Move auth package under registry package

Signed-off-by: Stephen J Day <stephen.day@docker.com>

docs/auth/silly/access.go

@@ -0,0 +1,96 @@
+// 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/docker/distribution/registry/auth"
+	ctxu "github.com/docker/distribution/context"
+	"golang.org/x/net/context"
+)
+
+// 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(ctx context.Context, accessRecords ...auth.Access) (context.Context, error) {
+	req, err := ctxu.GetRequest(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	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 context.WithValue(ctx, "auth.user", auth.UserInfo{Name: "silly"}), nil
+}
+
+type challenge struct {
+	realm   string
+	service string
+	scope   string
+}
+
+func (ch *challenge) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	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("Authorization", header)
+	w.WriteHeader(http.StatusUnauthorized)
+}
+
+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))
+}