Test if container blob is accessible before mounting (#22759) (#25783)

Backport #22759 by @KN4CK3R

related #16865

This PR adds an accessibility check before mounting container blobs.

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: silverwind <me@silverwind.io>
(cherry picked from commit 5bfe469821)

models/packages/package_blob.go

@@ -5,11 +5,18 @@ package packages
 
 import (
 	"context"
+	"strconv"
 	"time"
 
 	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/perm"
+	"code.gitea.io/gitea/models/unit"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
 	"code.gitea.io/gitea/modules/util"
+
+	"xorm.io/builder"
 )
 
 // ErrPackageBlobNotExist indicates a package blob not exist error
@@ -98,3 +105,42 @@ func GetTotalUnreferencedBlobSize(ctx context.Context) (int64, error) {
 		Where("package_file.id IS NULL").
 		SumInt(&PackageBlob{}, "size")
 }
+
+// IsBlobAccessibleForUser tests if the user has access to the blob
+func IsBlobAccessibleForUser(ctx context.Context, blobID int64, user *user_model.User) (bool, error) {
+	if user.IsAdmin {
+		return true, nil
+	}
+
+	maxTeamAuthorize := builder.
+		Select("max(team.authorize)").
+		From("team").
+		InnerJoin("team_user", "team_user.team_id = team.id").
+		Where(builder.Eq{"team_user.uid": user.ID}.And(builder.Expr("team_user.org_id = `user`.id")))
+
+	maxTeamUnitAccessMode := builder.
+		Select("max(team_unit.access_mode)").
+		From("team").
+		InnerJoin("team_user", "team_user.team_id = team.id").
+		InnerJoin("team_unit", "team_unit.team_id = team.id").
+		Where(builder.Eq{"team_user.uid": user.ID, "team_unit.type": unit.TypePackages}.And(builder.Expr("team_user.org_id = `user`.id")))
+
+	cond := builder.Eq{"package_blob.id": blobID}.And(
+		// owner = user
+		builder.Eq{"`user`.id": user.ID}.
+			// user can see owner
+			Or(builder.Eq{"`user`.visibility": structs.VisibleTypePublic}.Or(builder.Eq{"`user`.visibility": structs.VisibleTypeLimited})).
+			// owner is an organization and user has access to it
+			Or(builder.Eq{"`user`.type": user_model.UserTypeOrganization}.
+				And(builder.Lte{strconv.Itoa(int(perm.AccessModeRead)): maxTeamAuthorize}.Or(builder.Lte{strconv.Itoa(int(perm.AccessModeRead)): maxTeamUnitAccessMode}))),
+	)
+
+	return db.GetEngine(ctx).
+		Table("package_blob").
+		Join("INNER", "package_file", "package_file.blob_id = package_blob.id").
+		Join("INNER", "package_version", "package_version.id = package_file.version_id").
+		Join("INNER", "package", "package.id = package_version.package_id").
+		Join("INNER", "user", "`user`.id = package.owner_id").
+		Where(cond).
+		Exist(&PackageBlob{})
+}

routers/api/packages/container/container.go

@@ -203,6 +203,13 @@ func InitiateUploadBlob(ctx *context.Context) {
 			Digest:     mount,
 		})
 		if blob != nil {
+			accessible, err := packages_model.IsBlobAccessibleForUser(ctx, blob.Blob.ID, ctx.Doer)
+			if err != nil {
+				apiError(ctx, http.StatusInternalServerError, err)
+				return
+			}
+
+			if accessible {
 				if err := mountBlob(&packages_service.PackageInfo{Owner: ctx.Package.Owner, Name: image}, blob.Blob); err != nil {
 					apiError(ctx, http.StatusInternalServerError, err)
 					return
@@ -216,6 +223,7 @@ func InitiateUploadBlob(ctx *context.Context) {
 				return
 			}
 		}
+	}
 
 	digest := ctx.FormTrim("digest")
 	if digest != "" {

tests/integration/api_packages_container_test.go

@@ -34,6 +34,7 @@ func TestPackageContainer(t *testing.T) {
 	user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
 	session := loginUser(t, user.Name)
 	token := getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeReadPackage)
+	privateUser := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 31})
 
 	has := func(l packages_model.PackagePropertyList, name string) bool {
 		for _, pp := range l {
@@ -262,7 +263,16 @@ func TestPackageContainer(t *testing.T) {
 			t.Run("UploadBlob/Mount", func(t *testing.T) {
 				defer tests.PrintCurrentTest(t)()
 
-				req := NewRequest(t, "POST", fmt.Sprintf("%s/blobs/uploads?mount=%s", url, unknownDigest))
+				privateBlobDigest := "sha256:6ccce4863b70f258d691f59609d31b4502e1ba5199942d3bc5d35d17a4ce771d"
+				req := NewRequestWithBody(t, "POST", fmt.Sprintf("%sv2/%s/%s/blobs/uploads?digest=%s", setting.AppURL, privateUser.Name, image, privateBlobDigest), strings.NewReader("gitea"))
+				req = AddBasicAuthHeader(req, privateUser.Name)
+				MakeRequest(t, req, http.StatusCreated)
+
+				req = NewRequest(t, "POST", fmt.Sprintf("%s/blobs/uploads?mount=%s", url, unknownDigest))
+				addTokenAuthHeader(req, userToken)
+				MakeRequest(t, req, http.StatusAccepted)
+
+				req = NewRequest(t, "POST", fmt.Sprintf("%s/blobs/uploads?mount=%s", url, privateBlobDigest))
 				addTokenAuthHeader(req, userToken)
 				MakeRequest(t, req, http.StatusAccepted)