Daniel Meidlinger reports that at least one Windows machine which is
not obviously otherwise misconfigured will respond to our
SetEntriesInAcl call with odd errors like ERROR_NONE_MAPPED or
ERROR_TRUSTED_RELATIONSHIP_FAILURE. This is apparently to do with
failure to convert the names "EVERYONE" and "CURRENT_USER" used in the
ACL specification to SIDs. (Or perhaps only one of them is the problem
- I didn't investigate in that direction.)
If we instead construct a fully SID-based ACL, using the well-known
world SID in place of EVERYONE and calling our existing get_user_sid
routine in place of CURRENT_USER, he reports that the problem goes
away, so let's do that instead.
While I'm here, I've slightly simplified the function prototype of
make_private_security_descriptor(), by turning 'networksid' into an
internal static that we can reuse in subsequent calls once we've set
it up. (Mostly because I didn't fancy adding another two pointless
parameters at every call site for the two new SIDs.)
[originally from svn r10096]
The basic strategy is described at the top of the new source file
sshshare.c. In very brief: an 'upstream' PuTTY opens a Unix-domain
socket or Windows named pipe, and listens for connections from other
PuTTYs wanting to run sessions on the same server. The protocol spoken
down that socket/pipe is essentially the bare ssh-connection protocol,
using a trivial binary packet protocol with no encryption, and the
upstream has to do some fiddly transformations that I've been
referring to as 'channel-number NAT' to avoid resource clashes between
the sessions it's managing.
This is quite different from OpenSSH's approach of using the Unix-
domain socket as a means of passing file descriptors around; the main
reason for that is that fd-passing is Unix-specific but this system
has to work on Windows too. However, there are additional advantages,
such as making it easy for each downstream PuTTY to run its own
independent set of port and X11 forwardings (though the method for
making the latter work is quite painful).
Sharing is off by default, but configuration is intended to be very
easy in the normal case - just tick one box in the SSH config panel
and everything else happens automatically.
[originally from svn r10083]
It was only actually used in X11 and port forwarding, to find internal
state structures given only the Socket that ssh.c held. So now that
that lookup has been reworked to be the sensible way round,
private_ptr is no longer used for anything and can be removed.
[originally from svn r10075]
This commit adds two new support modules, winnpc.c and winnps.c, which
deal respectively with being a client and server of a Windows named
pipe (which, in spite of what Unix programmers will infer from that
name, is actually closer to Windows's analogue of a Unix-domain
socket). Each one provides a fully featured Socket wrapper around the
hairy Windows named pipe API, so that the rest of the code base should
be able to use these interchangeably with ordinary sockets and hardly
notice the difference.
As part of this work, I've introduced a mechanism in winhandl.c to
permit it to store handles of event objects on behalf of other Windows
support modules and deal with passing them to applications' main event
loops as necessary. (Perhaps it would have been cleaner to split
winhandl.c into an event-object tracking layer analogous to uxsel, and
the handle management which is winhandl.c's proper job, but this is
less disruptive for the present.)
[originally from svn r10069]
