Watermarking, what does it actually consist of ...

[Mikael Syska]

Hi,

On Fri, May 23, 2008 at 1:42 PM, Matt Hampton <spamlists at coders.co.uk> wrote:
>
>>> The only problem I see is converting the date in to a unix time stamp...
>>>
>>
>> Well, maybe ... dont know yet.
>>
>> So .... just to make things clear ... its a MD5 hash ... converted to
>> base64 ... and when it comes back into MailScanner again it
>> recalculates the hash ... with the info from the mail ... and then
>> compares the two string hashes ?
>> Or am I totally lost here .. ?
>>
>>
>
> Yes exactly right - the Date is calculated from the Date field *NOT* the
> system date.
> The header is actually
>
> X-MailScanner-Watermark: 1213961026.89637 at zP9SzydkvnIBOgx58U4azQ
>
>
> where the number before the @ is the expiry of the token.
>


return Digest::MD5::md5_base64(join("\$\%", $expiry, $email, $date,
$secret,$msgid));

$expiry == is what ... days from the MailScanner.Conf converted to ???
and is this also added to the hash ... ???
$email == From mail taken from the header. But converted to a Unix timestamp
$secret == From the MailScanner.Conf file
$date == also taken from the email header.
$msgid == also taken from the haeder.


so ... its joined with the $% ( the \ is escaping right ? )

like "expiry$%email$%date(timestamp)$%sescret$%msgid" and the hash is
taken from that ?

So what are the Expiry token ... ?

Sorry about these all these maybe stupid questions ... but I want to
do it right the first time ... so I'm 100% sure its the right way when
I'm trying to make the Watermark myself ... in a winblows system :-p

// ouT, Mikael Syska