I am developing an Angular 6 PWA served on IIS 8 (windows server 2012 R2) but i am facing various issues with https certificates: google chrome (both the android and desktop version) warns me that the cipher i use it's obsolete (i already tried to change them with iiscrypto with no luck).
Actually, i am stuck with cipher AES_256_CBC HMAC-SHA
but still chrome tells me it's obsolete.
How can i resolve this issue and securely serve my application over HTTPS (with full PWA support?).
P.S. Keep in mind using let's encrypt it's not an option: i need to distribute this application amongst many costumers, and i can't keep renew certificates every 90 days.