Serialize and Deserialize an RSA public key

Question

KeyPairGenerator kpg = KeyPairGenerator.getInstance(\"RSA\");
kpg.initialize(1024);
KeyPair kp = kpg.genKeyPair();
Key publicKey = kp.getPublic();
Key privateKey = kp.ge         


        

Answer 1

Asymmetric keys like those from RSA are usually stored in X509 format. Therefor you can use X509EncodedKeySpecinstead.

A simple example is already in the Java 7 JavaDoc (just replace DSA with RSA): http://docs.oracle.com/javase/7/docs/api/java/security/KeyFactory.html

X509EncodedKeySpec bobPubKeySpec = new X509EncodedKeySpec(bobEncodedPubKey);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PublicKey bobPubKey = keyFactory.generatePublic(bobPubKeySpec);

If you need to deserialize the private from byte[], I've found that you must use PKCS8EncodedKeySpec.