md5変換

    Public Function get_md5string(ByVal base)
        Dim str As Byte() = System.Text.Encoding.ASCII.GetBytes(base)
        Dim md5 As New System.Security.Cryptography.MD5CryptoServiceProvider()
        Dim hash As Byte() = md5.ComputeHash(str)

        'hexa変換
        Dim res As String = BitConverter.ToString(hash).ToLower.Replace("-", "")

        Return res
    End Function