module ActionDispatch # This middleware is added to the stack when `config.force_ssl = true`, and is passed # the options set in `config.ssl_options`. It does three jobs to enforce secure HTTP # requests: # # 1. TLS redirect: Permanently redirects http:// requests to https:// # with the same URL host, path, etc. Enabled by default. Set `config.ssl_options` # to modify the destination URL # (e.g. `redirect: { host: "secure.widgets.com", port: 8080 }`), or set # `redirect: false` to disable this feature. # # 2. Secure cookies: Sets the `secure` flag on cookies to tell browsers they # mustn't be sent along with http:// requests. Enabled by default. Set # `config.ssl_options` with `secure_cookies: false` to disable this feature. # # 3. HTTP Strict Transport Security (HSTS): Tells the browser to remember # this site as TLS-only and automatically redirect non-TLS requests. # Enabled by default. Configure `config.ssl_options` with `hsts: false` to disable. # # Set `config.ssl_options` with `hsts: { … }` to configure HSTS: # * `expires`: How long, in seconds, these settings will stick. The minimum # required to qualify for browser preload lists is `18.weeks`. Defaults to # `180.days` (recommended). # * `subdomains`: Set to `true` to tell the browser to apply these settings # to all subdomains. This protects your cookies from interception by a # vulnerable site on a subdomain. Defaults to `false`. # * `preload`: Advertise that this site may be included in browsers' # preloaded HSTS lists. HSTS protects your site on every visit *except the # first visit* since it hasn't seen your HSTS header yet. To close this # gap, browser vendors include a baked-in list of HSTS-enabled sites. # Go to https://hstspreload.appspot.com to submit your site for inclusion. # Defaults to `false`. # # To turn off HSTS, omitting the header is not enough. Browsers will remember the # original HSTS directive until it expires. Instead, use the header to tell browsers to # expire HSTS immediately. Setting `hsts: false` is a shortcut for # `hsts: { expires: 0 }`. # # Requests can opt-out of redirection with `exclude`: # # config.ssl_options = { redirect: { exclude: -> request { request.path =~ /healthcheck/ } } } class SSL # Default to 180 days, the low end for https://www.ssllabs.com/ssltest/ # and greater than the 18-week requirement for browser preload lists. HSTS_EXPIRES_IN = 15552000 def self.default_hsts_options { expires: HSTS_EXPIRES_IN, subdomains: false, preload: false } end def initialize(app, redirect: {}, hsts: {}, secure_cookies: true, **options) @app = app if options[:host] || options[:port] ActiveSupport::Deprecation.warn <<-end_warning.strip_heredoc The `:host` and `:port` options are moving within `:redirect`: `config.ssl_options = { redirect: { host: …, port: … } }`. end_warning @redirect = options.slice(:host, :port) else @redirect = redirect end @exclude = @redirect && @redirect[:exclude] || proc { !@redirect } @secure_cookies = secure_cookies if hsts != true && hsts != false && hsts[:subdomains].nil? hsts[:subdomains] = false ActiveSupport::Deprecation.warn <<-end_warning.strip_heredoc In Rails 5.1, The `:subdomains` option of HSTS config will be treated as true if unspecified. Set `config.ssl_options = { hsts: { subdomains: false } }` to opt out of this behavior. end_warning end @hsts_header = build_hsts_header(normalize_hsts_options(hsts)) end def call(env) request = Request.new env if request.ssl? @app.call(env).tap do |status, headers, body| set_hsts_header! headers flag_cookies_as_secure! headers if @secure_cookies end else return redirect_to_https request unless @exclude.call(request) @app.call(env) end end private def set_hsts_header!(headers) headers['Strict-Transport-Security'.freeze] ||= @hsts_header end def normalize_hsts_options(options) case options # Explicitly disabling HSTS clears the existing setting from browsers # by setting expiry to 0. when false self.class.default_hsts_options.merge(expires: 0) # Default to enabled, with default options. when nil, true self.class.default_hsts_options else self.class.default_hsts_options.merge(options) end end # http://tools.ietf.org/html/rfc6797#section-6.1 def build_hsts_header(hsts) value = "max-age=#{hsts[:expires].to_i}" value << "; includeSubDomains" if hsts[:subdomains] value << "; preload" if hsts[:preload] value end def flag_cookies_as_secure!(headers) if cookies = headers['Set-Cookie'.freeze] cookies = cookies.split("\n".freeze) headers['Set-Cookie'.freeze] = cookies.map { |cookie| if cookie !~ /;\s*secure\s*(;|$)/i "#{cookie}; secure" else cookie end }.join("\n".freeze) end end def redirect_to_https(request) [ @redirect.fetch(:status, 301), { 'Content-Type' => 'text/html', 'Location' => https_location_for(request) }, @redirect.fetch(:body, []) ] end def https_location_for(request) host = @redirect[:host] || request.host port = @redirect[:port] || request.port location = "https://#{host}" location << ":#{port}" if port != 80 && port != 443 location << request.fullpath location end end end