'Assert that we get an errback if we try to sign data using a key that
wasn\'t added.'

def test_signDataRSAErrbackOnUnknownBlob(self):

    del self.server.factory.keys[self.rsaPublic.blob()]
    d = self.client.signData(self.rsaPublic.blob(), 'John    Hancock')
    self.pump.flush()
    return self.assertFailure(d, ConchError)
