Android™

Get an EC Key in Raw Hex Format

See more ECC Examples

Demonstrates how to get the private and public key parts of an EC (ECDSA) key in lowercase hex formmat.

Note: This example requires Chilkat v9.5.0.83 or greater.

Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

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

    // Load an EC key from some format..
    CkPrivateKey privKey = new CkPrivateKey();

    // This loads an ECDSA key from an unencrypted PEM file (no password required).
    success = privKey.LoadAnyFormatFile("qa_data/ecc/openssl_ecc_privKey.pem","");
    if (success == false) {
        Log.i(TAG, privKey.lastErrorText());
        return;
        }

    // The key type should be "ecc" to indicate an EC key.
    Log.i(TAG, "key type = " + privKey.keyType());

    // What is the size of the private key in bits?
    Log.i(TAG, "size in bits = " + String.valueOf(privKey.get_BitLength()));

    // Get the private and public EC key parts in raw hex format:
    CkStringBuilder sbPubKeyHex = new CkStringBuilder();
    String privKeyHex = privKey.getRawHex(sbPubKeyHex);

    // If the private key size in bits is 256, then we should have a 32-byte key (a 64 character hex string).
    Log.i(TAG, "private key = " + privKeyHex);

    // The public key is composed of the "x" and "y" parts, and is composed like this:  04||HEX(x)||HEX(y)
    Log.i(TAG, "public key = " + sbPubKeyHex.getAsString());

    // Sample output:
    // key type = ecc
    // size in bits = 256
    // private key = ced36f2ba3332be439f79143d69937fc52494cd38e45243c3ea05db183919f1b
    // public key = 045b4edcd501831740895f5907feabb71587076a6314d9d5141f9f8c33a478b8ce08b8dfd2a091eb6355803d7e729876c790bc0b176f2015f3bb103813753f676a

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}