package schema1 import ( "encoding/json" "fmt" "github.com/docker/distribution" "github.com/docker/distribution/digest" "github.com/docker/distribution/manifest" "github.com/docker/libtrust" ) const ( // MediaTypeManifest specifies the mediaType for the current version. Note // that for schema version 1, the the media is optionally "application/json". MediaTypeManifest = "application/vnd.docker.distribution.manifest.v1+json" // MediaTypeSignedManifest specifies the mediatype for current SignedManifest version MediaTypeSignedManifest = "application/vnd.docker.distribution.manifest.v1+prettyjws" // MediaTypeManifestLayer specifies the media type for manifest layers MediaTypeManifestLayer = "application/vnd.docker.container.image.rootfs.diff+x-gtar" ) var ( // SchemaVersion provides a pre-initialized version structure for this // packages version of the manifest. SchemaVersion = manifest.Versioned{ SchemaVersion: 1, } ) func init() { schema1Func := func(b []byte) (distribution.Manifest, distribution.Descriptor, error) { sm := new(SignedManifest) err := sm.UnmarshalJSON(b) if err != nil { return nil, distribution.Descriptor{}, err } desc := distribution.Descriptor{ Digest: digest.FromBytes(sm.Canonical), Size: int64(len(sm.Canonical)), MediaType: MediaTypeManifest, } return sm, desc, err } err := distribution.RegisterManifestSchema(MediaTypeManifest, schema1Func) if err != nil { panic(fmt.Sprintf("Unable to register manifest: %s", err)) } err = distribution.RegisterManifestSchema("", schema1Func) if err != nil { panic(fmt.Sprintf("Unable to register manifest: %s", err)) } err = distribution.RegisterManifestSchema("application/json; charset=utf-8", schema1Func) if err != nil { panic(fmt.Sprintf("Unable to register manifest: %s", err)) } } // FSLayer is a container struct for BlobSums defined in an image manifest type FSLayer struct { // BlobSum is the tarsum of the referenced filesystem image layer BlobSum digest.Digest `json:"blobSum"` } // History stores unstructured v1 compatibility information type History struct { // V1Compatibility is the raw v1 compatibility information V1Compatibility string `json:"v1Compatibility"` } // Manifest provides the base accessible fields for working with V2 image // format in the registry. type Manifest struct { manifest.Versioned // Name is the name of the image's repository Name string `json:"name"` // Tag is the tag of the image specified by this manifest Tag string `json:"tag"` // Architecture is the host architecture on which this image is intended to // run Architecture string `json:"architecture"` // FSLayers is a list of filesystem layer blobSums contained in this image FSLayers []FSLayer `json:"fsLayers"` // History is a list of unstructured historical data for v1 compatibility History []History `json:"history"` } // SignedManifest provides an envelope for a signed image manifest, including // the format sensitive raw bytes. type SignedManifest struct { Manifest // Canonical is the canonical byte representation of the ImageManifest, // without any attached signatures. The manifest byte // representation cannot change or it will have to be re-signed. Canonical []byte `json:"-"` // all contains the byte representation of the Manifest including signatures // and is retuend by Payload() all []byte } // UnmarshalJSON populates a new SignedManifest struct from JSON data. func (sm *SignedManifest) UnmarshalJSON(b []byte) error { sm.all = make([]byte, len(b), len(b)) // store manifest and signatures in all copy(sm.all, b) jsig, err := libtrust.ParsePrettySignature(b, "signatures") if err != nil { return err } // Resolve the payload in the manifest. bytes, err := jsig.Payload() if err != nil { return err } // sm.Canonical stores the canonical manifest JSON sm.Canonical = make([]byte, len(bytes), len(bytes)) copy(sm.Canonical, bytes) // Unmarshal canonical JSON into Manifest object var manifest Manifest if err := json.Unmarshal(sm.Canonical, &manifest); err != nil { return err } sm.Manifest = manifest return nil } // References returnes the descriptors of this manifests references func (sm SignedManifest) References() []distribution.Descriptor { dependencies := make([]distribution.Descriptor, len(sm.FSLayers)) for i, fsLayer := range sm.FSLayers { dependencies[i] = distribution.Descriptor{ MediaType: "application/vnd.docker.container.image.rootfs.diff+x-gtar", Digest: fsLayer.BlobSum, } } return dependencies } // MarshalJSON returns the contents of raw. If Raw is nil, marshals the inner // contents. Applications requiring a marshaled signed manifest should simply // use Raw directly, since the the content produced by json.Marshal will be // compacted and will fail signature checks. func (sm *SignedManifest) MarshalJSON() ([]byte, error) { if len(sm.all) > 0 { return sm.all, nil } // If the raw data is not available, just dump the inner content. return json.Marshal(&sm.Manifest) } // Payload returns the signed content of the signed manifest. func (sm SignedManifest) Payload() (string, []byte, error) { return MediaTypeManifest, sm.all, nil } // Signatures returns the signatures as provided by // (*libtrust.JSONSignature).Signatures. The byte slices are opaque jws // signatures. func (sm *SignedManifest) Signatures() ([][]byte, error) { jsig, err := libtrust.ParsePrettySignature(sm.all, "signatures") if err != nil { return nil, err } // Resolve the payload in the manifest. return jsig.Signatures() }