title: API for validating user credentials (username/password) in PING
body: <p>Is there an API in Ping Federate/ Ping One to validate user credentials - username and password?</p>
  <p>Here is a scenario in which I would like to use it:</p>
  <ol>
  <li>user logs in via SAML SSO to my web application</li>
  <li>certain application feature requires that the user credentials are validated again (to sign-off some operation)</li>
  </ol>
  <p>SAML SSO does not make it easy to re-validate user credentials without logging out from application, users passwords are obviously not stored in the application so the only way to validate credentials is to send them via some API to Ping to validate - however I was unable to find such API in Ping.</p>
  <p>For example, OKTA (which offers similar services as Ping) does provide such API:</p>
  <pre><code>curl -v -X POST \
  -H &quot;Accept: application/json&quot; \
  -H &quot;Content-Type: application/json&quot; \
  -d '{
    &quot;username&quot;: &quot;dade.murphy@example.com&quot;,
    &quot;password&quot;: &quot;correcthorsebatterystaple&quot;
  }' &quot;https://${yourOktaDomain}/api/v1/authn&quot;
  </code></pre>
  <p>I am looking for something similar in Ping.</p>