Imports System.Security.Cryptography
Imports System.Text

Public Class Decryption

    Private Shared key As String = "$xzBvyPETUS&amm8)D8x#)f;4%;?[BPd" ' Passwort-Schlüssel (16, 24, or 32 bytes)
    Private Shared iv As String = "1wN&e[zrQ6_B7X/0" ' Initialisierungsvektor (16 bytes)


    ' Entschlüsselungsfunktion
    Public Shared Function Decrypt(cipherText As String) As String
        Dim aesAlg As Aes = Aes.Create()
        aesAlg.Key = Encoding.UTF8.GetBytes(key)
        aesAlg.IV = Encoding.UTF8.GetBytes(iv)
        Dim decryptor As ICryptoTransform = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV)
        Dim cipherBytes As Byte() = Convert.FromBase64String(cipherText)
        Dim msDecrypt As New IO.MemoryStream(cipherBytes)
        Using csDecrypt As New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)
            Using srDecrypt As New IO.StreamReader(csDecrypt)
                Return srDecrypt.ReadToEnd()
            End Using
        End Using
    End Function
End Class