Use WWW with a proxy

I currently have customers who are using a proxy in their company and thus can't use my Unity app, since I need to make HTTP requests. Since most posts I see about this subject are rather old, I was wondering if there is now a way to use a proxy with the WWW class? No, my app doesn't run in the webplayer If not possible, I started to use HttpWebRequest but I get a TlsException “The authentication or decryption has failed”. I tried what's explained in this answer but it didn't solve my problem: https://stackoverflow.com/questions/4926676/mono-https-webrequest-fails-with-the-authentication-or-decryption-has-failed Any idea ? Either for using Unity classes or C# classes?