How to work with HTTPPROPERTY Base64toBinary?

Hi, I am trying to develop an outbound REST service operation with which files can be uploaded into AWS S3. As per Amazon's documentation, content of the file has to be placed in request body, and in PeopleSoft API we have a SetContentString() method in Message class to do this, but it only works when the file itself is plain text. So what can we do if the file is binary? Base64 encoding is apparently a solution, and I noticed a HTTPPROPERTY Base64toBinary has been provided to address this. So basically, when we need to upload a binary file into