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package common
import (
"errors"
"fmt"
"math/big"
"time"
ethCommon "github.com/ethereum/go-ethereum/common"
"github.com/iden3/go-iden3-crypto/babyjub"
"github.com/iden3/go-iden3-crypto/poseidon"
)
// PoolL2Tx is a struct that represents a L2Tx sent by an account to the coordinator hat is waiting to be forged
type PoolL2Tx struct {
// Stored in DB: mandatory fileds
// TxID (12 bytes) for L2Tx is:
// bytes: | 1 | 6 | 5 |
// values: | type | FromIdx | Nonce |
TxID TxID `meddler:"tx_id"`
FromIdx Idx `meddler:"from_idx"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
ToIdx *Idx `meddler:"to_idx"` // ToIdx is ignored in L1Tx/Deposit, but used in the L1Tx/DepositAndTransfer
ToEthAddr *ethCommon.Address `meddler:"to_eth_addr"`
ToBJJ *babyjub.PublicKey `meddler:"to_bjj"` // TODO: stop using json, use scanner/valuer
TokenID TokenID `meddler:"token_id"`
Amount *big.Int `meddler:"amount,bigint"` // TODO: change to float16
AmountFloat float64 `meddler:"amount_f"` // TODO: change to float16
USD *float64 `meddler:"value_usd"` // TODO: change to float16
Fee FeeSelector `meddler:"fee"`
Nonce Nonce `meddler:"nonce"` // effective 40 bits used
State PoolL2TxState `meddler:"state"`
Signature *babyjub.Signature `meddler:"signature"` // tx signature
Timestamp time.Time `meddler:"timestamp,utctime"` // time when added to the tx pool
// Stored in DB: optional fileds, may be uninitialized
BatchNum *BatchNum `meddler:"batch_num"` // batchNum in which this tx was forged. Presence indicates "forged" state.
RqFromIdx *Idx `meddler:"rq_from_idx"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
RqToIdx *Idx `meddler:"rq_to_idx"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
RqToEthAddr *ethCommon.Address `meddler:"rq_to_eth_addr"`
RqToBJJ *babyjub.PublicKey `meddler:"rq_to_bjj"` // TODO: stop using json, use scanner/valuer
RqTokenID *TokenID `meddler:"rq_token_id"`
RqAmount *big.Int `meddler:"rq_amount,bigintnull"` // TODO: change to float16
RqFee *FeeSelector `meddler:"rq_fee"`
RqNonce *uint64 `meddler:"rq_nonce"` // effective 48 bits used
AbsoluteFee *float64 `meddler:"fee_usd"`
AbsoluteFeeUpdate *time.Time `meddler:"usd_update,utctime"`
Type TxType `meddler:"tx_type"`
// Extra metadata, may be uninitialized
RqTxCompressedData []byte `meddler:"-"` // 253 bits, optional for atomic txs
}
// NewPoolL2Tx returns the given L2Tx with the TxId & Type parameters calculated
// from the L2Tx values
func NewPoolL2Tx(poolL2Tx *PoolL2Tx) (*PoolL2Tx, error) {
// calculate TxType
var txType TxType
if poolL2Tx.ToIdx == nil || *poolL2Tx.ToIdx == Idx(0) {
txType = TxTypeTransfer
} else if *poolL2Tx.ToIdx == Idx(1) {
txType = TxTypeExit
} else if *poolL2Tx.ToIdx >= IdxUserThreshold {
txType = TxTypeTransfer
} else {
return poolL2Tx, fmt.Errorf("Can not determine type of PoolL2Tx, invalid ToIdx value: %d", poolL2Tx.ToIdx)
}
// if TxType!=poolL2Tx.TxType return error
if poolL2Tx.Type != "" && poolL2Tx.Type != txType {
return poolL2Tx, fmt.Errorf("PoolL2Tx.Type: %s, should be: %s", poolL2Tx.Type, txType)
}
poolL2Tx.Type = txType
var txid [TxIDLen]byte
txid[0] = TxIDPrefixL2Tx
fromIdxBytes, err := poolL2Tx.FromIdx.Bytes()
if err != nil {
return poolL2Tx, err
}
copy(txid[1:7], fromIdxBytes[:])
nonceBytes, err := poolL2Tx.Nonce.Bytes()
if err != nil {
return poolL2Tx, err
}
copy(txid[7:12], nonceBytes[:])
poolL2Tx.TxID = TxID(txid)
return poolL2Tx, nil
}
// TxCompressedData spec:
// [ 1 bits ] toBJJSign // 1 byte
// [ 8 bits ] userFee // 1 byte
// [ 40 bits ] nonce // 5 bytes
// [ 32 bits ] tokenID // 4 bytes
// [ 16 bits ] amountFloat16 // 2 bytes
// [ 48 bits ] toIdx // 6 bytes
// [ 48 bits ] fromIdx // 6 bytes
// [ 16 bits ] chainId // 2 bytes
// [ 32 bits ] signatureConstant // 4 bytes
// Total bits compressed data: 241 bits // 31 bytes in *big.Int representation
func (tx *PoolL2Tx) TxCompressedData() (*big.Int, error) {
// sigconstant
sc, ok := new(big.Int).SetString("3322668559", 10)
if !ok {
return nil, fmt.Errorf("error parsing SignatureConstant")
}
amountFloat16, err := NewFloat16(tx.Amount)
if err != nil {
return nil, err
}
var b [31]byte
toBJJSign := byte(0)
if babyjub.PointCoordSign(tx.ToBJJ.X) {
toBJJSign = byte(1)
}
b[0] = toBJJSign
b[1] = byte(tx.Fee)
nonceBytes, err := tx.Nonce.Bytes()
if err != nil {
return nil, err
}
copy(b[2:7], nonceBytes[:])
copy(b[7:11], tx.TokenID.Bytes())
copy(b[11:13], amountFloat16.Bytes())
toIdxBytes, err := tx.ToIdx.Bytes()
if err != nil {
return nil, err
}
copy(b[13:19], toIdxBytes[:])
fromIdxBytes, err := tx.FromIdx.Bytes()
if err != nil {
return nil, err
}
copy(b[19:25], fromIdxBytes[:])
copy(b[25:27], []byte{0, 1, 0, 0}) // TODO check js implementation (unexpected behaviour from test vector generated from js)
copy(b[27:31], sc.Bytes())
bi := new(big.Int).SetBytes(b[:])
return bi, nil
}
// TxCompressedDataV2 spec:
// [ 1 bits ] toBJJSign // 1 byte
// [ 8 bits ] userFee // 1 byte
// [ 40 bits ] nonce // 5 bytes
// [ 32 bits ] tokenID // 4 bytes
// [ 16 bits ] amountFloat16 // 2 bytes
// [ 48 bits ] toIdx // 6 bytes
// [ 48 bits ] fromIdx // 6 bytes
// Total bits compressed data: 193 bits // 25 bytes in *big.Int representation
func (tx *PoolL2Tx) TxCompressedDataV2() (*big.Int, error) {
amountFloat16, err := NewFloat16(tx.Amount)
if err != nil {
return nil, err
}
var b [25]byte
toBJJSign := byte(0)
if babyjub.PointCoordSign(tx.ToBJJ.X) {
toBJJSign = byte(1)
}
b[0] = toBJJSign
b[1] = byte(tx.Fee)
nonceBytes, err := tx.Nonce.Bytes()
if err != nil {
return nil, err
}
copy(b[2:7], nonceBytes[:])
copy(b[7:11], tx.TokenID.Bytes())
copy(b[11:13], amountFloat16.Bytes())
toIdxBytes, err := tx.ToIdx.Bytes()
if err != nil {
return nil, err
}
copy(b[13:19], toIdxBytes[:])
fromIdxBytes, err := tx.FromIdx.Bytes()
if err != nil {
return nil, err
}
copy(b[19:25], fromIdxBytes[:])
bi := new(big.Int).SetBytes(b[:])
return bi, nil
}
// HashToSign returns the computed Poseidon hash from the *PoolL2Tx that will be signed by the sender.
func (tx *PoolL2Tx) HashToSign() (*big.Int, error) {
toCompressedData, err := tx.TxCompressedData()
if err != nil {
return nil, err
}
toEthAddr := big.NewInt(0)
if tx.ToEthAddr != nil {
toEthAddr = EthAddrToBigInt(*tx.ToEthAddr)
}
rqToEthAddr := big.NewInt(0)
if tx.RqToEthAddr != nil {
rqToEthAddr = EthAddrToBigInt(*tx.RqToEthAddr)
}
toBJJAy := tx.ToBJJ.Y
rqTxCompressedDataV2, err := tx.TxCompressedDataV2()
if err != nil {
return nil, err
}
return poseidon.Hash([]*big.Int{toCompressedData, toEthAddr, toBJJAy, rqTxCompressedDataV2, rqToEthAddr, tx.RqToBJJ.Y})
}
// VerifySignature returns true if the signature verification is correct for the given PublicKey
func (tx *PoolL2Tx) VerifySignature(pk *babyjub.PublicKey) bool {
h, err := tx.HashToSign()
if err != nil {
return false
}
return pk.VerifyPoseidon(h, tx.Signature)
}
// L2Tx returns a *L2Tx from the PoolL2Tx
func (tx *PoolL2Tx) L2Tx() (*L2Tx, error) {
if tx.ToIdx == nil || tx.BatchNum == nil {
return nil, errors.New("PoolL2Tx must have ToIdx != nil and BatchNum != nil in order to be able to transform to Tx")
}
return &L2Tx{
TxID: tx.TxID,
BatchNum: *tx.BatchNum,
FromIdx: tx.FromIdx,
ToIdx: *tx.ToIdx,
Amount: tx.Amount,
Fee: tx.Fee,
Nonce: tx.Nonce,
Type: tx.Type,
}, nil
}
// Tx returns a *Tx from the PoolL2Tx
func (tx *PoolL2Tx) Tx() (*Tx, error) {
if tx.ToIdx == nil {
return nil, errors.New("PoolL2Tx must have ToIdx != nil in order to be able to transform to Tx")
}
fromIdx := new(Idx)
*fromIdx = tx.FromIdx
return &Tx{
TxID: tx.TxID,
FromIdx: fromIdx,
ToIdx: tx.ToIdx,
Amount: tx.Amount,
Nonce: &tx.Nonce,
Fee: &tx.Fee,
Type: tx.Type,
}, nil
}
// PoolL2TxsToL2Txs returns an array of []*L2Tx from an array of []*PoolL2Tx
func PoolL2TxsToL2Txs(txs []*PoolL2Tx) ([]*L2Tx, error) {
var r []*L2Tx
for _, poolTx := range txs {
tx, err := poolTx.L2Tx()
if err != nil {
return nil, err
}
r = append(r, tx)
}
return r, nil
}
// PoolL2TxState is a struct that represents the status of a L2 transaction
type PoolL2TxState string
const (
// PoolL2TxStatePending represents a valid L2Tx that hasn't started the forging process
PoolL2TxStatePending PoolL2TxState = "pend"
// PoolL2TxStateForging represents a valid L2Tx that has started the forging process
PoolL2TxStateForging PoolL2TxState = "fing"
// PoolL2TxStateForged represents a L2Tx that has already been forged
PoolL2TxStateForged PoolL2TxState = "fged"
// PoolL2TxStateInvalid represents a L2Tx that has been invalidated
PoolL2TxStateInvalid PoolL2TxState = "invl"
)