Question

I have a custom public key class that generates mod and exp explicitly instead of using the publickey from the java.security. Now how do I initialize the cipher variable for encryption with the mod and exp that I have .

Cipher cipher = Cipher.getInstance("RSA");
String mod = pbkey.getMod();
String exp = pbkey.getExp();

How to achieve equivalent of

 cipher.init(Cipher.ENCRYPT_MODE, java.security.PublicKeyVariable); 

using the mod and exp?

thanks
Nohsib

Answer 1

Build a RSAPublicKeySpec, pass it to KeyFactory.generatePublic, then pass the result as the second argument to cipher.init. See this tutorial.