package vm import ( "bytes" "context" "fmt" goruntime "runtime" "sync" "github.com/filecoin-project/go-address" "github.com/ipfs/go-cid" cbor "github.com/ipfs/go-ipld-cbor" "github.com/minio/blake2b-simd" mh "github.com/multiformats/go-multihash" "golang.org/x/xerrors" "github.com/filecoin-project/lotus/chain/state" "github.com/filecoin-project/lotus/chain/types" "github.com/filecoin-project/lotus/lib/adtutil" "github.com/filecoin-project/lotus/lib/sigs" "github.com/filecoin-project/specs-actors/actors/abi" "github.com/filecoin-project/specs-actors/actors/builtin/miner" "github.com/filecoin-project/specs-actors/actors/crypto" "github.com/filecoin-project/specs-actors/actors/runtime" "github.com/filecoin-project/sector-storage/ffiwrapper" ) func init() { mh.Codes[0xf104] = "filecoin" } // Actual type is defined in chain/types/vmcontext.go because the VMContext interface is there func Syscalls(verifier ffiwrapper.Verifier) runtime.Syscalls { return &syscallShim{verifier: verifier} } type syscallShim struct { ctx context.Context cstate *state.StateTree cst *cbor.BasicIpldStore verifier ffiwrapper.Verifier } func (ss *syscallShim) ComputeUnsealedSectorCID(st abi.RegisteredSealProof, pieces []abi.PieceInfo) (cid.Cid, error) { var sum abi.PaddedPieceSize for _, p := range pieces { sum += p.Size } commd, err := ffiwrapper.GenerateUnsealedCID(st, pieces) if err != nil { log.Errorf("generate data commitment failed: %s", err) return cid.Undef, err } return commd, nil } func (ss *syscallShim) HashBlake2b(data []byte) [32]byte { return blake2b.Sum256(data) } // Checks validity of the submitted consensus fault with the two block headers needed to prove the fault // and an optional extra one to check common ancestry (as needed). // Note that the blocks are ordered: the method requires a.Epoch() <= b.Epoch(). func (ss *syscallShim) VerifyConsensusFault(a, b, extra []byte) (*runtime.ConsensusFault, error) { // Note that block syntax is not validated. Any validly signed block will be accepted pursuant to the below conditions. // Whether or not it could ever have been accepted in a chain is not checked/does not matter here. // for that reason when checking block parent relationships, rather than instantiating a Tipset to do so // (which runs a syntactic check), we do it directly on the CIDs. // (0) cheap preliminary checks // are blocks the same? if bytes.Equal(a, b) { return nil, fmt.Errorf("no consensus fault: submitted blocks are the same") } // can blocks be decoded properly? var blockA, blockB types.BlockHeader if decodeErr := blockA.UnmarshalCBOR(bytes.NewReader(a)); decodeErr != nil { return nil, xerrors.Errorf("cannot decode first block header: %w", decodeErr) } if decodeErr := blockB.UnmarshalCBOR(bytes.NewReader(b)); decodeErr != nil { return nil, xerrors.Errorf("cannot decode second block header: %f", decodeErr) } // (1) check conditions necessary to any consensus fault // were blocks mined by same miner? if blockA.Miner != blockB.Miner { return nil, fmt.Errorf("no consensus fault: blocks not mined by same miner") } // block a must be earlier or equal to block b, epoch wise (ie at least as early in the chain). if blockB.Height < blockA.Height { return nil, fmt.Errorf("first block must not be of higher height than second") } // (2) check for the consensus faults themselves var consensusFault *runtime.ConsensusFault // (a) double-fork mining fault if blockA.Height == blockB.Height { consensusFault = &runtime.ConsensusFault{ Target: blockA.Miner, Epoch: blockB.Height, Type: runtime.ConsensusFaultDoubleForkMining, } } // (b) time-offset mining fault // strictly speaking no need to compare heights based on double fork mining check above, // but at same height this would be a different fault. if types.CidArrsEqual(blockA.Parents, blockB.Parents) && blockA.Height != blockB.Height { consensusFault = &runtime.ConsensusFault{ Target: blockA.Miner, Epoch: blockB.Height, Type: runtime.ConsensusFaultTimeOffsetMining, } } // (c) parent-grinding fault // Here extra is the "witness", a third block that shows the connection between A and B as // A's sibling and B's parent. // Specifically, since A is of lower height, it must be that B was mined omitting A from its tipset var blockC types.BlockHeader if len(extra) > 0 { if decodeErr := blockC.UnmarshalCBOR(bytes.NewReader(extra)); decodeErr != nil { return nil, xerrors.Errorf("cannot decode extra: %w", decodeErr) } if types.CidArrsEqual(blockA.Parents, blockC.Parents) && blockA.Height == blockC.Height && types.CidArrsContains(blockB.Parents, blockC.Cid()) && !types.CidArrsContains(blockB.Parents, blockA.Cid()) { consensusFault = &runtime.ConsensusFault{ Target: blockA.Miner, Epoch: blockB.Height, Type: runtime.ConsensusFaultParentGrinding, } } } // (3) return if no consensus fault by now if consensusFault == nil { return nil, xerrors.Errorf("no consensus fault detected") } // else // (4) expensive final checks // check blocks are properly signed by their respective miner // note we do not need to check extra's: it is a parent to block b // which itself is signed, so it was willingly included by the miner if sigErr := ss.VerifyBlockSig(&blockA); sigErr != nil { return nil, xerrors.Errorf("cannot verify first block sig: %w", sigErr) } if sigErr := ss.VerifyBlockSig(&blockB); sigErr != nil { return nil, xerrors.Errorf("cannot verify second block sig: %w", sigErr) } return consensusFault, nil } func (ss *syscallShim) VerifyBlockSig(blk *types.BlockHeader) error { // get appropriate miner actor act, err := ss.cstate.GetActor(blk.Miner) if err != nil { return err } // use that to get the miner state var mas miner.State if err = ss.cst.Get(ss.ctx, act.Head, &mas); err != nil { return err } info, err := mas.GetInfo(adtutil.NewStore(ss.ctx, ss.cst)) if err != nil { return err } // and use to get resolved workerKey waddr, err := ResolveToKeyAddr(ss.cstate, ss.cst, info.Worker) if err != nil { return err } if err := sigs.CheckBlockSignature(ss.ctx, blk, waddr); err != nil { return err } return nil } func (ss *syscallShim) VerifyPoSt(proof abi.WindowPoStVerifyInfo) error { ok, err := ss.verifier.VerifyWindowPoSt(context.TODO(), proof) if err != nil { return err } if !ok { return fmt.Errorf("proof was invalid") } return nil } func (ss *syscallShim) VerifySeal(info abi.SealVerifyInfo) error { //_, span := trace.StartSpan(ctx, "ValidatePoRep") //defer span.End() miner, err := address.NewIDAddress(uint64(info.Miner)) if err != nil { return xerrors.Errorf("weirdly failed to construct address: %w", err) } ticket := []byte(info.Randomness) proof := info.Proof seed := []byte(info.InteractiveRandomness) log.Debugf("Verif r:%x; d:%x; m:%s; t:%x; s:%x; N:%d; p:%x", info.SealedCID, info.UnsealedCID, miner, ticket, seed, info.SectorID.Number, proof) //func(ctx context.Context, maddr address.Address, ssize abi.SectorSize, commD, commR, ticket, proof, seed []byte, sectorID abi.SectorNumber) ok, err := ss.verifier.VerifySeal(info) if err != nil { return xerrors.Errorf("failed to validate PoRep: %w", err) } if !ok { return fmt.Errorf("invalid proof") } return nil } func (ss *syscallShim) VerifySignature(sig crypto.Signature, addr address.Address, input []byte) error { // TODO: in genesis setup, we are currently faking signatures kaddr, err := ResolveToKeyAddr(ss.cstate, ss.cst, addr) if err != nil { return err } return sigs.Verify(&sig, kaddr, input) } var BatchSealVerifyParallelism = goruntime.NumCPU() func (ss *syscallShim) BatchVerifySeals(inp map[address.Address][]abi.SealVerifyInfo) (map[address.Address][]bool, error) { out := make(map[address.Address][]bool) sema := make(chan struct{}, BatchSealVerifyParallelism) var wg sync.WaitGroup for addr, seals := range inp { results := make([]bool, len(seals)) out[addr] = results for i, s := range seals { wg.Add(1) go func(ma address.Address, ix int, svi abi.SealVerifyInfo, res []bool) { defer wg.Done() sema <- struct{}{} if err := ss.VerifySeal(svi); err != nil { log.Warnw("seal verify in batch failed", "miner", ma, "index", ix, "err", err) res[ix] = false } else { res[ix] = true } <-sema }(addr, i, s, results) } } wg.Wait() return out, nil }