To extend the background with particular ration Automated

Hi,

I wanted to crop the image in ratio 1:1 and wanted to extend the background from two sides only whether it is from the top an bottom or left and righe side. The thing is I wanted to crop the image tightly where it touches the longest side first without trimming the product. So I need to enlarge the cropping area manually. There are many images i have to work on, so it will take much time manually. Please advise how can I do this automatically which will help me to reduce the time.