(PowerShell) AES Encryption ECB Mode with PKCS7 Padding

Duplicates the following C# code:

public static byte[] DecryptBySymmetricKey(string encryptedText, byte[] key)
  {
     string keyAsBase64 = Convert.ToBase64String(key);

     byte[] dataToDecrypt = Convert.FromBase64String(encryptedText);
     var keyBytes = key;
     AesManaged tdes = new AesManaged();
     tdes.KeySize = 256;
     tdes.BlockSize = 128;
     tdes.Key = keyBytes;
     tdes.Mode = CipherMode.ECB;
     tdes.Padding = PaddingMode.PKCS7;
     ICryptoTransform decrypt__1 = tdes.CreateDecryptor();
     byte[] deCipher = decrypt__1.TransformFinalBlock(dataToDecrypt, 0, dataToDecrypt.Length);
     tdes.Clear();
     string EK_result = Convert.ToBase64String(deCipher);
     return EK_result;
}

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$crypt = New-Object Chilkat.Crypt2

# In the C# code above that is to be duplicated here, use the base64 encoded key.
$keyAsBase64 = "..."
$encryptedBytesAsBase64 = "...."

$crypt.KeyLength = 256
$crypt.CryptAlgorithm = "AES"
$crypt.CipherMode = "ecb"
$crypt.PaddingScheme = 0
$crypt.SetEncodedKey($keyAsBase64,"base64")

$crypt.EncodingMode = "base64"

# Pass the base64 representation of the encrypted data.
# (The EncodingMode indicates you are passing base64.)
$EK_result = $crypt.DecryptStringENC($encryptedBytesAsBase64)

$($EK_result)