package core import ( "crypto/elliptic" "errors" "fmt" "math" "github.com/nspcc-dev/neo-go/pkg/core/block" "github.com/nspcc-dev/neo-go/pkg/core/interop" "github.com/nspcc-dev/neo-go/pkg/core/native" "github.com/nspcc-dev/neo-go/pkg/core/state" "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/smartcontract" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm" "github.com/nspcc-dev/neo-go/pkg/vm/stackitem" ) const ( // MaxStorageKeyLen is the maximum length of a key for storage items. MaxStorageKeyLen = 64 // MaxStorageValueLen is the maximum length of a value for storage items. // It is set to be the maximum value for uint16. MaxStorageValueLen = 65535 ) // StorageContext contains storing id and read/write flag, it's used as // a context for storage manipulation functions. type StorageContext struct { ID int32 ReadOnly bool } // StorageFlag represents storage flag which denotes whether the stored value is // a constant. type StorageFlag byte const ( // None is a storage flag for non-constant items. None StorageFlag = 0 // Constant is a storage flag for constant items. Constant StorageFlag = 0x01 ) // engineGetScriptContainer returns transaction or block that contains the script // being run. func engineGetScriptContainer(ic *interop.Context) error { var item stackitem.Item switch t := ic.Container.(type) { case *transaction.Transaction: item = native.TransactionToStackItem(t) case *block.Block: item = native.BlockToStackItem(t) default: return errors.New("unknown script container") } ic.VM.Estack().PushVal(item) return nil } // storageDelete deletes stored key-value pair. func storageDelete(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) } if stc.ReadOnly { return errors.New("StorageContext is read only") } ic.VM.AddGas(ic.Chain.GetPolicer().GetStoragePrice()) key := ic.VM.Estack().Pop().Bytes() si := ic.DAO.GetStorageItem(stc.ID, key) if si != nil && si.IsConst { return errors.New("storage item is constant") } return ic.DAO.DeleteStorageItem(stc.ID, key) } // storageGet returns stored key-value pair. func storageGet(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) } key := ic.VM.Estack().Pop().Bytes() si := ic.DAO.GetStorageItem(stc.ID, key) if si != nil && si.Value != nil { ic.VM.Estack().PushVal(si.Value) } else { ic.VM.Estack().PushVal(stackitem.Null{}) } return nil } // storageGetContext returns storage context (scripthash). func storageGetContext(ic *interop.Context) error { return storageGetContextInternal(ic, false) } // storageGetReadOnlyContext returns read-only context (scripthash). func storageGetReadOnlyContext(ic *interop.Context) error { return storageGetContextInternal(ic, true) } // storageGetContextInternal is internal version of storageGetContext and // storageGetReadOnlyContext which allows to specify ReadOnly context flag. func storageGetContextInternal(ic *interop.Context, isReadOnly bool) error { contract, err := ic.GetContract(ic.VM.GetCurrentScriptHash()) if err != nil { return err } sc := &StorageContext{ ID: contract.ID, ReadOnly: isReadOnly, } ic.VM.Estack().PushVal(stackitem.NewInterop(sc)) return nil } func putWithContextAndFlags(ic *interop.Context, stc *StorageContext, key []byte, value []byte, isConst bool) error { if len(key) > MaxStorageKeyLen { return errors.New("key is too big") } if len(value) > MaxStorageValueLen { return errors.New("value is too big") } if stc.ReadOnly { return errors.New("StorageContext is read only") } si := ic.DAO.GetStorageItem(stc.ID, key) if si != nil && si.IsConst { return errors.New("storage item exists and is read-only") } sizeInc := 1 if si == nil { si = &state.StorageItem{} sizeInc = len(key) + len(value) } else if len(value) != 0 { if len(value) <= len(si.Value) { sizeInc = (len(value)-1)/4 + 1 } else { sizeInc = (len(si.Value)-1)/4 + 1 + len(value) - len(si.Value) } } if !ic.VM.AddGas(int64(sizeInc) * ic.Chain.GetPolicer().GetStoragePrice()) { return errGasLimitExceeded } si.Value = value si.IsConst = isConst return ic.DAO.PutStorageItem(stc.ID, key, si) } // storagePutInternal is a unified implementation of storagePut and storagePutEx. func storagePutInternal(ic *interop.Context, getFlag bool) error { stcInterface := ic.VM.Estack().Pop().Value() stc, ok := stcInterface.(*StorageContext) if !ok { return fmt.Errorf("%T is not a StorageContext", stcInterface) } key := ic.VM.Estack().Pop().Bytes() value := ic.VM.Estack().Pop().Bytes() var flag int if getFlag { flag = int(ic.VM.Estack().Pop().BigInt().Int64()) } return putWithContextAndFlags(ic, stc, key, value, int(Constant)&flag != 0) } // storagePut puts key-value pair into the storage. func storagePut(ic *interop.Context) error { return storagePutInternal(ic, false) } // storagePutEx puts key-value pair with given flags into the storage. func storagePutEx(ic *interop.Context) error { return storagePutInternal(ic, true) } // storageContextAsReadOnly sets given context to read-only mode. func storageContextAsReadOnly(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) } if !stc.ReadOnly { stx := &StorageContext{ ID: stc.ID, ReadOnly: true, } stc = stx } ic.VM.Estack().PushVal(stackitem.NewInterop(stc)) return nil } // contractIsStandard checks if contract is standard (sig or multisig) contract. func contractIsStandard(ic *interop.Context) error { h := ic.VM.Estack().Pop().Bytes() u, err := util.Uint160DecodeBytesBE(h) if err != nil { return err } var result bool cs, _ := ic.GetContract(u) if cs != nil { result = vm.IsStandardContract(cs.NEF.Script) } else { if tx, ok := ic.Container.(*transaction.Transaction); ok { for _, witness := range tx.Scripts { if witness.ScriptHash() == u { result = vm.IsStandardContract(witness.VerificationScript) break } } } } ic.VM.Estack().PushVal(result) return nil } // contractCreateMultisigAccount calculates multisig contract scripthash for a // given m and a set of public keys. func contractCreateMultisigAccount(ic *interop.Context) error { m := ic.VM.Estack().Pop().BigInt() if !m.IsInt64() || m.Int64() > math.MaxInt32 { return errors.New("m should fit int32") } arr := ic.VM.Estack().Pop().Array() pubs := make(keys.PublicKeys, len(arr)) for i, pk := range arr { p, err := keys.NewPublicKeyFromBytes(pk.Value().([]byte), elliptic.P256()) if err != nil { return err } pubs[i] = p } script, err := smartcontract.CreateMultiSigRedeemScript(int(m.Int64()), pubs) if err != nil { return err } ic.VM.Estack().PushVal(hash.Hash160(script).BytesBE()) return nil } // contractCreateStandardAccount calculates contract scripthash for a given public key. func contractCreateStandardAccount(ic *interop.Context) error { h := ic.VM.Estack().Pop().Bytes() p, err := keys.NewPublicKeyFromBytes(h, elliptic.P256()) if err != nil { return err } ic.VM.Estack().PushVal(p.GetScriptHash().BytesBE()) return nil } // contractGetCallFlags returns current context calling flags. func contractGetCallFlags(ic *interop.Context) error { ic.VM.Estack().PushVal(ic.VM.Context().GetCallFlags()) return nil }