core: adjust System.Runtime.GetRandom

1. Make seed dependant on the GetRandom invocations counter.
2. Adjust syscall price.

pkg/core/interop/context.go

@@ -45,26 +45,27 @@ type Ledger interface {
 
 // Context represents context in which interops are executed.
 type Context struct {
-	Chain          Ledger
+	Chain            Ledger
-	Container      hash.Hashable
+	Container        hash.Hashable
-	Network        uint32
+	Network          uint32
-	Hardforks      map[string]uint32
+	Hardforks        map[string]uint32
-	Natives        []Contract
+	Natives          []Contract
-	Trigger        trigger.Type
+	Trigger          trigger.Type
-	Block          *block.Block
+	Block            *block.Block
-	NonceData      [16]byte
+	NonceData        [16]byte
-	Tx             *transaction.Transaction
+	Tx               *transaction.Transaction
-	DAO            *dao.Simple
+	DAO              *dao.Simple
-	Notifications  []state.NotificationEvent
+	Notifications    []state.NotificationEvent
-	Log            *zap.Logger
+	Log              *zap.Logger
-	VM             *vm.VM
+	VM               *vm.VM
-	Functions      []Function
+	Functions        []Function
-	Invocations    map[util.Uint160]int
+	Invocations      map[util.Uint160]int
-	cancelFuncs    []context.CancelFunc
+	cancelFuncs      []context.CancelFunc
-	getContract    func(*dao.Simple, util.Uint160) (*state.Contract, error)
+	getContract      func(*dao.Simple, util.Uint160) (*state.Contract, error)
-	baseExecFee    int64
+	baseExecFee      int64
-	baseStorageFee int64
+	baseStorageFee   int64
-	signers        []transaction.Signer
+	GetRandomCounter uint32
+	signers          []transaction.Signer
 }
 
 // NewContext returns new interop context.

pkg/core/interop/runtime/util.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"math/big"
 
+	"github.com/nspcc-dev/neo-go/pkg/config"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
@@ -88,9 +89,26 @@ func GetNetwork(ic *interop.Context) error {
 
 // GetRandom returns pseudo-random number which depends on block nonce and transaction hash.
 func GetRandom(ic *interop.Context) error {
-	res := murmur128(ic.NonceData[:], ic.Network)
+	var (
+		price int64
+		seed  = ic.Network
+	)
+	isHF := ic.IsHardforkEnabled(config.HF2712FixSyscallFees)
+	if isHF {
+		price = 1 << 13
+		seed += ic.GetRandomCounter
+		ic.GetRandomCounter++
+	} else {
+		price = 1 << 4
+	}
+	res := murmur128(ic.NonceData[:], seed)
+	if !isHF {
+		copy(ic.NonceData[:], res)
+	}
+	if !ic.VM.AddGas(ic.BaseExecFee() * price) {
+		return errors.New("gas limit exceeded")
+	}
 	ic.VM.Estack().PushItem(stackitem.NewBigInteger(bigint.FromBytesUnsigned(res)))
-	copy(ic.NonceData[:], res)
 	return nil
 }
 

pkg/core/interop_system_core_test.go

@@ -46,25 +46,26 @@ func TestRuntimeGetRandomCompatibility(t *testing.T) {
 	b := getSharpTestGenesis(t)
 	tx := getSharpTestTx(util.Uint160{})
 	ic := bc.newInteropContext(trigger.Application, bc.dao.GetWrapped(), b, tx)
-	ic.Network = 5195086 // Old mainnet magic used by C# tests.
+	ic.Network = 860833102 // Old mainnet magic used by C# tests.
 
 	ic.VM = vm.New()
 	ic.VM.LoadScript([]byte{0x01})
+	ic.VM.GasLimit = 1100_00000000
 
 	require.NoError(t, runtime.GetRandom(ic))
-	require.Equal(t, "225932872514876835587448704843370203748", ic.VM.Estack().Pop().BigInt().String())
+	require.Equal(t, "271339657438512451304577787170704246350", ic.VM.Estack().Pop().BigInt().String())
 
 	require.NoError(t, runtime.GetRandom(ic))
-	require.Equal(t, "190129535548110356450238097068474508661", ic.VM.Estack().Pop().BigInt().String())
+	require.Equal(t, "98548189559099075644778613728143131367", ic.VM.Estack().Pop().BigInt().String())
 
 	require.NoError(t, runtime.GetRandom(ic))
-	require.Equal(t, "48930406787011198493485648810190184269", ic.VM.Estack().Pop().BigInt().String())
+	require.Equal(t, "247654688993873392544380234598471205121", ic.VM.Estack().Pop().BigInt().String())
 
 	require.NoError(t, runtime.GetRandom(ic))
-	require.Equal(t, "66199389469641263539889463157823839112", ic.VM.Estack().Pop().BigInt().String())
+	require.Equal(t, "291082758879475329976578097236212073607", ic.VM.Estack().Pop().BigInt().String())
 
 	require.NoError(t, runtime.GetRandom(ic))
-	require.Equal(t, "217172703763162599519098299724476526911", ic.VM.Estack().Pop().BigInt().String())
+	require.Equal(t, "247152297361212656635216876565962360375", ic.VM.Estack().Pop().BigInt().String())
 }
 
 func getSharpTestTx(sender util.Uint160) *transaction.Transaction {
@@ -74,7 +75,8 @@ func getSharpTestTx(sender util.Uint160) *transaction.Transaction {
 		Account: sender,
 		Scopes:  transaction.CalledByEntry,
 	})
-	tx.Scripts = append(tx.Scripts, transaction.Witness{})
+	tx.Attributes = []transaction.Attribute{}
+	tx.Scripts = append(tx.Scripts, transaction.Witness{InvocationScript: []byte{}, VerificationScript: []byte{}})
 	return tx
 }
 

pkg/core/interops.go

@@ -53,7 +53,7 @@ var systemInterops = []interop.Function{
 	{Name: interopnames.SystemRuntimeGetInvocationCounter, Func: runtime.GetInvocationCounter, Price: 1 << 4},
 	{Name: interopnames.SystemRuntimeGetNetwork, Func: runtime.GetNetwork, Price: 1 << 3},
 	{Name: interopnames.SystemRuntimeGetNotifications, Func: runtime.GetNotifications, Price: 1 << 12, ParamCount: 1},
-	{Name: interopnames.SystemRuntimeGetRandom, Func: runtime.GetRandom, Price: 1 << 4},
+	{Name: interopnames.SystemRuntimeGetRandom, Func: runtime.GetRandom, Price: 0},
 	{Name: interopnames.SystemRuntimeGetScriptContainer, Func: engineGetScriptContainer, Price: 1 << 3},
 	{Name: interopnames.SystemRuntimeGetTime, Func: runtime.GetTime, Price: 1 << 3, RequiredFlags: callflag.ReadStates},
 	{Name: interopnames.SystemRuntimeGetTrigger, Func: runtime.GetTrigger, Price: 1 << 3},