SAML token generation in SharePoint Web Part

Hi

We have a requirement where we need to access an asp.net web application, into a custom SharePoint web part.  

To achieve this we need to authenticate using the current logged in user identity. The third part web application has the user information that has been synced with AD and also have an API which accepts the SAML token for authentication. Thus we need an API to generate SAML token using the current user identity of SharePoint.

Does any one have any idea how this can be achieved??