moby/api/server/middleware/authorization.go

package middleware

import (
	"net/http"

	"github.com/Sirupsen/logrus"
	"github.com/docker/docker/api/server/httputils"
	"github.com/docker/docker/pkg/authorization"
	"golang.org/x/net/context"
)

// NewAuthorizationMiddleware creates a new Authorization middleware.
func NewAuthorizationMiddleware(plugins []authorization.Plugin) Middleware {
	return func(handler httputils.APIFunc) httputils.APIFunc {
		return func(ctx context.Context, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

			user := ""
			userAuthNMethod := ""

			// Default authorization using existing TLS connection credentials
			// FIXME: Non trivial authorization mechanisms (such as advanced certificate validations, kerberos support
			// and ldap) will be extracted using AuthN feature, which is tracked under:
			// https://github.com/docker/docker/pull/20883
			if r.TLS != nil && len(r.TLS.PeerCertificates) > 0 {
				user = r.TLS.PeerCertificates[0].Subject.CommonName
				userAuthNMethod = "TLS"
			}

			authCtx := authorization.NewCtx(plugins, user, userAuthNMethod, r.Method, r.RequestURI)

			if err := authCtx.AuthZRequest(w, r); err != nil {
				logrus.Errorf("AuthZRequest for %s %s returned error: %s", r.Method, r.RequestURI, err)
				return err
			}

			rw := authorization.NewResponseModifier(w)

			if err := handler(ctx, rw, r, vars); err != nil {
				logrus.Errorf("Handler for %s %s returned error: %s", r.Method, r.RequestURI, err)
				return err
			}

			if err := authCtx.AuthZResponse(rw, r); err != nil {
				logrus.Errorf("AuthZResponse for %s %s returned error: %s", r.Method, r.RequestURI, err)
				return err
			}
			return nil
		}
	}
}