github.com/tirogen/go-ethereum@v1.10.12-0.20221226051715-250cfede41b6/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  	"crypto/sha256"
    21  	"encoding/binary"
    22  	"errors"
    23  	"math/big"
    24  
    25  	big2 "github.com/holiman/big"
    26  	"github.com/tirogen/go-ethereum/common"
    27  	"github.com/tirogen/go-ethereum/common/math"
    28  	"github.com/tirogen/go-ethereum/crypto"
    29  	"github.com/tirogen/go-ethereum/crypto/blake2b"
    30  	"github.com/tirogen/go-ethereum/crypto/bls12381"
    31  	"github.com/tirogen/go-ethereum/crypto/bn256"
    32  	"github.com/tirogen/go-ethereum/params"
    33  	"golang.org/x/crypto/ripemd160"
    34  )
    35  
    36  // PrecompiledContract is the basic interface for native Go contracts. The implementation
    37  // requires a deterministic gas count based on the input size of the Run method of the
    38  // contract.
    39  type PrecompiledContract interface {
    40  	RequiredGas(input []byte) uint64  // RequiredPrice calculates the contract gas use
    41  	Run(input []byte) ([]byte, error) // Run runs the precompiled contract
    42  }
    43  
    44  // PrecompiledContractsHomestead contains the default set of pre-compiled Ethereum
    45  // contracts used in the Frontier and Homestead releases.
    46  var PrecompiledContractsHomestead = map[common.Address]PrecompiledContract{
    47  	common.BytesToAddress([]byte{1}): &ecrecover{},
    48  	common.BytesToAddress([]byte{2}): &sha256hash{},
    49  	common.BytesToAddress([]byte{3}): &ripemd160hash{},
    50  	common.BytesToAddress([]byte{4}): &dataCopy{},
    51  }
    52  
    53  // PrecompiledContractsByzantium contains the default set of pre-compiled Ethereum
    54  // contracts used in the Byzantium release.
    55  var PrecompiledContractsByzantium = map[common.Address]PrecompiledContract{
    56  	common.BytesToAddress([]byte{1}): &ecrecover{},
    57  	common.BytesToAddress([]byte{2}): &sha256hash{},
    58  	common.BytesToAddress([]byte{3}): &ripemd160hash{},
    59  	common.BytesToAddress([]byte{4}): &dataCopy{},
    60  	common.BytesToAddress([]byte{5}): &bigModExp{eip2565: false},
    61  	common.BytesToAddress([]byte{6}): &bn256AddByzantium{},
    62  	common.BytesToAddress([]byte{7}): &bn256ScalarMulByzantium{},
    63  	common.BytesToAddress([]byte{8}): &bn256PairingByzantium{},
    64  }
    65  
    66  // PrecompiledContractsIstanbul contains the default set of pre-compiled Ethereum
    67  // contracts used in the Istanbul release.
    68  var PrecompiledContractsIstanbul = map[common.Address]PrecompiledContract{
    69  	common.BytesToAddress([]byte{1}): &ecrecover{},
    70  	common.BytesToAddress([]byte{2}): &sha256hash{},
    71  	common.BytesToAddress([]byte{3}): &ripemd160hash{},
    72  	common.BytesToAddress([]byte{4}): &dataCopy{},
    73  	common.BytesToAddress([]byte{5}): &bigModExp{eip2565: false},
    74  	common.BytesToAddress([]byte{6}): &bn256AddIstanbul{},
    75  	common.BytesToAddress([]byte{7}): &bn256ScalarMulIstanbul{},
    76  	common.BytesToAddress([]byte{8}): &bn256PairingIstanbul{},
    77  	common.BytesToAddress([]byte{9}): &blake2F{},
    78  }
    79  
    80  // PrecompiledContractsBerlin contains the default set of pre-compiled Ethereum
    81  // contracts used in the Berlin release.
    82  var PrecompiledContractsBerlin = map[common.Address]PrecompiledContract{
    83  	common.BytesToAddress([]byte{1}): &ecrecover{},
    84  	common.BytesToAddress([]byte{2}): &sha256hash{},
    85  	common.BytesToAddress([]byte{3}): &ripemd160hash{},
    86  	common.BytesToAddress([]byte{4}): &dataCopy{},
    87  	common.BytesToAddress([]byte{5}): &bigModExp{eip2565: true},
    88  	common.BytesToAddress([]byte{6}): &bn256AddIstanbul{},
    89  	common.BytesToAddress([]byte{7}): &bn256ScalarMulIstanbul{},
    90  	common.BytesToAddress([]byte{8}): &bn256PairingIstanbul{},
    91  	common.BytesToAddress([]byte{9}): &blake2F{},
    92  }
    93  
    94  // PrecompiledContractsBLS contains the set of pre-compiled Ethereum
    95  // contracts specified in EIP-2537. These are exported for testing purposes.
    96  var PrecompiledContractsBLS = map[common.Address]PrecompiledContract{
    97  	common.BytesToAddress([]byte{10}): &bls12381G1Add{},
    98  	common.BytesToAddress([]byte{11}): &bls12381G1Mul{},
    99  	common.BytesToAddress([]byte{12}): &bls12381G1MultiExp{},
   100  	common.BytesToAddress([]byte{13}): &bls12381G2Add{},
   101  	common.BytesToAddress([]byte{14}): &bls12381G2Mul{},
   102  	common.BytesToAddress([]byte{15}): &bls12381G2MultiExp{},
   103  	common.BytesToAddress([]byte{16}): &bls12381Pairing{},
   104  	common.BytesToAddress([]byte{17}): &bls12381MapG1{},
   105  	common.BytesToAddress([]byte{18}): &bls12381MapG2{},
   106  }
   107  
   108  var (
   109  	PrecompiledAddressesBerlin    []common.Address
   110  	PrecompiledAddressesIstanbul  []common.Address
   111  	PrecompiledAddressesByzantium []common.Address
   112  	PrecompiledAddressesHomestead []common.Address
   113  )
   114  
   115  func init() {
   116  	for k := range PrecompiledContractsHomestead {
   117  		PrecompiledAddressesHomestead = append(PrecompiledAddressesHomestead, k)
   118  	}
   119  	for k := range PrecompiledContractsByzantium {
   120  		PrecompiledAddressesByzantium = append(PrecompiledAddressesByzantium, k)
   121  	}
   122  	for k := range PrecompiledContractsIstanbul {
   123  		PrecompiledAddressesIstanbul = append(PrecompiledAddressesIstanbul, k)
   124  	}
   125  	for k := range PrecompiledContractsBerlin {
   126  		PrecompiledAddressesBerlin = append(PrecompiledAddressesBerlin, k)
   127  	}
   128  }
   129  
   130  // ActivePrecompiles returns the precompiles enabled with the current configuration.
   131  func ActivePrecompiles(rules params.Rules) []common.Address {
   132  	switch {
   133  	case rules.IsBerlin:
   134  		return PrecompiledAddressesBerlin
   135  	case rules.IsIstanbul:
   136  		return PrecompiledAddressesIstanbul
   137  	case rules.IsByzantium:
   138  		return PrecompiledAddressesByzantium
   139  	default:
   140  		return PrecompiledAddressesHomestead
   141  	}
   142  }
   143  
   144  // RunPrecompiledContract runs and evaluates the output of a precompiled contract.
   145  // It returns
   146  // - the returned bytes,
   147  // - the _remaining_ gas,
   148  // - any error that occurred
   149  func RunPrecompiledContract(p PrecompiledContract, input []byte, suppliedGas uint64) (ret []byte, remainingGas uint64, err error) {
   150  	gasCost := p.RequiredGas(input)
   151  	if suppliedGas < gasCost {
   152  		return nil, 0, ErrOutOfGas
   153  	}
   154  	suppliedGas -= gasCost
   155  	output, err := p.Run(input)
   156  	return output, suppliedGas, err
   157  }
   158  
   159  // ECRECOVER implemented as a native contract.
   160  type ecrecover struct{}
   161  
   162  func (c *ecrecover) RequiredGas(input []byte) uint64 {
   163  	return params.EcrecoverGas
   164  }
   165  
   166  func (c *ecrecover) Run(input []byte) ([]byte, error) {
   167  	const ecRecoverInputLength = 128
   168  
   169  	input = common.RightPadBytes(input, ecRecoverInputLength)
   170  	// "input" is (hash, v, r, s), each 32 bytes
   171  	// but for ecrecover we want (r, s, v)
   172  
   173  	r := new(big.Int).SetBytes(input[64:96])
   174  	s := new(big.Int).SetBytes(input[96:128])
   175  	v := input[63] - 27
   176  
   177  	// tighter sig s values input homestead only apply to tx sigs
   178  	if !allZero(input[32:63]) || !crypto.ValidateSignatureValues(v, r, s, false) {
   179  		return nil, nil
   180  	}
   181  	// We must make sure not to modify the 'input', so placing the 'v' along with
   182  	// the signature needs to be done on a new allocation
   183  	sig := make([]byte, 65)
   184  	copy(sig, input[64:128])
   185  	sig[64] = v
   186  	// v needs to be at the end for libsecp256k1
   187  	pubKey, err := crypto.Ecrecover(input[:32], sig)
   188  	// make sure the public key is a valid one
   189  	if err != nil {
   190  		return nil, nil
   191  	}
   192  
   193  	// the first byte of pubkey is bitcoin heritage
   194  	return common.LeftPadBytes(crypto.Keccak256(pubKey[1:])[12:], 32), nil
   195  }
   196  
   197  // SHA256 implemented as a native contract.
   198  type sha256hash struct{}
   199  
   200  // RequiredGas returns the gas required to execute the pre-compiled contract.
   201  //
   202  // This method does not require any overflow checking as the input size gas costs
   203  // required for anything significant is so high it's impossible to pay for.
   204  func (c *sha256hash) RequiredGas(input []byte) uint64 {
   205  	return uint64(len(input)+31)/32*params.Sha256PerWordGas + params.Sha256BaseGas
   206  }
   207  func (c *sha256hash) Run(input []byte) ([]byte, error) {
   208  	h := sha256.Sum256(input)
   209  	return h[:], nil
   210  }
   211  
   212  // RIPEMD160 implemented as a native contract.
   213  type ripemd160hash struct{}
   214  
   215  // RequiredGas returns the gas required to execute the pre-compiled contract.
   216  //
   217  // This method does not require any overflow checking as the input size gas costs
   218  // required for anything significant is so high it's impossible to pay for.
   219  func (c *ripemd160hash) RequiredGas(input []byte) uint64 {
   220  	return uint64(len(input)+31)/32*params.Ripemd160PerWordGas + params.Ripemd160BaseGas
   221  }
   222  func (c *ripemd160hash) Run(input []byte) ([]byte, error) {
   223  	ripemd := ripemd160.New()
   224  	ripemd.Write(input)
   225  	return common.LeftPadBytes(ripemd.Sum(nil), 32), nil
   226  }
   227  
   228  // data copy implemented as a native contract.
   229  type dataCopy struct{}
   230  
   231  // RequiredGas returns the gas required to execute the pre-compiled contract.
   232  //
   233  // This method does not require any overflow checking as the input size gas costs
   234  // required for anything significant is so high it's impossible to pay for.
   235  func (c *dataCopy) RequiredGas(input []byte) uint64 {
   236  	return uint64(len(input)+31)/32*params.IdentityPerWordGas + params.IdentityBaseGas
   237  }
   238  func (c *dataCopy) Run(in []byte) ([]byte, error) {
   239  	return common.CopyBytes(in), nil
   240  }
   241  
   242  // bigModExp implements a native big integer exponential modular operation.
   243  type bigModExp struct {
   244  	eip2565 bool
   245  }
   246  
   247  var (
   248  	big0      = big.NewInt(0)
   249  	big1      = big.NewInt(1)
   250  	big3      = big.NewInt(3)
   251  	big4      = big.NewInt(4)
   252  	big7      = big.NewInt(7)
   253  	big8      = big.NewInt(8)
   254  	big16     = big.NewInt(16)
   255  	big20     = big.NewInt(20)
   256  	big32     = big.NewInt(32)
   257  	big64     = big.NewInt(64)
   258  	big96     = big.NewInt(96)
   259  	big480    = big.NewInt(480)
   260  	big1024   = big.NewInt(1024)
   261  	big3072   = big.NewInt(3072)
   262  	big199680 = big.NewInt(199680)
   263  )
   264  
   265  // modexpMultComplexity implements bigModexp multComplexity formula, as defined in EIP-198
   266  //
   267  //	def mult_complexity(x):
   268  //		if x <= 64: return x ** 2
   269  //		elif x <= 1024: return x ** 2 // 4 + 96 * x - 3072
   270  //		else: return x ** 2 // 16 + 480 * x - 199680
   271  //
   272  // where is x is max(length_of_MODULUS, length_of_BASE)
   273  func modexpMultComplexity(x *big.Int) *big.Int {
   274  	switch {
   275  	case x.Cmp(big64) <= 0:
   276  		x.Mul(x, x) // x ** 2
   277  	case x.Cmp(big1024) <= 0:
   278  		// (x ** 2 // 4 ) + ( 96 * x - 3072)
   279  		x = new(big.Int).Add(
   280  			new(big.Int).Div(new(big.Int).Mul(x, x), big4),
   281  			new(big.Int).Sub(new(big.Int).Mul(big96, x), big3072),
   282  		)
   283  	default:
   284  		// (x ** 2 // 16) + (480 * x - 199680)
   285  		x = new(big.Int).Add(
   286  			new(big.Int).Div(new(big.Int).Mul(x, x), big16),
   287  			new(big.Int).Sub(new(big.Int).Mul(big480, x), big199680),
   288  		)
   289  	}
   290  	return x
   291  }
   292  
   293  // RequiredGas returns the gas required to execute the pre-compiled contract.
   294  func (c *bigModExp) RequiredGas(input []byte) uint64 {
   295  	var (
   296  		baseLen = new(big.Int).SetBytes(getData(input, 0, 32))
   297  		expLen  = new(big.Int).SetBytes(getData(input, 32, 32))
   298  		modLen  = new(big.Int).SetBytes(getData(input, 64, 32))
   299  	)
   300  	if len(input) > 96 {
   301  		input = input[96:]
   302  	} else {
   303  		input = input[:0]
   304  	}
   305  	// Retrieve the head 32 bytes of exp for the adjusted exponent length
   306  	var expHead *big.Int
   307  	if big.NewInt(int64(len(input))).Cmp(baseLen) <= 0 {
   308  		expHead = new(big.Int)
   309  	} else {
   310  		if expLen.Cmp(big32) > 0 {
   311  			expHead = new(big.Int).SetBytes(getData(input, baseLen.Uint64(), 32))
   312  		} else {
   313  			expHead = new(big.Int).SetBytes(getData(input, baseLen.Uint64(), expLen.Uint64()))
   314  		}
   315  	}
   316  	// Calculate the adjusted exponent length
   317  	var msb int
   318  	if bitlen := expHead.BitLen(); bitlen > 0 {
   319  		msb = bitlen - 1
   320  	}
   321  	adjExpLen := new(big.Int)
   322  	if expLen.Cmp(big32) > 0 {
   323  		adjExpLen.Sub(expLen, big32)
   324  		adjExpLen.Mul(big8, adjExpLen)
   325  	}
   326  	adjExpLen.Add(adjExpLen, big.NewInt(int64(msb)))
   327  	// Calculate the gas cost of the operation
   328  	gas := new(big.Int).Set(math.BigMax(modLen, baseLen))
   329  	if c.eip2565 {
   330  		// EIP-2565 has three changes
   331  		// 1. Different multComplexity (inlined here)
   332  		// in EIP-2565 (https://eips.ethereum.org/EIPS/eip-2565):
   333  		//
   334  		// def mult_complexity(x):
   335  		//    ceiling(x/8)^2
   336  		//
   337  		//where is x is max(length_of_MODULUS, length_of_BASE)
   338  		gas = gas.Add(gas, big7)
   339  		gas = gas.Div(gas, big8)
   340  		gas.Mul(gas, gas)
   341  
   342  		gas.Mul(gas, math.BigMax(adjExpLen, big1))
   343  		// 2. Different divisor (`GQUADDIVISOR`) (3)
   344  		gas.Div(gas, big3)
   345  		if gas.BitLen() > 64 {
   346  			return math.MaxUint64
   347  		}
   348  		// 3. Minimum price of 200 gas
   349  		if gas.Uint64() < 200 {
   350  			return 200
   351  		}
   352  		return gas.Uint64()
   353  	}
   354  	gas = modexpMultComplexity(gas)
   355  	gas.Mul(gas, math.BigMax(adjExpLen, big1))
   356  	gas.Div(gas, big20)
   357  
   358  	if gas.BitLen() > 64 {
   359  		return math.MaxUint64
   360  	}
   361  	return gas.Uint64()
   362  }
   363  
   364  func (c *bigModExp) Run(input []byte) ([]byte, error) {
   365  	var (
   366  		baseLen = new(big.Int).SetBytes(getData(input, 0, 32)).Uint64()
   367  		expLen  = new(big.Int).SetBytes(getData(input, 32, 32)).Uint64()
   368  		modLen  = new(big.Int).SetBytes(getData(input, 64, 32)).Uint64()
   369  	)
   370  	if len(input) > 96 {
   371  		input = input[96:]
   372  	} else {
   373  		input = input[:0]
   374  	}
   375  	// Handle a special case when both the base and mod length is zero
   376  	if baseLen == 0 && modLen == 0 {
   377  		return []byte{}, nil
   378  	}
   379  	// Retrieve the operands and execute the exponentiation
   380  	var (
   381  		base = new(big2.Int).SetBytes(getData(input, 0, baseLen))
   382  		exp  = new(big2.Int).SetBytes(getData(input, baseLen, expLen))
   383  		mod  = new(big2.Int).SetBytes(getData(input, baseLen+expLen, modLen))
   384  		v    []byte
   385  	)
   386  	switch {
   387  	case mod.BitLen() == 0:
   388  		// Modulo 0 is undefined, return zero
   389  		return common.LeftPadBytes([]byte{}, int(modLen)), nil
   390  	case base.BitLen() == 1: // a bit length of 1 means it's 1 (or -1).
   391  		//If base == 1, then we can just return base % mod (if mod >= 1, which it is)
   392  		v = base.Mod(base, mod).Bytes()
   393  	default:
   394  		v = base.Exp(base, exp, mod).Bytes()
   395  	}
   396  	return common.LeftPadBytes(v, int(modLen)), nil
   397  }
   398  
   399  // newCurvePoint unmarshals a binary blob into a bn256 elliptic curve point,
   400  // returning it, or an error if the point is invalid.
   401  func newCurvePoint(blob []byte) (*bn256.G1, error) {
   402  	p := new(bn256.G1)
   403  	if _, err := p.Unmarshal(blob); err != nil {
   404  		return nil, err
   405  	}
   406  	return p, nil
   407  }
   408  
   409  // newTwistPoint unmarshals a binary blob into a bn256 elliptic curve point,
   410  // returning it, or an error if the point is invalid.
   411  func newTwistPoint(blob []byte) (*bn256.G2, error) {
   412  	p := new(bn256.G2)
   413  	if _, err := p.Unmarshal(blob); err != nil {
   414  		return nil, err
   415  	}
   416  	return p, nil
   417  }
   418  
   419  // runBn256Add implements the Bn256Add precompile, referenced by both
   420  // Byzantium and Istanbul operations.
   421  func runBn256Add(input []byte) ([]byte, error) {
   422  	x, err := newCurvePoint(getData(input, 0, 64))
   423  	if err != nil {
   424  		return nil, err
   425  	}
   426  	y, err := newCurvePoint(getData(input, 64, 64))
   427  	if err != nil {
   428  		return nil, err
   429  	}
   430  	res := new(bn256.G1)
   431  	res.Add(x, y)
   432  	return res.Marshal(), nil
   433  }
   434  
   435  // bn256Add implements a native elliptic curve point addition conforming to
   436  // Istanbul consensus rules.
   437  type bn256AddIstanbul struct{}
   438  
   439  // RequiredGas returns the gas required to execute the pre-compiled contract.
   440  func (c *bn256AddIstanbul) RequiredGas(input []byte) uint64 {
   441  	return params.Bn256AddGasIstanbul
   442  }
   443  
   444  func (c *bn256AddIstanbul) Run(input []byte) ([]byte, error) {
   445  	return runBn256Add(input)
   446  }
   447  
   448  // bn256AddByzantium implements a native elliptic curve point addition
   449  // conforming to Byzantium consensus rules.
   450  type bn256AddByzantium struct{}
   451  
   452  // RequiredGas returns the gas required to execute the pre-compiled contract.
   453  func (c *bn256AddByzantium) RequiredGas(input []byte) uint64 {
   454  	return params.Bn256AddGasByzantium
   455  }
   456  
   457  func (c *bn256AddByzantium) Run(input []byte) ([]byte, error) {
   458  	return runBn256Add(input)
   459  }
   460  
   461  // runBn256ScalarMul implements the Bn256ScalarMul precompile, referenced by
   462  // both Byzantium and Istanbul operations.
   463  func runBn256ScalarMul(input []byte) ([]byte, error) {
   464  	p, err := newCurvePoint(getData(input, 0, 64))
   465  	if err != nil {
   466  		return nil, err
   467  	}
   468  	res := new(bn256.G1)
   469  	res.ScalarMult(p, new(big.Int).SetBytes(getData(input, 64, 32)))
   470  	return res.Marshal(), nil
   471  }
   472  
   473  // bn256ScalarMulIstanbul implements a native elliptic curve scalar
   474  // multiplication conforming to Istanbul consensus rules.
   475  type bn256ScalarMulIstanbul struct{}
   476  
   477  // RequiredGas returns the gas required to execute the pre-compiled contract.
   478  func (c *bn256ScalarMulIstanbul) RequiredGas(input []byte) uint64 {
   479  	return params.Bn256ScalarMulGasIstanbul
   480  }
   481  
   482  func (c *bn256ScalarMulIstanbul) Run(input []byte) ([]byte, error) {
   483  	return runBn256ScalarMul(input)
   484  }
   485  
   486  // bn256ScalarMulByzantium implements a native elliptic curve scalar
   487  // multiplication conforming to Byzantium consensus rules.
   488  type bn256ScalarMulByzantium struct{}
   489  
   490  // RequiredGas returns the gas required to execute the pre-compiled contract.
   491  func (c *bn256ScalarMulByzantium) RequiredGas(input []byte) uint64 {
   492  	return params.Bn256ScalarMulGasByzantium
   493  }
   494  
   495  func (c *bn256ScalarMulByzantium) Run(input []byte) ([]byte, error) {
   496  	return runBn256ScalarMul(input)
   497  }
   498  
   499  var (
   500  	// true32Byte is returned if the bn256 pairing check succeeds.
   501  	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}
   502  
   503  	// false32Byte is returned if the bn256 pairing check fails.
   504  	false32Byte = make([]byte, 32)
   505  
   506  	// errBadPairingInput is returned if the bn256 pairing input is invalid.
   507  	errBadPairingInput = errors.New("bad elliptic curve pairing size")
   508  )
   509  
   510  // runBn256Pairing implements the Bn256Pairing precompile, referenced by both
   511  // Byzantium and Istanbul operations.
   512  func runBn256Pairing(input []byte) ([]byte, error) {
   513  	// Handle some corner cases cheaply
   514  	if len(input)%192 > 0 {
   515  		return nil, errBadPairingInput
   516  	}
   517  	// Convert the input into a set of coordinates
   518  	var (
   519  		cs []*bn256.G1
   520  		ts []*bn256.G2
   521  	)
   522  	for i := 0; i < len(input); i += 192 {
   523  		c, err := newCurvePoint(input[i : i+64])
   524  		if err != nil {
   525  			return nil, err
   526  		}
   527  		t, err := newTwistPoint(input[i+64 : i+192])
   528  		if err != nil {
   529  			return nil, err
   530  		}
   531  		cs = append(cs, c)
   532  		ts = append(ts, t)
   533  	}
   534  	// Execute the pairing checks and return the results
   535  	if bn256.PairingCheck(cs, ts) {
   536  		return true32Byte, nil
   537  	}
   538  	return false32Byte, nil
   539  }
   540  
   541  // bn256PairingIstanbul implements a pairing pre-compile for the bn256 curve
   542  // conforming to Istanbul consensus rules.
   543  type bn256PairingIstanbul struct{}
   544  
   545  // RequiredGas returns the gas required to execute the pre-compiled contract.
   546  func (c *bn256PairingIstanbul) RequiredGas(input []byte) uint64 {
   547  	return params.Bn256PairingBaseGasIstanbul + uint64(len(input)/192)*params.Bn256PairingPerPointGasIstanbul
   548  }
   549  
   550  func (c *bn256PairingIstanbul) Run(input []byte) ([]byte, error) {
   551  	return runBn256Pairing(input)
   552  }
   553  
   554  // bn256PairingByzantium implements a pairing pre-compile for the bn256 curve
   555  // conforming to Byzantium consensus rules.
   556  type bn256PairingByzantium struct{}
   557  
   558  // RequiredGas returns the gas required to execute the pre-compiled contract.
   559  func (c *bn256PairingByzantium) RequiredGas(input []byte) uint64 {
   560  	return params.Bn256PairingBaseGasByzantium + uint64(len(input)/192)*params.Bn256PairingPerPointGasByzantium
   561  }
   562  
   563  func (c *bn256PairingByzantium) Run(input []byte) ([]byte, error) {
   564  	return runBn256Pairing(input)
   565  }
   566  
   567  type blake2F struct{}
   568  
   569  func (c *blake2F) RequiredGas(input []byte) uint64 {
   570  	// If the input is malformed, we can't calculate the gas, return 0 and let the
   571  	// actual call choke and fault.
   572  	if len(input) != blake2FInputLength {
   573  		return 0
   574  	}
   575  	return uint64(binary.BigEndian.Uint32(input[0:4]))
   576  }
   577  
   578  const (
   579  	blake2FInputLength        = 213
   580  	blake2FFinalBlockBytes    = byte(1)
   581  	blake2FNonFinalBlockBytes = byte(0)
   582  )
   583  
   584  var (
   585  	errBlake2FInvalidInputLength = errors.New("invalid input length")
   586  	errBlake2FInvalidFinalFlag   = errors.New("invalid final flag")
   587  )
   588  
   589  func (c *blake2F) Run(input []byte) ([]byte, error) {
   590  	// Make sure the input is valid (correct length and final flag)
   591  	if len(input) != blake2FInputLength {
   592  		return nil, errBlake2FInvalidInputLength
   593  	}
   594  	if input[212] != blake2FNonFinalBlockBytes && input[212] != blake2FFinalBlockBytes {
   595  		return nil, errBlake2FInvalidFinalFlag
   596  	}
   597  	// Parse the input into the Blake2b call parameters
   598  	var (
   599  		rounds = binary.BigEndian.Uint32(input[0:4])
   600  		final  = input[212] == blake2FFinalBlockBytes
   601  
   602  		h [8]uint64
   603  		m [16]uint64
   604  		t [2]uint64
   605  	)
   606  	for i := 0; i < 8; i++ {
   607  		offset := 4 + i*8
   608  		h[i] = binary.LittleEndian.Uint64(input[offset : offset+8])
   609  	}
   610  	for i := 0; i < 16; i++ {
   611  		offset := 68 + i*8
   612  		m[i] = binary.LittleEndian.Uint64(input[offset : offset+8])
   613  	}
   614  	t[0] = binary.LittleEndian.Uint64(input[196:204])
   615  	t[1] = binary.LittleEndian.Uint64(input[204:212])
   616  
   617  	// Execute the compression function, extract and return the result
   618  	blake2b.F(&h, m, t, final, rounds)
   619  
   620  	output := make([]byte, 64)
   621  	for i := 0; i < 8; i++ {
   622  		offset := i * 8
   623  		binary.LittleEndian.PutUint64(output[offset:offset+8], h[i])
   624  	}
   625  	return output, nil
   626  }
   627  
   628  var (
   629  	errBLS12381InvalidInputLength          = errors.New("invalid input length")
   630  	errBLS12381InvalidFieldElementTopBytes = errors.New("invalid field element top bytes")
   631  	errBLS12381G1PointSubgroup             = errors.New("g1 point is not on correct subgroup")
   632  	errBLS12381G2PointSubgroup             = errors.New("g2 point is not on correct subgroup")
   633  )
   634  
   635  // bls12381G1Add implements EIP-2537 G1Add precompile.
   636  type bls12381G1Add struct{}
   637  
   638  // RequiredGas returns the gas required to execute the pre-compiled contract.
   639  func (c *bls12381G1Add) RequiredGas(input []byte) uint64 {
   640  	return params.Bls12381G1AddGas
   641  }
   642  
   643  func (c *bls12381G1Add) Run(input []byte) ([]byte, error) {
   644  	// Implements EIP-2537 G1Add precompile.
   645  	// > G1 addition call expects `256` bytes as an input that is interpreted as byte concatenation of two G1 points (`128` bytes each).
   646  	// > Output is an encoding of addition operation result - single G1 point (`128` bytes).
   647  	if len(input) != 256 {
   648  		return nil, errBLS12381InvalidInputLength
   649  	}
   650  	var err error
   651  	var p0, p1 *bls12381.PointG1
   652  
   653  	// Initialize G1
   654  	g := bls12381.NewG1()
   655  
   656  	// Decode G1 point p_0
   657  	if p0, err = g.DecodePoint(input[:128]); err != nil {
   658  		return nil, err
   659  	}
   660  	// Decode G1 point p_1
   661  	if p1, err = g.DecodePoint(input[128:]); err != nil {
   662  		return nil, err
   663  	}
   664  
   665  	// Compute r = p_0 + p_1
   666  	r := g.New()
   667  	g.Add(r, p0, p1)
   668  
   669  	// Encode the G1 point result into 128 bytes
   670  	return g.EncodePoint(r), nil
   671  }
   672  
   673  // bls12381G1Mul implements EIP-2537 G1Mul precompile.
   674  type bls12381G1Mul struct{}
   675  
   676  // RequiredGas returns the gas required to execute the pre-compiled contract.
   677  func (c *bls12381G1Mul) RequiredGas(input []byte) uint64 {
   678  	return params.Bls12381G1MulGas
   679  }
   680  
   681  func (c *bls12381G1Mul) Run(input []byte) ([]byte, error) {
   682  	// Implements EIP-2537 G1Mul precompile.
   683  	// > 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).
   684  	// > Output is an encoding of multiplication operation result - single G1 point (`128` bytes).
   685  	if len(input) != 160 {
   686  		return nil, errBLS12381InvalidInputLength
   687  	}
   688  	var err error
   689  	var p0 *bls12381.PointG1
   690  
   691  	// Initialize G1
   692  	g := bls12381.NewG1()
   693  
   694  	// Decode G1 point
   695  	if p0, err = g.DecodePoint(input[:128]); err != nil {
   696  		return nil, err
   697  	}
   698  	// Decode scalar value
   699  	e := new(big.Int).SetBytes(input[128:])
   700  
   701  	// Compute r = e * p_0
   702  	r := g.New()
   703  	g.MulScalar(r, p0, e)
   704  
   705  	// Encode the G1 point into 128 bytes
   706  	return g.EncodePoint(r), nil
   707  }
   708  
   709  // bls12381G1MultiExp implements EIP-2537 G1MultiExp precompile.
   710  type bls12381G1MultiExp struct{}
   711  
   712  // RequiredGas returns the gas required to execute the pre-compiled contract.
   713  func (c *bls12381G1MultiExp) RequiredGas(input []byte) uint64 {
   714  	// Calculate G1 point, scalar value pair length
   715  	k := len(input) / 160
   716  	if k == 0 {
   717  		// Return 0 gas for small input length
   718  		return 0
   719  	}
   720  	// Lookup discount value for G1 point, scalar value pair length
   721  	var discount uint64
   722  	if dLen := len(params.Bls12381MultiExpDiscountTable); k < dLen {
   723  		discount = params.Bls12381MultiExpDiscountTable[k-1]
   724  	} else {
   725  		discount = params.Bls12381MultiExpDiscountTable[dLen-1]
   726  	}
   727  	// Calculate gas and return the result
   728  	return (uint64(k) * params.Bls12381G1MulGas * discount) / 1000
   729  }
   730  
   731  func (c *bls12381G1MultiExp) Run(input []byte) ([]byte, error) {
   732  	// Implements EIP-2537 G1MultiExp precompile.
   733  	// 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).
   734  	// Output is an encoding of multiexponentiation operation result - single G1 point (`128` bytes).
   735  	k := len(input) / 160
   736  	if len(input) == 0 || len(input)%160 != 0 {
   737  		return nil, errBLS12381InvalidInputLength
   738  	}
   739  	var err error
   740  	points := make([]*bls12381.PointG1, k)
   741  	scalars := make([]*big.Int, k)
   742  
   743  	// Initialize G1
   744  	g := bls12381.NewG1()
   745  
   746  	// Decode point scalar pairs
   747  	for i := 0; i < k; i++ {
   748  		off := 160 * i
   749  		t0, t1, t2 := off, off+128, off+160
   750  		// Decode G1 point
   751  		if points[i], err = g.DecodePoint(input[t0:t1]); err != nil {
   752  			return nil, err
   753  		}
   754  		// Decode scalar value
   755  		scalars[i] = new(big.Int).SetBytes(input[t1:t2])
   756  	}
   757  
   758  	// Compute r = e_0 * p_0 + e_1 * p_1 + ... + e_(k-1) * p_(k-1)
   759  	r := g.New()
   760  	g.MultiExp(r, points, scalars)
   761  
   762  	// Encode the G1 point to 128 bytes
   763  	return g.EncodePoint(r), nil
   764  }
   765  
   766  // bls12381G2Add implements EIP-2537 G2Add precompile.
   767  type bls12381G2Add struct{}
   768  
   769  // RequiredGas returns the gas required to execute the pre-compiled contract.
   770  func (c *bls12381G2Add) RequiredGas(input []byte) uint64 {
   771  	return params.Bls12381G2AddGas
   772  }
   773  
   774  func (c *bls12381G2Add) Run(input []byte) ([]byte, error) {
   775  	// Implements EIP-2537 G2Add precompile.
   776  	// > G2 addition call expects `512` bytes as an input that is interpreted as byte concatenation of two G2 points (`256` bytes each).
   777  	// > Output is an encoding of addition operation result - single G2 point (`256` bytes).
   778  	if len(input) != 512 {
   779  		return nil, errBLS12381InvalidInputLength
   780  	}
   781  	var err error
   782  	var p0, p1 *bls12381.PointG2
   783  
   784  	// Initialize G2
   785  	g := bls12381.NewG2()
   786  	r := g.New()
   787  
   788  	// Decode G2 point p_0
   789  	if p0, err = g.DecodePoint(input[:256]); err != nil {
   790  		return nil, err
   791  	}
   792  	// Decode G2 point p_1
   793  	if p1, err = g.DecodePoint(input[256:]); err != nil {
   794  		return nil, err
   795  	}
   796  
   797  	// Compute r = p_0 + p_1
   798  	g.Add(r, p0, p1)
   799  
   800  	// Encode the G2 point into 256 bytes
   801  	return g.EncodePoint(r), nil
   802  }
   803  
   804  // bls12381G2Mul implements EIP-2537 G2Mul precompile.
   805  type bls12381G2Mul struct{}
   806  
   807  // RequiredGas returns the gas required to execute the pre-compiled contract.
   808  func (c *bls12381G2Mul) RequiredGas(input []byte) uint64 {
   809  	return params.Bls12381G2MulGas
   810  }
   811  
   812  func (c *bls12381G2Mul) Run(input []byte) ([]byte, error) {
   813  	// Implements EIP-2537 G2MUL precompile logic.
   814  	// > 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).
   815  	// > Output is an encoding of multiplication operation result - single G2 point (`256` bytes).
   816  	if len(input) != 288 {
   817  		return nil, errBLS12381InvalidInputLength
   818  	}
   819  	var err error
   820  	var p0 *bls12381.PointG2
   821  
   822  	// Initialize G2
   823  	g := bls12381.NewG2()
   824  
   825  	// Decode G2 point
   826  	if p0, err = g.DecodePoint(input[:256]); err != nil {
   827  		return nil, err
   828  	}
   829  	// Decode scalar value
   830  	e := new(big.Int).SetBytes(input[256:])
   831  
   832  	// Compute r = e * p_0
   833  	r := g.New()
   834  	g.MulScalar(r, p0, e)
   835  
   836  	// Encode the G2 point into 256 bytes
   837  	return g.EncodePoint(r), nil
   838  }
   839  
   840  // bls12381G2MultiExp implements EIP-2537 G2MultiExp precompile.
   841  type bls12381G2MultiExp struct{}
   842  
   843  // RequiredGas returns the gas required to execute the pre-compiled contract.
   844  func (c *bls12381G2MultiExp) RequiredGas(input []byte) uint64 {
   845  	// Calculate G2 point, scalar value pair length
   846  	k := len(input) / 288
   847  	if k == 0 {
   848  		// Return 0 gas for small input length
   849  		return 0
   850  	}
   851  	// Lookup discount value for G2 point, scalar value pair length
   852  	var discount uint64
   853  	if dLen := len(params.Bls12381MultiExpDiscountTable); k < dLen {
   854  		discount = params.Bls12381MultiExpDiscountTable[k-1]
   855  	} else {
   856  		discount = params.Bls12381MultiExpDiscountTable[dLen-1]
   857  	}
   858  	// Calculate gas and return the result
   859  	return (uint64(k) * params.Bls12381G2MulGas * discount) / 1000
   860  }
   861  
   862  func (c *bls12381G2MultiExp) Run(input []byte) ([]byte, error) {
   863  	// Implements EIP-2537 G2MultiExp precompile logic
   864  	// > 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).
   865  	// > Output is an encoding of multiexponentiation operation result - single G2 point (`256` bytes).
   866  	k := len(input) / 288
   867  	if len(input) == 0 || len(input)%288 != 0 {
   868  		return nil, errBLS12381InvalidInputLength
   869  	}
   870  	var err error
   871  	points := make([]*bls12381.PointG2, k)
   872  	scalars := make([]*big.Int, k)
   873  
   874  	// Initialize G2
   875  	g := bls12381.NewG2()
   876  
   877  	// Decode point scalar pairs
   878  	for i := 0; i < k; i++ {
   879  		off := 288 * i
   880  		t0, t1, t2 := off, off+256, off+288
   881  		// Decode G1 point
   882  		if points[i], err = g.DecodePoint(input[t0:t1]); err != nil {
   883  			return nil, err
   884  		}
   885  		// Decode scalar value
   886  		scalars[i] = new(big.Int).SetBytes(input[t1:t2])
   887  	}
   888  
   889  	// Compute r = e_0 * p_0 + e_1 * p_1 + ... + e_(k-1) * p_(k-1)
   890  	r := g.New()
   891  	g.MultiExp(r, points, scalars)
   892  
   893  	// Encode the G2 point to 256 bytes.
   894  	return g.EncodePoint(r), nil
   895  }
   896  
   897  // bls12381Pairing implements EIP-2537 Pairing precompile.
   898  type bls12381Pairing struct{}
   899  
   900  // RequiredGas returns the gas required to execute the pre-compiled contract.
   901  func (c *bls12381Pairing) RequiredGas(input []byte) uint64 {
   902  	return params.Bls12381PairingBaseGas + uint64(len(input)/384)*params.Bls12381PairingPerPairGas
   903  }
   904  
   905  func (c *bls12381Pairing) Run(input []byte) ([]byte, error) {
   906  	// Implements EIP-2537 Pairing precompile logic.
   907  	// > Pairing call expects `384*k` bytes as an inputs that is interpreted as byte concatenation of `k` slices. Each slice has the following structure:
   908  	// > - `128` bytes of G1 point encoding
   909  	// > - `256` bytes of G2 point encoding
   910  	// > 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
   911  	// > (which is equivalent of Big Endian encoding of Solidity values `uint256(1)` and `uin256(0)` respectively).
   912  	k := len(input) / 384
   913  	if len(input) == 0 || len(input)%384 != 0 {
   914  		return nil, errBLS12381InvalidInputLength
   915  	}
   916  
   917  	// Initialize BLS12-381 pairing engine
   918  	e := bls12381.NewPairingEngine()
   919  	g1, g2 := e.G1, e.G2
   920  
   921  	// Decode pairs
   922  	for i := 0; i < k; i++ {
   923  		off := 384 * i
   924  		t0, t1, t2 := off, off+128, off+384
   925  
   926  		// Decode G1 point
   927  		p1, err := g1.DecodePoint(input[t0:t1])
   928  		if err != nil {
   929  			return nil, err
   930  		}
   931  		// Decode G2 point
   932  		p2, err := g2.DecodePoint(input[t1:t2])
   933  		if err != nil {
   934  			return nil, err
   935  		}
   936  
   937  		// 'point is on curve' check already done,
   938  		// Here we need to apply subgroup checks.
   939  		if !g1.InCorrectSubgroup(p1) {
   940  			return nil, errBLS12381G1PointSubgroup
   941  		}
   942  		if !g2.InCorrectSubgroup(p2) {
   943  			return nil, errBLS12381G2PointSubgroup
   944  		}
   945  
   946  		// Update pairing engine with G1 and G2 points
   947  		e.AddPair(p1, p2)
   948  	}
   949  	// Prepare 32 byte output
   950  	out := make([]byte, 32)
   951  
   952  	// Compute pairing and set the result
   953  	if e.Check() {
   954  		out[31] = 1
   955  	}
   956  	return out, nil
   957  }
   958  
   959  // decodeBLS12381FieldElement decodes BLS12-381 elliptic curve field element.
   960  // Removes top 16 bytes of 64 byte input.
   961  func decodeBLS12381FieldElement(in []byte) ([]byte, error) {
   962  	if len(in) != 64 {
   963  		return nil, errors.New("invalid field element length")
   964  	}
   965  	// check top bytes
   966  	for i := 0; i < 16; i++ {
   967  		if in[i] != byte(0x00) {
   968  			return nil, errBLS12381InvalidFieldElementTopBytes
   969  		}
   970  	}
   971  	out := make([]byte, 48)
   972  	copy(out[:], in[16:])
   973  	return out, nil
   974  }
   975  
   976  // bls12381MapG1 implements EIP-2537 MapG1 precompile.
   977  type bls12381MapG1 struct{}
   978  
   979  // RequiredGas returns the gas required to execute the pre-compiled contract.
   980  func (c *bls12381MapG1) RequiredGas(input []byte) uint64 {
   981  	return params.Bls12381MapG1Gas
   982  }
   983  
   984  func (c *bls12381MapG1) Run(input []byte) ([]byte, error) {
   985  	// Implements EIP-2537 Map_To_G1 precompile.
   986  	// > Field-to-curve call expects `64` bytes an an input that is interpreted as a an element of the base field.
   987  	// > Output of this call is `128` bytes and is G1 point following respective encoding rules.
   988  	if len(input) != 64 {
   989  		return nil, errBLS12381InvalidInputLength
   990  	}
   991  
   992  	// Decode input field element
   993  	fe, err := decodeBLS12381FieldElement(input)
   994  	if err != nil {
   995  		return nil, err
   996  	}
   997  
   998  	// Initialize G1
   999  	g := bls12381.NewG1()
  1000  
  1001  	// Compute mapping
  1002  	r, err := g.MapToCurve(fe)
  1003  	if err != nil {
  1004  		return nil, err
  1005  	}
  1006  
  1007  	// Encode the G1 point to 128 bytes
  1008  	return g.EncodePoint(r), nil
  1009  }
  1010  
  1011  // bls12381MapG2 implements EIP-2537 MapG2 precompile.
  1012  type bls12381MapG2 struct{}
  1013  
  1014  // RequiredGas returns the gas required to execute the pre-compiled contract.
  1015  func (c *bls12381MapG2) RequiredGas(input []byte) uint64 {
  1016  	return params.Bls12381MapG2Gas
  1017  }
  1018  
  1019  func (c *bls12381MapG2) Run(input []byte) ([]byte, error) {
  1020  	// Implements EIP-2537 Map_FP2_TO_G2 precompile logic.
  1021  	// > Field-to-curve call expects `128` bytes an an input that is interpreted as a an element of the quadratic extension field.
  1022  	// > Output of this call is `256` bytes and is G2 point following respective encoding rules.
  1023  	if len(input) != 128 {
  1024  		return nil, errBLS12381InvalidInputLength
  1025  	}
  1026  
  1027  	// Decode input field element
  1028  	fe := make([]byte, 96)
  1029  	c0, err := decodeBLS12381FieldElement(input[:64])
  1030  	if err != nil {
  1031  		return nil, err
  1032  	}
  1033  	copy(fe[48:], c0)
  1034  	c1, err := decodeBLS12381FieldElement(input[64:])
  1035  	if err != nil {
  1036  		return nil, err
  1037  	}
  1038  	copy(fe[:48], c1)
  1039  
  1040  	// Initialize G2
  1041  	g := bls12381.NewG2()
  1042  
  1043  	// Compute mapping
  1044  	r, err := g.MapToCurve(fe)
  1045  	if err != nil {
  1046  		return nil, err
  1047  	}
  1048  
  1049  	// Encode the G2 point to 256 bytes
  1050  	return g.EncodePoint(r), nil
  1051  }