Dropbear 2013.57 released

[Matt Johnston]

Hi all,

I've put up Dropbear 2013.57 as usual at
https://matt.ucc.asn.au/dropbear/dropbear.html

As well as a few bug fixes it has significant improvements
to the number of round trips required to set up a connection
- useful for high latency links.

Cheers,
Matt

2013.57 - Monday 15 April 2013

- Decreased connection setup time particularly with high latency connections,
  the number of round trips has been reduced for both client and server. 
  CPU time hasn't been changed.

- Client will send an initial key exchange guess to save a round trip.
  Dropbear implements an extension kexguess2 at matt.ucc.asn.au to allow the first
  packet guess to succeed in wider circumstances than the standard behaviour.
  When communicating with other implementations the standard behaviour is used.

- Client side: when public key or password authentication with
  $DROPBEAR_PASSWORD is used an initial authentication request will
  be sent immediately rather than querying the list of available methods.
  This behaviour is enabled by CLI_IMMEDIATE_AUTH option (on by default),
  please let the Dropbear author know if it causes any interoperability
  problems.

- Implement client escape characters ~. (terminate session) and 
  ~^Z (background session)

- Server will more reliably clean up utmp when connection is closed, reported by
  Mattias Walström

- Don't crash if /dev/urandom isn't writable (RHEL5), thanks to Scott Case

- Add "-y -y" client option to skip host key checking, thanks to Hans Harder

- scp didn't work properly on systems using vfork(), thanks to Frank Van Uffelen

- Added IUTF8 terminal mode support (Linux and Mac OS). Not standardised yet
though probably will be soon

- Some verbose DROPBEAR_TRACE output is now hidden unless $DROPBEAR_TRACE2
  enviroment variable is set

- Fix using asymmetric MAC algorithms (broke in )

- Renamed configure.in to configure.ac to quieten autoconf, from Mike Frysinger