vVAWJrC4

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 aes;
7
8import java.io.BufferedReader;
9import java.io.FileInputStream;
10import java.io.FileNotFoundException;
11import java.io.FileOutputStream;
12import java.io.IOException;
13import java.io.RandomAccessFile;
14import java.nio.charset.StandardCharsets;
15import java.security.InvalidKeyException;
16import java.security.NoSuchAlgorithmException;
17import java.security.Provider;
18import java.security.SecureRandom;
19import java.security.Security;
20import java.security.spec.InvalidKeySpecException;
21import java.util.Arrays;
22import java.util.Scanner;
23import java.util.logging.Level;
24import java.util.logging.Logger;
25import javax.crypto.BadPaddingException;
26import javax.crypto.Cipher;
27import javax.crypto.IllegalBlockSizeException;
28import javax.crypto.KeyGenerator;
29import javax.crypto.NoSuchPaddingException;
30import javax.crypto.SecretKey;
31import javax.crypto.SecretKeyFactory;
32import javax.crypto.spec.SecretKeySpec;
33
34/**
35 *
36 * @author shoke
37 */
38public class CifradoAES {
39
40    
41    private final static String ALGORITMO = "AES/ECB/PKCS5Padding";
42    private final static String FICHERO = "fichero.cifrado";
43    
44    /**
45     * @param args the command line arguments
46     */
47    public static void main(String[] args) {
48        // TODO code application logic here
49        TextoRandom tr=null;
50        Scanner scn =  new Scanner(System.in);
51        boolean encript = false;
52        String usuario;
53        String contrasena;
54        FileInputStream fe;
55        FileOutputStream fs;
56        String textoDescifrado;
57        
58        if (args.length!=1){
59            System.err.println("Debe recibir 1 parámetro, debe indicar \"-c\" para cifrar y \"-d\" para descifrar.");
60            return;
61        }
62                    
63        switch (args[0]) {
64            case "-c":
65                encript = true;
66                tr = new TextoRandom();                
67                break;
68            case "-d":
69                break;
70            default:
71                System.err.println("Parámetro incorrecto debe indicar \"-c\" para cifrar y \"-d\" para descifrar.");
72                return;
73        }
74        
75        
76        //System.out.println(tr.getTexto());
77        
78        System.out.println("Introduzca el nombre de usuario: ");
79        usuario = scn.nextLine();
80        
81        System.out.println("Introduzca la contraseña");
82        contrasena = scn.nextLine();
83        
84        Provider[] prov = Security.getProviders();
85        System.err.println("");
86        
87        try{
88            Cipher cipher = Cipher.getInstance(ALGORITMO);
89            //SecretKeyFactory skf = SecretKeyFactory.getInstance("AES");
90            //KeyGenerator kg = KeyGenerator.//KeyGenerator.getInstance("AES");
91            //kg.init(128);
92            SecureRandom sr = new SecureRandom();
93            sr.setSeed((usuario+contrasena).getBytes());
94            
95            SecretKeySpec sks = new SecretKeySpec(sr.generateSeed(16),"AES");
96            
97            SecretKey secretKey = sks;
98          
99            
100            if (encript){
101                cipher.init(Cipher.ENCRYPT_MODE, secretKey);
102            }else{
103                cipher.init(Cipher.DECRYPT_MODE, secretKey);
104            }
105            
106            
107            
108            //byte[] buffer = new byte[1024];
109            byte[] bloque_cifrado=null;
110            byte[] bloque_descifrado = null;
111            
112            if (encript){
113                bloque_cifrado = cipher.doFinal(tr.getTexto().getBytes());
114                //textoCifrado= Arrays.toString(bloque_cifrado);
115                try {
116                    fs = new FileOutputStream(FICHERO);
117                    fs.write(bloque_cifrado);
118                } catch (FileNotFoundException ex) {
119                    ex.printStackTrace(System.out);
120                } catch (IOException ex) {
121                     ex.printStackTrace(System.out);
122                }
123                //System.out.println(textoCifrado);
124            }else{
125                try{
126                    textoDescifrado="";
127                    bloque_cifrado = new byte[1024];
128                    byte[] texto_cifrado = new byte[0];
129                    fe = new FileInputStream(FICHERO);
130                    int bytesLeidos = fe.read(bloque_cifrado,0,1024);
131                    while (bytesLeidos != -1){
132                        //texto_cifrado = Arrays.copyOf(texto_cifrado, texto_cifrado.length+bytesLeidos);
133                        bloque_descifrado = cipher.update(bloque_cifrado, 0, bytesLeidos);
134                        //texto_cifrado = Arrays.copyOfRange(bloque_cifrado, 0, bytesLeidos);
135                        textoDescifrado += (new String(bloque_cifrado));
136                        bytesLeidos = fe.read(bloque_cifrado,0,1024);
137                    }
138                    //bloque_descifrado = cipher.doFinal(texto_cifrado);
139                    //textoDescifrado = new String(bloque_descifrado);
140                    System.out.println(textoDescifrado);
141                    
142                    
143                } catch (FileNotFoundException ex) {
144                     ex.printStackTrace(System.out);
145                } catch (IOException ex) {
146                     ex.printStackTrace(System.out);
147                }
148            }
149        } catch (NoSuchAlgorithmException|NoSuchPaddingException|InvalidKeyException | IllegalBlockSizeException | BadPaddingException ex) {
150            ex.printStackTrace(System.out);
151        }
152        
153        
154        
155        
156        
157    }
158    
159}
160
161final class TextoRandom {
162    private final String texto;
163
164    public TextoRandom() {
165        texto = generaTexto();
166    }
167    
168    public String getTexto(){
169        return this.texto;
170    }
171
172    public String generaTexto(){
173        String textoGen;
174        String patron = "ABCDEFGHIIJKLMNÑOPQRSTUVWXYZabcdefghijklmnñopqrstuvwxyz0123456789";
175        char[] cadena = new char[(int)(Math.random()*(100-50)+1)+50];
176        
177        for (int i= 0;i<cadena.length;i++){
178            cadena[i]=patron.charAt((int)(Math.random()*(patron.length())));
179        }
180        textoGen = String.valueOf(cadena);
181        return textoGen;
182    }    
183}