core: drop GetScriptHashesForVerifying

It no longer depends on blockchain state and there can't ever be an error, in
fact we can always iterate over signers, so copying these hashes doesn't make
much sense at all as well as sorting arrays in verifyTxWitnesses (witnesses
order must match signers order).

pkg/core/blockchain.go

@@ -1206,20 +1206,16 @@ func (bc *Blockchain) verifyTx(t *transaction.Transaction, block *block.Block) e
 	if t.ValidUntilBlock <= height || t.ValidUntilBlock > height+transaction.MaxValidUntilBlockIncrement {
 		return fmt.Errorf("transaction has expired. ValidUntilBlock = %d, current height = %d", t.ValidUntilBlock, height)
 	}
-	hashes, err := bc.GetScriptHashesForVerifying(t)
-	if err != nil {
-		return err
-	}
 	blockedAccounts, err := bc.contracts.Policy.GetBlockedAccountsInternal(bc.dao)
 	if err != nil {
 		return err
 	}
-	for _, h := range hashes {
+	for _, signer := range t.Signers {
 		i := sort.Search(len(blockedAccounts), func(i int) bool {
-			return !blockedAccounts[i].Less(h)
+			return !blockedAccounts[i].Less(signer.Account)
 		})
-		if i != len(blockedAccounts) && blockedAccounts[i].Equals(h) {
-			return fmt.Errorf("policy check failed: account %s is blocked", h.StringLE())
+		if i != len(blockedAccounts) && blockedAccounts[i].Equals(signer.Account) {
+			return fmt.Errorf("policy check failed: account %s is blocked", signer.Account.StringLE())
 		}
 	}
 	maxBlockSystemFee := bc.contracts.Policy.GetMaxBlockSystemFeeInternal(bc.dao)
@@ -1410,19 +1406,6 @@ func (bc *Blockchain) GetEnrollments() ([]state.Validator, error) {
 	return bc.contracts.NEO.GetRegisteredValidators(bc.dao)
 }
 
-// GetScriptHashesForVerifying returns all the ScriptHashes of a transaction which will be use
-// to verify whether the transaction is bonafide or not.
-// Golang implementation of GetScriptHashesForVerifying method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L190)
-func (bc *Blockchain) GetScriptHashesForVerifying(t *transaction.Transaction) ([]util.Uint160, error) {
-	hashesResult := make([]util.Uint160, len(t.Signers))
-	for i, s := range t.Signers {
-		hashesResult[i] = s.Account
-	}
-
-	return hashesResult, nil
-
-}
-
 // GetTestVM returns a VM and a Store setup for a test run of some sort of code.
 func (bc *Blockchain) GetTestVM(tx *transaction.Transaction) *vm.VM {
 	systemInterop := bc.newInteropContext(trigger.Application, bc.dao, nil, tx)
@@ -1503,20 +1486,12 @@ func (bc *Blockchain) verifyHashAgainstScript(hash util.Uint160, witness *transa
 // not yet added into any block.
 // Golang implementation of VerifyWitnesses method in C# (https://github.com/neo-project/neo/blob/master/neo/SmartContract/Helper.cs#L87).
 func (bc *Blockchain) verifyTxWitnesses(t *transaction.Transaction, block *block.Block) error {
-	hashes, err := bc.GetScriptHashesForVerifying(t)
-	if err != nil {
-		return err
+	if len(t.Signers) != len(t.Scripts) {
+		return fmt.Errorf("number of signers doesn't match witnesses (%d vs %d)", len(t.Signers), len(t.Scripts))
 	}
-
-	witnesses := t.Scripts
-	if len(hashes) != len(witnesses) {
-		return fmt.Errorf("expected len(hashes) == len(witnesses). got: %d != %d", len(hashes), len(witnesses))
-	}
-	sort.Slice(hashes, func(i, j int) bool { return hashes[i].Less(hashes[j]) })
-	sort.Slice(witnesses, func(i, j int) bool { return witnesses[i].ScriptHash().Less(witnesses[j].ScriptHash()) })
 	interopCtx := bc.newInteropContext(trigger.Verification, bc.dao, block, t)
-	for i := 0; i < len(hashes); i++ {
-		err := bc.verifyHashAgainstScript(hashes[i], &witnesses[i], interopCtx, false, t.NetworkFee)
+	for i := range t.Signers {
+		err := bc.verifyHashAgainstScript(t.Signers[i].Account, &t.Scripts[i], interopCtx, false, t.NetworkFee)
 		if err != nil {
 			return fmt.Errorf("witness #%d: %w", i, err)
 		}

pkg/core/blockchainer/blockchainer.go

@@ -43,7 +43,6 @@ type Blockchainer interface {
 	GetNEP5Balances(util.Uint160) *state.NEP5Balances
 	GetValidators() ([]*keys.PublicKey, error)
 	GetStandByValidators() keys.PublicKeys
-	GetScriptHashesForVerifying(*transaction.Transaction) ([]util.Uint160, error)
 	GetStateRoot(height uint32) (*state.MPTRootState, error)
 	GetStorageItem(id int32, key []byte) *state.StorageItem
 	GetStorageItems(id int32) (map[string]*state.StorageItem, error)

pkg/core/native/policy.go

@@ -516,14 +516,10 @@ func (p *Policy) CheckPolicy(ic *interop.Context, tx *transaction.Transaction) e
 	if err != nil {
 		return fmt.Errorf("unable to get blocked accounts list: %w", err)
 	}
-	scriptHashes, err := ic.Chain.GetScriptHashesForVerifying(tx)
-	if err != nil {
-		return fmt.Errorf("unable to get tx script hashes: %w", err)
-	}
 	for _, acc := range ba {
-		for _, hash := range scriptHashes {
-			if acc.Equals(hash) {
-				return fmt.Errorf("account %s is blocked", hash.StringLE())
+		for _, signer := range tx.Signers {
+			if acc.Equals(signer.Account) {
+				return fmt.Errorf("account %s is blocked", acc.StringLE())
 			}
 		}
 	}

pkg/network/helper_test.go

@@ -109,9 +109,6 @@ func (chain testChain) GetStandByValidators() keys.PublicKeys {
 func (chain testChain) GetEnrollments() ([]state.Validator, error) {
 	panic("TODO")
 }
-func (chain testChain) GetScriptHashesForVerifying(*transaction.Transaction) ([]util.Uint160, error) {
-	panic("TODO")
-}
 func (chain testChain) GetStateRoot(height uint32) (*state.MPTRootState, error) {
 	panic("TODO")
 }