distribution/registry/auth/silly/access.go
Cory Snider bd80d7590d reg/auth: remove contexts from Authorized method
The details of how request-scoped information is propagated through the
registry server app should be left as private implementation details so
they can be changed without fear of breaking compatibility with
third-party code which imports the distribution module. The
AccessController interface unnecessarily bakes into the public API
details of how authorization grants are propagated through request
contexts. In practice the only values the in-tree authorizers attach to
the request contexts are the UserInfo and Resources for the request.
Change the AccessController interface to return the UserInfo and
Resources directly to allow us to change how request contexts are used
within the app without altering the AccessController interface contract.

Signed-off-by: Cory Snider <csnider@mirantis.com>
2023-10-27 10:58:37 -04:00

91 lines
2.6 KiB
Go

// Package silly provides a simple authentication scheme that checks for the
// existence of an Authorization header and issues access if is present and
// non-empty.
//
// This package is present as an example implementation of a minimal
// auth.AccessController and for testing. This is not suitable for any kind of
// production security.
package silly
import (
"fmt"
"net/http"
"strings"
"github.com/distribution/distribution/v3/registry/auth"
)
// accessController provides a simple implementation of auth.AccessController
// that simply checks for a non-empty Authorization header. It is useful for
// demonstration and testing.
type accessController struct {
realm string
service string
}
var _ auth.AccessController = &accessController{}
func newAccessController(options map[string]interface{}) (auth.AccessController, error) {
realm, present := options["realm"]
if _, ok := realm.(string); !present || !ok {
return nil, fmt.Errorf(`"realm" must be set for silly access controller`)
}
service, present := options["service"]
if _, ok := service.(string); !present || !ok {
return nil, fmt.Errorf(`"service" must be set for silly access controller`)
}
return &accessController{realm: realm.(string), service: service.(string)}, nil
}
// Authorized simply checks for the existence of the authorization header,
// responding with a bearer challenge if it doesn't exist.
func (ac *accessController) Authorized(req *http.Request, accessRecords ...auth.Access) (*auth.Grant, error) {
if req.Header.Get("Authorization") == "" {
challenge := challenge{
realm: ac.realm,
service: ac.service,
}
if len(accessRecords) > 0 {
var scopes []string
for _, access := range accessRecords {
scopes = append(scopes, fmt.Sprintf("%s:%s:%s", access.Type, access.Resource.Name, access.Action))
}
challenge.scope = strings.Join(scopes, " ")
}
return nil, &challenge
}
return &auth.Grant{User: auth.UserInfo{Name: "silly"}}, nil
}
type challenge struct {
realm string
service string
scope string
}
var _ auth.Challenge = challenge{}
// SetHeaders sets a simple bearer challenge on the response.
func (ch challenge) SetHeaders(r *http.Request, w http.ResponseWriter) {
header := fmt.Sprintf("Bearer realm=%q,service=%q", ch.realm, ch.service)
if ch.scope != "" {
header = fmt.Sprintf("%s,scope=%q", header, ch.scope)
}
w.Header().Set("WWW-Authenticate", header)
}
func (ch challenge) Error() string {
return fmt.Sprintf("silly authentication challenge: %#v", ch)
}
// init registers the silly auth backend.
func init() {
auth.Register("silly", auth.InitFunc(newAccessController))
}