Android™ Requires Chilkat v11.7.0+
Android™
Choose the PDF Encryption Algorithm: AES-256, AES-128 or RC4
See more PDF Protection Examples
Demonstrates the algorithmChoice option of the encrypt operation. aes-256 is the default and the one to use unless an older reader must open the file. aes-128 is for readers that predate AES-256. rc4-128 and rc4-40 are broken ciphers kept only for very old readers. Each algorithm needs a minimum PDF version, and the file header is raised to it when the PDF is saved, never lowered. A PDF saved with RC4 is written with a classic cross-reference table so that those old readers can parse it.Chilkat Android™ Downloads
// 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 requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// The PDF used in this example is available at two_page_memo.pdf
CkJsonObject json = new CkJsonObject();
CkJsonObject jsonOut = new CkJsonObject();
CkJsonObject info = new CkJsonObject();
// AES-256, the default. Saved as PDF 1.7 with Adobe extension level 8.
CkPdf pdf1 = new CkPdf();
success = pdf1.LoadFile("qa_data/pdf/two_page_memo.pdf");
if (success == false) {
Log.i(TAG, pdf1.lastErrorText());
return;
}
pdf1.put_UserPassword("user-secret");
pdf1.put_OwnerPassword("owner-secret");
json.UpdateString("algorithmChoice","aes-256");
success = pdf1.Protection("encrypt",json,jsonOut);
if (success == false) {
Log.i(TAG, pdf1.lastErrorText());
return;
}
Log.i(TAG, "aes-256 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion") + ", Adobe extension level " + String.valueOf(jsonOut.IntOf("pending.adobeExtensionLevel")));
success = pdf1.WriteFile("qa_output/memo_aes256.pdf");
if (success == false) {
Log.i(TAG, pdf1.lastErrorText());
return;
}
success = pdf1.PreLoadCheck("qa_output/memo_aes256.pdf",info);
if (success == false) {
Log.i(TAG, pdf1.lastErrorText());
return;
}
Log.i(TAG, " saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion"));
// AES-128, for readers that predate AES-256. Saved as PDF 1.6.
CkPdf pdf2 = new CkPdf();
success = pdf2.LoadFile("qa_data/pdf/two_page_memo.pdf");
if (success == false) {
Log.i(TAG, pdf2.lastErrorText());
return;
}
pdf2.put_UserPassword("user-secret");
pdf2.put_OwnerPassword("owner-secret");
json.UpdateString("algorithmChoice","aes-128");
success = pdf2.Protection("encrypt",json,jsonOut);
if (success == false) {
Log.i(TAG, pdf2.lastErrorText());
return;
}
Log.i(TAG, "aes-128 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion"));
success = pdf2.WriteFile("qa_output/memo_aes128.pdf");
if (success == false) {
Log.i(TAG, pdf2.lastErrorText());
return;
}
success = pdf2.PreLoadCheck("qa_output/memo_aes128.pdf",info);
if (success == false) {
Log.i(TAG, pdf2.lastErrorText());
return;
}
Log.i(TAG, " saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion"));
// RC4-128, a broken cipher, only for readers too old for AES. Saved as PDF 1.4.
CkPdf pdf3 = new CkPdf();
success = pdf3.LoadFile("qa_data/pdf/two_page_memo.pdf");
if (success == false) {
Log.i(TAG, pdf3.lastErrorText());
return;
}
pdf3.put_UserPassword("user-secret");
pdf3.put_OwnerPassword("owner-secret");
json.UpdateString("algorithmChoice","rc4-128");
success = pdf3.Protection("encrypt",json,jsonOut);
if (success == false) {
Log.i(TAG, pdf3.lastErrorText());
return;
}
Log.i(TAG, "rc4-128 will be saved as PDF " + jsonOut.stringOf("pending.pdfVersion"));
success = pdf3.WriteFile("qa_output/memo_rc4_128.pdf");
if (success == false) {
Log.i(TAG, pdf3.lastErrorText());
return;
}
success = pdf3.PreLoadCheck("qa_output/memo_rc4_128.pdf",info);
if (success == false) {
Log.i(TAG, pdf3.lastErrorText());
return;
}
Log.i(TAG, " saved file: " + info.stringOf("algorithm") + ", PDF " + info.stringOf("pdfVersion"));
// Sample output:
// aes-256 will be saved as PDF 1.7, Adobe extension level 8
// saved file: aes-256, PDF 1.7
// aes-128 will be saved as PDF 1.6
// saved file: aes-128, PDF 1.6
// rc4-128 will be saved as PDF 1.4
// saved file: rc4-128, PDF 1.4
}
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."
}
}