Trying to init a Signature object from keypair generated by KEYUTIL.generateKeypair fails.

[trusktr]

I'm passing in a RSAKey object to Signature.init() and it fails with

Uncaught init failed.:[object Object]

My code looks like this:

           // in browser, using browserify.
            var rsa = require("jsrsasign");
            var keypair = rsa.KEYUTIL.generateKeypair("RSA", 256);
            console.log(keypair.prvKeyObj);
                var signature = new rsa.Signature({alg: "MD5withRSA"});
                signature.init(keypair.prvKeyObj); // ERROR HERE
                    signature.updateString("Hello");
                    var signatureValue = signature.sign();
                    console.log(signatureValue);

Why might the init fail?

[kjur]

I've tried your code on Node and gotten error like "key is too short for SigAlg".
Your RSA key seems to short for PKCS#1 padding for MD5withRSA.
For example key length is 512bit, it works fine.