I'm trying to learn how to use encryption to encrypt and decrypt messages.
I have a class called Encripta that has the methods, the encryption works perfectly.
My method to decipher encryption decrypt , returns the following log:
"V / Decrypt: android.support.v7.widget.AppCompatEditText {41766b38 VFED..CL .F ...... 32,344-688,435 # 7f0c0052 app: id / txtMessaging} "
I'm going to post my class Main and class Encripta .
If you can tell me what I'm missing, I'm waiting (I took the code here from the same stack, and this is based on the project).
Encript
package gastecnologia.com.br.ltcrypt;
import android.util.Base64;
import java.security.MessageDigest;
import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
/**
* Created by thiago.goncalves on 22/02/2016.
*/
public class Encripta {
private final Cipher cipher;
private final SecretKeySpec key;
private AlgorithmParameterSpec spec;
public static final String SEED_16_CHARACTER = "U1MjU1M0FDOUZ.Qz";
public Encripta() throws Exception {
// hash password with SHA-256 and crop the output to 128-bit for key
MessageDigest digest = MessageDigest.getInstance("SHA-256");
digest.update(SEED_16_CHARACTER.getBytes("UTF-8"));
byte[] keyBytes = new byte[32];
System.arraycopy(digest.digest(), 0, keyBytes, 0, keyBytes.length);
cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
key = new SecretKeySpec(keyBytes, "AES");
spec = getIV();
}
public AlgorithmParameterSpec getIV() {
byte[] iv = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
IvParameterSpec ivParameterSpec;
ivParameterSpec = new IvParameterSpec(iv);
return ivParameterSpec;
}
public String encrypt(String plainText) throws Exception {
cipher.init(Cipher.ENCRYPT_MODE, key, spec);
byte[] encrypted = cipher.doFinal(plainText.getBytes("UTF-8"));
String encryptedText = new String(Base64.encode(encrypted,
Base64.DEFAULT), "UTF-8");
return encryptedText;
}
public String decrypt(String cryptedText) throws Exception {
cipher.init(Cipher.DECRYPT_MODE, key, spec);
byte[] bytes = Base64.decode(cryptedText, Base64.DEFAULT);
byte[] decrypted = cipher.doFinal(bytes);
String decryptedText = new String(decrypted, "UTF-8");
return decryptedText;
}
}package gastecnologia.com.br.ltcrypt;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends AppCompatActivity {
String mensagemCriptografada;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnCodificar = (Button) findViewById(R.id.btnCodificar);
Button btnDecrifrar = (Button) findViewById(R.id.btnDecifrar);
Button btnLimpar = (Button) findViewById(R.id.btnLimpar);
Button btnCopiar = (Button) findViewById(R.id.btnCopiar);
final EditText txtMensagem = (EditText) findViewById(R.id.txtMensagem);
btnCodificar.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.v("Btn codificar", "ok");
try {
Encripta encripta = new Encripta();
String codigo = encripta.encrypt(txtMensagem.toString());
Log.v("Criptografia",codigo);
txtMensagem.setText(codigo);
mensagemCriptografada = codigo;
} catch (Exception e) {
e.printStackTrace();
}
}
});
btnDecrifrar.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.v("Btn Decifrar","ok");
try {
Encripta encripta = new Encripta();
// encripta.getIV();
String codigoDecifrado = encripta.decrypt(mensagemCriptografada.toString());
Log.v("Mmg a ser Decifrada",codigoDecifrado);
Log.v("Decifrado",codigoDecifrado);
} catch (Exception e) {
e.printStackTrace();
}
}
});
btnLimpar.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
txtMensagem.setText("");
}
});
}
} 