storing a SHA-1 hash of the client and server version strings, store the
strings themselves so we can feed them through the appropriate hash when
we know what it is.
[originally from svn r6241]
processed and incoming data being processed out of order, which I suspect is
the cause of `ssh1-fwd-trouble' as noted by Gevan Dutton. I'm not able to
test the failure case, but it doesn't seem to have obviously broken anything
in the cases I have tested, anyway.
[originally from svn r6221]
marks a version string. It's a bit vague about the definition of a line,
but I think it's reasonable to assume that they'll end with LF. Change
do_ssh_init() to ignore "SSH-" anywhere else. This makes the existing state
machine overkill, so replace it with something a little more readable.
[originally from svn r6138]
do_ssh2_transport() was returning the wrong value for rekeys after the first.
This apparent error was introduced in r4901, but we can't see any reason for
the change to have been made. If it turns out to be a mistake to revert it,
I'm sure we'll find out.
Here for posterity is Simon's analysis:
| A lot of the return values from do_ssh2_transport appear to be vestigial: it
| used to be that a zero return from do_ssh2_transport meant it had handled the
| packet internally, and a 1 return meant the packet wasn't a transport-layer
| one and needed to pass on to do_ssh2_authconn. Since r4901, however, the
| layer discrimination is done based on the message type ranges, and the only
| remaining dependency on the return value from do_ssh2_transport is a special
| case in ssh2_protocol which detects the first 1 return and makes the
| initialisation call to do_ssh2_authconn.
|
| Therefore, the gratuitous 1 return on every key exchange as a result of the
| confusing if statement is simply ignored in ssh2_protocol (because
| ssh->protocol_initial_phase_done is already TRUE). So the remaining question
| was, why does the _lack_ of that 1 return not cause a problem, if the if's
| sense is indeed reversed?
|
| The answer is that 1 is still returned, just not by the crReturn inside the
| if statement. It's returned by the next crReturn, just after
| wait_for_rekey(). Which suggests that in fact, the if statement has the
| correct sense, but the crReturn inside it has the wrong value - it should be
| returning _zero_, to indicate that every NEWKEYS after the first one is
| uninteresting to the authconn code, and on the very first run through that
| doesn't happen and the NEWKEYS gets all the way to the crReturn(1) later on.
[originally from svn r5986]
[r4901 == a4ba026838]
enforce the following:
* Packet must have at least one byte of payload and four bytes of padding.
* Total packet length must not exceed 35000 bytes compressed.
* Total packet length including length field must be a multiple of cipher
block size (or eight bytes).
The feebleness of our old checks was noticed by Ben Rudiak-Gould.
[originally from svn r5981]
and add the ability to treat a local disconnection as "unclean" -- notably, if
we can't agree any authentication methods to even try; someone was complaining
that the PuTTY window by default just disappears for no apparent reason in this
circumstance.
Also, use appropriate disconnect codes for those SSH2_MSG_DISCONNECT messages
that we do send.
I don't think I've seriously broken any user-visible behaviour, but the way
that connection-close distinctions are transmitted to the front-end is shaky
(or so it seems to me), so there may be non-ideal changes on some platforms.
[originally from svn r5824]
hopefully solve `drop-banner'. I haven't been able to test the failure case,
but the behaviour with OpenSSH appears no worse.
[originally from svn r5772]
[this svn revision also touched putty-wishlist]
there are servers which could in principle operate in this mode, although I
don't know if any do in practice. (Hence, I haven't been able to test it.)
[originally from svn r5748]
[this svn revision also touched putty-wishlist]
server, which led to stalemate if the server did the same. PuTTY now sends
KEXINIT proactively as soon as it's worked out that it's talking SSH-2.
[originally from svn r5685]
default preferred cipher), add code to inject SSH_MSG_IGNOREs to randomise
the IV when using CBC-mode ciphers. Each cipher has a flag to indicate
whether it needs this workaround, and the SSH packet output maze has gained
some extra complexity to implement it.
[originally from svn r5659]
Unix Plink sends everything sensible it can find, and it's fully configurable
from the GUI.
I'm not entirely sure about the precise set of modes that Unix Plink should
look at; informed tweaks are welcome.
Also the Mac bits are guesses (but trivial).
[originally from svn r5653]
[this svn revision also touched putty-wishlist]
end, after the REQUIRED "hmac-sha1".) This has been present since SSH-2
support was introduced (r569).
[originally from svn r5643]
[r569 == 35205e5cb7]
I've added this to support `terminal-modes', but since this unifies some
SSH-1 and SSH-2 packet construction code, it saves a few hundred bytes.
Bonus.
[originally from svn r5642]
comp.security.ssh contains a Dr Watson log which looks to me as if
`unclean-close-crash' occurred due to a rekey timer going off after
the session had closed. Hence, ssh2_timer() now avoids doing
anything if the session is already closed, and also ssh_do_close()
proactively calls expire_timer_context(). Between those I think they
ought to solve the problem.
[originally from svn r5564]
ssh2_try_send() to no longer be run after receiving WINDOW_ADJUSTs.
I believe this is likely to have been the cause of recent PSCP
hanging issues.
[originally from svn r5517]
[r4909 == 02b0474f57]
discussed. Use Barrett and Silverman's convention of "SSH-1" for SSH protocol
version 1 and "SSH-2" for protocol 2 ("SSH1"/"SSH2" refer to ssh.com
implementations in this scheme). <http://www.snailbook.com/terms.html>
[originally from svn r5480]
prompts, to make it more obvious if a server is attempting to spoof a local
passphrase prompt.
I believe an alert user could have spotted this in all cases in SSH-2,
although perhaps not in SSH-1. (But they'd have to have enabled
TIS/CryptoCard.)
[originally from svn r5450]
Port forwardings are set up before initialising the last few details
of the main shell session, so ssh->state can reasonably hold values
other than SSH_STATE_SESSION and SSH_STATE_CLOSED during calls to
sshfwd_*.
[originally from svn r5446]
connection_fatal(), since the latter is entitled to destroy the
backend so `ssh' may no longer be valid once it returns.
For the Unix port, switch exit(0) to gtk_main_quit() in
notify_remote_exit(), so that we don't exit before the subsequent
connection_fatal()!
[originally from svn r5445]
cfg.remote_cmd is to be used, rather than actually pointing at
cfg.remote_cmd. This change restores the ability to structure-copy
Configs without breaking them. (Though of course this is only a
temporary solution: really what wants doing is to fix
`config-struct'.)
[originally from svn r5335]
now returns an integer: 0 means cancel the SSH connection and 1
means continue with it. Additionally, they can return -1, which
means `front end has set an asynchronous alert box in motion, please
wait to be called back with the result', and each one is passed a
callback function pointer and context for this purpose.
I have not yet done the same to askappend() yet, because it will
take a certain amount of reorganisation of logging.c.
Importantly, this checkin means the host key dialog box now works on
OS X.
[originally from svn r5330]
changing its mouse pointer. Currently this is only used in the (slightly-
arbitrarily-defined) "heavy" bits of SSH-2 key exchange. We override pointer
hiding while PuTTY is busy, but preserve pointer-hiding state.
Not yet implemented on the Mac.
Also switch to frobbing window-class cursor in Windows rather than relying on
SetCursor().
[originally from svn r5303]
for which we don't yet have a remote number, and instead add a flag to indicate
this fact. Fixes bug ssh-remoteid-minusone.
[originally from svn r5171]
tested since none of the common key-exchange protocols starts with a packet
from the server, so I don't have a server that implements this.
[originally from svn r5162]
only send it when it will significantly increase the server's idea of our
window. This avoids the slew of one-byte WINDOW_ADJUSTs that an interactive
shell typically generates.
[originally from svn r5121]
to see the server slam the TCP connection shut (i.e. almost never,
unless it's just sent us an SSH_MSG_DISCONNECT), and treat an
unexpected closure as a non-clean session termination. Previously
any server-initiated connection closure was being treated as a clean
exit, which was a hangover from the good old Telnet-only days.
[originally from svn r5098]
[this svn revision also touched putty-wishlist]
deal with rekeys at all: they totally ignore mid-session KEXINIT
sent by the client. Hence, a new bug entry so we don't try it.
[originally from svn r5092]
exchange. Without doing this, after we have done one specific-group
DH exchange (group1 or group14), ssh2_pkt_type _always_ translates
30 and 31 as KEXDH_INIT and KEXDH_REPLY, making a subsequent
group-exchange kex look rather strange in an SSH packet log.
[originally from svn r5081]
INFO_REQUESTs, and for some reason Debian OpenSSH is sending INFO_REQUESTs
containing no prompts after a normal password authentication, so this
should fix Shai's problem.
[originally from svn r5078]
[r5068 == 297ee2573e]
[this svn revision also touched putty-wishlist]
SSH connection when we're in the middle of asking the user a
dialog-box-type question. Fixes `unix-kex-packet', which has just
bitten me when connecting to one of the work Suns.
[originally from svn r5071]
[this svn revision also touched putty-wishlist]
long as the server offers it, rather than only once, unless the server responds
to our initial USERAUTH_REQUEST("keyboard-interactive") with FAILURE, in which
case we give up on it entirely.
[originally from svn r5068]
[this svn revision also touched putty-wishlist]
mid-session in SSH2: this forces an immediate rekey to activate the
new settings. I'm not sure exactly what this will be useful for
(except possibly it might make comparative performance testing
easier?), but it has wonderful James Bond value for being able to
switch to a more secure cipher before doing anything sensitive :-)
If, that is, you weren't using the most secure one to begin with...
[originally from svn r5051]
to be destroying old ones _before_ creating new ones, so that we can
reuse a port for a new purpose without colliding with ourselves.
Also fixed port forwarding, which my IPv6 checkin had completely
funted :-)
[originally from svn r5049]
of polishing to bring them to what I think should in principle be
release quality. Unlike the unfix.org patches themselves, this
checkin enables IPv6 by default; if you want to leave it out, you
have to build with COMPAT=-DNO_IPV6.
I have tested that this compiles on Visual C 7 (so the nightlies
_should_ acquire IPv6 support without missing a beat), but since I
don't have IPv6 set up myself I haven't actually tested that it
_works_. It still seems to make correct IPv4 connections, but that's
all I've been able to verify for myself. Further testing is needed.
[originally from svn r5047]
[this svn revision also touched putty-wishlist]
mid-session if we are not using SSHv1. I've done this by introducing
a generic `cfg_info' function which every back end can use to
communicate an int's worth of data to setup_config_box; in SSH
that's the protocol version in use, and in everything else it's
currently zero.
[originally from svn r5040]
[r5031 == d77102a8d5]
IPv6-unrelated changes, which convert ints into unsigned in a few
key places in ssh.c. Looks harmless at worst, possibly terribly
useful, so I think we'll have these no matter what the real IPv6
stuff is up to!
[originally from svn r5038]
bit is working out when to reschedule the next rekey for when the
timeout or data limit changes; sometimes it will be _right now_
because we're already over the new limit.
Still to do: the Kex panel should not appear in mid-session if we
are using SSHv1.
[originally from svn r5031]
Change Settings, the port forwarding setup function is run again,
and tags all existing port forwardings as `do not keep'. Then it
iterates through the config in the normal way; when it encounters a
port forwarding which is already in the tree, it tags it `keep'
rather than setting it up from scratch. Finally, it goes through the
tree and removes any that haven't been labelled `keep'. Hence,
editing the list of forwardings in Change Settings has the effect of
cancelling any forwardings you remove, and adding any new ones.
The SSH panel now appears in the reconfig box, and is empty apart
from a message explaining that it has to be there for subpanels of
it to exist. Better wording for this message would be welcome.
[originally from svn r5030]
routine which is common between SSH1 and SSH2. Since this routine is
not part of the coroutine system, this means it can't sit and wait
to get its various success/failure responses back. Hence, I've
introduced a system of queued packet handlers, each of which waits
for exactly one of a pair of messages (SSH1_SMSG_{SUCCESS,FAILURE}
or SSH2_MSG_REQUEST_{SUCCESS,FAILURE}), handles it when it arrives,
and automatically de-registers itself. Hence the port-forwarding
setup code can be called once, and then subsequent packets related
to it will automatically be handled as they arrive.
The real purpose of all this is that the infrastructure is now there
for me to arrange mid-session configurability of port forwarding.
However, a side benefit is that fewer round trips are involved in
session startup. I'd quite like to move more of the connection setup
(X forwarding, agent forwarding, pty allocation etc) to using the
new queued handler mechanism for this reason.
[originally from svn r5029]
(which will gain more content anon).
Retire BUG_SSH2_DH_GEX and add a backwards-compatibility wart, since we never
did find a way of automatically detecting this alleged server bug, and in any
case there was only ever one report (<3D91F3B5.7030309@inwind.it>, FWIW).
Also generalise askcipher() to a new askalg() (thus touching all the
front-ends).
I've made some attempt to document what SSH key exchange is and why you care,
but it could use some review for clarity (and outright lies).
[originally from svn r5022]
should stop ssh_do_close() accessing freed ssh->channels when invoked later
from ssh_free(). Spotted by Fred Sauer.
(Perhaps this is the cause of the crashes people have been reporting on
abnormal closures such as `Software caused connection abort'? I've not been
able to test this.)
[originally from svn r4946]
timing.c, and hence takes its own responsibility for calling
noise_regular() at regular intervals. Again, this means it will be
called consistently in _all_ the SSH-speaking tools, not just those
in which I remembered to call it!
[originally from svn r4913]
SSH2, is now handled by the packet dispatch table. Dispatch table
entries are enabled as soon as possible, so that if anyone tries to
(for example) start using a forwarded port before the main shell
session setup has finished, things should work sensibly.
The SSH code is now a hybrid of coroutine-based sequential logic and
table-driven event dispatch, each where it makes the most sense. I'm
rather pleased with it.
Should fix: ext-data-at-start, portfwd-at-start.
[originally from svn r4909]
[this svn revision also touched putty-wishlist]
data transfer in either direction (whichever comes first), or at
explicit client request (nice idea Jacob). Have tested by lowering
the limits, and it all seems solid enough; in particular, this has
also allowed me to test the behaviour when connection-level data is
received during rekey, and that looks fine too (at least it does
_now_ :-).
[originally from svn r4908]
[this svn revision also touched putty-wishlist]
which pretty much any module can call to request a call-back in the
future. So terminal.c can do its own handling of blinking, visual
bells and deferred screen updates, without having to rely on
term_update() being called 50 times a second (fixes: pterm-timer);
and ssh.c and telnet.c both invoke a new module pinger.c which takes
care of sending keepalives, so they get sent uniformly in all front
ends (fixes: plink-keepalives, unix-keepalives).
[originally from svn r4906]
[this svn revision also touched putty-wishlist]
ssh1_protocol() and ssh2_protocol() are now high-level functions
which see _every_ SSH packet and decide which lower-level function
to pass it to. Also, they each support a dispatch table of simple
handler functions for message types which can arrive at any time.
Results are:
- ignore, debug and disconnect messages are now handled by the
dispatch table rather than being warts in the rdpkt functions
- SSH2_MSG_WINDOW_ADJUST is handled by the dispatch table, which
means that do_ssh2_authconn doesn't have to explicitly
special-case it absolutely every time it waits for a response to
its latest channel request
- the top-level SSH2 protocol function chooses whether messages get
funnelled to the transport layer or the auth/conn layer based on
the message number ranges defined in the SSH architecture draft -
so things that should go to auth/conn go there even in the middle
of a rekey (although a special case is that nothing goes to
auth/conn until initial kex has finished). This should fix the
other half of ssh2-kex-data.
[originally from svn r4901]
can keep several of them in parallel. In particular, this allows us
to queue outgoing packets during repeat key exchange, to be actually
sent after the rekey completes.
(This doesn't fully fix ssh2-kex-data; also required is the ability
to handle _incoming_ connection-layer packets during rekey without
exploding.)
[originally from svn r4899]
structure have been retired. Now all Packet structures are
dynamically allocated. Each rdpkt function allocates one, and it's
freed after being used; and the packet construction functions
allocate them too, and they're freed by the send functions.
`pktin' and `pktout' were ugly. They were _morally_ still global
variables; even though they were replicated per SSH session to
comply with the Mac no-globals requirement, they weren't really in
the _spirit_ of `dynamically allocate your data'.
As a side effect of this change, the `pktout_blanks' and
`pktout_nblanks' fields in the Ssh structure have been moved into
the Packet structure.
[originally from svn r4898]
prompt for keyboard-interactive. I suspect we should do the same with that
method (especially given the apparent number of systems that use it for
regular password auth), but in the absence of systems to test against I've
not actually made the change. (I'm worried that the `partial success' field
might not be set correctly in a multi-stage authentication, for instance.)
[originally from svn r4850]
authentication state, a failed `password' authentication in SSH-2 was
sending us back to trying `none' and `keyboard-interactive' each time
round, which uses up OpenSSH's quota of authentication attempts rather
quickly. Added a check for `cfg.change_username' to the logic which
sends us back to the start.
[originally from svn r4849]
pointed out that Plink would attempt to use a zero-length username iff
a remote command was specified (because the FLAG_INTERACTIVE test was
erroneously combined with the no-username test).
I don't think this will break non-interactive use; in the cases which
behave differently, Plink would be attempting to use the empty
username, which was almost certainly wrong, whereas now it will give a
prompt (which can be avoided with -batch as usual).
(Although perhaps we should attempt to use a local username as a guess for
the remote username, as PSCP does? I've not done this.)
[originally from svn r4831]
Also, I'm pretty sure that adding a source address to a remote SSH-2 forwarding
can never have worked, since we added an address string to the packet twice in
that case. OpenSSH 3.4p1 certainly doesn't like it (`Server has disabled port
forwarding' debug message). Fixed (and OpenSSH is happier now).
[originally from svn r4727]
mechanics means that each SSH-2 remote tunnel will sfree() something
random and thus have a chance of crashing or doing something else
bad, although it won't otherwise affect execution. Introduced in
1.319 [r4529] (some of my improved diagnostics). One day I'll make a
checkin to ssh.c without forgetting about the coroutines...
[originally from svn r4725]
[r4529 == 27193c4bf0]
fixing `vuln-ssh2-debug', by missing out a field. In most cases
(always_display = 0) we would log a zero-length or truncated message.
(Also add a prototype for ssh2_pkt_getbool().)
[originally from svn r4718]
This is disgustingly huge because old versions of OpenSSH got the message
format wrong, so we have to infer which format is in use. Tested with
Debian stable OpenSSH (3.4p1), with `uint32' packet, and lshd, which uses
the correct `string' packet, and also let me test "core dumped" and the
explanatory message.
[originally from svn r4653]
of the SSH servers I conveniently have access to (Debian stable OpenSSH --
3.4p1 -- and lshd) seem to take a blind bit of notice, but the channel
requests look fine to me in the packet log.
I've included all the signals explicitly defined by
draft-ietf-secsh-connect-19, but I've put the more obscure ones in a submenu
of the specials menu; there's therefore been some minor upheaval to support
such submenus.
[originally from svn r4652]
down. (A side effect of fixing this is that ssh->mainchain is set to NULL
when it closes, which might avoid other sorts of trouble.)
While we're here, don't bother offering SSH1_MSG_IGNORE if we believe the
remote will barf on it.
[originally from svn r4650]
into the Connection panel, and implemented support for the SSH2
"env" request. (I haven't yet found a server which accepts this
request, so although I've visually checked the packet log and it
looks OK, I haven't yet been able to do a full end-to-end test.)
Also, the `pty' backend reads this data and does a series of
`putenv' commands before launching the shell or application.
This is mostly because in last week's UTF-8 faffings I got
thoroughly sick of typing `export LANG=en_GB.UTF-8' every time I
started a new testing pterm, and it suddenly occurred to me that
this would be precisely the sort of thing you'd want to have pterm
set up for you, particularly since you can configure it alongside
the translation settings and so you can ensure they match up
properly.
[originally from svn r4645]
PuTTY / Plink not to run a remote shell/command at all. Supported in
the GUI configuration and via the (OpenSSH-like) -N command-line
option.
No effort is currently made to arrange `nice' UI properties. If you
do this in GUI PuTTY, a full-size terminal window will still be
created, and will sit there with almost nothing in it throughout
your session. If you do it in Plink, Plink will not accept any kind
of request to terminate gracefully; you'll have to ^C or kill it.
Nonetheless, even this little will be useful to some people...
[originally from svn r4614]
by default (although they can be included). There's also an option to remove
session data, which is good both for privacy and for reducing the size of
logfiles.
[originally from svn r4593]
enable login with this version. (I'd suspected as much -- see ssh.c CVS
log 1.299 [r3359] -- and Geoffrey Hughes has now confirmed this.)
[originally from svn r4566]
[r3359 == d534d4e104]
truncated - it was from OpenSSH on HP/UX and had all sorts of stuff in it
("last successful login" etc).
Bodged it by bumping up the space allocated in the fixed array for a password
prompt. Also added an indication that the prompt is being truncated, as
required by draft-ietf-secsh-auth-kbdinteract-06.
(NB that before this checkin, there was a more-or-less harmless buffer overread
where if we ever received a keyboard-interactive prompt with echo=1, we'd
probably spew goo on the terminal; fixed now.)
[originally from svn r4476]
forwarded X11 connection is now logged as well as the closing; but we also
log the peer IP/port in case it's interesting, and log the reason for
refusing to honour a channel open.
[originally from svn r4451]
handle source address spec ":10023"; ignoring' type errors in the
Event Log. The forwarding would go ahead as normal so this is
cosmetic. Fixed.
[originally from svn r4392]
No very good reason, but I've occasionally wanted to frob it to see if it
makes any difference to problems I'm having, and it was easy.
Tested that it does actually cause keepalives on Windows (with tcpdump);
should also work on Unix. Not implemented on Mac (does nothing), but then
neither is TCP_NODELAY.
Quite a big checkin, much of which is adding `keepalive' alongside `nodelay'
in network function calls.
[originally from svn r4309]
account of coroutines and used local variables over a crFoo. I believe the
impact was cosmetic, affecting the speeds reported in the Event Log only.
I've put the variables `ispeed' and `ospeed' in the main ssh_tag structure,
even though they're only live for a short duration; I did this rather than
create a new state struct for ssh1_protocol() (since ssh_tag already has
short-duration junk like portfwd_strptr).
[originally from svn r4272]
(we didn't before) - `ssh-termspeed'.
In the process, I've removed the individual controls on the Telnet and
Rlogin panels and replaced them with one on the Connection panel (since they
were backed by the same storage anyway).
The terminal speeds sent in SSH are logged in the Event Log.
[originally from svn r4133]
things; it called freebn on the DH gex values even if DH gex had not
taken place. Bug was trivially reproducible as a NULL-dereference
segfault by making any SSH2 connection with DH gex disabled. Should
now be fixed.
[originally from svn r3678]
functions have sprouted `**errorstr' arguments, which if non-NULL can
return a textual error message. The interface additions are patchy and
ad-hoc since this seemed to suit the style of the existing interfaces.
I've since realised that most of this is masked by sanity-checking that
gets done before these functions are called, but it will at least report
MAC failures and the like (tested on Unix), which was the original point
of the exercise.
Note that not everyone who could be using this information is at the
moment.
[originally from svn r3430]
sk_new() on invocation; these functions become responsible for (eventually)
freeing it. The caller must not do anything with 'addr' after it's been passed
in. (Ick.)
Why:
A SOCKS5 crash appears to have been caused by overzealous freeing of
a SockAddr (ssh.c:1.257 [r2492]), which for proxied connections is
squirreled away long-term (and this can't easily be avoided).
It would have been nice to make a copy of the SockAddr, in case the caller has
a use for it, but one of the implementations (uxnet.c) hides a "struct
addrinfo" in there, and we have no defined way to duplicate those. (None of the
current callers _do_ have a further use for the SockAddr.)
As far as I can tell, everything _except_ proxying only needs addr for the
duration of the call, so sk_addr_free()s immediately. If I'm mistaken, it
should at least be easier to find the offending free()...
[originally from svn r3383]
[r2492 == bdd6633970]
OSU VMS SSH server <http://kcgl1.eng.ohio-state.edu/~jonesd/ssh/>.
The changelog appears to indicate that the server was fixed for pwplain1 at
1.5alpha4, and for IGNORE and DEBUG messages at 1.5alpha6. However I'm going
to go on the reports we've had as I haven't tested this; and they indicate
only that 1.5alpha6 is known not to require any bug compatibility modes.
(I wasn't sure whether to add this at all, given that upgrading to version
OSU_1.5alpha6 is an easy way to fix the problem. However, there is precedent
for adding detection for old versions of servers which have since been fixed.)
[originally from svn r3359]
reading) in the zlib code when fed certain kinds of invalid data. As
a result, ssh.c now needs to be prepared for zlib_decompress_block
to return failure.
[originally from svn r3306]
with the crc32() function in the zlib interface. (Not that PuTTY
itself _uses_ zlib, but on Unix it's linked against libgtk which
uses libpng which uses zlib. And zlib has poor namespace management
so it defines this ridiculously intrusive function name. Arrrrgh.)
[originally from svn r3191]
callback function; it may return 0 to indicate that it doesn't have
an answer _yet_, in which case it will call the callback later on
when it does, or it may return 1 to indicate that it's got an answer
right now. The Windows agent_query() implementation is functionally
unchanged and still synchronous, but the Unix one is async (since
that one was really easy to do via uxsel). ssh.c copes cheerfully
with either return value, so other ports are at liberty to be sync
or async as they choose.
[originally from svn r3153]
credible effort to shut down open forwardings cleanly when the
owning SSH connection terminates abruptly (for whatever reason).
[originally from svn r3137]
time. This gives rise to a whole bunch of spare warnings, one or two
of which might have been actual bugs; now all resolved.
[originally from svn r3134]
