Normally data transfer rate on contactless channel remains slow because of noise. To sign certain data needs data in some kbytes to cross this channel will be tough job if not impossible. If contactless channel is stable then it should be possible.

https://www.tegona.com/  is one such software house can offer you middleware /software services that enables digital signature using smartcard (contact/contactless/ mobile – android )

https://www.bit4id.com/en/ is another one

Technically it should be possible on both contact and contactless interface. May be your current infrastructure is supporting only contact interface. So if you are able to do it on contact interface now, you should be able to do on contactless as well if you have the right infrastructure