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Commit Graph

475 Commits

Author SHA1 Message Date
Ben Harris
3ffd1fbe38 Use preprocessor trickery to make the signal translation mechanism a little
less hideous.  The output of the preprocessor should be basically unchanged.

[originally from svn r7294]
2007-02-17 22:33:11 +00:00
Ben Harris
f69a0cf005 ssh2_set_window checks whether the channel is being closed, so there's no
need to check that before calling it.

[originally from svn r7293]
2007-02-17 22:15:57 +00:00
Ben Harris
91694cb3a2 When emitting SSH_MSG_IGNORE to protect against known-IV attacks on CBC,
remember to put an empty string in it rather than sending a completely
empty packet.  This should help with those servers (notably RomSShell)
that actually check the contents of SSH_MSG_IGNORE.

[originally from svn r7236]
2007-02-06 13:57:27 +00:00
Ben Harris
2069720687 Fix compiles on GCC 3.3, which doesn't know about assert(0);
[originally from svn r7130]
2007-01-20 20:05:46 +00:00
Simon Tatham
6716b1513e Flag user cancellation of authentication as a clean exit, so that it
will close the window even in `close window only on clean exit'
mode. Also, while I'm here, arrange a suitable exit code for
"exit-signal".

[originally from svn r7121]
2007-01-17 18:38:45 +00:00
Simon Tatham
42801b7e9e Get rid of all the MSVC warnings.
[originally from svn r7086]
2007-01-09 18:24:07 +00:00
Simon Tatham
274f6a60f7 Fix ssh2-cisco-pw-pad by reverting r5122. However, I've kept the
ability to easily re-enable the r5122 behaviour, in case we need to
conditionally switch between the two at a later date.

[originally from svn r7073]
[r5122 == 8a20515844]
[this svn revision also touched putty-wishlist]
2007-01-07 14:30:24 +00:00
Jacob Nevins
cd94e3bc3c Patch from Colin Watson intended to give a clean Unix compile with GCC 4.
(Since we choose to compile with -Werror, this is particularly important.)

I haven't yet checked that the resulting source actually compiles cleanly with
GCC 4, hence not marking `gcc4-warnings' as fixed just yet.

[originally from svn r7041]
2006-12-30 23:00:14 +00:00
Jacob Nevins
64f19d46d8 Minor semantic tweak to bug-compatibility modes: make
BUG_NEEDS_SSH1_PLAIN_PASSWORD do exactly what it says on the tin, independent
of whether BUG_CHOKES_ON_SSH1_IGNORE is set.

This is invisible in the default configuration, as all servers marked as having
the second bug have the first one too, but it would allow one to manually
configure PuTTY to cope with a SSH-1 server that got upset by ignore messages
during authentication, but was fine with their use as keepalives.

[originally from svn r6876]
2006-10-22 19:51:28 +00:00
Jacob Nevins
2afdb02660 I seem to have slightly funted Plink's display of banners etc in r6437, oops.
Fixed.

[originally from svn r6846]
[r6437 == 8719f92c14]
2006-09-05 21:41:38 +00:00
Jacob Nevins
e67b9cfd78 Slight change to password expiry UI for the benefit of Cisco servers, which
are as usual slightly odd.

[originally from svn r6845]
2006-09-05 21:39:30 +00:00
Simon Tatham
8b11c26c57 New logging mode, which records the exact bytes sent over the wire
in an SSH connection _in addition_ to the decrypted packets. This
will hopefully come in useful for debugging wire data corruption
issues: you can strace the server, enable this mode in the client,
and compare the sent and received data.

I'd _like_ to have this mode also log Diffie-Hellman private
exponents, session IDs, encryption and MAC keys, so that the
resulting log file could be used to independently verify the
correctness of all cryptographic operations performed by PuTTY.
However, I haven't been able to convince myself that the security
implications are acceptable. (It doesn't matter that this
information would permit an attacker to decrypt the session, because
the _already_ decrypted session is stored alongside it in the log
file. And I'm not planning, under any circumstances, to log users'
private keys. But gaining access to the log file while the session
was still running would permit an attacker to _hijack_ the session,
and that's the iffy bit.)

[originally from svn r6835]
2006-08-29 19:07:11 +00:00
Jacob Nevins
74278dcd64 Minor tweaks to -nc:
- log host:port in event log
 - add -nc to Plink usage message

[originally from svn r6825]
2006-08-28 17:47:43 +00:00
Simon Tatham
631b494807 New command-line option in Plink (and PuTTY, though it's less useful
there): `plink host -nc host2:port' causes the SSH connection's main
channel to be replaced with a direct-tcpip connection to the
specified destination. This feature is mainly designed for use as a
local proxy: setting your local proxy command to `plink %proxyhost
-nc %host:%port' lets you tunnel SSH over SSH with a minimum of
fuss. Works on all platforms.

[originally from svn r6823]
2006-08-28 15:12:37 +00:00
Simon Tatham
c353c3cc97 The `socket' function in the backends is only ever checked to see if
it's NULL. Since we already have one back end (uxpty) which doesn't
in fact talk to a network socket, and may well have more soon, I'm
replacing this TCP/IP-centric function with a nice neutral
`connected' function returning a boolean. Nothing else about its
semantics has currently changed.

[originally from svn r6810]
2006-08-27 08:03:19 +00:00
Simon Tatham
2d633388a1 Return a non-zero exit code in the event of a fatal-error SSH
session termination. `Close window only on clean exit' was not
working properly on Unix in the absence of this:
notify_remote_exit() was being called and ssh_return_exitcode was
returning zero, causing gtk_main_quit() to be called, _before_
connection_fatal() happened.

[originally from svn r6801]
2006-08-26 09:21:52 +00:00
Jacob Nevins
7958a63147 Sprinkle some header comments in various files in an attempt to explain what
they're for.

[originally from svn r6639]
2006-04-23 18:26:03 +00:00
Jacob Nevins
078c516a45 Dimitry Andric spotted that DH gex with SHA-256 was overflowing a buffer.
Fixed, and added paranoia so that this shouldn't happen again.

[originally from svn r6606]
[this svn revision also touched putty-wishlist]
2006-03-12 19:24:05 +00:00
Jacob Nevins
2cf27e43bb Log the hash used for DH kex (now there's a choice).
[originally from svn r6605]
2006-03-12 15:39:19 +00:00
Simon Tatham
fdee25e1f6 Daniel Meidlinger points out a redundant test :-)
[originally from svn r6579]
2006-02-19 22:37:31 +00:00
Simon Tatham
c2b2d9c539 Introduce a new checkbox and command-line option to inhibit use of
Pageant for local authentication. (This is a `don't use Pageant for
authentication at session startup' button rather than a `pretend
Pageant doesn't exist' button: that is, agent forwarding is
independent of this option.)

[originally from svn r6572]
2006-02-19 12:05:12 +00:00
Jacob Nevins
5d5abbf8d4 Apparently some SSH servers object to our claiming port-forwarded connections
to be from IP "client-side-connection". Claiming "0.0.0.0" instead seems to
work. Spotted by Brant Thomsen.

[originally from svn r6477]
[this svn revision also touched putty-wishlist]
2005-12-07 18:01:40 +00:00
Jacob Nevins
de945281fc r6437 broke the case where Pageant is running but contains no SSH-2 keys
that the SSH-2 server is happy with. Fixed, and since I'm here, fix
`pubkeyfile-and-pageant' as well (for SSH-1 and SSH-2).
Also, in SSH-2, we now reexamine "methods that can continue" for every
Pageant key offer, which is technically more correct although it seems
unlikely that it was causing any real problems.
(It's not entirely pretty, but neither was the old code. We could probably
do with some sort of abstraction for public/private keys to avoid carting
lots of fiddly bits of data around.)

[originally from svn r6459]
[r6437 == 8719f92c14]
[this svn revision also touched putty-wishlist]
2005-11-13 16:06:41 +00:00
Jacob Nevins
c4b2b493ff I broke the ability to cope with multiple consecutive k-i INFO_REQUESTS
in r6437. This ought to be better (but I can't test that case).

[originally from svn r6451]
[r6437 == 8719f92c14]
2005-11-09 23:19:33 +00:00
Jacob Nevins
29f1ae8a7e Fix minor hiccup in SSH-1 p-k auth.
[originally from svn r6447]
2005-11-04 23:31:11 +00:00
Jacob Nevins
4496d752a9 Placate a compiler warning introduced in r6437.
(I forgot we usually compile with -Werror on Unix, oops.)

[originally from svn r6446]
[r6437 == 8719f92c14]
2005-11-04 23:21:42 +00:00
Jacob Nevins
041e93f508 Fix for `ssh2-password-expiry'. Success case tested.
(Much easier since r6437, and actually works to boot.)

[originally from svn r6445]
[r6437 == 8719f92c14]
[this svn revision also touched putty-wishlist]
2005-11-04 14:49:22 +00:00
Jacob Nevins
6724e01956 (do_ssh2_authconn_state).method is redundant since r6437; remove.
Remove FIXMEs from .type assignments, as they look fine.

[originally from svn r6442]
[r6437 == 8719f92c14]
2005-10-31 22:43:51 +00:00
Jacob Nevins
8719f92c14 Revamp SSH authentication code so that user interaction is more
abstracted out; replace loops structured around a single interaction
per loop with less tortuous code (fixes: `ki-multiprompt-crash',
`ssh1-bad-passphrase-crash'; makes `ssh2-password-expiry' and
`proxy-password-prompt' easier).

The new interaction abstraction has a lot of fields that are unused in
the current code (things like window captions); this is groundwork for
`gui-auth'. However, ssh.c still writes directly to stderr; that may
want to be fixed.

In the GUI apps, user interaction is moved to terminal.c. This should
make it easier to fix things like UTF-8 username entry, although I
haven't attempted to do so. Also, control character filtering can be
tailored to be appropriate for individual front-ends; so far I don't
promise anything other than not having made it any worse.

I've tried to test this fairly exhaustively (although Mac stuff is
untested, as usual). It all seems to basically work, but I bet there
are new bugs. (One I know about is that you can no longer make the
PuTTY window go away with a ^D at the password prompt; this should be
fixed.)

[originally from svn r6437]
[this svn revision also touched putty-wishlist]
2005-10-30 20:24:09 +00:00
Jacob Nevins
c14f259ba2 Allow rsakey_pubblob() to return the key comment.
(like r6433 but for SSH-1)

[originally from svn r6434]
[r6433 == 49d2cf19ac]
2005-10-30 15:16:42 +00:00
Jacob Nevins
49d2cf19ac Add ability for ssh2_userkey_loadpub() to return the key comment.
(Not actually used currently, but it makes life easier for a patch I'm
working on.)

[originally from svn r6433]
2005-10-30 13:42:36 +00:00
Jacob Nevins
69ac38c1a8 Fix an error I introduced into SSH packet logging in r5642: some outgoing
packets over about 256 bytes would be logged with 12 bytes of preceding
garbage. (But the rest of the packet was logged in its entirety. This
holds for packets where (int(len/256)%2)==1, with an appropriate fudge
factor applied to `len'.) Ahem.

[originally from svn r6429]
[r5642 == c09d885b27]
2005-10-26 22:18:11 +00:00
Jacob Nevins
f2c17e2df8 Tweak to r6392: spell "MAC" thus.
[originally from svn r6399]
[r6392 == 8fb9bd0216]
2005-10-13 22:51:44 +00:00
Ben Harris
8fb9bd0216 Make SSH_MSG_DISCONNECT reasons less scary (without removing useful content).
[originally from svn r6392]
2005-10-13 21:51:38 +00:00
Ben Harris
c0d36aa00a Implement hmac-sha1-96. It's RECOMMENDED in the current transport draft,
and we don't have any strong reason not to implement it, for all that it's
rather pointless.

[originally from svn r6284]
2005-09-10 16:19:53 +00:00
Ben Harris
9131914278 Add support for diffie-hellman-group-exchange-sha256. Tested against a
patched OpenSSH server.  This is controlled by the same user settings
as diffie-hellman-group-exchange-sha1, which may not be optimal, especially
given that they're both referred to as dh-gex-sha1 in saved sessions.

[originally from svn r6272]
2005-09-04 14:53:39 +00:00
Ben Harris
a42d103cf9 Restructure things so that a single entry in the KEX preference list can
correspond to multiple SSH-2 KEX algorithms.  We already do the equivalent
for cipher algorithms.

[originally from svn r6262]
2005-09-03 13:41:43 +00:00
Jacob Nevins
d628d14e7f Check ssh->v2_session_id_len _after_ assigning to it.
[originally from svn r6260]
2005-09-02 10:51:09 +00:00
Ben Harris
a59356aa74 Add infrastructure for supporting multiple hashes in key exchange.
Nothing very surprising here.

[originally from svn r6251]
2005-08-31 20:43:06 +00:00
Ben Harris
11d5c791ac Rename ssh_md5 and ssh_sha1 to ssh_hmac_md5 and ssh_hmac_sha1 respectively.
This is to make room for a hash abstraction that's likely to want to use
ssh_sha1, at least.

[originally from svn r6249]
2005-08-31 19:11:19 +00:00
Ben Harris
7cceb6eeae Further progress in the direction of variable exchange hashes -- stash the
outgoing KEXINIT, and only start generating the exchange hash once we know
which KEX method we're using.

[originally from svn r6242]
2005-08-30 22:39:35 +00:00
Ben Harris
ef630659dd Beginnings of support for multiple exchange hashes in SSH-2: rather than
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]
2005-08-30 20:38:57 +00:00
Jacob Nevins
1e57b290b8 More versions of WeOnlyDo have the rekey bug (but they've fixed it now).
[originally from svn r6233]
2005-08-29 00:34:03 +00:00
Jacob Nevins
5661adabbc I think this should fix various problems with queued incoming data not being
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]
2005-08-26 21:17:49 +00:00
Ben Harris
575fa173d8 Florian Gaab reports that freeSSHd 1.0.7, which claims a "softwareversion"
of "WeOnlyDo-1.2.6", mishandles repeat key exchange.  Add it to the list.

[originally from svn r6200]
2005-08-22 20:07:46 +00:00
Ben Harris
ae64be506f draft-ietf-secsh-transport-24 says that only "SSH-" at the start of a line
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]
2005-07-24 13:46:14 +00:00
Ben Harris
7d49271ada Piers Finlayson reports that "DigiSSH_2.0" chokes (in a new and exciting
manner) on rekeys.  Add it to the list.

[originally from svn r6067]
2005-07-05 21:15:23 +00:00
Jacob Nevins
9897694920 Fix an apparently-harmless error spotted by Ben Rudiak-Gould:
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]
2005-06-21 20:13:48 +00:00
Ben Harris
4ad47722e8 Make the sanity-checks on the size of incoming packets much stricter. We now
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]
2005-06-20 13:56:30 +00:00
Ben Harris
93712a3ee1 A major purpose of PuTTY's memory-allocation functions is to succeed or die
trying, so there's no need to check their return values for NULL.  Spotted
by Ben Rudiak-Gould.

[originally from svn r5978]
2005-06-19 14:17:24 +00:00