Decodes the password. - CSharp Security

CSharp examples for Security:Password

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Description

Decodes the password.

Demo Code


using System.Threading.Tasks;
using System.Text;
using System.Security.Cryptography;
using System.Linq;
using System.Collections.Generic;
using System;//from w ww  . j  av  a2  s.  c  om

public class Main{
        /// <summary>
        /// Decodes the password.
        /// </summary>
        /// <param name="Message">The message.</param>
        /// <returns></returns>
        public static string DecodePassword(string Message)
        {
            byte[] Results;
            string Passphrase = "secret";
            System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();

            // Step 1. We hash the passphrase using MD5
            // We use the MD5 hash generator as the result is a 128 bit byte array
            // which is a valid length for the TripleDES encoder we use below

            MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider();
            byte[] TDESKey = HashProvider.ComputeHash(UTF8.GetBytes(Passphrase));

            // Step 2. Create a new TripleDESCryptoServiceProvider object
            TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider();

            // Step 3. Setup the decoder
            TDESAlgorithm.Key = TDESKey;
            TDESAlgorithm.Mode = CipherMode.ECB;
            TDESAlgorithm.Padding = PaddingMode.PKCS7;

            // Step 4. Convert the input string to a byte[]
            byte[] DataToDecrypt = Convert.FromBase64String(Message);

            // Step 5. Attempt to decrypt the string
            try
            {
                ICryptoTransform Decryptor = TDESAlgorithm.CreateDecryptor();
                Results = Decryptor.TransformFinalBlock(DataToDecrypt, 0, DataToDecrypt.Length);
            }
            finally
            {
                // Clear the TripleDes and Hashprovider services of any sensitive information
                TDESAlgorithm.Clear();
                HashProvider.Clear();
            }

            // Step 6. Return the decrypted string in UTF8 format
            return UTF8.GetString(Results);
        }
}

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