1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
// See the file LICENSE for licensing terms.
package evm
import (
//"crypto/ecdsa"
"errors"
"fmt"
"github.com/ava-labs/gecko/database"
"github.com/ava-labs/gecko/ids"
"github.com/ava-labs/gecko/snow"
avacrypto "github.com/ava-labs/gecko/utils/crypto"
"github.com/ava-labs/gecko/utils/math"
"github.com/ava-labs/gecko/vms/components/avax"
//"github.com/ava-labs/gecko/vms/components/verify"
"github.com/ava-labs/gecko/vms/secp256k1fx"
"github.com/ava-labs/go-ethereum/common"
//"github.com/ava-labs/go-ethereum/crypto"
)
var (
errAssetIDMismatch = errors.New("asset IDs in the input don't match the utxo")
errWrongNumberOfCredentials = errors.New("should have the same number of credentials as inputs")
errNoInputs = errors.New("tx has no inputs")
errNoImportInputs = errors.New("tx has no imported inputs")
errInputsNotSortedUnique = errors.New("inputs not sorted and unique")
errPublicKeySignatureMismatch = errors.New("signature doesn't match public key")
errUnknownAsset = errors.New("unknown asset ID")
errNoFunds = errors.New("no spendable funds were found")
errWrongChainID = errors.New("tx has wrong chain ID")
)
// UnsignedImportTx is an unsigned ImportTx
type UnsignedImportTx struct {
BaseTx `serialize:"true"`
// Which chain to consume the funds from
SourceChain ids.ID `serialize:"true" json:"sourceChain"`
// Inputs that consume UTXOs produced on the chain
ImportedInputs []*avax.TransferableInput `serialize:"true" json:"importedInputs"`
}
// InputUTXOs returns the UTXOIDs of the imported funds
func (tx *UnsignedImportTx) InputUTXOs() ids.Set {
set := ids.Set{}
for _, in := range tx.ImportedInputs {
set.Add(in.InputID())
}
return set
}
// Verify this transaction is well-formed
func (tx *UnsignedImportTx) Verify(
avmID ids.ID,
ctx *snow.Context,
feeAmount uint64,
feeAssetID ids.ID,
) error {
switch {
case tx == nil:
return errNilTx
case tx.syntacticallyVerified: // already passed syntactic verification
return nil
case tx.SourceChain.IsZero():
return errWrongChainID
case !tx.SourceChain.Equals(avmID):
// TODO: remove this check if we allow for P->C swaps
return errWrongChainID
case len(tx.ImportedInputs) == 0:
return errNoImportInputs
}
if err := tx.BaseTx.Verify(ctx); err != nil {
return err
}
for _, in := range tx.ImportedInputs {
if err := in.Verify(); err != nil {
return err
}
}
if !avax.IsSortedAndUniqueTransferableInputs(tx.ImportedInputs) {
return errInputsNotSortedUnique
}
tx.syntacticallyVerified = true
return nil
}
// SemanticVerify this transaction is valid.
func (tx *UnsignedImportTx) SemanticVerify(
vm *VM,
stx *Tx,
) TxError {
if err := tx.Verify(vm.avm, vm.ctx, vm.txFee, vm.avaxAssetID); err != nil {
return permError{err}
}
// TODO: verify using avax.VerifyTx(vm.txFee, vm.avaxAssetID, tx.Ins, outs)
// TODO: verify UTXO inputs via gRPC (with creds)
return nil
}
// Accept this transaction and spend imported inputs
// We spend imported UTXOs here rather than in semanticVerify because
// we don't want to remove an imported UTXO in semanticVerify
// only to have the transaction not be Accepted. This would be inconsistent.
// Recall that imported UTXOs are not kept in a versionDB.
func (tx *UnsignedImportTx) Accept(batch database.Batch) error {
// TODO: finish this function via gRPC
return nil
}
// Create a new transaction
func (vm *VM) newImportTx(
chainID ids.ID, // chain to import from
to common.Address, // Address of recipient
keys []*avacrypto.PrivateKeySECP256K1R, // Keys to import the funds
) (*Tx, error) {
if !vm.avm.Equals(chainID) {
return nil, errWrongChainID
}
kc := secp256k1fx.NewKeychain()
for _, key := range keys {
kc.Add(key)
}
atomicUTXOs, _, _, err := vm.GetAtomicUTXOs(chainID, kc.Addresses(), ids.ShortEmpty, ids.Empty, -1)
if err != nil {
return nil, fmt.Errorf("problem retrieving atomic UTXOs: %w", err)
}
importedInputs := []*avax.TransferableInput{}
signers := [][]*avacrypto.PrivateKeySECP256K1R{}
importedAmount := uint64(0)
now := vm.clock.Unix()
for _, utxo := range atomicUTXOs {
if !utxo.AssetID().Equals(vm.avaxAssetID) {
continue
}
inputIntf, utxoSigners, err := kc.Spend(utxo.Out, now)
if err != nil {
continue
}
input, ok := inputIntf.(avax.TransferableIn)
if !ok {
continue
}
importedAmount, err = math.Add64(importedAmount, input.Amount())
if err != nil {
return nil, err
}
importedInputs = append(importedInputs, &avax.TransferableInput{
UTXOID: utxo.UTXOID,
Asset: utxo.Asset,
In: input,
})
signers = append(signers, utxoSigners)
}
avax.SortTransferableInputsWithSigners(importedInputs, signers)
if importedAmount == 0 {
return nil, errNoFunds // No imported UTXOs were spendable
}
ins := []*avax.TransferableInput{}
outs := []EVMOutput{}
if importedAmount < vm.txFee { // imported amount goes toward paying tx fee
// TODO: spend EVM balance to compensate vm.txFee-importedAmount
} else if importedAmount > vm.txFee {
outs = append(outs, EVMOutput{
Address: to,
Amount: importedAmount - vm.txFee,
})
}
// Create the transaction
utx := &UnsignedImportTx{
BaseTx: BaseTx{
NetworkID: vm.ctx.NetworkID,
BlockchainID: vm.ctx.ChainID,
Outs: outs,
Ins: ins,
},
SourceChain: chainID,
ImportedInputs: importedInputs,
}
tx := &Tx{UnsignedTx: utx}
if err := tx.Sign(vm.codec, signers); err != nil {
return nil, err
}
return tx, utx.Verify(vm.avm, vm.ctx, vm.txFee, vm.avaxAssetID)
}
|