hermez-node/common/l1tx.go
common/l1tx.goRaw
1package common
2
3import (
4 "encoding/binary"
5 "fmt"
6 "math/big"
7
8 ethCommon "github.com/ethereum/go-ethereum/common"
9 "github.com/ethereum/go-ethereum/crypto"
10 "github.com/hermeznetwork/tracerr"
11 "github.com/iden3/go-iden3-crypto/babyjub"
12)
13
14const (
15 // L1UserTxBytesLen is the length of the byte array that represents the L1Tx
16 L1UserTxBytesLen = 72
17 // L1CoordinatorTxBytesLen is the length of the byte array that represents the L1CoordinatorTx
18 L1CoordinatorTxBytesLen = 101
19)
20
21// L1Tx is a struct that represents a L1 tx
22type L1Tx struct {
23 // Stored in DB: mandatory fileds
24
25 // TxID (12 bytes) for L1Tx is:
26 // bytes: | 1 | 8 | 2 | 1 |
27 // values: | type | ToForgeL1TxsNum | Position | 0 (padding) |
28 // where type:
29 // - L1UserTx: 0
30 // - L1CoordinatorTx: 1
31 TxID TxID `meddler:"id"`
32 ToForgeL1TxsNum *int64 `meddler:"to_forge_l1_txs_num"` // toForgeL1TxsNum in which the tx was forged / will be forged
33 Position int `meddler:"position"`
34 UserOrigin bool `meddler:"user_origin"` // true if the tx was originated by a user, false if it was aoriginated by a coordinator. Note that this differ from the spec for implementation simplification purpposes
35 FromIdx Idx `meddler:"from_idx,zeroisnull"` // FromIdx is used by L1Tx/Deposit to indicate the Idx receiver of the L1Tx.DepositAmount (deposit)
36 EffectiveFromIdx Idx `meddler:"effective_from_idx,zeroisnull"`
37 FromEthAddr ethCommon.Address `meddler:"from_eth_addr,zeroisnull"`
38 FromBJJ babyjub.PublicKeyComp `meddler:"from_bjj,zeroisnull"`
39 ToIdx Idx `meddler:"to_idx"` // ToIdx is ignored in L1Tx/Deposit, but used in the L1Tx/DepositAndTransfer
40 TokenID TokenID `meddler:"token_id"`
41 Amount *big.Int `meddler:"amount,bigint"`
42 // EffectiveAmount only applies to L1UserTx.
43 EffectiveAmount *big.Int `meddler:"effective_amount,bigintnull"`
44 DepositAmount *big.Int `meddler:"deposit_amount,bigint"`
45 // EffectiveDepositAmount only applies to L1UserTx.
46 EffectiveDepositAmount *big.Int `meddler:"effective_deposit_amount,bigintnull"`
47 EthBlockNum int64 `meddler:"eth_block_num"` // Ethereum Block Number in which this L1Tx was added to the queue
48 Type TxType `meddler:"type"`
49 BatchNum *BatchNum `meddler:"batch_num"`
50}
51
52// NewL1Tx returns the given L1Tx with the TxId & Type parameters calculated
53// from the L1Tx values
54func NewL1Tx(tx *L1Tx) (*L1Tx, error) {
55 txTypeOld := tx.Type
56 if err := tx.SetType(); err != nil {
57 return nil, tracerr.Wrap(err)
58 }
59 // If original Type doesn't match the correct one, return error
60 if txTypeOld != "" && txTypeOld != tx.Type {
61 return nil, tracerr.Wrap(fmt.Errorf("L1Tx.Type: %s, should be: %s",
62 tx.Type, txTypeOld))
63 }
64
65 txIDOld := tx.TxID
66 if err := tx.SetID(); err != nil {
67 return nil, tracerr.Wrap(err)
68 }
69 // If original TxID doesn't match the correct one, return error
70 if txIDOld != (TxID{}) && txIDOld != tx.TxID {
71 return tx, tracerr.Wrap(fmt.Errorf("L1Tx.TxID: %s, should be: %s",
72 tx.TxID.String(), txIDOld.String()))
73 }
74
75 return tx, nil
76}
77
78// SetType sets the type of the transaction
79func (tx *L1Tx) SetType() error {
80 if tx.FromIdx == 0 {
81 if tx.ToIdx == Idx(0) {
82 tx.Type = TxTypeCreateAccountDeposit
83 } else if tx.ToIdx >= IdxUserThreshold {
84 tx.Type = TxTypeCreateAccountDepositTransfer
85 } else {
86 return tracerr.Wrap(fmt.Errorf(
87 "Can not determine type of L1Tx, invalid ToIdx value: %d", tx.ToIdx))
88 }
89 } else if tx.FromIdx >= IdxUserThreshold {
90 if tx.ToIdx == Idx(0) {
91 tx.Type = TxTypeDeposit
92 } else if tx.ToIdx == Idx(1) {
93 tx.Type = TxTypeForceExit
94 } else if tx.ToIdx >= IdxUserThreshold {
95 if tx.DepositAmount.Int64() == int64(0) {
96 tx.Type = TxTypeForceTransfer
97 } else {
98 tx.Type = TxTypeDepositTransfer
99 }
100 } else {
101 return tracerr.Wrap(fmt.Errorf(
102 "Can not determine type of L1Tx, invalid ToIdx value: %d", tx.ToIdx))
103 }
104 } else {
105 return tracerr.Wrap(fmt.Errorf(
106 "Can not determine type of L1Tx, invalid FromIdx value: %d", tx.FromIdx))
107 }
108 return nil
109}
110
111// SetID sets the ID of the transaction. For L1UserTx uses (ToForgeL1TxsNum,
112// Position), for L1CoordinatorTx uses (BatchNum, Position).
113func (tx *L1Tx) SetID() error {
114 if tx.UserOrigin {
115 if tx.ToForgeL1TxsNum == nil {
116 return tracerr.Wrap(fmt.Errorf("L1Tx.UserOrigin == true && L1Tx.ToForgeL1TxsNum == nil"))
117 }
118 tx.TxID[0] = TxIDPrefixL1UserTx
119 var toForgeL1TxsNumBytes [8]byte
120 binary.BigEndian.PutUint64(toForgeL1TxsNumBytes[:], uint64(*tx.ToForgeL1TxsNum))
121 copy(tx.TxID[1:9], toForgeL1TxsNumBytes[:])
122 } else {
123 if tx.BatchNum == nil {
124 return tracerr.Wrap(fmt.Errorf("L1Tx.UserOrigin == false && L1Tx.BatchNum == nil"))
125 }
126 tx.TxID[0] = TxIDPrefixL1CoordTx
127 var batchNumBytes [8]byte
128 binary.BigEndian.PutUint64(batchNumBytes[:], uint64(*tx.BatchNum))
129 copy(tx.TxID[1:9], batchNumBytes[:])
130 }
131 var positionBytes [2]byte
132 binary.BigEndian.PutUint16(positionBytes[:], uint16(tx.Position))
133 copy(tx.TxID[9:11], positionBytes[:])
134
135 return nil
136}
137
138// Tx returns a *Tx from the L1Tx
139func (tx L1Tx) Tx() Tx {
140 f := new(big.Float).SetInt(tx.EffectiveAmount)
141 amountFloat, _ := f.Float64()
142 userOrigin := new(bool)
143 *userOrigin = tx.UserOrigin
144 genericTx := Tx{
145 IsL1: true,
146 TxID: tx.TxID,
147 Type: tx.Type,
148 Position: tx.Position,
149 FromIdx: tx.FromIdx,
150 ToIdx: tx.ToIdx,
151 Amount: tx.EffectiveAmount,
152 AmountFloat: amountFloat,
153 TokenID: tx.TokenID,
154 ToForgeL1TxsNum: tx.ToForgeL1TxsNum,
155 UserOrigin: userOrigin,
156 FromEthAddr: tx.FromEthAddr,
157 FromBJJ: tx.FromBJJ,
158 DepositAmount: tx.EffectiveDepositAmount,
159 EthBlockNum: tx.EthBlockNum,
160 }
161 if tx.DepositAmount != nil {
162 lf := new(big.Float).SetInt(tx.DepositAmount)
163 depositAmountFloat, _ := lf.Float64()
164 genericTx.DepositAmountFloat = &depositAmountFloat
165 }
166 return genericTx
167}
168
169// TxCompressedData spec:
170// [ 1 bits ] empty (toBJJSign) // 1 byte
171// [ 8 bits ] empty (userFee) // 1 byte
172// [ 40 bits ] empty (nonce) // 5 bytes
173// [ 32 bits ] tokenID // 4 bytes
174// [ 16 bits ] amountFloat16 // 2 bytes
175// [ 48 bits ] toIdx // 6 bytes
176// [ 48 bits ] fromIdx // 6 bytes
177// [ 16 bits ] chainId // 2 bytes
178// [ 32 bits ] empty (signatureConstant) // 4 bytes
179// Total bits compressed data: 241 bits // 31 bytes in *big.Int representation
180func (tx L1Tx) TxCompressedData(chainID uint16) (*big.Int, error) {
181 amountFloat16, err := NewFloat16(tx.Amount)
182 if err != nil {
183 return nil, tracerr.Wrap(err)
184 }
185
186 var b [31]byte
187 // b[0:7] empty: no ToBJJSign, no fee, no nonce
188 copy(b[7:11], tx.TokenID.Bytes())
189 copy(b[11:13], amountFloat16.Bytes())
190 toIdxBytes, err := tx.ToIdx.Bytes()
191 if err != nil {
192 return nil, tracerr.Wrap(err)
193 }
194 copy(b[13:19], toIdxBytes[:])
195 fromIdxBytes, err := tx.FromIdx.Bytes()
196 if err != nil {
197 return nil, tracerr.Wrap(err)
198 }
199 copy(b[19:25], fromIdxBytes[:])
200 binary.BigEndian.PutUint16(b[25:27], chainID)
201 copy(b[27:31], SignatureConstantBytes[:])
202
203 bi := new(big.Int).SetBytes(b[:])
204 return bi, nil
205}
206
207// BytesDataAvailability encodes a L1Tx into []byte for the Data Availability
208func (tx *L1Tx) BytesDataAvailability(nLevels uint32) ([]byte, error) {
209 idxLen := nLevels / 8 //nolint:gomnd
210
211 b := make([]byte, ((nLevels*2)+16+8)/8) //nolint:gomnd
212
213 fromIdxBytes, err := tx.FromIdx.Bytes()
214 if err != nil {
215 return nil, tracerr.Wrap(err)
216 }
217 copy(b[0:idxLen], fromIdxBytes[6-idxLen:])
218 toIdxBytes, err := tx.ToIdx.Bytes()
219 if err != nil {
220 return nil, tracerr.Wrap(err)
221 }
222 copy(b[idxLen:idxLen*2], toIdxBytes[6-idxLen:])
223
224 if tx.EffectiveAmount != nil {
225 amountFloat16, err := NewFloat16(tx.EffectiveAmount)
226 if err != nil {
227 return nil, tracerr.Wrap(err)
228 }
229 copy(b[idxLen*2:idxLen*2+2], amountFloat16.Bytes())
230 }
231 // fee = 0 (as is L1Tx) b[10:11]
232 return b[:], nil
233}
234
235// L1TxFromDataAvailability decodes a L1Tx from []byte (Data Availability)
236func L1TxFromDataAvailability(b []byte, nLevels uint32) (*L1Tx, error) {
237 idxLen := nLevels / 8 //nolint:gomnd
238
239 fromIdxBytes := b[0:idxLen]
240 toIdxBytes := b[idxLen : idxLen*2]
241 amountBytes := b[idxLen*2 : idxLen*2+2]
242
243 l1tx := L1Tx{}
244 fromIdx, err := IdxFromBytes(ethCommon.LeftPadBytes(fromIdxBytes, 6))
245 if err != nil {
246 return nil, tracerr.Wrap(err)
247 }
248 l1tx.FromIdx = fromIdx
249 toIdx, err := IdxFromBytes(ethCommon.LeftPadBytes(toIdxBytes, 6))
250 if err != nil {
251 return nil, tracerr.Wrap(err)
252 }
253 l1tx.ToIdx = toIdx
254 l1tx.EffectiveAmount = Float16FromBytes(amountBytes).BigInt()
255 return &l1tx, nil
256}
257
258// BytesGeneric returns the generic representation of a L1Tx. This method is
259// used to compute the []byte representation of a L1UserTx, and also to compute
260// the L1TxData for the ZKInputs (at the HashGlobalInputs), using this method
261// for L1CoordinatorTxs & L1UserTxs (for the ZKInputs case).
262func (tx *L1Tx) BytesGeneric() ([]byte, error) {
263 var b [L1UserTxBytesLen]byte
264 copy(b[0:20], tx.FromEthAddr.Bytes())
265 if tx.FromBJJ != EmptyBJJComp {
266 pkCompL := tx.FromBJJ
267 pkCompB := SwapEndianness(pkCompL[:])
268 copy(b[20:52], pkCompB[:])
269 }
270 fromIdxBytes, err := tx.FromIdx.Bytes()
271 if err != nil {
272 return nil, tracerr.Wrap(err)
273 }
274 copy(b[52:58], fromIdxBytes[:])
275 depositAmountFloat16, err := NewFloat16(tx.DepositAmount)
276 if err != nil {
277 return nil, tracerr.Wrap(err)
278 }
279 copy(b[58:60], depositAmountFloat16.Bytes())
280 amountFloat16, err := NewFloat16(tx.Amount)
281 if err != nil {
282 return nil, tracerr.Wrap(err)
283 }
284 copy(b[60:62], amountFloat16.Bytes())
285 copy(b[62:66], tx.TokenID.Bytes())
286 toIdxBytes, err := tx.ToIdx.Bytes()
287 if err != nil {
288 return nil, tracerr.Wrap(err)
289 }
290 copy(b[66:72], toIdxBytes[:])
291 return b[:], nil
292}
293
294// BytesUser encodes a L1UserTx into []byte
295func (tx *L1Tx) BytesUser() ([]byte, error) {
296 if !tx.UserOrigin {
297 return nil, tracerr.Wrap(fmt.Errorf("Can not calculate BytesUser() for a L1CoordinatorTx"))
298 }
299 return tx.BytesGeneric()
300}
301
302// BytesCoordinatorTx encodes a L1CoordinatorTx into []byte
303func (tx *L1Tx) BytesCoordinatorTx(compressedSignatureBytes []byte) ([]byte, error) {
304 if tx.UserOrigin {
305 return nil, tracerr.Wrap(fmt.Errorf("Can not calculate BytesCoordinatorTx() for a L1UserTx"))
306 }
307 var b [L1CoordinatorTxBytesLen]byte
308 v := compressedSignatureBytes[64]
309 s := compressedSignatureBytes[32:64]
310 r := compressedSignatureBytes[0:32]
311 b[0] = v
312 copy(b[1:33], s)
313 copy(b[33:65], r)
314 pkCompL := tx.FromBJJ
315 pkCompB := SwapEndianness(pkCompL[:])
316 copy(b[65:97], pkCompB[:])
317 copy(b[97:101], tx.TokenID.Bytes())
318 return b[:], nil
319}
320
321// L1UserTxFromBytes decodes a L1Tx from []byte
322func L1UserTxFromBytes(b []byte) (*L1Tx, error) {
323 if len(b) != L1UserTxBytesLen {
324 return nil, tracerr.Wrap(fmt.Errorf("Can not parse L1Tx bytes, expected length %d, current: %d", 68, len(b)))
325 }
326
327 tx := &L1Tx{
328 UserOrigin: true,
329 }
330 var err error
331 tx.FromEthAddr = ethCommon.BytesToAddress(b[0:20])
332
333 pkCompB := b[20:52]
334 pkCompL := SwapEndianness(pkCompB)
335 copy(tx.FromBJJ[:], pkCompL)
336 fromIdx, err := IdxFromBytes(b[52:58])
337 if err != nil {
338 return nil, tracerr.Wrap(err)
339 }
340 tx.FromIdx = fromIdx
341 tx.DepositAmount = Float16FromBytes(b[58:60]).BigInt()
342 tx.Amount = Float16FromBytes(b[60:62]).BigInt()
343 tx.TokenID, err = TokenIDFromBytes(b[62:66])
344 if err != nil {
345 return nil, tracerr.Wrap(err)
346 }
347 tx.ToIdx, err = IdxFromBytes(b[66:72])
348 if err != nil {
349 return nil, tracerr.Wrap(err)
350 }
351
352 return tx, nil
353}
354
355func signHash(data []byte) []byte {
356 msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), data)
357 return crypto.Keccak256([]byte(msg))
358}
359
360// L1CoordinatorTxFromBytes decodes a L1Tx from []byte
361func L1CoordinatorTxFromBytes(b []byte, chainID *big.Int, hermezAddress ethCommon.Address) (*L1Tx, error) {
362 if len(b) != L1CoordinatorTxBytesLen {
363 return nil, tracerr.Wrap(fmt.Errorf("Can not parse L1CoordinatorTx bytes, expected length %d, current: %d", 101, len(b)))
364 }
365
366 bytesMessage := []byte("I authorize this babyjubjub key for hermez rollup account creation")
367
368 tx := &L1Tx{
369 UserOrigin: false,
370 }
371 var err error
372 v := b[0]
373 s := b[1:33]
374 r := b[33:65]
375 pkCompB := b[65:97]
376 pkCompL := SwapEndianness(pkCompB)
377 copy(tx.FromBJJ[:], pkCompL)
378 tx.TokenID, err = TokenIDFromBytes(b[97:101])
379 if err != nil {
380 return nil, tracerr.Wrap(err)
381 }
382 tx.Amount = big.NewInt(0)
383 tx.DepositAmount = big.NewInt(0)
384 if int(v) > 0 {
385 // L1CoordinatorTX ETH
386 // Ethereum adds 27 to v
387 v = b[0] - byte(27) //nolint:gomnd
388 chainIDBytes := ethCommon.LeftPadBytes(chainID.Bytes(), 2)
389 var data []byte
390 data = append(data, bytesMessage...)
391 data = append(data, pkCompB...)
392 data = append(data, chainIDBytes[:]...)
393 data = append(data, hermezAddress.Bytes()...)
394 var signature []byte
395 signature = append(signature, r[:]...)
396 signature = append(signature, s[:]...)
397 signature = append(signature, v)
398 hash := signHash(data)
399 pubKeyBytes, err := crypto.Ecrecover(hash, signature)
400 if err != nil {
401 return nil, tracerr.Wrap(err)
402 }
403 pubKey, err := crypto.UnmarshalPubkey(pubKeyBytes)
404 if err != nil {
405 return nil, tracerr.Wrap(err)
406 }
407 tx.FromEthAddr = crypto.PubkeyToAddress(*pubKey)
408 } else {
409 // L1Coordinator Babyjub
410 tx.FromEthAddr = RollupConstEthAddressInternalOnly
411 }
412 return tx, nil
413}