How to get vendor signature in contract document

Hello

I have a requirement where scanned contract copy ( pdf / doc ) would be uploaded to CLM and would be circulated to supplier  as part of workflow in their supplier portal for sign off . My requirement is to get a supplier's signature on the document and upload it back to CLM

Is there anyway I can achieve this functionality ?

System I am using is sourcing/clm  7.0

Thanks in advance

Sudipta