[#505] ir/container: Replace key ownership check into a separate method

Method of key ownership verification is going to be reused by the handlers
of the other events.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/innerring/processors/container/common.go

@@ -0,0 +1,27 @@
+package container
+
+import (
+	"fmt"
+
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
+)
+
+type ownerIDSource interface {
+	OwnerID() *owner.ID
+}
+
+func (cp *Processor) checkKeyOwnership(ownerIDSrc ownerIDSource, key *keys.PublicKey) error {
+	ownerKeys, err := cp.idClient.AccountKeys(ownerIDSrc.OwnerID())
+	if err != nil {
+		return fmt.Errorf("could not received owner keys %s: %w", ownerIDSrc.OwnerID(), err)
+	}
+
+	for _, ownerKey := range ownerKeys {
+		if ownerKey.Equal(key) {
+			return nil
+		}
+	}
+
+	return fmt.Errorf("key %s is not tied to the owner of the container", key)
+}

pkg/innerring/processors/container/process_eacl.go

@@ -63,21 +63,8 @@ func (cp *Processor) checkEACLOwnership(binTable []byte, key *keys.PublicKey) er
 		return fmt.Errorf("could not receive the container: %w", err)
 	}
 
-	ownerID := cnr.OwnerID()
-
 	// check key ownership
-	ownerKeys, err := cp.idClient.AccountKeys(ownerID)
-	if err != nil {
-		return fmt.Errorf("could not received owner keys %s: %w", ownerID, err)
-	}
-
-	for _, ownerKey := range ownerKeys {
-		if ownerKey.Equal(key) {
-			return nil
-		}
-	}
-
-	return fmt.Errorf("key %s is not tied to the owner of the container", key)
+	return cp.checkKeyOwnership(cnr, key)
 }
 
 func (cp *Processor) approveSetEACL(e container.SetEACL) {