md5 calculation

[NTBM]

I have a site that requires a valid md5 checksum to be given back to it in a form post, I am trying to utilize winhttp to pass the form data but need assistance with the md5 checksum.

The page source code:-

<script LANGUAGE="javascript" SRC="/md5.js" TYPE="text/javascript">
</script>
<script LANGUAGE="javascript" TYPE="text/javascript">
    function calcResponse() {
        str = Data1.value +
            Data2.value +
            Data3.value;

        Response.value = hex_md5(str);
        document.data.submit();
    }
</script>

Is there a way that I can generate the required md5 to pass back in a _WinHttpSimpleFormFill command?

Regards

[jchd]

Use of the forum search feature turns up a number of posted implementations.

Among them is the one by trancexx

[NTBM]

Thankyou for your response. i had searched and found lots of pages but not that one, thankyou.

if it helps, the important part is

Data3 = {a hidden field value that is random with each page load}

so i assume that the web enabled device is parsing the three variables to the script before submitting them.

Form Data from web device

<form NAME="Form1" ACTION="/tgi/page1.tgi" METHOD="post">
<center>
<table NAME="myTable" ALIGN="center" CELLPADDING="10" WIDTH="96%"
CELLSPACING="0">
<tr ALIGN="left" VALIGN="top">
<td COLSPAN="2"><font SIZE="2" FACE=
"Arial, Helvetica, sans-serif">Please enter Data1 &amp;
Data2.</font></td></tr>
<tr ALIGN="left" VALIGN="top">
<td><font FACE="Verdana,Arial"><font SIZE="-1">Data1</font></font></td>
<td><input TYPE="text" NAME="Data1" VALUE="" SIZE="32"
MAXLENGTH="32"></td></tr>
<tr ALIGN="left" VALIGN="top">
<td HEIGHT="46"><font FACE="Verdana,Arial"><font SIZE=
"-1">Data2</font></font></td>
<td HEIGHT="46"><input TYPE="text" NAME="Data2" VALUE=""
       SIZE="32" MAXLENGTH="32"></td></tr>
<tr ALIGN="left" VALIGN="top">
<td></td>
<td>
<p ALIGN="center"><input ONCLICK="calcResponse(); return false;"
TYPE="Submit" NAME="Submitbtn" VALUE="    OK      ">
       <input TYPE="button" NAME="Cancel" VALUE="   Cancel   "
       ONCLICK=
       "data1.value='';data1.value=''">
</p></td></tr></table></center>
<input TYPE="hidden" NAME="Challenge" VALUE=
"hS0r...."> <input TYPE="hidden" NAME="Response"
       VALUE="">
</form>

The Value of <input TYPE="hidden" NAME="Challenge"..> is random and but i can get it using winhttp

Having next to no working knowledge of java script or MD5, what i am trying to figure out is if simply adding them all together and then creating an MD5 hex hash will give an answer that the web page will accept, or do i need (if possible) to parse it to the java script of the page?