I am making an encryption/decryption module for my app. I followed This Tutorial
It is not giving any error and also not showing the output.
Logfile
07-23 07:29:06.480: W/System.err(795): javax.crypto.BadPaddingException: pad block corrupted
07-23 07:29:06.629: W/System.err(795): at com.android.org.bouncycastle.jcajce.provider.symmetric.util.BaseBlockCipher.engineDoFinal(BaseBlockCipher.java:710)
07-23 07:29:06.629: W/System.err(795): at javax.crypto.Cipher.doFinal(Cipher.java:1111)
07-23 07:29:06.660: W/System.err(795): at com.example.generatesha384.AESHelper.decrypt(AESHelper.java:52)
07-23 07:29:06.690: W/System.err(795): at com.example.generatesha384.AESHelper.decrypt(AESHelper.java:25)
07-23 07:29:06.690: W/System.err(795): at com.example.generatesha384.MainActivity.onCreate(MainActivity.java:24)
07-23 07:29:06.700: W/System.err(795): at android.app.Activity.performCreate(Activity.java:5133)
07-23 07:29:06.730: W/System.err(795): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
07-23 07:29:06.730: W/System.err(795): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
07-23 07:29:06.770: W/System.err(795): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
07-23 07:29:06.770: W/System.err(795): at android.app.ActivityThread.access$600(ActivityThread.java:141)
07-23 07:29:06.770: W/System.err(795): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
07-23 07:29:06.800: W/System.err(795): at android.os.Handler.dispatchMessage(Handler.java:99)
07-23 07:29:06.800: W/System.err(795): at android.os.Looper.loop(Looper.java:137)
07-23 07:29:06.840: W/System.err(795): at android.app.ActivityThread.main(ActivityThread.java:5103)
07-23 07:29:06.840: W/System.err(795): at java.lang.reflect.Method.invokeNative(Native Method)
07-23 07:29:06.872: W/System.err(795): at java.lang.reflect.Method.invoke(Method.java:525)
07-23 07:29:06.880: W/System.err(795): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
07-23 07:29:06.910: W/System.err(795): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
07-23 07:29:06.910: W/System.err(795): at dalvik.system.NativeStart.main(Native Method)
MainActivity.Java
String seedValue = "This Is MySecure";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView text = (TextView)findViewById(R.id.result);
String normalText = "VIJAY";
String normalTextEnc;
try {
normalTextEnc = AESHelper.encrypt(seedValue, normalText);
String normalTextDec = AESHelper.decrypt(seedValue, normalTextEnc);
String textResult = "Normal Text ::" + normalText
+ " \n Encrypted Value :: " + normalTextEnc
+ " \n Decrypted value :: " + normalTextDec;
text.setText(textResult);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
AESHelper.Java
public class AESHelper {
public static String encrypt(String seed, String cleartext)
throws Exception {
byte[] rawKey = getRawKey(seed.getBytes("UTF-8"));
byte[] result = encrypt(rawKey, cleartext.getBytes("UTF-8"));
return toHex(result);
}
public static String decrypt(String seed, String encrypted)
throws Exception {
byte[] rawKey = getRawKey(seed.getBytes("UTF-8"));
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);
Log.d("DEC", "Decrypted: " + decrypted);
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));
}
}
AESHelper.java:52
byte[] decrypted = cipher.doFinal(encrypted);
and AESHelper.java:25
byte[] result = decrypt(rawKey, enc);
