How to recover a RSA public key from a byte[] array?

Question

I'm wondering if it's possible to recover a RSA public key that I have converted to byte array previously.

byte[] keyBytes = publicKey.getEncoded();

Thanks for the help.

Answer 1

PublicKey publicKey = 
    KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(bytes));

For more info see this tutorial

Answer 2

For others who want to get private key instead of public key from byte array:

PrivateKey privateKey = KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(privateKeyBytes));

Answer 3

Great answer. Thanks for the link. Just for complete, I found this Converted secret key into bytes, how to convert it back to secrect key?

SecretKey key2 = new SecretKeySpec(data, 0, data.length, "DES");

and just worked very well.