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feat: RIP-7212 precompile
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‎libevm/precompiles/p256verify/p256verify.go‎

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// Copyright 2025 the libevm authors.
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//
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// The libevm additions to go-ethereum are free software: you can redistribute
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// them and/or modify them under the terms of the GNU Lesser General Public License
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// as published by the Free Software Foundation, either version 3 of the License,
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// or (at your option) any later version.
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//
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// The libevm additions are distributed in the hope that they will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
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// General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see
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// <http://www.gnu.org/licenses/>.
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// Package p256verify implements an EVM precompile to verify P256 ECDSA
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// signatures, as described in RIP-7212.
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package p256verify
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import (
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"crypto/ecdsa"
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"crypto/elliptic"
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"crypto/rand"
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"math/big"
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)
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// Precompile implements ECDSA verification on the P256 curve, as defined by
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// [RIP-7212].
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//
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// [RIP-7212]: https://github.com/ethereum/RIPs/blob/1f55794f65caa4c4bb2b8d9bda7d713b8c734157/RIPS/rip-7212.md
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type Precompile struct{}
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// RequiredGas always returns 3450.
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func (Precompile) RequiredGas([]byte) uint64 { return 3450 }
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const inputLen = 160
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type input [inputLen]byte
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// Run parses and verifies the signature. On success it returns a 32-byte
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// big-endian representation of the number 1, otherwise it returns an empty
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// slice. The returned error is always nil.
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func (Precompile) Run(sig []byte) ([]byte, error) {
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if len(sig) != inputLen || !(*input)(sig).verify() {
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return nil, nil
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}
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return []byte{31: 1}, nil
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}
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func (in *input) verify() bool {
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key, ok := in.pubkey()
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if !ok {
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return false
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}
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return ecdsa.Verify(key, in.word(0), in.bigWord(1), in.bigWord(2))
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}
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func (in *input) pubkey() (*ecdsa.PublicKey, bool) {
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x := in.bigWord(3)
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y := in.bigWord(4)
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if x.Sign() == 0 && y.Sign() == 0 {
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return nil, false
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}
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curve := elliptic.P256()
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if !curve.IsOnCurve(x, y) {
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return nil, false
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}
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return &ecdsa.PublicKey{
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Curve: curve,
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X: x,
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Y: y,
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}, true
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}
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func (in *input) word(index int) []byte {
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s := index * 32
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return in[s : s+32]
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}
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func (in *input) bigWord(index int) *big.Int {
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return new(big.Int).SetBytes(in.word(index))
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}
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// Sign signs `hash` with the private key, returning a byte slice compatible
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// with [Precompile.Run]. It uses [rand.Reader] as the first argument to
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// [ecdsa.Sign].
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func Sign(priv *ecdsa.PrivateKey, hash [32]byte) ([]byte, error) {
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r, s, err := ecdsa.Sign(rand.Reader, priv, hash[:])
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if err != nil {
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return nil, err
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}
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var in input
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copy(in.word(0), hash[:])
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r.FillBytes(in.word(1))
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s.FillBytes(in.word(2))
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priv.X.FillBytes(in.word(3))
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priv.Y.FillBytes(in.word(4))
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return in[:], nil
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}

‎libevm/precompiles/p256verify/p256verify_test.go‎

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// Copyright 2025 the libevm authors.
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//
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// The libevm additions to go-ethereum are free software: you can redistribute
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// them and/or modify them under the terms of the GNU Lesser General Public License
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// as published by the Free Software Foundation, either version 3 of the License,
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// or (at your option) any later version.
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//
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// The libevm additions are distributed in the hope that they will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
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// General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see
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// <http://www.gnu.org/licenses/>.
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package p256verify
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import (
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"crypto/ecdsa"
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"crypto/elliptic"
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"crypto/rand"
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"testing"
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"github.com/ava-labs/libevm/common"
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"github.com/ava-labs/libevm/core/vm"
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"github.com/ava-labs/libevm/libevm"
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"github.com/ava-labs/libevm/libevm/ethtest"
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"github.com/ava-labs/libevm/libevm/hookstest"
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"github.com/ava-labs/libevm/params"
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"github.com/holiman/uint256"
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"github.com/stretchr/testify/assert"
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"github.com/stretchr/testify/require"
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)
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// ulerdoganTestCase is the test case from
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// https://github.com/ulerdogan/go-ethereum/blob/cec0b058115282168c5afc5197de3f6b5479dc4a/core/vm/testdata/precompiles/p256Verify.json,
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// copied under LGPL. See the respective commit for copyright and license
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// information.
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const ulerdoganTestCase = `4cee90eb86eaa050036147a12d49004b6b9c72bd725d39d4785011fe190f0b4da73bd4903f0ce3b639bbbf6e8e80d16931ff4bcf5993d58468e8fb19086e8cac36dbcd03009df8c59286b162af3bd7fcc0450c9aa81be5d10d312af6c66b1d604aebd3099c618202fcfe16ae7770b0c49ab5eadf74b754204a3bb6060e44eff37618b065f9832de4ca6ca971a7a1adc826d0f7c00181a5fb2ddf79ae00b4e10e`
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func TestPrecompile(t *testing.T) {
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assert.Equal(t, params.P256VerifyGas, Precompile{}.RequiredGas(nil), "RequiredGas()")
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type testCase struct {
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name string
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in []byte
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wantSuccess bool
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}
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tests := []testCase{
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{
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name: "empty input",
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},
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{
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name: "input too short",
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in: make([]byte, inputLen-1),
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},
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{
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name: "input too long",
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in: make([]byte, inputLen+1),
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},
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{
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name: "pub key at infinity",
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in: make([]byte, inputLen),
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},
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{
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name: "pub key not on curve",
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in: []byte{inputLen - 1: 1},
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},
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{
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name: "ulerdogan",
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in: common.Hex2Bytes(ulerdoganTestCase),
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wantSuccess: true,
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},
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}
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for range 50 {
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priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
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require.NoError(t, err, "ecdsa.GenerateKey(elliptic.P256(), crypto/rand.Reader)")
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for range 50 {
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var hash [32]byte
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_, err := rand.Read(hash[:])
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require.NoErrorf(t, err, "crypto/rand.Read(%T)", hash)
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in, err := Sign(priv, hash)
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require.NoErrorf(t, err, "Sign([P256 key], %#x)", hash)
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tests = append(tests, testCase{
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name: "fuzz",
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in: in,
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wantSuccess: true,
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})
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}
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}
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for _, tt := range tests {
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t.Run(tt.name, func(t *testing.T) {
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got, err := Precompile{}.Run(tt.in)
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require.NoError(t, err, "Run() always returns nil, even on verification failure")
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var want []byte
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if tt.wantSuccess {
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want = common.LeftPadBytes([]byte{1}, 32)
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}
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assert.Equal(t, want, got)
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})
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}
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}
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func BenchmarkPrecompile(b *testing.B) {
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in := common.Hex2Bytes(ulerdoganTestCase)
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var p Precompile
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for range b.N {
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p.Run(in)
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}
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}
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func TestViaEVM(t *testing.T) {
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addr := common.Address{42}
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hooks := hookstest.Stub{
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PrecompileOverrides: map[common.Address]libevm.PrecompiledContract{
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addr: Precompile{},
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},
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}
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hooks.Register(t)
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_, evm := ethtest.NewZeroEVM(t)
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in := common.Hex2Bytes(ulerdoganTestCase)
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got, _, err := evm.Call(vm.AccountRef{}, addr, in, 25000, uint256.NewInt(0))
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require.NoError(t, err)
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assert.Equal(t, []byte{31: 1}, got)
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}

‎params/protocol_params.libevm.go‎

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// Copyright 2025 the libevm authors.
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//
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// The libevm additions to go-ethereum are free software: you can redistribute
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// them and/or modify them under the terms of the GNU Lesser General Public License
5+
// as published by the Free Software Foundation, either version 3 of the License,
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// or (at your option) any later version.
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//
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// The libevm additions are distributed in the hope that they will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
10+
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
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// General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see
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// <http://www.gnu.org/licenses/>.
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package params
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// P256VerifyGas is the gas required by the RIP-7212 precompile for P256 ECDSA
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// verification.
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const P256VerifyGas uint64 = 3450

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