manifest: validate document type before unmarshal

Signed-off-by: Samuel Karp <skarp@amazon.com>
This commit is contained in:
Samuel Karp 2021-10-21 15:09:39 -07:00
parent 6248a88d03
commit b59a6f8279
No known key found for this signature in database
GPG key ID: 7F8CDFDD70CC3D44
4 changed files with 109 additions and 0 deletions

View file

@ -54,6 +54,9 @@ func init() {
}
imageIndexFunc := func(b []byte) (distribution.Manifest, distribution.Descriptor, error) {
if err := validateIndex(b); err != nil {
return nil, distribution.Descriptor{}, err
}
m := new(DeserializedManifestList)
err := m.UnmarshalJSON(b)
if err != nil {
@ -221,3 +224,23 @@ func (m DeserializedManifestList) Payload() (string, []byte, error) {
return mediaType, m.canonical, nil
}
// unknownDocument represents a manifest, manifest list, or index that has not
// yet been validated
type unknownDocument struct {
Config interface{} `json:"config,omitempty"`
Layers interface{} `json:"layers,omitempty"`
}
// validateIndex returns an error if the byte slice is invalid JSON or if it
// contains fields that belong to a manifest
func validateIndex(b []byte) error {
var doc unknownDocument
if err := json.Unmarshal(b, &doc); err != nil {
return err
}
if doc.Config != nil || doc.Layers != nil {
return errors.New("index: expected index but found manifest")
}
return nil
}

View file

@ -7,6 +7,8 @@ import (
"testing"
"github.com/distribution/distribution/v3"
"github.com/distribution/distribution/v3/manifest/ocischema"
v1 "github.com/opencontainers/image-spec/specs-go/v1"
)
@ -327,3 +329,33 @@ func TestMediaTypes(t *testing.T) {
mediaTypeTest(t, v1.MediaTypeImageIndex, v1.MediaTypeImageIndex, false)
mediaTypeTest(t, v1.MediaTypeImageIndex, v1.MediaTypeImageIndex+"XXX", true)
}
func TestValidateManifest(t *testing.T) {
manifest := ocischema.Manifest{
Config: distribution.Descriptor{Size: 1},
Layers: []distribution.Descriptor{{Size: 2}},
}
index := ManifestList{
Manifests: []ManifestDescriptor{
{Descriptor: distribution.Descriptor{Size: 3}},
},
}
t.Run("valid", func(t *testing.T) {
b, err := json.Marshal(index)
if err != nil {
t.Fatal("unexpected error marshaling index", err)
}
if err := validateIndex(b); err != nil {
t.Error("index should be valid", err)
}
})
t.Run("invalid", func(t *testing.T) {
b, err := json.Marshal(manifest)
if err != nil {
t.Fatal("unexpected error marshaling manifest", err)
}
if err := validateIndex(b); err == nil {
t.Error("manifest should not be valid")
}
})
}

View file

@ -22,6 +22,9 @@ var (
func init() {
ocischemaFunc := func(b []byte) (distribution.Manifest, distribution.Descriptor, error) {
if err := validateManifest(b); err != nil {
return nil, distribution.Descriptor{}, err
}
m := new(DeserializedManifest)
err := m.UnmarshalJSON(b)
if err != nil {
@ -122,3 +125,22 @@ func (m *DeserializedManifest) MarshalJSON() ([]byte, error) {
func (m DeserializedManifest) Payload() (string, []byte, error) {
return v1.MediaTypeImageManifest, m.canonical, nil
}
// unknownDocument represents a manifest, manifest list, or index that has not
// yet been validated
type unknownDocument struct {
Manifests interface{} `json:"manifests,omitempty"`
}
// validateManifest returns an error if the byte slice is invalid JSON or if it
// contains fields that belong to a index
func validateManifest(b []byte) error {
var doc unknownDocument
if err := json.Unmarshal(b, &doc); err != nil {
return err
}
if doc.Manifests != nil {
return errors.New("ocimanifest: expected manifest but found index")
}
return nil
}

View file

@ -8,6 +8,8 @@ import (
"github.com/distribution/distribution/v3"
"github.com/distribution/distribution/v3/manifest"
"github.com/distribution/distribution/v3/manifest/manifestlist"
v1 "github.com/opencontainers/image-spec/specs-go/v1"
)
@ -182,3 +184,33 @@ func TestMediaTypes(t *testing.T) {
mediaTypeTest(t, v1.MediaTypeImageManifest, false)
mediaTypeTest(t, v1.MediaTypeImageManifest+"XXX", true)
}
func TestValidateManifest(t *testing.T) {
manifest := Manifest{
Config: distribution.Descriptor{Size: 1},
Layers: []distribution.Descriptor{{Size: 2}},
}
index := manifestlist.ManifestList{
Manifests: []manifestlist.ManifestDescriptor{
{Descriptor: distribution.Descriptor{Size: 3}},
},
}
t.Run("valid", func(t *testing.T) {
b, err := json.Marshal(manifest)
if err != nil {
t.Fatal("unexpected error marshaling manifest", err)
}
if err := validateManifest(b); err != nil {
t.Error("manifest should be valid", err)
}
})
t.Run("invalid", func(t *testing.T) {
b, err := json.Marshal(index)
if err != nil {
t.Fatal("unexpected error marshaling index", err)
}
if err := validateManifest(b); err == nil {
t.Error("index should not be valid")
}
})
}