Just-ask is a simple ssh-askpass tool. It's for confirming or denying the use of an ssh key via ssh-agent. Also it's available for all platforms that golang supports.
go get -v github.com:frzifus/just-ask
cd $GOPATH/src/git.klimlive.de/frzifus/just-ask
# linux64
GOOS=linux GOARCH=amd64 go build
# arm
GOOS=linux GOARCH=arm go build
# win64
GOOS=windows GOARCH=amd64 go build
Execute as privileged user
# install
$ cp just-ask /usr/local/bin/
$ pushd /usr/local/bin
$ ln -s ssh-askpass /usr/local/bin/just-ask
$ popd
# uninstall
$ rm /usr/local/bin/just-ask
$ unlink /usr/local/bin ssh-askpass