78 lines
1.8 KiB
Go
78 lines
1.8 KiB
Go
package vm
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import (
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"math/big"
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"github.com/ethereum/go-ethereum/crypto"
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"github.com/ethereum/go-ethereum/ethutil"
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)
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type Address interface {
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Call(in []byte) []byte
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}
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type PrecompiledAccount struct {
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Gas func(l int) *big.Int
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fn func(in []byte) []byte
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}
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func (self PrecompiledAccount) Call(in []byte) []byte {
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return self.fn(in)
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}
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var Precompiled = PrecompiledContracts()
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// XXX Could set directly. Testing requires resetting and setting of pre compiled contracts.
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func PrecompiledContracts() map[string]*PrecompiledAccount {
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return map[string]*PrecompiledAccount{
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// ECRECOVER
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string(ethutil.LeftPadBytes([]byte{1}, 20)): &PrecompiledAccount{func(l int) *big.Int {
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return GasEcrecover
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}, ecrecoverFunc},
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// SHA256
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string(ethutil.LeftPadBytes([]byte{2}, 20)): &PrecompiledAccount{func(l int) *big.Int {
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n := big.NewInt(int64(l+31)/32 + 1)
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n.Mul(n, GasSha256)
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return n
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}, sha256Func},
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// RIPEMD160
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string(ethutil.LeftPadBytes([]byte{3}, 20)): &PrecompiledAccount{func(l int) *big.Int {
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n := big.NewInt(int64(l+31)/32 + 1)
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n.Mul(n, GasRipemd)
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return n
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}, ripemd160Func},
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string(ethutil.LeftPadBytes([]byte{4}, 20)): &PrecompiledAccount{func(l int) *big.Int {
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n := big.NewInt(int64(l+31)/32 + 1)
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n.Mul(n, GasMemCpy)
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return n
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}, memCpy},
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}
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}
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func sha256Func(in []byte) []byte {
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return crypto.Sha256(in)
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}
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func ripemd160Func(in []byte) []byte {
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return ethutil.LeftPadBytes(crypto.Ripemd160(in), 32)
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}
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func ecrecoverFunc(in []byte) []byte {
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// In case of an invalid sig. Defaults to return nil
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defer func() { recover() }()
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hash := in[:32]
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v := ethutil.BigD(in[32:64]).Bytes()[0] - 27
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sig := append(in[64:], v)
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return ethutil.LeftPadBytes(crypto.Sha3(crypto.Ecrecover(append(hash, sig...))[1:])[12:], 32)
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}
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func memCpy(in []byte) []byte {
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return in
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}
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