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-rw-r--r--core/vm/contracts.go349
1 files changed, 192 insertions, 157 deletions
diff --git a/core/vm/contracts.go b/core/vm/contracts.go
index 407f198f0..c59779dac 100644
--- a/core/vm/contracts.go
+++ b/core/vm/contracts.go
@@ -29,9 +29,7 @@ import (
"golang.org/x/crypto/ripemd160"
)
-var errBadPrecompileInput = errors.New("bad pre compile input")
-
-// Precompiled contract is the basic interface for native Go contracts. The implementation
+// PrecompiledContract is the basic interface for native Go contracts. The implementation
// requires a deterministic gas count based on the input size of the Run method of the
// contract.
type PrecompiledContract interface {
@@ -39,61 +37,61 @@ type PrecompiledContract interface {
Run(input []byte) ([]byte, error) // Run runs the precompiled contract
}
-// PrecompiledContracts contains the default set of ethereum contracts
-var PrecompiledContracts = map[common.Address]PrecompiledContract{
+// PrecompiledContractsHomestead contains the default set of pre-compiled Ethereum
+// contracts used in the Frontier and Homestead releases.
+var PrecompiledContractsHomestead = map[common.Address]PrecompiledContract{
common.BytesToAddress([]byte{1}): &ecrecover{},
common.BytesToAddress([]byte{2}): &sha256hash{},
common.BytesToAddress([]byte{3}): &ripemd160hash{},
common.BytesToAddress([]byte{4}): &dataCopy{},
}
-// PrecompiledContractsMetropolis contains the default set of ethereum contracts
-// for metropolis hardfork
+// PrecompiledContractsMetropolis contains the default set of pre-compiled Ethereum
+// contracts used in the Metropolis release.
var PrecompiledContractsMetropolis = map[common.Address]PrecompiledContract{
common.BytesToAddress([]byte{1}): &ecrecover{},
common.BytesToAddress([]byte{2}): &sha256hash{},
common.BytesToAddress([]byte{3}): &ripemd160hash{},
common.BytesToAddress([]byte{4}): &dataCopy{},
- common.BytesToAddress([]byte{5}): &bigModexp{},
+ common.BytesToAddress([]byte{5}): &bigModExp{},
common.BytesToAddress([]byte{6}): &bn256Add{},
common.BytesToAddress([]byte{7}): &bn256ScalarMul{},
- common.BytesToAddress([]byte{8}): &pairing{},
+ common.BytesToAddress([]byte{8}): &bn256Pairing{},
}
-// RunPrecompile runs and evaluate the output of a precompiled contract defined in contracts.go
+// RunPrecompiledContract runs and evaluates the output of a precompiled contract.
func RunPrecompiledContract(p PrecompiledContract, input []byte, contract *Contract) (ret []byte, err error) {
gas := p.RequiredGas(input)
if contract.UseGas(gas) {
return p.Run(input)
- } else {
- return nil, ErrOutOfGas
}
+ return nil, ErrOutOfGas
}
-// ECRECOVER implemented as a native contract
+// ECRECOVER implemented as a native contract.
type ecrecover struct{}
func (c *ecrecover) RequiredGas(input []byte) uint64 {
return params.EcrecoverGas
}
-func (c *ecrecover) Run(in []byte) ([]byte, error) {
+func (c *ecrecover) Run(input []byte) ([]byte, error) {
const ecRecoverInputLength = 128
- in = common.RightPadBytes(in, ecRecoverInputLength)
- // "in" is (hash, v, r, s), each 32 bytes
+ input = common.RightPadBytes(input, ecRecoverInputLength)
+ // "input" is (hash, v, r, s), each 32 bytes
// but for ecrecover we want (r, s, v)
- r := new(big.Int).SetBytes(in[64:96])
- s := new(big.Int).SetBytes(in[96:128])
- v := in[63] - 27
+ r := new(big.Int).SetBytes(input[64:96])
+ s := new(big.Int).SetBytes(input[96:128])
+ v := input[63] - 27
- // tighter sig s values in homestead only apply to tx sigs
- if !allZero(in[32:63]) || !crypto.ValidateSignatureValues(v, r, s, false) {
+ // tighter sig s values input homestead only apply to tx sigs
+ if !allZero(input[32:63]) || !crypto.ValidateSignatureValues(v, r, s, false) {
return nil, nil
}
// v needs to be at the end for libsecp256k1
- pubKey, err := crypto.Ecrecover(in[:32], append(in[64:128], v))
+ pubKey, err := crypto.Ecrecover(input[:32], append(input[64:128], v))
// make sure the public key is a valid one
if err != nil {
return nil, nil
@@ -103,7 +101,7 @@ func (c *ecrecover) Run(in []byte) ([]byte, error) {
return common.LeftPadBytes(crypto.Keccak256(pubKey[1:])[12:], 32), nil
}
-// SHA256 implemented as a native contract
+// SHA256 implemented as a native contract.
type sha256hash struct{}
// RequiredGas returns the gas required to execute the pre-compiled contract.
@@ -111,14 +109,14 @@ type sha256hash struct{}
// This method does not require any overflow checking as the input size gas costs
// required for anything significant is so high it's impossible to pay for.
func (c *sha256hash) RequiredGas(input []byte) uint64 {
- return uint64(len(input)+31)/32*params.Sha256WordGas + params.Sha256Gas
+ return uint64(len(input)+31)/32*params.Sha256PerWordGas + params.Sha256BaseGas
}
-func (c *sha256hash) Run(in []byte) ([]byte, error) {
- h := sha256.Sum256(in)
+func (c *sha256hash) Run(input []byte) ([]byte, error) {
+ h := sha256.Sum256(input)
return h[:], nil
}
-// RIPMED160 implemented as a native contract
+// RIPMED160 implemented as a native contract.
type ripemd160hash struct{}
// RequiredGas returns the gas required to execute the pre-compiled contract.
@@ -126,15 +124,15 @@ type ripemd160hash struct{}
// This method does not require any overflow checking as the input size gas costs
// required for anything significant is so high it's impossible to pay for.
func (c *ripemd160hash) RequiredGas(input []byte) uint64 {
- return uint64(len(input)+31)/32*params.Ripemd160WordGas + params.Ripemd160Gas
+ return uint64(len(input)+31)/32*params.Ripemd160PerWordGas + params.Ripemd160BaseGas
}
-func (c *ripemd160hash) Run(in []byte) ([]byte, error) {
+func (c *ripemd160hash) Run(input []byte) ([]byte, error) {
ripemd := ripemd160.New()
- ripemd.Write(in)
+ ripemd.Write(input)
return common.LeftPadBytes(ripemd.Sum(nil), 32), nil
}
-// data copy implemented as a native contract
+// data copy implemented as a native contract.
type dataCopy struct{}
// RequiredGas returns the gas required to execute the pre-compiled contract.
@@ -142,195 +140,232 @@ type dataCopy struct{}
// This method does not require any overflow checking as the input size gas costs
// required for anything significant is so high it's impossible to pay for.
func (c *dataCopy) RequiredGas(input []byte) uint64 {
- return uint64(len(input)+31)/32*params.IdentityWordGas + params.IdentityGas
+ return uint64(len(input)+31)/32*params.IdentityPerWordGas + params.IdentityBaseGas
}
func (c *dataCopy) Run(in []byte) ([]byte, error) {
return in, nil
}
-// bigModexp implements a native big integer exponential modular operation.
-type bigModexp struct{}
+// bigModExp implements a native big integer exponential modular operation.
+type bigModExp struct{}
// RequiredGas returns the gas required to execute the pre-compiled contract.
-//
-// This method does not require any overflow checking as the input size gas costs
-// required for anything significant is so high it's impossible to pay for.
-func (c *bigModexp) RequiredGas(input []byte) uint64 {
- // TODO reword required gas to have error reporting and convert arithmetic
- // to uint64.
- if len(input) < 3*32 {
- input = append(input, make([]byte, 3*32-len(input))...)
- }
+func (c *bigModExp) RequiredGas(input []byte) uint64 {
+ // Pad the input with zeroes to the minimum size to read the field lengths
+ input = common.RightPadBytes(input, 96)
+
var (
- baseLen = new(big.Int).SetBytes(input[:31])
- expLen = math.BigMax(new(big.Int).SetBytes(input[32:64]), big.NewInt(1))
- modLen = new(big.Int).SetBytes(input[65:97])
+ baseLen = new(big.Int).SetBytes(input[:32])
+ expLen = new(big.Int).SetBytes(input[32:64])
+ modLen = new(big.Int).SetBytes(input[64:96])
)
- x := new(big.Int).Set(math.BigMax(baseLen, modLen))
- x.Mul(x, x)
- x.Mul(x, expLen)
- x.Div(x, new(big.Int).SetUint64(params.QuadCoeffDiv))
+ input = input[96:]
- return x.Uint64()
-}
+ // Retrieve the head 32 bytes of exp for the adjusted exponent length
+ var expHead *big.Int
+ if big.NewInt(int64(len(input))).Cmp(baseLen) <= 0 {
+ expHead = new(big.Int)
+ } else {
+ offset := int(baseLen.Uint64())
-func (c *bigModexp) Run(input []byte) ([]byte, error) {
- if len(input) < 3*32 {
- input = append(input, make([]byte, 3*32-len(input))...)
+ input = common.RightPadBytes(input, offset+32)
+ if expLen.Cmp(big.NewInt(32)) > 0 {
+ expHead = new(big.Int).SetBytes(input[offset : offset+32])
+ } else {
+ expHead = new(big.Int).SetBytes(input[offset : offset+int(expLen.Uint64())])
+ }
}
- // why 32-byte? These values won't fit anyway
+ // Calculate the adjusted exponent length
+ var msb int
+ if bitlen := expHead.BitLen(); bitlen > 0 {
+ msb = bitlen - 1
+ }
+ adjExpLen := new(big.Int)
+ if expLen.Cmp(big.NewInt(32)) > 0 {
+ adjExpLen.Sub(expLen, big.NewInt(32))
+ adjExpLen.Mul(big.NewInt(8), adjExpLen)
+ }
+ adjExpLen.Add(adjExpLen, big.NewInt(int64(msb)))
+
+ // Calculate the gas cost of the operation
+ gas := new(big.Int).Set(math.BigMax(modLen, baseLen))
+ switch {
+ case gas.Cmp(big.NewInt(64)) <= 0:
+ gas.Mul(gas, gas)
+ case gas.Cmp(big.NewInt(1024)) <= 0:
+ gas = new(big.Int).Add(
+ new(big.Int).Div(new(big.Int).Mul(gas, gas), big.NewInt(4)),
+ new(big.Int).Sub(new(big.Int).Mul(big.NewInt(96), gas), big.NewInt(3072)),
+ )
+ default:
+ gas = new(big.Int).Add(
+ new(big.Int).Div(new(big.Int).Mul(gas, gas), big.NewInt(16)),
+ new(big.Int).Sub(new(big.Int).Mul(big.NewInt(480), gas), big.NewInt(199680)),
+ )
+ }
+ gas.Mul(gas, math.BigMax(adjExpLen, big.NewInt(1)))
+ gas.Div(gas, new(big.Int).SetUint64(params.ModExpQuadCoeffDiv))
+
+ if gas.BitLen() > 64 {
+ return math.MaxUint64
+ }
+ return gas.Uint64()
+}
+
+func (c *bigModExp) Run(input []byte) ([]byte, error) {
+ // Pad the input with zeroes to the minimum size to read the field lengths
+ input = common.RightPadBytes(input, 96)
+
var (
baseLen = new(big.Int).SetBytes(input[:32]).Uint64()
expLen = new(big.Int).SetBytes(input[32:64]).Uint64()
modLen = new(big.Int).SetBytes(input[64:96]).Uint64()
)
-
input = input[96:]
- if uint64(len(input)) < baseLen {
- input = append(input, make([]byte, baseLen-uint64(len(input)))...)
- }
- base := new(big.Int).SetBytes(input[:baseLen])
- input = input[baseLen:]
- if uint64(len(input)) < expLen {
- input = append(input, make([]byte, expLen-uint64(len(input)))...)
- }
- exp := new(big.Int).SetBytes(input[:expLen])
+ // Pad the input with zeroes to the minimum size to read the field contents
+ input = common.RightPadBytes(input, int(baseLen+expLen+modLen))
- input = input[expLen:]
- if uint64(len(input)) < modLen {
- input = append(input, make([]byte, modLen-uint64(len(input)))...)
+ var (
+ base = new(big.Int).SetBytes(input[:baseLen])
+ exp = new(big.Int).SetBytes(input[baseLen : baseLen+expLen])
+ mod = new(big.Int).SetBytes(input[baseLen+expLen : baseLen+expLen+modLen])
+ )
+ if mod.BitLen() == 0 {
+ // Modulo 0 is undefined, return zero
+ return common.LeftPadBytes([]byte{}, int(modLen)), nil
}
- mod := new(big.Int).SetBytes(input[:modLen])
-
- return common.LeftPadBytes(base.Exp(base, exp, mod).Bytes(), len(input[:modLen])), nil
+ return common.LeftPadBytes(base.Exp(base, exp, mod).Bytes(), int(modLen)), nil
}
-type bn256Add struct{}
-
-// RequiredGas returns the gas required to execute the pre-compiled contract.
-//
-// This method does not require any overflow checking as the input size gas costs
-// required for anything significant is so high it's impossible to pay for.
-func (c *bn256Add) RequiredGas(input []byte) uint64 {
- return 0 // TODO
-}
+var (
+ // errNotOnCurve is returned if a point being unmarshalled as a bn256 elliptic
+ // curve point is not on the curve.
+ errNotOnCurve = errors.New("point not on elliptic curve")
-func (c *bn256Add) Run(in []byte) ([]byte, error) {
- in = common.RightPadBytes(in, 128)
+ // errInvalidCurvePoint is returned if a point being unmarshalled as a bn256
+ // elliptic curve point is invalid.
+ errInvalidCurvePoint = errors.New("invalid elliptic curve point")
+)
- x, onCurve := new(bn256.G1).Unmarshal(in[:64])
+// newCurvePoint unmarshals a binary blob into a bn256 elliptic curve point,
+// returning it, or an error if the point is invalid.
+func newCurvePoint(blob []byte) (*bn256.G1, error) {
+ p, onCurve := new(bn256.G1).Unmarshal(blob)
if !onCurve {
return nil, errNotOnCurve
}
- gx, gy, _, _ := x.CurvePoints()
+ gx, gy, _, _ := p.CurvePoints()
if gx.Cmp(bn256.P) >= 0 || gy.Cmp(bn256.P) >= 0 {
return nil, errInvalidCurvePoint
}
+ return p, nil
+}
- y, onCurve := new(bn256.G1).Unmarshal(in[64:128])
+// newTwistPoint unmarshals a binary blob into a bn256 elliptic curve point,
+// returning it, or an error if the point is invalid.
+func newTwistPoint(blob []byte) (*bn256.G2, error) {
+ p, onCurve := new(bn256.G2).Unmarshal(blob)
if !onCurve {
return nil, errNotOnCurve
}
- gx, gy, _, _ = y.CurvePoints()
- if gx.Cmp(bn256.P) >= 0 || gy.Cmp(bn256.P) >= 0 {
+ x2, y2, _, _ := p.CurvePoints()
+ if x2.Real().Cmp(bn256.P) >= 0 || x2.Imag().Cmp(bn256.P) >= 0 ||
+ y2.Real().Cmp(bn256.P) >= 0 || y2.Imag().Cmp(bn256.P) >= 0 {
return nil, errInvalidCurvePoint
}
- x.Add(x, y)
-
- return x.Marshal(), nil
+ return p, nil
}
-type bn256ScalarMul struct{}
+// bn256Add implements a native elliptic curve point addition.
+type bn256Add struct{}
// RequiredGas returns the gas required to execute the pre-compiled contract.
-//
-// This method does not require any overflow checking as the input size gas costs
-// required for anything significant is so high it's impossible to pay for.
-func (c *bn256ScalarMul) RequiredGas(input []byte) uint64 {
- return 0 // TODO
+func (c *bn256Add) RequiredGas(input []byte) uint64 {
+ return params.Bn256AddGas
}
-func (c *bn256ScalarMul) Run(in []byte) ([]byte, error) {
- in = common.RightPadBytes(in, 96)
+func (c *bn256Add) Run(input []byte) ([]byte, error) {
+ // Ensure we have enough data to operate on
+ input = common.RightPadBytes(input, 128)
- g1, onCurve := new(bn256.G1).Unmarshal(in[:64])
- if !onCurve {
- return nil, errNotOnCurve
+ x, err := newCurvePoint(input[:64])
+ if err != nil {
+ return nil, err
}
- x, y, _, _ := g1.CurvePoints()
- if x.Cmp(bn256.P) >= 0 || y.Cmp(bn256.P) >= 0 {
- return nil, errInvalidCurvePoint
+ y, err := newCurvePoint(input[64:128])
+ if err != nil {
+ return nil, err
}
- g1.ScalarMult(g1, new(big.Int).SetBytes(in[64:96]))
-
- return g1.Marshal(), nil
+ x.Add(x, y)
+ return x.Marshal(), nil
}
-// pairing implements a pairing pre-compile for the bn256 curve
-type pairing struct{}
+// bn256ScalarMul implements a native elliptic curve scalar multiplication.
+type bn256ScalarMul struct{}
// RequiredGas returns the gas required to execute the pre-compiled contract.
-//
-// This method does not require any overflow checking as the input size gas costs
-// required for anything significant is so high it's impossible to pay for.
-func (c *pairing) RequiredGas(input []byte) uint64 {
- //return 0 // TODO
- k := (len(input) + 191) / pairSize
- return uint64(60000*k + 40000)
+func (c *bn256ScalarMul) RequiredGas(input []byte) uint64 {
+ return params.Bn256ScalarMulGas
}
-const pairSize = 192
+func (c *bn256ScalarMul) Run(input []byte) ([]byte, error) {
+ // Ensure we have enough data to operate on
+ input = common.RightPadBytes(input, 96)
+
+ p, err := newCurvePoint(input[:64])
+ if err != nil {
+ return nil, err
+ }
+ p.ScalarMult(p, new(big.Int).SetBytes(input[64:96]))
+ return p.Marshal(), nil
+}
var (
- 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}
- fals32Byte = make([]byte, 32)
- errNotOnCurve = errors.New("point not on elliptic curve")
- errInvalidCurvePoint = errors.New("invalid elliptic curve point")
+ // true32Byte is returned if the bn256 pairing check succeeds.
+ 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}
+
+ // false32Byte is returned if the bn256 pairing check fails.
+ false32Byte = make([]byte, 32)
+
+ // errBadPairingInput is returned if the bn256 pairing input is invalid.
+ errBadPairingInput = errors.New("bad elliptic curve pairing size")
)
-func (c *pairing) Run(in []byte) ([]byte, error) {
- if len(in) == 0 {
- return true32Byte, nil
- }
+// bn256Pairing implements a pairing pre-compile for the bn256 curve
+type bn256Pairing struct{}
- if len(in)%pairSize > 0 {
- return nil, errBadPrecompileInput
- }
+// RequiredGas returns the gas required to execute the pre-compiled contract.
+func (c *bn256Pairing) RequiredGas(input []byte) uint64 {
+ return params.Bn256PairingBaseGas + uint64(len(input)/192)*params.Bn256PairingPerPointGas
+}
+func (c *bn256Pairing) Run(input []byte) ([]byte, error) {
+ // Handle some corner cases cheaply
+ if len(input)%192 > 0 {
+ return nil, errBadPairingInput
+ }
+ // Convert the input into a set of coordinates
var (
- g1s []*bn256.G1
- g2s []*bn256.G2
+ cs []*bn256.G1
+ ts []*bn256.G2
)
- for i := 0; i < len(in); i += pairSize {
- g1, onCurve := new(bn256.G1).Unmarshal(in[i : i+64])
- if !onCurve {
- return nil, errNotOnCurve
- }
-
- x, y, _, _ := g1.CurvePoints()
- if x.Cmp(bn256.P) >= 0 || y.Cmp(bn256.P) >= 0 {
- return nil, errInvalidCurvePoint
+ for i := 0; i < len(input); i += 192 {
+ c, err := newCurvePoint(input[i : i+64])
+ if err != nil {
+ return nil, err
}
-
- g2, onCurve := new(bn256.G2).Unmarshal(in[i+64 : i+192])
- if !onCurve {
- return nil, errNotOnCurve
- }
- x2, y2, _, _ := g2.CurvePoints()
- if x2.Real().Cmp(bn256.P) >= 0 || x2.Imag().Cmp(bn256.P) >= 0 ||
- y2.Real().Cmp(bn256.P) >= 0 || y2.Imag().Cmp(bn256.P) >= 0 {
- return nil, errInvalidCurvePoint
+ t, err := newTwistPoint(input[i+64 : i+192])
+ if err != nil {
+ return nil, err
}
-
- g1s = append(g1s, g1)
- g2s = append(g2s, g2)
+ cs = append(cs, c)
+ ts = append(ts, t)
}
-
- isOne := bn256.PairingCheck(g1s, g2s)
- if isOne {
+ // Execute the pairing checks and return the results
+ ok := bn256.PairingCheck(cs, ts)
+ if ok {
return true32Byte, nil
}
-
- return fals32Byte, nil
+ return false32Byte, nil
}
generated by cgit (git 2.34.1) at 2024-11-14 04:05:06 +0800