1 public static string Decrypt(string combinedString, string keyString)
2 {
3 string plainText;
4 byte[] combinedData = Convert.FromBase64String(combinedString);
5 Aes aes = Aes.Create();
6 aes.Key = Encoding.UTF8.GetBytes(keyString);
7 byte[] iv = new byte[aes.BlockSize / 8];
8 byte[] cipherText = new byte[combinedData.Length - iv.Length];
9 Array.Copy(combinedData, iv, iv.Length);
10 Array.Copy(combinedData, iv.Length, cipherText, 0, cipherText.Length);
11 aes.IV = iv;
12 aes.Mode = CipherMode.CBC;
13 ICryptoTransform decipher = aes.CreateDecryptor(aes.Key, aes.IV);
14
15 using (MemoryStream ms = new MemoryStream(cipherText))
16 {
17 using (CryptoStream cs = new CryptoStream(ms, decipher, CryptoStreamMode.Read))
18 {
19 using (StreamReader sr = new StreamReader(cs))
20 {
21 plainText = sr.ReadToEnd();
22 }
23 }
24
25 return plainText;
26 }
27 }
28
29 public static string Encrypt(string plainText, string keyString)
30 {
31 byte[] cipherData;
32 Aes aes = Aes.Create();
33 aes.Key = Encoding.UTF8.GetBytes(keyString);
34 aes.GenerateIV();
35 aes.Mode = CipherMode.CBC;
36 ICryptoTransform cipher = aes.CreateEncryptor(aes.Key, aes.IV);
37
38 using (MemoryStream ms = new MemoryStream())
39 {
40 using (CryptoStream cs = new CryptoStream(ms, cipher, CryptoStreamMode.Write))
41 {
42 using (StreamWriter sw = new StreamWriter(cs))
43 {
44 sw.Write(plainText);
45 }
46 }
47
48 cipherData = ms.ToArray();
49 }
50
51 byte[] combinedData = new byte[aes.IV.Length + cipherData.Length];
52 Array.Copy(aes.IV, 0, combinedData, 0, aes.IV.Length);
53 Array.Copy(cipherData, 0, combinedData, aes.IV.Length, cipherData.Length);
54 return Convert.ToBase64String(combinedData);
55 }
