mirror of
https://git.tartarus.org/simon/putty.git
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d515e4f1a3
This is a heavily edited (by me) version of a patch originally due to Nico Williams and Viktor Dukhovni. Their comments: * Don't delegate credentials when rekeying unless there's a new TGT or the old service ticket is nearly expired. * Check for the above conditions more frequently (every two minutes by default) and rekey when we would delegate credentials. * Do not rekey with very short service ticket lifetimes; some GSSAPI libraries may lose the race to use an almost expired ticket. Adjust the timing of rekey checks to try to avoid this possibility. My further comments: The most interesting thing about this patch to me is that the use of GSS key exchange causes a switch over to a completely different model of what host keys are for. This comes from RFC 4462 section 2.1: the basic idea is that when your session is mostly bidirectionally authenticated by the GSSAPI exchanges happening in initial kex and every rekey, host keys become more or less vestigial, and their remaining purpose is to allow a rekey to happen if the requirements of the SSH protocol demand it at an awkward moment when the GSS credentials are not currently available (e.g. timed out and haven't been renewed yet). As such, there's no need for host keys to be _permanent_ or to be a reliable identifier of a particular host, and RFC 4462 allows for the possibility that they might be purely transient and only for this kind of emergency fallback purpose. Therefore, once PuTTY has done a GSS key exchange, it disconnects itself completely from the permanent host key cache functions in storage.h, and instead switches to a _transient_ host key cache stored in memory with the lifetime of just that SSH session. That cache is populated with keys received from the server as a side effect of GSS kex (via the optional SSH2_MSG_KEXGSS_HOSTKEY message), and used if later in the session we have to fall back to a non-GSS key exchange. However, in practice servers we've tested against do not send a host key in that way, so we also have a fallback method of populating the transient cache by triggering an immediate non-GSS rekey straight after userauth (reusing the code path we also use to turn on OpenSSH delayed encryption without the race condition). |
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|---|---|---|
| charset | ||
| contrib | ||
| doc | ||
| icons | ||
| testdata | ||
| unix | ||
| windows | ||
| .gitignore | ||
| aqsync.c | ||
| be_all_s.c | ||
| be_all.c | ||
| be_misc.c | ||
| be_none.c | ||
| be_nos_s.c | ||
| be_nossh.c | ||
| be_ssh.c | ||
| Buildscr | ||
| Buildscr.cv | ||
| callback.c | ||
| cgtest.c | ||
| CHECKLST.txt | ||
| cmdgen.c | ||
| cmdline.c | ||
| conf.c | ||
| config.c | ||
| configure.ac | ||
| cproxy.c | ||
| dialog.c | ||
| dialog.h | ||
| errsock.c | ||
| fuzzterm.c | ||
| import.c | ||
| int64.c | ||
| int64.h | ||
| LATEST.VER | ||
| ldisc.c | ||
| ldisc.h | ||
| ldiscucs.c | ||
| LICENCE | ||
| licence.pl | ||
| logging.c | ||
| minibidi.c | ||
| misc.c | ||
| misc.h | ||
| miscucs.c | ||
| mkauto.sh | ||
| mkfiles.pl | ||
| mksrcarc.sh | ||
| mkunxarc.sh | ||
| network.h | ||
| nocmdline.c | ||
| nocproxy.c | ||
| nogss.c | ||
| noprint.c | ||
| noshare.c | ||
| noterm.c | ||
| notiming.c | ||
| pageant.c | ||
| pageant.h | ||
| pgssapi.c | ||
| pgssapi.h | ||
| pinger.c | ||
| portfwd.c | ||
| pproxy.c | ||
| proxy.c | ||
| proxy.h | ||
| pscp.c | ||
| psftp.c | ||
| psftp.h | ||
| putty.h | ||
| puttymem.h | ||
| puttyps.h | ||
| raw.c | ||
| README | ||
| Recipe | ||
| release.pl | ||
| resource.h | ||
| rlogin.c | ||
| sercfg.c | ||
| sessprep.c | ||
| settings.c | ||
| sftp.c | ||
| sftp.h | ||
| sign.sh | ||
| ssh.c | ||
| ssh.h | ||
| sshaes.c | ||
| ssharcf.c | ||
| sshbcrypt.c | ||
| sshblowf.c | ||
| sshblowf.h | ||
| sshbn.c | ||
| sshbn.h | ||
| sshccp.c | ||
| sshcrc.c | ||
| sshcrcda.c | ||
| sshdes.c | ||
| sshdh.c | ||
| sshdss.c | ||
| sshdssg.c | ||
| sshecc.c | ||
| sshecdsag.c | ||
| sshgss.h | ||
| sshgssc.c | ||
| sshgssc.h | ||
| sshmd5.c | ||
| sshnogss.c | ||
| sshprime.c | ||
| sshpubk.c | ||
| sshrand.c | ||
| sshrsa.c | ||
| sshrsag.c | ||
| sshsh256.c | ||
| sshsh512.c | ||
| sshsha.c | ||
| sshshare.c | ||
| sshzlib.c | ||
| storage.h | ||
| telnet.c | ||
| terminal.c | ||
| terminal.h | ||
| testback.c | ||
| testbn.c | ||
| time.c | ||
| timing.c | ||
| tree234.c | ||
| tree234.h | ||
| version.c | ||
| version.h | ||
| wcwidth.c | ||
| wildcard.c | ||
| x11fwd.c | ||
This is the README for the source archive of PuTTY, a free Windows
and Unix Telnet and SSH client.
If you want to rebuild PuTTY from source, we provide a variety of
Makefiles and equivalents. (If you have fetched the source from
Git, you'll have to generate the Makefiles yourself -- see
below.)
There are various compile-time directives that you can use to
disable or modify certain features; it may be necessary to do this
in some environments. They are documented in `Recipe', and in
comments in many of the generated Makefiles.
For building on Windows:
- windows/Makefile.vc is for command-line builds on MS Visual C++
systems. Change into the `windows' subdirectory and type `nmake
-f Makefile.vc' to build all the PuTTY binaries.
As of 2017, we successfully compile PuTTY with both Visual Studio
7 (2003) and Visual Studio 14 (2015), so our guess is that it will
probably build with versions in between those as well.
(The binaries from Visual Studio 14 are only compatible with
Windows XP and up. Binaries from Visual Studio 7 ought to work
with anything from Windows 95 onward.)
- Inside the windows/MSVC subdirectory are MS Visual Studio project
files for doing GUI-based builds of the various PuTTY utilities.
These have been tested on Visual Studio 7 and 10.
You should be able to build each PuTTY utility by loading the
corresponding .dsp file in Visual Studio. For example,
MSVC/putty/putty.dsp builds PuTTY itself, MSVC/plink/plink.dsp
builds Plink, and so on.
- windows/Makefile.mgw is for MinGW / Cygwin installations. Type
`make -f Makefile.mgw' while in the `windows' subdirectory to
build all the PuTTY binaries.
MinGW and friends can lag behind other toolchains in their support
for the Windows API. Compile-time levers are provided to exclude
some features; the defaults are set appropriately for the
'mingw-w64' cross-compiler provided with Ubuntu 14.04. If you are
using an older toolchain, you may need to exclude more features;
alternatively, you may find that upgrading to a recent version of
the 'w32api' package helps.
- windows/Makefile.lcc is for lcc-win32. Type `make -f
Makefile.lcc' while in the `windows' subdirectory. (You will
probably need to specify COMPAT=-DNO_MULTIMON.)
- Inside the windows/DEVCPP subdirectory are Dev-C++ project
files for doing GUI-based builds of the various PuTTY utilities.
The PuTTY team actively use Makefile.vc (with VC7/10) and Makefile.mgw
(with mingw32), so we'll probably notice problems with those
toolchains fairly quickly. Please report any problems with the other
toolchains mentioned above.
For building on Unix:
- unix/configure is for Unix and GTK. If you don't have GTK, you
should still be able to build the command-line utilities (PSCP,
PSFTP, Plink, PuTTYgen) using this script. To use it, change into
the `unix' subdirectory, run `./configure' and then `make'. Or you
can do the same in the top-level directory (we provide a little
wrapper that invokes configure one level down), which is more like
a normal Unix source archive but doesn't do so well at keeping the
per-platform stuff in each platform's subdirectory; it's up to you.
- unix/Makefile.gtk and unix/Makefile.ux are for non-autoconfigured
builds. These makefiles expect you to change into the `unix'
subdirectory, then run `make -f Makefile.gtk' or `make -f
Makefile.ux' respectively. Makefile.gtk builds all the programs but
relies on Gtk, whereas Makefile.ux builds only the command-line
utilities and has no Gtk dependence.
- For the graphical utilities, any of Gtk+-1.2, Gtk+-2.0, and Gtk+-3.0
should be supported. If you have more than one installed, you can
manually specify which one you want by giving the option
'--with-gtk=N' to the configure script where N is 1, 2, or 3.
(The default is the newest available, of course.) In the absence
of any Gtk version, the configure script will automatically
construct a Makefile which builds only the command-line utilities;
you can manually create this condition by giving configure the
option '--without-gtk'.
- pterm would like to be setuid or setgid, as appropriate, to permit
it to write records of user logins to /var/run/utmp and
/var/log/wtmp. (Of course it will not use this privilege for
anything else, and in particular it will drop all privileges before
starting up complex subsystems like GTK.) By default the makefile
will not attempt to add privileges to the pterm executable at 'make
install' time, but you can ask it to do so by running configure
with the option '--enable-setuid=USER' or '--enable-setgid=GROUP'.
- The Unix Makefiles have an `install' target. Note that by default
it tries to install `man' pages; if you have fetched the source via
Git then you will need to have built these using Halibut
first - see below.
- It's also possible to build the Windows version of PuTTY to run
on Unix by using Winelib. To do this, change to the `windows'
directory and run `make -f Makefile.mgw CC=winegcc RC=wrc'.
All of the Makefiles are generated automatically from the file
`Recipe' by the Perl script `mkfiles.pl' (except for the Unix one,
which is generated by the `configure' script; mkfiles.pl only
generates the input to automake). Additions and corrections to Recipe,
mkfiles.pl and/or configure.ac are much more useful than additions and
corrections to the actual Makefiles, Makefile.am or Makefile.in.
The Unix `configure' script and its various requirements are generated
by the shell script `mkauto.sh', which requires GNU Autoconf, GNU
Automake, and Gtk; if you've got the source from Git rather
than using one of our source snapshots, you'll need to run this
yourself. The input file to Automake is generated by mkfiles.pl along
with all the rest of the makefiles, so you will need to run mkfiles.pl
and then mkauto.sh.
Documentation (in various formats including Windows Help and Unix
`man' pages) is built from the Halibut (`.but') files in the `doc'
subdirectory using `doc/Makefile'. If you aren't using one of our
source snapshots, you'll need to do this yourself. Halibut can be
found at <https://www.chiark.greenend.org.uk/~sgtatham/halibut/>.
The PuTTY home web site is
https://www.chiark.greenend.org.uk/~sgtatham/putty/
If you want to send bug reports or feature requests, please read the
Feedback section of the web site before doing so. Sending one-line
reports saying `it doesn't work' will waste your time as much as
ours.
See the file LICENCE for the licence conditions.