Decrypting a token in NodeJS with a JCEKS keystore

In this scenario I'm getting token encrypted at origin with the one secret key in a JCEKS keystore. The token goes into a NodeJS server, where it should be unencrypted to use the data in there. As far as I understand, the private key to decrypt the token cannot be extracted from that format, so decrypting it simply using the crypto module won't do. I've played around with node-keytool, and gotten as far as listing the keys, based on the example here: https://github.com/FrankGrimm/node-keytool/blob/master/examples/listcontent.js.

However, I'm at a complete loss as how to use that module to decrypt the token. Any suggestions on how to do so, whether using that module or another, would be greatly appreciated.

It seems like it can't be done, or at least not without a lot of work. Easier to write a decrypter in Java and then make a module in Node, like so:

const exec = require('child_process').exec; const fs = require('fs');

const start = function (data, resolve, reject) {
    let child = exec('java -jar java/out/artifacts/decrypter_jar/decrypter.jar ' + data,
    function (error, stdout, stderr){
        console.log('Output -> ' + stdout);
        if(stdout){
            resolve(stdout);
        }
        else {
            reject('Empty response from JAR');
            return;
        }
        if(error !== null){
            console.log("Error -> "+error);
            reject(error);
        }
    });


};

module.exports = {start};