package consensus import ( "crypto/sha256" "fmt" "github.com/nspcc-dev/dbft/payload" "github.com/nspcc-dev/neo-go/pkg/core" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/crypto/hash" "github.com/nspcc-dev/neo-go/pkg/io" "github.com/nspcc-dev/neo-go/pkg/util" "github.com/nspcc-dev/neo-go/pkg/vm" "github.com/nspcc-dev/neo-go/pkg/vm/opcode" "github.com/pkg/errors" ) type ( messageType byte message struct { Type messageType ViewNumber byte payload io.Serializable } // Payload is a type for consensus-related messages. Payload struct { *message data []byte version uint32 validatorIndex uint16 prevHash util.Uint256 height uint32 Witness transaction.Witness } ) const ( changeViewType messageType = 0x00 prepareRequestType messageType = 0x20 prepareResponseType messageType = 0x21 commitType messageType = 0x30 recoveryRequestType messageType = 0x40 recoveryMessageType messageType = 0x41 ) // ViewNumber implements payload.ConsensusPayload interface. func (p Payload) ViewNumber() byte { return p.message.ViewNumber } // SetViewNumber implements payload.ConsensusPayload interface. func (p *Payload) SetViewNumber(view byte) { p.message.ViewNumber = view } // Type implements payload.ConsensusPayload interface. func (p Payload) Type() payload.MessageType { return payload.MessageType(p.message.Type) } // SetType implements payload.ConsensusPayload interface. func (p *Payload) SetType(t payload.MessageType) { p.message.Type = messageType(t) } // Payload implements payload.ConsensusPayload interface. func (p Payload) Payload() interface{} { return p.payload } // SetPayload implements payload.ConsensusPayload interface. func (p *Payload) SetPayload(pl interface{}) { p.payload = pl.(io.Serializable) } // GetChangeView implements payload.ConsensusPayload interface. func (p Payload) GetChangeView() payload.ChangeView { return p.payload.(payload.ChangeView) } // GetPrepareRequest implements payload.ConsensusPayload interface. func (p Payload) GetPrepareRequest() payload.PrepareRequest { return p.payload.(payload.PrepareRequest) } // GetPrepareResponse implements payload.ConsensusPayload interface. func (p Payload) GetPrepareResponse() payload.PrepareResponse { return p.payload.(payload.PrepareResponse) } // GetCommit implements payload.ConsensusPayload interface. func (p Payload) GetCommit() payload.Commit { return p.payload.(payload.Commit) } // GetRecoveryRequest implements payload.ConsensusPayload interface. func (p Payload) GetRecoveryRequest() payload.RecoveryRequest { return p.payload.(payload.RecoveryRequest) } // GetRecoveryMessage implements payload.ConsensusPayload interface. func (p Payload) GetRecoveryMessage() payload.RecoveryMessage { return p.payload.(payload.RecoveryMessage) } // MarshalUnsigned implements payload.ConsensusPayload interface. func (p Payload) MarshalUnsigned() []byte { w := io.NewBufBinWriter() p.EncodeBinaryUnsigned(w.BinWriter) return w.Bytes() } // UnmarshalUnsigned implements payload.ConsensusPayload interface. func (p *Payload) UnmarshalUnsigned(data []byte) error { r := io.NewBinReaderFromBuf(data) p.DecodeBinaryUnsigned(r) return r.Err } // Version implements payload.ConsensusPayload interface. func (p Payload) Version() uint32 { return p.version } // SetVersion implements payload.ConsensusPayload interface. func (p *Payload) SetVersion(v uint32) { p.version = v } // ValidatorIndex implements payload.ConsensusPayload interface. func (p Payload) ValidatorIndex() uint16 { return p.validatorIndex } // SetValidatorIndex implements payload.ConsensusPayload interface. func (p *Payload) SetValidatorIndex(i uint16) { p.validatorIndex = i } // PrevHash implements payload.ConsensusPayload interface. func (p Payload) PrevHash() util.Uint256 { return p.prevHash } // SetPrevHash implements payload.ConsensusPayload interface. func (p *Payload) SetPrevHash(h util.Uint256) { p.prevHash = h } // Height implements payload.ConsensusPayload interface. func (p Payload) Height() uint32 { return p.height } // SetHeight implements payload.ConsensusPayload interface. func (p *Payload) SetHeight(h uint32) { p.height = h } // EncodeBinaryUnsigned writes payload to w excluding signature. func (p *Payload) EncodeBinaryUnsigned(w *io.BinWriter) { w.WriteU32LE(p.version) w.WriteBytes(p.prevHash[:]) w.WriteU32LE(p.height) w.WriteU16LE(p.validatorIndex) if p.message != nil { ww := io.NewBufBinWriter() p.message.EncodeBinary(ww.BinWriter) p.data = ww.Bytes() } w.WriteVarBytes(p.data) } // EncodeBinary implements io.Serializable interface. func (p *Payload) EncodeBinary(w *io.BinWriter) { p.EncodeBinaryUnsigned(w) w.WriteB(1) p.Witness.EncodeBinary(w) } // Sign signs payload using the private key. // It also sets corresponding verification and invocation scripts. func (p *Payload) Sign(key *privateKey) error { sig, err := key.Sign(p.GetSignedPart()) if err != nil { return err } p.Witness.InvocationScript = append([]byte{byte(opcode.PUSHBYTES64)}, sig...) p.Witness.VerificationScript = key.PublicKey().GetVerificationScript() return nil } // GetSignedPart implements crypto.Verifiable interface. func (p *Payload) GetSignedPart() []byte { return p.MarshalUnsigned() } // Verify verifies payload using provided Witness. func (p *Payload) Verify(scriptHash util.Uint160) bool { verification, err := core.ScriptFromWitness(scriptHash, &p.Witness) if err != nil { return false } v := vm.New() h := sha256.Sum256(p.GetSignedPart()) v.SetCheckedHash(h[:]) v.LoadScript(verification) v.LoadScript(p.Witness.InvocationScript) err = v.Run() if err != nil || v.HasFailed() || v.Estack().Len() != 1 { return false } res, err := v.Estack().Pop().TryBool() return err == nil && res } // DecodeBinaryUnsigned reads payload from w excluding signature. func (p *Payload) DecodeBinaryUnsigned(r *io.BinReader) { p.version = r.ReadU32LE() r.ReadBytes(p.prevHash[:]) p.height = r.ReadU32LE() p.validatorIndex = r.ReadU16LE() p.data = r.ReadVarBytes() if r.Err != nil { return } } // Hash implements payload.ConsensusPayload interface. func (p *Payload) Hash() util.Uint256 { w := io.NewBufBinWriter() p.EncodeBinaryUnsigned(w.BinWriter) if w.Err != nil { panic("failed to hash payload") } return hash.DoubleSha256(w.Bytes()) } // DecodeBinary implements io.Serializable interface. func (p *Payload) DecodeBinary(r *io.BinReader) { p.DecodeBinaryUnsigned(r) if r.Err != nil { return } var b = r.ReadB() if b != 1 { r.Err = errors.New("invalid format") return } p.Witness.DecodeBinary(r) } // EncodeBinary implements io.Serializable interface. func (m *message) EncodeBinary(w *io.BinWriter) { w.WriteBytes([]byte{byte(m.Type)}) w.WriteB(m.ViewNumber) m.payload.EncodeBinary(w) } // DecodeBinary implements io.Serializable interface. func (m *message) DecodeBinary(r *io.BinReader) { m.Type = messageType(r.ReadB()) m.ViewNumber = r.ReadB() switch m.Type { case changeViewType: cv := new(changeView) // newViewNumber is not marshaled cv.newViewNumber = m.ViewNumber + 1 m.payload = cv case prepareRequestType: m.payload = new(prepareRequest) case prepareResponseType: m.payload = new(prepareResponse) case commitType: m.payload = new(commit) case recoveryRequestType: m.payload = new(recoveryRequest) case recoveryMessageType: m.payload = new(recoveryMessage) default: r.Err = errors.Errorf("invalid type: 0x%02x", byte(m.Type)) return } m.payload.DecodeBinary(r) } // String implements fmt.Stringer interface. func (t messageType) String() string { switch t { case changeViewType: return "ChangeView" case prepareRequestType: return "PrepareRequest" case prepareResponseType: return "PrepareResponse" case commitType: return "Commit" case recoveryRequestType: return "RecoveryRequest" case recoveryMessageType: return "RecoveryMessage" default: return fmt.Sprintf("UNKNOWN(0x%02x)", byte(t)) } } // decode data of payload into it's message func (p *Payload) decodeData() error { m := new(message) br := io.NewBinReaderFromBuf(p.data) m.DecodeBinary(br) if br.Err != nil { return errors.Wrap(br.Err, "cannot decode data into message") } p.message = m return nil }