core/vm: implement secp256r1 verifier precompiled

core/vm/contracts.go

@@ -28,6 +28,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto/blake2b"
 	"github.com/ethereum/go-ethereum/crypto/bls12381"
 	"github.com/ethereum/go-ethereum/crypto/bn256"
+	"github.com/ethereum/go-ethereum/crypto/secp256r1"
 	"github.com/ethereum/go-ethereum/params"
 	"golang.org/x/crypto/ripemd160"
 )
@@ -104,6 +105,12 @@ var PrecompiledContractsBLS = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{18}): &bls12381MapG2{},
 }
 
+// PrecompiledContractsEcverify contains the precompiled Ethereum
+// contract specified in EIP-N. This is exported for testing purposes.
+var PrecompiledContractsEcverify = map[common.Address]PrecompiledContract{
+	common.BytesToAddress([]byte{19}): &ecverify{},
+}
+
 var (
 	PrecompiledAddressesBerlin    []common.Address
 	PrecompiledAddressesIstanbul  []common.Address
@@ -1048,3 +1055,33 @@ func (c *bls12381MapG2) Run(input []byte) ([]byte, error) {
 	// Encode the G2 point to 256 bytes
 	return g.EncodePoint(r), nil
 }
+
+// ECVERIFY (secp256r1 signature verification)
+// implemented as a native contract
+type ecverify struct{}
+
+// RequiredGas returns the gas required to execute the precompiled contract
+func (c *ecverify) RequiredGas(input []byte) uint64 {
+	return params.EcverifyGas
+}
+
+// Run executes the precompiled contract, returning the output and the used gas
+func (c *ecverify) Run(input []byte) ([]byte, error) {
+	// Required input length is 160 bytes
+	const ecverifyInputLength = 160
+
+	// "input" is (hash, r, s, x, y), each 32 bytes
+	input = common.RightPadBytes(input, ecverifyInputLength)
+
+	// Extract the hash, r, s, x, y from the input
+	hash := input[0:32]
+	r, s := new(big.Int).SetBytes(input[32:64]), new(big.Int).SetBytes(input[64:96])
+	x, y := new(big.Int).SetBytes(input[96:128]), new(big.Int).SetBytes(input[128:160])
+
+	// Verify the secp256r1 signature
+	if result, err := secp256r1.Verify(hash, r, s, x, y); err != nil {
+		return nil, err
+	} else {
+		return result, nil
+	}
+}

core/vm/contracts_test.go

@@ -65,6 +65,7 @@ var allPrecompiles = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{16}):   &bls12381Pairing{},
 	common.BytesToAddress([]byte{17}):   &bls12381MapG1{},
 	common.BytesToAddress([]byte{18}):   &bls12381MapG2{},
+	common.BytesToAddress([]byte{19}):   &ecverify{},
 }
 
 // EIP-152 test vectors
@@ -391,3 +392,15 @@ func BenchmarkPrecompiledBLS12381G2MultiExpWorstCase(b *testing.B) {
 	}
 	benchmarkPrecompiled("0f", testcase, b)
 }
+
+// Benchmarks the sample inputs from the ECVERIFY precompile.
+func BenchmarkPrecompiledEcverify(bench *testing.B) {
+	t := precompiledTest{
+		Input:    "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b98243744ca2b25ce52b927841120de9d5e5a454acabea2ebacaa1f76850934cb0c7c818200fa5e4b4607eeea9593071a6097b132d77c10661c441b5a66eb36856e1251c078c2c1367932e25bf657f6b2e378a26a27e238196295e1c59e2225d372fe603c229d85ea9eb0b090274c59a0600becd11d0df3f91fe44677977119c4ff03",
+		Expected: "0000000000000000000000000000000000000000000000000000000000000001",
+		Name:     "ecverify",
+	}
+	benchmarkPrecompiled("13", t, bench)
+}
+
+func TestPrecompiledEcverify(t *testing.T) { testJson("ecverify", "13", t) }

core/vm/testdata/precompiles/ecverify.json

@@ -0,0 +1,9 @@
+[ 
+    {
+      "Input": "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b98243744ca2b25ce52b927841120de9d5e5a454acabea2ebacaa1f76850934cb0c7c818200fa5e4b4607eeea9593071a6097b132d77c10661c441b5a66eb36856e1251c078c2c1367932e25bf657f6b2e378a26a27e238196295e1c59e2225d372fe603c229d85ea9eb0b090274c59a0600becd11d0df3f91fe44677977119c4ff03",
+      "Expected": "0000000000000000000000000000000000000000000000000000000000000001",
+      "Gas": 3450,
+      "Name": "CallEcverify",
+      "NoBenchmark": false
+    }
+  ]