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@Anass-ABEA
Created Aug 26, 2021
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import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.GCMParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;
/**
* Possible KEY_SIZE values are 128, 192 and 256
* Possible T_LEN values are 128, 120, 112, 104 and 96
*/
public class AES {
private SecretKey key;
private int KEY_SIZE = 128;
private int T_LEN = 128;
private byte[] IV;
public void init() throws Exception {
KeyGenerator generator = KeyGenerator.getInstance("AES");
generator.init(KEY_SIZE);
key = generator.generateKey();
}
public void initFromStrings(String secretKey, String IV){
key = new SecretKeySpec(decode(secretKey),"AES");
this.IV = decode(IV);
}
public String encryptOld(String message) throws Exception {
byte[] messageInBytes = message.getBytes();
Cipher encryptionCipher = Cipher.getInstance("AES/GCM/NoPadding");
encryptionCipher.init(Cipher.ENCRYPT_MODE, key);
IV = encryptionCipher.getIV();
byte[] encryptedBytes = encryptionCipher.doFinal(messageInBytes);
return encode(encryptedBytes);
}
public String encrypt(String message) throws Exception {
byte[] messageInBytes = message.getBytes();
Cipher encryptionCipher = Cipher.getInstance("AES/GCM/NoPadding");
GCMParameterSpec spec = new GCMParameterSpec(T_LEN,IV);
encryptionCipher.init(Cipher.ENCRYPT_MODE, key,spec);
byte[] encryptedBytes = encryptionCipher.doFinal(messageInBytes);
return encode(encryptedBytes);
}
public String decrypt(String encryptedMessage) throws Exception {
byte[] messageInBytes = decode(encryptedMessage);
Cipher decryptionCipher = Cipher.getInstance("AES/GCM/NoPadding");
GCMParameterSpec spec = new GCMParameterSpec(T_LEN, IV);
decryptionCipher.init(Cipher.DECRYPT_MODE, key, spec);
byte[] decryptedBytes = decryptionCipher.doFinal(messageInBytes);
return new String(decryptedBytes);
}
private String encode(byte[] data) {
return Base64.getEncoder().encodeToString(data);
}
private byte[] decode(String data) {
return Base64.getDecoder().decode(data);
}
private void exportKeys(){
System.err.println("SecretKey : "+encode(key.getEncoded()));
System.err.println("IV : "+encode(IV));
}
public static void main(String[] args) {
try {
AES aes = new AES();
aes.initFromStrings("CHuO1Fjd8YgJqTyapibFBQ==","e3IYYJC2hxe24/EO");
String encryptedMessage = aes.encrypt("TheXCoders_2");
String decryptedMessage = aes.decrypt(encryptedMessage);
System.err.println("Encrypted Message : " + encryptedMessage);
System.err.println("Decrypted Message : " + decryptedMessage);
//aes.exportKeys();
} catch (Exception ignored) {
}
}
}
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