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|
package client
import (
"bytes"
"context"
"crypto"
"flag"
"fmt"
"reflect"
"crypto/ed25519"
"crypto/rand"
"encoding/base64"
"io/ioutil"
"net/http"
"github.com/golang/glog"
"github.com/google/trillian/merkle/rfc6962"
"github.com/system-transparency/stfe"
"github.com/system-transparency/stfe/types"
"golang.org/x/net/context/ctxhttp"
)
var (
logId = flag.String("log_id", "AAEsY0retj4wa3S2fjsOCJCTVHab7ipEiMdqtW1uJ6Jvmg==", "base64-encoded log identifier")
logUrl = flag.String("log_url", "http://localhost:6965/st/v1", "log url")
ed25519_sk = flag.String("ed25519_sk", "d8i6nud7PS1vdO0sIk9H+W0nyxbM63Y3/mSeUPRafWaFh8iH8QXvL7NaAYn2RZPrnEey+FdpmTYXE47OFO70eg==", "base64-encoded ed25519 signing key")
)
type Client struct {
HttpClient *http.Client
Signer crypto.Signer // client's private identity
Namespace *types.Namespace // client's public identity
Log *Descriptor // log's public identity
}
type Descriptor struct {
Namespace *types.Namespace // log identifier is a namespace
Url string // log url, e.g., http://example.com/st/v1
}
func NewClientFromFlags() (*Client, error) {
var err error
c := Client{
HttpClient: &http.Client{},
}
if len(*ed25519_sk) != 0 {
sk, err := base64.StdEncoding.DecodeString(*ed25519_sk)
if err != nil {
return nil, fmt.Errorf("ed25519_sk: DecodeString: %v", err)
}
c.Signer = ed25519.PrivateKey(sk)
c.Namespace, err = types.NewNamespaceEd25519V1([]byte(ed25519.PrivateKey(sk).Public().(ed25519.PublicKey)))
if err != nil {
return nil, fmt.Errorf("ed25519_vk: NewNamespaceEd25519V1: %v", err)
}
}
if c.Log, err = NewDescriptorFromFlags(); err != nil {
return nil, fmt.Errorf("NewDescriptorFromFlags: %v", err)
}
return &c, nil
}
func NewDescriptorFromFlags() (*Descriptor, error) {
b, err := base64.StdEncoding.DecodeString(*logId)
if err != nil {
return nil, fmt.Errorf("LogId: DecodeString: %v", err)
}
var namespace types.Namespace
if err := types.Unmarshal(b, &namespace); err != nil {
return nil, fmt.Errorf("LogId: Unmarshal: %v", err)
}
return &Descriptor{
Namespace: &namespace,
Url: *logUrl,
}, nil
}
// AddEntry signs and submits a checksum_v1 entry to the log. Outputs the
// resulting leaf-hash on success, which can be used to verify inclusion.
func (c *Client) AddEntry(ctx context.Context, data *types.ChecksumV1) ([]byte, error) {
msg, err := types.Marshal(*data)
if err != nil {
return nil, fmt.Errorf("failed marshaling ChecksumV1: %v", err)
}
sig, err := c.Signer.Sign(rand.Reader, msg, crypto.Hash(0))
if err != nil {
return nil, fmt.Errorf("failed signing ChecksumV1: %v", err)
}
leaf, err := types.Marshal(*types.NewSignedChecksumV1(data, &types.SignatureV1{
Namespace: *c.Namespace,
Signature: sig,
}))
if err != nil {
return nil, fmt.Errorf("failed marshaling SignedChecksumV1: %v", err)
}
glog.V(9).Infof("signed: %v", data)
url := stfe.EndpointAddEntry.Path(c.Log.Url)
req, err := http.NewRequest("POST", url, bytes.NewBuffer(leaf))
if err != nil {
return nil, fmt.Errorf("failed creating http request: %v", err)
}
req.Header.Set("Content-Type", "application/octet-stream")
glog.V(3).Infof("created http request: %s %s", req.Method, req.URL)
if rsp, err := c.doRequest(ctx, req); err != nil {
return nil, fmt.Errorf("doRequest: %v", err)
} else if len(rsp) != 0 {
return nil, fmt.Errorf("extra data: %v", err)
}
glog.V(3).Infof("add-entry succeded")
return rfc6962.DefaultHasher.HashLeaf(leaf), nil
}
func (c *Client) GetLatestSth(ctx context.Context) (*types.StItem, error) {
url := stfe.EndpointGetLatestSth.Path(c.Log.Url)
req, err := http.NewRequest("GET", url, nil)
if err != nil {
return nil, fmt.Errorf("failed creating http request: %v", err)
}
glog.V(3).Infof("created http request: %s %s", req.Method, req.URL)
item, err := c.doRequestWithStItemResponse(ctx, req)
if err != nil {
return nil, err
}
if got, want := item.Format, types.StFormatSignedTreeHeadV1; got != want {
return nil, fmt.Errorf("unexpected StItem format: %v", got)
}
if got, want := &item.SignedTreeHeadV1.Signature.Namespace, c.Log.Namespace; !reflect.DeepEqual(got, want) {
return nil, fmt.Errorf("unexpected log id: %v", want)
}
th, err := types.Marshal(item.SignedTreeHeadV1.TreeHead)
if err != nil {
return nil, fmt.Errorf("failed marshaling tree head: %v", err)
}
if err := c.Log.Namespace.Verify(th, item.SignedTreeHeadV1.Signature.Signature); err != nil {
return nil, fmt.Errorf("signature verification failed: %v", err)
}
glog.V(3).Infof("verified sth")
return item, nil
}
// doRequest sends an HTTP request and outputs the raw body
func (c *Client) doRequest(ctx context.Context, req *http.Request) ([]byte, error) {
rsp, err := ctxhttp.Do(ctx, c.HttpClient, req)
if err != nil {
return nil, fmt.Errorf("no response: %v", err)
}
defer rsp.Body.Close()
if got, want := rsp.StatusCode, http.StatusOK; got != want {
return nil, fmt.Errorf("bad http status: %v", got)
}
body, err := ioutil.ReadAll(rsp.Body)
if err != nil {
return nil, fmt.Errorf("cannot read body: %v", err)
}
return body, 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) (*types.StItem, error) {
body, err := c.doRequest(ctx, req)
if err != nil {
return nil, err
}
var item types.StItem
if err := types.Unmarshal(body, &item); err != nil {
return nil, fmt.Errorf("failed decoding StItem: %v", err)
}
glog.V(9).Infof("got StItem: %v", item)
return &item, nil
}
|
