vPUiymeZ

1import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
2
3import javax.crypto.Cipher;
4import javax.crypto.spec.IvParameterSpec;
5import javax.crypto.spec.SecretKeySpec;
6
7public class AesCipher {
8
9    private static String CIPHER_NAME = "AES/CBC/PKCS5PADDING";
10
11    private static int CIPHER_KEY_LEN = 16; //128 bits
12
13    public static String urlSafeBase64Encode(byte[] data) {
14        String encodeBase64 = Base64.encode(data);
15        String safeBase64Str = encodeBase64.replace('+', '-');
16        safeBase64Str = safeBase64Str.replace('/', '_');
17        safeBase64Str = safeBase64Str.replaceAll("=", "");
18        return safeBase64Str;
19    }
20
21    public static byte[] urlSafeBase64Decode(final String safeBase64Str) {
22        String base64Str = safeBase64Str.replace('-', '+');
23        base64Str = base64Str.replace('_', '/');
24        int mod4 = base64Str.length() % 4;
25        if (mod4 > 0) {
26            base64Str = base64Str + "====".substring(mod4);
27        }
28        return Base64.decode(base64Str);
29    }
30
31    /**
32     * AES-128-CBC加密
33     *
34     * @param key
35     * @param iv
36     * @param data
37     * @return
38     */
39    public static String encrypt(String key, String iv, String data) {
40
41        try {
42            IvParameterSpec ivSpec = new IvParameterSpec(iv.getBytes("UTF-8"));
43            SecretKeySpec secretKey = new SecretKeySpec(fixKey(key).getBytes("UTF-8"), "AES");
44
45            Cipher cipher = Cipher.getInstance(AesCipher.CIPHER_NAME);
46            cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivSpec);
47
48            byte[] encryptedData = cipher.doFinal((data.getBytes()));
49
50            String encryptedDataInBase64 = urlSafeBase64Encode(encryptedData);
51            String ivInBase64 = urlSafeBase64Encode(iv.getBytes("UTF-8"));
52
53            return encryptedDataInBase64 + ":" + ivInBase64;
54
55        } catch (Exception ex) {
56            throw new RuntimeException(ex);
57        }
58    }
59
60    private static String fixKey(String key) {
61
62        if (key.length() < AesCipher.CIPHER_KEY_LEN) {
63            int numPad = AesCipher.CIPHER_KEY_LEN - key.length();
64
65            for (int i = 0; i < numPad; i++) {
66                key += "0"; //0 pad to len 16 bytes
67            }
68
69            return key;
70
71        }
72
73        if (key.length() > AesCipher.CIPHER_KEY_LEN) {
74            return key.substring(0, CIPHER_KEY_LEN); //truncate to 16 bytes
75        }
76
77        return key;
78    }
79
80    /**
81     * AES-128-CBC解密
82     *
83     * @param key
84     * @param data
85     * @return
86     */
87
88    public static String decrypt(String key, String data) {
89
90        try {
91            String[] parts = data.split(":");
92
93            IvParameterSpec iv = new IvParameterSpec(urlSafeBase64Decode(parts[1]));
94            SecretKeySpec secretKey = new SecretKeySpec(fixKey(key).getBytes(), "AES");
95
96            Cipher cipher = Cipher.getInstance(AesCipher.CIPHER_NAME);
97            cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
98
99            byte[] decodedEncryptedData = urlSafeBase64Decode(parts[0]);
100
101            byte[] original = cipher.doFinal(decodedEncryptedData);
102
103            return new String(original);
104        } catch (Exception ex) {
105            throw new RuntimeException(ex);
106        }
107    }
108
109    public static void main(String[] args) {
110
111        String key = "9da76eb9f16e6ddf2de8eaf927d81c52"; // 128 bit key
112        String initVector = key.substring(0, 16); // 16 bytes IV, it is recommended to use a different random IV for every message!
113
114        String plain_text = "mima";
115        String encrypted = encrypt(key, initVector, plain_text);
116        System.out.println(encrypted);
117
118        String decrypt = decrypt(key, encrypted);
119        System.out.println(decrypt);
120    }
121}