package oracle import ( "sync" "time" "github.com/nspcc-dev/neo-go/pkg/core/state" "github.com/nspcc-dev/neo-go/pkg/core/transaction" "github.com/nspcc-dev/neo-go/pkg/crypto/keys" "github.com/nspcc-dev/neo-go/pkg/io" "github.com/nspcc-dev/neo-go/pkg/smartcontract" "github.com/nspcc-dev/neo-go/pkg/vm/emit" ) type ( incompleteTx struct { sync.RWMutex // isSent is true tx was already broadcasted. isSent bool // attempts is how many times request was processed. attempts int // time is the time when request was last processed. time time.Time // request is oracle request. request *state.OracleRequest // tx is oracle response transaction. tx *transaction.Transaction // sigs contains signature from every oracle node. sigs map[string]*txSignature // backupTx is backup transaction. backupTx *transaction.Transaction // backupSigs contains signatures of backup tx. backupSigs map[string]*txSignature } txSignature struct { // pub is cached public key. pub *keys.PublicKey // ok is true if signature was verified. ok bool // sig is tx signature. sig []byte } ) func newIncompleteTx() *incompleteTx { return &incompleteTx{ sigs: make(map[string]*txSignature), backupSigs: make(map[string]*txSignature), } } func (t *incompleteTx) reverifyTx() { txHash := t.tx.GetSignedHash() backupHash := t.backupTx.GetSignedHash() for pub, sig := range t.sigs { if !sig.ok { sig.ok = sig.pub.Verify(sig.sig, txHash.BytesBE()) if !sig.ok && sig.pub.Verify(sig.sig, backupHash.BytesBE()) { t.backupSigs[pub] = &txSignature{ pub: sig.pub, ok: true, sig: sig.sig, } } } } } func (t *incompleteTx) addResponse(pub *keys.PublicKey, sig []byte, isBackup bool) { tx, sigs := t.tx, t.sigs if isBackup { tx, sigs = t.backupTx, t.backupSigs } sigs[string(pub.Bytes())] = &txSignature{ pub: pub, ok: tx != nil, sig: sig, } } // finalize checks is either main or backup tx has sufficient number of signatures and returns // tx and bool value indicating if it is ready to be broadcasted. func (t *incompleteTx) finalize(oracleNodes keys.PublicKeys, backupOnly bool) (*transaction.Transaction, bool) { if !backupOnly && finalizeTx(oracleNodes, t.tx, t.sigs) { return t.tx, true } return t.backupTx, finalizeTx(oracleNodes, t.backupTx, t.backupSigs) } func finalizeTx(oracleNodes keys.PublicKeys, tx *transaction.Transaction, txSigs map[string]*txSignature) bool { if tx == nil { return false } m := smartcontract.GetDefaultHonestNodeCount(len(oracleNodes)) sigs := make([][]byte, 0, m) for _, pub := range oracleNodes { sig, ok := txSigs[string(pub.Bytes())] if ok && sig.ok { sigs = append(sigs, sig.sig) if len(sigs) == m { break } } } if len(sigs) != m { return false } w := io.NewBufBinWriter() for i := range sigs { emit.Bytes(w.BinWriter, sigs[i]) } tx.Scripts[1].InvocationScript = w.Bytes() return true } func (t *incompleteTx) getRequest() *state.OracleRequest { t.RLock() defer t.RUnlock() return t.request } func (t *incompleteTx) getTime() time.Time { t.RLock() defer t.RUnlock() return t.time }