github.com/theQRL/go-zond@v0.1.1/core/vm/contracts.go (about)

     1  // Copyright 2014 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package vm
    18  
    19  import (
    20  	"bytes"
    21  	"crypto/sha256"
    22  	"encoding/binary"
    23  	"errors"
    24  	"fmt"
    25  	"math/big"
    26  
    27  	pkgerrors "github.com/pkg/errors"
    28  	ssz "github.com/prysmaticlabs/fastssz"
    29  	"github.com/theQRL/go-zond/common"
    30  	"github.com/theQRL/go-zond/common/math"
    31  	"github.com/theQRL/go-zond/crypto/blake2b"
    32  	"github.com/theQRL/go-zond/crypto/bls12381"
    33  	"github.com/theQRL/go-zond/crypto/bn256"
    34  	"github.com/theQRL/go-zond/crypto/kzg4844"
    35  	"github.com/theQRL/go-zond/params"
    36  	"golang.org/x/crypto/ripemd160"
    37  )
    38  
    39  // PrecompiledContract is the basic interface for native Go contracts. The implementation
    40  // requires a deterministic gas count based on the input size of the Run method of the
    41  // contract.
    42  type PrecompiledContract interface {
    43  	RequiredGas(input []byte) uint64  // RequiredPrice calculates the contract gas use
    44  	Run(input []byte) ([]byte, error) // Run runs the precompiled contract
    45  }
    46  
    47  // PrecompiledContractsHomestead contains the default set of pre-compiled Ethereum
    48  // contracts used in the Frontier and Homestead releases.
    49  var PrecompiledContractsHomestead = map[common.Address]PrecompiledContract{
    50  	// common.BytesToAddress([]byte{1}): &ecrecover{},
    51  	common.BytesToAddress([]byte{1}): &depositroot{},
    52  	common.BytesToAddress([]byte{2}): &sha256hash{},
    53  	common.BytesToAddress([]byte{3}): &ripemd160hash{},
    54  	common.BytesToAddress([]byte{4}): &dataCopy{},
    55  }
    56  
    57  // PrecompiledContractsByzantium contains the default set of pre-compiled Ethereum
    58  // contracts used in the Byzantium release.
    59  var PrecompiledContractsByzantium = map[common.Address]PrecompiledContract{
    60  	// common.BytesToAddress([]byte{1}): &ecrecover{},
    61  	common.BytesToAddress([]byte{1}): &depositroot{},
    62  	common.BytesToAddress([]byte{2}): &sha256hash{},
    63  	common.BytesToAddress([]byte{3}): &ripemd160hash{},
    64  	common.BytesToAddress([]byte{4}): &dataCopy{},
    65  	common.BytesToAddress([]byte{5}): &bigModExp{eip2565: false},
    66  	common.BytesToAddress([]byte{6}): &bn256AddByzantium{},
    67  	common.BytesToAddress([]byte{7}): &bn256ScalarMulByzantium{},
    68  	common.BytesToAddress([]byte{8}): &bn256PairingByzantium{},
    69  }
    70  
    71  // PrecompiledContractsIstanbul contains the default set of pre-compiled Ethereum
    72  // contracts used in the Istanbul release.
    73  var PrecompiledContractsIstanbul = map[common.Address]PrecompiledContract{
    74  	// common.BytesToAddress([]byte{1}): &ecrecover{},
    75  	common.BytesToAddress([]byte{1}): &depositroot{},
    76  	common.BytesToAddress([]byte{2}): &sha256hash{},
    77  	common.BytesToAddress([]byte{3}): &ripemd160hash{},
    78  	common.BytesToAddress([]byte{4}): &dataCopy{},
    79  	common.BytesToAddress([]byte{5}): &bigModExp{eip2565: false},
    80  	common.BytesToAddress([]byte{6}): &bn256AddIstanbul{},
    81  	common.BytesToAddress([]byte{7}): &bn256ScalarMulIstanbul{},
    82  	common.BytesToAddress([]byte{8}): &bn256PairingIstanbul{},
    83  	common.BytesToAddress([]byte{9}): &blake2F{},
    84  }
    85  
    86  // PrecompiledContractsBerlin contains the default set of pre-compiled Ethereum
    87  // contracts used in the Berlin release.
    88  var PrecompiledContractsBerlin = map[common.Address]PrecompiledContract{
    89  	// common.BytesToAddress([]byte{1}): &ecrecover{},
    90  	common.BytesToAddress([]byte{1}): &depositroot{},
    91  	common.BytesToAddress([]byte{2}): &sha256hash{},
    92  	common.BytesToAddress([]byte{3}): &ripemd160hash{},
    93  	common.BytesToAddress([]byte{4}): &dataCopy{},
    94  	common.BytesToAddress([]byte{5}): &bigModExp{eip2565: true},
    95  	common.BytesToAddress([]byte{6}): &bn256AddIstanbul{},
    96  	common.BytesToAddress([]byte{7}): &bn256ScalarMulIstanbul{},
    97  	common.BytesToAddress([]byte{8}): &bn256PairingIstanbul{},
    98  	common.BytesToAddress([]byte{9}): &blake2F{},
    99  }
   100  
   101  // PrecompiledContractsCancun contains the default set of pre-compiled Ethereum
   102  // contracts used in the Cancun release.
   103  var PrecompiledContractsCancun = map[common.Address]PrecompiledContract{
   104  	common.BytesToAddress([]byte{1}):    &depositroot{},
   105  	common.BytesToAddress([]byte{2}):    &sha256hash{},
   106  	common.BytesToAddress([]byte{3}):    &ripemd160hash{},
   107  	common.BytesToAddress([]byte{4}):    &dataCopy{},
   108  	common.BytesToAddress([]byte{5}):    &bigModExp{eip2565: true},
   109  	common.BytesToAddress([]byte{6}):    &bn256AddIstanbul{},
   110  	common.BytesToAddress([]byte{7}):    &bn256ScalarMulIstanbul{},
   111  	common.BytesToAddress([]byte{8}):    &bn256PairingIstanbul{},
   112  	common.BytesToAddress([]byte{9}):    &blake2F{},
   113  	common.BytesToAddress([]byte{0x0a}): &kzgPointEvaluation{},
   114  }
   115  
   116  // PrecompiledContractsBLS contains the set of pre-compiled Ethereum
   117  // contracts specified in EIP-2537. These are exported for testing purposes.
   118  var PrecompiledContractsBLS = map[common.Address]PrecompiledContract{
   119  	common.BytesToAddress([]byte{10}): &bls12381G1Add{},
   120  	common.BytesToAddress([]byte{11}): &bls12381G1Mul{},
   121  	common.BytesToAddress([]byte{12}): &bls12381G1MultiExp{},
   122  	common.BytesToAddress([]byte{13}): &bls12381G2Add{},
   123  	common.BytesToAddress([]byte{14}): &bls12381G2Mul{},
   124  	common.BytesToAddress([]byte{15}): &bls12381G2MultiExp{},
   125  	common.BytesToAddress([]byte{16}): &bls12381Pairing{},
   126  	common.BytesToAddress([]byte{17}): &bls12381MapG1{},
   127  	common.BytesToAddress([]byte{18}): &bls12381MapG2{},
   128  }
   129  
   130  var (
   131  	PrecompiledAddressesCancun    []common.Address
   132  	PrecompiledAddressesBerlin    []common.Address
   133  	PrecompiledAddressesIstanbul  []common.Address
   134  	PrecompiledAddressesByzantium []common.Address
   135  	PrecompiledAddressesHomestead []common.Address
   136  )
   137  
   138  func init() {
   139  	for k := range PrecompiledContractsHomestead {
   140  		PrecompiledAddressesHomestead = append(PrecompiledAddressesHomestead, k)
   141  	}
   142  	for k := range PrecompiledContractsByzantium {
   143  		PrecompiledAddressesByzantium = append(PrecompiledAddressesByzantium, k)
   144  	}
   145  	for k := range PrecompiledContractsIstanbul {
   146  		PrecompiledAddressesIstanbul = append(PrecompiledAddressesIstanbul, k)
   147  	}
   148  	for k := range PrecompiledContractsBerlin {
   149  		PrecompiledAddressesBerlin = append(PrecompiledAddressesBerlin, k)
   150  	}
   151  	for k := range PrecompiledContractsCancun {
   152  		PrecompiledAddressesCancun = append(PrecompiledAddressesCancun, k)
   153  	}
   154  }
   155  
   156  // ActivePrecompiles returns the precompiles enabled with the current configuration.
   157  func ActivePrecompiles(rules params.Rules) []common.Address {
   158  	switch {
   159  	case rules.IsCancun:
   160  		return PrecompiledAddressesCancun
   161  	case rules.IsBerlin:
   162  		return PrecompiledAddressesBerlin
   163  	case rules.IsIstanbul:
   164  		return PrecompiledAddressesIstanbul
   165  	case rules.IsByzantium:
   166  		return PrecompiledAddressesByzantium
   167  	default:
   168  		return PrecompiledAddressesHomestead
   169  	}
   170  }
   171  
   172  // RunPrecompiledContract runs and evaluates the output of a precompiled contract.
   173  // It returns
   174  // - the returned bytes,
   175  // - the _remaining_ gas,
   176  // - any error that occurred
   177  func RunPrecompiledContract(p PrecompiledContract, input []byte, suppliedGas uint64) (ret []byte, remainingGas uint64, err error) {
   178  	gasCost := p.RequiredGas(input)
   179  	if suppliedGas < gasCost {
   180  		return nil, 0, ErrOutOfGas
   181  	}
   182  	suppliedGas -= gasCost
   183  	output, err := p.Run(input)
   184  	return output, suppliedGas, err
   185  }
   186  
   187  /*
   188  // ECRECOVER implemented as a native contract.
   189  type ecrecover struct{}
   190  
   191  func (c *ecrecover) RequiredGas(input []byte) uint64 {
   192  	return params.EcrecoverGas
   193  }
   194  
   195  func (c *ecrecover) Run(input []byte) ([]byte, error) {
   196  	const ecRecoverInputLength = 128
   197  
   198  	input = common.RightPadBytes(input, ecRecoverInputLength)
   199  	// "input" is (hash, v, r, s), each 32 bytes
   200  	// but for ecrecover we want (r, s, v)
   201  
   202  	r := new(big.Int).SetBytes(input[64:96])
   203  	s := new(big.Int).SetBytes(input[96:128])
   204  	v := input[63] - 27
   205  
   206  	// tighter sig s values input homestead only apply to tx sigs
   207  	if !allZero(input[32:63]) || !crypto.ValidateSignatureValues(v, r, s, false) {
   208  		return nil, nil
   209  	}
   210  	// We must make sure not to modify the 'input', so placing the 'v' along with
   211  	// the signature needs to be done on a new allocation
   212  	sig := make([]byte, 65)
   213  	copy(sig, input[64:128])
   214  	sig[64] = v
   215  	// v needs to be at the end for libsecp256k1
   216  	pubKey, err := crypto.Ecrecover(input[:32], sig)
   217  	// make sure the public key is a valid one
   218  	if err != nil {
   219  		return nil, nil
   220  	}
   221  
   222  	// the first byte of pubkey is bitcoin heritage
   223  	return common.LeftPadBytes(crypto.Keccak256(pubKey[1:])[12:], 32), nil
   224  }
   225  */
   226  
   227  type depositroot struct{}
   228  
   229  // TODO(rgeraldes24): review required gas
   230  func (c *depositroot) RequiredGas(input []byte) uint64 {
   231  	return params.DepositrootGas
   232  }
   233  
   234  // TODO(rgeraldes24): assess why extra bytes are being added
   235  func (c *depositroot) Run(input []byte) ([]byte, error) {
   236  	const depositRootInputLength = 7508 // 7251 in the correct version
   237  	input = common.RightPadBytes(input, depositRootInputLength)
   238  	// "input" is (pubkey, withdrawal_credentials, amount, signature)
   239  	// pubkey is 2592 bytes
   240  	// withdrawal_credentials is 32 bytes
   241  	// signature is 4595 bytes
   242  
   243  	var amount uint64
   244  
   245  	buf := bytes.NewReader(input[2848:2880])
   246  	err := binary.Read(buf, binary.LittleEndian, &amount)
   247  	if err != nil {
   248  		return nil, err
   249  	}
   250  
   251  	data := &depositdata{
   252  		PublicKey:             input[160:2752],  // 2592 bytes
   253  		WithdrawalCredentials: input[2784:2816], // 32 bytes
   254  		Amount:                amount,           // 32 bytes
   255  		Signature:             input[2912:7507], // 4595 bytes
   256  	}
   257  	h, err := data.HashTreeRoot()
   258  	if err != nil {
   259  		return nil, pkgerrors.Wrap(err, "could not hash tree root deposit data item")
   260  	}
   261  
   262  	return h[:], nil
   263  }
   264  
   265  type depositdata struct {
   266  	PublicKey             []byte
   267  	WithdrawalCredentials []byte
   268  	Amount                uint64
   269  	Signature             []byte
   270  }
   271  
   272  // HashTreeRoot ssz hashes the Deposit_Data object
   273  func (d *depositdata) HashTreeRoot() ([32]byte, error) {
   274  	return ssz.HashWithDefaultHasher(d)
   275  }
   276  
   277  // HashTreeRootWith ssz hashes the Deposit_Data object with a hasher
   278  func (d *depositdata) HashTreeRootWith(hh *ssz.Hasher) (err error) {
   279  	indx := hh.Index()
   280  
   281  	// Field (0) 'Pubkey'
   282  	if size := len(d.PublicKey); size != 2592 {
   283  		err = ssz.ErrBytesLengthFn("--.Pubkey", size, 2592)
   284  		return
   285  	}
   286  	hh.PutBytes(d.PublicKey)
   287  
   288  	// Field (1) 'WithdrawalCredentials'
   289  	if size := len(d.WithdrawalCredentials); size != 32 {
   290  		err = ssz.ErrBytesLengthFn("--.WithdrawalCredentials", size, 32)
   291  		return
   292  	}
   293  	hh.PutBytes(d.WithdrawalCredentials)
   294  
   295  	// Field (2) 'Amount'
   296  	hh.PutUint64(d.Amount)
   297  
   298  	// Field (3) 'Signature'
   299  	if size := len(d.Signature); size != 4595 {
   300  		err = ssz.ErrBytesLengthFn("--.Signature", size, 4595)
   301  		return
   302  	}
   303  	hh.PutBytes(d.Signature)
   304  
   305  	if ssz.EnableVectorizedHTR {
   306  		hh.MerkleizeVectorizedHTR(indx)
   307  	} else {
   308  		hh.Merkleize(indx)
   309  	}
   310  	return
   311  }
   312  
   313  // SHA256 implemented as a native contract.
   314  type sha256hash struct{}
   315  
   316  // RequiredGas returns the gas required to execute the pre-compiled contract.
   317  //
   318  // This method does not require any overflow checking as the input size gas costs
   319  // required for anything significant is so high it's impossible to pay for.
   320  func (c *sha256hash) RequiredGas(input []byte) uint64 {
   321  	return uint64(len(input)+31)/32*params.Sha256PerWordGas + params.Sha256BaseGas
   322  }
   323  func (c *sha256hash) Run(input []byte) ([]byte, error) {
   324  	h := sha256.Sum256(input)
   325  	return h[:], nil
   326  }
   327  
   328  // RIPEMD160 implemented as a native contract.
   329  type ripemd160hash struct{}
   330  
   331  // RequiredGas returns the gas required to execute the pre-compiled contract.
   332  //
   333  // This method does not require any overflow checking as the input size gas costs
   334  // required for anything significant is so high it's impossible to pay for.
   335  func (c *ripemd160hash) RequiredGas(input []byte) uint64 {
   336  	return uint64(len(input)+31)/32*params.Ripemd160PerWordGas + params.Ripemd160BaseGas
   337  }
   338  func (c *ripemd160hash) Run(input []byte) ([]byte, error) {
   339  	ripemd := ripemd160.New()
   340  	ripemd.Write(input)
   341  	return common.LeftPadBytes(ripemd.Sum(nil), 32), nil
   342  }
   343  
   344  // data copy implemented as a native contract.
   345  type dataCopy struct{}
   346  
   347  // RequiredGas returns the gas required to execute the pre-compiled contract.
   348  //
   349  // This method does not require any overflow checking as the input size gas costs
   350  // required for anything significant is so high it's impossible to pay for.
   351  func (c *dataCopy) RequiredGas(input []byte) uint64 {
   352  	return uint64(len(input)+31)/32*params.IdentityPerWordGas + params.IdentityBaseGas
   353  }
   354  func (c *dataCopy) Run(in []byte) ([]byte, error) {
   355  	return common.CopyBytes(in), nil
   356  }
   357  
   358  // bigModExp implements a native big integer exponential modular operation.
   359  type bigModExp struct {
   360  	eip2565 bool
   361  }
   362  
   363  var (
   364  	big0      = big.NewInt(0)
   365  	big1      = big.NewInt(1)
   366  	big3      = big.NewInt(3)
   367  	big4      = big.NewInt(4)
   368  	big7      = big.NewInt(7)
   369  	big8      = big.NewInt(8)
   370  	big16     = big.NewInt(16)
   371  	big20     = big.NewInt(20)
   372  	big32     = big.NewInt(32)
   373  	big64     = big.NewInt(64)
   374  	big96     = big.NewInt(96)
   375  	big480    = big.NewInt(480)
   376  	big1024   = big.NewInt(1024)
   377  	big3072   = big.NewInt(3072)
   378  	big199680 = big.NewInt(199680)
   379  )
   380  
   381  // modexpMultComplexity implements bigModexp multComplexity formula, as defined in EIP-198
   382  //
   383  //	def mult_complexity(x):
   384  //		if x <= 64: return x ** 2
   385  //		elif x <= 1024: return x ** 2 // 4 + 96 * x - 3072
   386  //		else: return x ** 2 // 16 + 480 * x - 199680
   387  //
   388  // where is x is max(length_of_MODULUS, length_of_BASE)
   389  func modexpMultComplexity(x *big.Int) *big.Int {
   390  	switch {
   391  	case x.Cmp(big64) <= 0:
   392  		x.Mul(x, x) // x ** 2
   393  	case x.Cmp(big1024) <= 0:
   394  		// (x ** 2 // 4 ) + ( 96 * x - 3072)
   395  		x = new(big.Int).Add(
   396  			new(big.Int).Div(new(big.Int).Mul(x, x), big4),
   397  			new(big.Int).Sub(new(big.Int).Mul(big96, x), big3072),
   398  		)
   399  	default:
   400  		// (x ** 2 // 16) + (480 * x - 199680)
   401  		x = new(big.Int).Add(
   402  			new(big.Int).Div(new(big.Int).Mul(x, x), big16),
   403  			new(big.Int).Sub(new(big.Int).Mul(big480, x), big199680),
   404  		)
   405  	}
   406  	return x
   407  }
   408  
   409  // RequiredGas returns the gas required to execute the pre-compiled contract.
   410  func (c *bigModExp) RequiredGas(input []byte) uint64 {
   411  	var (
   412  		baseLen = new(big.Int).SetBytes(getData(input, 0, 32))
   413  		expLen  = new(big.Int).SetBytes(getData(input, 32, 32))
   414  		modLen  = new(big.Int).SetBytes(getData(input, 64, 32))
   415  	)
   416  	if len(input) > 96 {
   417  		input = input[96:]
   418  	} else {
   419  		input = input[:0]
   420  	}
   421  	// Retrieve the head 32 bytes of exp for the adjusted exponent length
   422  	var expHead *big.Int
   423  	if big.NewInt(int64(len(input))).Cmp(baseLen) <= 0 {
   424  		expHead = new(big.Int)
   425  	} else {
   426  		if expLen.Cmp(big32) > 0 {
   427  			expHead = new(big.Int).SetBytes(getData(input, baseLen.Uint64(), 32))
   428  		} else {
   429  			expHead = new(big.Int).SetBytes(getData(input, baseLen.Uint64(), expLen.Uint64()))
   430  		}
   431  	}
   432  	// Calculate the adjusted exponent length
   433  	var msb int
   434  	if bitlen := expHead.BitLen(); bitlen > 0 {
   435  		msb = bitlen - 1
   436  	}
   437  	adjExpLen := new(big.Int)
   438  	if expLen.Cmp(big32) > 0 {
   439  		adjExpLen.Sub(expLen, big32)
   440  		adjExpLen.Mul(big8, adjExpLen)
   441  	}
   442  	adjExpLen.Add(adjExpLen, big.NewInt(int64(msb)))
   443  	// Calculate the gas cost of the operation
   444  	gas := new(big.Int).Set(math.BigMax(modLen, baseLen))
   445  	if c.eip2565 {
   446  		// EIP-2565 has three changes
   447  		// 1. Different multComplexity (inlined here)
   448  		// in EIP-2565 (https://eips.ethereum.org/EIPS/eip-2565):
   449  		//
   450  		// def mult_complexity(x):
   451  		//    ceiling(x/8)^2
   452  		//
   453  		//where is x is max(length_of_MODULUS, length_of_BASE)
   454  		gas = gas.Add(gas, big7)
   455  		gas = gas.Div(gas, big8)
   456  		gas.Mul(gas, gas)
   457  
   458  		gas.Mul(gas, math.BigMax(adjExpLen, big1))
   459  		// 2. Different divisor (`GQUADDIVISOR`) (3)
   460  		gas.Div(gas, big3)
   461  		if gas.BitLen() > 64 {
   462  			return math.MaxUint64
   463  		}
   464  		// 3. Minimum price of 200 gas
   465  		if gas.Uint64() < 200 {
   466  			return 200
   467  		}
   468  		return gas.Uint64()
   469  	}
   470  	gas = modexpMultComplexity(gas)
   471  	gas.Mul(gas, math.BigMax(adjExpLen, big1))
   472  	gas.Div(gas, big20)
   473  
   474  	if gas.BitLen() > 64 {
   475  		return math.MaxUint64
   476  	}
   477  	return gas.Uint64()
   478  }
   479  
   480  func (c *bigModExp) Run(input []byte) ([]byte, error) {
   481  	var (
   482  		baseLen = new(big.Int).SetBytes(getData(input, 0, 32)).Uint64()
   483  		expLen  = new(big.Int).SetBytes(getData(input, 32, 32)).Uint64()
   484  		modLen  = new(big.Int).SetBytes(getData(input, 64, 32)).Uint64()
   485  	)
   486  	if len(input) > 96 {
   487  		input = input[96:]
   488  	} else {
   489  		input = input[:0]
   490  	}
   491  	// Handle a special case when both the base and mod length is zero
   492  	if baseLen == 0 && modLen == 0 {
   493  		return []byte{}, nil
   494  	}
   495  	// Retrieve the operands and execute the exponentiation
   496  	var (
   497  		base = new(big.Int).SetBytes(getData(input, 0, baseLen))
   498  		exp  = new(big.Int).SetBytes(getData(input, baseLen, expLen))
   499  		mod  = new(big.Int).SetBytes(getData(input, baseLen+expLen, modLen))
   500  		v    []byte
   501  	)
   502  	switch {
   503  	case mod.BitLen() == 0:
   504  		// Modulo 0 is undefined, return zero
   505  		return common.LeftPadBytes([]byte{}, int(modLen)), nil
   506  	case base.BitLen() == 1: // a bit length of 1 means it's 1 (or -1).
   507  		//If base == 1, then we can just return base % mod (if mod >= 1, which it is)
   508  		v = base.Mod(base, mod).Bytes()
   509  	default:
   510  		v = base.Exp(base, exp, mod).Bytes()
   511  	}
   512  	return common.LeftPadBytes(v, int(modLen)), nil
   513  }
   514  
   515  // newCurvePoint unmarshals a binary blob into a bn256 elliptic curve point,
   516  // returning it, or an error if the point is invalid.
   517  func newCurvePoint(blob []byte) (*bn256.G1, error) {
   518  	p := new(bn256.G1)
   519  	if _, err := p.Unmarshal(blob); err != nil {
   520  		return nil, err
   521  	}
   522  	return p, nil
   523  }
   524  
   525  // newTwistPoint unmarshals a binary blob into a bn256 elliptic curve point,
   526  // returning it, or an error if the point is invalid.
   527  func newTwistPoint(blob []byte) (*bn256.G2, error) {
   528  	p := new(bn256.G2)
   529  	if _, err := p.Unmarshal(blob); err != nil {
   530  		return nil, err
   531  	}
   532  	return p, nil
   533  }
   534  
   535  // runBn256Add implements the Bn256Add precompile, referenced by both
   536  // Byzantium and Istanbul operations.
   537  func runBn256Add(input []byte) ([]byte, error) {
   538  	x, err := newCurvePoint(getData(input, 0, 64))
   539  	if err != nil {
   540  		return nil, err
   541  	}
   542  	y, err := newCurvePoint(getData(input, 64, 64))
   543  	if err != nil {
   544  		return nil, err
   545  	}
   546  	res := new(bn256.G1)
   547  	res.Add(x, y)
   548  	return res.Marshal(), nil
   549  }
   550  
   551  // bn256Add implements a native elliptic curve point addition conforming to
   552  // Istanbul consensus rules.
   553  type bn256AddIstanbul struct{}
   554  
   555  // RequiredGas returns the gas required to execute the pre-compiled contract.
   556  func (c *bn256AddIstanbul) RequiredGas(input []byte) uint64 {
   557  	return params.Bn256AddGasIstanbul
   558  }
   559  
   560  func (c *bn256AddIstanbul) Run(input []byte) ([]byte, error) {
   561  	return runBn256Add(input)
   562  }
   563  
   564  // bn256AddByzantium implements a native elliptic curve point addition
   565  // conforming to Byzantium consensus rules.
   566  type bn256AddByzantium struct{}
   567  
   568  // RequiredGas returns the gas required to execute the pre-compiled contract.
   569  func (c *bn256AddByzantium) RequiredGas(input []byte) uint64 {
   570  	return params.Bn256AddGasByzantium
   571  }
   572  
   573  func (c *bn256AddByzantium) Run(input []byte) ([]byte, error) {
   574  	return runBn256Add(input)
   575  }
   576  
   577  // runBn256ScalarMul implements the Bn256ScalarMul precompile, referenced by
   578  // both Byzantium and Istanbul operations.
   579  func runBn256ScalarMul(input []byte) ([]byte, error) {
   580  	p, err := newCurvePoint(getData(input, 0, 64))
   581  	if err != nil {
   582  		return nil, err
   583  	}
   584  	res := new(bn256.G1)
   585  	res.ScalarMult(p, new(big.Int).SetBytes(getData(input, 64, 32)))
   586  	return res.Marshal(), nil
   587  }
   588  
   589  // bn256ScalarMulIstanbul implements a native elliptic curve scalar
   590  // multiplication conforming to Istanbul consensus rules.
   591  type bn256ScalarMulIstanbul struct{}
   592  
   593  // RequiredGas returns the gas required to execute the pre-compiled contract.
   594  func (c *bn256ScalarMulIstanbul) RequiredGas(input []byte) uint64 {
   595  	return params.Bn256ScalarMulGasIstanbul
   596  }
   597  
   598  func (c *bn256ScalarMulIstanbul) Run(input []byte) ([]byte, error) {
   599  	return runBn256ScalarMul(input)
   600  }
   601  
   602  // bn256ScalarMulByzantium implements a native elliptic curve scalar
   603  // multiplication conforming to Byzantium consensus rules.
   604  type bn256ScalarMulByzantium struct{}
   605  
   606  // RequiredGas returns the gas required to execute the pre-compiled contract.
   607  func (c *bn256ScalarMulByzantium) RequiredGas(input []byte) uint64 {
   608  	return params.Bn256ScalarMulGasByzantium
   609  }
   610  
   611  func (c *bn256ScalarMulByzantium) Run(input []byte) ([]byte, error) {
   612  	return runBn256ScalarMul(input)
   613  }
   614  
   615  var (
   616  	// true32Byte is returned if the bn256 pairing check succeeds.
   617  	true32Byte = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}
   618  
   619  	// false32Byte is returned if the bn256 pairing check fails.
   620  	false32Byte = make([]byte, 32)
   621  
   622  	// errBadPairingInput is returned if the bn256 pairing input is invalid.
   623  	errBadPairingInput = errors.New("bad elliptic curve pairing size")
   624  )
   625  
   626  // runBn256Pairing implements the Bn256Pairing precompile, referenced by both
   627  // Byzantium and Istanbul operations.
   628  func runBn256Pairing(input []byte) ([]byte, error) {
   629  	// Handle some corner cases cheaply
   630  	if len(input)%192 > 0 {
   631  		return nil, errBadPairingInput
   632  	}
   633  	// Convert the input into a set of coordinates
   634  	var (
   635  		cs []*bn256.G1
   636  		ts []*bn256.G2
   637  	)
   638  	for i := 0; i < len(input); i += 192 {
   639  		c, err := newCurvePoint(input[i : i+64])
   640  		if err != nil {
   641  			return nil, err
   642  		}
   643  		t, err := newTwistPoint(input[i+64 : i+192])
   644  		if err != nil {
   645  			return nil, err
   646  		}
   647  		cs = append(cs, c)
   648  		ts = append(ts, t)
   649  	}
   650  	// Execute the pairing checks and return the results
   651  	if bn256.PairingCheck(cs, ts) {
   652  		return true32Byte, nil
   653  	}
   654  	return false32Byte, nil
   655  }
   656  
   657  // bn256PairingIstanbul implements a pairing pre-compile for the bn256 curve
   658  // conforming to Istanbul consensus rules.
   659  type bn256PairingIstanbul struct{}
   660  
   661  // RequiredGas returns the gas required to execute the pre-compiled contract.
   662  func (c *bn256PairingIstanbul) RequiredGas(input []byte) uint64 {
   663  	return params.Bn256PairingBaseGasIstanbul + uint64(len(input)/192)*params.Bn256PairingPerPointGasIstanbul
   664  }
   665  
   666  func (c *bn256PairingIstanbul) Run(input []byte) ([]byte, error) {
   667  	return runBn256Pairing(input)
   668  }
   669  
   670  // bn256PairingByzantium implements a pairing pre-compile for the bn256 curve
   671  // conforming to Byzantium consensus rules.
   672  type bn256PairingByzantium struct{}
   673  
   674  // RequiredGas returns the gas required to execute the pre-compiled contract.
   675  func (c *bn256PairingByzantium) RequiredGas(input []byte) uint64 {
   676  	return params.Bn256PairingBaseGasByzantium + uint64(len(input)/192)*params.Bn256PairingPerPointGasByzantium
   677  }
   678  
   679  func (c *bn256PairingByzantium) Run(input []byte) ([]byte, error) {
   680  	return runBn256Pairing(input)
   681  }
   682  
   683  type blake2F struct{}
   684  
   685  func (c *blake2F) RequiredGas(input []byte) uint64 {
   686  	// If the input is malformed, we can't calculate the gas, return 0 and let the
   687  	// actual call choke and fault.
   688  	if len(input) != blake2FInputLength {
   689  		return 0
   690  	}
   691  	return uint64(binary.BigEndian.Uint32(input[0:4]))
   692  }
   693  
   694  const (
   695  	blake2FInputLength        = 213
   696  	blake2FFinalBlockBytes    = byte(1)
   697  	blake2FNonFinalBlockBytes = byte(0)
   698  )
   699  
   700  var (
   701  	errBlake2FInvalidInputLength = errors.New("invalid input length")
   702  	errBlake2FInvalidFinalFlag   = errors.New("invalid final flag")
   703  )
   704  
   705  func (c *blake2F) Run(input []byte) ([]byte, error) {
   706  	// Make sure the input is valid (correct length and final flag)
   707  	if len(input) != blake2FInputLength {
   708  		return nil, errBlake2FInvalidInputLength
   709  	}
   710  	if input[212] != blake2FNonFinalBlockBytes && input[212] != blake2FFinalBlockBytes {
   711  		return nil, errBlake2FInvalidFinalFlag
   712  	}
   713  	// Parse the input into the Blake2b call parameters
   714  	var (
   715  		rounds = binary.BigEndian.Uint32(input[0:4])
   716  		final  = input[212] == blake2FFinalBlockBytes
   717  
   718  		h [8]uint64
   719  		m [16]uint64
   720  		t [2]uint64
   721  	)
   722  	for i := 0; i < 8; i++ {
   723  		offset := 4 + i*8
   724  		h[i] = binary.LittleEndian.Uint64(input[offset : offset+8])
   725  	}
   726  	for i := 0; i < 16; i++ {
   727  		offset := 68 + i*8
   728  		m[i] = binary.LittleEndian.Uint64(input[offset : offset+8])
   729  	}
   730  	t[0] = binary.LittleEndian.Uint64(input[196:204])
   731  	t[1] = binary.LittleEndian.Uint64(input[204:212])
   732  
   733  	// Execute the compression function, extract and return the result
   734  	blake2b.F(&h, m, t, final, rounds)
   735  
   736  	output := make([]byte, 64)
   737  	for i := 0; i < 8; i++ {
   738  		offset := i * 8
   739  		binary.LittleEndian.PutUint64(output[offset:offset+8], h[i])
   740  	}
   741  	return output, nil
   742  }
   743  
   744  var (
   745  	errBLS12381InvalidInputLength          = errors.New("invalid input length")
   746  	errBLS12381InvalidFieldElementTopBytes = errors.New("invalid field element top bytes")
   747  	errBLS12381G1PointSubgroup             = errors.New("g1 point is not on correct subgroup")
   748  	errBLS12381G2PointSubgroup             = errors.New("g2 point is not on correct subgroup")
   749  )
   750  
   751  // bls12381G1Add implements EIP-2537 G1Add precompile.
   752  type bls12381G1Add struct{}
   753  
   754  // RequiredGas returns the gas required to execute the pre-compiled contract.
   755  func (c *bls12381G1Add) RequiredGas(input []byte) uint64 {
   756  	return params.Bls12381G1AddGas
   757  }
   758  
   759  func (c *bls12381G1Add) Run(input []byte) ([]byte, error) {
   760  	// Implements EIP-2537 G1Add precompile.
   761  	// > G1 addition call expects `256` bytes as an input that is interpreted as byte concatenation of two G1 points (`128` bytes each).
   762  	// > Output is an encoding of addition operation result - single G1 point (`128` bytes).
   763  	if len(input) != 256 {
   764  		return nil, errBLS12381InvalidInputLength
   765  	}
   766  	var err error
   767  	var p0, p1 *bls12381.PointG1
   768  
   769  	// Initialize G1
   770  	g := bls12381.NewG1()
   771  
   772  	// Decode G1 point p_0
   773  	if p0, err = g.DecodePoint(input[:128]); err != nil {
   774  		return nil, err
   775  	}
   776  	// Decode G1 point p_1
   777  	if p1, err = g.DecodePoint(input[128:]); err != nil {
   778  		return nil, err
   779  	}
   780  
   781  	// Compute r = p_0 + p_1
   782  	r := g.New()
   783  	g.Add(r, p0, p1)
   784  
   785  	// Encode the G1 point result into 128 bytes
   786  	return g.EncodePoint(r), nil
   787  }
   788  
   789  // bls12381G1Mul implements EIP-2537 G1Mul precompile.
   790  type bls12381G1Mul struct{}
   791  
   792  // RequiredGas returns the gas required to execute the pre-compiled contract.
   793  func (c *bls12381G1Mul) RequiredGas(input []byte) uint64 {
   794  	return params.Bls12381G1MulGas
   795  }
   796  
   797  func (c *bls12381G1Mul) Run(input []byte) ([]byte, error) {
   798  	// Implements EIP-2537 G1Mul precompile.
   799  	// > G1 multiplication call expects `160` bytes as an input that is interpreted as byte concatenation of encoding of G1 point (`128` bytes) and encoding of a scalar value (`32` bytes).
   800  	// > Output is an encoding of multiplication operation result - single G1 point (`128` bytes).
   801  	if len(input) != 160 {
   802  		return nil, errBLS12381InvalidInputLength
   803  	}
   804  	var err error
   805  	var p0 *bls12381.PointG1
   806  
   807  	// Initialize G1
   808  	g := bls12381.NewG1()
   809  
   810  	// Decode G1 point
   811  	if p0, err = g.DecodePoint(input[:128]); err != nil {
   812  		return nil, err
   813  	}
   814  	// Decode scalar value
   815  	e := new(big.Int).SetBytes(input[128:])
   816  
   817  	// Compute r = e * p_0
   818  	r := g.New()
   819  	g.MulScalar(r, p0, e)
   820  
   821  	// Encode the G1 point into 128 bytes
   822  	return g.EncodePoint(r), nil
   823  }
   824  
   825  // bls12381G1MultiExp implements EIP-2537 G1MultiExp precompile.
   826  type bls12381G1MultiExp struct{}
   827  
   828  // RequiredGas returns the gas required to execute the pre-compiled contract.
   829  func (c *bls12381G1MultiExp) RequiredGas(input []byte) uint64 {
   830  	// Calculate G1 point, scalar value pair length
   831  	k := len(input) / 160
   832  	if k == 0 {
   833  		// Return 0 gas for small input length
   834  		return 0
   835  	}
   836  	// Lookup discount value for G1 point, scalar value pair length
   837  	var discount uint64
   838  	if dLen := len(params.Bls12381MultiExpDiscountTable); k < dLen {
   839  		discount = params.Bls12381MultiExpDiscountTable[k-1]
   840  	} else {
   841  		discount = params.Bls12381MultiExpDiscountTable[dLen-1]
   842  	}
   843  	// Calculate gas and return the result
   844  	return (uint64(k) * params.Bls12381G1MulGas * discount) / 1000
   845  }
   846  
   847  func (c *bls12381G1MultiExp) Run(input []byte) ([]byte, error) {
   848  	// Implements EIP-2537 G1MultiExp precompile.
   849  	// G1 multiplication call expects `160*k` bytes as an input that is interpreted as byte concatenation of `k` slices each of them being a byte concatenation of encoding of G1 point (`128` bytes) and encoding of a scalar value (`32` bytes).
   850  	// Output is an encoding of multiexponentiation operation result - single G1 point (`128` bytes).
   851  	k := len(input) / 160
   852  	if len(input) == 0 || len(input)%160 != 0 {
   853  		return nil, errBLS12381InvalidInputLength
   854  	}
   855  	var err error
   856  	points := make([]*bls12381.PointG1, k)
   857  	scalars := make([]*big.Int, k)
   858  
   859  	// Initialize G1
   860  	g := bls12381.NewG1()
   861  
   862  	// Decode point scalar pairs
   863  	for i := 0; i < k; i++ {
   864  		off := 160 * i
   865  		t0, t1, t2 := off, off+128, off+160
   866  		// Decode G1 point
   867  		if points[i], err = g.DecodePoint(input[t0:t1]); err != nil {
   868  			return nil, err
   869  		}
   870  		// Decode scalar value
   871  		scalars[i] = new(big.Int).SetBytes(input[t1:t2])
   872  	}
   873  
   874  	// Compute r = e_0 * p_0 + e_1 * p_1 + ... + e_(k-1) * p_(k-1)
   875  	r := g.New()
   876  	g.MultiExp(r, points, scalars)
   877  
   878  	// Encode the G1 point to 128 bytes
   879  	return g.EncodePoint(r), nil
   880  }
   881  
   882  // bls12381G2Add implements EIP-2537 G2Add precompile.
   883  type bls12381G2Add struct{}
   884  
   885  // RequiredGas returns the gas required to execute the pre-compiled contract.
   886  func (c *bls12381G2Add) RequiredGas(input []byte) uint64 {
   887  	return params.Bls12381G2AddGas
   888  }
   889  
   890  func (c *bls12381G2Add) Run(input []byte) ([]byte, error) {
   891  	// Implements EIP-2537 G2Add precompile.
   892  	// > G2 addition call expects `512` bytes as an input that is interpreted as byte concatenation of two G2 points (`256` bytes each).
   893  	// > Output is an encoding of addition operation result - single G2 point (`256` bytes).
   894  	if len(input) != 512 {
   895  		return nil, errBLS12381InvalidInputLength
   896  	}
   897  	var err error
   898  	var p0, p1 *bls12381.PointG2
   899  
   900  	// Initialize G2
   901  	g := bls12381.NewG2()
   902  	r := g.New()
   903  
   904  	// Decode G2 point p_0
   905  	if p0, err = g.DecodePoint(input[:256]); err != nil {
   906  		return nil, err
   907  	}
   908  	// Decode G2 point p_1
   909  	if p1, err = g.DecodePoint(input[256:]); err != nil {
   910  		return nil, err
   911  	}
   912  
   913  	// Compute r = p_0 + p_1
   914  	g.Add(r, p0, p1)
   915  
   916  	// Encode the G2 point into 256 bytes
   917  	return g.EncodePoint(r), nil
   918  }
   919  
   920  // bls12381G2Mul implements EIP-2537 G2Mul precompile.
   921  type bls12381G2Mul struct{}
   922  
   923  // RequiredGas returns the gas required to execute the pre-compiled contract.
   924  func (c *bls12381G2Mul) RequiredGas(input []byte) uint64 {
   925  	return params.Bls12381G2MulGas
   926  }
   927  
   928  func (c *bls12381G2Mul) Run(input []byte) ([]byte, error) {
   929  	// Implements EIP-2537 G2MUL precompile logic.
   930  	// > G2 multiplication call expects `288` bytes as an input that is interpreted as byte concatenation of encoding of G2 point (`256` bytes) and encoding of a scalar value (`32` bytes).
   931  	// > Output is an encoding of multiplication operation result - single G2 point (`256` bytes).
   932  	if len(input) != 288 {
   933  		return nil, errBLS12381InvalidInputLength
   934  	}
   935  	var err error
   936  	var p0 *bls12381.PointG2
   937  
   938  	// Initialize G2
   939  	g := bls12381.NewG2()
   940  
   941  	// Decode G2 point
   942  	if p0, err = g.DecodePoint(input[:256]); err != nil {
   943  		return nil, err
   944  	}
   945  	// Decode scalar value
   946  	e := new(big.Int).SetBytes(input[256:])
   947  
   948  	// Compute r = e * p_0
   949  	r := g.New()
   950  	g.MulScalar(r, p0, e)
   951  
   952  	// Encode the G2 point into 256 bytes
   953  	return g.EncodePoint(r), nil
   954  }
   955  
   956  // bls12381G2MultiExp implements EIP-2537 G2MultiExp precompile.
   957  type bls12381G2MultiExp struct{}
   958  
   959  // RequiredGas returns the gas required to execute the pre-compiled contract.
   960  func (c *bls12381G2MultiExp) RequiredGas(input []byte) uint64 {
   961  	// Calculate G2 point, scalar value pair length
   962  	k := len(input) / 288
   963  	if k == 0 {
   964  		// Return 0 gas for small input length
   965  		return 0
   966  	}
   967  	// Lookup discount value for G2 point, scalar value pair length
   968  	var discount uint64
   969  	if dLen := len(params.Bls12381MultiExpDiscountTable); k < dLen {
   970  		discount = params.Bls12381MultiExpDiscountTable[k-1]
   971  	} else {
   972  		discount = params.Bls12381MultiExpDiscountTable[dLen-1]
   973  	}
   974  	// Calculate gas and return the result
   975  	return (uint64(k) * params.Bls12381G2MulGas * discount) / 1000
   976  }
   977  
   978  func (c *bls12381G2MultiExp) Run(input []byte) ([]byte, error) {
   979  	// Implements EIP-2537 G2MultiExp precompile logic
   980  	// > G2 multiplication call expects `288*k` bytes as an input that is interpreted as byte concatenation of `k` slices each of them being a byte concatenation of encoding of G2 point (`256` bytes) and encoding of a scalar value (`32` bytes).
   981  	// > Output is an encoding of multiexponentiation operation result - single G2 point (`256` bytes).
   982  	k := len(input) / 288
   983  	if len(input) == 0 || len(input)%288 != 0 {
   984  		return nil, errBLS12381InvalidInputLength
   985  	}
   986  	var err error
   987  	points := make([]*bls12381.PointG2, k)
   988  	scalars := make([]*big.Int, k)
   989  
   990  	// Initialize G2
   991  	g := bls12381.NewG2()
   992  
   993  	// Decode point scalar pairs
   994  	for i := 0; i < k; i++ {
   995  		off := 288 * i
   996  		t0, t1, t2 := off, off+256, off+288
   997  		// Decode G1 point
   998  		if points[i], err = g.DecodePoint(input[t0:t1]); err != nil {
   999  			return nil, err
  1000  		}
  1001  		// Decode scalar value
  1002  		scalars[i] = new(big.Int).SetBytes(input[t1:t2])
  1003  	}
  1004  
  1005  	// Compute r = e_0 * p_0 + e_1 * p_1 + ... + e_(k-1) * p_(k-1)
  1006  	r := g.New()
  1007  	g.MultiExp(r, points, scalars)
  1008  
  1009  	// Encode the G2 point to 256 bytes.
  1010  	return g.EncodePoint(r), nil
  1011  }
  1012  
  1013  // bls12381Pairing implements EIP-2537 Pairing precompile.
  1014  type bls12381Pairing struct{}
  1015  
  1016  // RequiredGas returns the gas required to execute the pre-compiled contract.
  1017  func (c *bls12381Pairing) RequiredGas(input []byte) uint64 {
  1018  	return params.Bls12381PairingBaseGas + uint64(len(input)/384)*params.Bls12381PairingPerPairGas
  1019  }
  1020  
  1021  func (c *bls12381Pairing) Run(input []byte) ([]byte, error) {
  1022  	// Implements EIP-2537 Pairing precompile logic.
  1023  	// > Pairing call expects `384*k` bytes as an inputs that is interpreted as byte concatenation of `k` slices. Each slice has the following structure:
  1024  	// > - `128` bytes of G1 point encoding
  1025  	// > - `256` bytes of G2 point encoding
  1026  	// > Output is a `32` bytes where last single byte is `0x01` if pairing result is equal to multiplicative identity in a pairing target field and `0x00` otherwise
  1027  	// > (which is equivalent of Big Endian encoding of Solidity values `uint256(1)` and `uin256(0)` respectively).
  1028  	k := len(input) / 384
  1029  	if len(input) == 0 || len(input)%384 != 0 {
  1030  		return nil, errBLS12381InvalidInputLength
  1031  	}
  1032  
  1033  	// Initialize BLS12-381 pairing engine
  1034  	e := bls12381.NewPairingEngine()
  1035  	g1, g2 := e.G1, e.G2
  1036  
  1037  	// Decode pairs
  1038  	for i := 0; i < k; i++ {
  1039  		off := 384 * i
  1040  		t0, t1, t2 := off, off+128, off+384
  1041  
  1042  		// Decode G1 point
  1043  		p1, err := g1.DecodePoint(input[t0:t1])
  1044  		if err != nil {
  1045  			return nil, err
  1046  		}
  1047  		// Decode G2 point
  1048  		p2, err := g2.DecodePoint(input[t1:t2])
  1049  		if err != nil {
  1050  			return nil, err
  1051  		}
  1052  
  1053  		// 'point is on curve' check already done,
  1054  		// Here we need to apply subgroup checks.
  1055  		if !g1.InCorrectSubgroup(p1) {
  1056  			return nil, errBLS12381G1PointSubgroup
  1057  		}
  1058  		if !g2.InCorrectSubgroup(p2) {
  1059  			return nil, errBLS12381G2PointSubgroup
  1060  		}
  1061  
  1062  		// Update pairing engine with G1 and G2 points
  1063  		e.AddPair(p1, p2)
  1064  	}
  1065  	// Prepare 32 byte output
  1066  	out := make([]byte, 32)
  1067  
  1068  	// Compute pairing and set the result
  1069  	if e.Check() {
  1070  		out[31] = 1
  1071  	}
  1072  	return out, nil
  1073  }
  1074  
  1075  // decodeBLS12381FieldElement decodes BLS12-381 elliptic curve field element.
  1076  // Removes top 16 bytes of 64 byte input.
  1077  func decodeBLS12381FieldElement(in []byte) ([]byte, error) {
  1078  	if len(in) != 64 {
  1079  		return nil, errors.New("invalid field element length")
  1080  	}
  1081  	// check top bytes
  1082  	for i := 0; i < 16; i++ {
  1083  		if in[i] != byte(0x00) {
  1084  			return nil, errBLS12381InvalidFieldElementTopBytes
  1085  		}
  1086  	}
  1087  	out := make([]byte, 48)
  1088  	copy(out[:], in[16:])
  1089  	return out, nil
  1090  }
  1091  
  1092  // bls12381MapG1 implements EIP-2537 MapG1 precompile.
  1093  type bls12381MapG1 struct{}
  1094  
  1095  // RequiredGas returns the gas required to execute the pre-compiled contract.
  1096  func (c *bls12381MapG1) RequiredGas(input []byte) uint64 {
  1097  	return params.Bls12381MapG1Gas
  1098  }
  1099  
  1100  func (c *bls12381MapG1) Run(input []byte) ([]byte, error) {
  1101  	// Implements EIP-2537 Map_To_G1 precompile.
  1102  	// > Field-to-curve call expects `64` bytes an an input that is interpreted as a an element of the base field.
  1103  	// > Output of this call is `128` bytes and is G1 point following respective encoding rules.
  1104  	if len(input) != 64 {
  1105  		return nil, errBLS12381InvalidInputLength
  1106  	}
  1107  
  1108  	// Decode input field element
  1109  	fe, err := decodeBLS12381FieldElement(input)
  1110  	if err != nil {
  1111  		return nil, err
  1112  	}
  1113  
  1114  	// Initialize G1
  1115  	g := bls12381.NewG1()
  1116  
  1117  	// Compute mapping
  1118  	r, err := g.MapToCurve(fe)
  1119  	if err != nil {
  1120  		return nil, err
  1121  	}
  1122  
  1123  	// Encode the G1 point to 128 bytes
  1124  	return g.EncodePoint(r), nil
  1125  }
  1126  
  1127  // bls12381MapG2 implements EIP-2537 MapG2 precompile.
  1128  type bls12381MapG2 struct{}
  1129  
  1130  // RequiredGas returns the gas required to execute the pre-compiled contract.
  1131  func (c *bls12381MapG2) RequiredGas(input []byte) uint64 {
  1132  	return params.Bls12381MapG2Gas
  1133  }
  1134  
  1135  func (c *bls12381MapG2) Run(input []byte) ([]byte, error) {
  1136  	// Implements EIP-2537 Map_FP2_TO_G2 precompile logic.
  1137  	// > Field-to-curve call expects `128` bytes an an input that is interpreted as a an element of the quadratic extension field.
  1138  	// > Output of this call is `256` bytes and is G2 point following respective encoding rules.
  1139  	if len(input) != 128 {
  1140  		return nil, errBLS12381InvalidInputLength
  1141  	}
  1142  
  1143  	// Decode input field element
  1144  	fe := make([]byte, 96)
  1145  	c0, err := decodeBLS12381FieldElement(input[:64])
  1146  	if err != nil {
  1147  		return nil, err
  1148  	}
  1149  	copy(fe[48:], c0)
  1150  	c1, err := decodeBLS12381FieldElement(input[64:])
  1151  	if err != nil {
  1152  		return nil, err
  1153  	}
  1154  	copy(fe[:48], c1)
  1155  
  1156  	// Initialize G2
  1157  	g := bls12381.NewG2()
  1158  
  1159  	// Compute mapping
  1160  	r, err := g.MapToCurve(fe)
  1161  	if err != nil {
  1162  		return nil, err
  1163  	}
  1164  
  1165  	// Encode the G2 point to 256 bytes
  1166  	return g.EncodePoint(r), nil
  1167  }
  1168  
  1169  // kzgPointEvaluation implements the EIP-4844 point evaluation precompile.
  1170  type kzgPointEvaluation struct{}
  1171  
  1172  // RequiredGas estimates the gas required for running the point evaluation precompile.
  1173  func (b *kzgPointEvaluation) RequiredGas(input []byte) uint64 {
  1174  	return params.BlobTxPointEvaluationPrecompileGas
  1175  }
  1176  
  1177  const (
  1178  	blobVerifyInputLength           = 192  // Max input length for the point evaluation precompile.
  1179  	blobCommitmentVersionKZG  uint8 = 0x01 // Version byte for the point evaluation precompile.
  1180  	blobPrecompileReturnValue       = "000000000000000000000000000000000000000000000000000000000000100073eda753299d7d483339d80809a1d80553bda402fffe5bfeffffffff00000001"
  1181  )
  1182  
  1183  var (
  1184  	errBlobVerifyInvalidInputLength = errors.New("invalid input length")
  1185  	errBlobVerifyMismatchedVersion  = errors.New("mismatched versioned hash")
  1186  	errBlobVerifyKZGProof           = errors.New("error verifying kzg proof")
  1187  )
  1188  
  1189  // Run executes the point evaluation precompile.
  1190  func (b *kzgPointEvaluation) Run(input []byte) ([]byte, error) {
  1191  	if len(input) != blobVerifyInputLength {
  1192  		return nil, errBlobVerifyInvalidInputLength
  1193  	}
  1194  	// versioned hash: first 32 bytes
  1195  	var versionedHash common.Hash
  1196  	copy(versionedHash[:], input[:])
  1197  
  1198  	var (
  1199  		point kzg4844.Point
  1200  		claim kzg4844.Claim
  1201  	)
  1202  	// Evaluation point: next 32 bytes
  1203  	copy(point[:], input[32:])
  1204  	// Expected output: next 32 bytes
  1205  	copy(claim[:], input[64:])
  1206  
  1207  	// input kzg point: next 48 bytes
  1208  	var commitment kzg4844.Commitment
  1209  	copy(commitment[:], input[96:])
  1210  	if kZGToVersionedHash(commitment) != versionedHash {
  1211  		return nil, errBlobVerifyMismatchedVersion
  1212  	}
  1213  
  1214  	// Proof: next 48 bytes
  1215  	var proof kzg4844.Proof
  1216  	copy(proof[:], input[144:])
  1217  
  1218  	if err := kzg4844.VerifyProof(commitment, point, claim, proof); err != nil {
  1219  		return nil, fmt.Errorf("%w: %v", errBlobVerifyKZGProof, err)
  1220  	}
  1221  
  1222  	return common.Hex2Bytes(blobPrecompileReturnValue), nil
  1223  }
  1224  
  1225  // kZGToVersionedHash implements kzg_to_versioned_hash from EIP-4844
  1226  func kZGToVersionedHash(kzg kzg4844.Commitment) common.Hash {
  1227  	h := sha256.Sum256(kzg[:])
  1228  	h[0] = blobCommitmentVersionKZG
  1229  
  1230  	return h
  1231  }