505 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			505 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright 2014 The go-ethereum Authors
 | |
| // This file is part of the go-ethereum library.
 | |
| //
 | |
| // The go-ethereum library is free software: you can redistribute it and/or modify
 | |
| // it under the terms of the GNU Lesser General Public License as published by
 | |
| // the Free Software Foundation, either version 3 of the License, or
 | |
| // (at your option) any later version.
 | |
| //
 | |
| // The go-ethereum library is distributed in the hope that it will be useful,
 | |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of
 | |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 | |
| // GNU Lesser General Public License for more details.
 | |
| //
 | |
| // You should have received a copy of the GNU Lesser General Public License
 | |
| // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 | |
| 
 | |
| package vm
 | |
| 
 | |
| import (
 | |
| 	"crypto/sha256"
 | |
| 	"encoding/binary"
 | |
| 	"errors"
 | |
| 	"math/big"
 | |
| 
 | |
| 	"github.com/ethereum/go-ethereum/common"
 | |
| 	"github.com/ethereum/go-ethereum/common/math"
 | |
| 	"github.com/ethereum/go-ethereum/crypto"
 | |
| 	"github.com/ethereum/go-ethereum/crypto/blake2b"
 | |
| 	"github.com/ethereum/go-ethereum/crypto/bn256"
 | |
| 	"github.com/ethereum/go-ethereum/params"
 | |
| 
 | |
| 	//lint:ignore SA1019 Needed for precompile
 | |
| 	"golang.org/x/crypto/ripemd160"
 | |
| )
 | |
| 
 | |
| // 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 {
 | |
| 	RequiredGas(input []byte) uint64  // RequiredPrice calculates the contract gas use
 | |
| 	Run(input []byte) ([]byte, error) // Run runs the precompiled contract
 | |
| }
 | |
| 
 | |
| // 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{},
 | |
| }
 | |
| 
 | |
| // PrecompiledContractsByzantium contains the default set of pre-compiled Ethereum
 | |
| // contracts used in the Byzantium release.
 | |
| var PrecompiledContractsByzantium = 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{6}): &bn256AddByzantium{},
 | |
| 	common.BytesToAddress([]byte{7}): &bn256ScalarMulByzantium{},
 | |
| 	common.BytesToAddress([]byte{8}): &bn256PairingByzantium{},
 | |
| }
 | |
| 
 | |
| // PrecompiledContractsIstanbul contains the default set of pre-compiled Ethereum
 | |
| // contracts used in the Istanbul release.
 | |
| var PrecompiledContractsIstanbul = 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{6}): &bn256AddIstanbul{},
 | |
| 	common.BytesToAddress([]byte{7}): &bn256ScalarMulIstanbul{},
 | |
| 	common.BytesToAddress([]byte{8}): &bn256PairingIstanbul{},
 | |
| 	common.BytesToAddress([]byte{9}): &blake2F{},
 | |
| }
 | |
| 
 | |
| // 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)
 | |
| 	}
 | |
| 	return nil, ErrOutOfGas
 | |
| }
 | |
| 
 | |
| // ECRECOVER implemented as a native contract.
 | |
| type ecrecover struct{}
 | |
| 
 | |
| func (c *ecrecover) RequiredGas(input []byte) uint64 {
 | |
| 	return params.EcrecoverGas
 | |
| }
 | |
| 
 | |
| func (c *ecrecover) Run(input []byte) ([]byte, error) {
 | |
| 	const ecRecoverInputLength = 128
 | |
| 
 | |
| 	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(input[64:96])
 | |
| 	s := new(big.Int).SetBytes(input[96:128])
 | |
| 	v := input[63] - 27
 | |
| 
 | |
| 	// 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
 | |
| 	}
 | |
| 	// We must make sure not to modify the 'input', so placing the 'v' along with
 | |
| 	// the signature needs to be done on a new allocation
 | |
| 	sig := make([]byte, 65)
 | |
| 	copy(sig, input[64:128])
 | |
| 	sig[64] = v
 | |
| 	// v needs to be at the end for libsecp256k1
 | |
| 	pubKey, err := crypto.Ecrecover(input[:32], sig)
 | |
| 	// make sure the public key is a valid one
 | |
| 	if err != nil {
 | |
| 		return nil, nil
 | |
| 	}
 | |
| 
 | |
| 	// the first byte of pubkey is bitcoin heritage
 | |
| 	return common.LeftPadBytes(crypto.Keccak256(pubKey[1:])[12:], 32), nil
 | |
| }
 | |
| 
 | |
| // SHA256 implemented as a native contract.
 | |
| type sha256hash 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 *sha256hash) RequiredGas(input []byte) uint64 {
 | |
| 	return uint64(len(input)+31)/32*params.Sha256PerWordGas + params.Sha256BaseGas
 | |
| }
 | |
| func (c *sha256hash) Run(input []byte) ([]byte, error) {
 | |
| 	h := sha256.Sum256(input)
 | |
| 	return h[:], nil
 | |
| }
 | |
| 
 | |
| // RIPEMD160 implemented as a native contract.
 | |
| type ripemd160hash 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 *ripemd160hash) RequiredGas(input []byte) uint64 {
 | |
| 	return uint64(len(input)+31)/32*params.Ripemd160PerWordGas + params.Ripemd160BaseGas
 | |
| }
 | |
| func (c *ripemd160hash) Run(input []byte) ([]byte, error) {
 | |
| 	ripemd := ripemd160.New()
 | |
| 	ripemd.Write(input)
 | |
| 	return common.LeftPadBytes(ripemd.Sum(nil), 32), nil
 | |
| }
 | |
| 
 | |
| // data copy implemented as a native contract.
 | |
| type dataCopy 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 *dataCopy) RequiredGas(input []byte) uint64 {
 | |
| 	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{}
 | |
| 
 | |
| var (
 | |
| 	big1      = big.NewInt(1)
 | |
| 	big4      = big.NewInt(4)
 | |
| 	big8      = big.NewInt(8)
 | |
| 	big16     = big.NewInt(16)
 | |
| 	big32     = big.NewInt(32)
 | |
| 	big64     = big.NewInt(64)
 | |
| 	big96     = big.NewInt(96)
 | |
| 	big480    = big.NewInt(480)
 | |
| 	big1024   = big.NewInt(1024)
 | |
| 	big3072   = big.NewInt(3072)
 | |
| 	big199680 = big.NewInt(199680)
 | |
| )
 | |
| 
 | |
| // RequiredGas returns the gas required to execute the pre-compiled contract.
 | |
| func (c *bigModExp) RequiredGas(input []byte) uint64 {
 | |
| 	var (
 | |
| 		baseLen = new(big.Int).SetBytes(getData(input, 0, 32))
 | |
| 		expLen  = new(big.Int).SetBytes(getData(input, 32, 32))
 | |
| 		modLen  = new(big.Int).SetBytes(getData(input, 64, 32))
 | |
| 	)
 | |
| 	if len(input) > 96 {
 | |
| 		input = input[96:]
 | |
| 	} else {
 | |
| 		input = input[:0]
 | |
| 	}
 | |
| 	// 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 {
 | |
| 		if expLen.Cmp(big32) > 0 {
 | |
| 			expHead = new(big.Int).SetBytes(getData(input, baseLen.Uint64(), 32))
 | |
| 		} else {
 | |
| 			expHead = new(big.Int).SetBytes(getData(input, baseLen.Uint64(), expLen.Uint64()))
 | |
| 		}
 | |
| 	}
 | |
| 	// Calculate the adjusted exponent length
 | |
| 	var msb int
 | |
| 	if bitlen := expHead.BitLen(); bitlen > 0 {
 | |
| 		msb = bitlen - 1
 | |
| 	}
 | |
| 	adjExpLen := new(big.Int)
 | |
| 	if expLen.Cmp(big32) > 0 {
 | |
| 		adjExpLen.Sub(expLen, big32)
 | |
| 		adjExpLen.Mul(big8, 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(big64) <= 0:
 | |
| 		gas.Mul(gas, gas)
 | |
| 	case gas.Cmp(big1024) <= 0:
 | |
| 		gas = new(big.Int).Add(
 | |
| 			new(big.Int).Div(new(big.Int).Mul(gas, gas), big4),
 | |
| 			new(big.Int).Sub(new(big.Int).Mul(big96, gas), big3072),
 | |
| 		)
 | |
| 	default:
 | |
| 		gas = new(big.Int).Add(
 | |
| 			new(big.Int).Div(new(big.Int).Mul(gas, gas), big16),
 | |
| 			new(big.Int).Sub(new(big.Int).Mul(big480, gas), big199680),
 | |
| 		)
 | |
| 	}
 | |
| 	gas.Mul(gas, math.BigMax(adjExpLen, big1))
 | |
| 	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) {
 | |
| 	var (
 | |
| 		baseLen = new(big.Int).SetBytes(getData(input, 0, 32)).Uint64()
 | |
| 		expLen  = new(big.Int).SetBytes(getData(input, 32, 32)).Uint64()
 | |
| 		modLen  = new(big.Int).SetBytes(getData(input, 64, 32)).Uint64()
 | |
| 	)
 | |
| 	if len(input) > 96 {
 | |
| 		input = input[96:]
 | |
| 	} else {
 | |
| 		input = input[:0]
 | |
| 	}
 | |
| 	// Handle a special case when both the base and mod length is zero
 | |
| 	if baseLen == 0 && modLen == 0 {
 | |
| 		return []byte{}, nil
 | |
| 	}
 | |
| 	// Retrieve the operands and execute the exponentiation
 | |
| 	var (
 | |
| 		base = new(big.Int).SetBytes(getData(input, 0, baseLen))
 | |
| 		exp  = new(big.Int).SetBytes(getData(input, baseLen, expLen))
 | |
| 		mod  = new(big.Int).SetBytes(getData(input, baseLen+expLen, modLen))
 | |
| 	)
 | |
| 	if mod.BitLen() == 0 {
 | |
| 		// Modulo 0 is undefined, return zero
 | |
| 		return common.LeftPadBytes([]byte{}, int(modLen)), nil
 | |
| 	}
 | |
| 	return common.LeftPadBytes(base.Exp(base, exp, mod).Bytes(), int(modLen)), nil
 | |
| }
 | |
| 
 | |
| // 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 := new(bn256.G1)
 | |
| 	if _, err := p.Unmarshal(blob); err != nil {
 | |
| 		return nil, err
 | |
| 	}
 | |
| 	return p, nil
 | |
| }
 | |
| 
 | |
| // 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 := new(bn256.G2)
 | |
| 	if _, err := p.Unmarshal(blob); err != nil {
 | |
| 		return nil, err
 | |
| 	}
 | |
| 	return p, nil
 | |
| }
 | |
| 
 | |
| // runBn256Add implements the Bn256Add precompile, referenced by both
 | |
| // Byzantium and Istanbul operations.
 | |
| func runBn256Add(input []byte) ([]byte, error) {
 | |
| 	x, err := newCurvePoint(getData(input, 0, 64))
 | |
| 	if err != nil {
 | |
| 		return nil, err
 | |
| 	}
 | |
| 	y, err := newCurvePoint(getData(input, 64, 64))
 | |
| 	if err != nil {
 | |
| 		return nil, err
 | |
| 	}
 | |
| 	res := new(bn256.G1)
 | |
| 	res.Add(x, y)
 | |
| 	return res.Marshal(), nil
 | |
| }
 | |
| 
 | |
| // bn256Add implements a native elliptic curve point addition conforming to
 | |
| // Istanbul consensus rules.
 | |
| type bn256AddIstanbul struct{}
 | |
| 
 | |
| // RequiredGas returns the gas required to execute the pre-compiled contract.
 | |
| func (c *bn256AddIstanbul) RequiredGas(input []byte) uint64 {
 | |
| 	return params.Bn256AddGasIstanbul
 | |
| }
 | |
| 
 | |
| func (c *bn256AddIstanbul) Run(input []byte) ([]byte, error) {
 | |
| 	return runBn256Add(input)
 | |
| }
 | |
| 
 | |
| // bn256AddByzantium implements a native elliptic curve point addition
 | |
| // conforming to Byzantium consensus rules.
 | |
| type bn256AddByzantium struct{}
 | |
| 
 | |
| // RequiredGas returns the gas required to execute the pre-compiled contract.
 | |
| func (c *bn256AddByzantium) RequiredGas(input []byte) uint64 {
 | |
| 	return params.Bn256AddGasByzantium
 | |
| }
 | |
| 
 | |
| func (c *bn256AddByzantium) Run(input []byte) ([]byte, error) {
 | |
| 	return runBn256Add(input)
 | |
| }
 | |
| 
 | |
| // runBn256ScalarMul implements the Bn256ScalarMul precompile, referenced by
 | |
| // both Byzantium and Istanbul operations.
 | |
| func runBn256ScalarMul(input []byte) ([]byte, error) {
 | |
| 	p, err := newCurvePoint(getData(input, 0, 64))
 | |
| 	if err != nil {
 | |
| 		return nil, err
 | |
| 	}
 | |
| 	res := new(bn256.G1)
 | |
| 	res.ScalarMult(p, new(big.Int).SetBytes(getData(input, 64, 32)))
 | |
| 	return res.Marshal(), nil
 | |
| }
 | |
| 
 | |
| // bn256ScalarMulIstanbul implements a native elliptic curve scalar
 | |
| // multiplication conforming to Istanbul consensus rules.
 | |
| type bn256ScalarMulIstanbul struct{}
 | |
| 
 | |
| // RequiredGas returns the gas required to execute the pre-compiled contract.
 | |
| func (c *bn256ScalarMulIstanbul) RequiredGas(input []byte) uint64 {
 | |
| 	return params.Bn256ScalarMulGasIstanbul
 | |
| }
 | |
| 
 | |
| func (c *bn256ScalarMulIstanbul) Run(input []byte) ([]byte, error) {
 | |
| 	return runBn256ScalarMul(input)
 | |
| }
 | |
| 
 | |
| // bn256ScalarMulByzantium implements a native elliptic curve scalar
 | |
| // multiplication conforming to Byzantium consensus rules.
 | |
| type bn256ScalarMulByzantium struct{}
 | |
| 
 | |
| // RequiredGas returns the gas required to execute the pre-compiled contract.
 | |
| func (c *bn256ScalarMulByzantium) RequiredGas(input []byte) uint64 {
 | |
| 	return params.Bn256ScalarMulGasByzantium
 | |
| }
 | |
| 
 | |
| func (c *bn256ScalarMulByzantium) Run(input []byte) ([]byte, error) {
 | |
| 	return runBn256ScalarMul(input)
 | |
| }
 | |
| 
 | |
| var (
 | |
| 	// 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")
 | |
| )
 | |
| 
 | |
| // runBn256Pairing implements the Bn256Pairing precompile, referenced by both
 | |
| // Byzantium and Istanbul operations.
 | |
| func runBn256Pairing(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 (
 | |
| 		cs []*bn256.G1
 | |
| 		ts []*bn256.G2
 | |
| 	)
 | |
| 	for i := 0; i < len(input); i += 192 {
 | |
| 		c, err := newCurvePoint(input[i : i+64])
 | |
| 		if err != nil {
 | |
| 			return nil, err
 | |
| 		}
 | |
| 		t, err := newTwistPoint(input[i+64 : i+192])
 | |
| 		if err != nil {
 | |
| 			return nil, err
 | |
| 		}
 | |
| 		cs = append(cs, c)
 | |
| 		ts = append(ts, t)
 | |
| 	}
 | |
| 	// Execute the pairing checks and return the results
 | |
| 	if bn256.PairingCheck(cs, ts) {
 | |
| 		return true32Byte, nil
 | |
| 	}
 | |
| 	return false32Byte, nil
 | |
| }
 | |
| 
 | |
| // bn256PairingIstanbul implements a pairing pre-compile for the bn256 curve
 | |
| // conforming to Istanbul consensus rules.
 | |
| type bn256PairingIstanbul struct{}
 | |
| 
 | |
| // RequiredGas returns the gas required to execute the pre-compiled contract.
 | |
| func (c *bn256PairingIstanbul) RequiredGas(input []byte) uint64 {
 | |
| 	return params.Bn256PairingBaseGasIstanbul + uint64(len(input)/192)*params.Bn256PairingPerPointGasIstanbul
 | |
| }
 | |
| 
 | |
| func (c *bn256PairingIstanbul) Run(input []byte) ([]byte, error) {
 | |
| 	return runBn256Pairing(input)
 | |
| }
 | |
| 
 | |
| // bn256PairingByzantium implements a pairing pre-compile for the bn256 curve
 | |
| // conforming to Byzantium consensus rules.
 | |
| type bn256PairingByzantium struct{}
 | |
| 
 | |
| // RequiredGas returns the gas required to execute the pre-compiled contract.
 | |
| func (c *bn256PairingByzantium) RequiredGas(input []byte) uint64 {
 | |
| 	return params.Bn256PairingBaseGasByzantium + uint64(len(input)/192)*params.Bn256PairingPerPointGasByzantium
 | |
| }
 | |
| 
 | |
| func (c *bn256PairingByzantium) Run(input []byte) ([]byte, error) {
 | |
| 	return runBn256Pairing(input)
 | |
| }
 | |
| 
 | |
| type blake2F struct{}
 | |
| 
 | |
| func (c *blake2F) RequiredGas(input []byte) uint64 {
 | |
| 	// If the input is malformed, we can't calculate the gas, return 0 and let the
 | |
| 	// actual call choke and fault.
 | |
| 	if len(input) != blake2FInputLength {
 | |
| 		return 0
 | |
| 	}
 | |
| 	return uint64(binary.BigEndian.Uint32(input[0:4]))
 | |
| }
 | |
| 
 | |
| const (
 | |
| 	blake2FInputLength        = 213
 | |
| 	blake2FFinalBlockBytes    = byte(1)
 | |
| 	blake2FNonFinalBlockBytes = byte(0)
 | |
| )
 | |
| 
 | |
| var (
 | |
| 	errBlake2FInvalidInputLength = errors.New("invalid input length")
 | |
| 	errBlake2FInvalidFinalFlag   = errors.New("invalid final flag")
 | |
| )
 | |
| 
 | |
| func (c *blake2F) Run(input []byte) ([]byte, error) {
 | |
| 	// Make sure the input is valid (correct lenth and final flag)
 | |
| 	if len(input) != blake2FInputLength {
 | |
| 		return nil, errBlake2FInvalidInputLength
 | |
| 	}
 | |
| 	if input[212] != blake2FNonFinalBlockBytes && input[212] != blake2FFinalBlockBytes {
 | |
| 		return nil, errBlake2FInvalidFinalFlag
 | |
| 	}
 | |
| 	// Parse the input into the Blake2b call parameters
 | |
| 	var (
 | |
| 		rounds = binary.BigEndian.Uint32(input[0:4])
 | |
| 		final  = (input[212] == blake2FFinalBlockBytes)
 | |
| 
 | |
| 		h [8]uint64
 | |
| 		m [16]uint64
 | |
| 		t [2]uint64
 | |
| 	)
 | |
| 	for i := 0; i < 8; i++ {
 | |
| 		offset := 4 + i*8
 | |
| 		h[i] = binary.LittleEndian.Uint64(input[offset : offset+8])
 | |
| 	}
 | |
| 	for i := 0; i < 16; i++ {
 | |
| 		offset := 68 + i*8
 | |
| 		m[i] = binary.LittleEndian.Uint64(input[offset : offset+8])
 | |
| 	}
 | |
| 	t[0] = binary.LittleEndian.Uint64(input[196:204])
 | |
| 	t[1] = binary.LittleEndian.Uint64(input[204:212])
 | |
| 
 | |
| 	// Execute the compression function, extract and return the result
 | |
| 	blake2b.F(&h, m, t, final, rounds)
 | |
| 
 | |
| 	output := make([]byte, 64)
 | |
| 	for i := 0; i < 8; i++ {
 | |
| 		offset := i * 8
 | |
| 		binary.LittleEndian.PutUint64(output[offset:offset+8], h[i])
 | |
| 	}
 | |
| 	return output, nil
 | |
| }
 |