[#1255] node/session: Add persistent session storage

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/services/session/storage/persistent/executor.go

@@ -0,0 +1,72 @@
+package persistent
+
+import (
+	"context"
+	"encoding/hex"
+	"fmt"
+
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neofs-api-go/v2/session"
+	"github.com/nspcc-dev/neofs-node/pkg/services/session/storage"
+	"github.com/nspcc-dev/neofs-sdk-go/owner"
+	"go.etcd.io/bbolt"
+)
+
+// Create inits a new private session token using information
+// from corresponding request, saves it to bolt database (and
+// encrypts private keys if storage has been configured so).
+// Returns response that is filled with just created token's
+// ID and public key for it.
+func (s *TokenStore) Create(ctx context.Context, body *session.CreateRequestBody) (*session.CreateResponseBody, error) {
+	ownerBytes, err := owner.NewIDFromV2(body.GetOwnerID()).Marshal()
+	if err != nil {
+		panic(err)
+	}
+
+	uidBytes, err := storage.NewTokenID()
+	if err != nil {
+		return nil, fmt.Errorf("could not generate token ID: %w", err)
+	}
+
+	sk, err := keys.NewPrivateKey()
+	if err != nil {
+		return nil, err
+	}
+
+	value, err := packToken(body.GetExpiration(), &sk.PrivateKey)
+	if err != nil {
+		return nil, err
+	}
+
+	err = s.db.Update(func(tx *bbolt.Tx) error {
+		rootBucket := tx.Bucket(sessionsBucket)
+
+		ownerBucket, err := rootBucket.CreateBucketIfNotExists(ownerBytes)
+		if err != nil {
+			return fmt.Errorf(
+				"could not get/create %s owner bucket: %w",
+				hex.EncodeToString(ownerBytes),
+				err,
+			)
+		}
+
+		err = ownerBucket.Put(uidBytes, value)
+		if err != nil {
+			return fmt.Errorf("could not put session token for %s oid: %w",
+				hex.EncodeToString(ownerBytes),
+				err,
+			)
+		}
+
+		return nil
+	})
+	if err != nil {
+		return nil, fmt.Errorf("could not save token to persistent storage: %w", err)
+	}
+
+	res := new(session.CreateResponseBody)
+	res.SetID(uidBytes)
+	res.SetSessionKey(sk.PublicKey().Bytes())
+
+	return res, nil
+}