package rpc import ( "bytes" "errors" "fmt" "strconv" "github.com/CityOfZion/neo-go/pkg/core/transaction" "github.com/CityOfZion/neo-go/pkg/crypto/keys" "github.com/CityOfZion/neo-go/pkg/encoding/address" "github.com/CityOfZion/neo-go/pkg/io" "github.com/CityOfZion/neo-go/pkg/smartcontract" "github.com/CityOfZion/neo-go/pkg/util" "github.com/CityOfZion/neo-go/pkg/vm" "github.com/CityOfZion/neo-go/pkg/vm/opcode" errs "github.com/pkg/errors" ) // CreateRawContractTransaction returns contract-type Transaction built from specified parameters. func CreateRawContractTransaction(params ContractTxParams) (*transaction.Transaction, error) { var ( err error tx = transaction.NewContractTX() toAddressHash, fromAddressHash util.Uint160 fromAddress string receiverOutput *transaction.Output wif, assetID, toAddress, amount, balancer = params.wif, params.assetID, params.address, params.value, params.balancer ) fromAddress = wif.PrivateKey.Address() if fromAddressHash, err = address.DecodeUint160(fromAddress); err != nil { return nil, errs.Wrapf(err, "Failed to take script hash from address: %v", fromAddress) } if toAddressHash, err = address.DecodeUint160(toAddress); err != nil { return nil, errs.Wrapf(err, "Failed to take script hash from address: %v", toAddress) } tx.Attributes = append(tx.Attributes, transaction.Attribute{ Usage: transaction.Script, Data: fromAddressHash.BytesBE(), }) if err = AddInputsAndUnspentsToTx(tx, fromAddress, assetID, amount, balancer); err != nil { return nil, errs.Wrap(err, "failed to add inputs and unspents to transaction") } receiverOutput = transaction.NewOutput(assetID, amount, toAddressHash) tx.AddOutput(receiverOutput) if err = SignTx(tx, &wif); err != nil { return nil, errs.Wrap(err, "failed to sign tx") } return tx, nil } // AddInputsAndUnspentsToTx adds inputs needed to transaction and one output // with change. func AddInputsAndUnspentsToTx(tx *transaction.Transaction, addr string, assetID util.Uint256, amount util.Fixed8, balancer BalanceGetter) error { scriptHash, err := address.DecodeUint160(addr) if err != nil { return errs.Wrapf(err, "failed to take script hash from address: %v", addr) } inputs, spent, err := balancer.CalculateInputs(addr, assetID, amount) if err != nil { return errs.Wrap(err, "failed to get inputs") } for _, input := range inputs { tx.AddInput(&input) } if senderUnspent := spent - amount; senderUnspent > 0 { senderOutput := transaction.NewOutput(assetID, senderUnspent, scriptHash) tx.AddOutput(senderOutput) } return nil } // SignTx signs given transaction in-place using given key. func SignTx(tx *transaction.Transaction, wif *keys.WIF) error { var witness transaction.Witness var err error if witness.InvocationScript, err = GetInvocationScript(tx, wif); err != nil { return errs.Wrap(err, "failed to create invocation script") } witness.VerificationScript = wif.PrivateKey.PublicKey().GetVerificationScript() tx.Scripts = append(tx.Scripts, witness) tx.Hash() return nil } // GetInvocationScript returns NEO VM script containing transaction signature. func GetInvocationScript(tx *transaction.Transaction, wif *keys.WIF) ([]byte, error) { var ( err error buf = io.NewBufBinWriter() signature []byte ) tx.EncodeBinary(buf.BinWriter) if buf.Err != nil { return nil, errs.Wrap(buf.Err, "Failed to encode transaction to binary") } data := buf.Bytes() signature, err = wif.PrivateKey.Sign(data[:(len(data) - 1)]) if err != nil { return nil, errs.Wrap(err, "Failed ti sign transaction with private key") } return append([]byte{byte(opcode.PUSHBYTES64)}, signature...), nil } // CreateDeploymentScript returns a script that deploys given smart contract // with its metadata. func CreateDeploymentScript(avm []byte, contract *ContractDetails) ([]byte, error) { var props smartcontract.PropertyState script := new(bytes.Buffer) if err := vm.EmitBytes(script, []byte(contract.Description)); err != nil { return nil, err } if err := vm.EmitBytes(script, []byte(contract.Email)); err != nil { return nil, err } if err := vm.EmitBytes(script, []byte(contract.Author)); err != nil { return nil, err } if err := vm.EmitBytes(script, []byte(contract.Version)); err != nil { return nil, err } if err := vm.EmitBytes(script, []byte(contract.ProjectName)); err != nil { return nil, err } if contract.HasStorage { props |= smartcontract.HasStorage } if contract.HasDynamicInvocation { props |= smartcontract.HasDynamicInvoke } if contract.IsPayable { props |= smartcontract.IsPayable } if err := vm.EmitInt(script, int64(props)); err != nil { return nil, err } if err := vm.EmitInt(script, int64(contract.ReturnType)); err != nil { return nil, err } params := make([]byte, len(contract.Parameters)) for k := range contract.Parameters { params[k] = byte(contract.Parameters[k]) } if err := vm.EmitBytes(script, params); err != nil { return nil, err } if err := vm.EmitBytes(script, avm); err != nil { return nil, err } if err := vm.EmitSyscall(script, "Neo.Contract.Create"); err != nil { return nil, err } return script.Bytes(), nil } // expandArrayIntoScript pushes all FuncParam parameters from the given array // into the given buffer in reverse order. func expandArrayIntoScript(script *bytes.Buffer, slice []Param) error { for j := len(slice) - 1; j >= 0; j-- { fp, err := slice[j].GetFuncParam() if err != nil { return err } switch fp.Type { case ByteArray, Signature: str, err := fp.Value.GetBytesHex() if err != nil { return err } if err := vm.EmitBytes(script, str); err != nil { return err } case String: str, err := fp.Value.GetString() if err != nil { return err } if err := vm.EmitString(script, str); err != nil { return err } case Hash160: hash, err := fp.Value.GetUint160FromHex() if err != nil { return err } if err := vm.EmitBytes(script, hash.BytesBE()); err != nil { return err } case Hash256: hash, err := fp.Value.GetUint256() if err != nil { return err } if err := vm.EmitBytes(script, hash.BytesBE()); err != nil { return err } case PublicKey: str, err := fp.Value.GetString() if err != nil { return err } key, err := keys.NewPublicKeyFromString(string(str)) if err != nil { return err } if err := vm.EmitBytes(script, key.Bytes()); err != nil { return err } case Integer: val, err := fp.Value.GetInt() if err != nil { return err } if err := vm.EmitInt(script, int64(val)); err != nil { return err } case Boolean: str, err := fp.Value.GetString() if err != nil { return err } switch str { case "true": err = vm.EmitInt(script, 1) case "false": err = vm.EmitInt(script, 0) default: err = errors.New("wrong boolean value") } if err != nil { return err } default: return fmt.Errorf("parameter type %v is not supported", fp.Type) } } return nil } // CreateFunctionInvocationScript creates a script to invoke given contract with // given parameters. func CreateFunctionInvocationScript(contract util.Uint160, params Params) ([]byte, error) { script := new(bytes.Buffer) for i := len(params) - 1; i >= 0; i-- { switch params[i].Type { case stringT: if err := vm.EmitString(script, params[i].String()); err != nil { return nil, err } case numberT: num, err := params[i].GetInt() if err != nil { return nil, err } if err := vm.EmitString(script, strconv.Itoa(num)); err != nil { return nil, err } case arrayT: slice, err := params[i].GetArray() if err != nil { return nil, err } err = expandArrayIntoScript(script, slice) if err != nil { return nil, err } err = vm.EmitInt(script, int64(len(slice))) if err != nil { return nil, err } err = vm.EmitOpcode(script, opcode.PACK) if err != nil { return nil, err } } } if err := vm.EmitAppCall(script, contract, false); err != nil { return nil, err } return script.Bytes(), nil } // CreateInvocationScript creates a script to invoke given contract with // given parameters. It differs from CreateFunctionInvocationScript in that it // expects one array of FuncParams and expands it onto the stack as independent // elements. func CreateInvocationScript(contract util.Uint160, funcParams []Param) ([]byte, error) { script := new(bytes.Buffer) err := expandArrayIntoScript(script, funcParams) if err != nil { return nil, err } if err = vm.EmitAppCall(script, contract, false); err != nil { return nil, err } return script.Bytes(), nil }