Working with SAML(Security Assertion Markup Language) in rails by 'ruby-saml' gem

Security Assertion Markup Language (SAML, pronounced sam-el) is an XML-based, open-standard data format for exchanging authentication and authorization data between parties, in particular, between an identity provider and a service provider. SAML is a product of the OASIS Security Services Technical Committee. SAML dates from 2001; the most recent major update of SAML was published in 2005, but protocol enhancements have steadily been added through additional, optional standards.

Here is an example of implementing saml-sso in rails applications by using 'ruby-saml':

1. Install gem:

     gem install 'ruby-saml' or whrite gem 'ruby-saml' in your app's gem file.

2. Create a controller named 'saml'.

3. Configure settings:

 3.a create a yml file inside app/config/saml_settings.yml.
 3.b add the following code inside the yml file

idp:
  sso_target_url: idp_provider's_saml_auth_path
  slo_target_url: idp_provider's_saml_logout_path

so:
  assertion_consumer_service_url: Service_providers_consume_path
  issuer: service_provider's_path
  assertion_consumer_logout_service_url: service_provider's_saml_logout_path

4.Load all saml settings in your saml_controller.

5.Send login request to idp:

 def init  request = OneLogin::RubySaml::Authrequest.new
  redirect_to(request.create(saml_settings))
end

6.Handle Idp response for login:

def consume  response = OneLogin::RubySaml::Response.new(params[:SAMLResponse])
  response.settings = saml_settings
  if response.is_valid? && user = User.find_or_create_by(email: response.name_id)
    session[:user_id] = user.id
    redirect_to root_url
  else    redirect_to login_path
  end
end

the above example is for implementing single sign on in a rails app.