package object import ( "bytes" "crypto/ecdsa" "crypto/sha256" "github.com/nspcc-dev/neofs-api-go/pkg/container" "github.com/nspcc-dev/neofs-api-go/pkg/owner" "github.com/nspcc-dev/neofs-api-go/util/signature" "github.com/nspcc-dev/neofs-api-go/v2/object" "github.com/nspcc-dev/neofs-api-go/v2/refs" signatureV2 "github.com/nspcc-dev/neofs-api-go/v2/signature" crypto "github.com/nspcc-dev/neofs-crypto" "github.com/pkg/errors" ) // Object represents NeoFS object that provides // a convenient interface for working in isolation // from the internal structure of an object. // // Object allows to work with the object in read-only // mode as a reflection of the immutability of objects // in the system. type Object struct { rwObject } type rwObject struct { fin bool id *ID key, sig []byte cid *container.ID ownerID *owner.ID payloadChecksum *refs.Checksum payload []byte // TODO: add other fields } // Verify checks if object structure is correct. func (o *Object) Verify() error { if o == nil { return nil } hdr := o.v2Header() data, err := hdr.StableMarshal(nil) if err != nil { return errors.Wrap(err, "could not marshal header") } hdrChecksum := sha256.Sum256(data) if !bytes.Equal(hdrChecksum[:], o.id.ToV2().GetValue()) { return errors.New("invalid object identifier") } if err := signature.VerifyDataWithSource( signatureV2.StableMarshalerWrapper{ SM: o.id.ToV2(), }, func() (key, sig []byte) { return o.key, o.sig }, ); err != nil { return errors.Wrap(err, "invalid object ID signature") } return nil } // GetPayload returns object payload bytes. func (o *Object) GetPayload() []byte { if o != nil { return o.payload } return nil } // CutPayload copies object fields w/o payload. func (o *Object) CutPayload() *Object { if o != nil { return &Object{ rwObject: rwObject{ fin: o.fin, id: o.id, key: o.key, sig: o.sig, cid: o.cid, ownerID: o.ownerID, payloadChecksum: o.payloadChecksum, }, } } return nil } func (o *rwObject) v2Header() *object.Header { hV2 := new(object.Header) hV2.SetContainerID(o.cid.ToV2()) hV2.SetOwnerID(o.ownerID.ToV2()) hV2.SetPayloadHash(o.payloadChecksum) // TODO: set other fields return hV2 } func (o *rwObject) complete(key *ecdsa.PrivateKey) (*object.Header, error) { hdr := o.v2Header() hdrData, err := hdr.StableMarshal(nil) if err != nil { return nil, errors.Wrap(err, "could not marshal header") } o.id = new(ID) o.id.SetSHA256(sha256.Sum256(hdrData)) if err := signature.SignDataWithHandler( key, signatureV2.StableMarshalerWrapper{ SM: o.id.ToV2(), }, func(key []byte, sig []byte) { o.key, o.sig = key, sig }, ); err != nil { return nil, errors.Wrap(err, "could sign object identifier") } o.fin = true return hdr, nil } // ToV2 calculates object identifier, signs structure and converts // it to v2 Object message. func (o *rwObject) ToV2(key *ecdsa.PrivateKey) (*object.Object, error) { if o == nil { return nil, nil } var ( hdr *object.Header err error ) if !o.fin { if key == nil { return nil, errors.Wrap(crypto.ErrEmptyPrivateKey, "could complete the object") } if hdr, err = o.complete(key); err != nil { return nil, errors.Wrapf(err, "could not complete the object") } } else { hdr = o.v2Header() } obj := new(object.Object) obj.SetObjectID(o.id.ToV2()) obj.SetHeader(hdr) obj.SetPayload(o.payload) sig := new(refs.Signature) sig.SetKey(o.key) sig.SetSign(o.sig) obj.SetSignature(sig) return obj, nil } // FromV2 converts v2 Object message to Object instance. // // Returns any error encountered which prevented the // recovery of object data from the message. func FromV2(oV2 *object.Object) (*Object, error) { if oV2 == nil { return nil, nil } hdr := oV2.GetHeader() // TODO: convert other fields sig := oV2.GetSignature() return &Object{ rwObject: rwObject{ fin: true, id: NewIDFromV2(oV2.GetObjectID()), key: sig.GetKey(), sig: sig.GetSign(), cid: container.NewIDFromV2(hdr.GetContainerID()), ownerID: owner.NewIDFromV2(hdr.GetOwnerID()), payloadChecksum: hdr.GetPayloadHash(), payload: oV2.GetPayload(), }, }, nil } // FromBytes restores Object from a binary representation. func FromBytes(data []byte) (*Object, error) { oV2 := new(object.Object) if err := oV2.StableUnmarshal(data); err != nil { return nil, errors.Wrap(err, "could not unmarshal object") } return FromV2(oV2) }