4657; it's a fix on 0.2.0.3-alpha, where bridges were
first introduced.
To hit this leak, you need to be a relay that gets a RESOLVE request
or an exit node getting a BEGIN or RESOLVE request. You must either
have unconfigured (and unconfigurable) nameservers, or you must have
somehow set DisableNetwork after a network request arrived but
before you managed to process it.
So, I doubt this is reached often. Still, a leak's a leak. Fix for
bug 5916; bugfix on 0.2.3.9-alpha and 0.1.2.1-alpha.
%f is correct; %lf is only needed with scanf. Apparently, on some
old BSDs, %lf is deprecated.
Didn't we do this before? Yes, we did. But we only got the
instances of %lf, not more complicated things like %.5lf . This
patch tries to get everything.
Based on a patch for 3894 by grarpamp.
These errors usually mean address exhaustion; reporting them as such
lets clients adjust their load to try other exits.
Fix for bug 4710; bugfix on 0.1.0.1-rc, which started using
END_STREAM_REASON_RESOURCELIMIT.
Silences the log message:
[warn] {BUG} _connection_mark_unattached_ap(): Bug: stream (marked at connection_edge.c:2224) sending two socks replies?
after the client triggered the "Tor is not an HTTP Proxy" response.
No additional socks reply was sent, though.
Previously, we only did this check at startup, which could lead to
us holding a guard indefinitely, and give weird results. Fixes bug
5380; bugfix on 0.2.1.14-rc.
(Patch by Roger; changes file and commit message by Nick)
Previously, we skipped everything that got invoked from
options_init_from_torrc. But some of the stuff in
options_act_reversible and options_act is actually important, like
reopening the logs.
Now, a SIGHUP always makes the effects of an options_set() happen,
even though the options haven't changed.
Fix for bug 5095; bugfix on 0.2.1.9-alpha, which introduced
__ReloadTorrcOnSIGHUP.
This would happen if the deliver window could become negative
because of an nonexistent connection. (Fortunately, _that_ can't
occur, thanks to circuit_consider_sending_sendme. Still, if we
change our windowing logic at all, we won't want this to become
triggerable.) Fix for bug 5541. Bugfix on 4a66865d, back from
0.0.2pre14. asn found this. Nice catch, asn!
This tells the windows headers to give us definitions that didn't
exist before XP -- like the ones that we need for IPv6 support.
See bug #5861. We didn't run into this issue with mingw, since
mingw doesn't respect _WIN32_WINNT as well as it should for some of
its definitions.
MSVC warns if you declare a function as having a "int foo" argument
and then implement it with a "const int foo" argument, even though
the latter "const" is not a part of the function's interface.
Instead, allow packagers to put a 'TOR_BUILD_TAG' field in the
server descriptor to indicate a platform-specific value, if they
need to. (According to weasel, this was his use for the git- tag
previously.)
This is part of 2988
This time, I follow grarpamp's suggestion and move the check for
.exit+AllowDotExit 0 to the top of connection_ap_rewrite_and_attach,
before any rewriting occurs. This way, .exit addresses are
forbidden as they arrive from a socks connection or a DNSPort
request, and not otherwise.
It _is_ a little more complicated than that, though. We need to
treat any .exit addresses whose source is TrackHostExits as meaning
that we can retry without that exit. We also need to treat any
.exit address that comes from an AutomapHostsOnResolve operation as
user-provided (and thus forbidden if AllowDotExits==0), so that
transitioning from AllowDotExits==1 to AllowDotExits==0 will
actually turn off automapped .exit addresses.
This patch changes the total serverdesc threshold from 25% to 75%
and the exit threshold from 33% to 50%. The goal is to make
initially constructed circuits less horrible, and to make initial
less awful (since fetching directory information in parallel with
whatever the user is trying to do can hurt their performance).
Implements ticket 3196.
We were doing an O(n) strlen in router_get_extrainfo_hash() for
every one we tried to parse. Instead, have
router_get_extrainfo_hash() take the length of the extrainfo as an
argument, so that when it's called from
extrainfo_parse_from_string(), it doesn't do a strlen() over the
whole pile of extrainfos.
If the authorities agreed on a sufficiently bad bwweightscale value
(<=0 or == INT32_MAX), the bandwidth algorithm could make the voters
assert while computing the consensus.
Fix for bug5786; bugfix on 0.2.2.17-alpha
This is how IPv6 says "0.0.0.0" and something we will have to
translate into a globally reachable address before putting it in a
descriptor.
The fix is a short term solution until a real one is implemented.
Closes#5146.
Fixes bug #4528 "read_to_buf_tls(): Inconsistency in code".
This check was added back in 0.1.0.3-rc, but somehow we forgot to
leave it in when we refactored read_to_buf_tls in 0.1.0.5-rc.
(patch by Arturo; commit message and changes file by nickm)
Instead of checking for 'rejected' and calling everything else okay,
let's check for 'outdated' and call everythign else a problem. This
way we don't risk missing future errors so much.
When logging a message that _looks_ like an error message at info, we
should mention that it isn't really a problem.
Previously, we would reset it at the drop of a hat -- every time a second
passes without any of the intro-point circs already launched for the
service failing.
Fixes bug 4607.
In general, whenever we can, we should be doing
base64_decode(buf, sizeof(buf), s, strlen(s)),
and not
base_64_decode(buf, expr1, s, expr2)
where we hope that expr1 is a good name for the size of buf and expr2
is a good formula for the length of the base64 expression in s.
* Document fmt_addr_impl() and friends.
* Parenthesize macro arguments.
* Rename get_first_listener_addrport_for_pt() to
get_first_listener_addrport_string().
* Handle port_cfg_t with no_listen.
* Handle failure of router_get_active_listener_port_by_type().
* Add an XXX to router_get_active_listener_port_by_type().
This is just refactoring work here. The old logic was kind of
convoluted, especially after the bug 5572 fix. We don't actually need to
distinguish so many cases here. Dropping detection of the
"!old_options || !old_options->DynamicDHGroups" case is fine because
that's the same that we'd do for clients.
Also add a changes file for bug 5572.
The message only means that we're publishing a new descriptor when we
are actually in some kind of server mode, and publication is on.
Fix for bug 3942; bugfix on 0.2.3.2-alpha.
This fixes a side-channel attack on the (fortunately unused!)
BridgePassword option for bridge authorities. Fix for bug 5543;
bugfix on 0.2.0.14-alpha.
Introduce get_first_listener_addrport_for_pt() which returns a string
containing the addrport of the first listener we could find. Use it to
form the TOR_PT_ORPORT managed proxy protocol line.
This is ticket 2479. Roger's original explanation was:
We have a series of bugs where relays publish a descriptor within
12 hours of their last descriptor, but the authorities drop it
because it's not different "enough" from the last one and it's
too close to the last one.
The original goal of this idea was to a) reduce the number of new
descriptors authorities accept (and thus have to store) and b)
reduce the total number of descriptors that clients and mirrors
fetch. It's a defense against bugs where relays publish a new
descriptor every minute.
Now that we're putting out one consensus per hour, we're doing
better at the total damage that can be caused by 'b'.
There are broader-scale design changes that would help here, and
we've had a trac entry open for years about how relays should
recognize that they're not in the consensus, or recognize when
their publish failed, and republish sooner.
In the mean time, I think we should change some of the parameters
to make the problem less painful.
When we started RefuseUnknownExits back in 0.2.2.11-alpha, we
started making exits act like they cache directory info (since they
need an up-to-date idea of who is really a router). But this
included fetching needless (unrecognized) authorities' certs, which
doesn't make any sense for them.
This is related to, but not necessarily the same as, the issue that
Ian reported for bug #2297.
(This patch is based on a patch from a user who I believe has asked
not to be named. If I'm wrong about that, please add the
appropriate name onto the changelog.)
A previous commit in the 5527 branch had moved
router_get_mutable_by_digest(digest_rcvd) to happen before we did
tor_assert(digest_rcvd), which would have defeated the purpose of
the assert.
Specifically, I believe it dates back to when extend cells had address:port
but no digest in them. The special edge case is certainly not worth the
complexity these days.
This mitigates an attack proposed by wanoskarnet, in which all of a
client's bridges collude to restrict the exit nodes that the client
knows about. Fixes bug 5343.
In the distant past, connection_handle_read() could be called when there
are pending bytes in the TLS object during the main loop. The design
since then has been to always read all pending bytes immediately, so
read events only trigger when the socket actually has bytes to read.
Resolves bug 5324.
The invariant is: unconfigured_proxies_n is exactly the number of
managed_proxy_t not in state PT_PROTO_COMPLETED.
To maintain this, we need to stop overloading unconfigured_proxies_n
to also count managed_proxy_t items that are in PT_PROTO_COMPLETED but
which might need relaunching. To make it so we can detect those, we
introduce another variable.
This commit also adds a function to assert that we haven't broken the
invariant.
Fix for bug 5084; bugfix on 0.2.3.6-alpha, I think.
In some cases, we solve this by doing a SMARTLIST_DEL_CURRENT before
calling managed_proxy_destroy. But for a trickier one, we just make a
copy of the list before iterating over it, so that changes to the
manage proxy list don't hurt our iteration.
This could be related to bug 5084.
in Makefile.am, we used it without quoting it, causing build failure if
your openssl/sed/sha1sum happened to live in a directory with a space in
it (very common on windows)
If we don't do this, [::] can be interpreted to mean all v4 and all
v6 addresses. Found by dcf. Fixes bug 4760. See RFC 3493 section
5.3 for more info.
There was one MS_WINDOWS that remained because it wasn't on a macro
line; a few remaining uses (and the definition!) in configure.in;
and a now-nonsensical stanza of eventdns_tor.h that previously
defined 'WIN32' if it didn't exist.
This commit is completely mechanical; I used this perl script to make it:
#!/usr/bin/perl -w -i.bak -p
if (/^\s*\#/) {
s/MS_WINDOWS/_WIN32/g;
s/\bWIN32\b/_WIN32/g;
}
Previously the client would ask the bridge for microdescriptors, which are
only supported in 0.2.3.x and later, and then fail to bootstrap when it
didn't get the answers it wanted. Fixes bug 4013; bugfix on 0.2.3.2-alpha.
The fix here is to revert to using normal descriptors if any of our
bridges are known to not support microdescs. This is not ideal, a) because
we'll start downloading a microdesc consensus as soon as we get a bridge
descriptor, and that will waste time if we later get a bridge descriptor
that tells us we don't like microdescriptors; and b) by changing our mind
we're leaking to our other bridges that we have an old-version bridge.
The alternate fix would have been to change
we_use_microdescriptors_for_circuits() to ask if *any* of our bridges
can support microdescriptors, and then change the directory logic that
picks a bridge to only select from those that do. For people living in
the future, where 0.2.2.x is obsolete, there won't be a difference.
Note that in either of these potential fixes, we have risk of oscillation
if our one funny-looking bridges goes away / comes back.
These were found by looking for tor_snprintf() instances that were
preceeded closely by tor_malloc(), though I probably converted some
more snprintfs as well.
(In every case, make sure that the length variable (if any) is
removed, renamed, or lowered, so that anything else that might have
assumed a longer buffer doesn't exist.)
These were found by looking for tor_snprintf() instances that were
followed closely by tor_strdup(), though I probably converted some
other snprintfs as well.
(To ensure correctness, in every case, make sure that the temporary
variable is deleted, renamed, or lowered in scope, so we can't have
any bugs related to accidentally relying on the no-longer-filled
variable.)
Fixes bug #4897, not yet in any release.
Using n_circ_id alone here (and below, when n_conn is NULL) really sucks,
but that's a separate bug which will need a changes/ file.
When we have an effective bandwidthrate configured so that we cannot
exceed our bandwidth limit in one accounting interval, don't disable
advertising the dirport. Implements ticket 2434.
We used to do this as a workaround for older Tors, but now it's never
the correct thing to do (especially since anything that didn't
understand RELAY_EARLY is now deprecated hard).
This patch should make us reject every Tor that was vulnerable to
CVE-2011-0427. Additionally, it makes us reject every Tor that couldn't
handle RELAY_EARLY cells, which helps with proposal 110 (#4339).
Back in #1240, r1eo linked to information about how this could happen
with older Linux kernels in response to nmap. Bugs #4545 and #4547
are about how our approach to trying to deal with this condition was
broken and stupid. Thanks to wanoskarnet for reminding us about #1240.
This is a fix for the abovementioned bugs, and is a bugfix on
0.1.0.3-rc.
Preprocessor directives should not be put inside the arguments
of a macro. This is not supported on older GCC releases (< 3.3)
thus broke compilation on Haiku (running gcc2).
It's inefficient, but the more efficient solution (only try to attach
streams aiming for this HS) would require far more complexity for a gain
that should be tiny.
The client's anonymity when accessing a non-HS address in tor2web-mode
would be easily nuked by inserting an inline image with a .onion URL, so
don't even pretend to access non-HS addresses through Tor.
The Tor2webMode torrc option is still required to run a Tor client in
'tor2web mode', but now it can't be turned on at runtime in a normal build
of Tor. (And a tor2web build of Tor can't be used as a normal Tor client,
so we don't have to worry as much about someone distributing packages with
this particular pistol accessible to normal users.)
This resolves a loop warning on "MapAddress *.example.com
example.com", makes the rewrite log messages correct, and fixes the
behavior of "MapAddress *.a *.b" when just given "a" as an input.
MapAddress *.torproject.org torproject.org would have been interpreted
as a map from a domain to itself, and would have cleared the mapping.
Now we require not only a match of domains, but of wildcards.
Incidentally, we've got 30969 lines in master with a comma
in them, of which 1995 have a comma followed by a non-newline,
non-space character. So about 93% of our commas are right,
but we have a substantial number of "crowded" lines.
It might be nice to support this someday, but for now it would fail
with an infinite remap cycle. (If I say "remap * *.foo.exit",
then example.com ->
example.com.foo.exit ->
example.com.foo.exit.foo.exit ->
example.com.foo.exit.foo.exit.foo.exit -> ...)
In this new representation for wildcarded addresses, there are no
longer any 'magic addresses': rather, "a.b c.d", "*.a.b c.d" and
"*.a.b *.c.d" are all represented by a mapping from "a.b" to "c.d". we
now distinguish them by setting bits in the addressmap_entry_t
structure, where src_wildcard is set if the source address had a
wildcard, and dst_wildcard is set if the target address had a
wildcard.
This lets the case where "*.a.b *.c.d" or "*.a.b c.d" remap the
address "a.b" get handled trivially, and lets us simplify and improve
the addressmap_match_superdomains implementation: we can now have it
run in O(parts of address) rather than O(entries in addressmap).
1. Only allow '*.' in MapAddress expressions. Ignore '*ample.com' and '.example.com'.
This has resulted in a slight refactoring of config_register_addressmaps.
2. Add some more detail to the man page entry for AddressMap.
3. Fix initialization of a pointer to NULL rather than 0.
4. Update the unit tests to cater for the changes in 1 and test more explicitly for
recursive mapping.
1. Implement the following mapping rules:
MapAddress a.b.c d.e.f # This is what we have now
MapAddress .a.b.c d.e.f # Replaces any address ending with .a.b.c with d.e.f
MapAddress .a.b.c .d.e.f # Replaces the .a.b.c at the end of any addr with .d.e.f
(Note that 'a.b.c .d.e.f' is invalid, and will be rejected.)
2. Add tests for the new rules.
3. Allow proper wildcard annotation, i.e. '*.d.e' '.d.e' will still work.
4. Update addressmap_entry_t with an is_wildcard member.
This keeps the IP address and TCP for a given OR port together,
reducing the risk of using an address for one address family with a
port of another.
Make node_get_addr() a wrapper function for compatibility.
This is not as conservative as we could do it, f.ex. by looking at the
connection and only do this for connections to bridges. A non-bridge
should never have anything else than its primary IPv4 address set
though, so I think this is safe.
Don't touch the string representation in routerinfo_t->address.
Also, set or clear the routerinfo_t->ipv6_preferred flag based on the
address family of the bridge.
Comments below focus on changes, see diff for added code.
New type tor_addr_port_t holding an IP address and a TCP/UDP port.
New flag in routerinfo_t, ipv6_preferred. This should go in the
node_t instead but not now.
Replace node_get_addr() with
- node_get_prim_addr() for primary address, i.e. IPv4 for now
- node_get_pref_addr() for preferred address, IPv4 or IPv6.
Rename node_get_addr_ipv4h() node_get_prim_addr_ipv4h() for
consistency. The primary address will not allways be an IPv4 address.
Same for node_get_orport() -> node_get_prim_orport().
Rewrite node_is_a_configured_bridge() to take all OR ports into account.
Extend argument list to extend_info_from_node and
extend_info_from_router with a flag indicating if we want to use the
routers primary address or the preferred address. Use the preferred
address in as few situtations as possible for allowing clients to
connect to bridges over IPv6.
This code handles the new ORPort options, and incidentally makes all
remaining port types use the new port configuration systems.
There are some rough edges! It doesn't do well in the case where your
Address says one thing but you say to Advertise another ORPort. It
doesn't handle AllAddrs. It doesn't actually advertise anything besides
the first listed advertised IPv4 ORPort and DirPort. It doesn't do
port forwarding to them either.
It's not tested either, it needs more documentation, and it probably
forgets to put the milk back in the refrigerator.
Some controllers want this so they can mess with Tor's configuration
for a while via the control port before actually letting Tor out of
the house.
We do this with a new DisableNetwork option, that prevents Tor from
making any outbound connections or binding any non-control
listeners. Additionally, it shuts down the same functionality as
shuts down when we are hibernating, plus the code that launches
directory downloads.
To make sure I didn't miss anything, I added a clause straight to
connection_connect, so that we won't even try to open an outbound
socket when the network is disabled. In my testing, I made this an
assert, but since I probably missed something, I've turned it into a
BUG warning for testing.
This will mainly help distributors by giving a way to set system or package
defaults that a user can override, and that a later package can replace.
No promises about the particular future location or semantics for this:
we will probably want to tweak it some before 0.2.3.x-rc
The file is searched for in CONFDIR/torrc-defaults , which can be
overridden with the "--defaults-torrc" option on the command line.
This starts an effort to refactor torrc handling code to make it easier
to live with. It makes it possible to override exit policies from the
command line, and possible to override (rather than append to) socksport
lists from the command line.
It'll be necessary to make a "base" torrc implementation work at all.
Instead of only writing the dynamic DH prime modulus to a file, write
the whole DH parameters set for forward compatibility. At the moment
we only accept '2' as the group generator.
The DH parameters gets stored in base64-ed DER format to the
'dynamic_dh_params' file.
Let's *not* expose more cross-platform-compatibility structures, or
expect code to use them right.
Also, don't fclose() stdout_handle and stdin_handle until we do
tor_process_handle_destroy, or we risk a double-fclose.
We used to do init_keys() if DynamicDHGroups changed after a HUP, so
that the dynamic DH modulus was stored on the disk. Since we are now
doing dynamic DH modulus storing in crypto.c, we can simply initialize
the TLS context and be good with it.
Introduce a new function router_initialize_tls_context() which
initializes the TLS context and use it appropriately.
