geGSYXmR

1package com.itc.classmate.utils;
2
3import android.util.Base64;
4
5import com.itc.classmate.application.MyApplication;
6
7import java.io.UnsupportedEncodingException;
8import java.security.InvalidAlgorithmParameterException;
9import java.security.InvalidKeyException;
10import java.security.KeyPair;
11import java.security.KeyPairGenerator;
12import java.security.NoSuchAlgorithmException;
13import java.security.PrivateKey;
14import java.security.PublicKey;
15import java.security.SecureRandom;
16import java.security.spec.InvalidKeySpecException;
17import java.security.spec.KeySpec;
18
19import javax.crypto.BadPaddingException;
20import javax.crypto.Cipher;
21import javax.crypto.IllegalBlockSizeException;
22import javax.crypto.KeyGenerator;
23import javax.crypto.NoSuchPaddingException;
24import javax.crypto.SecretKey;
25import javax.crypto.SecretKeyFactory;
26import javax.crypto.spec.IvParameterSpec;
27import javax.crypto.spec.PBEKeySpec;
28import javax.crypto.spec.SecretKeySpec;
29
30/**
31 * Created by 23508 on 3/27/2018.
32 */
33
34public enum EncryptMoreThn256Byte {
35    INSTANCE;
36    private SecretKey secKey;
37   // private String ACCESS_TOKEN = "bearer nG25Uokr3eF0WAisEcoS4hb1isLwR2qbOGu3UnwARGfeBNlP7RToSf3DCmowl99-TX0nrwL1qElIRZALFNbBXQPL6weVhJk9LRjJAoD9oBlTPtfDNMAZXlLqBqWnYZoxNyfQoPUE_Y0iMBcj_j6RqOfJc4Npid7Wo1AoipXOPYt1JLMfdHN9TZvtn6SxNP9UFipDANkcnHsurDwjPV_X0PdzyqsgXuoIjfAQLd7IonVYGZYmB_SYO68q5CorhH7hA01iIm7TDeUrOAM1p2C9W84rV6nMzMZS-7LPoweMWPxaLHcj15ex3TR16PGNGwbfiRPMLxNjmpqQEi3Mfqax2mk9qHL6LNb-OQK_5y9Zo9w1nC55iQhM-PbF96kgYa5zM2o94yI1IhcWAs-fJEe5tPsT3Dj_QfLWeNVblzDysfNwNajCGnauuPLzG-5qrGgNRtw0Dou8eNhk1lplDXxqu-G9kRyK1KKnPtuyCawzEJ_-4aEHdeA3-QSEqWCphu6w";
38  //  private String initialText = "this is working";
39
40    private EncryptMoreThn256Byte() {
41        AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "called constructor of EncryptMoreThn256Byte");
42        KeyGenerator generator = null;
43        try {
44            generator = KeyGenerator.getInstance("AES");
45            generator.init(128); // The AES key size in number of bits
46            secKey = generator.generateKey();
47            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "EncryptMoreThn256Byte: secKey+++ " + secKey.getEncoded());
48
49//            SecureRandom random = new SecureRandom();
50//            byte[] salt = new byte[(256/8)];
51//            random.nextBytes(salt);
52//            KeySpec keySpec = new PBEKeySpec(initialText.toCharArray(), salt, 1000, 256);
53//            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
54//            byte[] decrptedSecrateKey = keyFactory.generateSecret(keySpec).getEncoded();
55//           // secKey = new SecretKeySpec(decrptedSecrateKey, "AES");
56//            secKey = new SecretKeySpec(decrptedSecrateKey, 0, decrptedSecrateKey.length, "AES");
57        } catch (Exception e) {
58            AppLog.errLog(EncryptMoreThn256Byte.class.getSimpleName(), e.getMessage());
59        }
60    }
61
62
63    public String encryptAccessTokenUsingAES(String plainText) {
64        AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptAccessTokenUsingAES: plainText " + plainText);
65
66        if (plainText != null || !plainText.isEmpty()) {
67            String encrytedSecretKey = SharedPreferences.getInstance(MyApplication.getInstance().getApplicationContext()).getEncrytedSecretKey();
68            if (encrytedSecretKey != null) {
69                AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptAccessTokenUsingAES: encrytedSecretKey >+++ " + encrytedSecretKey);
70                byte[] decrptedSecrateKey = decryptSecretKeyUsingRSA(encrytedSecretKey);
71                if (decrptedSecrateKey != null) {
72                    secKey = new SecretKeySpec(decrptedSecrateKey, 0, decrptedSecrateKey.length, "AES");
73                }
74            } else {
75                encryptSecretKeyUsingRSA(secKey);
76            }
77
78            String str = new String(encryptText(secKey, plainText));
79            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "final encryptAccessTokenUsingAES is: " + str);
80            return str;
81        }
82
83        AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptAccessTokenUsingAES: value " + null);
84        return null;
85    }
86
87
88    public String decryptAccessTokenUsingAES(String encrptedAssessToken) {
89        String encrpted_secretkey = SharedPreferences.getInstance(MyApplication.getInstance().getApplicationContext()).getEncrytedSecretKey();
90        AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "decryptAccessTokenUsingAES encrpted_secretkey:: " + encrpted_secretkey);
91        AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "decryptAccessTokenUsingAES accesstoken:: " + encrptedAssessToken);
92        if (encrpted_secretkey != null) {
93            byte[] decrptedSecrateKey = decryptSecretKeyUsingRSA(encrpted_secretkey);
94            if (decrptedSecrateKey != null) {
95                SecretKey secKey = new SecretKeySpec(decrptedSecrateKey, 0, decrptedSecrateKey.length, "AES");
96                AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "decryptAccessTokenUsingAES secKey.getEncoded():: " + secKey.getEncoded());
97                String str = decryptText(secKey, encrptedAssessToken);
98                AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "final decryptAccessTokenUsingAES is: " + str);
99                return str;
100            }
101        }
102        return null;
103    }
104
105    private byte[] encryptSecretKeyUsingRSA(SecretKey secKey) {
106        AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptSecretKeyUsingRSA SecretKey:: " + secKey);
107        KeyPairGenerator kpg = null;
108        byte[] encryptedSecrteKey = null;
109        try {
110            kpg = KeyPairGenerator.getInstance("RSA");
111            kpg.initialize(2048);
112            KeyPair keyPair = kpg.generateKeyPair();
113            PublicKey puKey = keyPair.getPublic();
114            Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
115            cipher.init(Cipher.PUBLIC_KEY, puKey);
116            //AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptSecretKeyUsingRSA secKey.getEncoded():: " + secKey.getEncoded());
117            //AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptSecretKeyUsingRSA secKey.getEncoded().length:: " + secKey.getEncoded().length);
118            //byte[] encryptedSecrteKey = cipher.doFinal(secKey.getEncoded());
119            //byte[] encryptedSecrteKey=cipher.doFinal(initialText.getBytes("UTF-8"));
120            encryptedSecrteKey = cipher.doFinal(secKey.getEncoded());
121            // String str =  Base64.encodeToString(encryptedSecrteKey, Base64.DEFAULT);
122            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptSecretKeyUsingRSA encryptedSecrteKey[]:: " + encryptedSecrteKey.length);
123            //AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptSecretKeyUsingRSA encrytionSecretKey:: " + str);
124            //AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptSecretKeyUsingRSA encrytionSecretKey length:: " + str.length());
125            SharedPreferences.getInstance(MyApplication.getInstance().getApplicationContext()).setEncrytedSecretKey(encryptedSecrteKey.toString());
126        } catch (Exception e) {
127            AppLog.errLog(EncryptMoreThn256Byte.class.getSimpleName(), "encryptSecretKeyUsingRSA::+" + e.getMessage());
128        } finally {
129            return encryptedSecrteKey;
130        }
131    }
132
133
134    private byte[] decryptSecretKeyUsingRSA(String encryptSecretKey) {
135        KeyPairGenerator kpg = null;
136        byte[] bytes = null;
137        try {
138            kpg = KeyPairGenerator.getInstance("RSA");
139            kpg.initialize(2048);
140            KeyPair keyPair = kpg.generateKeyPair();
141            PrivateKey prKey = keyPair.getPrivate();
142            Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
143            cipher.init(Cipher.PRIVATE_KEY, prKey);
144            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "decryptSecretKeyUsingRSA encryptSecretKey.getBytes():: " + encryptSecretKey.getBytes());
145            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "decryptSecretKeyUsingRSA encryptSecretKey.getBytes().length:: " + encryptSecretKey.getBytes().length);
146           // bytes = cipher.doFinal(Base64.decode(encryptSecretKey, Base64.DEFAULT));
147            bytes = cipher.doFinal(encryptSecretKey.getBytes());
148            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "decryptSecretKeyUsingRSA cipher.doFinal(encryptSecretKey.getBytes():: " + bytes.toString());
149        } catch (Exception e) {
150            AppLog.errLog(EncryptMoreThn256Byte.class.getSimpleName(), "decryptSecretKeyUsingRSA++++ " + e.getMessage());
151        }
152        return bytes;
153    }
154
155
156    private byte[] encryptText(SecretKey pSecKey, String plainText) {
157        byte[] encryptAccessToken = null;
158        try {
159            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptText::secKey: " + pSecKey.getEncoded());
160            Cipher aesCipher = Cipher.getInstance("AES");
161            aesCipher.init(Cipher.ENCRYPT_MODE, pSecKey);
162            encryptAccessToken = aesCipher.doFinal(plainText.getBytes());
163            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptText:::: " + encryptAccessToken.toString());
164        } catch (Exception e) {
165            AppLog.errLog(EncryptMoreThn256Byte.class.getSimpleName(), "encryptTextUsingAES " + e.getMessage());
166        }
167        return encryptAccessToken;
168    }
169
170    /**
171     * Convert bytes to AES SecertKey so we can decrypt access token
172     *
173     * @return
174     */
175    private String decryptText(SecretKey originalKey, String decryptedAccessToken) {
176        byte[] bytePlainText = null;
177        try {
178            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "encryptText::originalKey: " + originalKey.getEncoded());
179            //SecretKey originalKey = new SecretKeySpec(decryptedKey, 0, decryptedKey.length, "AES");
180            Cipher aesCipher = null;
181            aesCipher = Cipher.getInstance("AES");
182            aesCipher.init(Cipher.DECRYPT_MODE, originalKey);
183            bytePlainText = aesCipher.doFinal(decryptedAccessToken.getBytes());
184            AppLog.log(EncryptMoreThn256Byte.class.getSimpleName(), "decryptText bytePlainText:: " + bytePlainText.toString());
185        } catch (Exception e) {
186            AppLog.errLog(EncryptMoreThn256Byte.class.getSimpleName(), "encryptTextUsingAES " + e.getMessage());
187        }
188        return new String(bytePlainText);
189    }
190
191
192    private byte[] encrytAT(String plaintext, String password) throws InvalidAlgorithmParameterException, InvalidKeyException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, UnsupportedEncodingException, BadPaddingException, IllegalBlockSizeException {
193        SecureRandom random = new SecureRandom();
194        byte[] salt = new byte[(256 / 8)];
195        random.nextBytes(salt);
196        KeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt, 1000, 256);
197        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
198        byte[] keyBytes = keyFactory.generateSecret(keySpec).getEncoded();
199        SecretKey key = new SecretKeySpec(keyBytes, "AES");
200        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
201        byte[] iv = new byte[cipher.getBlockSize()];
202        random.nextBytes(iv);
203        IvParameterSpec ivParams = new IvParameterSpec(iv);
204        cipher.init(Cipher.ENCRYPT_MODE, key, ivParams);
205        return cipher.doFinal(plaintext.getBytes("UTF-8"));
206    }
207
208}