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I'm trying to use encryption tools flexiprovider in my android app by using the example provided for ECIES. When I run the code in my local machine Enc/Dec work without any problem. But when I'm trying to run it as an android app using the android studio, the decryption doesn't work.

The Main Activity.java

 public void onClick12 (View view) {
        ExampleECIES exampleECIES=new ExampleECIES();
        try {
            exampleECIES.main(null);
        } catch (Exception e) {
            Log.e("main()",e.getMessage());

        }
    }

Encryption scheme:

package com.example.enctest3;
import android.Manifest;
import android.support.v4.app.ActivityCompat;
import android.util.Log;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;

import de.flexiprovider.common.exceptions.ECException;
import de.flexiprovider.common.ies.IESParameterSpec;
import de.flexiprovider.core.FlexiCoreProvider;
import de.flexiprovider.ec.FlexiECProvider;
import de.flexiprovider.ec.parameters.CurveParams;
import de.flexiprovider.ec.parameters.CurveRegistry.BrainpoolP160r1;

public class ExampleECIES {

public static void main(String[] args) throws Exception {

    Security.addProvider(new FlexiCoreProvider());
    Security.addProvider(new FlexiECProvider());

    KeyPairGenerator kpg = KeyPairGenerator.getInstance("ECIES", "FlexiEC");

    CurveParams ecParams = new BrainpoolP160r1();

    kpg.initialize(ecParams, new SecureRandom());
    KeyPair keyPair = kpg.generateKeyPair();
    PublicKey pubKey = keyPair.getPublic();
    PrivateKey privKey = keyPair.getPrivate();

    // Encrypt

    Cipher cipher = Cipher.getInstance("ECIES", "FlexiEC");

    IESParameterSpec iesParams = new IESParameterSpec("AES128_CBC",
            "HmacSHA1", null, null);

    cipher.init(Cipher.ENCRYPT_MODE, pubKey, iesParams);
    String cleartextFile =     "/storage/emulated/0/Android/data/enctest3/files/cleartext.txt";
    String ciphertextFile = "/storage/emulated/0/Android/data/enctest3/files/ciphertextECIES.txt";
    byte[] block = new byte[64];
    FileInputStream fis = new FileInputStream(cleartextFile);
    FileOutputStream fos = new FileOutputStream(ciphertextFile);
    CipherOutputStream cos = new CipherOutputStream(fos, cipher);
    int i;
    while ((i = fis.read(block)) != -1) {
        cos.write(block, 0, i);
    }
    cos.close();
    fos.close();
    fis.close();
    // Decrypt

    String cleartextAgainFile = "/storage/emulated/0/Android/data/enctest3/files/cleartextAgainECIES.txt";

    cipher.init(Cipher.DECRYPT_MODE, privKey, iesParams);
    fis = new FileInputStream(ciphertextFile);

    CipherInputStream cis = new CipherInputStream(fis, cipher);
    fos = new FileOutputStream(cleartextAgainFile);
    int x=cis.available();
    Log.e("available()",Integer.toString(x));
    while ((i= cis.read(block)) != -1) {
        fos.write(block, 0, i);
    }

    fos.close();
}

}

And here is the log:

 E/available(): 0
 E/main(): src.length=17 srcPos=0 dst.length=0 dstPos=0 length=17

The post here that is similar to my problem did not help.

Majid
  • 23
  • 5

1 Answers1

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I tried running the app on another machine with a virtual device and it worked without any problem.

Majid
  • 23
  • 5