neo-go/pkg/core/interop_neo.go
Anna Shaleva fe1f0a7245 core: introduce CheckReturnState constants
At the moment we should have 3 possible options to check return state
during vm context unloading:
	* no check
	* ensure the stack is empty
	* ensure the stack is not empty

It is necessary to distinguish them because new _deploy method shouldn't
left anything on stack. Example: if we use _deploy method before some
ordinary contract method which returns one value. Without these changes
the contract invocation will fail due to 2 elements on stack left after
invocation (the first `null` element is from _deploy, the second element
is return-value from the ordinary contract method).
2020-10-13 19:14:44 +03:00

257 lines
8.2 KiB
Go

package core
import (
"bytes"
"encoding/base64"
"errors"
"fmt"
"sort"
"github.com/mr-tron/base58"
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"github.com/nspcc-dev/neo-go/pkg/core/interop/contract"
"github.com/nspcc-dev/neo-go/pkg/core/state"
"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
"github.com/nspcc-dev/neo-go/pkg/smartcontract"
"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
"github.com/nspcc-dev/neo-go/pkg/vm"
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
const (
// MaxContractDescriptionLen is the maximum length for contract description.
MaxContractDescriptionLen = 65536
// MaxContractScriptSize is the maximum script size for a contract.
MaxContractScriptSize = 1024 * 1024
// MaxContractParametersNum is the maximum number of parameters for a contract.
MaxContractParametersNum = 252
// MaxContractStringLen is the maximum length for contract metadata strings.
MaxContractStringLen = 252
)
var errGasLimitExceeded = errors.New("gas limit exceeded")
// storageFind finds stored key-value pair.
func storageFind(ic *interop.Context) error {
stcInterface := ic.VM.Estack().Pop().Value()
stc, ok := stcInterface.(*StorageContext)
if !ok {
return fmt.Errorf("%T is not a StorageContext", stcInterface)
}
prefix := ic.VM.Estack().Pop().Bytes()
siMap, err := ic.DAO.GetStorageItemsWithPrefix(stc.ID, prefix)
if err != nil {
return err
}
filteredMap := stackitem.NewMap()
for k, v := range siMap {
filteredMap.Add(stackitem.NewByteArray(append(prefix, []byte(k)...)), stackitem.NewByteArray(v.Value))
}
sort.Slice(filteredMap.Value().([]stackitem.MapElement), func(i, j int) bool {
return bytes.Compare(filteredMap.Value().([]stackitem.MapElement)[i].Key.Value().([]byte),
filteredMap.Value().([]stackitem.MapElement)[j].Key.Value().([]byte)) == -1
})
item := vm.NewMapIterator(filteredMap)
ic.VM.Estack().PushVal(item)
return nil
}
// createContractStateFromVM pops all contract state elements from the VM
// evaluation stack, does a lot of checks and returns Contract if it
// succeeds.
func createContractStateFromVM(ic *interop.Context) (*state.Contract, error) {
script := ic.VM.Estack().Pop().Bytes()
if len(script) > MaxContractScriptSize {
return nil, errors.New("the script is too big")
}
manifestBytes := ic.VM.Estack().Pop().Bytes()
if len(manifestBytes) > manifest.MaxManifestSize {
return nil, errors.New("manifest is too big")
}
if !ic.VM.AddGas(int64(StoragePrice * (len(script) + len(manifestBytes)))) {
return nil, errGasLimitExceeded
}
var m manifest.Manifest
err := m.UnmarshalJSON(manifestBytes)
if err != nil {
return nil, fmt.Errorf("unable to retrieve manifest from stack: %w", err)
}
return &state.Contract{
Script: script,
Manifest: m,
}, nil
}
// contractCreate creates a contract.
func contractCreate(ic *interop.Context) error {
newcontract, err := createContractStateFromVM(ic)
if err != nil {
return err
}
contract, err := ic.DAO.GetContractState(newcontract.ScriptHash())
if contract != nil && err == nil {
return errors.New("contract already exists")
}
id, err := ic.DAO.GetAndUpdateNextContractID()
if err != nil {
return err
}
newcontract.ID = id
if !newcontract.Manifest.IsValid(newcontract.ScriptHash()) {
return errors.New("failed to check contract script hash against manifest")
}
if err := ic.DAO.PutContractState(newcontract); err != nil {
return err
}
cs, err := contractToStackItem(newcontract)
if err != nil {
return fmt.Errorf("cannot convert contract to stack item: %w", err)
}
ic.VM.Estack().PushVal(cs)
return callDeploy(ic, newcontract, false)
}
func checkNonEmpty(b []byte, max int) error {
if b != nil {
if l := len(b); l == 0 {
return errors.New("empty")
} else if l > max {
return fmt.Errorf("len is %d (max %d)", l, max)
}
}
return nil
}
// contractUpdate migrates a contract. This method assumes that Manifest and Script
// of the contract can be updated independently.
func contractUpdate(ic *interop.Context) error {
contract, _ := ic.DAO.GetContractState(ic.VM.GetCurrentScriptHash())
if contract == nil {
return errors.New("contract doesn't exist")
}
script := ic.VM.Estack().Pop().BytesOrNil()
manifestBytes := ic.VM.Estack().Pop().BytesOrNil()
if script == nil && manifestBytes == nil {
return errors.New("both script and manifest are nil")
}
if err := checkNonEmpty(script, MaxContractScriptSize); err != nil {
return fmt.Errorf("invalid script size: %w", err)
}
if err := checkNonEmpty(manifestBytes, manifest.MaxManifestSize); err != nil {
return fmt.Errorf("invalid manifest size: %w", err)
}
if !ic.VM.AddGas(int64(StoragePrice * (len(script) + len(manifestBytes)))) {
return errGasLimitExceeded
}
// if script was provided, update the old contract script and Manifest.ABI hash
if script != nil {
newHash := hash.Hash160(script)
if newHash.Equals(contract.ScriptHash()) {
return errors.New("the script is the same")
} else if _, err := ic.DAO.GetContractState(newHash); err == nil {
return errors.New("contract already exists")
}
oldHash := contract.ScriptHash()
// re-write existing contract variable, as we need it to be up-to-date during manifest update
contract = &state.Contract{
ID: contract.ID,
Script: script,
Manifest: contract.Manifest,
}
contract.Manifest.ABI.Hash = newHash
if err := ic.DAO.PutContractState(contract); err != nil {
return fmt.Errorf("failed to update script: %w", err)
}
if err := ic.DAO.DeleteContractState(oldHash); err != nil {
return fmt.Errorf("failed to update script: %w", err)
}
}
// if manifest was provided, update the old contract manifest and check associated
// storage items if needed
if manifestBytes != nil {
var newManifest manifest.Manifest
err := newManifest.UnmarshalJSON(manifestBytes)
if err != nil {
return fmt.Errorf("unable to retrieve manifest from stack: %w", err)
}
// we don't have to perform `GetContractState` one more time as it's already up-to-date
contract.Manifest = newManifest
if !contract.Manifest.IsValid(contract.ScriptHash()) {
return errors.New("failed to check contract script hash against new manifest")
}
if !contract.HasStorage() {
siMap, err := ic.DAO.GetStorageItems(contract.ID)
if err != nil {
return fmt.Errorf("failed to update manifest: %w", err)
}
if len(siMap) != 0 {
return errors.New("old contract shouldn't have storage")
}
}
if err := ic.DAO.PutContractState(contract); err != nil {
return fmt.Errorf("failed to update manifest: %w", err)
}
}
return callDeploy(ic, contract, true)
}
func callDeploy(ic *interop.Context, cs *state.Contract, isUpdate bool) error {
md := cs.Manifest.ABI.GetMethod(manifest.MethodDeploy)
if md != nil {
return contract.CallExInternal(ic, cs, manifest.MethodDeploy,
[]stackitem.Item{stackitem.NewBool(isUpdate)}, smartcontract.All, vm.EnsureIsEmpty)
}
return nil
}
// runtimeSerialize serializes top stack item into a ByteArray.
func runtimeSerialize(ic *interop.Context) error {
return vm.RuntimeSerialize(ic.VM)
}
// runtimeDeserialize deserializes ByteArray from a stack into an item.
func runtimeDeserialize(ic *interop.Context) error {
return vm.RuntimeDeserialize(ic.VM)
}
// runtimeEncodeBase64 encodes top stack item into a base64 string.
func runtimeEncodeBase64(ic *interop.Context) error {
src := ic.VM.Estack().Pop().Bytes()
result := base64.StdEncoding.EncodeToString(src)
ic.VM.Estack().PushVal([]byte(result))
return nil
}
// runtimeDecodeBase64 decodes top stack item from base64 string to byte array.
func runtimeDecodeBase64(ic *interop.Context) error {
src := ic.VM.Estack().Pop().String()
result, err := base64.StdEncoding.DecodeString(src)
if err != nil {
return err
}
ic.VM.Estack().PushVal(result)
return nil
}
// runtimeEncodeBase58 encodes top stack item into a base58 string.
func runtimeEncodeBase58(ic *interop.Context) error {
src := ic.VM.Estack().Pop().Bytes()
result := base58.Encode(src)
ic.VM.Estack().PushVal([]byte(result))
return nil
}
// runtimeDecodeBase58 decodes top stack item from base58 string to byte array.
func runtimeDecodeBase58(ic *interop.Context) error {
src := ic.VM.Estack().Pop().String()
result, err := base58.Decode(src)
if err != nil {
return err
}
ic.VM.Estack().PushVal(result)
return nil
}