How to read an XML response?

[proflivio]

Slight noob alert here...

I'm trying to implement an SSO endpoint where I receive the SAML response from my IDP. How can I extract the XML data from the request body?

Edit:
Adding a few more details to clarify what I'm trying to do...

I'm trying to implement SSO in one of my apps. After a successful authorisation, my IDP sends an XML request to my ACS endpoint. I don't know where to begin looking for where the data could be hidden inside the request body.

I get a ReadableStream body, and request.body.text() returns a string beginning with 'SAMLResponse=PHNhbWxwOlJl...' (more than 6000 characters long), for which I don't know what it should represent. If I understood correctly, the response should be something similar to this:

<samlp:Response xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" ID="_8e8dc5f69a98cc4c1ff3427e5ce34606fd672f91e6" Version="2.0" IssueInstant="2014-07-17T01:01:48Z" Destination="http://sp.example.com/demo1/index.php?acs" InResponseTo="ONELOGIN_4fee3b046395c4e751011e97f8900b5273d56685">
  <saml:Issuer>http://idp.example.com/metadata.php</saml:Issuer>
  <samlp:Status>
    <samlp:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/>
  </samlp:Status>

Is there any (easy) way to exctract said data, something what ideally an imaginary request.body.xml() would do? :)

[proflivio]

Silly me, it was a base64 encoded response, but I didn't uri decode it, so I was getting gibberish. This solved it for me:

const response = decodeURIComponent((await request.text()).replace('SAMLResponse=', ''))