130 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			Ruby
		
	
	
	
			
		
		
	
	
			130 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			Ruby
		
	
	
	
# A dumb middleware that returns a Go HTML document if the go-get=1 query string
 | 
						|
# is used irrespective if the namespace/project exists
 | 
						|
module Gitlab
 | 
						|
  module Middleware
 | 
						|
    class Go
 | 
						|
      include ActionView::Helpers::TagHelper
 | 
						|
 | 
						|
      PROJECT_PATH_REGEX = %r{\A(#{Gitlab::PathRegex.full_namespace_route_regex}/#{Gitlab::PathRegex.project_route_regex})/}.freeze
 | 
						|
 | 
						|
      def initialize(app)
 | 
						|
        @app = app
 | 
						|
      end
 | 
						|
 | 
						|
      def call(env)
 | 
						|
        request = Rack::Request.new(env)
 | 
						|
 | 
						|
        render_go_doc(request) || @app.call(env)
 | 
						|
      end
 | 
						|
 | 
						|
      private
 | 
						|
 | 
						|
      def render_go_doc(request)
 | 
						|
        return unless go_request?(request)
 | 
						|
 | 
						|
        path = project_path(request)
 | 
						|
        return unless path
 | 
						|
 | 
						|
        body = go_body(path)
 | 
						|
        return unless body
 | 
						|
 | 
						|
        response = Rack::Response.new(body, 200, { 'Content-Type' => 'text/html' })
 | 
						|
        response.finish
 | 
						|
      end
 | 
						|
 | 
						|
      def go_request?(request)
 | 
						|
        request["go-get"].to_i == 1 && request.env["PATH_INFO"].present?
 | 
						|
      end
 | 
						|
 | 
						|
      def go_body(path)
 | 
						|
        config = Gitlab.config
 | 
						|
        project_url = URI.join(config.gitlab.url, path)
 | 
						|
        import_prefix = strip_url(project_url.to_s)
 | 
						|
 | 
						|
        repository_url = if Gitlab::CurrentSettings.enabled_git_access_protocol == 'ssh'
 | 
						|
                           shell = config.gitlab_shell
 | 
						|
                           port = ":#{shell.ssh_port}" unless shell.ssh_port == 22
 | 
						|
                           "ssh://#{shell.ssh_user}@#{shell.ssh_host}#{port}/#{path}.git"
 | 
						|
                         else
 | 
						|
                           "#{project_url}.git"
 | 
						|
                         end
 | 
						|
 | 
						|
        meta_tag = tag :meta, name: 'go-import', content: "#{import_prefix} git #{repository_url}"
 | 
						|
        head_tag = content_tag :head, meta_tag
 | 
						|
        content_tag :html, head_tag
 | 
						|
      end
 | 
						|
 | 
						|
      def strip_url(url)
 | 
						|
        url.gsub(%r{\Ahttps?://}, '')
 | 
						|
      end
 | 
						|
 | 
						|
      def project_path(request)
 | 
						|
        path_info = request.env["PATH_INFO"]
 | 
						|
        path_info.sub!(%r{^/}, '')
 | 
						|
 | 
						|
        project_path_match = "#{path_info}/".match(PROJECT_PATH_REGEX)
 | 
						|
        return unless project_path_match
 | 
						|
 | 
						|
        path = project_path_match[1]
 | 
						|
 | 
						|
        # Go subpackages may be in the form of `namespace/project/path1/path2/../pathN`.
 | 
						|
        # In a traditional project with a single namespace, this would denote repo
 | 
						|
        # `namespace/project` with subpath `path1/path2/../pathN`, but with nested
 | 
						|
        # groups, this could also be `namespace/project/path1` with subpath
 | 
						|
        # `path2/../pathN`, for example.
 | 
						|
 | 
						|
        # We find all potential project paths out of the path segments
 | 
						|
        path_segments = path.split('/')
 | 
						|
        simple_project_path = path_segments.first(2).join('/')
 | 
						|
 | 
						|
        # If the path is at most 2 segments long, it is a simple `namespace/project` path and we're done
 | 
						|
        return simple_project_path if path_segments.length <= 2
 | 
						|
 | 
						|
        project_paths = []
 | 
						|
        begin
 | 
						|
          project_paths << path_segments.join('/')
 | 
						|
          path_segments.pop
 | 
						|
        end while path_segments.length >= 2
 | 
						|
 | 
						|
        # We see if a project exists with any of these potential paths
 | 
						|
        project = project_for_paths(project_paths, request)
 | 
						|
 | 
						|
        if project
 | 
						|
          # If a project is found and the user has access, we return the full project path
 | 
						|
          project.full_path
 | 
						|
        else
 | 
						|
          # If not, we return the first two components as if it were a simple `namespace/project` path,
 | 
						|
          # so that we don't reveal the existence of a nested project the user doesn't have access to.
 | 
						|
          # This means that for an unauthenticated request to `group/subgroup/project/subpackage`
 | 
						|
          # for a private `group/subgroup/project` with subpackage path `subpackage`, GitLab will respond
 | 
						|
          # as if the user is looking for project `group/subgroup`, with subpackage path `project/subpackage`.
 | 
						|
          # Since `go get` doesn't authenticate by default, this means that
 | 
						|
          # `go get gitlab.com/group/subgroup/project/subpackage` will not work for private projects.
 | 
						|
          # `go get gitlab.com/group/subgroup/project.git/subpackage` will work, since Go is smart enough
 | 
						|
          # to figure that out. `import 'gitlab.com/...'` behaves the same as `go get`.
 | 
						|
          simple_project_path
 | 
						|
        end
 | 
						|
      end
 | 
						|
 | 
						|
      def project_for_paths(paths, request)
 | 
						|
        project = Project.where_full_path_in(paths).first
 | 
						|
        return unless Ability.allowed?(current_user(request), :read_project, project)
 | 
						|
 | 
						|
        project
 | 
						|
      end
 | 
						|
 | 
						|
      def current_user(request)
 | 
						|
        authenticator = Gitlab::Auth::RequestAuthenticator.new(request)
 | 
						|
        user = authenticator.find_user_from_access_token || authenticator.find_user_from_warden
 | 
						|
 | 
						|
        return unless user&.can?(:access_api)
 | 
						|
 | 
						|
        # Right now, the `api` scope is the only one that should be able to determine private project existence.
 | 
						|
        return unless authenticator.valid_access_token?(scopes: [:api])
 | 
						|
 | 
						|
        user
 | 
						|
      end
 | 
						|
    end
 | 
						|
  end
 | 
						|
end
 |