neoneo-go/pkg/rpc/txBuilder.go

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package rpc
import (
"bytes"
"errors"
"fmt"
"strconv"
"github.com/CityOfZion/neo-go/pkg/core/transaction"
"github.com/CityOfZion/neo-go/pkg/crypto"
"github.com/CityOfZion/neo-go/pkg/crypto/keys"
"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, address, amount, balancer = params.wif, params.assetID, params.address, params.value, params.balancer
)
fromAddress = wif.PrivateKey.Address()
if fromAddressHash, err = crypto.Uint160DecodeAddress(fromAddress); err != nil {
return nil, errs.Wrapf(err, "Failed to take script hash from address: %v", fromAddress)
}
if toAddressHash, err = crypto.Uint160DecodeAddress(address); err != nil {
return nil, errs.Wrapf(err, "Failed to take script hash from address: %v", address)
}
tx.Attributes = append(tx.Attributes,
&transaction.Attribute{
Usage: transaction.Script,
Data: fromAddressHash.Bytes(),
})
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, address string, assetID util.Uint256, amount util.Fixed8, balancer BalanceGetter) error {
scriptHash, err := crypto.Uint160DecodeAddress(address)
if err != nil {
return errs.Wrapf(err, "failed to take script hash from address: %v", address)
}
inputs, spent, err := balancer.CalculateInputs(address, 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.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) {
const (
pushbytes64 = 0x40
)
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{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.Bytes()); err != nil {
return err
}
case Hash256:
hash, err := fp.Value.GetUint256()
if err != nil {
return err
}
if err := vm.EmitBytes(script, hash.Bytes()); 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
}