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| package test;
import java.security.AlgorithmParameters;
import java.security.SecureRandom;
import java.security.Security;
import java.security.spec.KeySpec;
import java.util.Random;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.encoders.Base64;
import org.json.JSONObject;
public class Main {
private static int Iterations = 65536;
public static void main(String[] args) throws Exception
{
/***************** Global *******************/
Security.addProvider(new BouncyCastleProvider());
String password = "password";
/***************** Encrypter ****************/
String texte = "texte de la mort qui tue";
String json = AesEncrypt(texte, password);
System.out.println(json);
/***************** Decrypter ****************/
String texte_decrypted = AesDecrypt(json, password);
System.out.println(texte_decrypted);
}
public static String AesEncrypt(String texte, String password) throws Exception
{
/* Générer le salt */
Random r = new SecureRandom();
byte[] st_byte = new byte[32];
r.nextBytes(st_byte);
/* Générer la clé */
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
KeySpec spec = new PBEKeySpec(password.toCharArray(), st_byte, Iterations, 256);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
/* Crypter le texte */
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
cipher.init(Cipher.ENCRYPT_MODE, secret);
AlgorithmParameters params = cipher.getParameters();
byte[] iv_byte = params.getParameterSpec(IvParameterSpec.class).getIV();
byte[] ct_byte = cipher.doFinal(texte.getBytes());
/* Convertir les données */
String st = BytesToHex(st_byte);
String iv = BytesToHex(iv_byte);
String ct = new String(Base64.encode(ct_byte));
/* Ecrire les données */
JSONObject json = new JSONObject();
json.put( "st", st);
json.put( "iv", iv);
json.put( "ct", ct);
String json_texte = json.toString();
return new String(Base64.encode(json_texte.getBytes()));
}
public static String AesDecrypt(String json_texte_64, String password) throws Exception
{
String json_texte = new String(Base64.decode(json_texte_64.getBytes()));
JSONObject json = new JSONObject(json_texte);
/* Récupérer les données */
String ct = (String) json.get("ct");
String iv = (String) json.get("iv");
String st = (String) json.get("st");
/* Convertir les données */
byte[] ct_byte = Base64.decode(ct.getBytes());
byte[] iv_byte = HexToBytes(iv);
byte[] st_byte = HexToBytes(st);
/* Générer la clé */
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
KeySpec spec = new PBEKeySpec(password.toCharArray(), st_byte, Iterations, 256);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
/* Decrypter le texte */
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
cipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(iv_byte));
byte[] texte_byte = cipher.doFinal(ct_byte);
return new String(texte_byte);
}
private static String BytesToHex(byte[] data)
{
StringBuilder buf = new StringBuilder();
for (byte b : data)
{
int halfbyte = (b >>> 4) & 0x0F;
int two_halfs = 0;
do
{
buf.append((0 <= halfbyte) && (halfbyte <= 9) ? (char) ('0' + halfbyte) : (char) ('a' + (halfbyte - 10)));
halfbyte = b & 0x0F;
} while (two_halfs++ < 1);
}
return buf.toString();
}
public static byte[] HexToBytes (String s)
{
String s2;
byte[] b = new byte[s.length() / 2];
int i;
for (i = 0; i < s.length() / 2; i++)
{
s2 = s.substring(i * 2, i * 2 + 2);
b[i] = (byte)(Integer.parseInt(s2, 16) & 0xff);
}
return b;
}
} |
