三重DES解密问题

我已经使用 Visual Basic 中的以下函数使用 3des 解码了字符串 "Test"：

Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Friend Class cTripleDES
    ' define the triple des provider
    Private m_des As New TripleDESCryptoServiceProvider
    ' define the string handler
    Private m_utf8 As New ASCIIEncoding
    ' define the local property arrays
    Private m_key() As Byte
    Private m_iv() As Byte
    Public Sub New(ByVal key() As Byte, ByVal iv() As Byte)
        Me.m_key = key
        Me.m_iv = iv
    End Sub
    Public Function Encrypt(ByVal input() As Byte) As Byte()
        Return Transform(input, m_des.CreateEncryptor(m_key, m_iv))
    End Function
    Public Function Decrypt(ByVal input() As Byte) As Byte()
        Return Transform(input, m_des.CreateDecryptor(m_key, m_iv))
    End Function
    Public Function Encrypt(ByVal text As String) As String
        Dim input() As Byte = m_utf8.GetBytes(text)
        Dim output() As Byte = Transform(input, _
                        m_des.CreateEncryptor(m_key, m_iv))
        Return Convert.ToBase64String(output)
    End Function
    Public Function Decrypt(ByVal text As String) As String
        Dim input() As Byte = Convert.FromBase64String(text)
        Dim output() As Byte = Transform(input, _
                         m_des.CreateDecryptor(m_key, m_iv))
        Return m_utf8.GetString(output)
    End Function
    Private Function Transform(ByVal input() As Byte, _
        ByVal CryptoTransform As ICryptoTransform) As Byte()
        ' create the necessary streams
        Dim memStream As MemoryStream = New MemoryStream
        Dim cryptStream As CryptoStream = New  _
            CryptoStream(memStream, CryptoTransform, _
            CryptoStreamMode.Write)
        ' transform the bytes as requested
        cryptStream.Write(input, 0, input.Length)
        cryptStream.FlushFinalBlock()
        ' Read the memory stream and convert it back into byte array
        memStream.Position = 0
        Dim result(CType(memStream.Length - 1, System.Int32)) As Byte
        memStream.Read(result, 0, CType(result.Length, System.Int32))
        ' close and release the streams
        memStream.Close()
        cryptStream.Close()
        ' hand back the encrypted buffer
        Return result
    End Function

我用这个函数调用了它

Imports System.Security.Cryptography
Imports System.IO
Imports System.Text
Module tripledes
    Function Encrypt(ByVal text As String) As String
        ' define the local key and vector byte arrays
        Dim key() As Byte = Encoding.ASCII.GetBytes("MyKeygoeshere12345678901")
        Dim iv() As Byte = Encoding.ASCII.GetBytes("Heretheiv")
        ' instantiate the class with the arrays
        Dim des As New cTripleDES(key, iv)
        ' the value of decryptedData should be "test",
        ' but for our example purposes, let's re-encrypt it
        Return des.Encrypt(text)
    End Function
    Function Decrypt(ByVal text As String) As String
        ' define the local key and vector byte arrays
        Dim key() As Byte = Encoding.ASCII.GetBytes("MyKeygoeshere12345678901")
        Dim iv() As Byte = Encoding.ASCII.GetBytes("Heretheiv")
        ' instantiate the class with the arrays
        Dim des As New cTripleDES(key, iv)
        ' the value of decryptedData should be "test",
        ' but for our example purposes, let's re-encrypt it
        Return des.Decrypt(text)
    End Function
End Module

但是，如果我尝试使用以下 PHP 函数解密它，则输出是 agkk 而不是 Test 作为我的输入和我例外。

function decrypt($content){
$key = "MyKeygoeshere12345678901";
$iv = "Heretheiv";
return  mcrypt_cbc(MCRYPT_3DES, $key,  base64_decode($content), MCRYPT_DECRYPT, $iv);
}

有人可以告诉我我做错了什么吗？