Jul 12, 2011

PuTTY version 0.61 is released

PuTTY version 0.61 is released

All the pre-built binaries, and the source code, are now available
from the PuTTY website at


It's been more than four years since 0.60 was released, and we've had
quite a lot of email asking if PuTTY was still under development, and
occasionally asking if we were even still alive. Well, we are, and it
has been! Sorry about the long wait.

New features in 0.61 include:

- Support for SSH-2 authentication using GSSAPI, on both Windows and
   Unix. Users in a Kerberos realm should now be able to use their
   existing Kerberos single sign-on in their PuTTY SSH connections.
   (While this has been successfully deployed in several realms, some
   small gaps are known to exist in this functionality, and we would
   welcome further testing and advice from Kerberos experts.)

- On Windows: PuTTY's X11 forwarding can now authenticate with the
   local X server, if you point it at an X authority file where it can
   find the authentication details. So you can now use Windows PuTTY
   with X forwarding and not have to open your X server up to all
   connections from localhost.

- On Windows: the Appearance panel now includes a checkbox to allow
   the selection of non-fixed-width fonts, which PuTTY will coerce
   into a fixed-width grid in its terminal emulation. In particular,
   this allows you to use GNU Unifont and Fixedsys Excelsior. (Thanks
   to Randall Munroe for a serious suggestion that inspired this.)

- On Unix: the GTK port now compiles with GTK version 2, which is
   generally shinier and in particular provides access to client-side
   scalable fonts. (Though, unlike some GTK 2 applications, we have
   retained support for old-style X11 server-side bitmap fonts too.)

   Some Linux distributions have been shipping pre-release versions of
   GTK 2 PuTTY for years, so this won't be a surprise to anyone using
   Unix PuTTY or pterm via Debian or Ubuntu. But this is the first
   official release containing that functionality.

- A small but important feature: you can now manually tell PuTTY the
   name of the host you expect to end up talking to, in cases where
   that differs from where it's physically connecting to (e.g. when
   port forwarding). If you do this, the host key will be looked up
   and cached under the former name.

- Assorted optimisation and speedup work. SSH key exchange should be
   faster by about a factor of three compared to 0.60; SSH-2
   connections are started up in a way that reduces the number of
   network round trip delays; SSH-2 window management has also been
   revised to reduce round trip delays during any large-volume data
   transfer (including port forwardings as well as SFTP/SCP).

- Support for OpenSSH's security-tweaked form of SSH compression (so
   PuTTY can now use compression again when talking to modern OpenSSH

- Support for Windows 7's new user interface features. The new Aero
   window management should now play nicely with PuTTY's complicated
   window resize handling, and Windows 7 jump lists are now supported
   so you can launch saved sessions directly from the taskbar.

Bug fixes include:

- Better support for importing OpenSSH private keys in PuTTYgen: we
   now support key files encrypted with AES, and we cope with keys
   whose primes are listed in the opposite order from the one we

- Corruption of data transferred over port forwardings is _probably_
   fixed (though there is the possibility that it was due to more than
   one bug, so we want to hear about it if it's still happening).

- Crashing when the server unexpectedly closes the network connection
   should be fixed. On Windows Vista and 7, PuTTY also no longer goes
   into a tight loop in this situation.

- PSCP and PSFTP should no longer hang on exit in some failure cases.

- On Windows: fixed a hang in the serial port back end.

- On Windows: PuTTY reads from the clipboard in a separate thread
   from its main one, which fixes a deadlock when trying to cut and
   paste into PuTTY from an X11 application or Remote Desktop session
   tunnelled through the same instance of PuTTY.

- Many, many other bug fixes.

Enjoy using PuTTY!