• From: David Carlisle <d.p.carlisle@g...>
• To: "Costello, Roger L." <costello@m...>
• Date: Mon, 29 Jun 2015 21:03:42 +0100

On 29 June 2015 at 19:37, Costello, Roger L. <costello@m...> wrote:
> Hi Folks,

> Should schema validation ever be done using schemas that are not local?
>
> /Roger


There isn't really any notion of local, you can only specify a
(possibly relative) URI.

Whether you have a relative or absolute URI it still (in most
frameworks) passes through
a configurable URI resolver that can return anything it wants for any URI.

At some point you have to trust something.

And why pick on schema validation for this question?
the XML document that you are validating has in many cases come from a similar
URI resolution process, so if you don't trust your URI resolver you
are validating
unknown input with an unknown schema.

David

• References:
  • Should schemas fetched via an HTTP redirect be trusted?
    • From: "Costello, Roger L." <costello@m...>