title: Authenticate username/password against IDP using Spring Security SAML
body: <p>I'm aware of how SAML is used for single sign-on (SSO). That is redirection to IDP from SP and getting the user's identity from the SAML response/assertion.</p>
  
  <p><strong>My question is</strong>: Can I use Spring Security SAML framework to define how to pass username and password as part of a SAML request XML for authentication? Note that I'm not talking about single sign on and just want authentication of username/password programmatically. I am receiving that username/password as part of a web service request (in the header) and the requirement is to validate that username/password against the IDP.</p>
  
  <p>Does IDP provide any API or mechanism for authenticating the username/password that I receive as part of web service request?</p>
  
  <p>Thanks in advance!</p>