arnaucube
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hermez-node/common/pooll2tx.go
common/pooll2tx.goRaw
  1package common
  2
  3import (
  4	"errors"
  5	"fmt"
  6	"math/big"
  7	"time"
  8
  9	ethCommon "github.com/ethereum/go-ethereum/common"
 10	"github.com/hermeznetwork/tracerr"
 11	"github.com/iden3/go-iden3-crypto/babyjub"
 12	"github.com/iden3/go-iden3-crypto/poseidon"
 13)
 14
 15// PoolL2Tx is a struct that represents a L2Tx sent by an account to the coordinator hat is waiting to be forged
 16type PoolL2Tx struct {
 17	// Stored in DB: mandatory fileds
 18
 19	// TxID (12 bytes) for L2Tx is:
 20	// bytes:  |  1   |    6    |   5   |
 21	// values: | type | FromIdx | Nonce |
 22	TxID      TxID                  `meddler:"tx_id"`
 23	FromIdx   Idx                   `meddler:"from_idx"`
 24	ToIdx     Idx                   `meddler:"to_idx,zeroisnull"`
 25	AuxToIdx  Idx                   `meddler:"-"` // AuxToIdx is only used internally at the StateDB to avoid repeated computation when processing transactions (from Synchronizer, TxSelector, BatchBuilder)
 26	ToEthAddr ethCommon.Address     `meddler:"to_eth_addr,zeroisnull"`
 27	ToBJJ     *babyjub.PublicKey    `meddler:"to_bjj"`
 28	TokenID   TokenID               `meddler:"token_id"`
 29	Amount    *big.Int              `meddler:"amount,bigint"` // TODO: change to float16
 30	Fee       FeeSelector           `meddler:"fee"`
 31	Nonce     Nonce                 `meddler:"nonce"` // effective 40 bits used
 32	State     PoolL2TxState         `meddler:"state"`
 33	Signature babyjub.SignatureComp `meddler:"signature"`         // tx signature
 34	Timestamp time.Time             `meddler:"timestamp,utctime"` // time when added to the tx pool
 35	// Stored in DB: optional fileds, may be uninitialized
 36	RqFromIdx         Idx                `meddler:"rq_from_idx,zeroisnull"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.DepositAmount (deposit)
 37	RqToIdx           Idx                `meddler:"rq_to_idx,zeroisnull"`   // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.DepositAmount (deposit)
 38	RqToEthAddr       ethCommon.Address  `meddler:"rq_to_eth_addr,zeroisnull"`
 39	RqToBJJ           *babyjub.PublicKey `meddler:"rq_to_bjj"` // TODO: stop using json, use scanner/valuer
 40	RqTokenID         TokenID            `meddler:"rq_token_id,zeroisnull"`
 41	RqAmount          *big.Int           `meddler:"rq_amount,bigintnull"` // TODO: change to float16
 42	RqFee             FeeSelector        `meddler:"rq_fee,zeroisnull"`
 43	RqNonce           Nonce              `meddler:"rq_nonce,zeroisnull"` // effective 48 bits used
 44	AbsoluteFee       float64            `meddler:"fee_usd,zeroisnull"`
 45	AbsoluteFeeUpdate time.Time          `meddler:"usd_update,utctimez"`
 46	Type              TxType             `meddler:"tx_type"`
 47	// Extra metadata, may be uninitialized
 48	RqTxCompressedData []byte `meddler:"-"` // 253 bits, optional for atomic txs
 49}
 50
 51// NewPoolL2Tx returns the given L2Tx with the TxId & Type parameters calculated
 52// from the L2Tx values
 53func NewPoolL2Tx(tx *PoolL2Tx) (*PoolL2Tx, error) {
 54	txTypeOld := tx.Type
 55	if err := tx.SetType(); err != nil {
 56		return nil, tracerr.Wrap(err)
 57	}
 58	// If original Type doesn't match the correct one, return error
 59	if txTypeOld != "" && txTypeOld != tx.Type {
 60		return nil, tracerr.Wrap(fmt.Errorf("L2Tx.Type: %s, should be: %s",
 61			tx.Type, txTypeOld))
 62	}
 63
 64	txIDOld := tx.TxID
 65	if err := tx.SetID(); err != nil {
 66		return nil, tracerr.Wrap(err)
 67	}
 68	// If original TxID doesn't match the correct one, return error
 69	if txIDOld != (TxID{}) && txIDOld != tx.TxID {
 70		return tx, tracerr.Wrap(fmt.Errorf("PoolL2Tx.TxID: %s, should be: %s",
 71			tx.TxID.String(), txIDOld.String()))
 72	}
 73
 74	return tx, nil
 75}
 76
 77// SetType sets the type of the transaction
 78func (tx *PoolL2Tx) SetType() error {
 79	if tx.ToIdx >= IdxUserThreshold {
 80		tx.Type = TxTypeTransfer
 81	} else if tx.ToIdx == 1 {
 82		tx.Type = TxTypeExit
 83	} else if tx.ToIdx == 0 {
 84		if tx.ToBJJ != nil && tx.ToEthAddr == FFAddr {
 85			tx.Type = TxTypeTransferToBJJ
 86		} else if tx.ToEthAddr != FFAddr && tx.ToEthAddr != EmptyAddr {
 87			tx.Type = TxTypeTransferToEthAddr
 88		}
 89	} else {
 90		return tracerr.Wrap(errors.New("malformed transaction"))
 91	}
 92	return nil
 93}
 94
 95// SetID sets the ID of the transaction.  Uses (FromIdx, Nonce).
 96func (tx *PoolL2Tx) SetID() error {
 97	tx.TxID[0] = TxIDPrefixL2Tx
 98	fromIdxBytes, err := tx.FromIdx.Bytes()
 99	if err != nil {
100		return tracerr.Wrap(err)
101	}
102	copy(tx.TxID[1:7], fromIdxBytes[:])
103	nonceBytes, err := tx.Nonce.Bytes()
104	if err != nil {
105		return tracerr.Wrap(err)
106	}
107	copy(tx.TxID[7:12], nonceBytes[:])
108	return nil
109}
110
111// TxCompressedData spec:
112// [ 1 bits  ] toBJJSign // 1 byte
113// [ 8 bits  ] userFee // 1 byte
114// [ 40 bits ] nonce // 5 bytes
115// [ 32 bits ] tokenID // 4 bytes
116// [ 16 bits ] amountFloat16 // 2 bytes
117// [ 48 bits ] toIdx // 6 bytes
118// [ 48 bits ] fromIdx // 6 bytes
119// [ 16 bits ] chainId // 2 bytes
120// [ 32 bits ] signatureConstant // 4 bytes
121// Total bits compressed data:  241 bits // 31 bytes in *big.Int representation
122func (tx *PoolL2Tx) TxCompressedData() (*big.Int, error) {
123	amountFloat16, err := NewFloat16(tx.Amount)
124	if err != nil {
125		return nil, tracerr.Wrap(err)
126	}
127	var b [31]byte
128	toBJJSign := byte(0)
129	if tx.ToBJJ != nil && babyjub.PointCoordSign(tx.ToBJJ.X) {
130		toBJJSign = byte(1)
131	}
132	b[0] = toBJJSign
133	b[1] = byte(tx.Fee)
134	nonceBytes, err := tx.Nonce.Bytes()
135	if err != nil {
136		return nil, tracerr.Wrap(err)
137	}
138	copy(b[2:7], nonceBytes[:])
139	copy(b[7:11], tx.TokenID.Bytes())
140	copy(b[11:13], amountFloat16.Bytes())
141	toIdxBytes, err := tx.ToIdx.Bytes()
142	if err != nil {
143		return nil, tracerr.Wrap(err)
144	}
145	copy(b[13:19], toIdxBytes[:])
146	fromIdxBytes, err := tx.FromIdx.Bytes()
147	if err != nil {
148		return nil, tracerr.Wrap(err)
149	}
150	copy(b[19:25], fromIdxBytes[:])
151	copy(b[25:27], []byte{0, 0}) // TODO this will be generated by the ChainID config parameter
152	copy(b[27:31], SignatureConstantBytes[:])
153
154	bi := new(big.Int).SetBytes(b[:])
155	return bi, nil
156}
157
158// TxCompressedDataV2 spec:
159// [ 1 bits  ] toBJJSign // 1 byte
160// [ 8 bits  ] userFee // 1 byte
161// [ 40 bits ] nonce // 5 bytes
162// [ 32 bits ] tokenID // 4 bytes
163// [ 16 bits ] amountFloat16 // 2 bytes
164// [ 48 bits ] toIdx // 6 bytes
165// [ 48 bits ] fromIdx // 6 bytes
166// Total bits compressed data:  193 bits // 25 bytes in *big.Int representation
167func (tx *PoolL2Tx) TxCompressedDataV2() (*big.Int, error) {
168	if tx.Amount == nil {
169		tx.Amount = big.NewInt(0)
170	}
171	amountFloat16, err := NewFloat16(tx.Amount)
172	if err != nil {
173		return nil, tracerr.Wrap(err)
174	}
175	var b [25]byte
176	toBJJSign := byte(0)
177	if tx.ToBJJ != nil && babyjub.PointCoordSign(tx.ToBJJ.X) {
178		toBJJSign = byte(1)
179	}
180	b[0] = toBJJSign
181	b[1] = byte(tx.Fee)
182	nonceBytes, err := tx.Nonce.Bytes()
183	if err != nil {
184		return nil, tracerr.Wrap(err)
185	}
186	copy(b[2:7], nonceBytes[:])
187	copy(b[7:11], tx.TokenID.Bytes())
188	copy(b[11:13], amountFloat16.Bytes())
189	toIdxBytes, err := tx.ToIdx.Bytes()
190	if err != nil {
191		return nil, tracerr.Wrap(err)
192	}
193	copy(b[13:19], toIdxBytes[:])
194	fromIdxBytes, err := tx.FromIdx.Bytes()
195	if err != nil {
196		return nil, tracerr.Wrap(err)
197	}
198	copy(b[19:25], fromIdxBytes[:])
199
200	bi := new(big.Int).SetBytes(b[:])
201	return bi, nil
202}
203
204// RqTxCompressedDataV2 is like the TxCompressedDataV2 but using the 'Rq'
205// parameters. In a future iteration of the hermez-node, the 'Rq' parameters
206// can be inside a struct, which contains the 'Rq' transaction grouped inside,
207// so then computing the 'RqTxCompressedDataV2' would be just calling
208// 'tx.Rq.TxCompressedDataV2()'.
209// RqTxCompressedDataV2 spec:
210// [ 1 bits  ] rqToBJJSign // 1 byte
211// [ 8 bits  ] rqUserFee // 1 byte
212// [ 40 bits ] rqNonce // 5 bytes
213// [ 32 bits ] rqTokenID // 4 bytes
214// [ 16 bits ] rqAmountFloat16 // 2 bytes
215// [ 48 bits ] rqToIdx // 6 bytes
216// [ 48 bits ] rqFromIdx // 6 bytes
217// Total bits compressed data:  193 bits // 25 bytes in *big.Int representation
218func (tx *PoolL2Tx) RqTxCompressedDataV2() (*big.Int, error) {
219	if tx.RqAmount == nil {
220		tx.RqAmount = big.NewInt(0)
221	}
222	amountFloat16, err := NewFloat16(tx.RqAmount)
223	if err != nil {
224		return nil, tracerr.Wrap(err)
225	}
226	var b [25]byte
227	toBJJSign := byte(0)
228	if tx.RqToBJJ != nil && babyjub.PointCoordSign(tx.RqToBJJ.X) {
229		toBJJSign = byte(1)
230	}
231	b[0] = toBJJSign
232	b[1] = byte(tx.RqFee)
233	nonceBytes, err := tx.RqNonce.Bytes()
234	if err != nil {
235		return nil, tracerr.Wrap(err)
236	}
237	copy(b[2:7], nonceBytes[:])
238	copy(b[7:11], tx.RqTokenID.Bytes())
239	copy(b[11:13], amountFloat16.Bytes())
240	toIdxBytes, err := tx.RqToIdx.Bytes()
241	if err != nil {
242		return nil, tracerr.Wrap(err)
243	}
244	copy(b[13:19], toIdxBytes[:])
245	fromIdxBytes, err := tx.RqFromIdx.Bytes()
246	if err != nil {
247		return nil, tracerr.Wrap(err)
248	}
249	copy(b[19:25], fromIdxBytes[:])
250
251	bi := new(big.Int).SetBytes(b[:])
252	return bi, nil
253}
254
255// HashToSign returns the computed Poseidon hash from the *PoolL2Tx that will be signed by the sender.
256func (tx *PoolL2Tx) HashToSign() (*big.Int, error) {
257	toCompressedData, err := tx.TxCompressedData()
258	if err != nil {
259		return nil, tracerr.Wrap(err)
260	}
261	toEthAddr := EthAddrToBigInt(tx.ToEthAddr)
262	rqToEthAddr := EthAddrToBigInt(tx.RqToEthAddr)
263	toBJJY := big.NewInt(0)
264	if tx.ToBJJ != nil {
265		toBJJY = tx.ToBJJ.Y
266	}
267	rqTxCompressedDataV2, err := tx.RqTxCompressedDataV2()
268	if err != nil {
269		return nil, tracerr.Wrap(err)
270	}
271	rqToBJJY := big.NewInt(0)
272	if tx.RqToBJJ != nil {
273		rqToBJJY = tx.RqToBJJ.Y
274	}
275
276	return poseidon.Hash([]*big.Int{toCompressedData, toEthAddr, toBJJY, rqTxCompressedDataV2, rqToEthAddr, rqToBJJY})
277}
278
279// VerifySignature returns true if the signature verification is correct for the given PublicKey
280func (tx *PoolL2Tx) VerifySignature(pk *babyjub.PublicKey) bool {
281	h, err := tx.HashToSign()
282	if err != nil {
283		return false
284	}
285	s, err := tx.Signature.Decompress()
286	if err != nil {
287		return false
288	}
289	return pk.VerifyPoseidon(h, s)
290}
291
292// L2Tx returns a *L2Tx from the PoolL2Tx
293func (tx PoolL2Tx) L2Tx() L2Tx {
294	return L2Tx{
295		TxID:    tx.TxID,
296		FromIdx: tx.FromIdx,
297		ToIdx:   tx.ToIdx,
298		Amount:  tx.Amount,
299		Fee:     tx.Fee,
300		Nonce:   tx.Nonce,
301		Type:    tx.Type,
302	}
303}
304
305// Tx returns a *Tx from the PoolL2Tx
306func (tx PoolL2Tx) Tx() Tx {
307	return Tx{
308		TxID:    tx.TxID,
309		FromIdx: tx.FromIdx,
310		ToIdx:   tx.ToIdx,
311		Amount:  tx.Amount,
312		TokenID: tx.TokenID,
313		Nonce:   &tx.Nonce,
314		Fee:     &tx.Fee,
315		Type:    tx.Type,
316	}
317}
318
319// PoolL2TxsToL2Txs returns an array of []L2Tx from an array of []PoolL2Tx
320func PoolL2TxsToL2Txs(txs []PoolL2Tx) ([]L2Tx, error) {
321	l2Txs := make([]L2Tx, len(txs))
322	for i, poolTx := range txs {
323		l2Txs[i] = poolTx.L2Tx()
324	}
325	return l2Txs, nil
326}
327
328// PoolL2TxState is a struct that represents the status of a L2 transaction
329type PoolL2TxState string
330
331const (
332	// PoolL2TxStatePending represents a valid L2Tx that hasn't started the forging process
333	PoolL2TxStatePending PoolL2TxState = "pend"
334	// PoolL2TxStateForging represents a valid L2Tx that has started the forging process
335	PoolL2TxStateForging PoolL2TxState = "fing"
336	// PoolL2TxStateForged represents a L2Tx that has already been forged
337	PoolL2TxStateForged PoolL2TxState = "fged"
338	// PoolL2TxStateInvalid represents a L2Tx that has been invalidated
339	PoolL2TxStateInvalid PoolL2TxState = "invl"
340)