Java Requires Chilkat v10.1.3+

Yubikey RSA Encrypt/Decrypt

See more RSA Examples

Demonstrates how to do RSA decryption using a private key stored on a Yubikey (or other USB token or smartcard).

Note: RSA encryption uses the public key, which is freely exportable and does not need to occur on the token/smartcard.

Chilkat2 Java

import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Rsa;

public class ChilkatExample {

    public static void main(String[] args) {
        // This example assumes you have a certificate with private key on the Yubikey token.
        // When doing simple RSA encryption/decryption, we don't actually need the certificate,
        // but we'll be using the private key associated with the certificate.
        //
        // The sensitive/secret material that needs to be kept private is the private key.
        // The certificate itself and the public key can be freely shared.
        //

        // We're going to encrypt and decrypt 32-bytes of data.
        BinData bd = new BinData();
        bd.appendEncoded("000102030405060708090A0B0C0D0E0F", "hex");
        bd.appendEncoded("000102030405060708090A0B0C0D0E0F", "hex");

        // Let's get the desired cert.
        // For this example, a self-signed certificate with a 2048-bit RSA key was generated in slot 9A.
        Cert cert = new Cert();

        // Force Chilkat to use PKCS11 over ScMinidriver (if on Windows) and Apple Keychain (if on MacOS)
        cert.setUncommonOptions("NoScMinidriver,NoAppleKeychain");

        cert.setSmartCardPin("123456");

        try {
            cert.loadFromSmartcard("cn=chilkat_test_2048");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // RSA encrypt using the public key.
        Rsa rsa = new Rsa();

        // Provide the RSA object with the certificate on the Yubkey.
        try {
            rsa.setX509Cert(cert, true);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // RSA encrypt using the public key.
        boolean usePrivateKey = false;
        try {
            rsa.encryptBd(bd, usePrivateKey);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("RSA Encrypted Output in Hex:");
        System.out.println(bd.getEncoded("hex"));

        // Now let's decrypt, using the private key on the Yubikey.
        usePrivateKey = true;
        try {
            rsa.decryptBd(bd, usePrivateKey);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("RSA Decrypted Output in Hex:");
        System.out.println(bd.getEncoded("hex"));
    }
}