Java

Export a Public Key as DER into a BinData

Demonstrates the Chilkat PublicKey.GetDerBd method, which writes the public key as binary DER into a BinData. The first argument selects the representation (as for GetPem) and the second is the BinData that receives the bytes (its contents are replaced).

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: The in-memory binary export: the raw DER lands in a BinData ready to hash, transmit, or hand to another API without a temporary file. It is the BinData counterpart to the text exporters, and the first argument picks the same PKCS #1 versus SubjectPublicKeyInfo structure.

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import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.PublicKey;

public class ChilkatExample {

    public static void main(String[] args) {
        // Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
        // JWK, and other supported representations.
        PublicKey pubKey = new PublicKey();
        try {
            pubKey.loadFromFile("qa_data/public.pem");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Write the public key as binary DER into a BinData.  The 1st argument selects the representation
        // (as for GetPem) and the 2nd is the BinData that receives the bytes (its contents are replaced).
        boolean preferPkcs1 = false;
        BinData bd = new BinData();
        try {
            pubKey.getDerBd(preferPkcs1, bd);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println("Exported " + bd.getNumBytes() + " DER bytes.");
    }
}