Merge pull request #3256 from fyfyrchik/fix-signer

Allow complex contract signature schemes in `wallet.Account`

pkg/neotest/basic.go

@@ -301,8 +301,9 @@ func AddNetworkFee(t testing.TB, bc *core.Blockchain, tx *transaction.Transactio
 	baseFee := bc.GetBaseExecFee()
 	size := io.GetVarSize(tx)
 	for _, sgr := range signers {
-		if csgr, ok := sgr.(ContractSigner); ok {
-			sc, err := csgr.InvocationScript(tx)
+		csgr, ok := sgr.(SingleSigner)
+		if ok && csgr.Account().Contract.InvocationBuilder != nil {
+			sc, err := csgr.Account().Contract.InvocationBuilder(tx)
 			require.NoError(t, err)
 
 			txCopy := *tx

pkg/neotest/signer.go

@@ -2,7 +2,6 @@ package neotest
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
 	"sort"
 	"testing"
@@ -11,6 +10,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
@@ -47,13 +47,6 @@ type MultiSigner interface {
 	Single(n int) SingleSigner
 }
 
-// ContractSigner is an interface for contract signer.
-type ContractSigner interface {
-	Signer
-	// InvocationScript returns an invocation script to be used as invocation script for contract-based witness.
-	InvocationScript(tx *transaction.Transaction) ([]byte, error)
-}
-
 // signer represents a simple-signature signer.
 type signer wallet.Account
 
@@ -190,23 +183,17 @@ func checkMultiSigner(t testing.TB, s Signer) {
 	}
 }
 
-type contractSigner struct {
-	params     func(tx *transaction.Transaction) []any
-	scriptHash util.Uint160
-}
+type contractSigner wallet.Account
 
 // NewContractSigner returns a contract signer for the provided contract hash.
 // getInvParams must return params to be used as invocation script for contract-based witness.
-func NewContractSigner(h util.Uint160, getInvParams func(tx *transaction.Transaction) []any) ContractSigner {
+func NewContractSigner(h util.Uint160, getInvParams func(tx *transaction.Transaction) []any) SingleSigner {
 	return &contractSigner{
-		scriptHash: h,
-		params:     getInvParams,
-	}
-}
-
-// InvocationScript implements ContractSigner.
-func (s *contractSigner) InvocationScript(tx *transaction.Transaction) ([]byte, error) {
-	params := s.params(tx)
+		Address: address.Uint160ToString(h),
+		Contract: &wallet.Contract{
+			Deployed: true,
+			InvocationBuilder: func(tx *transaction.Transaction) ([]byte, error) {
+				params := getInvParams(tx)
 				script := io.NewBufBinWriter()
 				for i := range params {
 					emit.Any(script.BinWriter, params[i])
@@ -215,6 +202,9 @@ func (s *contractSigner) InvocationScript(tx *transaction.Transaction) ([]byte,
 					return nil, script.Err
 				}
 				return script.Bytes(), nil
+			},
+		},
+	}
 }
 
 // Script implements ContractSigner.
@@ -224,7 +214,12 @@ func (s *contractSigner) Script() []byte {
 
 // ScriptHash implements ContractSigner.
 func (s *contractSigner) ScriptHash() util.Uint160 {
-	return s.scriptHash
+	return s.Account().ScriptHash()
+}
+
+// ScriptHash implements ContractSigner.
+func (s *contractSigner) Account() *wallet.Account {
+	return (*wallet.Account)(s)
 }
 
 // SignHashable implements ContractSigner.
@@ -234,27 +229,7 @@ func (s *contractSigner) SignHashable(uint32, hash.Hashable) []byte {
 
 // SignTx implements ContractSigner.
 func (s *contractSigner) SignTx(magic netmode.Magic, tx *transaction.Transaction) error {
-	pos := -1
-	for idx := range tx.Signers {
-		if tx.Signers[idx].Account.Equals(s.ScriptHash()) {
-			pos = idx
-			break
-		}
-	}
-	if pos < 0 {
-		return fmt.Errorf("signer %s not found", s.ScriptHash().String())
-	}
-	if len(tx.Scripts) < pos {
-		return errors.New("transaction is not yet signed by the previous signer")
-	}
-	invoc, err := s.InvocationScript(tx)
-	if err != nil {
-		return err
-	}
-	if len(tx.Scripts) == pos {
-		tx.Scripts = append(tx.Scripts, transaction.Witness{})
-	}
-	tx.Scripts[pos].InvocationScript = invoc
-	tx.Scripts[pos].VerificationScript = s.Script()
-	return nil
+	// Here we rely on `len(s.Contract.Parameters) == 0` being after the `s.Contract.InvocationBuilder != nil` check,
+	// because we cannot determine the list of parameters unless we already have tx.
+	return s.Account().SignTx(magic, tx)
 }

pkg/rpcclient/actor/maker.go

@@ -191,6 +191,14 @@ func (a *Actor) MakeUnsignedUncheckedRun(script []byte, sysFee int64, attrs []tr
 	for i := range a.signers {
 		if !a.signers[i].Account.Contract.Deployed {
 			tx.Scripts[i].VerificationScript = a.signers[i].Account.Contract.Script
+			continue
+		}
+		if build := a.signers[i].Account.Contract.InvocationBuilder; build != nil {
+			invoc, err := build(tx)
+			if err != nil {
+				return nil, fmt.Errorf("building witness for contract signer: %w", err)
+			}
+			tx.Scripts[i].InvocationScript = invoc
 		}
 	}
 	// CalculateNetworkFee doesn't call Hash or Size, only serializes the

pkg/wallet/account.go

@@ -9,8 +9,10 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
+	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/vm/emit"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 )
 
@@ -55,6 +57,12 @@ type Contract struct {
 
 	// Indicates whether the contract has been deployed to the blockchain.
 	Deployed bool `json:"deployed"`
+
+	// InvocationBuilder returns invocation script for deployed contracts.
+	// In case contract is not deployed or has 0 arguments, this field is ignored.
+	// It might be executed on a partially formed tx, and is primarily needed to properly
+	// calculate network fee for complex contract signers.
+	InvocationBuilder func(tx *transaction.Transaction) ([]byte, error) `json:"-"`
 }
 
 // ContractParam is a descriptor of a contract parameter
@@ -78,6 +86,29 @@ func NewAccount() (*Account, error) {
 	return NewAccountFromPrivateKey(priv), nil
 }
 
+// NewContractAccount creates a contract account belonging to some deployed contract.
+// SignTx can be called on this account with no error and will create invocation script,
+// which puts provided arguments on stack for use in `verify`.
+func NewContractAccount(hash util.Uint160, args ...any) *Account {
+	return &Account{
+		Address: address.Uint160ToString(hash),
+		Contract: &Contract{
+			Parameters: make([]ContractParam, len(args)),
+			Deployed:   true,
+			InvocationBuilder: func(tx *transaction.Transaction) ([]byte, error) {
+				w := io.NewBufBinWriter()
+				for i := range args {
+					emit.Any(w.BinWriter, args[i])
+				}
+				if w.Err != nil {
+					return nil, w.Err
+				}
+				return w.Bytes(), nil
+			},
+		},
+	}
+}
+
 // SignTx signs transaction t and updates it's Witnesses.
 func (a *Account) SignTx(net netmode.Magic, t *transaction.Transaction) error {
 	var (
@@ -108,6 +139,11 @@ func (a *Account) SignTx(net netmode.Magic, t *transaction.Transaction) error {
 			VerificationScript: a.Contract.Script, // Can be nil for deployed contract.
 		})
 	}
+	if a.Contract.Deployed && a.Contract.InvocationBuilder != nil {
+		invoc, err := a.Contract.InvocationBuilder(t)
+		t.Scripts[pos].InvocationScript = invoc
+		return err
+	}
 	if len(a.Contract.Parameters) == 0 {
 		return nil
 	}