Mega Code Archive
AES Encryption
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//package edu.gmu.tec.scout.utilities;
import java.security.MessageDigest;
import javax.crypto.*;
import javax.crypto.spec.*;
public class Encryption {
private SecretKeySpec skeySpec;
private Cipher cipher;
public Encryption(byte [] keyraw) throws Exception{
if(keyraw == null){
byte[] bytesOfMessage = "".getBytes("UTF-8");
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] bytes = md.digest(bytesOfMessage);
skeySpec = new SecretKeySpec(bytes, "AES");
cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
}
else{
skeySpec = new SecretKeySpec(keyraw, "AES");
cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
}
}
public Encryption(String passphrase) throws Exception{
byte[] bytesOfMessage = passphrase.getBytes("UTF-8");
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] thedigest = md.digest(bytesOfMessage);
skeySpec = new SecretKeySpec(thedigest, "AES");
cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
}
public Encryption() throws Exception{
byte[] bytesOfMessage = "".getBytes("UTF-8");
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] thedigest = md.digest(bytesOfMessage);
skeySpec = new SecretKeySpec(thedigest, "AES");
skeySpec = new SecretKeySpec(new byte[16], "AES");
cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
}
public byte[] encrypt (byte[] plaintext) throws Exception{
//returns byte array encrypted with key
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] ciphertext = cipher.doFinal(plaintext);
return ciphertext;
}
public byte[] decrypt (byte[] ciphertext) throws Exception{
//returns byte array decrypted with key
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] plaintext = cipher.doFinal(ciphertext);
return plaintext;
}
public static void main(String[] args) throws Exception {
String message="This is just an example";
Encryption encrypter = new Encryption(new byte[16]);
byte[] encrypted = encrypter.encrypt(message.getBytes("UTF-8"));
byte[] decrypted = encrypter.decrypt(encrypted);
System.out.println(new String (decrypted, "UTF-8"));
}
}
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