package native import ( "crypto/elliptic" "encoding/binary" "errors" "fmt" "math/big" "sort" "strings" "sync/atomic" "github.com/nspcc-dev/neo-go/pkg/config" "github.com/nspcc-dev/neo-go/pkg/core/dao" "github.com/nspcc-dev/neo-go/pkg/core/interop" "github.com/nspcc-dev/neo-go/pkg/core/interop/runtime" "github.com/nspcc-dev/neo-go/pkg/core/native/nativenames" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/core/storage" "github.com/nspcc-dev/neo-go/pkg/crypto/hash" "github.com/nspcc-dev/neo-go/pkg/crypto/keys" "github.com/nspcc-dev/neo-go/pkg/encoding/bigint" "github.com/nspcc-dev/neo-go/pkg/smartcontract" "github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag" "github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm/stackitem" ) // NEO represents NEO native contract. type NEO struct { nep17TokenNative GAS *GAS // gasPerBlock represents current value of generated gas per block. // It is append-only and doesn't need to be copied when used. gasPerBlock atomic.Value gasPerBlockChanged atomic.Value registerPrice atomic.Value registerPriceChanged atomic.Value votesChanged atomic.Value nextValidators atomic.Value validators atomic.Value // committee contains cached committee members and their votes. // It is updated once in a while depending on committee size // (every 28 blocks for mainnet). It's value // is always equal to value stored by `prefixCommittee`. committee atomic.Value // committeeHash contains script hash of the committee. committeeHash atomic.Value // gasPerVoteCache contains last updated value of GAS per vote reward for candidates. // It is set in state-modifying methods only and read in `PostPersist` thus is not protected // by any mutex. gasPerVoteCache map[string]big.Int // Configuration and standby keys are set during initialization and then // only read from. cfg config.ProtocolConfiguration standbyKeys keys.PublicKeys } const ( neoContractID = -5 // NEOTotalSupply is the total amount of NEO in the system. NEOTotalSupply = 100000000 // DefaultRegisterPrice is default price for candidate register. DefaultRegisterPrice = 1000 * GASFactor // prefixCandidate is a prefix used to store validator's data. prefixCandidate = 33 // prefixVotersCount is a prefix for storing total amount of NEO of voters. prefixVotersCount = 1 // prefixVoterRewardPerCommittee is a prefix for storing committee GAS reward. prefixVoterRewardPerCommittee = 23 // voterRewardFactor is a factor by which voter reward per committee is multiplied // to make calculations more precise. voterRewardFactor = 100_000_000 // prefixGASPerBlock is a prefix for storing amount of GAS generated per block. prefixGASPerBlock = 29 // prefixRegisterPrice is a prefix for storing candidate register price. prefixRegisterPrice = 13 // effectiveVoterTurnout represents minimal ratio of total supply to total amount voted value // which is require to use non-standby validators. effectiveVoterTurnout = 5 // neoHolderRewardRatio is a percent of generated GAS that is distributed to NEO holders. neoHolderRewardRatio = 10 // neoHolderRewardRatio is a percent of generated GAS that is distributed to committee. committeeRewardRatio = 10 // neoHolderRewardRatio is a percent of generated GAS that is distributed to voters. voterRewardRatio = 80 ) var ( // prefixCommittee is a key used to store committee. prefixCommittee = []byte{14} bigCommitteeRewardRatio = big.NewInt(committeeRewardRatio) bigVoterRewardRatio = big.NewInt(voterRewardRatio) bigVoterRewardFactor = big.NewInt(voterRewardFactor) bigEffectiveVoterTurnout = big.NewInt(effectiveVoterTurnout) big100 = big.NewInt(100) ) // makeValidatorKey creates a key from account script hash. func makeValidatorKey(key *keys.PublicKey) []byte { b := key.Bytes() // Don't create a new buffer. b = append(b, 0) copy(b[1:], b[0:]) b[0] = prefixCandidate return b } // newNEO returns NEO native contract. func newNEO() *NEO { n := &NEO{} defer n.UpdateHash() nep17 := newNEP17Native(nativenames.Neo, neoContractID) nep17.symbol = "NEO" nep17.decimals = 0 nep17.factor = 1 nep17.incBalance = n.increaseBalance nep17.balFromBytes = n.balanceFromBytes n.nep17TokenNative = *nep17 n.votesChanged.Store(true) n.nextValidators.Store(keys.PublicKeys(nil)) n.validators.Store(keys.PublicKeys(nil)) n.committee.Store(keysWithVotes(nil)) n.committeeHash.Store(util.Uint160{}) n.registerPriceChanged.Store(true) n.gasPerVoteCache = make(map[string]big.Int) desc := newDescriptor("unclaimedGas", smartcontract.IntegerType, manifest.NewParameter("account", smartcontract.Hash160Type), manifest.NewParameter("end", smartcontract.IntegerType)) md := newMethodAndPrice(n.unclaimedGas, 1<<17, callflag.ReadStates) n.AddMethod(md, desc) desc = newDescriptor("registerCandidate", smartcontract.BoolType, manifest.NewParameter("pubkey", smartcontract.PublicKeyType)) md = newMethodAndPrice(n.registerCandidate, 0, callflag.States) n.AddMethod(md, desc) desc = newDescriptor("unregisterCandidate", smartcontract.BoolType, manifest.NewParameter("pubkey", smartcontract.PublicKeyType)) md = newMethodAndPrice(n.unregisterCandidate, 1<<16, callflag.States) n.AddMethod(md, desc) desc = newDescriptor("vote", smartcontract.BoolType, manifest.NewParameter("account", smartcontract.Hash160Type), manifest.NewParameter("voteTo", smartcontract.PublicKeyType)) md = newMethodAndPrice(n.vote, 1<<16, callflag.States) n.AddMethod(md, desc) desc = newDescriptor("getCandidates", smartcontract.ArrayType) md = newMethodAndPrice(n.getCandidatesCall, 1<<22, callflag.ReadStates) n.AddMethod(md, desc) desc = newDescriptor("getAccountState", smartcontract.ArrayType, manifest.NewParameter("account", smartcontract.Hash160Type)) md = newMethodAndPrice(n.getAccountState, 1<<15, callflag.ReadStates) n.AddMethod(md, desc) desc = newDescriptor("getCommittee", smartcontract.ArrayType) md = newMethodAndPrice(n.getCommittee, 1<<16, callflag.ReadStates) n.AddMethod(md, desc) desc = newDescriptor("getNextBlockValidators", smartcontract.ArrayType) md = newMethodAndPrice(n.getNextBlockValidators, 1<<16, callflag.ReadStates) n.AddMethod(md, desc) desc = newDescriptor("getGasPerBlock", smartcontract.IntegerType) md = newMethodAndPrice(n.getGASPerBlock, 1<<15, callflag.ReadStates) n.AddMethod(md, desc) desc = newDescriptor("setGasPerBlock", smartcontract.VoidType, manifest.NewParameter("gasPerBlock", smartcontract.IntegerType)) md = newMethodAndPrice(n.setGASPerBlock, 1<<15, callflag.States) n.AddMethod(md, desc) desc = newDescriptor("getRegisterPrice", smartcontract.IntegerType) md = newMethodAndPrice(n.getRegisterPrice, 1<<15, callflag.ReadStates) n.AddMethod(md, desc) desc = newDescriptor("setRegisterPrice", smartcontract.VoidType, manifest.NewParameter("registerPrice", smartcontract.IntegerType)) md = newMethodAndPrice(n.setRegisterPrice, 1<<15, callflag.States) n.AddMethod(md, desc) return n } // Initialize initializes NEO contract. func (n *NEO) Initialize(ic *interop.Context) error { err := n.initConfigCache(ic.Chain) if err != nil { return nil } if err := n.nep17TokenNative.Initialize(ic); err != nil { return err } _, totalSupply := n.nep17TokenNative.getTotalSupply(ic.DAO) if totalSupply.Sign() != 0 { return errors.New("already initialized") } committee0 := n.standbyKeys[:n.cfg.GetCommitteeSize(ic.Block.Index)] cvs := toKeysWithVotes(committee0) err = n.updateCache(cvs, ic.Chain) if err != nil { return err } ic.DAO.PutStorageItem(n.ID, prefixCommittee, cvs.Bytes()) h, err := getStandbyValidatorsHash(ic) if err != nil { return err } n.mint(ic, h, big.NewInt(NEOTotalSupply), false) var index uint32 value := big.NewInt(5 * GASFactor) n.putGASRecord(ic.DAO, index, value) gr := &gasRecord{{Index: index, GASPerBlock: *value}} n.gasPerBlock.Store(*gr) n.gasPerBlockChanged.Store(false) ic.DAO.PutStorageItem(n.ID, []byte{prefixVotersCount}, state.StorageItem{}) setIntWithKey(n.ID, ic.DAO, []byte{prefixRegisterPrice}, DefaultRegisterPrice) n.registerPrice.Store(int64(DefaultRegisterPrice)) n.registerPriceChanged.Store(false) return nil } // InitializeCache initializes all NEO cache with the proper values from storage. // Cache initialisation should be done apart from Initialize because Initialize is // called only when deploying native contracts. func (n *NEO) InitializeCache(bc interop.Ledger, d *dao.Simple) error { err := n.initConfigCache(bc) if err != nil { return nil } var committee = keysWithVotes{} si := d.GetStorageItem(n.ID, prefixCommittee) if err := committee.DecodeBytes(si); err != nil { return err } if err := n.updateCache(committee, bc); err != nil { return err } n.gasPerBlock.Store(n.getSortedGASRecordFromDAO(d)) n.gasPerBlockChanged.Store(false) return nil } func (n *NEO) initConfigCache(bc interop.Ledger) error { var err error n.cfg = bc.GetConfig() n.standbyKeys, err = keys.NewPublicKeysFromStrings(n.cfg.StandbyCommittee) return err } func (n *NEO) updateCache(cvs keysWithVotes, bc interop.Ledger) error { n.committee.Store(cvs) var committee = n.GetCommitteeMembers() script, err := smartcontract.CreateMajorityMultiSigRedeemScript(committee.Copy()) if err != nil { return err } n.committeeHash.Store(hash.Hash160(script)) nextVals := committee[:n.cfg.GetNumOfCNs(bc.BlockHeight()+1)].Copy() sort.Sort(nextVals) n.nextValidators.Store(nextVals) return nil } func (n *NEO) updateCommittee(ic *interop.Context) error { votesChanged := n.votesChanged.Load().(bool) if !votesChanged { // We need to put in storage anyway, as it affects dumps committee := n.committee.Load().(keysWithVotes) ic.DAO.PutStorageItem(n.ID, prefixCommittee, committee.Bytes()) return nil } _, cvs, err := n.computeCommitteeMembers(ic.Chain, ic.DAO) if err != nil { return err } if err := n.updateCache(cvs, ic.Chain); err != nil { return err } n.votesChanged.Store(false) ic.DAO.PutStorageItem(n.ID, prefixCommittee, cvs.Bytes()) return nil } // OnPersist implements Contract interface. func (n *NEO) OnPersist(ic *interop.Context) error { if n.cfg.ShouldUpdateCommitteeAt(ic.Block.Index) { oldKeys := n.nextValidators.Load().(keys.PublicKeys) oldCom := n.committee.Load().(keysWithVotes) if n.cfg.GetNumOfCNs(ic.Block.Index) != len(oldKeys) || n.cfg.GetCommitteeSize(ic.Block.Index) != len(oldCom) { n.votesChanged.Store(true) } if err := n.updateCommittee(ic); err != nil { return err } } return nil } // PostPersist implements Contract interface. func (n *NEO) PostPersist(ic *interop.Context) error { gas := n.GetGASPerBlock(ic.DAO, ic.Block.Index) pubs := n.GetCommitteeMembers() committeeSize := n.cfg.GetCommitteeSize(ic.Block.Index) index := int(ic.Block.Index) % committeeSize committeeReward := new(big.Int).Mul(gas, bigCommitteeRewardRatio) n.GAS.mint(ic, pubs[index].GetScriptHash(), committeeReward.Div(committeeReward, big100), false) if n.cfg.ShouldUpdateCommitteeAt(ic.Block.Index) { var voterReward = new(big.Int).Set(bigVoterRewardRatio) voterReward.Mul(voterReward, gas) voterReward.Mul(voterReward, big.NewInt(voterRewardFactor*int64(committeeSize))) var validatorsCount = n.cfg.GetNumOfCNs(ic.Block.Index) voterReward.Div(voterReward, big.NewInt(int64(committeeSize+validatorsCount))) voterReward.Div(voterReward, big100) var cs = n.committee.Load().(keysWithVotes) var key = make([]byte, 38) for i := range cs { if cs[i].Votes.Sign() > 0 { var tmp = new(big.Int) if i < validatorsCount { tmp.Set(intTwo) } else { tmp.Set(intOne) } tmp.Mul(tmp, voterReward) tmp.Div(tmp, cs[i].Votes) key = makeVoterKey([]byte(cs[i].Key), key) var r *big.Int if g, ok := n.gasPerVoteCache[cs[i].Key]; ok { r = &g } else { reward := n.getGASPerVote(ic.DAO, key[:34], []uint32{ic.Block.Index + 1}) r = &reward[0] } tmp.Add(tmp, r) binary.BigEndian.PutUint32(key[34:], ic.Block.Index+1) n.gasPerVoteCache[cs[i].Key] = *tmp ic.DAO.PutStorageItem(n.ID, key, bigint.ToBytes(tmp)) } } } if n.gasPerBlockChanged.Load().(bool) { n.gasPerBlock.Store(n.getSortedGASRecordFromDAO(ic.DAO)) n.gasPerBlockChanged.Store(false) } if n.registerPriceChanged.Load().(bool) { p := getIntWithKey(n.ID, ic.DAO, []byte{prefixRegisterPrice}) n.registerPrice.Store(p) n.registerPriceChanged.Store(false) } return nil } func (n *NEO) getGASPerVote(d *dao.Simple, key []byte, indexes []uint32) []big.Int { sort.Slice(indexes, func(i, j int) bool { return indexes[i] < indexes[j] }) start := make([]byte, 4) binary.BigEndian.PutUint32(start, indexes[len(indexes)-1]) need := len(indexes) var reward = make([]big.Int, need) collected := 0 d.Seek(n.ID, storage.SeekRange{ Prefix: key, Start: start, Backwards: true, }, func(k, v []byte) bool { if len(k) == 4 { num := binary.BigEndian.Uint32(k) for i, ind := range indexes { if reward[i].Sign() == 0 && num <= ind { reward[i] = *bigint.FromBytes(v) collected++ } } } return collected < need }) return reward } func (n *NEO) increaseBalance(ic *interop.Context, h util.Uint160, si *state.StorageItem, amount *big.Int, checkBal *big.Int) error { acc, err := state.NEOBalanceFromBytes(*si) if err != nil { return err } if (amount.Sign() == -1 && acc.Balance.CmpAbs(amount) == -1) || (amount.Sign() == 0 && checkBal != nil && acc.Balance.Cmp(checkBal) == -1) { return errors.New("insufficient funds") } if err := n.distributeGas(ic, h, acc); err != nil { return err } if amount.Sign() == 0 { *si = acc.Bytes() return nil } if err := n.ModifyAccountVotes(acc, ic.DAO, amount, false); err != nil { return err } if acc.VoteTo != nil { if err := n.modifyVoterTurnout(ic.DAO, amount); err != nil { return err } } acc.Balance.Add(&acc.Balance, amount) if acc.Balance.Sign() != 0 { *si = acc.Bytes() } else { *si = nil } return nil } func (n *NEO) balanceFromBytes(si *state.StorageItem) (*big.Int, error) { acc, err := state.NEOBalanceFromBytes(*si) if err != nil { return nil, err } return &acc.Balance, err } func (n *NEO) distributeGas(ic *interop.Context, h util.Uint160, acc *state.NEOBalance) error { if ic.Block == nil || ic.Block.Index == 0 || ic.Block.Index == acc.BalanceHeight { return nil } gen, err := n.calculateBonus(ic.DAO, acc.VoteTo, &acc.Balance, acc.BalanceHeight, ic.Block.Index) if err != nil { return err } acc.BalanceHeight = ic.Block.Index // Must store acc before GAS distribution to fix acc's BalanceHeight value in the storage for // further acc's queries from `onNEP17Payment` if so, see https://github.com/nspcc-dev/neo-go/pull/2181. key := makeAccountKey(h) ic.DAO.PutStorageItem(n.ID, key, acc.Bytes()) n.GAS.mint(ic, h, gen, true) return nil } func (n *NEO) unclaimedGas(ic *interop.Context, args []stackitem.Item) stackitem.Item { u := toUint160(args[0]) end := uint32(toBigInt(args[1]).Int64()) gen, err := n.CalculateBonus(ic.DAO, u, end) if err != nil { panic(err) } return stackitem.NewBigInteger(gen) } func (n *NEO) getGASPerBlock(ic *interop.Context, _ []stackitem.Item) stackitem.Item { gas := n.GetGASPerBlock(ic.DAO, ic.Block.Index) return stackitem.NewBigInteger(gas) } func (n *NEO) getSortedGASRecordFromDAO(d *dao.Simple) gasRecord { var gr = make(gasRecord, 0) d.Seek(n.ID, storage.SeekRange{Prefix: []byte{prefixGASPerBlock}}, func(k, v []byte) bool { gr = append(gr, gasIndexPair{ Index: binary.BigEndian.Uint32(k), GASPerBlock: *bigint.FromBytes(v), }) return true }) return gr } // GetGASPerBlock returns gas generated for block with provided index. func (n *NEO) GetGASPerBlock(d *dao.Simple, index uint32) *big.Int { var gr gasRecord if n.gasPerBlockChanged.Load().(bool) { gr = n.getSortedGASRecordFromDAO(d) } else { gr = n.gasPerBlock.Load().(gasRecord) } for i := len(gr) - 1; i >= 0; i-- { if gr[i].Index <= index { g := gr[i].GASPerBlock return &g } } panic("contract not initialized") } // GetCommitteeAddress returns address of the committee. func (n *NEO) GetCommitteeAddress() util.Uint160 { return n.committeeHash.Load().(util.Uint160) } func (n *NEO) checkCommittee(ic *interop.Context) bool { ok, err := runtime.CheckHashedWitness(ic, n.GetCommitteeAddress()) if err != nil { panic(err) } return ok } func (n *NEO) setGASPerBlock(ic *interop.Context, args []stackitem.Item) stackitem.Item { gas := toBigInt(args[0]) err := n.SetGASPerBlock(ic, ic.Block.Index+1, gas) if err != nil { panic(err) } return stackitem.Null{} } // SetGASPerBlock sets gas generated for blocks after index. func (n *NEO) SetGASPerBlock(ic *interop.Context, index uint32, gas *big.Int) error { if gas.Sign() == -1 || gas.Cmp(big.NewInt(10*GASFactor)) == 1 { return errors.New("invalid value for GASPerBlock") } if !n.checkCommittee(ic) { return errors.New("invalid committee signature") } n.gasPerBlockChanged.Store(true) n.putGASRecord(ic.DAO, index, gas) return nil } func (n *NEO) getRegisterPrice(ic *interop.Context, _ []stackitem.Item) stackitem.Item { return stackitem.NewBigInteger(big.NewInt(n.getRegisterPriceInternal(ic.DAO))) } func (n *NEO) getRegisterPriceInternal(d *dao.Simple) int64 { if !n.registerPriceChanged.Load().(bool) { return n.registerPrice.Load().(int64) } return getIntWithKey(n.ID, d, []byte{prefixRegisterPrice}) } func (n *NEO) setRegisterPrice(ic *interop.Context, args []stackitem.Item) stackitem.Item { price := toBigInt(args[0]) if price.Sign() <= 0 || !price.IsInt64() { panic("invalid register price") } if !n.checkCommittee(ic) { panic("invalid committee signature") } setIntWithKey(n.ID, ic.DAO, []byte{prefixRegisterPrice}, price.Int64()) n.registerPriceChanged.Store(true) return stackitem.Null{} } func (n *NEO) dropCandidateIfZero(d *dao.Simple, pub *keys.PublicKey, c *candidate) (bool, error) { if c.Registered || c.Votes.Sign() != 0 { return false, nil } d.DeleteStorageItem(n.ID, makeValidatorKey(pub)) var toRemove []string voterKey := makeVoterKey(pub.Bytes()) d.Seek(n.ID, storage.SeekRange{Prefix: voterKey}, func(k, v []byte) bool { toRemove = append(toRemove, string(k)) return true }) for i := range toRemove { d.DeleteStorageItem(n.ID, []byte(toRemove[i])) } delete(n.gasPerVoteCache, string(voterKey)) return true, nil } func makeVoterKey(pub []byte, prealloc ...[]byte) []byte { var key []byte if len(prealloc) != 0 { key = prealloc[0] } else { key = make([]byte, 34, 38) } key[0] = prefixVoterRewardPerCommittee copy(key[1:], pub) return key } // CalculateBonus calculates amount of gas generated for holding value NEO from start to end block // and having voted for active committee member. func (n *NEO) CalculateBonus(d *dao.Simple, acc util.Uint160, end uint32) (*big.Int, error) { key := makeAccountKey(acc) si := d.GetStorageItem(n.ID, key) if si == nil { return nil, storage.ErrKeyNotFound } st, err := state.NEOBalanceFromBytes(si) if err != nil { return nil, err } return n.calculateBonus(d, st.VoteTo, &st.Balance, st.BalanceHeight, end) } func (n *NEO) calculateBonus(d *dao.Simple, vote *keys.PublicKey, value *big.Int, start, end uint32) (*big.Int, error) { r, err := n.CalculateNEOHolderReward(d, value, start, end) if err != nil || vote == nil { return r, err } var key = makeVoterKey(vote.Bytes()) var reward = n.getGASPerVote(d, key, []uint32{start, end}) var tmp = (&reward[1]).Sub(&reward[1], &reward[0]) tmp.Mul(tmp, value) tmp.Div(tmp, bigVoterRewardFactor) tmp.Add(tmp, r) return tmp, nil } // CalculateNEOHolderReward return GAS reward for holding `value` of NEO from start to end block. func (n *NEO) CalculateNEOHolderReward(d *dao.Simple, value *big.Int, start, end uint32) (*big.Int, error) { if value.Sign() == 0 || start >= end { return big.NewInt(0), nil } else if value.Sign() < 0 { return nil, errors.New("negative value") } var gr gasRecord if !n.gasPerBlockChanged.Load().(bool) { gr = n.gasPerBlock.Load().(gasRecord) } else { gr = n.getSortedGASRecordFromDAO(d) } var sum, tmp big.Int for i := len(gr) - 1; i >= 0; i-- { if gr[i].Index >= end { continue } else if gr[i].Index <= start { tmp.SetInt64(int64(end - start)) tmp.Mul(&tmp, &gr[i].GASPerBlock) sum.Add(&sum, &tmp) break } tmp.SetInt64(int64(end - gr[i].Index)) tmp.Mul(&tmp, &gr[i].GASPerBlock) sum.Add(&sum, &tmp) end = gr[i].Index } res := new(big.Int).Mul(value, &sum) res.Mul(res, tmp.SetInt64(neoHolderRewardRatio)) res.Div(res, tmp.SetInt64(100*NEOTotalSupply)) return res, nil } func (n *NEO) registerCandidate(ic *interop.Context, args []stackitem.Item) stackitem.Item { pub := toPublicKey(args[0]) ok, err := runtime.CheckKeyedWitness(ic, pub) if err != nil { panic(err) } else if !ok { return stackitem.NewBool(false) } if !ic.VM.AddGas(n.getRegisterPriceInternal(ic.DAO)) { panic("insufficient gas") } err = n.RegisterCandidateInternal(ic, pub) return stackitem.NewBool(err == nil) } // RegisterCandidateInternal registers pub as a new candidate. func (n *NEO) RegisterCandidateInternal(ic *interop.Context, pub *keys.PublicKey) error { key := makeValidatorKey(pub) si := ic.DAO.GetStorageItem(n.ID, key) var c *candidate if si == nil { c = &candidate{Registered: true} } else { c = new(candidate).FromBytes(si) c.Registered = true } return putConvertibleToDAO(n.ID, ic.DAO, key, c) } func (n *NEO) unregisterCandidate(ic *interop.Context, args []stackitem.Item) stackitem.Item { pub := toPublicKey(args[0]) ok, err := runtime.CheckKeyedWitness(ic, pub) if err != nil { panic(err) } else if !ok { return stackitem.NewBool(false) } err = n.UnregisterCandidateInternal(ic, pub) return stackitem.NewBool(err == nil) } // UnregisterCandidateInternal unregisters pub as a candidate. func (n *NEO) UnregisterCandidateInternal(ic *interop.Context, pub *keys.PublicKey) error { key := makeValidatorKey(pub) si := ic.DAO.GetStorageItem(n.ID, key) if si == nil { return nil } n.validators.Store(keys.PublicKeys(nil)) c := new(candidate).FromBytes(si) c.Registered = false ok, err := n.dropCandidateIfZero(ic.DAO, pub, c) if ok { return err } return putConvertibleToDAO(n.ID, ic.DAO, key, c) } func (n *NEO) vote(ic *interop.Context, args []stackitem.Item) stackitem.Item { acc := toUint160(args[0]) var pub *keys.PublicKey if _, ok := args[1].(stackitem.Null); !ok { pub = toPublicKey(args[1]) } err := n.VoteInternal(ic, acc, pub) return stackitem.NewBool(err == nil) } // VoteInternal votes from account h for validarors specified in pubs. func (n *NEO) VoteInternal(ic *interop.Context, h util.Uint160, pub *keys.PublicKey) error { ok, err := runtime.CheckHashedWitness(ic, h) if err != nil { return err } else if !ok { return errors.New("invalid signature") } key := makeAccountKey(h) si := ic.DAO.GetStorageItem(n.ID, key) if si == nil { return errors.New("invalid account") } acc, err := state.NEOBalanceFromBytes(si) if err != nil { return err } // we should put it in storage anyway as it affects dumps ic.DAO.PutStorageItem(n.ID, key, si) if pub != nil { valKey := makeValidatorKey(pub) valSi := ic.DAO.GetStorageItem(n.ID, valKey) if valSi == nil { return errors.New("unknown validator") } cd := new(candidate).FromBytes(valSi) // we should put it in storage anyway as it affects dumps ic.DAO.PutStorageItem(n.ID, valKey, valSi) if !cd.Registered { return errors.New("validator must be registered") } } if (acc.VoteTo == nil) != (pub == nil) { val := &acc.Balance if pub == nil { val = new(big.Int).Neg(val) } if err := n.modifyVoterTurnout(ic.DAO, val); err != nil { return err } } if err := n.distributeGas(ic, h, acc); err != nil { return err } if err := n.ModifyAccountVotes(acc, ic.DAO, new(big.Int).Neg(&acc.Balance), false); err != nil { return err } acc.VoteTo = pub if err := n.ModifyAccountVotes(acc, ic.DAO, &acc.Balance, true); err != nil { return err } ic.DAO.PutStorageItem(n.ID, key, acc.Bytes()) return nil } // ModifyAccountVotes modifies votes of the specified account by value (can be negative). // typ specifies if this modify is occurring during transfer or vote (with old or new validator). func (n *NEO) ModifyAccountVotes(acc *state.NEOBalance, d *dao.Simple, value *big.Int, isNewVote bool) error { n.votesChanged.Store(true) if acc.VoteTo != nil { key := makeValidatorKey(acc.VoteTo) si := d.GetStorageItem(n.ID, key) if si == nil { return errors.New("invalid validator") } cd := new(candidate).FromBytes(si) cd.Votes.Add(&cd.Votes, value) if !isNewVote { ok, err := n.dropCandidateIfZero(d, acc.VoteTo, cd) if ok { return err } } n.validators.Store(keys.PublicKeys(nil)) return putConvertibleToDAO(n.ID, d, key, cd) } return nil } func (n *NEO) getCandidates(d *dao.Simple, sortByKey bool) ([]keyWithVotes, error) { arr := make([]keyWithVotes, 0) d.Seek(n.ID, storage.SeekRange{Prefix: []byte{prefixCandidate}}, func(k, v []byte) bool { c := new(candidate).FromBytes(v) if c.Registered { arr = append(arr, keyWithVotes{Key: string(k), Votes: &c.Votes}) } return true }) if !sortByKey { // sortByKey assumes to sort by serialized key bytes (that's the way keys // are stored and retrieved from the storage by default). Otherwise, need // to sort using big.Int comparator. sort.Slice(arr, func(i, j int) bool { // The most-voted validators should end up in the front of the list. cmp := arr[i].Votes.Cmp(arr[j].Votes) if cmp != 0 { return cmp > 0 } // Ties are broken with deserialized public keys. // Sort by ECPoint's (X, Y) components: compare X first, and then compare Y. cmpX := strings.Compare(arr[i].Key[1:], arr[j].Key[1:]) if cmpX != 0 { return cmpX == -1 } // The case when X components are the same is extremely rare, thus we perform // key deserialization only if needed. No error can occur. ki, _ := keys.NewPublicKeyFromBytes([]byte(arr[i].Key), elliptic.P256()) kj, _ := keys.NewPublicKeyFromBytes([]byte(arr[j].Key), elliptic.P256()) return ki.Y.Cmp(kj.Y) == -1 }) } return arr, nil } // GetCandidates returns current registered validators list with keys // and votes. func (n *NEO) GetCandidates(d *dao.Simple) ([]state.Validator, error) { kvs, err := n.getCandidates(d, true) if err != nil { return nil, err } arr := make([]state.Validator, len(kvs)) for i := range kvs { arr[i].Key, err = keys.NewPublicKeyFromBytes([]byte(kvs[i].Key), elliptic.P256()) if err != nil { return nil, err } arr[i].Votes = kvs[i].Votes } return arr, nil } func (n *NEO) getCandidatesCall(ic *interop.Context, _ []stackitem.Item) stackitem.Item { validators, err := n.getCandidates(ic.DAO, true) if err != nil { panic(err) } arr := make([]stackitem.Item, len(validators)) for i := range validators { arr[i] = stackitem.NewStruct([]stackitem.Item{ stackitem.NewByteArray([]byte(validators[i].Key)), stackitem.NewBigInteger(validators[i].Votes), }) } return stackitem.NewArray(arr) } func (n *NEO) getAccountState(ic *interop.Context, args []stackitem.Item) stackitem.Item { key := makeAccountKey(toUint160(args[0])) si := ic.DAO.GetStorageItem(n.ID, key) if len(si) == 0 { return stackitem.Null{} } item, err := stackitem.Deserialize(si) if err != nil { panic(err) // no errors are expected but we better be sure } return item } // ComputeNextBlockValidators returns an actual list of current validators. func (n *NEO) ComputeNextBlockValidators(bc interop.Ledger, d *dao.Simple) (keys.PublicKeys, error) { numOfCNs := n.cfg.GetNumOfCNs(bc.BlockHeight() + 1) if vals := n.validators.Load().(keys.PublicKeys); vals != nil && numOfCNs == len(vals) { return vals.Copy(), nil } result, _, err := n.computeCommitteeMembers(bc, d) if err != nil { return nil, err } result = result[:numOfCNs] sort.Sort(result) n.validators.Store(result) return result, nil } func (n *NEO) getCommittee(ic *interop.Context, _ []stackitem.Item) stackitem.Item { pubs := n.GetCommitteeMembers() sort.Sort(pubs) return pubsToArray(pubs) } func (n *NEO) modifyVoterTurnout(d *dao.Simple, amount *big.Int) error { key := []byte{prefixVotersCount} si := d.GetStorageItem(n.ID, key) if si == nil { return errors.New("voters count not found") } votersCount := bigint.FromBytes(si) votersCount.Add(votersCount, amount) si = bigint.ToPreallocatedBytes(votersCount, si) d.PutStorageItem(n.ID, key, si) return nil } // GetCommitteeMembers returns public keys of nodes in committee using cached value. func (n *NEO) GetCommitteeMembers() keys.PublicKeys { var cvs = n.committee.Load().(keysWithVotes) var committee = make(keys.PublicKeys, len(cvs)) var err error for i := range committee { committee[i], err = cvs[i].PublicKey() if err != nil { panic(err) } } return committee } func toKeysWithVotes(pubs keys.PublicKeys) keysWithVotes { ks := make(keysWithVotes, len(pubs)) for i := range pubs { ks[i].UnmarshaledKey = pubs[i] ks[i].Key = string(pubs[i].Bytes()) ks[i].Votes = big.NewInt(0) } return ks } // computeCommitteeMembers returns public keys of nodes in committee. func (n *NEO) computeCommitteeMembers(bc interop.Ledger, d *dao.Simple) (keys.PublicKeys, keysWithVotes, error) { key := []byte{prefixVotersCount} si := d.GetStorageItem(n.ID, key) if si == nil { return nil, nil, errors.New("voters count not found") } votersCount := bigint.FromBytes(si) // votersCount / totalSupply must be >= 0.2 votersCount.Mul(votersCount, bigEffectiveVoterTurnout) _, totalSupply := n.getTotalSupply(d) voterTurnout := votersCount.Div(votersCount, totalSupply) count := n.cfg.GetCommitteeSize(bc.BlockHeight() + 1) // Can be sorted and/or returned to outside users, thus needs to be copied. sbVals := keys.PublicKeys(n.standbyKeys[:count]).Copy() cs, err := n.getCandidates(d, false) if err != nil { return nil, nil, err } if voterTurnout.Sign() != 1 || len(cs) < count { kvs := make(keysWithVotes, count) for i := range kvs { kvs[i].UnmarshaledKey = sbVals[i] kvs[i].Key = string(sbVals[i].Bytes()) votes := big.NewInt(0) for j := range cs { if cs[j].Key == kvs[i].Key { votes = cs[j].Votes break } } kvs[i].Votes = votes } return sbVals, kvs, nil } pubs := make(keys.PublicKeys, count) for i := range pubs { pubs[i], err = cs[i].PublicKey() if err != nil { return nil, nil, err } } return pubs, cs[:count], nil } func (n *NEO) getNextBlockValidators(ic *interop.Context, _ []stackitem.Item) stackitem.Item { result := n.GetNextBlockValidatorsInternal() return pubsToArray(result) } // GetNextBlockValidatorsInternal returns next block validators. func (n *NEO) GetNextBlockValidatorsInternal() keys.PublicKeys { return n.nextValidators.Load().(keys.PublicKeys).Copy() } // BalanceOf returns native NEO token balance for the acc. func (n *NEO) BalanceOf(d *dao.Simple, acc util.Uint160) (*big.Int, uint32) { key := makeAccountKey(acc) si := d.GetStorageItem(n.ID, key) if si == nil { return big.NewInt(0), 0 } st, err := state.NEOBalanceFromBytes(si) if err != nil { panic(fmt.Errorf("failed to decode NEO balance state: %w", err)) } return &st.Balance, st.BalanceHeight } func pubsToArray(pubs keys.PublicKeys) stackitem.Item { arr := make([]stackitem.Item, len(pubs)) for i := range pubs { arr[i] = stackitem.NewByteArray(pubs[i].Bytes()) } return stackitem.NewArray(arr) } func toPublicKey(s stackitem.Item) *keys.PublicKey { buf, err := s.TryBytes() if err != nil { panic(err) } pub := new(keys.PublicKey) if err := pub.DecodeBytes(buf); err != nil { panic(err) } return pub } // putGASRecord is a helper which creates key and puts GASPerBlock value into the storage. func (n *NEO) putGASRecord(dao *dao.Simple, index uint32, value *big.Int) { key := make([]byte, 5) key[0] = prefixGASPerBlock binary.BigEndian.PutUint32(key[1:], index) dao.PutStorageItem(n.ID, key, bigint.ToBytes(value)) }