RIP-7212: Precompile for secp256r1 Curve Support, Reference Implementation

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"
 )
@@ -107,6 +108,12 @@ var PrecompiledContractsCancun = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{0x0a}): &kzgPointEvaluation{},
 }
 
+// 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{0x01, 0x00}): &p256Verify{},
+}
+
 // PrecompiledContractsBLS contains the set of pre-compiled Ethereum
 // contracts specified in EIP-2537. These are exported for testing purposes.
 var PrecompiledContractsBLS = map[common.Address]PrecompiledContract{
@@ -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

@@ -58,6 +58,8 @@ var allPrecompiles = map[common.Address]PrecompiledContract{
 	common.BytesToAddress([]byte{9}):    &blake2F{},
 	common.BytesToAddress([]byte{0x0a}): &kzgPointEvaluation{},
 
+	common.BytesToAddress([]byte{0x01, 0x00}): &p256Verify{},
+
 	common.BytesToAddress([]byte{0x0f, 0x0a}): &bls12381G1Add{},
 	common.BytesToAddress([]byte{0x0f, 0x0b}): &bls12381G1Mul{},
 	common.BytesToAddress([]byte{0x0f, 0x0c}): &bls12381G1MultiExp{},
@@ -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("100", t, bench)
+}
+
+func TestPrecompiledP256Verify(t *testing.T) { testJson("p256Verify", "100", t) }