1
0
mirror of https://git.tartarus.org/simon/putty.git synced 2025-01-10 18:07:59 +00:00
Commit Graph

601 Commits

Author SHA1 Message Date
Simon Tatham
cc4fbe33bc Prepare to have multiple X11 auth cookies valid at once.
Rather than the top-level component of X forwarding being an
X11Display structure which owns some auth data, it's now a collection
of X11FakeAuth structures, each of which owns a display. The idea is
that when we receive an X connection, we wait to see which of our
available auth cookies it matches, and then connect to whatever X
display that auth cookie identifies. At present the tree will only
have one thing in it; this is all groundwork for later changes.

[originally from svn r10079]
2013-11-17 14:05:10 +00:00
Simon Tatham
01085358e4 Decouple X socket opening from x11_init().
Now we wait to open the socket to the X server until we've seen the
authorisation data. This prepares us to do something else with the
channel if we see different auth data, which will come up in
connection sharing.

[originally from svn r10078]
2013-11-17 14:05:04 +00:00
Simon Tatham
b71b443c7c Add a missing null pointer check in s_write.
I don't know that this can ever be triggered in the current state of
the code, but when I start mucking around with SSH session closing in
the near future, it may be handy to have it.

[originally from svn r10076]
2013-11-17 14:04:56 +00:00
Simon Tatham
9cbcd17651 Refactor ssh.c's APIs to x11fwd.c and portfwd.c.
The most important change is that, where previously ssh.c held the
Socket pointer for each X11 and port forwarding, and the support
modules would find their internal state structure by calling
sk_get_private_ptr on that Socket, it's now the other way round. ssh.c
now directly holds the internal state structure pointer for each
forwarding, and when the support module needs the Socket it looks it
up in a field of that. This will come in handy when I decouple socket
creation from logical forwarding setup, so that X forwardings can
delay actually opening a connection to an X server until they look at
the authentication data and see which server it has to be.

However, while I'm here, I've also taken the opportunity to clean up a
few other points, notably error message handling, and also the fact
that the same kind of state structure was used for both
connection-type and listening-type port forwardings. Now there are
separate PortForwarding and PortListener structure types, which seems
far more sensible.

[originally from svn r10074]
2013-11-17 14:04:41 +00:00
Simon Tatham
518facfeca Complete rewrite of the packet log censoring code.
Because the upcoming connection sharing changes are going to involve
us emitting outgoing SSH packets into our log file that we didn't
construct ourselves, we can no longer rely on metadata inserted at
packet construction time to tell us which parts of which packets have
to be blanked or omitted in the SSH packet log. Instead, we now have
functions that deal with constructing the blanks array just before
passing all kinds of packet (both SSH-1 and SSH-2, incoming and
outgoing) to logging.c; the blanks/nblanks fields in struct Packet are
therefore no longer needed.

[originally from svn r10071]
2013-11-17 14:04:25 +00:00
Simon Tatham
9f5d51a4ac Clean up the 'data' vs 'body' pointers in struct Packet.
There's always been some confusion over exactly what it all means. I
haven't cleaned it up to the point of complete sensibleness, but I've
got it to a point where I can at least understand and document the
remaining non-sensibleness.

[originally from svn r10070]
2013-11-17 14:04:18 +00:00
Simon Tatham
0bc76b8252 Move SSH protocol enumerations out into ssh.h.
This permits packet type codes and other magic numbers to be accessed
from modules other than ssh.c.

[originally from svn r10064]
2013-11-17 14:03:29 +00:00
Simon Tatham
5ecb7d7f1d Clean up the semantics of the ssh_rportfwd structure.
It's now indexed by source hostname as well as source port (so that
separate requests for the server to listen on addr1:1234 and
addr2:1234 can be disambiguated), and also its destination host name
is dynamically allocated rather than a fixed-size buffer.

[originally from svn r10062]
2013-11-17 14:03:21 +00:00
Simon Tatham
043a762b5f Handle socket errors on half-open channels.
Anthony Ho reports that this can occur naturally in some situation
involving Windows 8 + IE 11 and dynamic port forwarding: apparently we
get through the SOCKS negotiation, send our CHANNEL_OPEN, and then
*immediately* suffer a local WSAECONNABORTED error before the server
has sent back its OPEN_CONFIRMATION or OPEN_FAILURE. In this situation
ssh2_channel_check_close was failing to notice that the channel didn't
yet have a valid server id, and sending out a CHANNEL_CLOSE anyway
containing 32 bits of uninitialised nonsense.

We now handle this by turning our half-open CHAN_SOCKDATA_DORMANT into
a half-open CHAN_ZOMBIE, which means in turn that our handler
functions for OPEN_CONFIRMATION and OPEN_FAILURE have to recognise and
handle that case, the former by immediately initiating channel closure
once we _do_ have the channel's server id to do it with.

[originally from svn r10039]
2013-09-08 13:20:49 +00:00
Simon Tatham
8e7b0d0e4b Pass an error message through to sshfwd_unclean_close.
We have access to one at every call site, so there's really no reason
not to send it through to ssh.c to be logged.

[originally from svn r10038]
2013-09-08 07:14:56 +00:00
Simon Tatham
7e515c4111 Fix free of an uninitialised pointer.
CHAN_AGENT channels need c->u.a.message to be either NULL or valid
dynamically allocated memory, because it'll be freed by
ssh_channel_destroy. This bug triggers if an agent forwarding channel
is opened and closed without having sent any queries.

[originally from svn r10032]
2013-08-26 11:55:56 +00:00
Simon Tatham
b8e668cd9b Sensibly enforce non-interactive rekeying.
We now only present the full set of host key algorithms we can handle
in the first key exchange. In subsequent rekeys, we present only the
host key algorithm that we agreed on the previous time, and then we
verify the host key by simply enforcing that it's exactly the same as
the one we saw at first and disconnecting rudely if it isn't.

[originally from svn r10027]
2013-08-18 06:48:20 +00:00
Simon Tatham
808df44e54 Add an assortment of missing consts I've just noticed.
[originally from svn r9972]
2013-07-27 18:35:48 +00:00
Simon Tatham
eaea69ef53 If the SSH server sends us CHANNEL_CLOSE for a channel on which we're
sitting on a pile of buffered data waiting for WINDOW_ADJUSTs, we
should throw away that buffered data, because the CHANNEL_CLOSE tells
us that we won't be receiving those WINDOW_ADJUSTs, and if we hang on
to the data and keep trying then it'll prevent ssh_channel_try_eof
from sending the CHANNEL_EOF which is a prerequisite of sending our
own CHANNEL_CLOSE.

[originally from svn r9953]
2013-07-21 10:12:58 +00:00
Simon Tatham
0d7f2fdabc In the various channel request mini-coroutines, replace
crWaitUntilV(pktin) with plain crReturnV, because those coroutines can
be called back either with a response packet from the channel request
_or_ with NULL by ssh_free meaning 'please just clean yourself up'.

[originally from svn r9927]
2013-07-14 17:08:35 +00:00
Simon Tatham
2f6d6a839d Move the calculation of the exchange hash to above the various
warnings about insecure crypto components. The latter may crReturn
(though not in any current implementation, I believe), which
invalidates pktin, which is used by the former.

[originally from svn r9921]
2013-07-14 10:46:27 +00:00
Simon Tatham
ea301bdd9b Fix another giant batch of resource leaks. (Mostly memory, but there's
one missing fclose too.)

[originally from svn r9919]
2013-07-14 10:46:07 +00:00
Simon Tatham
896bb7c74d Tighten up a lot of casts from unsigned to int which are read by one
of the GET_32BIT macros and then used as length fields. Missing bounds
checks against zero have been added, and also I've introduced a helper
function toint() which casts from unsigned to int in such a way as to
avoid C undefined behaviour, since I'm not sure I trust compilers any
more to do the obviously sensible thing.

[originally from svn r9918]
2013-07-14 10:45:54 +00:00
Simon Tatham
ac8baf4cac Move the SSH-1 servkey and hostkey variables into the coroutine state,
since there is a theoretical code path (via the crReturn loop after
asking an interactive question about a host key or crypto algorithm)
on which we can leave and return to do_ssh1_login between allocating
and freeing those keys.

(In practice it shouldn't come up anyway with any of the current
implementations of the interactive question functions, not to mention
the unlikelihood of anyone non-specialist still using SSH-1, but
better safe than sorry.)

[originally from svn r9895]
2013-07-07 14:34:37 +00:00
Simon Tatham
bbc9709b48 A collection of small bug fixes from Chris West, apparently spotted by
Coverity: assorted language-use goofs like freeing the wrong thing or
forgetting to initialise a string on all code paths.

[originally from svn r9889]
2013-07-01 17:56:33 +00:00
Ben Harris
8f3cc4a9bf Add support for HMAC-SHA-256 as an SSH-2 MAC algorithm ("hmac-sha2-256")
as specified in RFC 6668.  This is not so much because I think it's 
necessary, but because scrypt uses HMAC-SHA-256 and once we've got it we 
may as well use it.

Code very closely derived from the HMAC-SHA-1 code.

Tested against OpenSSH 5.9p1 Debian-5ubuntu1.

[originally from svn r9759]
2013-02-20 23:30:55 +00:00
Ben Harris
bc8f2193f6 Allow remote-to-local forwardings to use IPv6.
RFC 4245 section 7.1 specifies the meaning of the "address to bind"
parameter in a "tcpip-forward" request.  "0.0.0.0" and "127.0.0.1" are
specified to be all interfaces and the loopback interface respectively
in IPv4, while "" and "localhost" are the address-family-agnostic
equivalents.  Switch PuTTY to using the latter, since it doesn't seem
right to force IPv4.

There's an argument that PuTTY should provide a means of configuring the
address family used for remote forwardings like it does for local ones.

[originally from svn r9668]
2012-09-18 21:50:47 +00:00
Ben Harris
d5836982e2 Two related changes to timing code:
First, make absolute times unsigned.  This means that it's safe to 
depend on their overflow behaviour (which is undefined for signed 
integers).  This requires a little extra care in handling comparisons, 
but I think I've correctly adjusted them all.

Second, functions registered with schedule_timer() are guaranteed to be 
called with precisely the time that was returned by schedule_timer().  
Thus, it's only necessary to check these values for equality rather than 
doing risky range checks, so do that.

The timing code still does lots that's undefined, unnecessary, or just
wrong, but this is a good start.

[originally from svn r9667]
2012-09-18 21:42:48 +00:00
Ben Harris
8c1d1be956 Most of the code for "nc" mode duplicated that for opening a session or
a fowarded port.  Arrange that this code is shared instead.  The main
visible change is a slight change of log messages.

[originally from svn r9655]
2012-09-08 19:46:07 +00:00
Simon Tatham
14539a7719 Hiroshi Oota points out that PuTTY's agent forwarding sockets can get
confused if they receive a request followed by immediate EOF, since we
currently send outgoing EOF as soon as we see the incoming one - and
then, when the response comes back from the real SSH agent, we send it
along anyway as channel data in spite of having sent EOF.

To fix this, I introduce a new field for each agent channel which
counts the number of calls to ssh_agentf_callback that are currently
expected, and we don't send EOF on an agent channel until we've both
received EOF and that value drops to zero.

[originally from svn r9651]
2012-09-08 10:40:36 +00:00
Ben Harris
33c58dd91b Factor out some common code for constructing SSH2_CHANNEL_OPEN.
[originally from svn r9649]
2012-09-01 12:28:38 +00:00
Ben Harris
de6d59b500 struct winadj is unused now. G/c it.
[originally from svn r9648]
2012-09-01 12:10:27 +00:00
Ben Harris
98e562b7f6 All of the initial CHANNEL_REQUESTs are conditional on (ssh->mainchan &&
!ssh->ncmode), so bundle them up in a big block conditional on this rather
than checking it five times.

[originally from svn r9647]
2012-09-01 12:03:12 +00:00
Ben Harris
54da9ee07a do_ssh2_authconn() now installs the standard handlers for CHANNEL_SUCCESS
and CHANNEL_FAILURE as soon as it's opened a channel, so there's no need
for it to set them again later.

[originally from svn r9646]
2012-09-01 11:32:53 +00:00
Simon Tatham
b631c1e18e Rename the various ssh2_maybe_setup_* functions to ssh2_setup_*, and
move the primary conditions out of them into their callers. Fixes a
crash in 'plink -N', since those functions would be called with a NULL
channel parameter and immediately dereference it to try to get c->ssh.

[originally from svn r9644]
2012-08-30 18:44:35 +00:00
Ben Harris
e27ce2017e Change return type of do_ssh2_transport() to void.
Nothing pays attention to it any more, anyway.

[originally from svn r9635]
2012-08-27 22:02:17 +00:00
Ben Harris
3cc03d85e7 Make bombout() less of a macro and more of a function.
This gives GCC slightly fewer opportunities to gratuitously inflate
its output.

[originally from svn r9634]
2012-08-27 21:55:45 +00:00
Ben Harris
df83634e21 Fix a memory leak in parse_ttymodes() (found by Memcheck/Valgrind).
[originally from svn r9633]
2012-08-27 19:11:39 +00:00
Ben Harris
475507e978 Slightly simplify crFinishFree{,V}.
They're only likely to be useful for freeing a coroutine state
structure, in which case there's no need to reset the line number
(since all such coroutines keep their line number in the state
structure) and the state structure pointer is always called "s".

[originally from svn r9632]
2012-08-27 18:44:06 +00:00
Ben Harris
0768c8557d Don't close SSH-2 channels with outstanding channel requests on local error.
In sshfwd_unclean_close(), get ssh2_check_close() to handle sending
SSH_MSG_CHANNEL_CLOSE.  That way, it can hold off doing so until any
outstanding channel requests are processed.

Also add event log message for unclean channel closures.

[originally from svn r9631]
2012-08-27 17:37:44 +00:00
Simon Tatham
3fa95b2a7f It's not legal to free a coroutine's state structure before invoking
crFinish or crFinishV, since they will attempt to write to the
coroutine state variable contained in that structure. Introduced some
new all-in-one macros crFinishFree and crFinishFreeV, and used those
instead. Should fix today's report of a crash just after authentication.

[originally from svn r9630]
2012-08-27 14:34:41 +00:00
Ben Harris
3d466aec90 Better handling of outstanding CHANNEL_REQUESTS on channel destruction.
Part the first: make sure that all structures describing channel
requests are freed when the SSH connection is freed.  This involves
adding a means to ask a response handler to free any memory it holds.

Part the second: in ssh_channel_try_eof(), call
ssh2_channel_check_close() rather than emitting an SSH_MSG_CHANNEL_EOF
directly.  This avoids the possibility of closing the channel while a
CHANNEL_REQUEST is outstanding.

Also add some assertions that helped with tracking down the latter
problem.

[originally from svn r9623]
2012-08-25 21:06:48 +00:00
Ben Harris
4e623f5b23 Factor out common code to construct CHANNEL_REQUESTS.
This reduces code size a little and also makes it harder to
accidentally request a reply without putting in place a handler for
it or vice versa.

[originally from svn r9620]
2012-08-25 15:57:05 +00:00
Ben Harris
ab6d966f91 Simplify handling of responses to channel requests.
The various setup routines can only receive CHANNEL_SUCCESS or
CHANNEL_FAILURE, so there's no need for the to worry about receiving
anything else.  Strange packets will end up in do_ssh2_authconn
instead.

[originally from svn r9619]
2012-08-25 15:04:29 +00:00
Ben Harris
30e43ba2a3 Handle all replies to CHANNEL_REQUESTs through the per-channel queue.
Each of the minor start-of-session requests is now dealt with by its own 
little co-routine, while the shell/command is done in do_ssh2_authconn() 
itself.  This eliminates one more round-trip in session setup: PuTTY gets
all the way up to sending a shell request before worrying about any
replies.

[originally from svn r9616]
2012-08-25 13:39:32 +00:00
Ben Harris
57945a753f Generalise SSH_MSG_CHANNEL_{SUCCESS,FAILURE} handling.
Now each channel has a queue of arbitrary handlers for those messages, 
with anything that sends a CHANNEL_REQUEST with want_reply true pushing 
a new entry onto the queue, and a shared handler that dispatches 
responses appropriately.

Currently, this is only used for winadj@putty.projects.tartarus.org, but 
extending it to cover the initial requests as well shouldn't be too 
painful.

[originally from svn r9615]
2012-08-25 11:12:14 +00:00
Ben Harris
f071feb9a6 Fix recently-introduced memory leak in ssh2_msg_unexpected().
[originally from svn r9611]
2012-08-21 23:04:22 +00:00
Ben Harris
e148dd97e3 De-duplicate code in KEXINIT generation.
There's no need to have identical code generating server-to-client and
client-to-server versions of the cipher and MAC lists; a couple of
twice-around loops will do fine.

[originally from svn r9610]
2012-08-21 22:33:31 +00:00
Ben Harris
8e0ab8be59 Reworking of packet delivery to coroutines in SSH-2.
Before, NULL in the dispatch table meant "send to the appropriate one of 
do_ssh2_transport() and do_ssh2_authconn()".  Now those (via small 
shims) are specified directly in the dispatch table, so ssh2_protocol() 
is much simpler.

In the process, this has somewhat centralised the handling of gross 
server protocol violations.  PuTTY will now disconnect with a rude 
message when (e.g.) OpenSSH sends us an SSH_MSG_UNIMPLEMENTED when we 
try to KEXINIT during authentication.

[originally from svn r9609]
2012-08-21 22:04:56 +00:00
Ben Harris
4e5012aeda Fix an erroneous "case" fallthrough in ssh1_msg_channel_close, which was
causing assertion failures when closing X11 channels in SSH-1.  Also fix 
another pasto.

[originally from svn r9608]
2012-08-19 11:35:26 +00:00
Ben Harris
e570820c74 Tweak to SSH coroutine code: put line number in the coroutine state
structure, which is consistent with Simon's canonical version of the
macros.

[originally from svn r9607]
2012-08-18 09:30:01 +00:00
Ben Harris
37ea0f4541 Reduce the number of round-trips involved in opening an SSH-2 session
by sending most of the initial SSH_MSG_CHANNEL_REQUEST messages before
waiting for any replies.  The initial version of this code was a clever
thing with a two-pass loop, but that got hairy so I went for the simpler
approach of separating the request and reply code and having flags to
keep track of which requests have been sent.

[originally from svn r9599]
2012-08-02 22:18:18 +00:00
Simon Tatham
71f0c7546d Add a bug-compatibility flag to disable the
winadj@putty.projects.tartarus.org request. Not currently enabled
automatically, but should be usable as a manual workaround.

[originally from svn r9592]
2012-07-28 19:30:12 +00:00
Simon Tatham
aa5bae8916 Introduce a new utility function smemclr(), which memsets things to
zero but does it in such a way that over-clever compilers hopefully
won't helpfully optimise the call away if you do it just before
freeing something or letting it go out of scope. Use this for
(hopefully) every memset whose job is to destroy sensitive data that
might otherwise be left lying around in the process's memory.

[originally from svn r9586]
2012-07-22 19:51:50 +00:00
Simon Tatham
a46aac386b Add missing check for failure to agree a host key algorithm.
[originally from svn r9557]
2012-06-04 23:32:36 +00:00