// Copyright 2021 Google LLC. All Rights Reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // Package http is a simple client for interacting with witnesses over HTTP. package http import ( "bytes" "context" "encoding/json" "errors" "fmt" "io" "net/http" "net/url" "os" wit_api "github.com/google/certificate-transparency-go/internal/witness/api" ) // ErrSTHTooOld is returned if the STH passed to Update needs to be updated. var ErrSTHTooOld = errors.New("STH too old") // Witness consists of the witness' URL and signature verifier. type Witness struct { URL *url.URL } // GetLatestSTH returns a recent STH from the witness for the specified log ID. func (w Witness) GetLatestSTH(ctx context.Context, logID string) ([]byte, error) { u, err := w.URL.Parse(fmt.Sprintf(wit_api.HTTPGetSTH, url.PathEscape(logID))) if err != nil { return nil, fmt.Errorf("failed to parse URL: %v", err) } req, err := http.NewRequest("GET", u.String(), nil) if err != nil { return nil, fmt.Errorf("failed to create request: %v", err) } resp, err := http.DefaultClient.Do(req.WithContext(ctx)) if err != nil { return nil, fmt.Errorf("failed to do http request: %v", err) } defer resp.Body.Close() if resp.StatusCode == 404 { return nil, os.ErrNotExist } else if resp.StatusCode != 200 { return nil, fmt.Errorf("bad status response: %s", resp.Status) } return io.ReadAll(resp.Body) } // Update attempts to clock the witness forward for the given logID. // The latest signed STH will be returned if this succeeds, or if the error is // http.ErrSTHTooOld. In all other cases no STH should be expected. func (w Witness) Update(ctx context.Context, logID string, sth []byte, proof [][]byte) ([]byte, error) { reqBody, err := json.MarshalIndent(&wit_api.UpdateRequest{ STH: sth, Proof: proof, }, "", " ") if err != nil { return nil, fmt.Errorf("failed to marshal update request: %v", err) } u, err := w.URL.Parse(fmt.Sprintf(wit_api.HTTPUpdate, url.PathEscape(logID))) if err != nil { return nil, fmt.Errorf("failed to parse URL: %v", err) } req, err := http.NewRequest("PUT", u.String(), bytes.NewReader(reqBody)) if err != nil { return nil, fmt.Errorf("failed to create request: %v", err) } resp, err := http.DefaultClient.Do(req.WithContext(ctx)) if err != nil { return nil, fmt.Errorf("failed to do http request: %v", err) } defer resp.Body.Close() body, err := io.ReadAll(resp.Body) if err != nil { return nil, fmt.Errorf("failed to read body: %v", err) } if resp.StatusCode != 200 { if resp.StatusCode == 409 { return body, ErrSTHTooOld } return nil, fmt.Errorf("bad status response (%s): %q", resp.Status, body) } return body, nil }