Convert c# funtion to dart function

I need to convert a function writed on c# which is related to encryption, to the Dart function.

Just convert "Decrypt" to the Dart
The c# function is:
```cs
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace ConsoleApplication1
{
internal class Program
{
static System.String password ="VNDz28kCU$svA8kz6qG^";
static System.String saltPassword = "sars-cov-2";


public static void Main(string[] args)
{
Console.WriteLine("TargetVal: "+Decrypt(Uri.UnescapeDataString("c2Fycy1jb3YtMme29InkW0bbclny017AZgc%3D"), password, saltPassword));
// output: "Classic1"
}

public static string Decrypt(string strEncript, string password, string saltpassword)
{
int Iterations = 555;

try
{
byte[] cipherBytes = Convert.FromBase64String(strEncript);

using (var memoryStream = new MemoryStream(cipherBytes))
{
DESCryptoServiceProvider des = new DESCryptoServiceProvider();

byte[] iv = GetIV(saltpassword);
memoryStream.Read(iv, 0, iv.Length);

// use derive bytes to generate key from password and IV
var rfc2898DeriveBytes = new Rfc2898DeriveBytes(password, iv, Iterations);

byte[] key = rfc2898DeriveBytes.GetBytes(8);

using (var cryptoStream = new CryptoStream(memoryStream, des.CreateDecryptor(key, iv), CryptoStreamMode.Read))
using (var streamReader = new StreamReader(cryptoStream))
{
string strPlain = streamReader.ReadToEnd();
return strPlain;
}
}
}
catch (Exception e)
{
return strEncript;
}

}

static byte[] GetIV(System.String strSalt)
{
byte[] IV = Encoding.UTF8.GetBytes(strSalt);
return IV;
}

}
}
```