[xmlsec] Trusted Root Cert source?

[Moultrie, Ferrell (ISSAtlanta)]

  How does one go about getting a list of "standard" trusted root certs
(e.g., Verisign, Thawte, Entrust, etc.) that can be used to validate a
public key certificate included with a signed document? Obviously there
is an issue of who do you trust here -- but assuming for these purposes
you trust all the CA's listed above (and probably other commercial CAs),
what is the standard way of obtaining the CA certs and then
building/loading the list of trusted root certs that are acceptible for
x509 cert verification? Is there a standard repository of such certs or
do I have to go to each CA in turn and get their current root cert for
inclusion?
Thanks!
  Ferrell

----------------------------------------------------------------
Ferrell Moultrie
  Home-      (770)552-0486   Fax- (770)552-0489  ferrell at moultrie.org
  Work[ISS]- (404)236-2849   Fax- (404)236-2609  FMoultrie at iss.net