Java Requires Chilkat v11.0.0+

Get EC Public Key from EC Private Key

See more ECC Examples

Demonstrates how to get an EC public key from an EC private key. Chilkat2 Java

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

public class ChilkatExample {

    public static void main(String[] args) {
        // We have an ECC private key...
        // The contents of the private key PEM file look like this:

        //     -----BEGIN PRIVATE KEY-----
        //     MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQg3J8q/24D1sEKGdP9
        //     72MGYElLGpw/a56Y3t6pfON3uhShRANCAATlSmoizyhAwoYZAOuFBATl07/1RR54
        //     a1Dzfm16grxJe666AGKR+bSs24hk7TEpaeCTvT8YOOM3l+xKFg7zq6Q9
        //     -----END PRIVATE KEY-----

        PrivateKey privKey = new PrivateKey();
        try {
            privKey.loadPemFile("qa_data/ecc/secp256r1-key-pkcs8.pem");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Get the public key.
        PublicKey pubKey = new PublicKey();
        privKey.toPublicKey(pubKey);

        // Save the public key to a PEM file.
        try {
            pubKey.savePemFile(false, "qa_data/ecc/secp256r1-pubkey.pem");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // The contents of the ECC public key PEM file look like this:

        //     -----BEGIN PUBLIC KEY-----
        //     MIIBSzCCAQMGByqGSM49AgEwgfcCAQEwLAYHKoZIzj0BAQIhAP////8AAAABAAAA
        //     AAAAAAAAAAAA////////////////MFsEIP////8AAAABAAAAAAAAAAAAAAAA////
        //     ///////////8BCBaxjXYqjqT57PrvVV2mIa8ZR0GsMxTsPY7zjw+J9JgSwMVAMSd
        //     NgiG5wSTamZ44ROdJreBn36QBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt6zOg9KE5
        //     RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
        //     //////////+85vqtpxeehPO5ysL8YyVRAgEBA0IABOVKaiLPKEDChhkA64UEBOXT
        //     v/VFHnhrUPN+bXqCvEl7rroAYpH5tKzbiGTtMSlp4JO9Pxg44zeX7EoWDvOrpD0=
        //     -----END PUBLIC KEY-----

        System.out.println("Success.");
    }
}