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Android™

Export a Public Key as DER into a BinData

Demonstrates the Chilkat PublicKey.GetDerBd method, which writes the public key as binary DER into a BinData. The first argument selects the representation (as for GetPem) and the second is the BinData that receives the bytes (its contents are replaced).

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: The in-memory binary export: the raw DER lands in a BinData ready to hash, transmit, or hand to another API without a temporary file. It is the BinData counterpart to the text exporters, and the first argument picks the same PKCS #1 versus SubjectPublicKeyInfo structure.

Chilkat Android™ Downloads

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;

    //  Load a public key to export.  LoadFromFile inspects the content, so it accepts DER, PEM, XML,
    //  JWK, and other supported representations.
    CkPublicKey pubKey = new CkPublicKey();
    success = pubKey.LoadFromFile("qa_data/public.pem");
    if (success == false) {
        Log.i(TAG, pubKey.lastErrorText());
        return;
        }

    //  Write the public key as binary DER into a BinData.  The 1st argument selects the representation
    //  (as for GetPem) and the 2nd is the BinData that receives the bytes (its contents are replaced).
    boolean preferPkcs1 = false;
    CkBinData bd = new CkBinData();
    success = pubKey.GetDerBd(preferPkcs1,bd);
    if (success == false) {
        Log.i(TAG, pubKey.lastErrorText());
        return;
        }

    Log.i(TAG, "Exported " + String.valueOf(bd.get_NumBytes()) + " DER bytes.");

  }

  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."
  }
}