cerc-io/lotus
16
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 27 Wiki Activity

Merge pull request #808 from filecoin-project/patch/fixIsTicketWinner

Browse Source 
fix `IsTicketWinner` in ePoSt
This commit is contained in:
Łukasz Magiera 2019-12-09 18:40:20 +01:00 committed by GitHub
commit 1490cf6b9c
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 34 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
chain/gen/gen.go
View File

@ -526,9 +526,11 @@ func IsRoundWinner(ctx context.Context, ts *types.TipSet, round int64, miner add
return nil, xerrors.Errorf("failed to look up miners sector size: %w", err)
}
snum := types.BigDiv(pow.MinerPower, types.NewInt(ssize))
var winners []sectorbuilder.EPostCandidate
for _, c := range candidates {
if types.IsTicketWinner(c.PartialTicket[:], ssize, pow.TotalPower) {
if types.IsTicketWinner(c.PartialTicket[:], ssize, snum.Uint64(), pow.TotalPower) {
winners = append(winners, c)
}
}

6
chain/sync.go
View File

@ -501,7 +501,7 @@ func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) err
return xerrors.Errorf("received block was from miner slashed at height %d", slashedAt)
}
_, tpow, err := stmgr.GetPower(ctx, syncer.sm, baseTs, h.Miner)
mpow, tpow, err := stmgr.GetPower(ctx, syncer.sm, baseTs, h.Miner)
if err != nil {
return xerrors.Errorf("failed getting power: %w", err)
}
@ -511,8 +511,10 @@ func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) err
return xerrors.Errorf("failed to get sector size for block miner: %w", err)
}
snum := types.BigDiv(mpow, types.NewInt(ssize))
for _, t := range h.EPostProof.Candidates {
if !types.IsTicketWinner(t.Partial, ssize, tpow) {
if !types.IsTicketWinner(t.Partial, ssize, snum.Uint64(), tpow) {
return xerrors.Errorf("miner created a block but was not a winner")
}
}

25
chain/types/blockheader.go
View File

@ -174,9 +174,9 @@ var blocksPerEpoch = NewInt(build.BlocksPerEpoch)
const sha256bits = 256
func IsTicketWinner(partialTicket []byte, ssizeI uint64, totpow BigInt) bool {
func IsTicketWinner(partialTicket []byte, ssizeI uint64, snum uint64, totpow BigInt) bool {
ssize := NewInt(ssizeI)
ssampled := ElectionPostChallengeCount(snum)
/*
Need to check that
(h(vrfout) + 1) / (max(h) + 1) <= e * sectorSize / totalPower
@ -185,23 +185,42 @@ func IsTicketWinner(partialTicket []byte, ssizeI uint64, totpow BigInt) bool {
(h(vrfout) + 1) * totalPower <= e * sectorSize * 2^256
in 2^256 space, it is equivalent to:
h(vrfout) * totalPower < e * sectorSize * 2^256
Because of SectorChallengeRatioDiv sampling for proofs
we need to scale this appropriately.
Let c = ceil(numSectors/SectorChallengeRatioDiv)
(c is the number of tickets a miner requests)
Accordingly we check
(h(vrfout) + 1) / 2^256 <= e * sectorSize / totalPower * snum / c
or
h(vrfout) * totalPower * c < e * sectorSize * 2^256 * snum
*/
h := sha256.Sum256(partialTicket)
lhs := BigFromBytes(h[:]).Int
lhs = lhs.Mul(lhs, totpow.Int)
lhs = lhs.Mul(lhs, new(big.Int).SetUint64(ssampled))
// rhs = sectorSize * 2^256
// rhs = sectorSize << 256
rhs := new(big.Int).Lsh(ssize.Int, sha256bits)
rhs = rhs.Mul(rhs, big.NewInt(build.SectorChallengeRatioDiv))
rhs = rhs.Mul(rhs, new(big.Int).SetUint64(snum))
rhs = rhs.Mul(rhs, blocksPerEpoch.Int)
// h(vrfout) * totalPower < e * sectorSize * 2^256?
return lhs.Cmp(rhs) < 0
}
func ElectionPostChallengeCount(sectors uint64) uint64 {
if sectors == 0 {
return 0
}
// ceil(sectors / build.SectorChallengeRatioDiv)
return (sectors-1)/build.SectorChallengeRatioDiv + 1
}
func (t *Ticket) Equals(ot *Ticket) bool {
return bytes.Equal(t.VRFProof, ot.VRFProof)
}

10
lib/sectorbuilder/sectorbuilder.go
View File

@ -16,6 +16,7 @@ import (
"github.com/filecoin-project/lotus/build"
"github.com/filecoin-project/lotus/chain/address"
"github.com/filecoin-project/lotus/chain/types"
"github.com/filecoin-project/lotus/node/modules/dtypes"
)
@ -623,7 +624,7 @@ func (sb *SectorBuilder) GenerateEPostCandidates(sectorInfo SortedPublicSectorIn
return nil, err
}
challengeCount := ElectionPostChallengeCount(uint64(len(sectorInfo.Values())))
challengeCount := types.ElectionPostChallengeCount(uint64(len(sectorInfo.Values())))
proverID := addressToProverID(sb.Miner)
return sectorbuilder.GenerateCandidates(sb.ssize, proverID, challengeSeed, challengeCount, privsectors)
@ -674,13 +675,8 @@ func (sb *SectorBuilder) Stop() {
close(sb.stopping)
}
func ElectionPostChallengeCount(sectors uint64) uint64 {
// ceil(sectors / build.SectorChallengeRatioDiv)
return (sectors + build.SectorChallengeRatioDiv - 1) / build.SectorChallengeRatioDiv
}
func fallbackPostChallengeCount(sectors uint64) uint64 {
challengeCount := ElectionPostChallengeCount(sectors)
challengeCount := types.ElectionPostChallengeCount(sectors)
if challengeCount > build.MaxFallbackPostChallengeCount {
return build.MaxFallbackPostChallengeCount
}

3
lib/sectorbuilder/simple.go
View File

@ -8,6 +8,7 @@ import (
"go.opencensus.io/trace"
"github.com/filecoin-project/lotus/chain/address"
"github.com/filecoin-project/lotus/chain/types"
)
func (sb *SectorBuilder) SectorSize() uint64 {
@ -36,7 +37,7 @@ func NewSortedPublicSectorInfo(sectors []sectorbuilder.PublicSectorInfo) SortedP
}
func VerifyElectionPost(ctx context.Context, sectorSize uint64, sectorInfo SortedPublicSectorInfo, challengeSeed []byte, proof []byte, candidates []EPostCandidate, proverID address.Address) (bool, error) {
challengeCount := ElectionPostChallengeCount(uint64(len(sectorInfo.Values())))
challengeCount := types.ElectionPostChallengeCount(uint64(len(sectorInfo.Values())))
return verifyPost(ctx, sectorSize, sectorInfo, challengeCount, challengeSeed, proof, candidates, proverID)
}