Java: read public key files in PEM format
October 31, 2013 18:17:09 Last update: October 31, 2013 18:17:09
You have a PGP public in PEM format, which cannot be stored in a Java key store. But you have the PEM encoded public key file. This class reads the file and creates a public key class in Java.
Example key file:
Java code:
Example key file:
-----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzn34Tjjn8ngKRToZGi7A o5xeqJGDatvk9oEdRuDUEEfstKubN6UPRph5sPGNYXkdVXQDv8GQDZQo1+8PSGuq zClm9boFZSVkAmEWlFe2tYH7WQbZtM4gY0tameBoFHH1l8NpQlEXXBKn7Hj1O7xN EmiriS/5xDUstFmH5jQo/Q9cLh596Y3zK62ucScAt0iKMWT0h6XbLbRlCzPDmwyi 9VSbSYieZLsRcWKQ5d6nzJ3GFjwnWfx/OtryhtCQp8a8Z5luJWzyFgR+575WTQDf N4o6fu8KOptHhrGr1QI0Irqqi/+GrWmpENPmKDkrxWHzia+2zKuNB0vp8fHwwMH2 xwIDAQAB -----END PUBLIC KEY-----
Java code:
import java.io.*; import java.security.*; import java.security.spec.*; import sun.misc.BASE64Decoder; public class ReadPublicKey { public static void main(String[] args) throws Exception { // read key bytes FileInputStream in = new FileInputStream("mykey.pem.pub"); byte[] keyBytes = new byte[in.available()]; in.read(keyBytes); in.close(); String pubKey = new String(keyBytes, "UTF-8"); pubKey = pubKey.replaceAll("(-+BEGIN PUBLIC KEY-+\\r?\\n|-+END PUBLIC KEY-+\\r?\\n?)", ""); // don't use this for real projects! BASE64Decoder decoder = new BASE64Decoder(); keyBytes = decoder.decodeBuffer(pubKey); // generate public key X509EncodedKeySpec spec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); PublicKey publicKey = keyFactory.generatePublic(spec); System.out.println( String.format("Key format: %s, algorithm: %s", publicKey.getFormat(), publicKey.getAlgorithm())); } }
