So I'm stuck with this problem:

IE Edge no longer allow applets, activeX, etc. ,

and I have this applet that is used for digital signature,

the idea is to extract the private key from the KEY file in the client side, in that way the private key never leaves the client's computer, that is a requirement for security, it can't be avoid :(

I'm looking for APIs or frameworks, but I can't found a way to solve this,

with jsrsasign the examples uses a PEM file but my users have .CER + .KEY + password, in java I can do it, but I need to do it in javascript or in something on the client side.

and, reading the Web Cryptography API and some examples I found, they generate NEW private and public keys to sign BUT they never READ an existing CERTIFICATE

does anybody have this problem or know a framework I could use?
please heeeelp!