Move API OIDC/OAuth2 support from API to ManageIQ core

app/models/authenticator/httpd.rb

@@ -1,5 +1,9 @@
+require_dependency 'authenticator/httpd_oauth2'
+
 module Authenticator
   class Httpd < Base
+    include HttpdOauth2
+
     def self.proper_name
       'External httpd'
     end
@@ -25,9 +29,15 @@ def user_authorizable_without_authentication?
       true
     end
 
-    def _authenticate(_username, _password, request)
-      request.present? &&
-        request.headers['X-REMOTE-USER'].present?
+    def _authenticate(username, password, request)
+      if !user_data_collected?(request) && request.present? && oidc_configured?
+        if password.present?
+          oidc_authenticate(username, password, request)
+        else
+          authenticate_with_jwt(request)
+        end
+      end
+      user_data_collected?(request)
     end
 
     def failure_reason(_username, request)
@@ -157,5 +167,9 @@ def user_attrs_from_external_directory_via_dbus_api_service(username)
 
       HttpdDBusApi.new.user_attrs(username, ATTRS_NEEDED)
     end
+
+    def user_data_collected?(request)
+      request.present? && request.headers['X-REMOTE-USER'].present?
+    end
   end
 end

app/models/authenticator/httpd_oauth2.rb

@@ -0,0 +1,162 @@
+module HttpdOauth2
+  class HttpdOauth2Error < StandardError; end
+
+  require "net/http"
+  require "uri"
+
+  REMOTE_HEADERS =
+    {
+      "X-REMOTE-USER"           => "preferred_username",
+      "X-REMOTE-USER-EMAIL"     => "email",
+      "X-REMOTE-USER-FIRSTNAME" => "given_name",
+      "X-REMOTE-USER-LASTNAME"  => "family_name",
+      "X-REMOTE-USER-FULLNAME"  => "name",
+      "X-REMOTE-USER-GROUPS"    => "groups",
+      "X-REMOTE-USER-DOMAIN"    => "domain"
+    }.freeze
+
+  HTTPD_OPENIDC_CONF = Pathname.new("/etc/httpd/conf.d/manageiq-external-auth-openidc.conf").freeze
+
+  def oidc_configured?
+    config[:mode] == "httpd" && config[:provider_type] == "oidc" && config[:oidc_enabled] == true
+  end
+
+  def authenticate_with_jwt(request)
+    jwt_token = get_jwt_token_from_headers(request)
+    token_info = introspect_jwt_token(jwt_token)
+    define_jwt_request_headers(token_info, request)
+  rescue => e
+    raise HttpdOauth2Error, "Failed to Authenticate with JWT - error #{e}"
+  end
+
+  def oidc_authenticate(username, password, request)
+    user_jwt   = get_jwt_token_from_oidc(username, password)
+    token_info = introspect_jwt_token(user_jwt)
+    define_jwt_request_headers(token_info, request)
+  end
+
+  def httpd_oidc_config
+    @httpd_oidc_config ||= HTTPD_OPENIDC_CONF.readlines.collect(&:chomp)
+  end
+
+  def httpd_oidc_config_param(name)
+    param_spec = httpd_oidc_config.find { |line| line =~ /^#{name} .*/i }
+    return "" if param_spec.blank?
+
+    param_match = param_spec.match(/^#{name} (.*)/i)
+    param_match ? param_match[1].strip : ""
+  end
+
+  def oidc_provider_metadata
+    @oidc_provider_metadata ||= begin
+      oidc_provider_metadata_url = httpd_oidc_config_param("OIDCProviderMetadataURL")
+      if oidc_provider_metadata_url.blank?
+        {}
+      else
+        uri = URI.parse(oidc_provider_metadata_url)
+        http = Net::HTTP.new(uri.host, uri.port)
+        http.use_ssl = (uri.scheme == "https")
+        response = http.request(Net::HTTP::Get.new(uri.request_uri))
+        JSON.parse(response.body)
+      end
+    end
+  end
+
+  def oidc_metadata_url_endpoint(oidc_param, metadata_url_key)
+    endpoint = httpd_oidc_config_param(oidc_param)
+    endpoint = oidc_provider_metadata[metadata_url_key] if endpoint.blank?
+    raise HttpdOauth2Error, "Invalid #{HTTPD_OPENIDC_CONF} configuration, missing #{oidc_param} or OIDCProviderMetadataURL #{metadata_url_key} entry" if endpoint.blank?
+
+    endpoint
+  end
+
+  def oidc_token_endpoint
+    @oidc_token_endpoint ||= oidc_metadata_url_endpoint("OIDCProviderTokenEndpoint", "token_endpoint")
+  end
+
+  def oidc_token_introspection_endpoint
+    @oidc_token_introspection_endpoint ||= oidc_metadata_url_endpoint("OIDCOAuthIntrospectionEndpoint", "token_introspection_endpoint")
+  end
+
+  def oidc_client_id
+    @oidc_client_id ||= httpd_oidc_config_param("OIDCClientId")
+  end
+
+  def oidc_client_secret
+    @oidc_client_secret ||= httpd_oidc_config_param("OIDCClientSecret")
+  end
+
+  def oidc_scope
+    @oidc_scope ||= httpd_oidc_config_param("OIDCScope")
+  end
+
+  def get_jwt_token_from_headers(request)
+    jwt_token_match = request.headers["HTTP_AUTHORIZATION"].match(/^Bearer (.*)/)
+    jwt_token_match[1] if jwt_token_match
+  end
+
+  def get_jwt_token_from_oidc(username, password)
+    uri = URI.parse(oidc_token_endpoint)
+    request_params = {
+      "grant_type" => "password",
+      "username"   => username,
+      "password"   => password
+    }
+    request_params["scope"] = oidc_scope if oidc_scope.present?
+
+    post_request = Net::HTTP::Post.new(uri)
+    post_request.basic_auth(oidc_client_id, oidc_client_secret)
+    post_request.form_data = request_params
+
+    http_params     = {:use_ssl => (uri.scheme == "https")}
+    response        = Net::HTTP.start(uri.hostname, uri.port, http_params) { |http| http.request(post_request) }
+    parsed_response = JSON.parse(response.body)
+    raise HttpdOauth2Error, parsed_response["error_description"] if parsed_response["error"].present?
+
+    parsed_response["access_token"]
+  rescue => e
+    raise HttpdOauth2Error, "Failed to get a JWT Token for user #{username} - error #{e}"
+  end
+
+  def introspect_jwt_token(jwt_token)
+    uri = URI.parse(oidc_token_introspection_endpoint)
+    request_params = {
+      "token" => jwt_token
+    }
+    request_params["scope"] = oidc_scope if oidc_scope.present?
+
+    post_request = Net::HTTP::Post.new(uri)
+    post_request.basic_auth(oidc_client_id, oidc_client_secret)
+    post_request.form_data = request_params
+
+    http_params     = {:use_ssl => (uri.scheme == "https")}
+    response        = Net::HTTP.start(uri.hostname, uri.port, http_params) { |http| http.request(post_request) }
+    parsed_response = JSON.parse(response.body)
+
+    raise HttpdOauth2Error, "Invalid access token, JWT is inactive" if parsed_response["active"] != true
+
+    parsed_response
+  rescue => e
+    raise HttpdOauth2Error, "Failed to Validate the JWT - error #{e}"
+  end
+
+  def define_jwt_request_headers(token_info, request)
+    REMOTE_HEADERS.each do |rh, val|
+      request.headers[rh] = token_info[val]
+    end
+
+    if request.headers["X-REMOTE-USER-GROUPS"].present?
+      request.headers["X-REMOTE-USER-GROUPS"] = request.headers["X-REMOTE-USER-GROUPS"].join(",")
+    end
+
+    debug_headers(request)
+  end
+
+  def debug_headers(request)
+    return unless $log.debug?
+
+    REMOTE_HEADERS.keys.each do |rh|
+      $audit_log.info("request.headers[#{rh}] ->#{request.headers[rh]}<-")
+    end
+  end
+end