Non-interactive password check

[Alexander Steinert <stony8@gmx.de>]

Currently I'm building a web application using python. The database only
stores a login name and an account name (e.g. 'john' and
'john.doe@otherserver.somewhere.else') but no password. (This is
invariant.)

On session start the user sends his login name and the password for the
remote account. I want to check the authenticity by something like
trying to ssh into the remote account and immediately logout again.  The
unix user doing this is the owner of the apache process.

Unfortunately this approach needs interaction (enter the password,
logout). I was not surprised to find no option in ssh's man page to give
the password on the command line.

Do you know any way to make ssh less interactive?

Stony