(Android™) Sign String to create a CAdES-T Signature, using HTTP Proxy to Access Timestamp Server

This example will sign a string to create a CAdEST-T signature. It will use an HTTP proxy to access the timestamp server.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// 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);

    CkCrypt2 crypt = new CkCrypt2();

    CkCert cert = new CkCert();
    cert.put_SmartCardPin("123456");
    boolean success = cert.LoadFromSmartcard("");
    if (success != true) {
        Log.i(TAG, cert.lastErrorText());
        return;
        }

    success = crypt.SetSigningCert(cert);

    // Use SHA-256 rather than the default of SHA-1
    crypt.put_HashAlgorithm("sha256");

    // Create JSON that tells Chilkat what signing attributes to include:
    CkJsonObject attrs = new CkJsonObject();
    attrs.UpdateBool("contentType",true);
    attrs.UpdateBool("signingTime",true);
    attrs.UpdateBool("messageDigest",true);
    attrs.UpdateBool("signingCertificateV2",true);

    // A CAdES-T signature is one that includes a timestampToken created by an online TSA (time stamping authority).
    // We must include the TSA's URL, as well as a few options to indicate what is desired.
    // Except for the TSA URL, the options shown here are typically what you would need.
    attrs.UpdateBool("timestampToken.enabled",true);
    attrs.UpdateString("timestampToken.tsaUrl","https://freetsa.org/tsr");
    attrs.UpdateBool("timestampToken.addNonce",false);
    attrs.UpdateBool("timestampToken.requestTsaCert",true);
    attrs.UpdateString("timestampToken.hashAlg","sha256");

    crypt.put_SigningAttributes(attrs.emit());

    String strToSign = "Hello World!";

    CkBinData bd = new CkBinData();
    bd.AppendString(strToSign,"utf-8");

    // -------------------------------------------------------------------------
    // The purpose of this example is to show how an HTTP object with custom
    // settings can be used to access the Internet when signing.
    // Access to the Internet is needed to communicate with the timestamp server.
    CkHttp http = new CkHttp();
    // This can be a domain name, hostname, or IP address.
    http.put_ProxyDomain("172.16.16.56");
    http.put_ProxyPort(808);
    http.put_ProxyLogin("myProxyLogin");
    http.put_ProxyPassword("myProxyPassword");
    crypt.SetTsaHttpObj(http);
    // -------------------------------------------------------------------------

    // This creates the CAdES-T signature.  During the signature creation, it
    // communicates with the TSA to get a timestampToken.
    // The contents of bd are signed and replaced with the CAdES-T signature (which embeds the original content).
    success = crypt.OpaqueSignBd(bd);
    if (success != true) {
        Log.i(TAG, crypt.lastErrorText());
        return;
        }

    // Get the signature in base64 format:
    Log.i(TAG, bd.getEncoded("base64_mime"));

    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."
  }
}