7 files changed, 131 insertions, 2 deletions
diff --git a/app/domain/entity.go b/app/domain/entity.go
index fb1cab8..0377c51 100644
--- a/app/domain/entity.go
+++ b/app/domain/entity.go
@@ -1,7 +1,6 @@
 package domain
 
 type Entity interface {
-	GetID() ID
-	SetID(id ID) error
+	Identifiable
 	Validate() error
 }
diff --git a/app/domain/identifiable.go b/app/domain/identifiable.go
new file mode 100644
index 0000000..8fbc1e4
--- /dev/null
+++ b/app/domain/identifiable.go
@@ -0,0 +1,7 @@
+package domain
+
+type Identifiable interface {
+	GetID() ID
+	SetID(id ID) error
+	ToGID() string
+}
diff --git a/app/domain/sparkle.go b/app/domain/sparkle.go
index 68aed67..d4f70b2 100644
--- a/app/domain/sparkle.go
+++ b/app/domain/sparkle.go
@@ -49,6 +49,10 @@ func (s *Sparkle) SetID(id ID) error {
 	return nil
 }
 
+func (s *Sparkle) ToGID() string {
+	return "gid://sparkle/Sparkle/" + s.ID.String()
+}
+
 func (s *Sparkle) Validate() error {
 	if s.Sparklee == "" {
 		return SparkleeIsRequired
diff --git a/app/domain/user.go b/app/domain/user.go
index aae17f6..02ddd26 100644
--- a/app/domain/user.go
+++ b/app/domain/user.go
@@ -32,3 +32,7 @@ func (self *User) Sparkle(sparklee string, reason string) *Sparkle {
 		Reason:   reason,
 	}
 }
+
+func (self *User) ToGID() string {
+	return "gid://sparkle/User/" + self.ID.String()
+}
diff --git a/app/middleware/permission.go b/app/middleware/permission.go
new file mode 100644
index 0000000..03e7cf9
--- /dev/null
+++ b/app/middleware/permission.go
@@ -0,0 +1,24 @@
+package middleware
+
+import (
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/authzd.git/pkg/rpc"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/app/domain"
+)
+
+type Permission string
+
+func (p Permission) ToGID() string {
+	return "gid://sparkle/Permission/" + p.String()
+}
+
+func (p Permission) RequestFor(user domain.Identifiable, resource domain.Identifiable) *rpc.AllowRequest {
+	return &rpc.AllowRequest{
+		Subject:    user.ToGID(),
+		Permission: p.ToGID(),
+		Resource:   resource.ToGID(),
+	}
+}
+
+func (p Permission) String() string {
+	return string(p)
+}
diff --git a/app/middleware/require_permission.go b/app/middleware/require_permission.go
new file mode 100644
index 0000000..563278e
--- /dev/null
+++ b/app/middleware/require_permission.go
@@ -0,0 +1,33 @@
+package middleware
+
+import (
+	"net/http"
+
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/authzd.git/pkg/rpc"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/app/cfg"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/app/domain"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/pkg/pls"
+)
+
+func RequirePermission(permission Permission, ability rpc.Ability) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			user := cfg.CurrentUser.From(r.Context())
+
+			reply, err := ability.Allowed(r.Context(),
+				permission.RequestFor(user, &domain.Sparkle{ID: "*"}),
+			)
+			if err != nil {
+				pls.LogError(r.Context(), err)
+				w.WriteHeader(http.StatusForbidden)
+				return
+			}
+
+			if reply.Result {
+				next.ServeHTTP(w, r)
+			} else {
+				w.WriteHeader(http.StatusForbidden)
+			}
+		})
+	}
+}
diff --git a/app/middleware/require_permission_test.go b/app/middleware/require_permission_test.go
new file mode 100644
index 0000000..34a04a7
--- /dev/null
+++ b/app/middleware/require_permission_test.go
@@ -0,0 +1,58 @@
+package middleware
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/xlgmokha/x/pkg/test"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/authzd.git/pkg/rpc"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/app/cfg"
+	"gitlab.com/gitlab-org/software-supply-chain-security/authorization/sparkled/app/domain"
+)
+
+type MockAbility func(context.Context, *rpc.AllowRequest) (*rpc.AllowReply, error)
+
+func (m MockAbility) Allowed(ctx context.Context, r *rpc.AllowRequest) (*rpc.AllowReply, error) {
+	return m(ctx, r)
+}
+
+func TestRequirePermission(t *testing.T) {
+	user := &domain.User{ID: domain.ID("1")}
+	ctx := cfg.CurrentUser.With(t.Context(), user)
+	permission := Permission("read_sparkles")
+
+	t.Run("when the permission is granted", func(t *testing.T) {
+		r, w := test.RequestResponse("GET", "/sparkles", test.WithContext(ctx))
+
+		middleware := RequirePermission(permission, MockAbility(func(ctx context.Context, r *rpc.AllowRequest) (*rpc.AllowReply, error) {
+			require.Equal(t, "gid://sparkle/User/"+user.ID.String(), r.Subject)
+			require.Equal(t, permission.ToGID(), r.Permission)
+			require.Equal(t, "gid://sparkle/Sparkle/*", r.Resource)
+
+			return &rpc.AllowReply{Result: true}, nil
+		}))
+		server := middleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.WriteHeader(http.StatusTeapot)
+		}))
+		server.ServeHTTP(w, r)
+
+		require.Equal(t, http.StatusTeapot, w.Code)
+	})
+
+	t.Run("when the permission is denied", func(t *testing.T) {
+		r, w := test.RequestResponse("GET", "/sparkles", test.WithContext(ctx))
+
+		middleware := RequirePermission(permission, MockAbility(func(ctx context.Context, r *rpc.AllowRequest) (*rpc.AllowReply, error) {
+			return &rpc.AllowReply{Result: false}, nil
+		}))
+		server := middleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			require.Fail(t, "unexpected call to handler")
+		}))
+
+		server.ServeHTTP(w, r)
+
+		require.Equal(t, http.StatusForbidden, w.Code)
+	})
+}