[#1307] object: Implement Patch method

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

pkg/services/object/patch/util.go

@@ -0,0 +1,53 @@
+package patchsvc
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"errors"
+	"fmt"
+
+	objectV2 "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/refs"
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/session"
+	putsvc "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/put"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/util"
+	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+)
+
+// putInitPrm initializes put paramerer for Put stream.
+func (s *Streamer) putInitPrm(req *objectV2.PatchRequest, obj *objectV2.Object) (*putsvc.PutInitPrm, error) {
+	commonPrm, err := util.CommonPrmFromV2(req)
+	if err != nil {
+		return nil, err
+	}
+
+	prm := new(putsvc.PutInitPrm)
+	prm.WithObject(objectSDK.NewFromV2(obj)).
+		WithCommonPrm(commonPrm).
+		WithPrivateKey(s.localNodeKey)
+
+	return prm, nil
+}
+
+func newOwnerID(vh *session.RequestVerificationHeader) (*refs.OwnerID, error) {
+	for vh.GetOrigin() != nil {
+		vh = vh.GetOrigin()
+	}
+	sig := vh.GetBodySignature()
+	if sig == nil {
+		return nil, errors.New("empty body signature")
+	}
+	key, err := keys.NewPublicKeyFromBytes(sig.GetKey(), elliptic.P256())
+	if err != nil {
+		return nil, fmt.Errorf("invalid signature key: %w", err)
+	}
+
+	var userID user.ID
+	user.IDFromKey(&userID, (ecdsa.PublicKey)(*key))
+	ownID := new(refs.OwnerID)
+	userID.WriteToV2(ownID)
+
+	return ownID, nil
+}