Showing posts with label aes. Show all posts
Showing posts with label aes. Show all posts

Thursday, June 23, 2016

AES Encryption Decryption in Android



This is the easiest way of implementing AES Encryption and Decryption in Android.



import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
 import javax.crypto.spec.SecretKeySpec;

public class AESEncryptionDecryption {

private static final byte[] keyValue =
        new byte[]{'c', 'o', 'd', 'i', 'n', 'g', 'a', 'f', 'f', 'a', 'i', 'r', 's', 'c', 'o', 'm'};


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

public static String decrypt(String encrypted)
        throws Exception {

    byte[] enc = toByte(encrypted);
    byte[] result = decrypt(enc);
    return new String(result);
}

private static byte[] getRawKey() throws Exception {
    SecretKey key = new SecretKeySpec(keyValue, "AES");
    byte[] raw = key.getEncoded();
    return raw;
}

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

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));
}
String encrypted = "";
try {
    encrypted = AESEncryptionDecryption.encrypt(plain_text);
    Log.d(Constants.firebase_app, "encrypted:" + encrypted);
} catch (Exception e) {
    e.printStackTrace();
}
*********************************************************************
String decrypted = "";
try {
    decrypted = AESEncryptionDecryption.decrypt(encrypted);
    Log.d(Constants.firebase_app, "decrypted:" + decrypted);
} catch (Exception e) {
    e.printStackTrace();
}

Author:
Hammad Tariq
Android Developer

Kotlin Android MVP Dagger 2 Retrofit Tutorial

http://developine.com/building-android-mvp-app-in-kotlin-using-dagger-retrofit/