package client import ( "bytes" "context" "fmt" "crypto/ed25519" "encoding/base64" "encoding/json" "io/ioutil" "net/http" "github.com/golang/glog" "github.com/google/trillian/merkle/rfc6962" "github.com/system-transparency/stfe" "github.com/system-transparency/stfe/descriptor" "github.com/system-transparency/stfe/namespace" "golang.org/x/net/context/ctxhttp" ) // Client is an HTTP(S) client that talks to an ST log type Client struct { Log *descriptor.Log Client *http.Client PrivateKey *ed25519.PrivateKey Namespace *namespace.Namespace useHttp bool } // NewClient returns a new log client. // // Note: private key can be ommied if no write APIs are used. func NewClient(log *descriptor.Log, client *http.Client, useHttp bool, privateKey *ed25519.PrivateKey) (*Client, error) { c := &Client{ Log: log, Client: client, PrivateKey: privateKey, useHttp: useHttp, } if privateKey != nil { var err error c.Namespace, err = namespace.NewNamespaceEd25519V1([]byte(privateKey.Public().(ed25519.PublicKey))) if err != nil { return nil, fmt.Errorf("failed creating namespace: %v", err) } } return c, nil } // AddEntry creates, signs, and adds a new ChecksumV1 entry to the log func (c *Client) AddEntry(ctx context.Context, name, checksum []byte) (*stfe.StItem, error) { leaf, err := stfe.NewChecksumV1(name, checksum, c.Namespace).Marshal() if err != nil { return nil, fmt.Errorf("failed marshaling StItem: %v", err) } data, err := json.Marshal(stfe.AddEntryRequest{ Item: leaf, Signature: ed25519.Sign(*c.PrivateKey, leaf), }) if err != nil { return nil, fmt.Errorf("failed creating post data: %v", err) } glog.V(3).Infof("created post data: %s", string(data)) url := stfe.EndpointAddEntry.Path(c.protocol() + c.Log.BaseUrl) req, err := http.NewRequest("POST", url, bytes.NewBuffer(data)) if err != nil { return nil, fmt.Errorf("failed creating http request: %v", err) } req.Header.Set("Content-Type", "application/json") glog.V(2).Infof("created http request: %s %s", req.Method, req.URL) item, err := c.doRequestWithStItemResponse(ctx, req) if err != nil { return nil, err } if item.Format != stfe.StFormatSignedDebugInfoV1 { return nil, fmt.Errorf("bad StItem format: %v", item.Format) } if ns, err := c.Log.Namespace(); err != nil { return nil, fmt.Errorf("invalid log namespace: %v", err) } else if err := ns.Verify(leaf, item.SignedDebugInfoV1.Signature); err != nil { return nil, fmt.Errorf("bad SignedDebugInfoV1 signature: %v", err) } return item, nil } // GetSth fetches and verifies the most recent STH. func (c *Client) GetSth(ctx context.Context) (*stfe.StItem, error) { url := stfe.EndpointGetSth.Path(c.protocol() + c.Log.BaseUrl) req, err := http.NewRequest("GET", url, nil) if err != nil { return nil, fmt.Errorf("failed creating http request: %v", err) } glog.V(2).Infof("created http request: %s %s", req.Method, req.URL) item, err := c.doRequestWithStItemResponse(ctx, req) if err != nil { return nil, err } if item.Format != stfe.StFormatSignedTreeHeadV1 { return nil, fmt.Errorf("bad StItem format: %v", item.Format) } th, err := item.SignedTreeHeadV1.TreeHead.Marshal() if err != nil { return nil, fmt.Errorf("failed marshaling tree head: %v", err) } if ns, err := c.Log.Namespace(); err != nil { return nil, fmt.Errorf("bad public key: %v", err) } else if err := ns.Verify(th, item.SignedTreeHeadV1.Signature); err != nil { return nil, fmt.Errorf("bad SignedTreeHeadV1 signature: %v", err) } return item, nil } // GetConsistencyProof fetches and verifies a consistency proof between two // STHs. func (c *Client) GetConsistencyProof(ctx context.Context, first, second *stfe.StItem) (*stfe.StItem, error) { url := stfe.EndpointGetConsistencyProof.Path(c.protocol() + c.Log.BaseUrl) req, err := http.NewRequest("GET", url, nil) if err != nil { return nil, fmt.Errorf("failed creating http request: %v", err) } req.Header.Set("Content-Type", "application/json") q := req.URL.Query() q.Add("first", fmt.Sprintf("%d", first.SignedTreeHeadV1.TreeHead.TreeSize)) q.Add("second", fmt.Sprintf("%d", second.SignedTreeHeadV1.TreeHead.TreeSize)) req.URL.RawQuery = q.Encode() glog.V(2).Infof("created http request: %s %s", req.Method, req.URL) item, err := c.doRequestWithStItemResponse(ctx, req) if err != nil { return nil, err } if item.Format != stfe.StFormatConsistencyProofV1 { return nil, fmt.Errorf("bad StItem format: %v", item.Format) } if err := VerifyConsistencyProofV1(item, first, second); err != nil { return nil, fmt.Errorf("bad consistency proof: %v", err) } return item, nil } // GetProofByHash fetches and verifies an inclusion proof for a leaf against an // STH. func (c *Client) GetProofByHash(ctx context.Context, treeSize uint64, rootHash, leaf []byte) (*stfe.StItem, error) { leafHash := rfc6962.DefaultHasher.HashLeaf(leaf) url := stfe.EndpointGetProofByHash.Path(c.protocol() + c.Log.BaseUrl) req, err := http.NewRequest("GET", url, nil) if err != nil { return nil, fmt.Errorf("failed creating http request: %v", err) } req.Header.Set("Content-Type", "application/json") q := req.URL.Query() q.Add("hash", base64.StdEncoding.EncodeToString(leafHash)) q.Add("tree_size", fmt.Sprintf("%d", treeSize)) req.URL.RawQuery = q.Encode() glog.V(2).Infof("created http request: %s %s", req.Method, req.URL) item, err := c.doRequestWithStItemResponse(ctx, req) if err != nil { return nil, err } if item.Format != stfe.StFormatInclusionProofV1 { return nil, fmt.Errorf("bad StItem format: %v", item.Format) } if err := VerifyInclusionProofV1(item, rootHash, leafHash); err != nil { return nil, fmt.Errorf("bad inclusion proof: %v", err) } return item, nil } // GetEntries fetches a range of entries from the log, verifying that they are // of type checksum_v1 and signed by a valid certificate chain in the appendix. // Fewer entries may be returned if too large range, in which case the end is // truncated. // // Note that a certificate chain is considered valid if it is chained correctly. // In other words, the caller may want to check whether the anchor is trusted. func (c *Client) GetEntries(ctx context.Context, start, end uint64) ([]*stfe.GetEntryResponse, error) { url := stfe.EndpointGetEntries.Path(c.protocol() + c.Log.BaseUrl) req, err := http.NewRequest("GET", url, nil) if err != nil { return nil, fmt.Errorf("failed creating http request: %v", err) } req.Header.Set("Content-Type", "application/json") q := req.URL.Query() q.Add("start", fmt.Sprintf("%d", start)) q.Add("end", fmt.Sprintf("%d", end)) req.URL.RawQuery = q.Encode() glog.V(2).Infof("created http request: %s %s", req.Method, req.URL) var rsp []*stfe.GetEntryResponse if err := c.doRequest(ctx, req, &rsp); err != nil { return nil, err } for _, entry := range rsp { var item stfe.StItem if err := item.Unmarshal(entry.Item); err != nil { return nil, fmt.Errorf("unmarshal failed: %v (%v)", err, entry) } if item.Format != stfe.StFormatChecksumV1 { return nil, fmt.Errorf("bad StFormat: %v (%v)", err, entry) } if err := item.ChecksumV1.Namespace.Verify(entry.Item, entry.Signature); err != nil { // TODO: only works if full vk in namespace return nil, fmt.Errorf("bad signature: %v (%v)", err, entry) } } return rsp, nil } // GetNamespaces fetches the log's trusted namespaces. func (c *Client) GetNamespaces(ctx context.Context) ([][]byte, error) { url := stfe.EndpointGetAnchors.Path(c.protocol() + c.Log.BaseUrl) // TODO: update GetAnchors => GetNamespaces req, err := http.NewRequest("GET", url, nil) if err != nil { return nil, fmt.Errorf("failed creating http request: %v", err) } var rsp [][]byte if err := c.doRequest(ctx, req, &rsp); err != nil { return nil, err } return rsp, nil } // doRequest sends an HTTP request and decodes the resulting json body into out func (c *Client) doRequest(ctx context.Context, req *http.Request, out interface{}) error { rsp, err := ctxhttp.Do(ctx, c.Client, req) if err != nil { return fmt.Errorf("http request failed: %v", err) } body, err := ioutil.ReadAll(rsp.Body) rsp.Body.Close() if err != nil { return fmt.Errorf("http body read failed: %v", err) } if rsp.StatusCode != http.StatusOK { return fmt.Errorf("http status code not ok: %v", rsp.StatusCode) } if err := json.Unmarshal(body, out); err != nil { return fmt.Errorf("failed decoding json body: %v", err) } return nil } // // doRequestWithStItemResponse sends an HTTP request and returns a decoded // StItem that the resulting HTTP response contained json:ed and marshaled func (c *Client) doRequestWithStItemResponse(ctx context.Context, req *http.Request) (*stfe.StItem, error) { var itemStr string if err := c.doRequest(ctx, req, &itemStr); err != nil { return nil, err } b, err := base64.StdEncoding.DecodeString(itemStr) if err != nil { return nil, fmt.Errorf("failed decoding base64 body: %v", err) } var item stfe.StItem if err := item.Unmarshal(b); err != nil { return nil, fmt.Errorf("failed decoding StItem: %v", err) } glog.V(3).Infof("got StItem: %s", item) return &item, nil } // protocol returns a protocol string that preceeds the log's base url func (c *Client) protocol() string { if c.useHttp { return "http://" } return "https://" }