Android™
Android™
Create a JWS
See more JSON Web Signatures (JWS) Examples
Demonstrates Jws.CreateJws, which creates and returns a JWS from the current payload, headers, and signing key.
Background. JWS (JSON Web Signature) integrity-protects a payload with a signature or MAC. The header
alg names the algorithm; this example uses HMAC-SHA256 (HS256) with a symmetric MAC key.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;
CkJws jws = new CkJws();
// Set the protected header for signer 0, specifying the signature algorithm (alg).
CkJsonObject header = new CkJsonObject();
header.UpdateString("alg","HS256");
success = jws.SetProtectedHeader(0,header);
if (success == false) {
Log.i(TAG, jws.lastErrorText());
return;
}
// Set the payload to be signed.
boolean bIncludeBom = false;
success = jws.SetPayload("This is the content to sign.","utf-8",bIncludeBom);
if (success == false) {
Log.i(TAG, jws.lastErrorText());
return;
}
// Provide the HMAC key (base64) for signer 0. In production, obtain the key from a secure source
// rather than hard-coding it.
String base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
success = jws.SetMacKey(0,base64Key,"base64");
if (success == false) {
Log.i(TAG, jws.lastErrorText());
return;
}
// Create the JWS from the current payload, headers, and signing key. The returned string is the
// JWS (compact serialization by default).
String jwsCompact = jws.createJws();
if (jws.get_LastMethodSuccess() == false) {
Log.i(TAG, jws.lastErrorText());
return;
}
Log.i(TAG, jwsCompact);
}
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."
}
}