Encrypt and Decrypt a String in ASP.NET C#

I wrote a class to access the Encrypt and Decrypt Method. because I wanted to use this method at many places. And this made my programming simple.

Encrypt and Decrypt Using Class

1. public string DecryptString(string encrString)  
2. {  
3.     byte[] b;  
4.     string decrypted;  
5.     try  
6.     {  
7.         b = Convert.FromBase64String(encrString);  
8.         decrypted = System.Text.ASCIIEncoding.ASCII.GetString(b);  
9.     }  
10.     catch (FormatException fe)   
11.     {  
12.         decrypted = "";  
13.     }  
14.     return decrypted;  
15. }  
16.   
17. public string EnryptString(string strEncrypted)   
18. {  
19.     byte[] b = System.Text.ASCIIEncoding.ASCII.GetBytes(strEncrypted);  
20.     string encrypted = Convert.ToBase64String(b);  
21.     return encrypted;  
22. }  

 Still The above code is not enough for me because I want to do something with my choice. Then I had implemented the code with specify charter to use in Encrypt method. I have created two method class.

 

Encrypt and Decrypt with Character Choice

1. public string encrypt(string encryptString)   
2. {  
3.     string EncryptionKey = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";  
4.     byte[] clearBytes = Encoding.Unicode.GetBytes(encryptString);  
5.     using(Aes encryptor = Aes.Create())   
6.     {  
7.         Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] {  
8.             0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76  
9.         });  
10.         encryptor.Key = pdb.GetBytes(32);  
11.         encryptor.IV = pdb.GetBytes(16);  
12.         using(MemoryStream ms = new MemoryStream())  
13.         {  
14.             using(CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write)) {  
15.                 cs.Write(clearBytes, 0, clearBytes.Length);  
16.                 cs.Close();  
17.             }  
18.             encryptString = Convert.ToBase64String(ms.ToArray());  
19.         }  
20.     }  
21.     return encryptString;  
22. }  
23.   
24. public string Decrypt(string cipherText)   
25. {  
26.     string EncryptionKey = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";  
27.     cipherText = cipherText.Replace(" ", "+");  
28.     byte[] cipherBytes = Convert.FromBase64String(cipherText);  
29.     using(Aes encryptor = Aes.Create())   
30.     {  
31.         Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] {  
32.             0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76  
33.         });  
34.         encryptor.Key = pdb.GetBytes(32);  
35.         encryptor.IV = pdb.GetBytes(16);  
36.         using(MemoryStream ms = new MemoryStream())   
37.         {  
38.             using(CryptoStream cs = new CryptoStream(ms, encryptor.CreateDecryptor(), CryptoStreamMode.Write)) {  
39.                 cs.Write(cipherBytes, 0, cipherBytes.Length);  
40.                 cs.Close();  
41.             }  
42.             cipherText = Encoding.Unicode.GetString(ms.ToArray());  
43.         }  
44.     }  
45.     return cipherText;  
46. }  

At last the above code is totally perfect to make such a good application and now I'm filling good because I did what I want.