(Java) Create PKCS1 RSA Signature with PEM Private Key

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Note: This example requires Chilkat v11.0.0 or greater.

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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;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkPrivateKey pkey = new CkPrivateKey();

    // Load the private key from an RSA PEM file:
    success = pkey.LoadPemFile("pvkey2_rsa.pem");
    if (success == false) {
        System.out.println(pkey.lastErrorText());
        return;
        }

    CkRsa rsa = new CkRsa();

    // Import the private key into the RSA object:
    success = rsa.UsePrivateKey(pkey);
    if (success == false) {
        System.out.println(rsa.lastErrorText());
        return;
        }

    // Get the signature as hex.
    rsa.put_EncodingMode("hex");

    String strData = "This is the string to be signed.";

    // Sign the string using the sha-1 hash algorithm.
    // Other valid choices are "md2", "md5", "sha256",
    // "sha384", and "sha512".
    String hexSig = rsa.signStringENC(strData,"sha-1");

    System.out.println(hexSig);

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