From 74a143cee3e6149e2b08bf52d4a3ce936f77a4b8 Mon Sep 17 00:00:00 2001
From: Anna Shaleva <shaleva.ann@nspcc.ru>
Date: Mon, 7 Dec 2020 11:43:32 +0300
Subject: [PATCH] core: allow to change deposit's `till` for owner only

---
 pkg/core/native/notary.go      | 20 +++++++++++++-------
 pkg/core/native_notary_test.go | 25 ++++++++++++++++++++++++-
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/pkg/core/native/notary.go b/pkg/core/native/notary.go
index f20010bca2..0d692670ca 100644
--- a/pkg/core/native/notary.go
+++ b/pkg/core/native/notary.go
@@ -33,7 +33,8 @@ const (
 	notaryContractID = reservedContractID - 1
 
 	// prefixDeposit is a prefix for storing Notary deposits.
-	prefixDeposit = 1
+	prefixDeposit           = 1
+	defaultDepositDeltaTill = 5760
 )
 
 // newNotary returns Notary native contract.
@@ -158,13 +159,17 @@ func (n *Notary) onPayment(ic *interop.Context, args []stackitem.Item) stackitem
 	if !additionalParams[0].Equals(stackitem.Null{}) {
 		to = toUint160(additionalParams[0])
 	}
-	till := toUint32(additionalParams[1])
+
+	allowedChangeTill := ic.Tx.Sender() == to
 	currentHeight := ic.Chain.BlockHeight()
+	deposit := n.getDepositFor(ic.DAO, to)
+	till := toUint32(additionalParams[1])
 	if till < currentHeight {
 		panic(fmt.Errorf("`till` shouldn't be less then the chain's height %d", currentHeight))
 	}
-
-	deposit := n.getDepositFor(ic.DAO, to)
+	if deposit != nil && till < deposit.Till {
+		panic(fmt.Errorf("`till` shouldn't be less then the previous value %d", deposit.Till))
+	}
 	if deposit == nil {
 		if amount.Cmp(big.NewInt(2*transaction.NotaryServiceFeePerKey)) < 0 {
 			panic(fmt.Errorf("first deposit can not be less then %d, got %d", 2*transaction.NotaryServiceFeePerKey, amount.Int64()))
@@ -172,10 +177,11 @@ func (n *Notary) onPayment(ic *interop.Context, args []stackitem.Item) stackitem
 		deposit = &state.Deposit{
 			Amount: new(big.Int),
 		}
-	} else {
-		if till < deposit.Till {
-			panic(fmt.Errorf("`till` shouldn't be less then the previous value %d", deposit.Till))
+		if !allowedChangeTill {
+			till = currentHeight + defaultDepositDeltaTill
 		}
+	} else if !allowedChangeTill { // only deposit's owner is allowed to set or update `till`
+		till = deposit.Till
 	}
 	deposit.Amount.Add(deposit.Amount, amount)
 	deposit.Till = till
diff --git a/pkg/core/native_notary_test.go b/pkg/core/native_notary_test.go
index 33d9703a63..2a67bc4235 100644
--- a/pkg/core/native_notary_test.go
+++ b/pkg/core/native_notary_test.go
@@ -1,6 +1,7 @@
 package core
 
 import (
+	"math"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/testchain"
@@ -24,7 +25,7 @@ func TestNotaryContractPipeline(t *testing.T) {
 
 	notaryHash := chain.contracts.Notary.Hash
 	gasHash := chain.contracts.GAS.Hash
-	depositLock := 30
+	depositLock := 100
 
 	// check Notary contract has no GAS on the account
 	checkBalanceOf(t, chain, notaryHash, 0)
@@ -217,6 +218,28 @@ func TestNotaryContractPipeline(t *testing.T) {
 	withdrawRes, err = invokeContractMethod(chain, 100000000, notaryHash, "withdraw", testchain.MultisigScriptHash(), testchain.MultisigScriptHash())
 	require.NoError(t, err)
 	checkResult(t, withdrawRes, stackitem.NewBool(false))
+
+	// `onPayment`: good first deposit to other account, should set default `till` even if other `till` value is provided
+	transferTx = transferTokenFromMultisigAccount(t, chain, notaryHash, gasHash, 2*transaction.NotaryServiceFeePerKey, acc.PrivateKey().PublicKey().GetScriptHash(), int64(math.MaxUint32-1))
+	res, err = chain.GetAppExecResults(transferTx.Hash(), trigger.Application)
+	require.NoError(t, err)
+	require.Equal(t, vm.HaltState, res[0].VMState)
+	require.Equal(t, 0, len(res[0].Stack))
+	checkBalanceOf(t, chain, notaryHash, 2*transaction.NotaryServiceFeePerKey)
+	till, err = invokeContractMethod(chain, 100000000, notaryHash, "expirationOf", acc.PrivateKey().PublicKey().GetScriptHash())
+	require.NoError(t, err)
+	checkResult(t, till, stackitem.Make(5760+chain.BlockHeight()-2))
+
+	// `onPayment`: good second deposit to other account, shouldn't update `till` even if other `till` value is provided
+	transferTx = transferTokenFromMultisigAccount(t, chain, notaryHash, gasHash, 2*transaction.NotaryServiceFeePerKey, acc.PrivateKey().PublicKey().GetScriptHash(), int64(math.MaxUint32-1))
+	res, err = chain.GetAppExecResults(transferTx.Hash(), trigger.Application)
+	require.NoError(t, err)
+	require.Equal(t, vm.HaltState, res[0].VMState)
+	require.Equal(t, 0, len(res[0].Stack))
+	checkBalanceOf(t, chain, notaryHash, 4*transaction.NotaryServiceFeePerKey)
+	till, err = invokeContractMethod(chain, 100000000, notaryHash, "expirationOf", acc.PrivateKey().PublicKey().GetScriptHash())
+	require.NoError(t, err)
+	checkResult(t, till, stackitem.Make(5760+chain.BlockHeight()-4))
 }
 
 func TestNotaryNodesReward(t *testing.T) {