Squid + ClamAV + i-cap: Scanning proxy for uploaded files?
Solution 1:
I think this is a limitation in c-icap. This reference is a bit old, but the main developer of c-icap says:
It has to do with the way the data coded in POST requests. When the POST request will contain multipart form data will not work well.
This means that uploads aren't well supported on c-icap. It seems the only option you have is to replace c-icap with another ICAP server but, from my research, it seems that all the others are rather old or abandoned.