XmmVa20e

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 */
6
7
8package laborator7;
9import java.security.Key;
10import java.security.KeyPair;
11import java.security.KeyPairGenerator;
12import java.security.Security;
13import java.security.SecureRandom;
14import javax.crypto.Cipher;
15import java.security.InvalidKeyException;
16import java.security.NoSuchAlgorithmException;
17import java.security.spec.InvalidKeySpecException;
18import javax.crypto.BadPaddingException;
19import javax.crypto.IllegalBlockSizeException;
20import javax.crypto.NoSuchPaddingException;
21import javax.crypto.SecretKey;
22import javax.crypto.SecretKeyFactory;
23import javax.crypto.ShortBufferException;
24import javax.crypto.spec.PBEKeySpec;
25import javax.crypto.spec.SecretKeySpec;
26import javax.rmi.CORBA.Util;
27
28public class Laborator7 {
29
30    /**
31     * @param args the command line arguments
32     */
33    
34    public static void main(String[] args) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, ShortBufferException, IllegalBlockSizeException, BadPaddingException, InvalidKeySpecException {
35        // TODO code application logic here
36        
37        
38        //IV vector
39        byte[] iv = new byte[16];
40        SecureRandom ivspec = new SecureRandom(iv);
41        ivspec.nextBytes(iv);
42        
43       //Simetric  "AES"
44        byte[] keyBytes = new byte[16];
45        // declare secure PRNG
46        SecureRandom myPRNG = new SecureRandom();
47        // seed the key
48        myPRNG.nextBytes(keyBytes);
49        // build the key from random key bytes
50        SecretKeySpec myKey = new SecretKeySpec(keyBytes, "AES");
51        // instantiate AES object for ECB with no padding
52        Cipher myAES = Cipher.getInstance("AES/ECB/NoPadding");
53        // initialize AES objecy to encrypt mode
54        myAES.init(Cipher.ENCRYPT_MODE, myKey);
55        // initialize plaintext
56        byte[] plaintext = new byte[32];
57        
58        //initialize ciphertext
59        byte[] ciphertext = new byte[myAES.getOutputSize(plaintext.length)];
60        // update cipher with the plaintext
61        int cLength = myAES.update(plaintext, 0, plaintext.length, ciphertext,0);
62        // process remaining blocks of plaintext
63        cLength += myAES.doFinal(ciphertext, cLength);
64        // print plaintext and ciphertext
65        System.out.println("plaintext: " + javax.xml.bind.DatatypeConverter.printHexBinary(plaintext));
66        System.out.println("ciphertext: " +  javax.xml.bind.DatatypeConverter.printHexBinary(ciphertext));
67        // initialize AES for decryption
68        
69        
70        
71        
72        myAES.init(Cipher.DECRYPT_MODE, myKey);
73        // initialize a new array of bytes to place the decryption
74        byte[] dec_plaintext = new byte[32];
75        cLength = myAES.update(ciphertext, 0, ciphertext.length, dec_plaintext,0);
76        // process remaining blocks of ciphertext
77        cLength += myAES.doFinal(dec_plaintext, cLength);
78        // print the new plaintext (hopefully identical to the initial one)
79        System.out.println("decrypted: " +
80        javax.xml.bind.DatatypeConverter.printHexBinary(dec_plaintext));
81        // get a Cipher instance for RSA with PKCS1 padding
82        Cipher myRSA = Cipher.getInstance("RSA/ECB/PKCS1Padding");
83        // get an instance for the Key Generator
84        KeyPairGenerator myRSAKeyGen = KeyPairGenerator.getInstance("RSA");
85        // generate an 1024 bit key
86        KeyPair myRSAKeyPair= myRSAKeyGen.generateKeyPair();
87        // store the public and private key individually
88        Key pbKey = myRSAKeyPair.getPublic();
89        Key pvKey = myRSAKeyPair.getPrivate();
90        
91        
92        // init cipher for encryption
93        myRSA.init(Cipher.ENCRYPT_MODE, pbKey, ivspec);
94        // encrypt, as expected we encrypt a symmetric key with RSA rather than a file or some longer stream which should be encrypted with AES
95        ciphertext = myRSA.doFinal(keyBytes);
96        // init cipher for decryption
97        myRSA.init(Cipher.DECRYPT_MODE, pvKey);
98        // decrypt
99        plaintext = myRSA.doFinal(ciphertext);
100        System.out.println("plaintext: " + javax.xml.bind.DatatypeConverter.printHexBinary(plaintext));
101        System.out.println("ciphertext: " + javax.xml.bind.DatatypeConverter.printHexBinary(ciphertext));
102        System.out.println("keybytes: " + javax.xml.bind.DatatypeConverter.printHexBinary(keyBytes));
103    
104        
105      //  System.out.println("IV vector : " + javax.xml.bind.DatatypeConverter.printHexBinary(iv));
106        
107        char[] password = "short_password".toCharArray();
108        byte[] salt = new byte[16];
109        int iteration_count = 10000;
110    
111         int key_size = 128;
112        // set salt values to random
113        myPRNG.nextBytes(salt);
114
115        // initialize key factory for HMAC-SHA1 derivation
116        SecretKeyFactory keyFactory =
117        SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
118        // set key specification
119        PBEKeySpec pbekSpec = new PBEKeySpec(password, salt, iteration_count,key_size);
120        // generate the key
121        SecretKey myAESPBKey = new SecretKeySpec(
122        keyFactory.generateSecret(pbekSpec).getEncoded(), "AES");
123        // print the key
124        System.out.println("AES key: " + javax.xml.bind.DatatypeConverter.printHexBinary(myAESPBKey.getEncoded()));
125        System.out.println("IV vector : " + javax.xml.bind.DatatypeConverter.printHexBinary(iv));
126    
127    
128    }
129    
130}