aCnHHGRc

1public String DoMAC(String passwd) throws NoSuchAlgorithmException, InvalidKeyException, IOException {
2
3		Mac mac = Mac.getInstance("HmacSHA256");
4		byte [] pass = passwd.getBytes(); 
5		SecretKey key = new SecretKeySpec(pass, "HmacSHA256"); 
6		mac.init(key);
7		return DatatypeConverter.printHexBinary(mac.doFinal());
8	}
9
10	public static void AssinaturaDigital(File filename,String password, String alias) throws Exception {
11		byte[] bFile = Files.readAllBytes(Paths.get(filename.getName()));
12		FileOutputStream fos = new FileOutputStream(filename.getName().split("\\.(?=[^\\.]+$)")[0]+".sig");
13		ObjectOutputStream oos = new ObjectOutputStream(fos);
14
15		FileInputStream fileInputStream = new FileInputStream(alias+".file");
16		KeyStore keyStore = KeyStore.getInstance("JKS");
17		keyStore.load(fileInputStream, password.toCharArray());
18		Key privateKey = keyStore.getKey(alias, password.toCharArray());
19
20		Signature s = Signature.getInstance("SHA256withRSA");
21		s.initSign((PrivateKey) privateKey);
22		s.update(bFile);
23		oos.writeObject(bFile);
24		oos.writeObject(s.sign( ));
25		fos.close();
26	}
27
28
29	public static void CifrarFile(String filename,String alias) throws Exception {
30		KeyGenerator kg = KeyGenerator.getInstance("AES");
31		kg.init(128);
32		SecretKey key = kg.generateKey();
33		Cipher c = Cipher.getInstance("AES");
34		c.init(Cipher.ENCRYPT_MODE, key);
35
36		FileInputStream fis;
37		FileOutputStream fos;
38		CipherOutputStream cos;
39		
40		fis = new FileInputStream(filename);
41		fos = new FileOutputStream(filename.split("\\.(?=[^\\.]+$)")[0]+".cif");
42
43		cos = new CipherOutputStream(fos, c);
44		byte[] b = new byte[16];  
45		int i = fis.read(b);
46		while (i != -1) {
47			cos.write(b, 0, i);
48			i = fis.read(b);
49		}
50		cos.close();
51		fos.close();
52		fis.close();
53
54		FileOutputStream kos = new FileOutputStream(filename.split("\\.(?=[^\\.]+$)")[0]+".key"); //
55		kos.write(key.getEncoded());
56		kos.close();
57
58
59	}
60
61
62	
63	public static void DecifraFile(byte[] chave,String alias,String password,String filename) throws Exception {
64
65		int i=chave.length;
66		SecretKeySpec key = new  SecretKeySpec(chave, "AES");
67		Cipher c = Cipher.getInstance("AES");
68
69		c.init(Cipher.DECRYPT_MODE, key);
70		System.out.println(filename);
71		String novonome= filename.split("/")[1];
72		FileInputStream cos = new FileInputStream(novonome.split("\\.(?=[^\\.]+$)")[0]+".cif");
73
74		CipherInputStream asduos = new CipherInputStream(cos, c);
75		String novonome1= filename.split("/")[1];
76		File file2 = new File(novonome1.split("\\.(?=[^\\.]+$)")[0]+".txt");
77		FileOutputStream fileOutputStream = new FileOutputStream(file2);
78		BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
79
80		byte[] byt = new byte[16];  
81		int size = asduos.read(chave);
82		
83		while (i != -1) {
84			bufferedOutputStream.write(chave, 0, i);
85			bufferedOutputStream.flush();
86			i = asduos.read(chave);
87		}
88		asduos.close();
89		bufferedOutputStream.close();
90	    fileOutputStream.close();
91	    cos.close();
92	    
93		
94		}
95	
96
97public static void VerificarAssinatura(File filename,String password, String alias) throws Exception {
98	String novonome = filename.getName().split("\\.(?=[^\\.]+$)")[0]+".sig";
99	FileInputStream fis = new FileInputStream(novonome);
100	ObjectInputStream ois = new ObjectInputStream(fis);
101	byte [] data = (byte []) ois.readObject( ); //não fiz verificação de erro
102	
103	byte signature[] = (byte[]) ois.readObject( ); //não fiz verificação de erro
104	
105	 
106
107    
108	FileInputStream fileInputStream = new FileInputStream(alias+".file");
109	KeyStore keyStore = KeyStore.getInstance("JKS");
110	keyStore.load(fileInputStream, password.toCharArray());
111	Key privateKey = keyStore.getKey(alias, password.toCharArray());
112    Certificate certificate = keyStore.getCertificate(alias);
113    
114	PublicKey pk = certificate.getPublicKey( );
115	
116	Signature s = Signature.getInstance("SHA256withRSA");
117	s.initVerify(pk);
118	s.update(data);
119	boolean verificado =s.verify(signature);
120	if (verificado) {
121		System.out.println("Ficheiro está valido e é seu");
122	}
123	else {
124		System.out.println("Ficheiro inválido , não é seu");
125	}
126	File fichCIF =new File(filename.getName().split("\\.(?=[^\\.]+$)")[0]+".cif");
127	File fichSIG =new File(filename.getName().split("\\.(?=[^\\.]+$)")[0]+".sig");
128	fichSIG.delete();
129	fichCIF.delete();
130	fis.close();
131	}
132	
133}