Commit f193a1b2 authored by George Hotz's avatar George Hotz

importing vm

parent 515f04bd
// Copyright 2017 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 math
import (
"fmt"
"math/bits"
"strconv"
)
// Integer limit values.
const (
MaxInt8 = 1<<7 - 1
MinInt8 = -1 << 7
MaxInt16 = 1<<15 - 1
MinInt16 = -1 << 15
MaxInt32 = 1<<31 - 1
MinInt32 = -1 << 31
MaxInt64 = 1<<63 - 1
MinInt64 = -1 << 63
MaxUint8 = 1<<8 - 1
MaxUint16 = 1<<16 - 1
MaxUint32 = 1<<32 - 1
MaxUint64 = 1<<64 - 1
)
// HexOrDecimal64 marshals uint64 as hex or decimal.
type HexOrDecimal64 uint64
// UnmarshalText implements encoding.TextUnmarshaler.
func (i *HexOrDecimal64) UnmarshalText(input []byte) error {
int, ok := ParseUint64(string(input))
if !ok {
return fmt.Errorf("invalid hex or decimal integer %q", input)
}
*i = HexOrDecimal64(int)
return nil
}
// MarshalText implements encoding.TextMarshaler.
func (i HexOrDecimal64) MarshalText() ([]byte, error) {
return []byte(fmt.Sprintf("%#x", uint64(i))), nil
}
// ParseUint64 parses s as an integer in decimal or hexadecimal syntax.
// Leading zeros are accepted. The empty string parses as zero.
func ParseUint64(s string) (uint64, bool) {
if s == "" {
return 0, true
}
if len(s) >= 2 && (s[:2] == "0x" || s[:2] == "0X") {
v, err := strconv.ParseUint(s[2:], 16, 64)
return v, err == nil
}
v, err := strconv.ParseUint(s, 10, 64)
return v, err == nil
}
// MustParseUint64 parses s as an integer and panics if the string is invalid.
func MustParseUint64(s string) uint64 {
v, ok := ParseUint64(s)
if !ok {
panic("invalid unsigned 64 bit integer: " + s)
}
return v
}
// SafeSub returns x-y and checks for overflow.
func SafeSub(x, y uint64) (uint64, bool) {
diff, borrowOut := bits.Sub64(x, y, 0)
return diff, borrowOut != 0
}
// SafeAdd returns x+y and checks for overflow.
func SafeAdd(x, y uint64) (uint64, bool) {
sum, carryOut := bits.Add64(x, y, 0)
return sum, carryOut != 0
}
// SafeMul returns x*y and checks for overflow.
func SafeMul(x, y uint64) (uint64, bool) {
hi, lo := bits.Mul64(x, y)
return lo, hi != 0
}
......@@ -17,7 +17,12 @@
package core
import (
"fmt"
"github.com/ethereum/go-ethereum/consensus"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/params"
/*"fmt"
"math/big"
......@@ -26,7 +31,6 @@ import (
"github.com/ethereum/go-ethereum/consensus/misc"
"github.com/ethereum/go-ethereum/core/state"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/params"*/)
......@@ -49,7 +53,6 @@ func NewStateProcessor(config *params.ChainConfig, bc *BlockChain, engine consen
}
}
/*
// Process processes the state changes according to the Ethereum rules by running
// the transaction messages using the statedb and applying any rewards to both
// the processor (coinbase) and any included uncles.
......@@ -93,7 +96,7 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
return receipts, allLogs, *usedGas, nil
}
func applyTransaction(msg types.Message, config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, blockNumber *big.Int, blockHash common.Hash, tx *types.Transaction, usedGas *uint64, evm *vm.EVM) (*types.Receipt, error) {
/*func applyTransaction(msg types.Message, config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, blockNumber *big.Int, blockHash common.Hash, tx *types.Transaction, usedGas *uint64, evm *vm.EVM) (*types.Receipt, error) {
// Create a new context to be used in the EVM environment.
txContext := NewEVMTxContext(msg)
evm.Reset(txContext, statedb)
......
// 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
const (
set2BitsMask = uint16(0b1100_0000_0000_0000)
set3BitsMask = uint16(0b1110_0000_0000_0000)
set4BitsMask = uint16(0b1111_0000_0000_0000)
set5BitsMask = uint16(0b1111_1000_0000_0000)
set6BitsMask = uint16(0b1111_1100_0000_0000)
set7BitsMask = uint16(0b1111_1110_0000_0000)
)
// bitvec is a bit vector which maps bytes in a program.
// An unset bit means the byte is an opcode, a set bit means
// it's data (i.e. argument of PUSHxx).
type bitvec []byte
var lookup = [8]byte{
0x80, 0x40, 0x20, 0x10, 0x8, 0x4, 0x2, 0x1,
}
func (bits bitvec) set1(pos uint64) {
bits[pos/8] |= lookup[pos%8]
}
func (bits bitvec) setN(flag uint16, pos uint64) {
a := flag >> (pos % 8)
bits[pos/8] |= byte(a >> 8)
if b := byte(a); b != 0 {
// If the bit-setting affects the neighbouring byte, we can assign - no need to OR it,
// since it's the first write to that byte
bits[pos/8+1] = b
}
}
func (bits bitvec) set8(pos uint64) {
a := byte(0xFF >> (pos % 8))
bits[pos/8] |= a
bits[pos/8+1] = ^a
}
func (bits bitvec) set16(pos uint64) {
a := byte(0xFF >> (pos % 8))
bits[pos/8] |= a
bits[pos/8+1] = 0xFF
bits[pos/8+2] = ^a
}
// codeSegment checks if the position is in a code segment.
func (bits *bitvec) codeSegment(pos uint64) bool {
return ((*bits)[pos/8] & (0x80 >> (pos % 8))) == 0
}
// codeBitmap collects data locations in code.
func codeBitmap(code []byte) bitvec {
// The bitmap is 4 bytes longer than necessary, in case the code
// ends with a PUSH32, the algorithm will push zeroes onto the
// bitvector outside the bounds of the actual code.
bits := make(bitvec, len(code)/8+1+4)
return codeBitmapInternal(code, bits)
}
// codeBitmapInternal is the internal implementation of codeBitmap.
// It exists for the purpose of being able to run benchmark tests
// without dynamic allocations affecting the results.
func codeBitmapInternal(code, bits bitvec) bitvec {
for pc := uint64(0); pc < uint64(len(code)); {
op := OpCode(code[pc])
pc++
if op < PUSH1 || op > PUSH32 {
continue
}
numbits := op - PUSH1 + 1
if numbits >= 8 {
for ; numbits >= 16; numbits -= 16 {
bits.set16(pc)
pc += 16
}
for ; numbits >= 8; numbits -= 8 {
bits.set8(pc)
pc += 8
}
}
switch numbits {
case 1:
bits.set1(pc)
pc += 1
case 2:
bits.setN(set2BitsMask, pc)
pc += 2
case 3:
bits.setN(set3BitsMask, pc)
pc += 3
case 4:
bits.setN(set4BitsMask, pc)
pc += 4
case 5:
bits.setN(set5BitsMask, pc)
pc += 5
case 6:
bits.setN(set6BitsMask, pc)
pc += 6
case 7:
bits.setN(set7BitsMask, pc)
pc += 7
}
}
return bits
}
// 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 (
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
"github.com/holiman/uint256"
)
// calcMemSize64 calculates the required memory size, and returns
// the size and whether the result overflowed uint64
func calcMemSize64(off, l *uint256.Int) (uint64, bool) {
if !l.IsUint64() {
return 0, true
}
return calcMemSize64WithUint(off, l.Uint64())
}
// calcMemSize64WithUint calculates the required memory size, and returns
// the size and whether the result overflowed uint64
// Identical to calcMemSize64, but length is a uint64
func calcMemSize64WithUint(off *uint256.Int, length64 uint64) (uint64, bool) {
// if length is zero, memsize is always zero, regardless of offset
if length64 == 0 {
return 0, false
}
// Check that offset doesn't overflow
offset64, overflow := off.Uint64WithOverflow()
if overflow {
return 0, true
}
val := offset64 + length64
// if value < either of it's parts, then it overflowed
return val, val < offset64
}
// getData returns a slice from the data based on the start and size and pads
// up to size with zero's. This function is overflow safe.
func getData(data []byte, start uint64, size uint64) []byte {
length := uint64(len(data))
if start > length {
start = length
}
end := start + size
if end > length {
end = length
}
return common.RightPadBytes(data[start:end], int(size))
}
// toWordSize returns the ceiled word size required for memory expansion.
func toWordSize(size uint64) uint64 {
if size > math.MaxUint64-31 {
return math.MaxUint64/32 + 1
}
return (size + 31) / 32
}
func allZero(b []byte) bool {
for _, byte := range b {
if byte != 0 {
return false
}
}
return true
}
// Copyright 2015 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 (
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/holiman/uint256"
)
// ContractRef is a reference to the contract's backing object
type ContractRef interface {
Address() common.Address
}
// AccountRef implements ContractRef.
//
// Account references are used during EVM initialisation and
// it's primary use is to fetch addresses. Removing this object
// proves difficult because of the cached jump destinations which
// are fetched from the parent contract (i.e. the caller), which
// is a ContractRef.
type AccountRef common.Address
// Address casts AccountRef to a Address
func (ar AccountRef) Address() common.Address { return (common.Address)(ar) }
// Contract represents an ethereum contract in the state database. It contains
// the contract code, calling arguments. Contract implements ContractRef
type Contract struct {
// CallerAddress is the result of the caller which initialised this
// contract. However when the "call method" is delegated this value
// needs to be initialised to that of the caller's caller.
CallerAddress common.Address
caller ContractRef
self ContractRef
jumpdests map[common.Hash]bitvec // Aggregated result of JUMPDEST analysis.
analysis bitvec // Locally cached result of JUMPDEST analysis
Code []byte
CodeHash common.Hash
CodeAddr *common.Address
Input []byte
Gas uint64
value *big.Int
}
// NewContract returns a new contract environment for the execution of EVM.
func NewContract(caller ContractRef, object ContractRef, value *big.Int, gas uint64) *Contract {
c := &Contract{CallerAddress: caller.Address(), caller: caller, self: object}
if parent, ok := caller.(*Contract); ok {
// Reuse JUMPDEST analysis from parent context if available.
c.jumpdests = parent.jumpdests
} else {
c.jumpdests = make(map[common.Hash]bitvec)
}
// Gas should be a pointer so it can safely be reduced through the run
// This pointer will be off the state transition
c.Gas = gas
// ensures a value is set
c.value = value
return c
}
func (c *Contract) validJumpdest(dest *uint256.Int) bool {
udest, overflow := dest.Uint64WithOverflow()
// PC cannot go beyond len(code) and certainly can't be bigger than 63bits.
// Don't bother checking for JUMPDEST in that case.
if overflow || udest >= uint64(len(c.Code)) {
return false
}
// Only JUMPDESTs allowed for destinations
if OpCode(c.Code[udest]) != JUMPDEST {
return false
}
return c.isCode(udest)
}
// isCode returns true if the provided PC location is an actual opcode, as
// opposed to a data-segment following a PUSHN operation.
func (c *Contract) isCode(udest uint64) bool {
// Do we already have an analysis laying around?
if c.analysis != nil {
return c.analysis.codeSegment(udest)
}
// Do we have a contract hash already?
// If we do have a hash, that means it's a 'regular' contract. For regular
// contracts ( not temporary initcode), we store the analysis in a map
if c.CodeHash != (common.Hash{}) {
// Does parent context have the analysis?
analysis, exist := c.jumpdests[c.CodeHash]
if !exist {
// Do the analysis and save in parent context
// We do not need to store it in c.analysis
analysis = codeBitmap(c.Code)
c.jumpdests[c.CodeHash] = analysis
}
// Also stash it in current contract for faster access
c.analysis = analysis
return analysis.codeSegment(udest)
}
// We don't have the code hash, most likely a piece of initcode not already
// in state trie. In that case, we do an analysis, and save it locally, so
// we don't have to recalculate it for every JUMP instruction in the execution
// However, we don't save it within the parent context
if c.analysis == nil {
c.analysis = codeBitmap(c.Code)
}
return c.analysis.codeSegment(udest)
}
// AsDelegate sets the contract to be a delegate call and returns the current
// contract (for chaining calls)
func (c *Contract) AsDelegate() *Contract {
// NOTE: caller must, at all times be a contract. It should never happen
// that caller is something other than a Contract.
parent := c.caller.(*Contract)
c.CallerAddress = parent.CallerAddress
c.value = parent.value
return c
}
// GetOp returns the n'th element in the contract's byte array
func (c *Contract) GetOp(n uint64) OpCode {
return OpCode(c.GetByte(n))
}
// GetByte returns the n'th byte in the contract's byte array
func (c *Contract) GetByte(n uint64) byte {
if n < uint64(len(c.Code)) {
return c.Code[n]
}
return 0
}
// Caller returns the caller of the contract.
//
// Caller will recursively call caller when the contract is a delegate
// call, including that of caller's caller.
func (c *Contract) Caller() common.Address {
return c.CallerAddress
}
// UseGas attempts the use gas and subtracts it and returns true on success
func (c *Contract) UseGas(gas uint64) (ok bool) {
if c.Gas < gas {
return false
}
c.Gas -= gas
return true
}
// Address returns the contracts address
func (c *Contract) Address() common.Address {
return c.self.Address()
}
// Value returns the contract's value (sent to it from it's caller)
func (c *Contract) Value() *big.Int {
return c.value
}
// SetCallCode sets the code of the contract and address of the backing data
// object
func (c *Contract) SetCallCode(addr *common.Address, hash common.Hash, code []byte) {
c.Code = code
c.CodeHash = hash
c.CodeAddr = addr
}
// SetCodeOptionalHash can be used to provide code, but it's optional to provide hash.
// In case hash is not provided, the jumpdest analysis will not be saved to the parent context
func (c *Contract) SetCodeOptionalHash(addr *common.Address, codeAndHash *codeAndHash) {
c.Code = codeAndHash.code
c.CodeHash = codeAndHash.hash
c.CodeAddr = addr
}
This diff is collapsed.
// 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 (
"errors"
"fmt"
)
// List evm execution errors
var (
ErrOutOfGas = errors.New("out of gas")
ErrCodeStoreOutOfGas = errors.New("contract creation code storage out of gas")
ErrDepth = errors.New("max call depth exceeded")
ErrInsufficientBalance = errors.New("insufficient balance for transfer")
ErrContractAddressCollision = errors.New("contract address collision")
ErrExecutionReverted = errors.New("execution reverted")
ErrMaxCodeSizeExceeded = errors.New("max code size exceeded")
ErrInvalidJump = errors.New("invalid jump destination")
ErrWriteProtection = errors.New("write protection")
ErrReturnDataOutOfBounds = errors.New("return data out of bounds")
ErrGasUintOverflow = errors.New("gas uint64 overflow")
ErrInvalidCode = errors.New("invalid code: must not begin with 0xef")
)
// ErrStackUnderflow wraps an evm error when the items on the stack less
// than the minimal requirement.
type ErrStackUnderflow struct {
stackLen int
required int
}
func (e *ErrStackUnderflow) Error() string {
return fmt.Sprintf("stack underflow (%d <=> %d)", e.stackLen, e.required)
}
// ErrStackOverflow wraps an evm error when the items on the stack exceeds
// the maximum allowance.
type ErrStackOverflow struct {
stackLen int
limit int
}
func (e *ErrStackOverflow) Error() string {
return fmt.Sprintf("stack limit reached %d (%d)", e.stackLen, e.limit)
}
// ErrInvalidOpCode wraps an evm error when an invalid opcode is encountered.
type ErrInvalidOpCode struct {
opcode OpCode
}
func (e *ErrInvalidOpCode) Error() string { return fmt.Sprintf("invalid opcode: %s", e.opcode) }
This diff is collapsed.
// Copyright 2016 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 (
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
)
// StateDB is an EVM database for full state querying.
type StateDB interface {
CreateAccount(common.Address)
SubBalance(common.Address, *big.Int)
AddBalance(common.Address, *big.Int)
GetBalance(common.Address) *big.Int
GetNonce(common.Address) uint64
SetNonce(common.Address, uint64)
GetCodeHash(common.Address) common.Hash
GetCode(common.Address) []byte
SetCode(common.Address, []byte)
GetCodeSize(common.Address) int
AddRefund(uint64)
SubRefund(uint64)
GetRefund() uint64
GetCommittedState(common.Address, common.Hash) common.Hash
GetState(common.Address, common.Hash) common.Hash
SetState(common.Address, common.Hash, common.Hash)
Suicide(common.Address) bool
HasSuicided(common.Address) bool
// Exist reports whether the given account exists in state.
// Notably this should also return true for suicided accounts.
Exist(common.Address) bool
// Empty returns whether the given account is empty. Empty
// is defined according to EIP161 (balance = nonce = code = 0).
Empty(common.Address) bool
PrepareAccessList(sender common.Address, dest *common.Address, precompiles []common.Address, txAccesses types.AccessList)
AddressInAccessList(addr common.Address) bool
SlotInAccessList(addr common.Address, slot common.Hash) (addressOk bool, slotOk bool)
// AddAddressToAccessList adds the given address to the access list. This operation is safe to perform
// even if the feature/fork is not active yet
AddAddressToAccessList(addr common.Address)
// AddSlotToAccessList adds the given (address,slot) to the access list. This operation is safe to perform
// even if the feature/fork is not active yet
AddSlotToAccessList(addr common.Address, slot common.Hash)
RevertToSnapshot(int)
Snapshot() int
AddLog(*types.Log)
AddPreimage(common.Hash, []byte)
ForEachStorage(common.Address, func(common.Hash, common.Hash) bool) error
}
// CallContext provides a basic interface for the EVM calling conventions. The EVM
// depends on this context being implemented for doing subcalls and initialising new EVM contracts.
type CallContext interface {
// Call another contract
Call(env *EVM, me ContractRef, addr common.Address, data []byte, gas, value *big.Int) ([]byte, error)
// Take another's contract code and execute within our own context
CallCode(env *EVM, me ContractRef, addr common.Address, data []byte, gas, value *big.Int) ([]byte, error)
// Same as CallCode except sender and value is propagated from parent to child scope
DelegateCall(env *EVM, me ContractRef, addr common.Address, data []byte, gas *big.Int) ([]byte, error)
// Create a new contract
Create(env *EVM, me ContractRef, data []byte, gas, value *big.Int) ([]byte, common.Address, error)
}
// 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 (
"hash"
"sync/atomic"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
//"github.com/ethereum/go-ethereum/log"
)
// Config are the configuration options for the Interpreter
type Config struct {
Debug bool // Enables debugging
Tracer Tracer // Opcode logger
NoRecursion bool // Disables call, callcode, delegate call and create
NoBaseFee bool // Forces the EIP-1559 baseFee to 0 (needed for 0 price calls)
EnablePreimageRecording bool // Enables recording of SHA3/keccak preimages
JumpTable [256]*operation // EVM instruction table, automatically populated if unset
ExtraEips []int // Additional EIPS that are to be enabled
}
// ScopeContext contains the things that are per-call, such as stack and memory,
// but not transients like pc and gas
type ScopeContext struct {
Memory *Memory
Stack *Stack
Contract *Contract
}
// keccakState wraps sha3.state. In addition to the usual hash methods, it also supports
// Read to get a variable amount of data from the hash state. Read is faster than Sum
// because it doesn't copy the internal state, but also modifies the internal state.
type keccakState interface {
hash.Hash
Read([]byte) (int, error)
}
// EVMInterpreter represents an EVM interpreter
type EVMInterpreter struct {
evm *EVM
cfg Config
hasher keccakState // Keccak256 hasher instance shared across opcodes
hasherBuf common.Hash // Keccak256 hasher result array shared aross opcodes
readOnly bool // Whether to throw on stateful modifications
returnData []byte // Last CALL's return data for subsequent reuse
}
// NewEVMInterpreter returns a new instance of the Interpreter.
func NewEVMInterpreter(evm *EVM, cfg Config) *EVMInterpreter {
// We use the STOP instruction whether to see
// the jump table was initialised. If it was not
// we'll set the default jump table.
if cfg.JumpTable[STOP] == nil {
var jt JumpTable
switch {
case evm.chainRules.IsLondon:
jt = londonInstructionSet
case evm.chainRules.IsBerlin:
jt = berlinInstructionSet
case evm.chainRules.IsIstanbul:
jt = istanbulInstructionSet
case evm.chainRules.IsConstantinople:
jt = constantinopleInstructionSet
case evm.chainRules.IsByzantium:
jt = byzantiumInstructionSet
case evm.chainRules.IsEIP158:
jt = spuriousDragonInstructionSet
case evm.chainRules.IsEIP150:
jt = tangerineWhistleInstructionSet
case evm.chainRules.IsHomestead:
jt = homesteadInstructionSet
default:
jt = frontierInstructionSet
}
for i, eip := range cfg.ExtraEips {
if err := EnableEIP(eip, &jt); err != nil {
// Disable it, so caller can check if it's activated or not
cfg.ExtraEips = append(cfg.ExtraEips[:i], cfg.ExtraEips[i+1:]...)
//log.Error("EIP activation failed", "eip", eip, "error", err)
}
}
cfg.JumpTable = jt
}
return &EVMInterpreter{
evm: evm,
cfg: cfg,
}
}
// Run loops and evaluates the contract's code with the given input data and returns
// the return byte-slice and an error if one occurred.
//
// It's important to note that any errors returned by the interpreter should be
// considered a revert-and-consume-all-gas operation except for
// ErrExecutionReverted which means revert-and-keep-gas-left.
func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (ret []byte, err error) {
// Increment the call depth which is restricted to 1024
in.evm.depth++
defer func() { in.evm.depth-- }()
// Make sure the readOnly is only set if we aren't in readOnly yet.
// This also makes sure that the readOnly flag isn't removed for child calls.
if readOnly && !in.readOnly {
in.readOnly = true
defer func() { in.readOnly = false }()
}
// Reset the previous call's return data. It's unimportant to preserve the old buffer
// as every returning call will return new data anyway.
in.returnData = nil
// Don't bother with the execution if there's no code.
if len(contract.Code) == 0 {
return nil, nil
}
var (
op OpCode // current opcode
mem = NewMemory() // bound memory
stack = newstack() // local stack
callContext = &ScopeContext{
Memory: mem,
Stack: stack,
Contract: contract,
}
// For optimisation reason we're using uint64 as the program counter.
// It's theoretically possible to go above 2^64. The YP defines the PC
// to be uint256. Practically much less so feasible.
pc = uint64(0) // program counter
cost uint64
// copies used by tracer
pcCopy uint64 // needed for the deferred Tracer
gasCopy uint64 // for Tracer to log gas remaining before execution
logged bool // deferred Tracer should ignore already logged steps
res []byte // result of the opcode execution function
)
// Don't move this deferrred function, it's placed before the capturestate-deferred method,
// so that it get's executed _after_: the capturestate needs the stacks before
// they are returned to the pools
defer func() {
returnStack(stack)
}()
contract.Input = input
if in.cfg.Debug {
defer func() {
if err != nil {
if !logged {
in.cfg.Tracer.CaptureState(in.evm, pcCopy, op, gasCopy, cost, callContext, in.returnData, in.evm.depth, err)
} else {
in.cfg.Tracer.CaptureFault(in.evm, pcCopy, op, gasCopy, cost, callContext, in.evm.depth, err)
}
}
}()
}
// The Interpreter main run loop (contextual). This loop runs until either an
// explicit STOP, RETURN or SELFDESTRUCT is executed, an error occurred during
// the execution of one of the operations or until the done flag is set by the
// parent context.
steps := 0
for {
steps++
if steps%1000 == 0 && atomic.LoadInt32(&in.evm.abort) != 0 {
break
}
if in.cfg.Debug {
// Capture pre-execution values for tracing.
logged, pcCopy, gasCopy = false, pc, contract.Gas
}
// Get the operation from the jump table and validate the stack to ensure there are
// enough stack items available to perform the operation.
op = contract.GetOp(pc)
operation := in.cfg.JumpTable[op]
if operation == nil {
return nil, &ErrInvalidOpCode{opcode: op}
}
// Validate stack
if sLen := stack.len(); sLen < operation.minStack {
return nil, &ErrStackUnderflow{stackLen: sLen, required: operation.minStack}
} else if sLen > operation.maxStack {
return nil, &ErrStackOverflow{stackLen: sLen, limit: operation.maxStack}
}
// If the operation is valid, enforce write restrictions
if in.readOnly && in.evm.chainRules.IsByzantium {
// If the interpreter is operating in readonly mode, make sure no
// state-modifying operation is performed. The 3rd stack item
// for a call operation is the value. Transferring value from one
// account to the others means the state is modified and should also
// return with an error.
if operation.writes || (op == CALL && stack.Back(2).Sign() != 0) {
return nil, ErrWriteProtection
}
}
// Static portion of gas
cost = operation.constantGas // For tracing
if !contract.UseGas(operation.constantGas) {
return nil, ErrOutOfGas
}
var memorySize uint64
// calculate the new memory size and expand the memory to fit
// the operation
// Memory check needs to be done prior to evaluating the dynamic gas portion,
// to detect calculation overflows
if operation.memorySize != nil {
memSize, overflow := operation.memorySize(stack)
if overflow {
return nil, ErrGasUintOverflow
}
// memory is expanded in words of 32 bytes. Gas
// is also calculated in words.
if memorySize, overflow = math.SafeMul(toWordSize(memSize), 32); overflow {
return nil, ErrGasUintOverflow
}
}
// Dynamic portion of gas
// consume the gas and return an error if not enough gas is available.
// cost is explicitly set so that the capture state defer method can get the proper cost
if operation.dynamicGas != nil {
var dynamicCost uint64
dynamicCost, err = operation.dynamicGas(in.evm, contract, stack, mem, memorySize)
cost += dynamicCost // total cost, for debug tracing
if err != nil || !contract.UseGas(dynamicCost) {
return nil, ErrOutOfGas
}
}
if memorySize > 0 {
mem.Resize(memorySize)
}
if in.cfg.Debug {
in.cfg.Tracer.CaptureState(in.evm, pc, op, gasCopy, cost, callContext, in.returnData, in.evm.depth, err)
logged = true
}
// execute the operation
res, err = operation.execute(&pc, in, callContext)
// if the operation clears the return data (e.g. it has returning data)
// set the last return to the result of the operation.
if operation.returns {
in.returnData = res
}
switch {
case err != nil:
return nil, err
case operation.reverts:
return res, ErrExecutionReverted
case operation.halts:
return res, nil
case !operation.jumps:
pc++
}
}
return nil, nil
}
This diff is collapsed.
Copyright (c) 2012 The Go Authors. All rights reserved.
Copyright (c) 2018 Péter Szilágyi. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Copyright 2018 Péter Szilágyi. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be found
// in the LICENSE file.
// Package bn256 implements the Optimal Ate pairing over a 256-bit Barreto-Naehrig curve.
package bn256
import bn256 "github.com/ethereum/go-ethereum/crypto/bn256/google"
// G1 is an abstract cyclic group. The zero value is suitable for use as the
// output of an operation, but cannot be used as an input.
type G1 = bn256.G1
// G2 is an abstract cyclic group. The zero value is suitable for use as the
// output of an operation, but cannot be used as an input.
type G2 = bn256.G2
// PairingCheck calculates the Optimal Ate pairing for a set of points.
func PairingCheck(a []*G1, b []*G2) bool {
return bn256.PairingCheck(a, b)
}
This diff is collapsed.
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bn256
import (
"bytes"
"crypto/rand"
"math/big"
"testing"
)
func TestGFp2Invert(t *testing.T) {
pool := new(bnPool)
a := newGFp2(pool)
a.x.SetString("23423492374", 10)
a.y.SetString("12934872398472394827398470", 10)
inv := newGFp2(pool)
inv.Invert(a, pool)
b := newGFp2(pool).Mul(inv, a, pool)
if b.x.Int64() != 0 || b.y.Int64() != 1 {
t.Fatalf("bad result for a^-1*a: %s %s", b.x, b.y)
}
a.Put(pool)
b.Put(pool)
inv.Put(pool)
if c := pool.Count(); c > 0 {
t.Errorf("Pool count non-zero: %d\n", c)
}
}
func isZero(n *big.Int) bool {
return new(big.Int).Mod(n, P).Int64() == 0
}
func isOne(n *big.Int) bool {
return new(big.Int).Mod(n, P).Int64() == 1
}
func TestGFp6Invert(t *testing.T) {
pool := new(bnPool)
a := newGFp6(pool)
a.x.x.SetString("239487238491", 10)
a.x.y.SetString("2356249827341", 10)
a.y.x.SetString("082659782", 10)
a.y.y.SetString("182703523765", 10)
a.z.x.SetString("978236549263", 10)
a.z.y.SetString("64893242", 10)
inv := newGFp6(pool)
inv.Invert(a, pool)
b := newGFp6(pool).Mul(inv, a, pool)
if !isZero(b.x.x) ||
!isZero(b.x.y) ||
!isZero(b.y.x) ||
!isZero(b.y.y) ||
!isZero(b.z.x) ||
!isOne(b.z.y) {
t.Fatalf("bad result for a^-1*a: %s", b)
}
a.Put(pool)
b.Put(pool)
inv.Put(pool)
if c := pool.Count(); c > 0 {
t.Errorf("Pool count non-zero: %d\n", c)
}
}
func TestGFp12Invert(t *testing.T) {
pool := new(bnPool)
a := newGFp12(pool)
a.x.x.x.SetString("239846234862342323958623", 10)
a.x.x.y.SetString("2359862352529835623", 10)
a.x.y.x.SetString("928836523", 10)
a.x.y.y.SetString("9856234", 10)
a.x.z.x.SetString("235635286", 10)
a.x.z.y.SetString("5628392833", 10)
a.y.x.x.SetString("252936598265329856238956532167968", 10)
a.y.x.y.SetString("23596239865236954178968", 10)
a.y.y.x.SetString("95421692834", 10)
a.y.y.y.SetString("236548", 10)
a.y.z.x.SetString("924523", 10)
a.y.z.y.SetString("12954623", 10)
inv := newGFp12(pool)
inv.Invert(a, pool)
b := newGFp12(pool).Mul(inv, a, pool)
if !isZero(b.x.x.x) ||
!isZero(b.x.x.y) ||
!isZero(b.x.y.x) ||
!isZero(b.x.y.y) ||
!isZero(b.x.z.x) ||
!isZero(b.x.z.y) ||
!isZero(b.y.x.x) ||
!isZero(b.y.x.y) ||
!isZero(b.y.y.x) ||
!isZero(b.y.y.y) ||
!isZero(b.y.z.x) ||
!isOne(b.y.z.y) {
t.Fatalf("bad result for a^-1*a: %s", b)
}
a.Put(pool)
b.Put(pool)
inv.Put(pool)
if c := pool.Count(); c > 0 {
t.Errorf("Pool count non-zero: %d\n", c)
}
}
func TestCurveImpl(t *testing.T) {
pool := new(bnPool)
g := &curvePoint{
pool.Get().SetInt64(1),
pool.Get().SetInt64(-2),
pool.Get().SetInt64(1),
pool.Get().SetInt64(0),
}
x := pool.Get().SetInt64(32498273234)
X := newCurvePoint(pool).Mul(g, x, pool)
y := pool.Get().SetInt64(98732423523)
Y := newCurvePoint(pool).Mul(g, y, pool)
s1 := newCurvePoint(pool).Mul(X, y, pool).MakeAffine(pool)
s2 := newCurvePoint(pool).Mul(Y, x, pool).MakeAffine(pool)
if s1.x.Cmp(s2.x) != 0 ||
s2.x.Cmp(s1.x) != 0 {
t.Errorf("DH points don't match: (%s, %s) (%s, %s)", s1.x, s1.y, s2.x, s2.y)
}
pool.Put(x)
X.Put(pool)
pool.Put(y)
Y.Put(pool)
s1.Put(pool)
s2.Put(pool)
g.Put(pool)
if c := pool.Count(); c > 0 {
t.Errorf("Pool count non-zero: %d\n", c)
}
}
func TestOrderG1(t *testing.T) {
g := new(G1).ScalarBaseMult(Order)
if !g.p.IsInfinity() {
t.Error("G1 has incorrect order")
}
one := new(G1).ScalarBaseMult(new(big.Int).SetInt64(1))
g.Add(g, one)
g.p.MakeAffine(nil)
if g.p.x.Cmp(one.p.x) != 0 || g.p.y.Cmp(one.p.y) != 0 {
t.Errorf("1+0 != 1 in G1")
}
}
func TestOrderG2(t *testing.T) {
g := new(G2).ScalarBaseMult(Order)
if !g.p.IsInfinity() {
t.Error("G2 has incorrect order")
}
one := new(G2).ScalarBaseMult(new(big.Int).SetInt64(1))
g.Add(g, one)
g.p.MakeAffine(nil)
if g.p.x.x.Cmp(one.p.x.x) != 0 ||
g.p.x.y.Cmp(one.p.x.y) != 0 ||
g.p.y.x.Cmp(one.p.y.x) != 0 ||
g.p.y.y.Cmp(one.p.y.y) != 0 {
t.Errorf("1+0 != 1 in G2")
}
}
func TestOrderGT(t *testing.T) {
gt := Pair(&G1{curveGen}, &G2{twistGen})
g := new(GT).ScalarMult(gt, Order)
if !g.p.IsOne() {
t.Error("GT has incorrect order")
}
}
func TestBilinearity(t *testing.T) {
for i := 0; i < 2; i++ {
a, p1, _ := RandomG1(rand.Reader)
b, p2, _ := RandomG2(rand.Reader)
e1 := Pair(p1, p2)
e2 := Pair(&G1{curveGen}, &G2{twistGen})
e2.ScalarMult(e2, a)
e2.ScalarMult(e2, b)
minusE2 := new(GT).Neg(e2)
e1.Add(e1, minusE2)
if !e1.p.IsOne() {
t.Fatalf("bad pairing result: %s", e1)
}
}
}
func TestG1Marshal(t *testing.T) {
g := new(G1).ScalarBaseMult(new(big.Int).SetInt64(1))
form := g.Marshal()
_, err := new(G1).Unmarshal(form)
if err != nil {
t.Fatalf("failed to unmarshal")
}
g.ScalarBaseMult(Order)
form = g.Marshal()
g2 := new(G1)
if _, err = g2.Unmarshal(form); err != nil {
t.Fatalf("failed to unmarshal ∞")
}
if !g2.p.IsInfinity() {
t.Fatalf("∞ unmarshaled incorrectly")
}
}
func TestG2Marshal(t *testing.T) {
g := new(G2).ScalarBaseMult(new(big.Int).SetInt64(1))
form := g.Marshal()
_, err := new(G2).Unmarshal(form)
if err != nil {
t.Fatalf("failed to unmarshal")
}
g.ScalarBaseMult(Order)
form = g.Marshal()
g2 := new(G2)
if _, err = g2.Unmarshal(form); err != nil {
t.Fatalf("failed to unmarshal ∞")
}
if !g2.p.IsInfinity() {
t.Fatalf("∞ unmarshaled incorrectly")
}
}
func TestG1Identity(t *testing.T) {
g := new(G1).ScalarBaseMult(new(big.Int).SetInt64(0))
if !g.p.IsInfinity() {
t.Error("failure")
}
}
func TestG2Identity(t *testing.T) {
g := new(G2).ScalarBaseMult(new(big.Int).SetInt64(0))
if !g.p.IsInfinity() {
t.Error("failure")
}
}
func TestTripartiteDiffieHellman(t *testing.T) {
a, _ := rand.Int(rand.Reader, Order)
b, _ := rand.Int(rand.Reader, Order)
c, _ := rand.Int(rand.Reader, Order)
pa := new(G1)
pa.Unmarshal(new(G1).ScalarBaseMult(a).Marshal())
qa := new(G2)
qa.Unmarshal(new(G2).ScalarBaseMult(a).Marshal())
pb := new(G1)
pb.Unmarshal(new(G1).ScalarBaseMult(b).Marshal())
qb := new(G2)
qb.Unmarshal(new(G2).ScalarBaseMult(b).Marshal())
pc := new(G1)
pc.Unmarshal(new(G1).ScalarBaseMult(c).Marshal())
qc := new(G2)
qc.Unmarshal(new(G2).ScalarBaseMult(c).Marshal())
k1 := Pair(pb, qc)
k1.ScalarMult(k1, a)
k1Bytes := k1.Marshal()
k2 := Pair(pc, qa)
k2.ScalarMult(k2, b)
k2Bytes := k2.Marshal()
k3 := Pair(pa, qb)
k3.ScalarMult(k3, c)
k3Bytes := k3.Marshal()
if !bytes.Equal(k1Bytes, k2Bytes) || !bytes.Equal(k2Bytes, k3Bytes) {
t.Errorf("keys didn't agree")
}
}
func BenchmarkPairing(b *testing.B) {
for i := 0; i < b.N; i++ {
Pair(&G1{curveGen}, &G2{twistGen})
}
}
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bn256
import (
"math/big"
)
func bigFromBase10(s string) *big.Int {
n, _ := new(big.Int).SetString(s, 10)
return n
}
// u is the BN parameter that determines the prime.
var u = bigFromBase10("4965661367192848881")
// P is a prime over which we form a basic field: 36u⁴+36u³+24u²+6u+1.
var P = bigFromBase10("21888242871839275222246405745257275088696311157297823662689037894645226208583")
// Order is the number of elements in both G₁ and G₂: 36u⁴+36u³+18u²+6u+1.
// Needs to be highly 2-adic for efficient SNARK key and proof generation.
// Order - 1 = 2^28 * 3^2 * 13 * 29 * 983 * 11003 * 237073 * 405928799 * 1670836401704629 * 13818364434197438864469338081.
// Refer to https://eprint.iacr.org/2013/879.pdf and https://eprint.iacr.org/2013/507.pdf for more information on these parameters.
var Order = bigFromBase10("21888242871839275222246405745257275088548364400416034343698204186575808495617")
// xiToPMinus1Over6 is ξ^((p-1)/6) where ξ = i+9.
var xiToPMinus1Over6 = &gfP2{bigFromBase10("16469823323077808223889137241176536799009286646108169935659301613961712198316"), bigFromBase10("8376118865763821496583973867626364092589906065868298776909617916018768340080")}
// xiToPMinus1Over3 is ξ^((p-1)/3) where ξ = i+9.
var xiToPMinus1Over3 = &gfP2{bigFromBase10("10307601595873709700152284273816112264069230130616436755625194854815875713954"), bigFromBase10("21575463638280843010398324269430826099269044274347216827212613867836435027261")}
// xiToPMinus1Over2 is ξ^((p-1)/2) where ξ = i+9.
var xiToPMinus1Over2 = &gfP2{bigFromBase10("3505843767911556378687030309984248845540243509899259641013678093033130930403"), bigFromBase10("2821565182194536844548159561693502659359617185244120367078079554186484126554")}
// xiToPSquaredMinus1Over3 is ξ^((p²-1)/3) where ξ = i+9.
var xiToPSquaredMinus1Over3 = bigFromBase10("21888242871839275220042445260109153167277707414472061641714758635765020556616")
// xiTo2PSquaredMinus2Over3 is ξ^((2p²-2)/3) where ξ = i+9 (a cubic root of unity, mod p).
var xiTo2PSquaredMinus2Over3 = bigFromBase10("2203960485148121921418603742825762020974279258880205651966")
// xiToPSquaredMinus1Over6 is ξ^((1p²-1)/6) where ξ = i+9 (a cubic root of -1, mod p).
var xiToPSquaredMinus1Over6 = bigFromBase10("21888242871839275220042445260109153167277707414472061641714758635765020556617")
// xiTo2PMinus2Over3 is ξ^((2p-2)/3) where ξ = i+9.
var xiTo2PMinus2Over3 = &gfP2{bigFromBase10("19937756971775647987995932169929341994314640652964949448313374472400716661030"), bigFromBase10("2581911344467009335267311115468803099551665605076196740867805258568234346338")}
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bn256
import (
"math/big"
)
// curvePoint implements the elliptic curve y²=x³+3. Points are kept in
// Jacobian form and t=z² when valid. G₁ is the set of points of this curve on
// GF(p).
type curvePoint struct {
x, y, z, t *big.Int
}
var curveB = new(big.Int).SetInt64(3)
// curveGen is the generator of G₁.
var curveGen = &curvePoint{
new(big.Int).SetInt64(1),
new(big.Int).SetInt64(2),
new(big.Int).SetInt64(1),
new(big.Int).SetInt64(1),
}
func newCurvePoint(pool *bnPool) *curvePoint {
return &curvePoint{
pool.Get(),
pool.Get(),
pool.Get(),
pool.Get(),
}
}
func (c *curvePoint) String() string {
c.MakeAffine(new(bnPool))
return "(" + c.x.String() + ", " + c.y.String() + ")"
}
func (c *curvePoint) Put(pool *bnPool) {
pool.Put(c.x)
pool.Put(c.y)
pool.Put(c.z)
pool.Put(c.t)
}
func (c *curvePoint) Set(a *curvePoint) {
c.x.Set(a.x)
c.y.Set(a.y)
c.z.Set(a.z)
c.t.Set(a.t)
}
// IsOnCurve returns true iff c is on the curve where c must be in affine form.
func (c *curvePoint) IsOnCurve() bool {
yy := new(big.Int).Mul(c.y, c.y)
xxx := new(big.Int).Mul(c.x, c.x)
xxx.Mul(xxx, c.x)
yy.Sub(yy, xxx)
yy.Sub(yy, curveB)
if yy.Sign() < 0 || yy.Cmp(P) >= 0 {
yy.Mod(yy, P)
}
return yy.Sign() == 0
}
func (c *curvePoint) SetInfinity() {
c.z.SetInt64(0)
}
func (c *curvePoint) IsInfinity() bool {
return c.z.Sign() == 0
}
func (c *curvePoint) Add(a, b *curvePoint, pool *bnPool) {
if a.IsInfinity() {
c.Set(b)
return
}
if b.IsInfinity() {
c.Set(a)
return
}
// See http://hyperelliptic.org/EFD/g1p/auto-code/shortw/jacobian-0/addition/add-2007-bl.op3
// Normalize the points by replacing a = [x1:y1:z1] and b = [x2:y2:z2]
// by [u1:s1:z1·z2] and [u2:s2:z1·z2]
// where u1 = x1·z2², s1 = y1·z2³ and u1 = x2·z1², s2 = y2·z1³
z1z1 := pool.Get().Mul(a.z, a.z)
z1z1.Mod(z1z1, P)
z2z2 := pool.Get().Mul(b.z, b.z)
z2z2.Mod(z2z2, P)
u1 := pool.Get().Mul(a.x, z2z2)
u1.Mod(u1, P)
u2 := pool.Get().Mul(b.x, z1z1)
u2.Mod(u2, P)
t := pool.Get().Mul(b.z, z2z2)
t.Mod(t, P)
s1 := pool.Get().Mul(a.y, t)
s1.Mod(s1, P)
t.Mul(a.z, z1z1)
t.Mod(t, P)
s2 := pool.Get().Mul(b.y, t)
s2.Mod(s2, P)
// Compute x = (2h)²(s²-u1-u2)
// where s = (s2-s1)/(u2-u1) is the slope of the line through
// (u1,s1) and (u2,s2). The extra factor 2h = 2(u2-u1) comes from the value of z below.
// This is also:
// 4(s2-s1)² - 4h²(u1+u2) = 4(s2-s1)² - 4h³ - 4h²(2u1)
// = r² - j - 2v
// with the notations below.
h := pool.Get().Sub(u2, u1)
xEqual := h.Sign() == 0
t.Add(h, h)
// i = 4h²
i := pool.Get().Mul(t, t)
i.Mod(i, P)
// j = 4h³
j := pool.Get().Mul(h, i)
j.Mod(j, P)
t.Sub(s2, s1)
yEqual := t.Sign() == 0
if xEqual && yEqual {
c.Double(a, pool)
return
}
r := pool.Get().Add(t, t)
v := pool.Get().Mul(u1, i)
v.Mod(v, P)
// t4 = 4(s2-s1)²
t4 := pool.Get().Mul(r, r)
t4.Mod(t4, P)
t.Add(v, v)
t6 := pool.Get().Sub(t4, j)
c.x.Sub(t6, t)
// Set y = -(2h)³(s1 + s*(x/4h²-u1))
// This is also
// y = - 2·s1·j - (s2-s1)(2x - 2i·u1) = r(v-x) - 2·s1·j
t.Sub(v, c.x) // t7
t4.Mul(s1, j) // t8
t4.Mod(t4, P)
t6.Add(t4, t4) // t9
t4.Mul(r, t) // t10
t4.Mod(t4, P)
c.y.Sub(t4, t6)
// Set z = 2(u2-u1)·z1·z2 = 2h·z1·z2
t.Add(a.z, b.z) // t11
t4.Mul(t, t) // t12
t4.Mod(t4, P)
t.Sub(t4, z1z1) // t13
t4.Sub(t, z2z2) // t14
c.z.Mul(t4, h)
c.z.Mod(c.z, P)
pool.Put(z1z1)
pool.Put(z2z2)
pool.Put(u1)
pool.Put(u2)
pool.Put(t)
pool.Put(s1)
pool.Put(s2)
pool.Put(h)
pool.Put(i)
pool.Put(j)
pool.Put(r)
pool.Put(v)
pool.Put(t4)
pool.Put(t6)
}
func (c *curvePoint) Double(a *curvePoint, pool *bnPool) {
// See http://hyperelliptic.org/EFD/g1p/auto-code/shortw/jacobian-0/doubling/dbl-2009-l.op3
A := pool.Get().Mul(a.x, a.x)
A.Mod(A, P)
B := pool.Get().Mul(a.y, a.y)
B.Mod(B, P)
C_ := pool.Get().Mul(B, B)
C_.Mod(C_, P)
t := pool.Get().Add(a.x, B)
t2 := pool.Get().Mul(t, t)
t2.Mod(t2, P)
t.Sub(t2, A)
t2.Sub(t, C_)
d := pool.Get().Add(t2, t2)
t.Add(A, A)
e := pool.Get().Add(t, A)
f := pool.Get().Mul(e, e)
f.Mod(f, P)
t.Add(d, d)
c.x.Sub(f, t)
t.Add(C_, C_)
t2.Add(t, t)
t.Add(t2, t2)
c.y.Sub(d, c.x)
t2.Mul(e, c.y)
t2.Mod(t2, P)
c.y.Sub(t2, t)
t.Mul(a.y, a.z)
t.Mod(t, P)
c.z.Add(t, t)
pool.Put(A)
pool.Put(B)
pool.Put(C_)
pool.Put(t)
pool.Put(t2)
pool.Put(d)
pool.Put(e)
pool.Put(f)
}
func (c *curvePoint) Mul(a *curvePoint, scalar *big.Int, pool *bnPool) *curvePoint {
sum := newCurvePoint(pool)
sum.SetInfinity()
t := newCurvePoint(pool)
for i := scalar.BitLen(); i >= 0; i-- {
t.Double(sum, pool)
if scalar.Bit(i) != 0 {
sum.Add(t, a, pool)
} else {
sum.Set(t)
}
}
c.Set(sum)
sum.Put(pool)
t.Put(pool)
return c
}
// MakeAffine converts c to affine form and returns c. If c is ∞, then it sets
// c to 0 : 1 : 0.
func (c *curvePoint) MakeAffine(pool *bnPool) *curvePoint {
if words := c.z.Bits(); len(words) == 1 && words[0] == 1 {
return c
}
if c.IsInfinity() {
c.x.SetInt64(0)
c.y.SetInt64(1)
c.z.SetInt64(0)
c.t.SetInt64(0)
return c
}
zInv := pool.Get().ModInverse(c.z, P)
t := pool.Get().Mul(c.y, zInv)
t.Mod(t, P)
zInv2 := pool.Get().Mul(zInv, zInv)
zInv2.Mod(zInv2, P)
c.y.Mul(t, zInv2)
c.y.Mod(c.y, P)
t.Mul(c.x, zInv2)
t.Mod(t, P)
c.x.Set(t)
c.z.SetInt64(1)
c.t.SetInt64(1)
pool.Put(zInv)
pool.Put(t)
pool.Put(zInv2)
return c
}
func (c *curvePoint) Negative(a *curvePoint) {
c.x.Set(a.x)
c.y.Neg(a.y)
c.z.Set(a.z)
c.t.SetInt64(0)
}
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bn256
import (
"crypto/rand"
)
func ExamplePair() {
// This implements the tripartite Diffie-Hellman algorithm from "A One
// Round Protocol for Tripartite Diffie-Hellman", A. Joux.
// http://www.springerlink.com/content/cddc57yyva0hburb/fulltext.pdf
// Each of three parties, a, b and c, generate a private value.
a, _ := rand.Int(rand.Reader, Order)
b, _ := rand.Int(rand.Reader, Order)
c, _ := rand.Int(rand.Reader, Order)
// Then each party calculates g₁ and g₂ times their private value.
pa := new(G1).ScalarBaseMult(a)
qa := new(G2).ScalarBaseMult(a)
pb := new(G1).ScalarBaseMult(b)
qb := new(G2).ScalarBaseMult(b)
pc := new(G1).ScalarBaseMult(c)
qc := new(G2).ScalarBaseMult(c)
// Now each party exchanges its public values with the other two and
// all parties can calculate the shared key.
k1 := Pair(pb, qc)
k1.ScalarMult(k1, a)
k2 := Pair(pc, qa)
k2.ScalarMult(k2, b)
k3 := Pair(pa, qb)
k3.ScalarMult(k3, c)
// k1, k2 and k3 will all be equal.
}
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bn256
// For details of the algorithms used, see "Multiplication and Squaring on
// Pairing-Friendly Fields, Devegili et al.
// http://eprint.iacr.org/2006/471.pdf.
import (
"math/big"
)
// gfP12 implements the field of size p¹² as a quadratic extension of gfP6
// where ω²=τ.
type gfP12 struct {
x, y *gfP6 // value is xω + y
}
func newGFp12(pool *bnPool) *gfP12 {
return &gfP12{newGFp6(pool), newGFp6(pool)}
}
func (e *gfP12) String() string {
return "(" + e.x.String() + "," + e.y.String() + ")"
}
func (e *gfP12) Put(pool *bnPool) {
e.x.Put(pool)
e.y.Put(pool)
}
func (e *gfP12) Set(a *gfP12) *gfP12 {
e.x.Set(a.x)
e.y.Set(a.y)
return e
}
func (e *gfP12) SetZero() *gfP12 {
e.x.SetZero()
e.y.SetZero()
return e
}
func (e *gfP12) SetOne() *gfP12 {
e.x.SetZero()
e.y.SetOne()
return e
}
func (e *gfP12) Minimal() {
e.x.Minimal()
e.y.Minimal()
}
func (e *gfP12) IsZero() bool {
e.Minimal()
return e.x.IsZero() && e.y.IsZero()
}
func (e *gfP12) IsOne() bool {
e.Minimal()
return e.x.IsZero() && e.y.IsOne()
}
func (e *gfP12) Conjugate(a *gfP12) *gfP12 {
e.x.Negative(a.x)
e.y.Set(a.y)
return a
}
func (e *gfP12) Negative(a *gfP12) *gfP12 {
e.x.Negative(a.x)
e.y.Negative(a.y)
return e
}
// Frobenius computes (xω+y)^p = x^p ω·ξ^((p-1)/6) + y^p
func (e *gfP12) Frobenius(a *gfP12, pool *bnPool) *gfP12 {
e.x.Frobenius(a.x, pool)
e.y.Frobenius(a.y, pool)
e.x.MulScalar(e.x, xiToPMinus1Over6, pool)
return e
}
// FrobeniusP2 computes (xω+y)^p² = x^p² ω·ξ^((p²-1)/6) + y^p²
func (e *gfP12) FrobeniusP2(a *gfP12, pool *bnPool) *gfP12 {
e.x.FrobeniusP2(a.x)
e.x.MulGFP(e.x, xiToPSquaredMinus1Over6)
e.y.FrobeniusP2(a.y)
return e
}
func (e *gfP12) Add(a, b *gfP12) *gfP12 {
e.x.Add(a.x, b.x)
e.y.Add(a.y, b.y)
return e
}
func (e *gfP12) Sub(a, b *gfP12) *gfP12 {
e.x.Sub(a.x, b.x)
e.y.Sub(a.y, b.y)
return e
}
func (e *gfP12) Mul(a, b *gfP12, pool *bnPool) *gfP12 {
tx := newGFp6(pool)
tx.Mul(a.x, b.y, pool)
t := newGFp6(pool)
t.Mul(b.x, a.y, pool)
tx.Add(tx, t)
ty := newGFp6(pool)
ty.Mul(a.y, b.y, pool)
t.Mul(a.x, b.x, pool)
t.MulTau(t, pool)
e.y.Add(ty, t)
e.x.Set(tx)
tx.Put(pool)
ty.Put(pool)
t.Put(pool)
return e
}
func (e *gfP12) MulScalar(a *gfP12, b *gfP6, pool *bnPool) *gfP12 {
e.x.Mul(e.x, b, pool)
e.y.Mul(e.y, b, pool)
return e
}
func (c *gfP12) Exp(a *gfP12, power *big.Int, pool *bnPool) *gfP12 {
sum := newGFp12(pool)
sum.SetOne()
t := newGFp12(pool)
for i := power.BitLen() - 1; i >= 0; i-- {
t.Square(sum, pool)
if power.Bit(i) != 0 {
sum.Mul(t, a, pool)
} else {
sum.Set(t)
}
}
c.Set(sum)
sum.Put(pool)
t.Put(pool)
return c
}
func (e *gfP12) Square(a *gfP12, pool *bnPool) *gfP12 {
// Complex squaring algorithm
v0 := newGFp6(pool)
v0.Mul(a.x, a.y, pool)
t := newGFp6(pool)
t.MulTau(a.x, pool)
t.Add(a.y, t)
ty := newGFp6(pool)
ty.Add(a.x, a.y)
ty.Mul(ty, t, pool)
ty.Sub(ty, v0)
t.MulTau(v0, pool)
ty.Sub(ty, t)
e.y.Set(ty)
e.x.Double(v0)
v0.Put(pool)
t.Put(pool)
ty.Put(pool)
return e
}
func (e *gfP12) Invert(a *gfP12, pool *bnPool) *gfP12 {
// See "Implementing cryptographic pairings", M. Scott, section 3.2.
// ftp://136.206.11.249/pub/crypto/pairings.pdf
t1 := newGFp6(pool)
t2 := newGFp6(pool)
t1.Square(a.x, pool)
t2.Square(a.y, pool)
t1.MulTau(t1, pool)
t1.Sub(t2, t1)
t2.Invert(t1, pool)
e.x.Negative(a.x)
e.y.Set(a.y)
e.MulScalar(e, t2, pool)
t1.Put(pool)
t2.Put(pool)
return e
}
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bn256
// For details of the algorithms used, see "Multiplication and Squaring on
// Pairing-Friendly Fields, Devegili et al.
// http://eprint.iacr.org/2006/471.pdf.
import (
"math/big"
)
// gfP2 implements a field of size p² as a quadratic extension of the base
// field where i²=-1.
type gfP2 struct {
x, y *big.Int // value is xi+y.
}
func newGFp2(pool *bnPool) *gfP2 {
return &gfP2{pool.Get(), pool.Get()}
}
func (e *gfP2) String() string {
x := new(big.Int).Mod(e.x, P)
y := new(big.Int).Mod(e.y, P)
return "(" + x.String() + "," + y.String() + ")"
}
func (e *gfP2) Put(pool *bnPool) {
pool.Put(e.x)
pool.Put(e.y)
}
func (e *gfP2) Set(a *gfP2) *gfP2 {
e.x.Set(a.x)
e.y.Set(a.y)
return e
}
func (e *gfP2) SetZero() *gfP2 {
e.x.SetInt64(0)
e.y.SetInt64(0)
return e
}
func (e *gfP2) SetOne() *gfP2 {
e.x.SetInt64(0)
e.y.SetInt64(1)
return e
}
func (e *gfP2) Minimal() {
if e.x.Sign() < 0 || e.x.Cmp(P) >= 0 {
e.x.Mod(e.x, P)
}
if e.y.Sign() < 0 || e.y.Cmp(P) >= 0 {
e.y.Mod(e.y, P)
}
}
func (e *gfP2) IsZero() bool {
return e.x.Sign() == 0 && e.y.Sign() == 0
}
func (e *gfP2) IsOne() bool {
if e.x.Sign() != 0 {
return false
}
words := e.y.Bits()
return len(words) == 1 && words[0] == 1
}
func (e *gfP2) Conjugate(a *gfP2) *gfP2 {
e.y.Set(a.y)
e.x.Neg(a.x)
return e
}
func (e *gfP2) Negative(a *gfP2) *gfP2 {
e.x.Neg(a.x)
e.y.Neg(a.y)
return e
}
func (e *gfP2) Add(a, b *gfP2) *gfP2 {
e.x.Add(a.x, b.x)
e.y.Add(a.y, b.y)
return e
}
func (e *gfP2) Sub(a, b *gfP2) *gfP2 {
e.x.Sub(a.x, b.x)
e.y.Sub(a.y, b.y)
return e
}
func (e *gfP2) Double(a *gfP2) *gfP2 {
e.x.Lsh(a.x, 1)
e.y.Lsh(a.y, 1)
return e
}
func (c *gfP2) Exp(a *gfP2, power *big.Int, pool *bnPool) *gfP2 {
sum := newGFp2(pool)
sum.SetOne()
t := newGFp2(pool)
for i := power.BitLen() - 1; i >= 0; i-- {
t.Square(sum, pool)
if power.Bit(i) != 0 {
sum.Mul(t, a, pool)
} else {
sum.Set(t)
}
}
c.Set(sum)
sum.Put(pool)
t.Put(pool)
return c
}
// See "Multiplication and Squaring in Pairing-Friendly Fields",
// http://eprint.iacr.org/2006/471.pdf
func (e *gfP2) Mul(a, b *gfP2, pool *bnPool) *gfP2 {
tx := pool.Get().Mul(a.x, b.y)
t := pool.Get().Mul(b.x, a.y)
tx.Add(tx, t)
tx.Mod(tx, P)
ty := pool.Get().Mul(a.y, b.y)
t.Mul(a.x, b.x)
ty.Sub(ty, t)
e.y.Mod(ty, P)
e.x.Set(tx)
pool.Put(tx)
pool.Put(ty)
pool.Put(t)
return e
}
func (e *gfP2) MulScalar(a *gfP2, b *big.Int) *gfP2 {
e.x.Mul(a.x, b)
e.y.Mul(a.y, b)
return e
}
// MulXi sets e=ξa where ξ=i+9 and then returns e.
func (e *gfP2) MulXi(a *gfP2, pool *bnPool) *gfP2 {
// (xi+y)(i+3) = (9x+y)i+(9y-x)
tx := pool.Get().Lsh(a.x, 3)
tx.Add(tx, a.x)
tx.Add(tx, a.y)
ty := pool.Get().Lsh(a.y, 3)
ty.Add(ty, a.y)
ty.Sub(ty, a.x)
e.x.Set(tx)
e.y.Set(ty)
pool.Put(tx)
pool.Put(ty)
return e
}
func (e *gfP2) Square(a *gfP2, pool *bnPool) *gfP2 {
// Complex squaring algorithm:
// (xi+b)² = (x+y)(y-x) + 2*i*x*y
t1 := pool.Get().Sub(a.y, a.x)
t2 := pool.Get().Add(a.x, a.y)
ty := pool.Get().Mul(t1, t2)
ty.Mod(ty, P)
t1.Mul(a.x, a.y)
t1.Lsh(t1, 1)
e.x.Mod(t1, P)
e.y.Set(ty)
pool.Put(t1)
pool.Put(t2)
pool.Put(ty)
return e
}
func (e *gfP2) Invert(a *gfP2, pool *bnPool) *gfP2 {
// See "Implementing cryptographic pairings", M. Scott, section 3.2.
// ftp://136.206.11.249/pub/crypto/pairings.pdf
t := pool.Get()
t.Mul(a.y, a.y)
t2 := pool.Get()
t2.Mul(a.x, a.x)
t.Add(t, t2)
inv := pool.Get()
inv.ModInverse(t, P)
e.x.Neg(a.x)
e.x.Mul(e.x, inv)
e.x.Mod(e.x, P)
e.y.Mul(a.y, inv)
e.y.Mod(e.y, P)
pool.Put(t)
pool.Put(t2)
pool.Put(inv)
return e
}
func (e *gfP2) Real() *big.Int {
return e.x
}
func (e *gfP2) Imag() *big.Int {
return e.y
}
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package bn256
// For details of the algorithms used, see "Multiplication and Squaring on
// Pairing-Friendly Fields, Devegili et al.
// http://eprint.iacr.org/2006/471.pdf.
import (
"math/big"
)
// gfP6 implements the field of size p⁶ as a cubic extension of gfP2 where τ³=ξ
// and ξ=i+9.
type gfP6 struct {
x, y, z *gfP2 // value is xτ² + yτ + z
}
func newGFp6(pool *bnPool) *gfP6 {
return &gfP6{newGFp2(pool), newGFp2(pool), newGFp2(pool)}
}
func (e *gfP6) String() string {
return "(" + e.x.String() + "," + e.y.String() + "," + e.z.String() + ")"
}
func (e *gfP6) Put(pool *bnPool) {
e.x.Put(pool)
e.y.Put(pool)
e.z.Put(pool)
}
func (e *gfP6) Set(a *gfP6) *gfP6 {
e.x.Set(a.x)
e.y.Set(a.y)
e.z.Set(a.z)
return e
}
func (e *gfP6) SetZero() *gfP6 {
e.x.SetZero()
e.y.SetZero()
e.z.SetZero()
return e
}
func (e *gfP6) SetOne() *gfP6 {
e.x.SetZero()
e.y.SetZero()
e.z.SetOne()
return e
}
func (e *gfP6) Minimal() {
e.x.Minimal()
e.y.Minimal()
e.z.Minimal()
}
func (e *gfP6) IsZero() bool {
return e.x.IsZero() && e.y.IsZero() && e.z.IsZero()
}
func (e *gfP6) IsOne() bool {
return e.x.IsZero() && e.y.IsZero() && e.z.IsOne()
}
func (e *gfP6) Negative(a *gfP6) *gfP6 {
e.x.Negative(a.x)
e.y.Negative(a.y)
e.z.Negative(a.z)
return e
}
func (e *gfP6) Frobenius(a *gfP6, pool *bnPool) *gfP6 {
e.x.Conjugate(a.x)
e.y.Conjugate(a.y)
e.z.Conjugate(a.z)
e.x.Mul(e.x, xiTo2PMinus2Over3, pool)
e.y.Mul(e.y, xiToPMinus1Over3, pool)
return e
}
// FrobeniusP2 computes (xτ²+yτ+z)^(p²) = xτ^(2p²) + yτ^(p²) + z
func (e *gfP6) FrobeniusP2(a *gfP6) *gfP6 {
// τ^(2p²) = τ²τ^(2p²-2) = τ²ξ^((2p²-2)/3)
e.x.MulScalar(a.x, xiTo2PSquaredMinus2Over3)
// τ^(p²) = ττ^(p²-1) = τξ^((p²-1)/3)
e.y.MulScalar(a.y, xiToPSquaredMinus1Over3)
e.z.Set(a.z)
return e
}
func (e *gfP6) Add(a, b *gfP6) *gfP6 {
e.x.Add(a.x, b.x)
e.y.Add(a.y, b.y)
e.z.Add(a.z, b.z)
return e
}
func (e *gfP6) Sub(a, b *gfP6) *gfP6 {
e.x.Sub(a.x, b.x)
e.y.Sub(a.y, b.y)
e.z.Sub(a.z, b.z)
return e
}
func (e *gfP6) Double(a *gfP6) *gfP6 {
e.x.Double(a.x)
e.y.Double(a.y)
e.z.Double(a.z)
return e
}
func (e *gfP6) Mul(a, b *gfP6, pool *bnPool) *gfP6 {
// "Multiplication and Squaring on Pairing-Friendly Fields"
// Section 4, Karatsuba method.
// http://eprint.iacr.org/2006/471.pdf
v0 := newGFp2(pool)
v0.Mul(a.z, b.z, pool)
v1 := newGFp2(pool)
v1.Mul(a.y, b.y, pool)
v2 := newGFp2(pool)
v2.Mul(a.x, b.x, pool)
t0 := newGFp2(pool)
t0.Add(a.x, a.y)
t1 := newGFp2(pool)
t1.Add(b.x, b.y)
tz := newGFp2(pool)
tz.Mul(t0, t1, pool)
tz.Sub(tz, v1)
tz.Sub(tz, v2)
tz.MulXi(tz, pool)
tz.Add(tz, v0)
t0.Add(a.y, a.z)
t1.Add(b.y, b.z)
ty := newGFp2(pool)
ty.Mul(t0, t1, pool)
ty.Sub(ty, v0)
ty.Sub(ty, v1)
t0.MulXi(v2, pool)
ty.Add(ty, t0)
t0.Add(a.x, a.z)
t1.Add(b.x, b.z)
tx := newGFp2(pool)
tx.Mul(t0, t1, pool)
tx.Sub(tx, v0)
tx.Add(tx, v1)
tx.Sub(tx, v2)
e.x.Set(tx)
e.y.Set(ty)
e.z.Set(tz)
t0.Put(pool)
t1.Put(pool)
tx.Put(pool)
ty.Put(pool)
tz.Put(pool)
v0.Put(pool)
v1.Put(pool)
v2.Put(pool)
return e
}
func (e *gfP6) MulScalar(a *gfP6, b *gfP2, pool *bnPool) *gfP6 {
e.x.Mul(a.x, b, pool)
e.y.Mul(a.y, b, pool)
e.z.Mul(a.z, b, pool)
return e
}
func (e *gfP6) MulGFP(a *gfP6, b *big.Int) *gfP6 {
e.x.MulScalar(a.x, b)
e.y.MulScalar(a.y, b)
e.z.MulScalar(a.z, b)
return e
}
// MulTau computes τ·(aτ²+bτ+c) = bτ²+cτ+aξ
func (e *gfP6) MulTau(a *gfP6, pool *bnPool) {
tz := newGFp2(pool)
tz.MulXi(a.x, pool)
ty := newGFp2(pool)
ty.Set(a.y)
e.y.Set(a.z)
e.x.Set(ty)
e.z.Set(tz)
tz.Put(pool)
ty.Put(pool)
}
func (e *gfP6) Square(a *gfP6, pool *bnPool) *gfP6 {
v0 := newGFp2(pool).Square(a.z, pool)
v1 := newGFp2(pool).Square(a.y, pool)
v2 := newGFp2(pool).Square(a.x, pool)
c0 := newGFp2(pool).Add(a.x, a.y)
c0.Square(c0, pool)
c0.Sub(c0, v1)
c0.Sub(c0, v2)
c0.MulXi(c0, pool)
c0.Add(c0, v0)
c1 := newGFp2(pool).Add(a.y, a.z)
c1.Square(c1, pool)
c1.Sub(c1, v0)
c1.Sub(c1, v1)
xiV2 := newGFp2(pool).MulXi(v2, pool)
c1.Add(c1, xiV2)
c2 := newGFp2(pool).Add(a.x, a.z)
c2.Square(c2, pool)
c2.Sub(c2, v0)
c2.Add(c2, v1)
c2.Sub(c2, v2)
e.x.Set(c2)
e.y.Set(c1)
e.z.Set(c0)
v0.Put(pool)
v1.Put(pool)
v2.Put(pool)
c0.Put(pool)
c1.Put(pool)
c2.Put(pool)
xiV2.Put(pool)
return e
}
func (e *gfP6) Invert(a *gfP6, pool *bnPool) *gfP6 {
// See "Implementing cryptographic pairings", M. Scott, section 3.2.
// ftp://136.206.11.249/pub/crypto/pairings.pdf
// Here we can give a short explanation of how it works: let j be a cubic root of
// unity in GF(p²) so that 1+j+j²=0.
// Then (xτ² + yτ + z)(xj²τ² + yjτ + z)(xjτ² + yj²τ + z)
// = (xτ² + yτ + z)(Cτ²+Bτ+A)
// = (x³ξ²+y³ξ+z³-3ξxyz) = F is an element of the base field (the norm).
//
// On the other hand (xj²τ² + yjτ + z)(xjτ² + yj²τ + z)
// = τ²(y²-ξxz) + τ(ξx²-yz) + (z²-ξxy)
//
// So that's why A = (z²-ξxy), B = (ξx²-yz), C = (y²-ξxz)
t1 := newGFp2(pool)
A := newGFp2(pool)
A.Square(a.z, pool)
t1.Mul(a.x, a.y, pool)
t1.MulXi(t1, pool)
A.Sub(A, t1)
B := newGFp2(pool)
B.Square(a.x, pool)
B.MulXi(B, pool)
t1.Mul(a.y, a.z, pool)
B.Sub(B, t1)
C_ := newGFp2(pool)
C_.Square(a.y, pool)
t1.Mul(a.x, a.z, pool)
C_.Sub(C_, t1)
F := newGFp2(pool)
F.Mul(C_, a.y, pool)
F.MulXi(F, pool)
t1.Mul(A, a.z, pool)
F.Add(F, t1)
t1.Mul(B, a.x, pool)
t1.MulXi(t1, pool)
F.Add(F, t1)
F.Invert(F, pool)
e.x.Mul(C_, F, pool)
e.y.Mul(B, F, pool)
e.z.Mul(A, F, pool)
t1.Put(pool)
A.Put(pool)
B.Put(pool)
C_.Put(pool)
F.Put(pool)
return e
}
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