EFV1K5Gs

1package mkri;
2
3import java.math.BigInteger;
4import java.security.InvalidKeyException;
5import java.security.KeyFactory;
6import java.security.KeyPair;
7import java.security.KeyPairGenerator;
8import java.security.KeyStore.PrivateKeyEntry;
9import java.security.MessageDigest;
10import java.security.NoSuchAlgorithmException;
11import java.security.PrivateKey;
12import java.security.Provider;
13import java.security.PublicKey;
14import java.security.SecureRandom;
15import java.security.Signature;
16import java.security.SignatureException;
17import java.security.spec.InvalidKeySpecException;
18import java.security.spec.KeySpec;
19import java.security.spec.X509EncodedKeySpec;
20import java.util.Base64;
21import java.util.Base64.*;
22
23import javax.crypto.Cipher;
24import javax.crypto.KeyAgreement;
25import javax.crypto.KeyGenerator;
26import javax.crypto.NoSuchPaddingException;
27import javax.crypto.SecretKey;
28import javax.crypto.interfaces.DHPublicKey;
29import javax.crypto.spec.DHParameterSpec;
30import javax.crypto.spec.DHPublicKeySpec;
31import javax.crypto.spec.SecretKeySpec;
32
33public class ProtocolSec {
34
35	private Signature sign;
36	private KeyPair keyPair;
37	
38	private KeyAgreement aKeyAgree;
39	private byte[] pass;
40	
41	private Decoder dec = Base64.getDecoder();
42	private Encoder enc = Base64.getEncoder();
43
44	
45	/**
46	 * Generuje RSA
47	 * @throws NoSuchAlgorithmException
48	 * @throws InvalidKeyException
49	 */
50	public void genRSA() throws NoSuchAlgorithmException, InvalidKeyException{
51		
52		//--------------- Generovani a inicializace RSA algoritmu pro podpis, verze 2048 b, SHA512----
53		
54		
55		KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
56		keyGen.initialize(2048, new SecureRandom());
57		
58		keyPair = keyGen.generateKeyPair();
59		
60		sign = Signature.getInstance("SHA512withRSA");
61		
62		sign.initSign(keyPair.getPrivate());
63
64		
65		//---------------------------------------------
66	}
67	
68	public String getPublicKey(){
69		
70		return enc.encodeToString(keyPair.getPublic().getEncoded());
71	}
72	
73	/**
74	 * Podepisuje data
75	 * Vstup i vystup kodovan v BASE64!
76	 * @param data
77	 * @return
78	 * @throws SignatureException
79	 */
80	public String sign(String data) throws SignatureException{
81		
82		//--------------- RSA podepsani, stup: data----
83		sign.update(dec.decode(data));
84		byte[] signature = sign.sign(); 
85		//---------------------------------------------
86		return enc.encodeToString(signature);
87	}
88	
89	/**
90	 * generovani Diffie Hellman
91	 * Vraci verejny klic v BASE64!
92	 */
93	public String genDH() throws Exception{
94		
95		byte[] pubA = null;
96		//--------------- Diffie helman, inicializace a vraceni verejneho klice----
97		KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DH");
98		aKeyAgree = KeyAgreement.getInstance("DH");
99		KeyPair aPair = keyGen.generateKeyPair();
100		
101		aKeyAgree.init(aPair.getPrivate());
102		
103		pubA = aPair.getPublic().getEncoded();
104		
105	    //-------------------------------------------------------------------------
106	   return enc.encodeToString(pubA);
107	}
108	
109	/**
110	 * inicializuje algoritmus DH klicem PK protistrany, 
111	 * vypocte sdilene tajemstvi
112	 * vzpocte hash a vrati jej
113	 * Vstup kodovan BASE64!
114	 * @param pk
115	 * @throws Exception
116	 */
117	public void procDH(String pk) throws Exception {
118		
119		
120		byte[] bpk = dec.decode(pk.getBytes());
121		//--------------- Diffie Hellman , hash SHA1 -----------------------
122		
123		PublicKey publicKey = KeyFactory.getInstance("DH").generatePublic(new X509EncodedKeySpec(bpk));
124		aKeyAgree.doPhase(publicKey, true);
125		MessageDigest hash = MessageDigest.getInstance("SHA1"); 
126		pass = hash.digest(hash.digest(aKeyAgree.generateSecret()));
127		//Hash ulozit do pass - pouziva se na sifrovani
128	
129		//-------------------------------------------------------------------
130	}
131	
132	/**
133	 * Sifrování, vstup není kódován BASE64!
134	 * Výstup kódován BASE64!
135	 * @param data
136	 * @return
137	 * @throws Exception
138	 */
139	public String encrypt(String data) throws Exception{
140		
141		byte[] encAes = null;
142		
143		//KeyGenerator kg = KeyGenerator.getInstance("AES");
144		//kg.init(128);
145		//SecretKey key = kg.generateKey();
146		
147		String passw = "pass";
148		byte[] key = passw.getBytes();
149		
150		SecretKeySpec sks = new SecretKeySpec(key, "AES");
151		
152		//--------------- inicializace, sifrovani AES-128, mod ECB, padding PKCS5Padding----
153		Cipher a1 = Cipher.getInstance("AES/ECB/PKCS5Padding");
154		
155		a1.init(Cipher.ENCRYPT_MODE, sks);
156		
157		encAes = a1.doFinal(data.getBytes());
158		//-------------------------------------------------------------------
159		return enc.encodeToString(encAes);
160	}
161	
162	/**
163	 * Desifrování, vstup je kódován BASE64!
164	 * Výstup kódován BASE64!
165	 * @param data
166	 * @return
167	 * @throws Exception
168	 */
169	public String decrypt(String data) throws Exception{
170		
171		byte[] decAes = null;
172		
173		String passww = "pass";
174		byte[] key = passww.getBytes();
175		
176		SecretKeySpec sks1 = new SecretKeySpec(key, "AES");
177		//--------------- inicializace, desifrovani AES-128, mod ECB, padding PKCS5Padding---
178		Cipher a2 = Cipher.getInstance("AES/ECB/PKCS5Padding");
179		
180		
181		
182		a2.init(Cipher.DECRYPT_MODE, sks1);
183		decAes = a2.doFinal(dec.decode(data));
184		
185		//-------------------------------------------------------------------
186		return new String(decAes);
187	}
188
189
190
191}