arnaucube
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hermez-node/common/pooll2tx.go
common/pooll2tx.goRaw
  1package common
  2
  3import (
  4	"encoding/binary"
  5	"fmt"
  6	"math/big"
  7	"time"
  8
  9	ethCommon "github.com/ethereum/go-ethereum/common"
 10	"github.com/hermeznetwork/hermez-node/utils"
 11	"github.com/iden3/go-iden3-crypto/babyjub"
 12	"github.com/iden3/go-iden3-crypto/poseidon"
 13)
 14
 15// Nonce represents the nonce value in a uint64, which has the method Bytes that returns a byte array of length 5 (40 bits).
 16type Nonce uint64
 17
 18// Bytes returns a byte array of length 5 representing the Nonce
 19func (n Nonce) Bytes() ([5]byte, error) {
 20	if n >= 1099511627776 { // 2**40bits
 21		return [5]byte{}, ErrNonceOverflow
 22	}
 23	var nonceBytes [8]byte
 24	binary.LittleEndian.PutUint64(nonceBytes[:], uint64(n))
 25	var b [5]byte
 26	copy(b[:], nonceBytes[:5])
 27	return b, nil
 28}
 29
 30// NonceFromBytes returns Nonce from a [5]byte
 31func NonceFromBytes(b [5]byte) Nonce {
 32	var nonceBytes [8]byte
 33	copy(nonceBytes[:], b[:5])
 34	nonce := binary.LittleEndian.Uint64(nonceBytes[:])
 35	return Nonce(nonce)
 36}
 37
 38// PoolL2Tx is a struct that represents a L2Tx sent by an account to the coordinator hat is waiting to be forged
 39type PoolL2Tx struct {
 40	// Stored in DB: mandatory fileds
 41	TxID      TxID               `meddler:"tx_id"`
 42	FromIdx   Idx                `meddler:"from_idx"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
 43	ToIdx     Idx                `meddler:"to_idx"`   // ToIdx is ignored in L1Tx/Deposit, but used in the L1Tx/DepositAndTransfer
 44	ToEthAddr ethCommon.Address  `meddler:"to_eth_addr"`
 45	ToBJJ     *babyjub.PublicKey `meddler:"to_bjj"` // TODO: stop using json, use scanner/valuer
 46	TokenID   TokenID            `meddler:"token_id"`
 47	Amount    *big.Int           `meddler:"amount,bigint"` // TODO: change to float16
 48	Fee       FeeSelector        `meddler:"fee"`
 49	Nonce     Nonce              `meddler:"nonce"` // effective 40 bits used
 50	State     PoolL2TxState      `meddler:"state"`
 51	Signature *babyjub.Signature `meddler:"signature"`         // tx signature
 52	Timestamp time.Time          `meddler:"timestamp,utctime"` // time when added to the tx pool
 53	// Stored in DB: optional fileds, may be uninitialized
 54	BatchNum          BatchNum           `meddler:"batch_num,zeroisnull"`   // batchNum in which this tx was forged. Presence indicates "forged" state.
 55	RqFromIdx         Idx                `meddler:"rq_from_idx,zeroisnull"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
 56	RqToIdx           Idx                `meddler:"rq_to_idx,zeroisnull"`   // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.LoadAmount (deposit)
 57	RqToEthAddr       ethCommon.Address  `meddler:"rq_to_eth_addr"`
 58	RqToBJJ           *babyjub.PublicKey `meddler:"rq_to_bjj"` // TODO: stop using json, use scanner/valuer
 59	RqTokenID         TokenID            `meddler:"rq_token_id,zeroisnull"`
 60	RqAmount          *big.Int           `meddler:"rq_amount,bigintnull"` // TODO: change to float16
 61	RqFee             FeeSelector        `meddler:"rq_fee,zeroisnull"`
 62	RqNonce           uint64             `meddler:"rq_nonce,zeroisnull"` // effective 48 bits used
 63	AbsoluteFee       float64            `meddler:"absolute_fee,zeroisnull"`
 64	AbsoluteFeeUpdate time.Time          `meddler:"absolute_fee_update,utctimez"`
 65	Type              TxType             `meddler:"tx_type"`
 66	// Extra metadata, may be uninitialized
 67	RqTxCompressedData []byte `meddler:"-"` // 253 bits, optional for atomic txs
 68}
 69
 70// TxCompressedData spec:
 71// [ 32 bits ] signatureConstant // 4 bytes: [0:4]
 72// [ 16 bits ] chainId // 2 bytes: [4:6]
 73// [ 48 bits ] fromIdx // 6 bytes: [6:12]
 74// [ 48 bits ] toIdx // 6 bytes: [12:18]
 75// [ 16 bits ] amountFloat16 // 2 bytes: [18:20]
 76// [ 32 bits ] tokenID // 4 bytes: [20:24]
 77// [ 40 bits ] nonce // 5 bytes: [24:29]
 78// [ 8 bits  ] userFee // 1 byte: [29:30]
 79// [ 1 bits  ] toBjjSign // 1 byte: [30:31]
 80// Total bits compressed data:  241 bits // 31 bytes in *big.Int representation
 81func (tx *PoolL2Tx) TxCompressedData() (*big.Int, error) {
 82	// sigconstant
 83	sc, ok := new(big.Int).SetString("3322668559", 10)
 84	if !ok {
 85		return nil, fmt.Errorf("error parsing SignatureConstant")
 86	}
 87
 88	amountFloat16, err := utils.NewFloat16(tx.Amount)
 89	if err != nil {
 90		return nil, err
 91	}
 92	var b [31]byte
 93	copy(b[:4], SwapEndianness(sc.Bytes()))
 94	copy(b[4:6], []byte{1, 0, 0, 0}) // LittleEndian representation of uint32(1) for Ethereum
 95	copy(b[6:12], tx.FromIdx.Bytes())
 96	copy(b[12:18], tx.ToIdx.Bytes())
 97	copy(b[18:20], amountFloat16.Bytes())
 98	copy(b[20:24], tx.TokenID.Bytes())
 99	nonceBytes, err := tx.Nonce.Bytes()
100	if err != nil {
101		return nil, err
102	}
103	copy(b[24:29], nonceBytes[:])
104	b[29] = byte(tx.Fee)
105	toBjjSign := byte(0)
106	if babyjub.PointCoordSign(tx.ToBJJ.X) {
107		toBjjSign = byte(1)
108	}
109	b[30] = toBjjSign
110	bi := new(big.Int).SetBytes(SwapEndianness(b[:]))
111
112	return bi, nil
113}
114
115// TxCompressedDataV2 spec:
116// [ 48 bits ] fromIdx // 6 bytes: [0:6]
117// [ 48 bits ] toIdx // 6 bytes: [6:12]
118// [ 16 bits ] amountFloat16 // 2 bytes: [12:14]
119// [ 32 bits ] tokenID // 4 bytes: [14:18]
120// [ 40 bits ] nonce // 5 bytes: [18:23]
121// [ 8 bits  ] userFee // 1 byte: [23:24]
122// [ 1 bits  ] toBjjSign // 1 byte: [24:25]
123// Total bits compressed data:  193 bits // 25 bytes in *big.Int representation
124func (tx *PoolL2Tx) TxCompressedDataV2() (*big.Int, error) {
125	amountFloat16, err := utils.NewFloat16(tx.Amount)
126	if err != nil {
127		return nil, err
128	}
129	var b [25]byte
130	copy(b[0:6], tx.FromIdx.Bytes())
131	copy(b[6:12], tx.ToIdx.Bytes())
132	copy(b[12:14], amountFloat16.Bytes())
133	copy(b[14:18], tx.TokenID.Bytes())
134	nonceBytes, err := tx.Nonce.Bytes()
135	if err != nil {
136		return nil, err
137	}
138	copy(b[18:23], nonceBytes[:])
139	b[23] = byte(tx.Fee)
140	toBjjSign := byte(0)
141	if babyjub.PointCoordSign(tx.ToBJJ.X) {
142		toBjjSign = byte(1)
143	}
144	b[24] = toBjjSign
145
146	bi := new(big.Int).SetBytes(SwapEndianness(b[:]))
147	return bi, nil
148}
149
150// HashToSign returns the computed Poseidon hash from the *PoolL2Tx that will be signed by the sender.
151func (tx *PoolL2Tx) HashToSign() (*big.Int, error) {
152	toCompressedData, err := tx.TxCompressedData()
153	if err != nil {
154		return nil, err
155	}
156	toEthAddr := EthAddrToBigInt(tx.ToEthAddr)
157	toBjjAy := tx.ToBJJ.Y
158	rqTxCompressedDataV2, err := tx.TxCompressedDataV2()
159	if err != nil {
160		return nil, err
161	}
162
163	return poseidon.Hash([]*big.Int{toCompressedData, toEthAddr, toBjjAy, rqTxCompressedDataV2, EthAddrToBigInt(tx.RqToEthAddr), tx.RqToBJJ.Y})
164}
165
166// VerifySignature returns true if the signature verification is correct for the given PublicKey
167func (tx *PoolL2Tx) VerifySignature(pk *babyjub.PublicKey) bool {
168	h, err := tx.HashToSign()
169	if err != nil {
170		return false
171	}
172	return pk.VerifyPoseidon(h, tx.Signature)
173}
174
175func (tx *PoolL2Tx) L2Tx() *L2Tx {
176	return &L2Tx{
177		TxID:     tx.TxID,
178		BatchNum: tx.BatchNum,
179		FromIdx:  tx.FromIdx,
180		ToIdx:    tx.ToIdx,
181		Amount:   tx.Amount,
182		Fee:      tx.Fee,
183		Nonce:    tx.Nonce,
184		Type:     tx.Type,
185	}
186}
187
188func (tx *PoolL2Tx) Tx() *Tx {
189	return &Tx{
190		TxID:    tx.TxID,
191		FromIdx: tx.FromIdx,
192		ToIdx:   tx.ToIdx,
193		Amount:  tx.Amount,
194		Nonce:   tx.Nonce,
195		Fee:     tx.Fee,
196		Type:    tx.Type,
197	}
198}
199
200func PoolL2TxsToL2Txs(txs []*PoolL2Tx) []*L2Tx {
201	var r []*L2Tx
202	for _, tx := range txs {
203		r = append(r, tx.L2Tx())
204	}
205	return r
206}
207
208// PoolL2TxState is a struct that represents the status of a L2 transaction
209type PoolL2TxState string
210
211const (
212	// PoolL2TxStatePending represents a valid L2Tx that hasn't started the forging process
213	PoolL2TxStatePending PoolL2TxState = "pend"
214	// PoolL2TxStateForging represents a valid L2Tx that has started the forging process
215	PoolL2TxStateForging PoolL2TxState = "fing"
216	// PoolL2TxStateForged represents a L2Tx that has already been forged
217	PoolL2TxStateForged PoolL2TxState = "fged"
218	// PoolL2TxStateInvalid represents a L2Tx that has been invalidated
219	PoolL2TxStateInvalid PoolL2TxState = "invl"
220)