[xmlsec] Different digest value between .NET implementation and XmlSec?

[Chugh, Sanjay]

Title: Message

Hello, I am in the middle of learning all this business about XmlDigital signatures and Encryption.

To try and understand things, I've been trying different libraries and trying to verify results.

I have run into one issue that I was wondering if somebody could shed some light into.

I have the XML file shown at the bottom of the e-mail.

When I calculate a signature using XmlSec, the digest value generated is:

<DigestValue>UT4+z2LQyKSxNWWdS7VE8uTo+wE=</DigestValue>

However, when I calculate a signature on the same file using .NET, the digest value is different:

<DigestValue>sUD7jzvAdt3liQEkrpGsJukqftU=</DigestValue>

I have tracked it down to the following. The XmlSec library is calculating the digest on the canonicalized form without the procession instruction

 

<?xml-stylesheet type="text/xsl" href="" ?>

at the top of the file. The .NET implementation includes the processing instruction in it's calculation of the digest. According to what I have read, I believe that .NET is correct to include the processing instruction in it's calculation of the digest.

 

Does anyone know why this should be the case?

 

Thanks.

 

-- Sanjay

 

Here is the Xml file:

 

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="" ?>
<!DOCTYPE sales [
<!ELEMENT sales (region*)>
<!ATTLIST sales quarter CDATA #IMPLIED>
<!ELEMENT region (units, amount)>
<!ATTLIST region name ID #IMPLIED>
<!ELEMENT units (#PCDATA) >
<!ELEMENT amount (#PCDATA) >
]>
<sales quarter="2001-01">
   <region name="Northeast">
      <units>374</units>
      <amount>12500.26</amount>
   </region>
   <region name="Southeast">
      <units>512</units>
      <amount>17692</amount>
   </region>
   <region name="Southwest">
      <units>161</units>
      <amount>8349.72</amount>
   </region>
   <region name="Northwest">
      <units>465</units>
      <amount>15239.6</amount>
   </region>
</sales>