feat(jwt-exp): exp claim at the access entry level

Signed-off-by: Matheus Pimenta <matheuscscp@gmail.com>

Author: matheuscscp

pkg/api/bearer.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"regexp"
 	"slices"
+	"time"
 
 	"github.com/golang-jwt/jwt/v5"
 
@@ -16,9 +17,18 @@ var bearerTokenMatch = regexp.MustCompile("(?i)bearer (.*)")
 // ResourceAccess is a single entry in the private 'access' claim specified by the distribution token authentication
 // specification.
 type ResourceAccess struct {
+	// Standard claims defined in the Distribution spec:
+	// https://distribution.github.io/distribution/spec/auth/jwt/
+
 	Type    string   `json:"type"`
 	Name    string   `json:"name"`
 	Actions []string `json:"actions"`
+
+	// Zot extensions
+
+	// ExpiresAt is an optional expiration time for this specific resource access entry.
+	// If not set, the overall token expiration time (the standard 'exp' claim) applies.
+	ExpiresAt *jwt.NumericDate `json:"exp,omitempty"`
 }
 
 type ResourceAction struct {
@@ -123,6 +133,10 @@ func (a *BearerAuthorizer) Authorize(header string, requested *ResourceAction) e
 			continue
 		}
 
+		if allowed.ExpiresAt != nil && allowed.ExpiresAt.Time.Before(time.Now()) {
+			continue
+		}
+
 		// requested action is allowed, so don't return an error
 		return nil
 	}

pkg/api/bearer_test.go

@@ -111,6 +111,155 @@ func TestBearerAuthorizer(t *testing.T) {
 			})
 		})
 
+		Convey("Access entry with per-entry ExpiresAt", func() {
+			now := time.Now()
+
+			Convey("Authorized when ExpiresAt is in the future", func() {
+				access := []api.ResourceAccess{
+					{
+						Name:      "authorized-repository",
+						Type:      "repository",
+						Actions:   []string{"pull"},
+						ExpiresAt: jwt.NewNumericDate(now.Add(time.Hour)),
+					},
+				}
+
+				claims := api.ClaimsWithAccess{
+					Access: access,
+					RegisteredClaims: jwt.RegisteredClaims{
+						ExpiresAt: jwt.NewNumericDate(now.Add(time.Hour)),
+						IssuedAt:  jwt.NewNumericDate(now),
+						Issuer:    "Zot",
+						Audience:  []string{"Zot Registry"},
+					},
+				}
+
+				token, err := jwt.NewWithClaims(signingMethod, claims).SignedString(privKey)
+				So(err, ShouldBeNil)
+
+				requested := &api.ResourceAction{
+					Type:   "repository",
+					Name:   "authorized-repository",
+					Action: "pull",
+				}
+
+				err = authorizer.Authorize("Bearer "+token, requested)
+				So(err, ShouldBeNil)
+			})
+
+			Convey("Denied when ExpiresAt is in the past", func() {
+				access := []api.ResourceAccess{
+					{
+						Name:      "authorized-repository",
+						Type:      "repository",
+						Actions:   []string{"pull"},
+						ExpiresAt: jwt.NewNumericDate(now.Add(-time.Hour)),
+					},
+				}
+
+				claims := api.ClaimsWithAccess{
+					Access: access,
+					RegisteredClaims: jwt.RegisteredClaims{
+						ExpiresAt: jwt.NewNumericDate(now.Add(time.Hour)),
+						IssuedAt:  jwt.NewNumericDate(now),
+						Issuer:    "Zot",
+						Audience:  []string{"Zot Registry"},
+					},
+				}
+
+				token, err := jwt.NewWithClaims(signingMethod, claims).SignedString(privKey)
+				So(err, ShouldBeNil)
+
+				requested := &api.ResourceAction{
+					Type:   "repository",
+					Name:   "authorized-repository",
+					Action: "pull",
+				}
+
+				err = authorizer.Authorize("Bearer "+token, requested)
+				So(err, ShouldHaveSameTypeAs, &api.AuthChallengeError{})
+				So(err, ShouldBeError, zerr.ErrInsufficientScope)
+			})
+
+			Convey("Only the expired entry is skipped, other entries still work", func() {
+				access := []api.ResourceAccess{
+					{
+						Name:      "authorized-repository",
+						Type:      "repository",
+						Actions:   []string{"pull"},
+						ExpiresAt: jwt.NewNumericDate(now.Add(-time.Hour)),
+					},
+					{
+						Name:    "authorized-repository",
+						Type:    "repository",
+						Actions: []string{"pull", "push"},
+					},
+				}
+
+				claims := api.ClaimsWithAccess{
+					Access: access,
+					RegisteredClaims: jwt.RegisteredClaims{
+						ExpiresAt: jwt.NewNumericDate(now.Add(time.Hour)),
+						IssuedAt:  jwt.NewNumericDate(now),
+						Issuer:    "Zot",
+						Audience:  []string{"Zot Registry"},
+					},
+				}
+
+				token, err := jwt.NewWithClaims(signingMethod, claims).SignedString(privKey)
+				So(err, ShouldBeNil)
+
+				requested := &api.ResourceAction{
+					Type:   "repository",
+					Name:   "authorized-repository",
+					Action: "pull",
+				}
+
+				err = authorizer.Authorize("Bearer "+token, requested)
+				So(err, ShouldBeNil)
+			})
+
+			Convey("All entries expired results in insufficient scope", func() {
+				access := []api.ResourceAccess{
+					{
+						Name:      "authorized-repository",
+						Type:      "repository",
+						Actions:   []string{"pull"},
+						ExpiresAt: jwt.NewNumericDate(now.Add(-time.Hour)),
+					},
+					{
+						Name:      "authorized-repository",
+						Type:      "repository",
+						Actions:   []string{"pull"},
+						ExpiresAt: jwt.NewNumericDate(now.Add(-2 * time.Hour)),
+					},
+				}
+
+				claims := api.ClaimsWithAccess{
+					Access: access,
+					RegisteredClaims: jwt.RegisteredClaims{
+						ExpiresAt: jwt.NewNumericDate(now.Add(time.Hour)),
+						IssuedAt:  jwt.NewNumericDate(now),
+						Issuer:    "Zot",
+						Audience:  []string{"Zot Registry"},
+					},
+				}
+
+				token, err := jwt.NewWithClaims(signingMethod, claims).SignedString(privKey)
+				So(err, ShouldBeNil)
+
+				requested := &api.ResourceAction{
+					Type:   "repository",
+					Name:   "authorized-repository",
+					Action: "pull",
+				}
+
+				err = authorizer.Authorize("Bearer "+token, requested)
+				So(err, ShouldHaveSameTypeAs, &api.AuthChallengeError{})
+				So(err, ShouldBeError, zerr.ErrInsufficientScope)
+			})
+		})
+
 		Convey("Invalid token", func() {
 			authHeader := "invalid"