added start on stfe client

ChecksumV1 entries can be submitted using client-side ed25519
signatures.  The resulting SignedDebugInfoV1 is then verified using the
log's announced signature scheme and public key (currently only ed25519).

1 files changed, 139 insertions, 0 deletions

diff --git a/client/client.go b/client/client.go
new file mode 100644
index 0000000..e1663a0
--- /dev/null
+++ b/client/client.go
@@ -0,0 +1,139 @@
+package client
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+
+	"crypto/ed25519"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/golang/glog"
+	"github.com/system-transparency/stfe"
+	"github.com/system-transparency/stfe/server/descriptor"
+	"golang.org/x/net/context/ctxhttp"
+)
+
+type Client struct {
+	Log        *descriptor.Log
+	Client     *http.Client
+	Chain      []*x509.Certificate
+	PrivateKey *ed25519.PrivateKey
+}
+
+// NewClient returns a new log client
+func NewClient(log *descriptor.Log, client *http.Client, chain []*x509.Certificate, privateKey *ed25519.PrivateKey) *Client {
+	return &Client{
+		Log:        log,
+		Chain:      chain,
+		Client:     client,
+		PrivateKey: privateKey,
+	}
+}
+
+func (c *Client) AddEntry(ctx context.Context, name, checksum []byte) (*stfe.StItem, error) {
+	glog.V(3).Info("creating add-entry request")
+	leaf, err := stfe.NewChecksumV1(name, checksum).Marshal()
+	if err != nil {
+		return nil, fmt.Errorf("failed marshaling StItem: %v", err)
+	}
+	data, err := json.Marshal(struct {
+		Item      string   `json:"item"`
+		Scheme    uint16   `json:"signature_scheme"`
+		Signature string   `json:"signature"`
+		Chain     []string `json:"chain"`
+	}{
+		Item:      base64.StdEncoding.EncodeToString(leaf),
+		Scheme:    uint16(tls.Ed25519),
+		Signature: base64.StdEncoding.EncodeToString(ed25519.Sign(*c.PrivateKey, serialized)),
+		Chain:     c.b64Chain(),
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed creating post data: %v", err)
+	}
+	// TODO: make http(s) config option
+	req, err := http.NewRequest("POST", "http://"+c.Log.BaseUrl+"/add-entry", bytes.NewBuffer(data))
+	if err != nil {
+		return nil, fmt.Errorf("failed creating http request: %v", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	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)
+	}
+
+	if item.Format != stfe.StFormatSignedDebugInfoV1 {
+		return nil, fmt.Errorf("bad StItem format: %v", item.Format)
+	}
+	if err := item.SignedDebugInfoV1.Verify(c.Log.Scheme, c.Log.PublicKey, serialized); err != nil {
+		return nil, fmt.Errorf("bad SignedDebugInfoV1 signature: %v", err)
+	}
+	return &item, nil
+}
+
+func (c *Client) doRequest(ctx context.Context, req *http.Request, out interface{}) error {
+	glog.V(3).Infof("sending request: %v %v", req.Method, req.URL)
+	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
+}
+
+func (c *Client) GetSth(ctx context.Context) (*stfe.StItem, error) {
+	glog.V(2).Info("creating get-sth request")
+	return nil, fmt.Errorf("TODO")
+}
+
+func (c *Client) GetConsistencyProof(ctx context.Context, first, second uint64) (*stfe.StItem, error) {
+	glog.V(2).Info("creating get-consistency-proof request")
+	return nil, fmt.Errorf("TODO")
+}
+
+func (c *Client) GetProofByHash(ctx context.Context, treeSize uint64, hash []byte) (*stfe.StItem, error) {
+	glog.V(2).Info("creating get-proof-by-hash request")
+	return nil, fmt.Errorf("TODO")
+}
+
+func (c *Client) GetEntries(ctx context.Context, start, end uint64) (*stfe.StItem, error) {
+	glog.V(2).Info("creating get-entries request")
+	return nil, fmt.Errorf("TODO")
+}
+
+func (c *Client) GetAnchors(ctx context.Context, start, end uint64) ([]*x509.Certificate, error) {
+	glog.V(2).Info("creating get-anchors request")
+	return nil, fmt.Errorf("TODO")
+}
+
+func (c *Client) b64Chain() []string {
+	chain := make([]string, 0, len(c.Chain))
+	for _, cert := range c.Chain {
+		chain = append(chain, base64.StdEncoding.EncodeToString(cert.Raw))
+	}
+	return chain
+}