package prover import ( "context" "encoding/json" "fmt" "math/big" "net/http" "strings" "time" "github.com/dghubble/sling" "github.com/hermeznetwork/hermez-node/common" "github.com/hermeznetwork/tracerr" ) // Proof TBD this type will be received from the proof server type Proof struct { PiA [3]*big.Int `json:"pi_a"` PiB [3][2]*big.Int `json:"pi_b"` PiC [3]*big.Int `json:"pi_c"` Protocol string `json:"protocol"` } type bigInt big.Int func (b *bigInt) UnmarshalText(text []byte) error { _, ok := (*big.Int)(b).SetString(string(text), 10) if !ok { return tracerr.Wrap(fmt.Errorf("invalid big int: \"%v\"", string(text))) } return nil } // UnmarshalJSON unmarshals the proof from a JSON encoded proof with the big // ints as strings func (p *Proof) UnmarshalJSON(data []byte) error { proof := struct { PiA [3]*bigInt `json:"pi_a"` PiB [3][2]*bigInt `json:"pi_b"` PiC [3]*bigInt `json:"pi_c"` Protocol string `json:"protocol"` }{} if err := json.Unmarshal(data, &proof); err != nil { return tracerr.Wrap(err) } p.PiA[0] = (*big.Int)(proof.PiA[0]) p.PiA[1] = (*big.Int)(proof.PiA[1]) p.PiA[2] = (*big.Int)(proof.PiA[2]) if p.PiA[2].Int64() != 1 { return fmt.Errorf("Expected PiA[2] == 1, but got %v", p.PiA[2]) } p.PiB[0][0] = (*big.Int)(proof.PiB[0][0]) p.PiB[0][1] = (*big.Int)(proof.PiB[0][1]) p.PiB[1][0] = (*big.Int)(proof.PiB[1][0]) p.PiB[1][1] = (*big.Int)(proof.PiB[1][1]) p.PiB[2][0] = (*big.Int)(proof.PiB[2][0]) p.PiB[2][1] = (*big.Int)(proof.PiB[2][1]) if p.PiB[2][0].Int64() != 1 || p.PiB[2][1].Int64() != 0 { return fmt.Errorf("Expected PiB[2] == [1, 0], but got %v", p.PiB[2]) } p.PiC[0] = (*big.Int)(proof.PiC[0]) p.PiC[1] = (*big.Int)(proof.PiC[1]) p.PiC[2] = (*big.Int)(proof.PiC[2]) if p.PiC[2].Int64() != 1 { return fmt.Errorf("Expected PiC[2] == 1, but got %v", p.PiC[2]) } // TODO: Assert ones and zeroes p.Protocol = proof.Protocol return nil } // PublicInputs are the public inputs of the proof type PublicInputs []*big.Int // UnmarshalJSON unmarshals the JSON into the public inputs where the bigInts // are in decimal as quoted strings func (p *PublicInputs) UnmarshalJSON(data []byte) error { pubInputs := []*bigInt{} if err := json.Unmarshal(data, &pubInputs); err != nil { return tracerr.Wrap(err) } *p = make([]*big.Int, len(pubInputs)) for i, v := range pubInputs { ([]*big.Int)(*p)[i] = (*big.Int)(v) } return nil } // Client is the interface to a ServerProof that calculates zk proofs type Client interface { // Non-blocking CalculateProof(ctx context.Context, zkInputs *common.ZKInputs) error // Blocking. Returns the Proof and Public Data (public inputs) GetProof(ctx context.Context) (*Proof, []*big.Int, error) // Non-Blocking Cancel(ctx context.Context) error // Blocking WaitReady(ctx context.Context) error } // StatusCode is the status string of the ProofServer type StatusCode string const ( // StatusCodeAborted means prover is ready to take new proof. Previous // proof was aborted. StatusCodeAborted StatusCode = "aborted" // StatusCodeBusy means prover is busy computing proof. StatusCodeBusy StatusCode = "busy" // StatusCodeFailed means prover is ready to take new proof. Previous // proof failed StatusCodeFailed StatusCode = "failed" // StatusCodeSuccess means prover is ready to take new proof. Previous // proof succeeded StatusCodeSuccess StatusCode = "success" // StatusCodeUnverified means prover is ready to take new proof. // Previous proof was unverified StatusCodeUnverified StatusCode = "unverified" // StatusCodeUninitialized means prover is not initialized StatusCodeUninitialized StatusCode = "uninitialized" // StatusCodeUndefined means prover is in an undefined state. Most // likely is booting up. Keep trying StatusCodeUndefined StatusCode = "undefined" // StatusCodeInitializing means prover is initializing and not ready yet StatusCodeInitializing StatusCode = "initializing" // StatusCodeReady means prover initialized and ready to do first proof StatusCodeReady StatusCode = "ready" ) // IsReady returns true when the prover is ready func (status StatusCode) IsReady() bool { if status == StatusCodeAborted || status == StatusCodeFailed || status == StatusCodeSuccess || status == StatusCodeUnverified || status == StatusCodeReady { return true } return false } // IsInitialized returns true when the prover is initialized func (status StatusCode) IsInitialized() bool { if status == StatusCodeUninitialized || status == StatusCodeUndefined || status == StatusCodeInitializing { return false } return true } // Status is the return struct for the status API endpoint type Status struct { Status StatusCode `json:"status"` Proof string `json:"proof"` PubData string `json:"pubData"` } // ErrorServer is the return struct for an API error type ErrorServer struct { Status StatusCode `json:"status"` Message string `json:"msg"` } // Error message for ErrorServer func (e ErrorServer) Error() string { return fmt.Sprintf("server proof status (%v): %v", e.Status, e.Message) } type apiMethod string const ( // GET is an HTTP GET GET apiMethod = "GET" // POST is an HTTP POST with maybe JSON body POST apiMethod = "POST" ) // ProofServerClient contains the data related to a ProofServerClient type ProofServerClient struct { URL string client *sling.Sling pollInterval time.Duration } // NewProofServerClient creates a new ServerProof func NewProofServerClient(URL string, pollInterval time.Duration) *ProofServerClient { if URL[len(URL)-1] != '/' { URL += "/" } client := sling.New().Base(URL) return &ProofServerClient{URL: URL, client: client, pollInterval: pollInterval} } func (p *ProofServerClient) apiRequest(ctx context.Context, method apiMethod, path string, body interface{}, ret interface{}) error { path = strings.TrimPrefix(path, "/") var errSrv ErrorServer var req *http.Request var err error switch method { case GET: req, err = p.client.New().Get(path).Request() case POST: req, err = p.client.New().Post(path).BodyJSON(body).Request() default: return tracerr.Wrap(fmt.Errorf("invalid http method: %v", method)) } if err != nil { return tracerr.Wrap(err) } res, err := p.client.Do(req.WithContext(ctx), ret, &errSrv) if err != nil { return tracerr.Wrap(err) } defer res.Body.Close() //nolint:errcheck if !(200 <= res.StatusCode && res.StatusCode < 300) { return tracerr.Wrap(errSrv) } return nil } func (p *ProofServerClient) apiStatus(ctx context.Context) (*Status, error) { var status Status return &status, tracerr.Wrap(p.apiRequest(ctx, GET, "/status", nil, &status)) } func (p *ProofServerClient) apiCancel(ctx context.Context) error { return tracerr.Wrap(p.apiRequest(ctx, POST, "/cancel", nil, nil)) } func (p *ProofServerClient) apiInput(ctx context.Context, zkInputs *common.ZKInputs) error { return tracerr.Wrap(p.apiRequest(ctx, POST, "/input", zkInputs, nil)) } // CalculateProof sends the *common.ZKInputs to the ServerProof to compute the // Proof func (p *ProofServerClient) CalculateProof(ctx context.Context, zkInputs *common.ZKInputs) error { return tracerr.Wrap(p.apiInput(ctx, zkInputs)) } // GetProof retreives the Proof and Public Data (public inputs) from the // ServerProof, blocking until the proof is ready. func (p *ProofServerClient) GetProof(ctx context.Context) (*Proof, []*big.Int, error) { if err := p.WaitReady(ctx); err != nil { return nil, nil, tracerr.Wrap(err) } status, err := p.apiStatus(ctx) if err != nil { return nil, nil, tracerr.Wrap(err) } if status.Status == StatusCodeSuccess { var proof Proof if err := json.Unmarshal([]byte(status.Proof), &proof); err != nil { return nil, nil, tracerr.Wrap(err) } var pubInputs PublicInputs if err := json.Unmarshal([]byte(status.PubData), &pubInputs); err != nil { return nil, nil, tracerr.Wrap(err) } return &proof, pubInputs, nil } return nil, nil, tracerr.Wrap(fmt.Errorf("status != StatusCodeSuccess, status = %v", status.Status)) } // Cancel cancels any current proof computation func (p *ProofServerClient) Cancel(ctx context.Context) error { return tracerr.Wrap(p.apiCancel(ctx)) } // WaitReady waits until the serverProof is ready func (p *ProofServerClient) WaitReady(ctx context.Context) error { for { status, err := p.apiStatus(ctx) if err != nil { return tracerr.Wrap(err) } if !status.Status.IsInitialized() { return tracerr.Wrap(fmt.Errorf("Proof Server is not initialized")) } if status.Status.IsReady() { return nil } select { case <-ctx.Done(): return tracerr.Wrap(common.ErrDone) case <-time.After(p.pollInterval): } } } // MockClient is a mock ServerProof to be used in tests. It doesn't calculate anything type MockClient struct { counter int64 Delay time.Duration } // CalculateProof sends the *common.ZKInputs to the ServerProof to compute the // Proof func (p *MockClient) CalculateProof(ctx context.Context, zkInputs *common.ZKInputs) error { return nil } // GetProof retreives the Proof from the ServerProof func (p *MockClient) GetProof(ctx context.Context) (*Proof, []*big.Int, error) { // Simulate a delay select { case <-time.After(p.Delay): //nolint:gomnd i := p.counter * 100 //nolint:gomnd p.counter++ return &Proof{ PiA: [3]*big.Int{ big.NewInt(i), big.NewInt(i + 1), big.NewInt(1), //nolint:gomnd }, PiB: [3][2]*big.Int{ {big.NewInt(i + 2), big.NewInt(i + 3)}, //nolint:gomnd {big.NewInt(i + 4), big.NewInt(i + 5)}, //nolint:gomnd {big.NewInt(1), big.NewInt(0)}, //nolint:gomnd }, PiC: [3]*big.Int{ big.NewInt(i + 6), big.NewInt(i + 7), big.NewInt(1), //nolint:gomnd }, Protocol: "groth", }, []*big.Int{big.NewInt(i + 42)}, //nolint:gomnd nil case <-ctx.Done(): return nil, nil, tracerr.Wrap(common.ErrDone) } } // Cancel cancels any current proof computation func (p *MockClient) Cancel(ctx context.Context) error { // Simulate a delay select { case <-time.After(80 * time.Millisecond): //nolint:gomnd return nil case <-ctx.Done(): return tracerr.Wrap(common.ErrDone) } } // WaitReady waits until the prover is ready func (p *MockClient) WaitReady(ctx context.Context) error { // Simulate a delay select { case <-time.After(200 * time.Millisecond): //nolint:gomnd return nil case <-ctx.Done(): return tracerr.Wrap(common.ErrDone) } }