Git ksshaskpass to play nice with https and kwallet

[Michael J Gruber <git@drmicha.warpmail.net>]

Checking out bitbucket and https, I came across a stupid issue between
the default KDE setup (SSH_ASKPASS=/usr/bin/ksshakspass and KDE wallet)
and the way we call the askpass helper, which makes the combo not work
out of the box.

For those interested in getting it to work (or learning why it does not
work out of the box), you can read the details formatted on my sparse
blog (brain dump)

http://grubix.blogspot.com/2011/10/git-ksshaskpass-to-play-nice-with-https.html

or below if you don't feel like clicking through.

Cheers
Michael

By default (with GIT_ASKPASS not set etc.), Git invokes $SSH_ASKPASS
when it needs to ask you for credential info. In a KDE environment,
SSH_ASKPASS is set to /usr/bin/ksshaskpass. So far so good.

But Git calls the askpass helper with a command line like
/usr/bin/ksshaskpass Username for 'bitbucket.org':
and once again with
/usr/bin/ksshaskpass Password for 'bitbucket.org':
So far so good.

But when asked to store the credentials in the KDE wallet, ksshaskpass
tries (too) hard to guess a good key from that line. And for both
invocations, it comes up with the same key (the URL), so that when the
password info is needed, the username info from the wallet is returned.
Authentication fails.
Far from good.

If you still want to use the KDE helpers, you can save the little snippet
#!/bin/bash
set $*
exec ksshaskpass $1\@$3
into ~/bin/git-ksshaskpass (and make it executable) and set

git config --global core.askpass ~/bin/git-ksshaskpass
Gitcha!

NB:

    tested and works with https
    not tested with other methods (use ssh-agent)
    new credential helper interface coming in Git after 1.7.7