EIP-7212: precompile for secp256r1 curve

core/vm/contracts.go

@@ -30,6 +30,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto/bls12381"
 	"github.com/ethereum/go-ethereum/crypto/bn256"
 	"github.com/ethereum/go-ethereum/crypto/kzg4844"
+	"github.com/ethereum/go-ethereum/crypto/secp256r1"
 	"github.com/ethereum/go-ethereum/params"
 	"golang.org/x/crypto/ripemd160"
 )
@@ -121,6 +122,12 @@ var PrecompiledContractsBLS = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{18}): &bls12381MapG2{},
 }
 
+// PrecompiledContractsP256Verify contains the precompiled Ethereum
+// contract specified in EIP-7212. This is exported for testing purposes.
+var PrecompiledContractsP256Verify = map[common.Address]PrecompiledContract{
+	common.BytesToAddress([]byte{19}): &p256Verify{},
+}
+
 var (
 	PrecompiledAddressesCancun    []common.Address
 	PrecompiledAddressesBerlin    []common.Address
@@ -1135,3 +1142,37 @@ func kZGToVersionedHash(kzg kzg4844.Commitment) common.Hash {
 
 	return h
 }
+
+// P256VERIFY (secp256r1 signature verification)
+// implemented as a native contract
+type p256Verify struct{}
+
+// RequiredGas returns the gas required to execute the precompiled contract
+func (c *p256Verify) RequiredGas(input []byte) uint64 {
+	return params.P256VerifyGas
+}
+
+// Run executes the precompiled contract with given 160 bytes of param, returning the output and the used gas
+func (c *p256Verify) Run(input []byte) ([]byte, error) {
+	// Required input length is 160 bytes
+	const p256VerifyInputLength = 160
+	// Check the input length
+	if len(input) != p256VerifyInputLength {
+		// Input length is invalid
+		return nil, nil
+	}
+
+	// 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 secp256r1.Verify(hash, r, s, x, y) {
+		// Signature is valid
+		return common.LeftPadBytes(common.Big1.Bytes(), 32), nil
+	} else {
+		// Signature is invalid
+		return nil, nil
+	}
+}

core/vm/contracts_test.go

@@ -67,6 +67,8 @@ var allPrecompiles = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{0x0f, 0x10}): &bls12381Pairing{},
 	common.BytesToAddress([]byte{0x0f, 0x11}): &bls12381MapG1{},
 	common.BytesToAddress([]byte{0x0f, 0x12}): &bls12381MapG2{},
+
+  common.BytesToAddress([]byte{19}):   &p256Verify{},
 }
 
 // EIP-152 test vectors
@@ -395,3 +397,15 @@ func BenchmarkPrecompiledBLS12381G2MultiExpWorstCase(b *testing.B) {
 	}
 	benchmarkPrecompiled("0f", testcase, b)
 }
+
+// Benchmarks the sample inputs from the P256VERIFY precompile.
+func BenchmarkPrecompiledP256Verify(bench *testing.B) {
+	t := precompiledTest{
+		Input:    "4cee90eb86eaa050036147a12d49004b6b9c72bd725d39d4785011fe190f0b4da73bd4903f0ce3b639bbbf6e8e80d16931ff4bcf5993d58468e8fb19086e8cac36dbcd03009df8c59286b162af3bd7fcc0450c9aa81be5d10d312af6c66b1d604aebd3099c618202fcfe16ae7770b0c49ab5eadf74b754204a3bb6060e44eff37618b065f9832de4ca6ca971a7a1adc826d0f7c00181a5fb2ddf79ae00b4e10e",
+		Expected: "0000000000000000000000000000000000000000000000000000000000000001",
+		Name:     "p256Verify",
+	}
+	benchmarkPrecompiled("13", t, bench)
+}
+
+func TestPrecompiledP256Verify(t *testing.T) { testJson("p256Verify", "13", t) }

core/vm/testdata/precompiles/p256Verify.json

@@ -0,0 +1,9 @@
+[ 
+    {
+      "Input": "4cee90eb86eaa050036147a12d49004b6b9c72bd725d39d4785011fe190f0b4da73bd4903f0ce3b639bbbf6e8e80d16931ff4bcf5993d58468e8fb19086e8cac36dbcd03009df8c59286b162af3bd7fcc0450c9aa81be5d10d312af6c66b1d604aebd3099c618202fcfe16ae7770b0c49ab5eadf74b754204a3bb6060e44eff37618b065f9832de4ca6ca971a7a1adc826d0f7c00181a5fb2ddf79ae00b4e10e",
+      "Expected": "0000000000000000000000000000000000000000000000000000000000000001",
+      "Gas": 3450,
+      "Name": "CallP256Verify",
+      "NoBenchmark": false
+    }
+  ]

crypto/secp256r1/publickey.go

@@ -0,0 +1,26 @@
+package secp256r1
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"math/big"
+)
+
+// Generates approptiate public key format from given coordinates
+func newPublicKey(x, y *big.Int) *ecdsa.PublicKey {
+	// Check if the given coordinates are valid
+	if x == nil || y == nil || !elliptic.P256().IsOnCurve(x, y) {
+		return nil
+	}
+
+	// Check if the given coordinates are the reference point (infinity)
+	if x.Sign() == 0 && y.Sign() == 0 {
+		return nil
+	}
+
+	return &ecdsa.PublicKey{
+		Curve: elliptic.P256(),
+		X:     x,
+		Y:     y,
+	}
+}

crypto/secp256r1/verifier.go

@@ -0,0 +1,21 @@
+package secp256r1
+
+import (
+	"crypto/ecdsa"
+	"math/big"
+)
+
+// Verifies the given signature (r, s) for the given hash and public key (x, y).
+func Verify(hash []byte, r, s, x, y *big.Int) bool {
+	// Create the public key format
+	publicKey := newPublicKey(x, y)
+
+	// Check if they are invalid public key coordinates
+	if publicKey == nil {
+		return false
+	}
+
+	// Verify the signature with the public key,
+	// then return true if it's valid, false otherwise
+	return ecdsa.Verify(publicKey, hash, r, s)
+}

params/protocol_params.go

@@ -159,6 +159,8 @@ const (
 	Bls12381MapG1Gas          uint64 = 5500   // Gas price for BLS12-381 mapping field element to G1 operation
 	Bls12381MapG2Gas          uint64 = 110000 // Gas price for BLS12-381 mapping field element to G2 operation
 
+	P256VerifyGas uint64 = 3450 // secp256r1 elliptic curve signature verifier gas price
+
 	// The Refund Quotient is the cap on how much of the used gas can be refunded. Before EIP-3529,
 	// up to half the consumed gas could be refunded. Redefined as 1/5th in EIP-3529
 	RefundQuotient        uint64 = 2