cygport upload: patch for openssh 6.8p1

[Yaakov Selkowitz]

On Sun, 2015-05-24 at 12:32 -0400, Andrew Schulman wrote:
> Since the latest update to openssh, ssh-keygen's output format for key
> fingerprints has changed.  The default hash algorithm is now base64-encoded
> SHA256 instead of MD5, and the hash name precedes its value, like
> 
>     SHA256:lvRrjAXmEhzDp5kQqzelsei8s5hXJ+zLaqJ2yiGXmYc
> 
> This breaks the current logic for detecting key fingerprints in cygport's
> lib/pkg_upload.cygpart.  The attached patch fixes the problem.  (You might know
> a more precise regex for the base64-encoded hash value than I do.  I couldn't
> find any documentation of it anywhere, and just settled for
> 
>     SHA256:.{44}

There's another problem: this is new to 6.8; any out-of-date Cygwin
systems, or even current RHEL or Fedora 21 systems, won't have this, nor
do they support the -E flag which could be used to specify md5.

Any thoughts on a better regex or on keeping compatibility with other
systems?

--
Yaakov