arnaucube
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hermez-node/common/pooll2tx.go
common/pooll2tx.goRaw
  1package common
  2
  3import (
  4	"fmt"
  5	"math/big"
  6	"time"
  7
  8	ethCommon "github.com/ethereum/go-ethereum/common"
  9	"github.com/iden3/go-iden3-crypto/babyjub"
 10	"github.com/iden3/go-iden3-crypto/poseidon"
 11)
 12
 13// PoolL2Tx is a struct that represents a L2Tx sent by an account to the coordinator hat is waiting to be forged
 14type PoolL2Tx struct {
 15	// Stored in DB: mandatory fileds
 16	TxID        TxID               `meddler:"tx_id"`
 17	FromIdx     Idx                `meddler:"from_idx"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
 18	ToIdx       Idx                `meddler:"to_idx"`   // ToIdx is ignored in L1Tx/Deposit, but used in the L1Tx/DepositAndTransfer
 19	ToEthAddr   ethCommon.Address  `meddler:"to_eth_addr"`
 20	ToBJJ       *babyjub.PublicKey `meddler:"to_bjj"` // TODO: stop using json, use scanner/valuer
 21	TokenID     TokenID            `meddler:"token_id"`
 22	Amount      *big.Int           `meddler:"amount,bigint"` // TODO: change to float16
 23	AmountFloat float64            `meddler:"amount_f"`      // TODO: change to float16
 24	USD         *float64           `meddler:"value_usd"`     // TODO: change to float16
 25	Fee         FeeSelector        `meddler:"fee"`
 26	Nonce       Nonce              `meddler:"nonce"` // effective 40 bits used
 27	State       PoolL2TxState      `meddler:"state"`
 28	Signature   *babyjub.Signature `meddler:"signature"`         // tx signature
 29	Timestamp   time.Time          `meddler:"timestamp,utctime"` // time when added to the tx pool
 30	// Stored in DB: optional fileds, may be uninitialized
 31	BatchNum          BatchNum           `meddler:"batch_num,zeroisnull"`   // batchNum in which this tx was forged. Presence indicates "forged" state.
 32	RqFromIdx         Idx                `meddler:"rq_from_idx,zeroisnull"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
 33	RqToIdx           Idx                `meddler:"rq_to_idx,zeroisnull"`   // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
 34	RqToEthAddr       ethCommon.Address  `meddler:"rq_to_eth_addr"`
 35	RqToBJJ           *babyjub.PublicKey `meddler:"rq_to_bjj"` // TODO: stop using json, use scanner/valuer
 36	RqTokenID         TokenID            `meddler:"rq_token_id,zeroisnull"`
 37	RqAmount          *big.Int           `meddler:"rq_amount,bigintnull"` // TODO: change to float16
 38	RqFee             FeeSelector        `meddler:"rq_fee,zeroisnull"`
 39	RqNonce           uint64             `meddler:"rq_nonce,zeroisnull"` // effective 48 bits used
 40	AbsoluteFee       *float64           `meddler:"fee_usd"`
 41	AbsoluteFeeUpdate *time.Time         `meddler:"usd_update,utctime"`
 42	Type              TxType             `meddler:"tx_type"`
 43	// Extra metadata, may be uninitialized
 44	RqTxCompressedData []byte `meddler:"-"` // 253 bits, optional for atomic txs
 45	TokenSymbol        string `meddler:"token_symbol"`
 46}
 47
 48// TxCompressedData spec:
 49// [ 1 bits  ] toBJJSign // 1 byte
 50// [ 8 bits  ] userFee // 1 byte
 51// [ 40 bits ] nonce // 5 bytes
 52// [ 32 bits ] tokenID // 4 bytes
 53// [ 16 bits ] amountFloat16 // 2 bytes
 54// [ 48 bits ] toIdx // 6 bytes
 55// [ 48 bits ] fromIdx // 6 bytes
 56// [ 16 bits ] chainId // 2 bytes
 57// [ 32 bits ] signatureConstant // 4 bytes
 58// Total bits compressed data:  241 bits // 31 bytes in *big.Int representation
 59func (tx *PoolL2Tx) TxCompressedData() (*big.Int, error) {
 60	// sigconstant
 61	sc, ok := new(big.Int).SetString("3322668559", 10)
 62	if !ok {
 63		return nil, fmt.Errorf("error parsing SignatureConstant")
 64	}
 65
 66	amountFloat16, err := NewFloat16(tx.Amount)
 67	if err != nil {
 68		return nil, err
 69	}
 70	var b [31]byte
 71	toBJJSign := byte(0)
 72	if babyjub.PointCoordSign(tx.ToBJJ.X) {
 73		toBJJSign = byte(1)
 74	}
 75	b[0] = toBJJSign
 76	b[1] = byte(tx.Fee)
 77	nonceBytes, err := tx.Nonce.Bytes()
 78	if err != nil {
 79		return nil, err
 80	}
 81	copy(b[2:7], nonceBytes[:])
 82	copy(b[7:11], tx.TokenID.Bytes())
 83	copy(b[11:13], amountFloat16.Bytes())
 84	toIdxBytes, err := tx.ToIdx.Bytes()
 85	if err != nil {
 86		return nil, err
 87	}
 88	copy(b[13:19], toIdxBytes[:])
 89	fromIdxBytes, err := tx.FromIdx.Bytes()
 90	if err != nil {
 91		return nil, err
 92	}
 93	copy(b[19:25], fromIdxBytes[:])
 94	copy(b[25:27], []byte{0, 1, 0, 0}) // TODO check js implementation (unexpected behaviour from test vector generated from js)
 95	copy(b[27:31], sc.Bytes())
 96
 97	bi := new(big.Int).SetBytes(b[:])
 98	return bi, nil
 99}
100
101// TxCompressedDataV2 spec:
102// [ 1 bits  ] toBJJSign // 1 byte
103// [ 8 bits  ] userFee // 1 byte
104// [ 40 bits ] nonce // 5 bytes
105// [ 32 bits ] tokenID // 4 bytes
106// [ 16 bits ] amountFloat16 // 2 bytes
107// [ 48 bits ] toIdx // 6 bytes
108// [ 48 bits ] fromIdx // 6 bytes
109// Total bits compressed data:  193 bits // 25 bytes in *big.Int representation
110func (tx *PoolL2Tx) TxCompressedDataV2() (*big.Int, error) {
111	amountFloat16, err := NewFloat16(tx.Amount)
112	if err != nil {
113		return nil, err
114	}
115	var b [25]byte
116	toBJJSign := byte(0)
117	if babyjub.PointCoordSign(tx.ToBJJ.X) {
118		toBJJSign = byte(1)
119	}
120	b[0] = toBJJSign
121	b[1] = byte(tx.Fee)
122	nonceBytes, err := tx.Nonce.Bytes()
123	if err != nil {
124		return nil, err
125	}
126	copy(b[2:7], nonceBytes[:])
127	copy(b[7:11], tx.TokenID.Bytes())
128	copy(b[11:13], amountFloat16.Bytes())
129	toIdxBytes, err := tx.ToIdx.Bytes()
130	if err != nil {
131		return nil, err
132	}
133	copy(b[13:19], toIdxBytes[:])
134	fromIdxBytes, err := tx.FromIdx.Bytes()
135	if err != nil {
136		return nil, err
137	}
138	copy(b[19:25], fromIdxBytes[:])
139
140	bi := new(big.Int).SetBytes(b[:])
141	return bi, nil
142}
143
144// HashToSign returns the computed Poseidon hash from the *PoolL2Tx that will be signed by the sender.
145func (tx *PoolL2Tx) HashToSign() (*big.Int, error) {
146	toCompressedData, err := tx.TxCompressedData()
147	if err != nil {
148		return nil, err
149	}
150	toEthAddr := EthAddrToBigInt(tx.ToEthAddr)
151	toBJJAy := tx.ToBJJ.Y
152	rqTxCompressedDataV2, err := tx.TxCompressedDataV2()
153	if err != nil {
154		return nil, err
155	}
156
157	return poseidon.Hash([]*big.Int{toCompressedData, toEthAddr, toBJJAy, rqTxCompressedDataV2, EthAddrToBigInt(tx.RqToEthAddr), tx.RqToBJJ.Y})
158}
159
160// VerifySignature returns true if the signature verification is correct for the given PublicKey
161func (tx *PoolL2Tx) VerifySignature(pk *babyjub.PublicKey) bool {
162	h, err := tx.HashToSign()
163	if err != nil {
164		return false
165	}
166	return pk.VerifyPoseidon(h, tx.Signature)
167}
168
169// L2Tx returns a *L2Tx from the PoolL2Tx
170func (tx *PoolL2Tx) L2Tx() *L2Tx {
171	return &L2Tx{
172		TxID:     tx.TxID,
173		BatchNum: tx.BatchNum,
174		FromIdx:  tx.FromIdx,
175		ToIdx:    tx.ToIdx,
176		Amount:   tx.Amount,
177		Fee:      tx.Fee,
178		Nonce:    tx.Nonce,
179		Type:     tx.Type,
180	}
181}
182
183// Tx returns a *Tx from the PoolL2Tx
184func (tx *PoolL2Tx) Tx() *Tx {
185	return &Tx{
186		TxID:    tx.TxID,
187		FromIdx: tx.FromIdx,
188		ToIdx:   tx.ToIdx,
189		Amount:  tx.Amount,
190		Nonce:   &tx.Nonce,
191		Fee:     &tx.Fee,
192		Type:    tx.Type,
193	}
194}
195
196// PoolL2TxsToL2Txs returns an array of []*L2Tx from an array of []*PoolL2Tx
197func PoolL2TxsToL2Txs(txs []*PoolL2Tx) []*L2Tx {
198	var r []*L2Tx
199	for _, tx := range txs {
200		r = append(r, tx.L2Tx())
201	}
202	return r
203}
204
205// PoolL2TxState is a struct that represents the status of a L2 transaction
206type PoolL2TxState string
207
208const (
209	// PoolL2TxStatePending represents a valid L2Tx that hasn't started the forging process
210	PoolL2TxStatePending PoolL2TxState = "pend"
211	// PoolL2TxStateForging represents a valid L2Tx that has started the forging process
212	PoolL2TxStateForging PoolL2TxState = "fing"
213	// PoolL2TxStateForged represents a L2Tx that has already been forged
214	PoolL2TxStateForged PoolL2TxState = "fged"
215	// PoolL2TxStateInvalid represents a L2Tx that has been invalidated
216	PoolL2TxStateInvalid PoolL2TxState = "invl"
217)