Getting errors in Android Studio that I can't solve

package com.androidedsoft.aesencryptor; import android.support.v7.app.ActionBarActivity; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Button; import android.widget.EditText; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import android.util.Base64; import org.apache.commons.codec.Decoder; import org.apache.commons.codec.Encoder; public class MainActivity extends ActionBarActivity { public static SecretKey secretKey; static Cipher cipher; Button encryptbutton; String plainText; public static void main(String[] args) throws Exception { KeyGenerator keyGenerator = KeyGenerator.getInstance("AES"); keyGenerator.init(128); //key is 128 bit SecretKey secretKey = keyGenerator.generateKey(); cipher = Cipher.getInstance("AES"); //sets as AES encryption type } public void btnClick() { encryptbutton = (Button) findViewById(R.id.encryptbutton); encryptbutton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) {

Error 1

String encryptedText = encrypt(plainText, secretKey);

Continued

EditText Resultbox = (EditText) findViewById(R.id.Resultbox); Resultbox.setText(String.valueOf(encryptedText)); } }); } public static String encrypt(String plainText, SecretKey secretKey) throws Exception { byte[] plainTextByte = plainText.getBytes(); cipher.init(Cipher.ENCRYPT_MODE, secretKey); byte[] encryptedByte = cipher.doFinal(plainTextByte);

Error 2

Encoder encoder = Base64.getEncoder(); String encryptedText = encoder.encodeToString(encryptedByte);

Continued

return encryptedText; } //defines the encryption function public static String decrypt(String encryptedText, SecretKey secretKey) throws Exception {

Error 3

Decoder decoder = Base64.getDecoder();

Continued

byte[] encryptedTextByte = (byte[]) decoder.decode(encryptedText); cipher.init(Cipher.DECRYPT_MODE, secretKey); byte[] decryptedByte = cipher.doFinal(encryptedTextByte); String decryptedText = new String(decryptedByte); return decryptedText; } //defines the decryption function @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } }

At lines 51, 52, and 58 I am getting cannot resolve method errors and don't know how to solve them. At line 39 I'm getting an unhandled exception error. Anyone have any idea how to fix this? I don't know if I am just not importing something but everything I could find was included in the imports I already have.

--------------Solutions-------------

Here is a SimpleCrypto class that I am using. It's basically a combination of this thread and some small fixes I made in order to work properly.

SimpleCrypto.java

public class SimpleCrypto{
public static String encrypt(String seed, String cleartext) throws Exception
{
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}

public static String decrypt(String seed, String encrypted) throws Exception
{
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}

private static byte[] getRawKey(byte[] seed) throws Exception
{
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}

private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception
{
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}

private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception
{
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}

public static String toHex(String txt)
{
return toHex(txt.getBytes());
}

public static String fromHex(String hex)
{
return new String(toByte(hex));
}

public static byte[] toByte(String hexString)
{
int len = hexString.length() / 2;
byte[] result = new byte[len];
for (int i = 0; i < len; i++)
result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2), 16).byteValue();
return result;
}

public static String toHex(byte[] buf)
{
if (buf == null)
return "";
StringBuffer result = new StringBuffer(2 * buf.length);
for (int i = 0; i < buf.length; i++)
{
appendHex(result, buf[i]);
}
return result.toString();
}

private final static String HEX = "0123456789ABCDEF";

private static void appendHex(StringBuffer sb, byte b)
{
sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
}
}

You can use it like this:

String cryptoString = SimpleCrypto.encrypt(masterpassword, cleartext); String clearString = SimpleCrypto.decrypt(masterpassword, crypto);

Category:android Time:2017-12-01 Views:1
Tags: android

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