Java

Load a Private Key from a JWK

Demonstrates the Chilkat PrivateKey.LoadJwk method, which loads a private key from JWK (JSON Web Key) JSON. The only argument is the JWK JSON string. Supported key types are RSA, EC, and Ed25519 (kty=OKP).

Background: JWK is the JSON key format used throughout modern web security — JWT signing, OAuth, OpenID Connect — so this loader is what you use to consume a key from a JWK Set or an identity provider. A private JWK includes the private parameters (d and, for RSA, the CRT values); a public-only JWK omits them. As JSON in the clear, a private JWK must be handled as sensitive material.

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Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  Demonstrates the PrivateKey.LoadJwk method, which loads a private key from JWK (JSON Web Key)
    //  JSON.  The only argument is the JWK JSON string.  Supported key types are RSA, EC, and
    //  Ed25519 (kty=OKP).

    CkPrivateKey privKey = new CkPrivateKey();

    //  A private JWK.  For a real key, "d" (and the other private parameters) would be present.
    String jwk = "{\"kty\":\"EC\",\"crv\":\"P-256\",\"x\":\"...\",\"y\":\"...\",\"d\":\"...\"}";

    success = privKey.LoadJwk(jwk);
    if (success == false) {
        System.out.println(privKey.lastErrorText());
        return;
        }

    System.out.println("Loaded a " + privKey.keyType() + " private key.");
  }
}