Android™

Duplicate openssl pkey -in private.pem -pubout -out pubkey.pem

See more OpenSSL Examples

How to output the public part of a private key: Demonstrates how to duplicate this OpenSSL command:

openssl pkey -in private.pem -pubout -out pubkey.pem

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;

    CkPrivateKey pkey = new CkPrivateKey();

    // Load the private key from an PEM file:
    success = pkey.LoadPemFile("private.pem");
    if (success == false) {
        Log.i(TAG, pkey.lastErrorText());
        return;
        }

    CkPublicKey pubKey = new CkPublicKey();
    pkey.ToPublicKey(pubKey);

    success = pubKey.SavePemFile(false,"pubKey.pem");
    if (success != true) {
        Log.i(TAG, pubKey.lastErrorText());

        return;
        }

    Log.i(TAG, "Success.");

  }

  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."
  }
}