Nick Mathewson [Thu, 6 Dec 2012 03:34:49 +0000 (22:34 -0500)]
Teach cpuworker and others about create_cell_t and friends
The unit of work sent to a cpuworker is now a create_cell_t; its
response is now a created_cell_t. Several of the things that call or
get called by this chain of logic now take create_cell_t or
created_cell_t too.
Since all cpuworkers are forked or spawned by Tor, they don't need a
stable wire protocol, so we can just send structs. This saves us some
insanity, and helps p
Nick Mathewson [Wed, 5 Dec 2012 02:39:54 +0000 (21:39 -0500)]
Rename handshake_digest to rend_circ_nonce
The handshake_digest field was never meaningfully a digest *of* the
handshake, but rather is a digest *from* the handshake that we exapted
to prevent replays of ESTABLISH_INTRO cells. The ntor handshake will
generate it as more key material rather than taking it from any part
of the circuit handshake reply..
Nick Mathewson [Tue, 4 Dec 2012 21:09:52 +0000 (16:09 -0500)]
Split onion.[ch] into onion{,_fast,_tap}.[ch]
I'm going to want a generic "onionskin" type and set of wrappers, and
for that, it will be helpful to isolate the different circuit creation
handshakes. Now the original handshake is in onion_tap.[ch], the
CREATE_FAST handshake is in onion_fast.[ch], and onion.[ch] now
handles the onion queue.
This commit does nothing but move code and adjust header files.
Here we try to handle curve25519 onion keys from generating them,
loading and storing them, publishing them in our descriptors, putting
them in microdescriptors, and so on.
This commit is untested and probably buggy like whoa
Nick Mathewson [Tue, 4 Dec 2012 20:57:16 +0000 (15:57 -0500)]
Move curve25519 keypair type to src/common; give it functions
This patch moves curve25519_keypair_t from src/or/onion_ntor.h to
src/common/crypto_curve25519.h, and adds new functions to generate,
load, and store keypairs.
Nick Mathewson [Tue, 4 Dec 2012 04:31:07 +0000 (23:31 -0500)]
Refactor strong os-RNG into its own function
Previously, we only used the strong OS entropy source as part of
seeding OpenSSL's RNG. But with curve25519, we'll have occasion to
want to generate some keys using extremely-good entopy, as well as the
means to do so. So let's!
This patch refactors the OS-entropy wrapper into its own
crypto_strongest_rand() function, and makes our new
curve25519_secret_key_generate function try it as appropriate.
Nick Mathewson [Tue, 4 Dec 2012 02:24:21 +0000 (21:24 -0500)]
Implementat the ntor handshake
The ntor handshake--described in proposal 216 and in a paper by
Goldberg, Stebila, and Ustaoglu--gets us much better performance than
our current approach.
Nick Mathewson [Mon, 3 Dec 2012 20:44:21 +0000 (15:44 -0500)]
Add a wrapper around, and test and build support for, curve25519.
We want to use donna-c64 when we have a GCC with support for
64x64->uint128_t multiplying. If not, we want to use libnacl if we
can, unless it's giving us the unsafe "ref" implementation. And if
that isn't going to work, we'd like to use the
portable-and-safe-but-slow 32-bit "donna" implementation.
We might need more library searching for the correct libnacl,
especially once the next libnacl release is out -- it's likely to have
bunches of better curve25519 implementations.
I also define a set of curve25519 wrapper functions, though it really
shouldn't be necessary.
We should eventually make the -donna*.c files get build with
-fomit-frame-pointer, since that can make a difference.
Nick Mathewson [Mon, 3 Dec 2012 17:20:05 +0000 (12:20 -0500)]
Implement HKDF from RFC5869
This is a customizable extract-and-expand HMAC-KDF for deriving keys.
It derives from RFC5869, which derives its rationale from Krawczyk,
H., "Cryptographic Extraction and Key Derivation: The HKDF Scheme",
Proceedings of CRYPTO 2010, 2010, <http://eprint.iacr.org/2010/264>.
I'm also renaming the existing KDF, now that Tor has two of them.
This is the key derivation scheme specified in ntor.
Nick Mathewson [Sun, 18 Nov 2012 22:15:41 +0000 (17:15 -0500)]
Initialize ipv{4,6}_traffic_ok in entry_connection_new
This one is necessary for sending BEGIN cells with sane flags when
self-testing a directory port. All real entry connections were
getting their ipv{4,6}_traffic_ok flags set from their listeners, and
for begindir entry connections we didn't care, but for directory
self-testing, we had a problem.
Fixes at least one more case of 7493; if there are more lingering
cases of 7493, this might fix them too.
Nick Mathewson [Fri, 16 Nov 2012 03:49:43 +0000 (22:49 -0500)]
Allow IPv4 traffic on default and old-style-config SocksPorts.
Looks like when i was writing the code to set the ipv4_traffic flag on
port_cfg_t, I missed some cases, such as the one where the port was
set from its default value.
Nick Mathewson [Thu, 15 Nov 2012 17:17:36 +0000 (12:17 -0500)]
Remove some XXXX commens in dns.c
Previously, I was freaking out about passing an unspec address to
dns_found_answer() on an error, since I was using the address type to
determine whether the error was an error on an ipv4 address lookup or
on an ipv6 address lookup. But now dns_found_answer() has a separate
orig_query_type argument to tell what kind of query it is, so there's
no need to freak out.
Nick Mathewson [Thu, 15 Nov 2012 03:06:13 +0000 (22:06 -0500)]
Make DNS resolve requests work for IPv6
* If there's an IPv4 and an IPv6 address, return both in the resolved
cell.
* Treat all resolve requests as permitting IPv6, since by the spec they're
allowed to, and by the code that won't break anything.
Nick Mathewson [Wed, 14 Nov 2012 15:14:23 +0000 (10:14 -0500)]
Repair DNS NEXIST hijacking workaround
The code previously detected wildcarding and replaced wildcarded
answers with DNS_STATUS_FAILED_PERMANENT. But that status variable
was no longer used! Remove the status variable, and instead change
the value of 'result' in evdns_callback.
Thank goodness for compiler warnings. In this case,
unused-but-set-variable.
Nick Mathewson [Mon, 5 Nov 2012 18:26:29 +0000 (13:26 -0500)]
Revise the DNS subsystem to handle IPv6 exits.
Now, every cached_resolve_t can remember an IPv4 result *and* an IPv6
result. As a light protection against timing-based distinguishers for
IPv6 users (and against complexity!), every forward request generates
an IPv4 *and* an IPv6 request, assuming that we're an IPv6 exit. Once
we have answers or errors for both, we act accordingly.
This patch additionally makes some useful refactorings in the dns.c
code, though there is quite a bit more of useful refactoring that could
be done.
Additionally, have a new interface for the argument passed to the
evdns_callback function. Previously, it was just the original address
we were resolving. But it turns out that, on error, evdns doesn't
tell you the type of the query, so on a failure we didn't know whether
IPv4 or IPv6 queries were failing.
The new convention is to have the first byte of that argument include
the query type. I've refactored the code a bit to make that simpler.
Nick Mathewson [Wed, 31 Oct 2012 22:27:48 +0000 (18:27 -0400)]
Get the client side of receiving an IPv6 address to work
This makes it so we can handle getting an IPv6 in the 3 different
formats we specified it for in RESOLVED cells,
END_STREAM_REASON_EXITPOLICY cells, and CONNECTED cells.
We don't cache IPv6 addresses yet, since proposal 205 isn't
implemented.
There's a refactored function for parsing connected cells; it has unit
tests.
Nick Mathewson [Sat, 27 Oct 2012 20:34:49 +0000 (16:34 -0400)]
Make DNS callback pass IPv6 answers to dns_answer_found
Also, count ipv6 timeouts vs others. If we have too many ipv6
requests time out, then we could be degrading performance because of a
broken DNS server that ignores AAAA requests. Other cases in which
we never learn an AAAA address aren't so bad, since they don't slow
A (ipv4) answers down very much.
Nick Mathewson [Thu, 25 Oct 2012 03:45:24 +0000 (23:45 -0400)]
Simplest version of server-side IPv6 support (no dns)
This is a relatively simple set of changes: we mostly need to
remove a few "but not for IPv6" changes. We also needed to tweak
the handling of DNS code to generate RESOLVED cells that could get
an IPv6 answer in return.
Nick Mathewson [Wed, 24 Oct 2012 16:33:18 +0000 (12:33 -0400)]
Add a new family-specific syntax for tor_addr_parse_mask_ports
By default, "*" means "All IPv4 addresses" with
tor_addr_parse_mask_ports, so I won't break anything. But if the new
EXTENDED_STAR flag is provided, then * means "any address", *4 means
"any IPv4 address" (that is, 0.0.0.0/0), and "*6" means "any IPv6
address" (that is, [::]/0).
This is going to let us have a syntax for specifying exit policies in
torrc that won't drive people mad.
Also, add a bunch of unit tests for tor_addr_parse_mask_ports to test
these new features, and to increase coverage.
Nick Mathewson [Sun, 28 Oct 2012 21:13:37 +0000 (17:13 -0400)]
Refactor client_dns_set_{reverse_,}addressmap() to take a circ
We'd like these functions to be circuit-relative so that we can
implement a per-circuit DNS cache and per-circuit DNS cache rules for
proposal 205 or its successors. I'm doing this now, as a part of the
IPv6 exits code, since there are about to be a few more instances
of code using this.