Encoding and Decoding Password in login Form from Database

Question

I am making a Registration and a login Form with encoded password saved to database, I can encode the password using encodin.utf8.

 

Problem is I register with some username and password and the data get saved to database with encoded password, but when I login with the same data it shows me this below error. 

Invalid length for a Base-64 char array or string.

 

Can anyone give me the described solution for this.  Below I am attaching my encoded and decoded methods :

 

 

Encoded :

 

 

private string encryption(string clearText)
   {

       string encryptkey = "123";
       byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
       using (Aes encrypt = Aes.Create())
       {


           Rfc2898DeriveBytes rdb = new Rfc2898DeriveBytes(encryptkey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
           encrypt.Key = rdb.GetBytes(32);
           encrypt.IV = rdb.GetBytes(16);

           using (MemoryStream ms = new MemoryStream())
           {

               using (CryptoStream cst = new CryptoStream(ms, encrypt.CreateEncryptor(), CryptoStreamMode.Write))
               {
                   cst.Write(clearBytes, 0, clearBytes.Length);
                   cst.Close();
               }

               clearText = Convert.ToBase64String(ms.ToArray());

           }

       }


       return clearText;

 

 

 

Decoded :

 

 

 

private string decryp(string cipherText)
{

cipherText = cipherText.Replace(" ", "+");
string decryptkey = "123";
byte[] cipherBytes = Convert.FromBase64String(cipherText.Replace(" ", "+"));
using (Aes encrypt = Aes.Create())
{

Rfc2898DeriveBytes rdb = new Rfc2898DeriveBytes(decryptkey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encrypt.Key = rdb.GetBytes(32);
encrypt.IV = rdb.GetBytes(16);


using (MemoryStream ms = new MemoryStream())
{

using (CryptoStream cst = new CryptoStream(ms, encrypt.CreateDecryptor(), CryptoStreamMode.Write))
{

cst.Write(cipherBytes, 0, cipherBytes.Length);
cst.Close();

}

cipherText = Encoding.Unicode.GetString(ms.ToArray());

}

}

return cipherText;