driver = webdriver.PhantomJS(service_args=['--ignore-ssl-errors=true',
    '--ssl-client-certificate-file=C:\tmp\\clientcert.cer',
    '--ssl-client-key-file=C:\tmp\\clientcert.key',
    '--ssl-client-key-passphrase=1111'])
driver.set_window_size(1280, 1024)
driver.get('https://localhost/test/')
driver.save_screenshot('screen.png')
driver.quit()
Как установить SSL-сертификат в Python phantomjs?