E4mJAvPx

1/*
2 * To change this license header, choose License Headers in Project Properties.
3 * To change this template file, choose Tools | Templates
4 * and open the template in the editor.
5 */
6package encriptadoaes;
7
8import java.io.UnsupportedEncodingException;
9import java.security.InvalidKeyException;
10import java.security.MessageDigest;
11import java.security.NoSuchAlgorithmException;
12import java.util.Arrays;
13import java.util.Base64;
14import javax.crypto.BadPaddingException;
15import javax.crypto.Cipher;
16import javax.crypto.IllegalBlockSizeException;
17import javax.crypto.NoSuchPaddingException;
18import javax.crypto.spec.SecretKeySpec;
19
20/**
21 *
22 * @author david
23 */
24public class EncriptadorAES {
25
26    /**
27     * Crea la clave de encriptacion usada internamente
28     * @param clave Clave que se usara para encriptar
29     * @return Clave de encriptacion
30     * @throws UnsupportedEncodingException
31     * @throws NoSuchAlgorithmException 
32     */
33    private SecretKeySpec crearClave(String clave) throws UnsupportedEncodingException, NoSuchAlgorithmException {
34        byte[] claveEncriptacion = clave.getBytes("UTF-8");
35        
36        MessageDigest sha = MessageDigest.getInstance("SHA-1");
37        
38        claveEncriptacion = sha.digest(claveEncriptacion);
39        claveEncriptacion = Arrays.copyOf(claveEncriptacion, 16);
40        
41        SecretKeySpec secretKey = new SecretKeySpec(claveEncriptacion, "AES");
42
43        return secretKey;
44    }
45
46    /**
47     * Aplica la encriptacion AES a la cadena de texto usando la clave indicada
48     * @param datos Cadena a encriptar
49     * @param claveSecreta Clave para encriptar
50     * @return Información encriptada
51     * @throws UnsupportedEncodingException
52     * @throws NoSuchAlgorithmException
53     * @throws InvalidKeyException
54     * @throws NoSuchPaddingException
55     * @throws IllegalBlockSizeException
56     * @throws BadPaddingException 
57     */
58    public String encriptar(String datos, String claveSecreta) throws UnsupportedEncodingException, NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException {
59        SecretKeySpec secretKey = this.crearClave(claveSecreta);
60        
61        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");        
62        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
63
64        byte[] datosEncriptar = datos.getBytes("UTF-8");
65        byte[] bytesEncriptados = cipher.doFinal(datosEncriptar);
66        String encriptado = Base64.getEncoder().encodeToString(bytesEncriptados);
67
68        return encriptado;
69    }
70
71    /**
72     * Desencripta la cadena de texto indicada usando la clave de encriptacion
73     * @param datosEncriptados Datos encriptados
74     * @param claveSecreta Clave de encriptacion
75     * @return Informacion desencriptada
76     * @throws UnsupportedEncodingException
77     * @throws NoSuchAlgorithmException
78     * @throws InvalidKeyException
79     * @throws NoSuchPaddingException
80     * @throws IllegalBlockSizeException
81     * @throws BadPaddingException 
82     */
83    public String desencriptar(String datosEncriptados, String claveSecreta) throws UnsupportedEncodingException, NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException {
84        SecretKeySpec secretKey = this.crearClave(claveSecreta);
85
86        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
87        cipher.init(Cipher.DECRYPT_MODE, secretKey);
88        
89        byte[] bytesEncriptados = Base64.getDecoder().decode(datosEncriptados);
90        byte[] datosDesencriptados = cipher.doFinal(bytesEncriptados);
91        String datos = new String(datosDesencriptados);
92        
93        return datos;
94    }
95}