Hi ,
I am new to SAML.I have application where user login with user id and password. Now my application want to integrate with 3rd party application(Support SAML Authentication) using SSO . Now my question is can my existing ASP.NET application configured as IDP so when we click a button in application to call to 3rd party application (which will act as SP) , SP will make a call to my existing application(where the button was clicked) as IDP and after authorization user can login in 3rd party system without login .
What you describe is IdP-initiated SSO with your application acting as the IdP and the 3rd party application acting as the SP.
When the user clicks a button to SSO to the SP, you would call the SAML API SAMLIdentityProvider.InitiateSSO. This creates and sends a SAML response containing a SAML assertion to the SP.
I suggest taking a look at the ExampleIdentityProvider project under the Examples\SSO\WebForms folder. This demonstrates calling SAMLIdentityProvider.InitiateSSO. The Examples Guide in the documentation folder walks you through this example.
Your application would make the same call to SAMLIdentityProvider.InitiateSSO. You will also need a saml.config file similar to that of the ExampleIdentityProvider but specific to your environment.
Please note that no call is made by the SP to the IdP when using IdP-initiated SSO.