GNZ9A49U

1package ch.dola.minecraft.lastlogin;
2
3import java.io.DataInputStream;
4import java.io.FileInputStream;
5import java.io.FileNotFoundException;
6import java.io.IOException;
7import java.io.PrintStream;
8import java.security.InvalidAlgorithmParameterException;
9import java.security.InvalidKeyException;
10import java.security.NoSuchAlgorithmException;
11import java.security.spec.InvalidKeySpecException;
12import java.util.Random;
13
14import javax.crypto.Cipher;
15import javax.crypto.CipherInputStream;
16import javax.crypto.NoSuchPaddingException;
17import javax.crypto.SecretKey;
18import javax.crypto.SecretKeyFactory;
19import javax.crypto.spec.PBEKeySpec;
20import javax.crypto.spec.PBEParameterSpec;
21
22public class Main {
23
24	/**
25	 * Decrypts the username and password from the minecraft lastlogin file, which contains the last saved login informations.
26	 * 
27	 * @param args[0] The path to the lastlogin file in the minecraft directory
28	 */
29	public static void main(String[] args) {
30		
31		PrintStream out = System.out;
32		PrintStream error = System.err;
33		
34		out.println("Starting Minecraft lastlogin decryptor");
35		out.println("--------------------------------------");
36		out.println();
37		if(args.length >= 1){
38			out.println("Inspecting file at " + args[0]);
39			LastLoginDecryptor lld;
40			try {
41				lld = new LastLoginDecryptor(args[0]);
42				out.println("Trying to decrypt data...");
43				out.println();
44				out.println("Username extraced: " + lld.getUsername());
45				out.println("Password extraced: " + lld.getPassword());
46			} catch (FileNotFoundException e) {
47				error.println("Error: Specified File was not found.");
48			} catch (IOException e) {
49				error.println("Error: Could not read from specified file. Maybe permission is missing.");
50			} catch (Exception e) {
51				error.println("Error: An unknown error occured: ");
52				e.printStackTrace();
53			}
54			
55		} else{
56			out.println("Usage:");
57			out.println("java -jar lastlogindecryptor.jar FILENAME");
58			out.println("or make your own executable .sh file including the following line:");
59			out.println("java -jar lastlogindecryptor.jar $1");
60		}
61	}
62	
63	static class LastLoginDecryptor {
64		
65		String password = null;
66		String username = null;
67		
68		boolean decrypted = false;
69		
70		DataInputStream in;
71		
72		public LastLoginDecryptor(String filePath) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeySpecException, InvalidKeyException, InvalidAlgorithmParameterException, FileNotFoundException{
73			Random random = new Random(43287234L);
74			byte[] salt = new byte[8];
75			random.nextBytes(salt);
76			PBEParameterSpec pbeParamSpec = new PBEParameterSpec(salt, 5);
77			SecretKey pbeKey = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(new PBEKeySpec("passwordfile".toCharArray()));
78			Cipher cipher = Cipher.getInstance("PBEWithMD5AndDES");
79			cipher.init(2, pbeKey, pbeParamSpec);
80			
81			in = new DataInputStream(new CipherInputStream(new FileInputStream(filePath), cipher));
82		}
83		
84		private void decrypt() throws IOException{
85			username = in.readUTF();
86			password = in.readUTF();
87			in.close();
88			
89			decrypted = true;
90		}
91		
92		public String getPassword() throws IOException{
93			if (!decrypted){
94				decrypt();
95			}
96			return password;
97		}
98		
99		public String getUsername() throws IOException{
100			if (!decrypted){
101				decrypt();
102			}
103			return username;
104		}
105	}
106}