[#137] Add exp to ResSessionCreate

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

client/session.go

@@ -28,6 +28,8 @@ type ResSessionCreate struct {
 	id []byte
 
 	sessionKey []byte
+
+	exp uint64
 }
 
 func (x *ResSessionCreate) setID(id []byte) {
@@ -50,6 +52,15 @@ func (x ResSessionCreate) PublicKey() []byte {
 	return x.sessionKey
 }
 
+func (x *ResSessionCreate) setExp(exp uint64) {
+	x.exp = exp
+}
+
+// Expiration returns epoch number of the token expiration.
+func (x ResSessionCreate) Expiration() uint64 {
+	return x.exp
+}
+
 // SessionCreate opens a session with the node server on the remote endpoint.
 // The session lifetime coincides with the server lifetime. Results can be written
 // to session token which can be later attached to the requests.
@@ -104,6 +115,7 @@ func (c *Client) SessionCreate(ctx context.Context, prm PrmSessionCreate) (*ResS
 
 		res.setID(body.GetID())
 		res.setSessionKey(body.GetSessionKey())
+		res.setExp(reqBody.GetExpiration())
 	}
 
 	// process call

pool/pool.go

@@ -1671,6 +1671,7 @@ func sessionTokenForOwner(id *owner.ID, cliRes *sdkClient.ResSessionCreate) *ses
 	st.SetOwnerID(id)
 	st.SetID(cliRes.ID())
 	st.SetSessionKey(cliRes.PublicKey())
+	st.SetExp(cliRes.Expiration())
 
 	return st
 }