[SOLVED] Canonicalization of an XML document in PHP

Canonicalization of an XML document in PHP

I am trying to canonicalize an XML document in PHP.

Here is the XML document:

<?xml version="1.0" encoding="ISO-8859-1"?>
<Envelope xmlns="http://example.org/envelope">
  <Body>
    Olá mundo
  </Body>
</Envelope>

its an example from https://www.di-mgt.com.au/xmldsig2.html#twotypes.

the expected hash value is :

516b984d8ba0d7427593984a7e89f1b6182b011f

What I did in PHP :

<?php
header('Content-Type: text/plain');
$xml = new DOMDocument( "1.0", "utf-8" );
$string = '<Envelope xmlns="http://example.org/envelope">
<Body>
  Olá mundo
</Body>
</Envelope>'; 
$xml->loadXML($string);
$xml = $xml->C14N();
echo hash('sha1', $xml);
?>

however, the hash value is :

0ae2e4b4834d3a31447c50a3905669520be2bc73

Solution

Whitesapace it's important when doing C14N. XML sample is missing some of that in both the plain XML and PHP code.
Adding the missing withespace the sha1sum is correct

$string = '<Envelope xmlns="http://example.org/envelope">
  <Body>
    Olá mundo
  </Body>
  
</Envelope>';

Whitespace as shown on the provided URL

<Envelope xmlns="http://example.org/envelope">¶
♦♦<Body>¶
♦♦♦♦Olá mundo¶
♦♦</Body>¶
♦♦¶
</Envelope>