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,zeroisnull"`
 41	AbsoluteFeeUpdate time.Time          `meddler:"usd_update,utctimez"`
 42	Type              TxType             `meddler:"tx_type"`
 43	// Extra metadata, may be uninitialized
 44	RqTxCompressedData []byte `meddler:"-"` // 253 bits, optional for atomic txs
 45}
 46
 47// TxCompressedData spec:
 48// [ 1 bits  ] toBJJSign // 1 byte
 49// [ 8 bits  ] userFee // 1 byte
 50// [ 40 bits ] nonce // 5 bytes
 51// [ 32 bits ] tokenID // 4 bytes
 52// [ 16 bits ] amountFloat16 // 2 bytes
 53// [ 48 bits ] toIdx // 6 bytes
 54// [ 48 bits ] fromIdx // 6 bytes
 55// [ 16 bits ] chainId // 2 bytes
 56// [ 32 bits ] signatureConstant // 4 bytes
 57// Total bits compressed data:  241 bits // 31 bytes in *big.Int representation
 58func (tx *PoolL2Tx) TxCompressedData() (*big.Int, error) {
 59	// sigconstant
 60	sc, ok := new(big.Int).SetString("3322668559", 10)
 61	if !ok {
 62		return nil, fmt.Errorf("error parsing SignatureConstant")
 63	}
 64
 65	amountFloat16, err := NewFloat16(tx.Amount)
 66	if err != nil {
 67		return nil, err
 68	}
 69	var b [31]byte
 70	toBJJSign := byte(0)
 71	if babyjub.PointCoordSign(tx.ToBJJ.X) {
 72		toBJJSign = byte(1)
 73	}
 74	b[0] = toBJJSign
 75	b[1] = byte(tx.Fee)
 76	nonceBytes, err := tx.Nonce.Bytes()
 77	if err != nil {
 78		return nil, err
 79	}
 80	copy(b[2:7], nonceBytes[:])
 81	copy(b[7:11], tx.TokenID.Bytes())
 82	copy(b[11:13], amountFloat16.Bytes())
 83	toIdxBytes, err := tx.ToIdx.Bytes()
 84	if err != nil {
 85		return nil, err
 86	}
 87	copy(b[13:19], toIdxBytes[:])
 88	fromIdxBytes, err := tx.FromIdx.Bytes()
 89	if err != nil {
 90		return nil, err
 91	}
 92	copy(b[19:25], fromIdxBytes[:])
 93	copy(b[25:27], []byte{0, 1, 0, 0}) // TODO check js implementation (unexpected behaviour from test vector generated from js)
 94	copy(b[27:31], sc.Bytes())
 95
 96	bi := new(big.Int).SetBytes(b[:])
 97	return bi, nil
 98}
 99
100// TxCompressedDataV2 spec:
101// [ 1 bits  ] toBJJSign // 1 byte
102// [ 8 bits  ] userFee // 1 byte
103// [ 40 bits ] nonce // 5 bytes
104// [ 32 bits ] tokenID // 4 bytes
105// [ 16 bits ] amountFloat16 // 2 bytes
106// [ 48 bits ] toIdx // 6 bytes
107// [ 48 bits ] fromIdx // 6 bytes
108// Total bits compressed data:  193 bits // 25 bytes in *big.Int representation
109func (tx *PoolL2Tx) TxCompressedDataV2() (*big.Int, error) {
110	amountFloat16, err := NewFloat16(tx.Amount)
111	if err != nil {
112		return nil, err
113	}
114	var b [25]byte
115	toBJJSign := byte(0)
116	if babyjub.PointCoordSign(tx.ToBJJ.X) {
117		toBJJSign = byte(1)
118	}
119	b[0] = toBJJSign
120	b[1] = byte(tx.Fee)
121	nonceBytes, err := tx.Nonce.Bytes()
122	if err != nil {
123		return nil, err
124	}
125	copy(b[2:7], nonceBytes[:])
126	copy(b[7:11], tx.TokenID.Bytes())
127	copy(b[11:13], amountFloat16.Bytes())
128	toIdxBytes, err := tx.ToIdx.Bytes()
129	if err != nil {
130		return nil, err
131	}
132	copy(b[13:19], toIdxBytes[:])
133	fromIdxBytes, err := tx.FromIdx.Bytes()
134	if err != nil {
135		return nil, err
136	}
137	copy(b[19:25], fromIdxBytes[:])
138
139	bi := new(big.Int).SetBytes(b[:])
140	return bi, nil
141}
142
143// HashToSign returns the computed Poseidon hash from the *PoolL2Tx that will be signed by the sender.
144func (tx *PoolL2Tx) HashToSign() (*big.Int, error) {
145	toCompressedData, err := tx.TxCompressedData()
146	if err != nil {
147		return nil, err
148	}
149	toEthAddr := EthAddrToBigInt(tx.ToEthAddr)
150	toBJJAy := tx.ToBJJ.Y
151	rqTxCompressedDataV2, err := tx.TxCompressedDataV2()
152	if err != nil {
153		return nil, err
154	}
155
156	return poseidon.Hash([]*big.Int{toCompressedData, toEthAddr, toBJJAy, rqTxCompressedDataV2, EthAddrToBigInt(tx.RqToEthAddr), tx.RqToBJJ.Y})
157}
158
159// VerifySignature returns true if the signature verification is correct for the given PublicKey
160func (tx *PoolL2Tx) VerifySignature(pk *babyjub.PublicKey) bool {
161	h, err := tx.HashToSign()
162	if err != nil {
163		return false
164	}
165	return pk.VerifyPoseidon(h, tx.Signature)
166}
167
168// L2Tx returns a *L2Tx from the PoolL2Tx
169func (tx *PoolL2Tx) L2Tx() *L2Tx {
170	return &L2Tx{
171		TxID:     tx.TxID,
172		BatchNum: tx.BatchNum,
173		FromIdx:  tx.FromIdx,
174		ToIdx:    tx.ToIdx,
175		Amount:   tx.Amount,
176		Fee:      tx.Fee,
177		Nonce:    tx.Nonce,
178		Type:     tx.Type,
179	}
180}
181
182// Tx returns a *Tx from the PoolL2Tx
183func (tx *PoolL2Tx) Tx() *Tx {
184	return &Tx{
185		TxID:    tx.TxID,
186		FromIdx: tx.FromIdx,
187		ToIdx:   tx.ToIdx,
188		Amount:  tx.Amount,
189		Nonce:   tx.Nonce,
190		Fee:     tx.Fee,
191		Type:    tx.Type,
192	}
193}
194
195// PoolL2TxsToL2Txs returns an array of []*L2Tx from an array of []*PoolL2Tx
196func PoolL2TxsToL2Txs(txs []*PoolL2Tx) []*L2Tx {
197	var r []*L2Tx
198	for _, tx := range txs {
199		r = append(r, tx.L2Tx())
200	}
201	return r
202}
203
204// PoolL2TxState is a struct that represents the status of a L2 transaction
205type PoolL2TxState string
206
207const (
208	// PoolL2TxStatePending represents a valid L2Tx that hasn't started the forging process
209	PoolL2TxStatePending PoolL2TxState = "pend"
210	// PoolL2TxStateForging represents a valid L2Tx that has started the forging process
211	PoolL2TxStateForging PoolL2TxState = "fing"
212	// PoolL2TxStateForged represents a L2Tx that has already been forged
213	PoolL2TxStateForged PoolL2TxState = "fged"
214	// PoolL2TxStateInvalid represents a L2Tx that has been invalidated
215	PoolL2TxStateInvalid PoolL2TxState = "invl"
216)