FmSiLgy7

1func decrypt(encryptedText: String, keys :String)  -> String{
2    let encryptedData = encryptedText.data(using: .utf16LittleEndian)
3    let derivedKey = generateDerivedKey(keyString: keys)
4    let key = Array(derivedKey[0..<32])
5    let iv = Array(derivedKey[32..<48])   
6    let keyData = Data(bytes: key, count: key.count)
7    let ivData = Data(bytes: iv, count: iv.count)        
8    let decryptedData = testDeCrypt(data: encryptedData!, keyData: keyData, ivData: ivData, operation: kCCDecrypt)      
9
10    return String(bytes: decryptedData, encoding: .unicode)!
11}
12
13func generateDerivedKey(keyString :String) -> [Int8] {
14    let salt: [UInt8] = [0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76]
15    var key = [UInt8](repeating: 0, count: 48)
16    CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2), keyString, keyString.utf8.count, salt, salt.count, CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA1), 1000, &key, 48)
17    let derivedKey : [Int8] = key.map {Int8(bitPattern: $0)}
18
19    return derivedKey
20}
21
22func testDeCrypt(data: Data, keyData: Data, ivData: Data, operation: Int) -> Data {
23    assert(keyData.count == Int(kCCKeySizeAES128) || keyData.count == Int(kCCKeySizeAES192) || keyData.count == Int(kCCKeySizeAES256))
24    var decryptedData = Data(count: data.count)
25    var num_bytes_decrypted: size_t = 0
26    let operation = CCOperation(operation)
27    let algoritm = CCAlgorithm(kCCAlgorithmAES)
28    let options = CCOptions(kCCOptionPKCS7Padding)  
29    let cryptoStatus = keyData.withUnsafeBytes {keyDataBytes in
30        ivData.withUnsafeBytes {ivDataBytes in
31            data.withUnsafeBytes {dataBytes in
32                decryptedData.withUnsafeMutableBytes {decryptedDataBytes in
33                    CCCrypt(operation, algoritm, options, keyDataBytes, keyData.count, ivDataBytes, dataBytes, data.count, decryptedDataBytes, decryptedData.count, &num_bytes_decrypted)
34                }
35            }
36        }
37    }      
38    if cryptoStatus == CCCryptorStatus(kCCSuccess) {
39        decryptedData.count = num_bytes_decrypted
40        return decryptedData
41    } else {
42        return Data()
43    }
44}
45	
46public static String aesDecrypt(String text, String key) {
47    byte[] decValue = null;
48    try {
49        byte[] salt = new byte[] { 0x49, 0x76, 0x61, 0x6E, 0x20, 0x4D,
50                0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 };
51        SecretKeyFactory factory = SecretKeyFactory
52                .getInstance("PBKDF2WithHmacSHA1");
53        PBEKeySpec pbeKeySpec = new PBEKeySpec(key.toCharArray(), salt,
54                1000, 384);
55
56        Key secretKey = factory.generateSecret(pbeKeySpec);
57        byte[] keys = new byte[32];
58        byte[] iv = new byte[16];
59        System.arraycopy(secretKey.getEncoded(), 0, key, 0, 32);
60        System.arraycopy(secretKey.getEncoded(), 32, iv, 0, 16);
61
62        SecretKeySpec secretSpec = new SecretKeySpec(keys, "AES");
63
64        AlgorithmParameterSpec ivSpec = new IvParameterSpec(iv);
65        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
66
67        try {
68            cipher.init(Cipher.DECRYPT_MODE, secretSpec, ivSpec);
69        } catch (InvalidKeyException e) {
70
71        } catch (InvalidAlgorithmParameterException e) {
72        }
73
74        org.apache.commons.codec.binary.Base64 decoder = new org.apache.commons.codec.binary.Base64();
75        byte[] decodedValue = decoder.decode(text.getBytes());
76
77        decValue = cipher.doFinal(decodedValue);
78
79    } catch (Exception e) {
80    }
81
82    if (decValue != null) {
83        return new String(decValue, Charset.forName("UTF_16LE"));
84    } else {
85        return null;
86    }
87}