interop/native: always use proper ScriptHashGetter, fix #924

All scripts are run in VM, so it's there to tell us about script hashes
involved and it must be used instead of nep5ScriptHash kludge.

pkg/core/interop/context.go

@@ -31,6 +31,7 @@ type Context struct {
 	Notifications []state.NotificationEvent
 	Log           *zap.Logger
 	Invocations   map[util.Uint160]int
+	ScriptGetter  vm.ScriptHashGetter
 }
 
 // NewContext returns new interop context.

pkg/core/interop/runtime/witness.go

@@ -12,9 +12,9 @@ import (
 
 // CheckHashedWitness checks given hash against current list of script hashes
 // for verifying in the interop context.
-func CheckHashedWitness(ic *interop.Context, v vm.ScriptHashGetter, hash util.Uint160) (bool, error) {
+func CheckHashedWitness(ic *interop.Context, hash util.Uint160) (bool, error) {
 	if tx, ok := ic.Container.(*transaction.Transaction); ok {
-		return checkScope(ic.DAO, tx, v, hash)
+		return checkScope(ic.DAO, tx, ic.ScriptGetter, hash)
 	}
 
 	// only for non-Transaction types (Block, etc.)
@@ -77,8 +77,8 @@ func checkScope(d dao.DAO, tx *transaction.Transaction, v vm.ScriptHashGetter, h
 
 // CheckKeyedWitness checks hash of signature check contract with a given public
 // key against current list of script hashes for verifying in the interop context.
-func CheckKeyedWitness(ic *interop.Context, v vm.ScriptHashGetter, key *keys.PublicKey) (bool, error) {
-	return CheckHashedWitness(ic, v, key.GetScriptHash())
+func CheckKeyedWitness(ic *interop.Context, key *keys.PublicKey) (bool, error) {
+	return CheckHashedWitness(ic, key.GetScriptHash())
 }
 
 // CheckWitness checks witnesses.
@@ -94,9 +94,9 @@ func CheckWitness(ic *interop.Context, v *vm.VM) error {
 		if err != nil {
 			return errors.New("parameter given is neither a key nor a hash")
 		}
-		res, err = CheckKeyedWitness(ic, v, key)
+		res, err = CheckKeyedWitness(ic, key)
 	} else {
-		res, err = CheckHashedWitness(ic, v, hash)
+		res, err = CheckHashedWitness(ic, hash)
 	}
 	if err != nil {
 		return errors.Wrap(err, "failed to check")

pkg/core/interops.go

@@ -32,6 +32,7 @@ func SpawnVM(ic *interop.Context) *vm.VM {
 	if ic.Chain != nil {
 		vm.RegisterInteropGetter(ic.Chain.(*Blockchain).contracts.GetNativeInterop(ic))
 	}
+	ic.ScriptGetter = vm
 	return vm
 }
 

pkg/core/native/native_neo.go

@@ -253,11 +253,7 @@ func (n *NEO) vote(ic *interop.Context, args []stackitem.Item) stackitem.Item {
 
 // VoteInternal votes from account h for validarors specified in pubs.
 func (n *NEO) VoteInternal(ic *interop.Context, h util.Uint160, pubs keys.PublicKeys) error {
-	ok, err := runtime.CheckHashedWitness(ic, nep5ScriptHash{
-		callingScriptHash: util.Uint160{},
-		entryScriptHash:   n.Hash,
-		currentScriptHash: n.Hash,
-	}, h)
+	ok, err := runtime.CheckHashedWitness(ic, h)
 	if err != nil {
 		return err
 	} else if !ok {

pkg/core/native/native_nep5.go

@@ -175,11 +175,7 @@ func (c *nep5TokenNative) transfer(ic *interop.Context, from, to util.Uint160, a
 		return errors.New("negative amount")
 	}
 
-	ok, err := runtime.CheckHashedWitness(ic, nep5ScriptHash{
-		callingScriptHash: c.Hash,
-		entryScriptHash:   c.Hash,
-		currentScriptHash: c.Hash,
-	}, from)
+	ok, err := runtime.CheckHashedWitness(ic, from)
 	if err != nil {
 		return err
 	} else if !ok {
@@ -301,29 +297,6 @@ func toUint160(s stackitem.Item) util.Uint160 {
 	return u
 }
 
-// scriptHash is an auxiliary structure which implements ScriptHashGetter
-// interface over NEP5 native contract and is used for runtime.CheckHashedWitness
-type nep5ScriptHash struct {
-	callingScriptHash util.Uint160
-	entryScriptHash   util.Uint160
-	currentScriptHash util.Uint160
-}
-
-// GetCallingScriptHash implements ScriptHashGetter interface
-func (s nep5ScriptHash) GetCallingScriptHash() util.Uint160 {
-	return s.callingScriptHash
-}
-
-// GetEntryScriptHash implements ScriptHashGetter interface
-func (s nep5ScriptHash) GetEntryScriptHash() util.Uint160 {
-	return s.entryScriptHash
-}
-
-// GetCurrentScriptHash implements ScriptHashGetter interface
-func (s nep5ScriptHash) GetCurrentScriptHash() util.Uint160 {
-	return s.currentScriptHash
-}
-
 func getOnPersistWrapper(f func(ic *interop.Context) error) interop.Method {
 	return func(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
 		return stackitem.NewBool(f(ic) == nil)

pkg/core/native/policy.go

@@ -423,11 +423,7 @@ func (p *Policy) checkValidators(ic *interop.Context) (bool, error) {
 	if err != nil {
 		return false, err
 	}
-	return runtime.CheckHashedWitness(ic, nep5ScriptHash{
-		callingScriptHash: p.Hash,
-		entryScriptHash:   p.Hash,
-		currentScriptHash: p.Hash,
-	}, prevBlock.NextConsensus)
+	return runtime.CheckHashedWitness(ic, prevBlock.NextConsensus)
 }
 
 // CheckPolicy checks whether transaction's script hashes for verifying are