Nick Mathewson [Wed, 16 Apr 2014 19:17:23 +0000 (15:17 -0400)]
Use SCMP_CMP_MASKED_EQ to allow flags, not force them
Older versions of Libevent are happy to open SOCK_DGRAM sockets
non-cloexec and non-nonblocking, and then set those flags
afterwards. It's nice to be able to allow a flag to be on or off in
the sandbox without having to enumerate all its values.
Nick Mathewson [Wed, 16 Apr 2014 18:54:39 +0000 (14:54 -0400)]
Get Libevent's PRNG functioning under the linux sandbox
Libevent uses an arc4random implementation (I know, I know) to
generate DNS transaction IDs and capitalization. But it liked to
initialize it either with opening /dev/urandom (which won't work
under the sandbox if it doesn't use the right pointer), or with
sysctl({CTL_KERN,KERN_RANDOM,RANDOM_UUIC}). To make _that_ work, we
were permitting sysctl unconditionally. That's not such a great
idea.
Instead, we try to initialize the libevent PRNG _before_ installing
the sandbox, and make sysctl always fail with EPERM under the
sandbox.
Nick Mathewson [Wed, 16 Apr 2014 16:59:33 +0000 (12:59 -0400)]
Introduce arg-counting macros to wrap seccomp_rule_add()
The compiler doesn't warn about this code:
rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, SCMP_SYS(openat), 1,
SCMP_CMP(0, SCMP_CMP_EQ, AT_FDCWD),
SCMP_CMP(1, SCMP_CMP_EQ, param->value),
SCMP_CMP(2, SCMP_CMP_EQ, O_RDONLY|...));
but note that the arg_cnt argument above is only 1. This means that
only the first filter (argument 0 == AT_FDCWD) is actually checked!
This patch also fixes the above error in the openat() filter.
Earlier I fixed corresponding errors in filters for rename() and
mprotect().
Nick Mathewson [Fri, 11 Apr 2014 07:04:16 +0000 (03:04 -0400)]
Drop 'fr' parameter from sandbox code.
Appearently, the majority of the filenames we pass to
sandbox_cfg_allow() functions are "freeable right after". So, consider
_all_ of them safe-to-steal, and add a tor_strdup() in the few cases
that aren't.
Nick Mathewson [Fri, 28 Mar 2014 07:51:50 +0000 (03:51 -0400)]
Add 'rename' to the sandboxed syscalls
(If we don't restrict rename, there's not much point in restricting
open, since an attacker could always use rename to make us open
whatever they want.)
dana koch [Tue, 15 Apr 2014 12:20:34 +0000 (22:20 +1000)]
Uplift status.c unit test coverage with new test cases and macros.
A new set of unit test cases are provided, as well as introducing
an alternative paradigm and macros to support it. Primarily, each test
case is given its own namespace, in order to isolate tests from each
other. We do this by in the usual fashion, by appending module and
submodule names to our symbols. New macros assist by reducing friction
for this and other tasks, like overriding a function in the global
namespace with one in the current namespace, or declaring integer
variables to assist tracking how many times a mock has been called.
A set of tests for a small-scale module has been included in this
commit, in order to highlight how the paradigm can be used. This
suite gives 100% coverage to status.c in test execution.
Nick Mathewson [Mon, 14 Apr 2014 18:10:05 +0000 (14:10 -0400)]
New sort order for server choice of ciphersuites.
Back in 175b2678, we allowed servers to recognize clients who are
telling them the truth about their ciphersuites, and select the best
cipher from on that list. This implemented the server side of proposal
198.
In bugs 11492, 11498, and 11499, cypherpunks found a bunch of mistakes
and omissions and typos in the UNRESTRICTED_SERVER_CIPHER_LIST we had.
In #11513, I found a couple more.
Rather than try to hand-edit this list, I wrote a short python script
to generate our ciphersuite preferences from the openssl headers.
The new rules are:
* Require forward secrecy.
* Require RSA (since our servers only configure RSA keys)
* Require AES or 3DES. (This means, reject RC4, DES, SEED, CAMELLIA,
and NULL.)
* No export ciphersuites.
Then:
* Prefer AES to 3DES.
* If both suites have the same cipher, prefer ECDHE to DHE.
* If both suites have the same DHE group type, prefer GCM to CBC.
* If both suites have the same cipher mode, prefer SHA384 to SHA256
to SHA1.
* If both suites have the same digest, prefer AES256 to AES128.
Nick Mathewson [Thu, 10 Apr 2014 19:44:52 +0000 (15:44 -0400)]
Log a backtrace when the sandbox finds a failure
This involves some duplicate code between backtrace.c and sandbox.c,
but I don't see a way around it: calling more functions would mean
adding more steps to our call stack, and running clean_backtrace()
against the wrong point on the stack.
Nick Mathewson [Wed, 9 Apr 2014 00:34:23 +0000 (20:34 -0400)]
Start work on the changelog for 0.2.5.4-alpha
This commit does nothing other than pull the changes/* files into
ChangeLog, sorted by declared type. I haven't comined any entries or
vetted anything yet.
Matthew Finkel [Tue, 1 Apr 2014 21:30:20 +0000 (17:30 -0400)]
Check for new IP addr after circuit liveliness returns
When we successfully create a usable circuit after it previously
timed out for a certain amount of time, we should make sure that
our public IP address hasn't changed and update our descriptor.
Nick Mathewson [Tue, 8 Apr 2014 15:31:48 +0000 (11:31 -0400)]
Update ciphers.inc to match ff28
The major changes are to re-order some ciphers, to drop the ECDH suites
(note: *not* ECDHE: ECDHE is still there), to kill off some made-up
stuff (like the SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA suite), to drop
some of the DSS suites... *and* to enable the ECDHE+GCM ciphersuites.
This change is autogenerated by get_mozilla_ciphers.py from
Firefox 28 and OpenSSL 1.0.1g.
Nick Mathewson [Wed, 11 Dec 2013 19:45:48 +0000 (14:45 -0500)]
Fix undefined behavior with pointer addition in channeltls.c
In C, it's a bad idea to do this:
char *cp = array;
char *end = array + array_len;
/* .... */
if (cp + 3 >= end) { /* out of bounds */ }
because cp+3 might be more than one off the end of the array, and
you are only allowed to construct pointers to the array elements,
and to an element one past the end. Instead you have to say
if (cp - array + 3 >= array_len) { /* ... */ }
or something like that.
This patch fixes two of these: one in process_versions_cell
introduced in 0.2.0.10-alpha, and one in process_certs_cell
introduced in 0.2.3.6-alpha. These are both tracked under bug
10363. "bobnomnom" found and reported both. See also 10313.
In our code, this is likely to be a problem as we used it only if we
get a nasty allocator that makes allocations end close to (void*)-1.
But it's best not to have to worry about such things at all, so
let's just fix all of these we can find.
projects / thirdparty / tor.git / log
