[#64] object: move package from neofs-api-go

Also, remove deprecated method.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

object/fmt.go

@@ -0,0 +1,175 @@
+package object
+
+import (
+	"crypto/ecdsa"
+	"crypto/sha256"
+	"errors"
+	"fmt"
+
+	signatureV2 "github.com/nspcc-dev/neofs-api-go/v2/signature"
+	"github.com/nspcc-dev/neofs-sdk-go/checksum"
+	"github.com/nspcc-dev/neofs-sdk-go/signature"
+	sigutil "github.com/nspcc-dev/neofs-sdk-go/util/signature"
+)
+
+var errCheckSumMismatch = errors.New("payload checksum mismatch")
+
+var errIncorrectID = errors.New("incorrect object identifier")
+
+// CalculatePayloadChecksum calculates and returns checksum of
+// object payload bytes.
+func CalculatePayloadChecksum(payload []byte) *checksum.Checksum {
+	res := checksum.New()
+	res.SetSHA256(sha256.Sum256(payload))
+
+	return res
+}
+
+// CalculateAndSetPayloadChecksum calculates checksum of current
+// object payload and writes it to the object.
+func CalculateAndSetPayloadChecksum(obj *RawObject) {
+	obj.SetPayloadChecksum(
+		CalculatePayloadChecksum(obj.Payload()),
+	)
+}
+
+// VerifyPayloadChecksum checks if payload checksum in the object
+// corresponds to its payload.
+func VerifyPayloadChecksum(obj *Object) error {
+	actual := CalculatePayloadChecksum(obj.Payload())
+	if !checksum.Equal(obj.PayloadChecksum(), actual) {
+		return errCheckSumMismatch
+	}
+
+	return nil
+}
+
+// CalculateID calculates identifier for the object.
+func CalculateID(obj *Object) (*ID, error) {
+	data, err := obj.ToV2().GetHeader().StableMarshal(nil)
+	if err != nil {
+		return nil, err
+	}
+
+	id := NewID()
+	id.SetSHA256(sha256.Sum256(data))
+
+	return id, nil
+}
+
+// CalculateAndSetID calculates identifier for the object
+// and writes the result to it.
+func CalculateAndSetID(obj *RawObject) error {
+	id, err := CalculateID(obj.Object())
+	if err != nil {
+		return err
+	}
+
+	obj.SetID(id)
+
+	return nil
+}
+
+// VerifyID checks if identifier in the object corresponds to
+// its structure.
+func VerifyID(obj *Object) error {
+	id, err := CalculateID(obj)
+	if err != nil {
+		return err
+	}
+
+	if !id.Equal(obj.ID()) {
+		return errIncorrectID
+	}
+
+	return nil
+}
+
+func CalculateIDSignature(key *ecdsa.PrivateKey, id *ID) (*signature.Signature, error) {
+	sig := signature.New()
+
+	if err := sigutil.SignDataWithHandler(
+		key,
+		signatureV2.StableMarshalerWrapper{
+			SM: id.ToV2(),
+		},
+		func(key, sign []byte) {
+			sig.SetKey(key)
+			sig.SetSign(sign)
+		},
+	); err != nil {
+		return nil, err
+	}
+
+	return sig, nil
+}
+
+func CalculateAndSetSignature(key *ecdsa.PrivateKey, obj *RawObject) error {
+	sig, err := CalculateIDSignature(key, obj.ID())
+	if err != nil {
+		return err
+	}
+
+	obj.SetSignature(sig)
+
+	return nil
+}
+
+func VerifyIDSignature(obj *Object) error {
+	return sigutil.VerifyDataWithSource(
+		signatureV2.StableMarshalerWrapper{
+			SM: obj.ID().ToV2(),
+		},
+		func() ([]byte, []byte) {
+			sig := obj.Signature()
+
+			return sig.Key(), sig.Sign()
+		},
+	)
+}
+
+// SetIDWithSignature sets object identifier and signature.
+func SetIDWithSignature(key *ecdsa.PrivateKey, obj *RawObject) error {
+	if err := CalculateAndSetID(obj); err != nil {
+		return fmt.Errorf("could not set identifier: %w", err)
+	}
+
+	if err := CalculateAndSetSignature(key, obj); err != nil {
+		return fmt.Errorf("could not set signature: %w", err)
+	}
+
+	return nil
+}
+
+// SetVerificationFields calculates and sets all verification fields of the object.
+func SetVerificationFields(key *ecdsa.PrivateKey, obj *RawObject) error {
+	CalculateAndSetPayloadChecksum(obj)
+
+	return SetIDWithSignature(key, obj)
+}
+
+// CheckVerificationFields checks all verification fields of the object.
+func CheckVerificationFields(obj *Object) error {
+	if err := CheckHeaderVerificationFields(obj); err != nil {
+		return fmt.Errorf("invalid header structure: %w", err)
+	}
+
+	if err := VerifyPayloadChecksum(obj); err != nil {
+		return fmt.Errorf("invalid payload checksum: %w", err)
+	}
+
+	return nil
+}
+
+// CheckHeaderVerificationFields checks all verification fields except payload.
+func CheckHeaderVerificationFields(obj *Object) error {
+	if err := VerifyIDSignature(obj); err != nil {
+		return fmt.Errorf("invalid signature: %w", err)
+	}
+
+	if err := VerifyID(obj); err != nil {
+		return fmt.Errorf("invalid identifier: %w", err)
+	}
+
+	return nil
+}