Imports System.Text
Imports System.Security.Cryptography

Public Class _3des
    Public Shared Function a(ByVal b As String, ByVal c As String, ByVal d As Boolean) As String
        Dim ReplacedkeyArray As Byte()
        Dim ReplacedtoEncryptArray As Byte() = Convert.FromBase64String(b)

        If d Then
            Dim Replacedhashmd5 = New MD5CryptoServiceProvider()
            ReplacedkeyArray = Replacedhashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(c))
        Else
            ReplacedkeyArray = UTF8Encoding.UTF8.GetBytes(c)
        End If

        Dim Replacedtdes = New TripleDESCryptoServiceProvider()
        Replacedtdes.Key = ReplacedkeyArray
        Replacedtdes.Mode = CipherMode.ECB
        Replacedtdes.Padding = PaddingMode.PKCS7

        Dim ReplacedcTransform As ICryptoTransform = Replacedtdes.CreateDecryptor()
        Dim ReplacedresultArray As Byte() = ReplacedcTransform.TransformFinalBlock(ReplacedtoEncryptArray, 0, ReplacedtoEncryptArray.Length)

        Return UTF8Encoding.UTF8.GetString(ReplacedresultArray)
    End Function
End Class