jJBRHr1K

1import java.security.Key;
2import java.security.KeyFactory;
3import java.security.NoSuchAlgorithmException;
4import java.security.PrivateKey;
5import java.security.spec.InvalidKeySpecException;
6import java.security.spec.PKCS8EncodedKeySpec;
7import java.util.Base64;
8 
9import javax.crypto.Cipher;
10import javax.crypto.KeyGenerator;
11import javax.crypto.SecretKey;
12import javax.crypto.spec.SecretKeySpec;
13 
14 
15import org.json.JSONObject;
16 
17 
18public class ProcessData {
19    
20    private PrivateKey privatekey ;
21    private String aesKey = "";
22    private String resp = "";
23    private String jsonstr = "";
24        
25    public String getSecretAESKeyAsString() throws Exception {
26 
27        KeyGenerator generator = KeyGenerator.getInstance("AES");
28        generator.init(256); // The AES key size in number of bits
29        SecretKey secKey = generator.generateKey();
30        String encodedKey = Base64.getEncoder().encodeToString(secKey.getEncoded());
31        return encodedKey;
32    }
33 
34    // Decrypt text using AES key
35    public String decryptTextUsingAES(String aesKeyString) throws Exception {
36 
37        byte[] decodedKey = Base64.getDecoder().decode(aesKeyString);
38        SecretKey originalKey = new SecretKeySpec(decodedKey, 0, decodedKey.length, "AES");
39 
40        // AES defaults to AES/ECB/PKCS5Padding in Java 7
41        Cipher aesCipher = Cipher.getInstance("AES");
42        aesCipher.init(Cipher.DECRYPT_MODE, originalKey);
43        byte[]data = Base64.getDecoder().decode(this.resp.getBytes());
44 
45        byte[] bytePlainText = aesCipher.doFinal(data);
46        return new String(bytePlainText);
47    }
48 
49 
50    // Decrypt AES Key using RSA public key
51    private String decryptAESKey(byte[] encryptedAESKey, PrivateKey privateKey) throws Exception {
52        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
53        cipher.init(Cipher.DECRYPT_MODE, privateKey);
54        
55        return new String(cipher.doFinal(encryptedAESKey));
56    }
57 
58 
59    public String decryptData() throws Exception {
60            return decryptAESKey(Base64.getDecoder().decode(this.aesKey.getBytes()), this.privatekey);
61    }
62    
63    public Key getPublicKey(String pubkey) {
64        Key test = null;
65        
66        return test;
67        
68    }
69    public PrivateKey getPrivateKey(String b64) {
70        
71        
72        return this.privatekey;
73        
74    }
75    public void setPrivateKey(String skey) {
76 
77        KeyFactory kf = null;
78        try {
79            kf = KeyFactory.getInstance("RSA");
80        } catch (NoSuchAlgorithmException e) {
81            // TODO Auto-generated catch block
82            e.printStackTrace();
83        }
84        PKCS8EncodedKeySpec keySpecPKCS8 = new PKCS8EncodedKeySpec(Base64.getDecoder().decode(skey));
85        PrivateKey privKey = null;
86        try {
87            privKey = kf.generatePrivate(keySpecPKCS8);
88        } catch (InvalidKeySpecException e) {
89            // TODO Auto-generated catch block
90            e.printStackTrace();
91        }
92        this.privatekey = privKey;
93    }
94    public static void main(String[] args) {
95 
96        ProcessData pd = new ProcessData();
97        
98        JSONObject json = new JSONObject(pd.jsonstr);
99        String skey =  (String)json.get("partnerPrivateKey");
100        String decryptAes = null;
101        pd.setPrivateKey(skey);
102        try {
103            decryptAes = pd.decryptData();
104        } catch (Exception e) {
105            // TODO Auto-generated catch block
106            e.printStackTrace();
107        }
108        String message = null;
109        try {
110            message = pd.decryptTextUsingAES(decryptAes);
111        } catch (Exception e) {
112            // TODO Auto-generated catch block
113            e.printStackTrace();
114        }
115        System.out.println(message);
116    }
117    
118}
119