calling imported JS function slows down by 20x

use-case: only if user password changes (one time a month) I must RSA encrypt this password and send base64 to server.

must work on Android and iOS and I couldn't figure out HowTo do this from C++.

because it's not in daily use I was looking for a JS library from http://www-cs-students.stanford.edu/~tjw/jsbn/

Implemenation was easy: add .js to resource, import into QML, then call this function:

function doEncrypt() {
    var rsa = new MyRsa.RSAKey();
    rsa.setPublic(dataServer.modulusHex(), "10001")
    var res = rsa.encrypt(pwText.text)
    if(res) {
        return MyRsa.linebrk(res, 64)
    } else {
        return ""
    }
}

this works well for 5.9.x, 5.10.x, 5.11.x but slows down by 20x on Qt 5.12 Beta 3 from 5.11.2

• macOS: from 5 ms to 1211 ms
• Android: from 466 ms to 7403 ms
• iOS: from 77 ms to 1680 ms

I prepared a very simple to use test project, so you can test easy:

https://github.com/ekke/encrypt_text