Our public key functions assumed that they were always writing into a
large enough buffer. In one case, they weren't.
(Incorporates fixes from sebastian)
The C standard says that INT32_MAX is supposed to be a signed
integer. On platforms that have it, we get the correct
platform-defined value. Our own replacement, however, was
unsigned. That's going to cause a bug somewhere eventually.
C99 allows a syntax for structures whose last element is of
unspecified length:
struct s {
int elt1;
...
char last_element[];
};
Recent (last-5-years) autoconf versions provide an
AC_C_FLEXIBLE_ARRAY_MEMBER test that defines FLEXIBLE_ARRAY_MEMBER
to either no tokens (if you have c99 flexible array support) or to 1
(if you don't). At that point you just use offsetof
[STRUCT_OFFSET() for us] to see where last_element begins, and
allocate your structures like:
struct s {
int elt1;
...
char last_element[FLEXIBLE_ARRAY_MEMBER];
};
tor_malloc(STRUCT_OFFSET(struct s, last_element) +
n_elements*sizeof(char));
The advantages are:
1) It's easier to see which structures and elements are of
unspecified length.
2) The compiler and related checking tools can also see which
structures and elements are of unspecified length, in case they
wants to try weird bounds-checking tricks or something.
3) The compiler can warn us if we do something dumb, like try
to stack-allocate a flexible-length structure.
On Windows, we never use pthreads, since it doesn't usually exist,
and when it does it tends to be a little weirdly-behaved. But some
mingw installations have a pthreads installed, so autoconf detects
pthread.h and tells us about it. This would make us include
pthread.h, which could make for trouble when the iffy pthread.h
tried to include config.h.
This patch changes compat.h so that we never include pthread.h on
Windows. Fixes bug 2313; bugfix on 0.1.0.1-rc.
Libevent 2.0 has a "changelist" feature that avoids making redundant
syscalls if we wind up doing a lot of event_add/event_del operations
on the same fd in a row. Unfortunately, due to a weird design
choice in Linux, it doesn't work right with epoll when multiple fds
refer to the same socket (e.g., one is a dup() of the other). We
don't dup() anything we give to Libevent, though, so it is safe for
us to explicitly turn this feature on.
It's all too easy in C to convert an unsigned value to a signed one,
which will (on all modern computers) give you a huge signed value. If
you have a size_t value of size greater than SSIZE_T_MAX, that is way
likelier to be an underflow than it is to be an actual request for
more than 2gb of memory in one go. (There's nothing in Tor that
should be trying to allocate >2gb chunks.)
Doing so could make Libevent call Libevent from inside a Libevent
logging call, which is a recipe for reentrant confusion and
hard-to-debug crashes. This would especially hurt if Libevent
debug-level logging is enabled AND the user has a controller
watching for low-severity log messages.
Fix bug 2190; fix on 0.1.0.2-rc.
Doing so could make Libevent call Libevent from inside a Libevent
logging call, which is a recipe for reentrant confusion and
hard-to-debug crashes. This would especially hurt if Libevent
debug-level logging is enabled AND the user has a controller
watching for low-severity log messages.
Fix bug 2190; fix on 0.1.0.2-rc.
Having very long single lines with lots and lots of things in them
tends to make files hard to diff and hard to merge. Since our tools
are one-line-at-a-time, we should try to construct lists that way too,
within reason.
This incidentally turned up a few headers in configure.in that we were
for some reason searching for twice.
We need filtering bufferevent_openssl so that we can wrap around
IOCP bufferevents on Windows. This patch adds a temporary option to
turn on filtering mode, so that we can test it out on non-IOCP
systems to make sure it hasn't got any surprising bugs.
It also fixes some allocation/teardown errors in using
bufferevent_openssl as a filter.
In a2bb0bf we started using a separate client identity key. When we are
in "public server mode" (that means not a bridge) we will use the same
key. Reusing the key without doing the proper refcounting leads to a
segfault on cleanup during shutdown. Fix that.
Also introduce an assert that triggers if our refcount falls below 0.
That should never happen.
The old comment was from before I tried a huge pile of crazy stuff to
make the inner loop faster. Short answer: GCC already knows how to
unroll loops pretty well. Other short answer: we should have made the
relay payload size an even multiple of 4, 8, or ideally 16.
The short version is, "where we want to do it, we have nothing real to
chose from and we can't do it easily. Where it's easy to do, we have
no reason to do it yet."
First start of a fix for bug2001, but my test network still isn't
working: the client and the server send each other VERSIONS cells,
but never notice that they got them.
* Make tor_tls_context_new internal to tortls.c, and return the new
tor_tls_context_t from it.
* Add a public tor_tls_context_init wrapper function to replace it.
- Responsibility of clearing hex_errno is no longer with caller
- More conservative bounds checking
- Length requirement of hex_errno documented
- Output format documented
Some of these functions only work for routerinfo-based nodes, and as
such are only usable for advisory purposes. Fortunately, our uses
of them are compatible with this limitation.
The node_t type is meant to serve two key functions:
1) Abstracting difference between routerinfo_t and microdesc_t
so that clients can use microdesc_t instead of routerinfo_t.
2) Being a central place to hold mutable state about nodes
formerly held in routerstatus_t and routerinfo_t.
This patch implements a nodelist type that holds a node for every
router that we would consider using.
This is needed for IOCP, since telling the IOCP backend about all
your CPUs is a good idea. It'll also come in handy with asn's
multithreaded crypto stuff, and for people who run servers without
reading the manual.
This requires the latest Git version of Libevent as of 24 March 2010.
In the future, we'll just say it requires Libevent 2.0.5-alpha or
later.
Since Libevent doesn't yet support hierarchical rate limit groups,
there isn't yet support for tracking relayed-bytes separately when
using the bufferevent system. If a future version does add support
for hierarchical buckets, we can add that back in.
This function uses GetSystemDirectory() to make sure we load the version
of the library from c:\windows\system32 (or local equivalent) rather than
whatever version lives in the cwd.
This should keep WinCE working (unicode always-on) and get Win98
working again (unicode never-on).
There are two places where we explicitly use ASCII-only APIs, still:
in ntmain.c and in the unit tests.
This patch also fixes a bug in windoes tor_listdir that would cause
the first file to be listed an arbitrary number of times that was
also introduced with WinCE support.
Should fix bug 1797.
This should make us conflict less with system files named "log.h".
Yes, we shouldn't have been conflicting with those anyway, but some
people's compilers act very oddly.
The actual change was done with one "git mv", by editing
Makefile.am, and running
find . -name '*.[ch]' | xargs perl -i -pe 'if (/^#include.*\Wlog.h/) {s/log.h/torlog.h/; }'
These timers behave better with non-monotonic clocks than our old
ones, and also try harder to make once-per-second events get called
one second apart, rather than one-plus-epsilon seconds apart.
This fixes bug 943 for everybody using Libevent 2.0 or later.
From the code:
zlib 1.2.4 and 1.2.5 do some "clever" things with macros. Instead of
saying "(defined(FOO) ? FOO : 0)" they like to say "FOO-0", on the theory
that nobody will care if the compile outputs a no-such-identifier warning.
Sorry, but we like -Werror over here, so I guess we need to define these.
I hope that zlib 1.2.6 doesn't break these too.
Possible fix for bug 1526.
This should never happen unless openssl is buggy or some of our
assumptions are deeply wrong, but one of those might have been the
cause of the not-yet-reproducible bug 1209. If it ever happens again,
let's get some info we can use.
Having ~/.tor expand into /.tor is, after all, almost certainly not
what the user wanted, and it deserves a warning message.
Also, convert a guess-and-malloc-and-sprintf triple into an asprintf.
Most of the changes here are switches to use APIs available on Windows
CE. The most pervasive change is that Windows CE only provides the
wide-character ("FooW") variants of most of the windows function, and
doesn't support the older ASCII verions at all.
This patch will require use of the wcecompat library to get working
versions of the posix-style fd-based file IO functions.
[commit message by nickm]
1) mingw doesn't have _vscprintf(); mingw instead has a working snprintf.
2) windows compilers that _do_ have a working _vscprintf spell it so; they do
not spell it _vcsprintf().
Our code assumed that any version of OpenSSL before 0.9.8l could not
possibly require SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION. This is
so... except that many vendors have backported the flag from later
versions of openssl when they backported the RFC5476 renegotiation
feature.
The new behavior is particularly annoying to detect. Previously,
leaving SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION unset meant that
clients would fail to renegotiate. People noticed that one fast!
Now, OpenSSL's RFC5476 support means that clients will happily talk to
any servers there are, but servers won't accept renegotiation requests
from unpatched clients unless SSL_OP_ALLOW_etc is set. More fun:
servers send back a "no renegotiation for you!" error, which unpatched
clients respond to by stalling, and generally producing no useful
error message.
This might not be _the_ cause of bug 1346, but it is quite likely _a_
cause for bug 1346.
We used to only zero the first ptrsize bytes of the cipher. Since
cipher is large enough, we didn't zero too many bytes. Discovered
and fixed by ekir. Fixes bug 1254.
For my 64-bit Linux system running with GCC 4.4.3-fc12-whatever, you
can't do 'printf("%lld", (int64_t)x);' Instead you need to tell the
compiler 'printf("%lld", (long long int)x);' or else it doesn't
believe the types match. This is why we added U64_PRINTF_ARG; it
looks like we needed an I64_PRINTF_ARG too.
asprintf() is a GNU extension that some BSDs have picked up: it does a printf
into a newly allocated chunk of RAM.
Our tor_asprintf() differs from standard asprintf() in that:
- Like our other malloc functions, it asserts on OOM.
- It works on windows.
- It always sets its return-field.
On Windows, we don't have a notion of ~ meaning "our homedir", so we
were deliberately using an #ifdef to avoid calling expand_filename()
in multiple places. This is silly: The right place to turn a function
into a no-op on a single platform is in the function itself, not in
every single call-site.
We used to only zero the first ptrsize bytes of the cipher. Since
cipher is large enough, we didn't zero too many bytes. Discovered
and fixed by ekir. Fixes bug 1254.
We need to use evdns_add_server_port_with_base() when configuring
our DNS listener, because libevent segfaults otherwise. Add a macro
in compat_libevent.h to pick the correct implementation depending
on the libevent version.
Fixes bug 1143, found by SwissTorExit
This time, set the SSL3_FLAGS_ALLOW_UNSAFE_RENEGOTIATION flag on every
version before OpenSSL 0.9.8l. I can confirm that the option value (0x0010)
wasn't reused until OpenSSL 1.0.0beta3.
The src and dest of a memcpy() call aren't supposed to overlap,
but we were sometimes calling tor_addr_copy() as a no-op.
Also, tor_addr_assign was a redundant copy of tor_addr_copy(); this patch
removes it.
In brief: you mustn't use the SSL3_FLAG solution with anything but 0.9.8l,
and you mustn't use the SSL_OP solution with anything before 0.9.8m, and
you get in _real_ trouble if you try to set the flag in 1.0.0beta, since
they use it for something different.
For the ugly version, see my long comment in tortls.c
We need to do this because Apple doesn't update its dev-tools headers
when it updates its libraries in a security patch. On the bright
side, this might get us out of shipping a statically linked OpenSSL on
OSX.
May fix bug 1225.
[backported]
We need to do this because Apple doesn't update its dev-tools headers
when it updates its libraries in a security patch. On the bright
side, this might get us out of shipping a statically linked OpenSSL on
OSX.
May fix bug 1225.
We were checking for msg==NULL, but not lib or proc. This case can
only occur if we have an error whose string we somehow haven't loaded,
but it's worth coding defensively here.
Spotted by rieo on IRC.
We do this in too many places throughout the code; it's time to start
clamping down.
Also, refactor Karsten's patch to use strchr-then-strndup, rather than
malloc-then-strlcpy-then-strchr-then-clear.
This changes the pqueue API by requiring an additional int in every
structure that we store in a pqueue to hold the index of that structure
within the heap.
Some *_free functions threw asserts when passed NULL. Now all of them
accept NULL as input and perform no action when called that way.
This gains us consistence for our free functions, and allows some
code simplifications where an explicit null check is no longer necessary.
It turns out that OpenSSL 0.9.8m is likely to take a completely
different approach for reenabling renegotiation than OpenSSL 0.9.8l
did, so we need to work with both. :p Fixes bug 1158.
(patch by coderman; commit message by nickm)
On this OSX version, there is a stub mlockall() function
that doesn't work, *and* the declaration for it is hidden by
an '#ifdef _P1003_1B_VISIBLE'. This would make autoconf
successfully find the function, but our code fail to build
when no declaration was found.
This patch adds an additional test for the declaration.
This fixes bug 1147:
bionic doesn't have an actual implementation of mlockall();
mlockall() is merely in the headers but not actually in the library.
This prevents Tor compilation with the bionic libc for Android handsets.
To fix a major security problem related to incorrect use of
SSL/TLS renegotiation, OpenSSL has turned off renegotiation by
default. We are not affected by this security problem, however,
since we do renegotiation right. (Specifically, we never treat a
renegotiated credential as authenticating previous communication.)
Nevertheless, OpenSSL's new behavior requires us to explicitly
turn renegotiation back on in order to get our protocol working
again.
Amusingly, this is not so simple as "set the flag when you create
the SSL object" , since calling connect or accept seems to clear
the flags.
For belt-and-suspenders purposes, we clear the flag once the Tor
handshake is done. There's no way to exploit a second handshake
either, but we might as well not allow it.
This commit implements a new config option: 'DisableAllSwap'
This option probably only works properly when Tor is started as root.
We added two new functions: tor_mlockall() and tor_set_max_memlock().
tor_mlockall() attempts to mlock() all current and all future memory pages.
For tor_mlockall() to work properly we set the process rlimits for memory to
RLIM_INFINITY (and beyond) inside of tor_set_max_memlock().
We behave differently from mlockall() by only allowing tor_mlockall() to be
called one single time. All other calls will result in a return code of 1.
It is not possible to change DisableAllSwap while running.
A sample configuration item was added to the torrc.complete.in config file.
A new item in the man page for DisableAllSwap was added.
Thanks to Moxie Marlinspike and Chris Palmer for their feedback on this patch.
Please note that we make no guarantees about the quality of your OS and its
mlock/mlockall implementation. It is possible that this will do nothing at all.
It is also possible that you can ulimit the mlock properties of a given user
such that root is not required. This has not been extensively tested and is
unsupported. I have included some comments for possible ways we can handle
this on win32.
In 5e4d53d535 we made it so that
crypto_cipher_set_key cannot fail. The call will now
always succeed, to returning a boolean for success/failure makes
no sense.
In C, the code "char x[10]; if (x) {...}" always takes the true branch of
the if statement. Coverity notices this now.
In some cases, we were testing arrays to make sure that an operation
we wanted to do would suceed. Those cases are now always-true.
In some cases, we were testing arrays to see if something was _set_.
Those caes are now tests for strlen(s), or tests for
!tor_mem_is_zero(d,len).
See task 1114. The most plausible explanation for someone sending us weak
DH keys is that they experiment with their Tor code or implement a new Tor
client. Usually, we don't care about such events, especially not on warn
level. If we really care about someone not following the Tor protocol, we
can set ProtocolWarnings to 1.
This patch introduces a new type called document_signature_t to represent the
signature of a consensus document. Now, each consensus document can have up
to one document signature per voter per digest algorithm. Also, each
detached-signatures document can have up to one signature per <voter,
algorithm, flavor>.
Apparently the Android developers dumped OpenSSL's support for hardware
acceleration in order to save some memory, so you can't build programs using
engines on Android.
[Patch revised by nickm]
This shouldn't be necessary, but apparently the Android cross-compiler
doesn't respect -I as well as it should. (-I is supposed to add to the
*front* of the search path. Android's gcc wrapper apparently likes to add to
the end. This is broken, but we need to work around it.)
The big change is to add a function to display the current SSL handshake
state, and to log it everywhere reasonable. (A failure in
SSL23_ST_CR_SRVR_HELLO_A is different from one in
SSL3_ST_CR_SESSION_TICKET_A.)
This patch also adds a new log domain for OR handshaking, so you can pull out
all the handshake log messages without having to run at debug for everything.
For example, you'd just say "log notice-err [handshake]debug-err file
tor.log".
"Tinytest" is a minimalist C unit testing framework I wrote for
Libevent. It supports some generally useful features, like being able
to run separate unit tests in their own processes.
I tried to do the refactoring to change test.c as little as possible.
Thus, we mostly don't call the tinytest macros directly. Instead, the
test.h header is now a wrapper on tinytest.h to make our existing
test_foo() macros work.
The next step(s) here will be:
- To break test.c into separate files, each with its own test group.
- To look into which things we can test
- To refactor the more fiddly tests to use the tinytest macros
directly and/or run forked.
- To see about writing unit tests for things we couldn't previously
test without forking.
