ใช้ฟังชั่น cUrl Login เข้าเว็บที่เป็น asp.net แล้วมันขึ้น System.FormatException: Invalid character in a Base-64 string.

  Public Sub DecodeWithString()
   Dim inFile As System.IO.StreamReader
   Dim base64String As String

   Try
      Dim base64CharArray() As Char
      inFile = New System.IO.StreamReader(inputFileName, _
                                          System.Text.Encoding.ASCII)
      base64CharArray = New Char(inFile.BaseStream.Length) {}
      inFile.Read(base64CharArray, 0, inFile.BaseStream.Length)
      base64String = New String(base64CharArray, _
                                0, _
                                base64CharArray.Length - 1)
   Catch exp As System.Exception
      ' Error creating stream or reading from it.
      System.Console.WriteLine("{0}", exp.Message)
      Return
   End Try

   ' Convert the Base64 UUEncoded input into binary output.
   Dim binaryData() As Byte
   Try
      binaryData = System.Convert.FromBase64String(base64String)
   Catch exp As System.ArgumentNullException
      System.Console.WriteLine("Base 64 string is null.")
      Return
   Catch exp As System.FormatException
      System.Console.WriteLine("Base 64 length is not 4 or is " + _
                               "not an even multiple of 4.")
      Return
   End Try

   'Write out the decoded data.
   Dim outFile As System.IO.FileStream
   Try
      outFile = New System.IO.FileStream(outputFileName, _
                                         System.IO.FileMode.Create, _
                                         System.IO.FileAccess.Write)
      outFile.Write(binaryData, 0, binaryData.Length - 1)
      outFile.Close()
   Catch exp As System.Exception
      ' Error creating stream or writing to it.
      System.Console.WriteLine("{0}", exp.Message)
   End Try
End Sub

 <?php // สร้าง cookie
$cookie_file_path = "/path/to/cookie.txt";
$LOGINURL = "http://www.example.com/login.aspx";
$agent = "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax)";
 
// ทำการ login 
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$LOGINURL);
curl_setopt($ch, CURLOPT_USERAGENT, $agent);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_COOKIEFILE, $cookie_file_path);
curl_setopt($ch, CURLOPT_COOKIEJAR, $cookie_file_path);
$result = curl_exec ($ch);
curl_close ($ch);
unset($ch); 
 
// ค้นหา view state ปัจจุบัน
preg_match('/<input type="hidden" name="__VIEWSTATE" value="([^";]*?)"; \/>/', $result, $matches);
$viewstate = $matches[1];
$viewstate = urlencode($viewstate);
 
//ทำการเรียกใช้งานฟังก์ชั่นที่ต้องการ
$POSTURL = "http://www.example.com/main.aspx";
$reffer = "http://www.example.com/main.aspx";
$POSTFIELDS = "__EVENTTARGET=&amp;__EVENTARGUMENT=&__VIEWSTATE=$viewstate&txtARG1=$arg1&txtARG2=$arg2";
 
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$POSTURL);
curl_setopt($ch, CURLOPT_USERAGENT, $agent);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS,$POSTFIELDS);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_REFERER, $reffer);
curl_setopt($ch, CURLOPT_COOKIEFILE, $cookie_file_path);
curl_setopt($ch, CURLOPT_COOKIEJAR, $cookie_file_path);
$result = curl_exec ($ch); 
curl_close ($ch);
unset($ch);
echo $result;
 
// ค้นหา view state ปัจจุบัน
preg_match('/<input type="hidden"; name="__VIEWSTATE" value="([^"]*?)"; \/>/', $result, $matches);
$viewstate = $matches[1];
$viewstate = urlencode($viewstate);
//Log out
$LOGOFFURL = "http://www.example.com/logOff.aspx";
$agent = "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax)";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$LOGOFFURL);
curl_setopt($ch, CURLOPT_USERAGENT, $agent);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_COOKIEFILE, $cookie_file_path);
curl_setopt($ch, CURLOPT_COOKIEJAR, $cookie_file_path);
$result = curl_exec ($ch);
curl_close ($ch);
unset($ch);
?>